Journal articles: 'Delbrueckii subsp'

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Serror, Pascale, Takashi Sasaki, S. Dusko Ehrlich, and Emmanuelle Maguin. "Electrotransformation of Lactobacillus delbrueckii subsp. bulgaricus and L. delbrueckii subsp. lactis with Various Plasmids." Applied and Environmental Microbiology 68, no. 1 (January 2002): 46–52. http://dx.doi.org/10.1128/aem.68.1.46-52.2002.

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ABSTRACT We describe, for the first time, a detailed electroporation procedure for Lactobacillus delbrueckii. Three L. delbrueckii strains were successfully transformed. Under optimal conditions, the transformation efficiency was 104 transformants per μg of DNA. Using this procedure, we identified several plasmids able to replicate in L. delbrueckii and integrated an integrative vector based on phage integrative elements into the L. delbrueckii subsp. bulgaricus chromosome. These vectors provide a good basis for developing molecular tools for L. delbrueckii and open the field of genetic studies in L. delbrueckii.

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Tanigawa, Kana, and Koichi Watanabe. "Multilocus sequence typing reveals a novel subspeciation of Lactobacillus delbrueckii." Microbiology 157, no. 3 (March 1, 2011): 727–38. http://dx.doi.org/10.1099/mic.0.043240-0.

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Currently, the species Lactobacillus delbrueckii is divided into four subspecies, L. delbrueckii subsp. delbrueckii, L. delbrueckii subsp. bulgaricus, L. delbrueckii subsp. indicus and L. delbrueckii subsp. lactis. These classifications were based mainly on phenotypic identification methods and few studies have used genotypic identification methods. As a result, these subspecies have not yet been reliably delineated. In this study, the four subspecies of L. delbrueckii were discriminated by phenotype and by genotypic identification [amplified-fragment length polymorphism (AFLP) and multilocus sequence typing (MLST)] methods. The MLST method developed here was based on the analysis of seven housekeeping genes (fusA, gyrB, hsp60, ileS, pyrG, recA and recG). The MLST method had good discriminatory ability: the 41 strains of L. delbrueckii examined were divided into 34 sequence types, with 29 sequence types represented by only a single strain. The sequence types were divided into eight groups. These groups could be discriminated as representing different subspecies. The results of the AFLP and MLST analyses were consistent. The type strain of L. delbrueckii subsp. delbrueckii, YIT 0080T, was clearly discriminated from the other strains currently classified as members of this subspecies, which were located close to strains of L. delbrueckii subsp. lactis. The MLST scheme developed in this study should be a useful tool for the identification of strains of L. delbrueckii to the subspecies level.

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Lapierre, Luciane, Beat Mollet, and Jacques-Edouard Germond. "Regulation and Adaptive Evolution of Lactose Operon Expression in Lactobacillus delbrueckii." Journal of Bacteriology 184, no. 4 (February 15, 2002): 928–35. http://dx.doi.org/10.1128/jb.184.4.928-935.2002.

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ABSTRACT Lactobacillus delbrueckii subsp. bulgaricus and L. delbrueckii subsp. lactis are both used in the dairy industry as homofermentative lactic acid bacteria in the production of fermented milk products. After selective pressure for the fast fermentation of milk in the manufacture of yogurts, L. delbrueckii subsp. bulgaricus loses its ability to regulate lac operon expression. A series of mutations led to the constitutive expression of the lac genes. A complex of insertion sequence (IS) elements (ISL4 inside ISL5), inserted at the border of the lac promoter, induced the loss of the palindromic structure of one of the operators likely involved in the binding of regulatory factors. A lac repressor gene was discovered downstream of the β-galactosidase gene of L. delbrueckii subsp. lactis and was shown to be inactivated by several mutations in L. delbrueckii subsp. bulgaricus. Regulatory mechanisms of the lac gene expression of L. delbrueckii subsp. bulgaricus and L. delbrueckii subsp. lactis were compared by heterologous expression in Lactococcus lactis of the two lac promoters in front of a reporter gene (β-glucuronidase) in the presence or absence of the lac repressor gene. Insertion of the complex of IS elements in the lac promoter of L. delbrueckii subsp. bulgaricus increased the promoter's activity but did not prevent repressor binding; rather, it increased the affinity of the repressor for the promoter. Inactivation of the lac repressor by mutations was then necessary to induce the constitutive expression of the lac genes in L. delbrueckii subsp. bulgaricus.

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Adimpong, David B., Dennis S. Nielsen, Kim I. Sørensen, Finn K. Vogensen, Hagrétou Sawadogo-Lingani, Patrick M. F. Derkx, and Lene Jespersen. "Lactobacillus delbrueckii subsp. jakobsenii subsp. nov., isolated from dolo wort, an alcoholic fermented beverage in Burkina Faso." International Journal of Systematic and Evolutionary Microbiology 63, Pt_10 (October 1, 2013): 3720–26. http://dx.doi.org/10.1099/ijs.0.048769-0.

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Lactobacillus delbrueckii is divided into five subspecies based on phenotypic and genotypic differences. A novel isolate, designated ZN7a-9T, was isolated from malted sorghum wort used for making an alcoholic beverage (dolo) in Burkina Faso. The results of 16S rRNA gene sequencing, DNA–DNA hybridization and peptidoglycan cell-wall structure type analyses indicated that it belongs to the species L. delbrueckii . The genome sequence of isolate ZN7a-9T was determined by Illumina-based sequencing. Multilocus sequence typing (MLST) and split-decomposition analyses were performed on seven concatenated housekeeping genes obtained from the genome sequence of strain ZN7a-9T together with 41 additional L. delbrueckii strains. The results of the MLST and split-decomposition analyses could not establish the exact subspecies of L. delbrueckii represented by strain ZN7a-9T as it clustered with L. delbrueckii strains unassigned to any of the recognized subspecies of L. delbrueckii . Strain ZN7a-9T additionally differed from the recognized type strains of the subspecies of L. delbrueckii with respect to its carbohydrate fermentation profile. In conclusion, the cumulative results indicate that strain ZN7a-9T represents a novel subspecies of L. delbrueckii closely related to Lactobacillus delbrueckii subsp. lactis and Lactobacillus delbrueckii subsp. delbrueckii for which the name Lactobacillus delbrueckii subsp. jakobsenii subsp. nov. is proposed. The type strain is ZN7a-9T = DSM 26046T = LMG 27067T.

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Kudo, Yuko, Kaihei Oki, and Koichi Watanabe. "Lactobacillus delbrueckii subsp. sunkii subsp. nov., isolated from sunki, a traditional Japanese pickle." International Journal of Systematic and Evolutionary Microbiology 62, Pt_11 (November 1, 2012): 2643–49. http://dx.doi.org/10.1099/ijs.0.037051-0.

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Although four strains of bacteria isolated from sunki, a traditional Japanese, non-salted pickle, were initially identified as Lactobacillus delbrueckii , the molecular and phenotypic characteristics of the strains did not match those of any of the four recognized subspecies of L. delbrueckii . Together, the results of phenotypic characterization, DNA–DNA hybridizations (in which the relatedness values between the novel strains and type strains of the recognized subspecies of L. delbrueckii were all >88.7 %) and 16S rRNA gene sequence, amplified fragment length polymorphism (AFLP) and whole-cell MALDI-TOF/MS spectral pattern analyses indicated that the four novel strains represented a single, novel subspecies, for which the name Lactobacillus delbrueckii subsp. sunkii subsp. nov. is proposed. The type strain is YIT 11221T ( = JCM 17838T = DSM 24966T).

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Dellaglio, Franco, Giovanna E. Felis, Anna Castioni, Sandra Torriani, and Jacques-Edouard Germond. "Lactobacillus delbrueckii subsp. indicus subsp. nov., isolated from Indian dairy products." International Journal of Systematic and Evolutionary Microbiology 55, no. 1 (January 1, 2005): 401–4. http://dx.doi.org/10.1099/ijs.0.63067-0.

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Four strains isolated from Indian dairy products and initially identified as Lactobacillus delbrueckii could not be assigned to a definite subspecies because molecular identification and phenotypic traits did not agree with those of recognized subspecies of L. delbrueckii. Hybridization of total DNA (78–86 % against type strains of the other three subspecies), AFLP and RAPD-PCR fingerprints, phylogenetic analysis based on 16S rRNA gene sequences and sequence analysis of two coding genes (recA and hsp60), together with phenotypic profiles, indicated that the four strains form a coherent cluster and represent a novel subspecies, for which the name Lactobacillus delbrueckii subsp. indicus subsp. nov. is proposed. The type strain is NCC725T (=LMG 22083T=DSM 15996T).

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Zhao, Xiu Hong, Jie Zeng, Hai Yan Gao, Chang Biao Li, and Chang Jiang Liu. "Cloning, Expression and Characterization of β-Glucosidase from L. Delbrueckii Subsp. Delbrueckii in Escherichia coli." Advanced Materials Research 301-303 (July 2011): 347–51. http://dx.doi.org/10.4028/www.scientific.net/amr.301-303.347.

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Gene encoding β-glucosidase was amplified through PCR by using the genome DNA extracted from L .delbrueckii subsp. delbrueckii as a template. The gene encoding β-glucosidase was inserted into a prokaryotic expression vector pET-28a(+) and expressed in E.coli strain BL21(DE3). The gene encoding β-glucosidase was of 1380bp. The nucleotide sequence of the gene encoding β-glucosidase from L. delbrueckii subsp. delbrueckii showed as high as 97.9% homology comparing with that from L. delbrueckii subsp. bulgaricus indicating that the gene encoding β-glucosidase is highly conservative. The enzyme activity was about 34U/mg and the molecular weight of β-glucosidase is about 51 kDa analyzed by SDS-polyacrylamide gel electrophoresis.

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Frengova, Ginka I., Emilina D. Simova, Dora M. Beshkova, and Zhelyasko I. Simov. "Exopolysaccharides Produced by Lactic Acid Bacteria of Kefir Grains." Zeitschrift für Naturforschung C 57, no. 9-10 (October 1, 2002): 805–10. http://dx.doi.org/10.1515/znc-2002-9-1009.

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A Lactobacillus delbrueckii subsp. bulgaricus HP1 strain with high exopolysaccharide activity was selected from among 40 strains of lactic acid bacteria, isolated from kefir grains. By associating the Lactobacillus delbrueckii subsp. bulgaricus HP1 strain with Streptococcus thermophilus T15, Lactococcus lactis subsp. lactis C15, Lactobacillus helveticus MP12. and Sacharomyces cerevisiae A13, a kefir starter was formed. The associated cultivation of the lactobacteria and yeast had a positive effect on the exopolysaccharide activity of Lactobacillus delbrueckii subsp. bulgaricus HP1. The maximum exopolysaccharide concentration of the starter culture exceeded the one by the Lactobacillus delbrueckii subsp. bulgaricus HP1 monoculture by approximately 1.7 times, and the time needed to reach the maximum concentration (824.3 mg exopolysacharides/l) was shortened by 6 h. The monomer composition of the exopolysaccharides from the kefir starter culture was represented by glucose and galactose in a 1.0:0.94 ratio, which proves that the polymer synthesized is kefiran.

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Samadlouie, Hamid Reza, Shahrokh Gharanjik, and Zohreh Beygom Tabatabaie. "Optimization of the Production of ε-Poly-L-Lysine by Novel Producer Lactic Acid Bacteria Isolated from Traditional Dairy Products." BioMed Research International 2020 (October 5, 2020): 1–8. http://dx.doi.org/10.1155/2020/2145656.

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New strains of lactic acid bacteria (LAB) were isolated from different traditional dairy products. Six new strains named Lactobacillus delbrueckii strain A01, Lactobacillus delbrueckii subsp. bulgaricus strain D01, Lactobacillus delbrueckii subsp. bulgaricus strain E01, Lactococcus lactis strain G01, Lactobacillus delbrueckii strain C01, and Lactobacillus delbrueckii subsp. bulgaricus strain F01 were identified using 16S rDNA sequencing, morphological and biochemical traits. All strains have been registered in the National Center for Biotechnology Information (NCBI) with accession numbers MN611241.1, MN611300.1, MN611301.1, MN611303.1, MN611241.1, and MN611299.1, respectively. Having found ε-Poly-L-Lysine (ε-PL) in all strains isolated, Lactobacillus delbrueckii strain A01 was identified as an active producer of ε-Poly-L-Lysine (ε-PL). The one-factor-at-a-time method and central composite design were applied to optimize ε-Poly-L-Lysine (ε-PL). A predicted 200 ppm of ε-PL was obtained in the medium containing the lowest level of glucose, 25 g/l, and yeast extract, 6 g/l.

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GIRAFFA, GIORGIO, and DIEGO MORA. "DNA probe for Lactobacillus delbrueckii subsp. lactis." Journal of Dairy Research 66, no. 2 (May 1999): 303–11. http://dx.doi.org/10.1017/s002202999900343x.

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Lactobacilli are of great commercial value because they are widely used as starters in food fermentation. The species Lactobacillus delbrueckii, which comprises the three subspecies bulgaricus, lactis and delbrueckii, is important in dairy products and vegetables. The subspecies bulgaricus is present in yogurt, and subspecies lactis is recovered from whey, starter cultures and cheeses (Stiles & Holzapfel, 1997). It is unusual to recover Lb. delbrueckii subsp. delbrueckii (Lb. delbrueckii) from dairy products, from which Lb. delbrueckii subsp. lactis (Lb. lactis) and subsp. bulgaricus (Lb. bulgaricus) are typically isolated. However, given the similarity of these two latter subspecies, a clear identification of isolates on the basis of phenotype criteria alone is often problematic (Dellaglio, 1989; Millière et al. 1996).The use of DNA probes and methods based on polymerase chain reaction (PCR) have greatly facilitated diagnostic identification of bacteria. For the lactobacilli, DNA probes have been described for Lb. helveticus, Lb. acidophilus, Lb. fermentum, Lb. plantarum and most of the other Lactobacillus species (Pot et al. 1994; Tailliez et al. 1994; Quere et al. 1997). For Lb. delbrueckii, an EcoRI DNA fragment of the plasmid pY85 was used as a probe for this species, although it was not able to discriminate its three subspecies (Delley et al. 1990).In our laboratory, a specific amplification of a DNA fragment of ∼1·7 kbp using universal primers for the amplification of ribosomal RNA (rRNA) genes was found only for dairy isolates of Lb. lactis and not for Lb. bulgaricus, Lb. delbrueckii, Lb. helveticus and Lb. acidophilus (G. Giraffa, P. de Vecchi and L. Rossetti, unpublished results). This prompted us to test the possible use of this fragment as a specific DNA probe for Lb. lactis. To this end, Southern and dot blot hybridization experiments were carried out with total DNA of several strains belonging to different lactic acid bacteria (LAB) species.

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Torriani, Sandra, Giacomo Zapparoli, and Franco Dellaglio. "Use of PCR-Based Methods for Rapid Differentiation of Lactobacillus delbrueckii subsp.bulgaricus and L. delbrueckii subsp.lactis." Applied and Environmental Microbiology 65, no. 10 (October 1, 1999): 4351–56. http://dx.doi.org/10.1128/aem.65.10.4351-4356.1999.

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ABSTRACT Two PCR-based methods, specific PCR and randomly amplified polymorphic DNA PCR (RAPD-PCR), were used for rapid and reliable differentiation of Lactobacillus delbrueckii subsp.bulgaricus and L. delbrueckii subsp.lactis. PCR with a single combination of primers which targeted the proline iminopeptidase (pepIP) gene ofL. delbrueckii subsp. bulgaricus allowed amplification of genomic fragments specific for the two subspecies when either DNA from a single colony or cells extracted from dairy products were used. A numerical analysis of the RAPD-PCR patterns obtained with primer M13 gave results that were consistent with the results of specific PCR for all strains except L. delbrueckii subsp.delbrueckii LMG 6412T, which clustered withL. delbrueckii subsp. lactis strains. In addition, RAPD-PCR performed with primer 1254 provided highly polymorphic profiles and thus was superior for distinguishing individual L. delbrueckii strains.

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Cebeci, Aysun, and G. Candan Gürakan. "Molecular methods for identification of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus using methionine biosynthesis and 16S rRNA genes." Journal of Dairy Research 75, no. 4 (July 14, 2008): 392–98. http://dx.doi.org/10.1017/s0022029908003543.

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Yoghurt and starter culture producers are still searching strains of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus to produce healthier yogurt with longer shelf life, better texture, taste and quality. However, selective identification of Lb. delbrueckii subsp. bulgaricus and Strep. thermophilus from a mixed population using microbiological and biochemical methods is difficult, time consuming and may not be accurate. In this study, a quick, sensitive and accurate method is proposed to identify both Lb. delbrueckii subsp. bulgaricus and Strep. thermophilus using PCR. The method is comprised of two parts. In the first part, methionine biosynthesis genes, known to be present in both species were partially amplified by designed primers (cysmet2F and cysmet2R). Partial amplification of the methionine biosynthesis gene which gives 700 bp fragment resulted in selective identification of Lb. bulgaricus and Strep. thermophilus. All 16 Lb. bulgaricus and 6 Strep. thermophilus isolates assessed by this method gave the expected amplification. On the other hand, further analysis of other closely related species with the same primers have indicated that the same product was also amplified in two more lactobacilli namely, Lb. delbrueckii subsp. lactis and Lb. helveticus species. Thus, in the second part of the method, further differentiation of Lb. delbrueckii subsp. bulgaricus and Strep. thermophilus from each other and these species was achieved using restriction analysis of 16S rRNA gene with EcoRI.

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Do Carmo, A., M. De Oliveira, D. Da Silva, S. Castro, A. Borges, A. De Carvalho, and C. De Moraes. "Genes involved in lactose catabolism and organic acid production during growth of Lactobacillus delbrueckii UFV H2b20 in skimmed milk." Beneficial Microbes 3, no. 1 (March 1, 2012): 23–32. http://dx.doi.org/10.3920/bm2011.0037.

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There are three main reasons for using lactic acid bacteria (LAB) as starter cultures in industrial food fermentation processes: food preservation due to lactic acid production; flavour formation due to a range of organic molecules derived from sugar, lipid and protein catabolism; and probiotic properties attributed to some strains of LAB, mainly of lactobacilli. The aim of this study was to identify some genes involved in lactose metabolism of the probiotic Lactobacillus delbrueckii UFV H2b20, and analyse its organic acid production during growth in skimmed milk. The following genes were identified, encoding the respective enzymes: ldh – lactate dehydrogenase, adhE – Ldb1707 acetaldehyde dehydrogenase, and ccpA-pepR1 – catabolite control protein A. It was observed that L. delbrueckii UFV H2b20 cultivated in different media has the unexpected ability to catabolyse galactose, and to produce high amounts of succinic acid, which was absent in the beginning, raising doubts about the subspecies in question. The phylogenetic analyses showed that this strain can be compared physiologically to L. delbrueckii subsp. bulgaricus and L. delbrueckii subsp. lactis, which are able to degrade lactose and can grow in milk. L. delbrueckii UFV H2b20 sequences have grouped with L. delbrueckii subsp. bulgaricus ATCC 11842 and L. delbrueckii subsp. bulgaricus ATCC BAA-365, strengthening the classification of this probiotic strain in the NCFM group proposed by a previous study. Additionally, L. delbrueckii UFV H2b20 presented an evolutionary pattern closer to that of probiotic Lactobacillus acidophilus NCFM, corroborating the suggestion that this strain might be considered as a new and unusual subspecies among L. delbrueckii subspecies, the first one identified as a probiotic. In addition, its unusual ability to metabolise galactose, which was significantly consumed in the fermentation medium, might be exploited to produce low-browning probiotic Mozzarella cheeses, a desirable property for pizza cheeses.

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ASLIM, BELMA, DERYA ONAL, and YAVUZ BEYATLI. "Factors Influencing Autoaggregation and Aggregation of Lactobacillus delbrueckii subsp. bulgaricus Isolated from Handmade Yogurt." Journal of Food Protection 70, no. 1 (January 1, 2007): 223–27. http://dx.doi.org/10.4315/0362-028x-70.1.223.

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Of 26 Lactobacillus delbrueckii subsp. bulgaricus strains isolated from yogurt, strains B2 and 22, which produce low levels (28 and 21 mg liter−1, respectively) of extracellular polysaccharides (EPSs), and strains B3 and G12, which produce high EPS levels (211 and 175 mg liter−1, respectively), were selected for further study. The two high EPS-producing strains showed a significant autoaggregation and coaggregation ability with Escherichia coli ATCC 11230 (P < 0.05). Moreover, the effect of bile was evaluated on autoaggregation and hydrophobicity. Autoaggregation and hydrophobicity of these L. delbrueckii subsp. bulgaricus strains decreased after treatment with bile. Only the high EPS-producing L. delbrueckii subsp. bulgaricus strain B3 showed greater autoaggregation (80%) and hydrophobicity (86%) than the other strains after bile treatment. When these strains were assessed for the inhibition of E. coli ATCC 11230 in coculture, L. delbrueckii subsp. bulgaricus B3 completely inhibited E. coli during 24 and 48 h of incubation. This investigation showed that a high EPS production and coaggregation ability may be important in the selection of probiotic strains.

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Petry, Sandrine, Satanislav Dusko Ehrlich, and Emmanuelle Maguin. "Exopolysaccharides de Lactobacillus delbrueckii subsp. bulgaricus." Sciences des Aliments 22, no. 1-2 (April 28, 2002): 143–49. http://dx.doi.org/10.3166/sda.22.143-149.

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Zago, Miriam, Angela De Lorentiis, Domenico Carminati, Lucia Comaschi, and Giorgio Giraffa. "Detection and identification of Lactobacillus delbrueckii subsp. lactis bacteriophages by PCR." Journal of Dairy Research 73, no. 2 (January 16, 2006): 146–53. http://dx.doi.org/10.1017/s0022029905001524.

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A sensitive PCR method amplifying an internal fragment of the major tail protein gene was developed to detect Lactobacillus delbrueckii subsp. lactis lytic bacteriophages in undefined, thermophilic whey starters used in Italy for production of Grana and Provolone cheeses. PCR was applied to several lytic Lb. delbrueckii subsp. lactis bacteriophages, which were highly diverse according to restriction analysis and phage host range. PCR detected the presence of phages in two out of 11 cultures, when applied to whey starters for Grana Padano cheese sampled from different cheese plants. The presence of actively growing phages in infected cultures was confirmed by traditional test. The PCR method proved to be useful to screen for the presence of Lb. delbrueckii subsp. lactis phages in thermophilic whey starters.

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ZAVAGLIA, ANDREA GÓMEZ, EDGARDO A. DISALVO, and GRACIELA L. DE ANTONI. "Fatty acid composition and freeze–thaw resistance in lactobacilli." Journal of Dairy Research 67, no. 2 (May 2000): 241–47. http://dx.doi.org/10.1017/s0022029900004179.

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The fatty acid composition and freeze–thaw resistance of eight strains of thermophilic lactobacilli were studied. Seven of these contained the same polar and neutral lipids, the five major components making up 90% of the cellular fatty acid pool being 14[ratio ]0, 16[ratio ]0, 16[ratio ]1, 18[ratio ]1 and C19 cyclopropane (cyc19[ratio ]0). Strain comparison by means of cluster analysis based on the fatty acid ratios using the overlap coefficient revealed two well defined clusters. One was formed by three strains of species Lactobacillus delbrueckii subsp. lactis and Lb. delbrueckii subsp. delbrueckii, the other included five strains of the species Lb. delbrueckii subsp. bulgaricus, Lb. acidophilus and Lb. helveticus. Resistance of strains with a high content of unsaturated fatty acids (66–70%) decreased with increasing cyc19[ratio ]0 concentrations. In contrast, in strains with a low concentration of unsaturated fatty acids (42–49%), increasing cyc19[ratio ]0 levels were associated with increased freeze–thaw resistance.

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Stachelska, Milena Alicja, and Roberta Foligni. "Development of a time-effective and highly specific quantitative real-time polymerase chain reaction assay for the identification of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus in artisanal raw cow’s milk cheese." Acta Veterinaria Brno 87, no. 3 (2018): 301–8. http://dx.doi.org/10.2754/avb201887030301.

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The first objective of this work included the development of real-time polymerase chain reaction (RT-PCR) which is also known as quantitative polymerase chain reaction (qPCR) assays to quantify two species of lactic acid bacteria which play a very important role in cheese ripening: Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus. The second objective was the comparison of qPCR and plate counts of these two species present in raw cow’s milk cheese samples during different stages of ripening. Thirty-three deoxyribonucleic acid (DNA) samples coming from seven different bacterial species, which were phylogenetically related or commonly isolated from raw milk and dairy products, were chosen as positive and negative controls. The qPCR assays showed a high quantification capacity characterised by their linearity (R2 > 0.998), PCR efficiencies which were within the range 78.0–90.0% for L. delbrueckii subsp. bulgaricus, and 93.6–100.5% for S. thermophilus, and quantification limit (103 gene copies/ml for L. delbrueckii subsp. bulgaricus and 10 gene copies/ml for S. thermophilus). The importance of our study is in the monitoring of changes in populations of L. delbrueckii subsp. bulgaricus and S. thermophilus contributing to cheese ripening using the newly designed qPCR assay.

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Ramanovich, N., N. Krauchanka, S. Vasylenko, N. Zhabanos, and N. Furik. "INVESTIGATION OF THE TECHNOLOGICAL ADJUVANT INGREDIENTS INFLUENCE FROM THE PRODUCTION OF FERMENTED MILK DRINKS ON THE GROWTH OF THE LACTOBACILLUS DELBRUECKII SUBSP. LACTIS CULTURES." Topical issues of processing of meat and milk raw materials, no. 14 (December 14, 2020): 20–25. http://dx.doi.org/10.47612/2220-8755-2019-14-20-25.

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We analyzed the change in the active acidity of whole pasteurized milk during its fermentation by the bacteria Lactobacillus delbrueckii subsp. lactis at different temperatures. We have studied the effect of technological adjuvant ingredients (sucrose, carob gum) used for the production of fermented milk drinks on the acid-forming activity of Lactobacillus delbrueckii subsp. lactis, when added them in various concentrations to pasteurized whole milk.

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Laiño, Jonathan Emiliano, Jean Guy LeBlanc, and Graciela Savoy de Giori. "Production of natural folates by lactic acid bacteria starter cultures isolated from artisanal Argentinean yogurts." Canadian Journal of Microbiology 58, no. 5 (May 2012): 581–88. http://dx.doi.org/10.1139/w2012-026.

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Folate is a B-group vitamin that cannot be synthesized by humans and must be obtained exogenously. Although some species of lactic acid bacteria (LAB) can produce folates, little is known about the production of this vitamin by yogurt starter cultures. Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus strains were isolated from artisanal Argentinean yogurts and were grown in folate-free culture medium (FACM) and nonfat milk after which intracellular and extracellular folate production were evaluated. From the initial 92 isolated LAB strains, 4 L. delbrueckii subsp. bulgaricus and 32 S. thermophilus were able to grow in the absence of folate. Lactobacillus delbrueckii subsp. bulgaricus CRL 863 and S. thermophilus CRL 415 and CRL 803 produced the highest extracellular folate levels (from 22.3 to 135 µg/L) in FACM. In nonfat milk, these strains were able to increase the initial folate concentrations by almost 190%. This is the first report where native strains of L. delbrueckii subsp. bulgaricus were shown to produce natural folate. The LAB strains identified in this study could be used in developing novel fermented products bio-enriched in natural folates that could in turn be used as an alternative to fortification with the controversial synthetic chemical folic acid.

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Lick, Sonja, Karsten Drescher, and Knut J. Heller. "Survival of Lactobacillus delbrueckiisubsp. bulgaricus and Streptococcus thermophilusin the Terminal Ileum of Fistulated Göttingen Minipigs." Applied and Environmental Microbiology 67, no. 9 (September 1, 2001): 4137–43. http://dx.doi.org/10.1128/aem.67.9.4137-4143.2001.

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ABSTRACT The ability of Lactobacillus delbrueckii subsp.bulgaricus and Streptococcus thermophilusadministered in yogurt to survive the passage through the upper gastrointestinal tract was investigated with Göttingen minipigs that were fitted with ileum T-cannulas. After ingestion of yogurt containing viable microorganisms, ileostomy samples were collected nearly every hour beginning 3 h after food uptake. Living L. delbrueckii subsp. bulgaricus andS. thermophilus were detected in the magnitude of 106 to 107 per gram of intestinal contents (wet weight) in all animals under investigation. A calculation of the minimum amount of surviving bacteria that had been administered is presented. Total DNA extracted from ileostomy samples was subjected to PCR, which was species specific for L. delbrueckii andS. thermophilus and subspecies specific for L. delbrueckii subsp. bulgaricus. All three bacterial groups could be detected by PCR after yogurt uptake but not after uptake of a semisynthetic diet. One pig apparently had developed an endogenous L. delbrueckii flora. When heat-treated yogurt was administered, L. delbrueckii was detected in all animals. S. thermophilus or L. delbrueckiisubsp. bulgaricus was not detected, indicating that heat-inactivated cells and their DNAs had already been digested and their own L. delbrueckii flora had been stimulated for growth.

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Poppi, Larissa B., Javier D. Rivaldi, Thais S. Coutinho, Claudete S. Astolfi-Ferreira, Antonio J. Piantino Ferreira, and Ismael M. Mancilha. "Effect of Lactobacillus sp. isolates supernatant on Escherichia coli O157:H7 enhances the role of organic acids production as a factor for pathogen control." Pesquisa Veterinária Brasileira 35, no. 4 (April 2015): 353–59. http://dx.doi.org/10.1590/s0100-736x2015000400007.

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Many attempts have been made to establish the control of foodborne pathogens through Lactobacillus isolates and their metabolism products with success being obtained in several situations. The aim of this study was to investigate the antagonistic effect of eight Lactobacillusisolates, including L. caseisubsp. pseudoplantarum,L. plantarum, L. reuteri and L. delbrueckii subsp. delbrueckii, on the pathogenic Escherichia colistrain O157:H7. The inhibitory effect of pure cultures and two pooled cultures supernatants of Lactobacillus on the growth of pathogenic bacteria was evaluated by the spot agar method and by monitoring turbidity. Antimicrobial activity was confirmed for L. reuteri and L. delbrueckii subsp. delbrueckii and for a pool of lactic acid bacteria. The neutralized supernatant of the pool exerted a higher antimicrobial activity than that of the individual strains. Furthermore, D-lactic acid and acetic acid were produced during growth of the Lactobacillus isolates studied.

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Petry, Sandrine, Sylviane Furlan, Marie-Jeanne Crepeau, Jutta Cerning, and Michel Desmazeaud. "Factors Affecting Exocellular Polysaccharide Production by Lactobacillus delbrueckii subsp.bulgaricus Grown in a Chemically Defined Medium." Applied and Environmental Microbiology 66, no. 8 (August 1, 2000): 3427–31. http://dx.doi.org/10.1128/aem.66.8.3427-3431.2000.

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ABSTRACT We developed a chemically defined medium (CDM) containing lactose or glucose as the carbon source that supports growth and exopolysaccharide (EPS) production of two strains ofLactobacillus delbrueckii subsp. bulgaricus. The factors found to affect EPS production in this medium were oxygen, pH, temperature, and medium constituents, such as orotic acid and the carbon source. EPS production was greatest during the stationary phase. Composition analysis of EPS isolated at different growth phases and produced under different fermentation conditions (varying carbon source or pH) revealed that the component sugars were the same. The EPS from strain L. delbrueckii subsp.bulgaricus CNRZ 1187 contained galactose and glucose, and that of strain L. delbrueckii subsp. bulgaricusCNRZ 416 contained galactose, glucose, and rhamnose. However, the relative proportions of the individual monosaccharides differed, suggesting that repeating unit structures can vary according to specific medium alterations. Under pH-controlled fermentation conditions, L. delbrueckii subsp. bulgaricusstrains produced as much EPS in the CDM as in milk. Furthermore, the relative proportions of individual monosaccharides of EPS produced in pH-controlled CDM or in milk were very similar. The CDM we developed may be a useful model and an alternative to milk in studies of EPS production.

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Gatti, Fornasari, and Neviani. "Differentiation of Lactobacillus delbrueckii subsp. bulgaricus and Lactobacillus delbrueckii subsp. lactis by SDS-PAGE of cell-wall proteins." Letters in Applied Microbiology 32, no. 5 (May 31, 2001): 352–56. http://dx.doi.org/10.1046/j.1472-765x.2001.00917.x.

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Tavşanlı, Hakan, Tülay Elal Mus, Figen Cetinkaya, Ergün Aynaoglu, and Recept Cibik. "Isolation of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus from nature: Technological characterisation and antibiotic resistance." Czech Journal of Food Sciences 39, No. 4 (August 29, 2021): 305–11. http://dx.doi.org/10.17221/296/2020-cjfs.

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Yoghurt fermenting bacteria were isolated from natural sources including plants, dew, and rain samples (total of 300 samples) by the same methods nomadic peoples used for several centuries in Turkey. Inoculation into the reconstituted skim milk followed by planting on specific media and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) analysis allowed for the identification of 18 Lactobacillus delbrueckii subsp. and 26 Streptococcus thermophilus. A multiplex polymerase chain reaction (PCR) assay applied to lactobacilli enabled the identification of 5 isolates as L. delbrueckii subsp. bulgaricus. The isolates showed a varying range of acidification rates and proteolytic activity in reconstituted skimmed milk (RSM). S. thermophilus isolates showed a broader range of resistance and the most frequent resistance was observed for streptomycin (69.2%), gentamycin (65.3%), clindamycin (61.5%), ampicillin (61.5%), kanamycin (53.8%), and erythromycin (50%). For L. delbrueckii subsp. the highest resistance was determined for vancomycin (38.8%), ciprofloxacin (33.3%), and penicillin (27.8%). The frequency of multiple resistance was tested on 14 different antimicrobials determining that 19 S. thermophilus (73%) and 3 L. delbrueckii subsp. (16.7%) demonstrated resistance to more than three different antibiotics. In contrast to this wide-ranging resistance, five isolates from each genus were found to be susceptible to all tested antibiotics. The present study indicates that lactic acid bacteria (LAB) isolated from nature may have broad-range of resistance to antibiotics and could be a source for the transfer of resistance.

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DE URRAZA, PATRICIO J., ANDREA GÓMEZ-ZAVAGLIA, MARIO E. LOZANO, VICTOR ROMANOWSKI, and GRACIELA L. DE ANTONI. "DNA fingerprinting of thermophilic lactic acid bacteria using repetitive sequence-based polymerase chain reaction." Journal of Dairy Research 67, no. 3 (August 2000): 381–92. http://dx.doi.org/10.1017/s002202990000426x.

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DNA fingerprints of lactic acid bacteria were generated by polymerase chain reaction using a primer based on the repetitive elements found in the genome of Streptococcus pneumoniae (BOX-PCR). The method made it possible to identify 37 isolates from raw milk, industrial starters and yogurt. Differentiation at species, subspecies and strain level was possible for Lactobacillus delbrueckii subsp. lactis, Lb. delbrueckii subsp bulgaricus and Str. thermophilus. BOX-PCR was also applied to studying the strain composition of a starter culture and the direct detection of strains in commercial fermented milk.

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., Kusmiati, Fifi Afiati, and Farha Elein Kukihi. "Exopolysaccharide (EPS) activity test of lactic acid bacteria (LAB) as immunomodulatory." Jurnal Ilmu Ternak dan Veteriner 21, no. 3 (September 26, 2017): 182. http://dx.doi.org/10.14334/jitv.v21i3.1414.

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<p>Immunomodulatory activity assay and characterization of exopolysaccharide (EPS) from Lactic Acid Bacteria (LAB) was done in Bogor. Bacteria used in this study was LAB strains of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus. Exopolysaccharide was extracted from L. delbrueckii subsp. bulgaricus and S. thermophilus then characterized with FT-IR spectrophotometer to determine the functional group. IR spectrum analysis using Fourier Transform-Infra Red (FT-IR) showed that EPS from both LAB isolates were carbohydrate compounds. Immunomodulatory activity in vivo from EPS was measured using phagocytic activity and phagocytic capacity macrophage cells from mice peritoneal cavity fluid. Exopolysaccharide were given orally to mice in concentrations of 100 μg/ml, 200 μg/ml and 300 μg/ml for 14 days then the mice were infected with Staphylococcus aureus. Result showed that EPS from both LAB isolate enhanced either phagocytic activity and phagocytic capacity macrophage cell from mice peritoneal fluid. EPS from L. delbrueckii subsp. bulgaricus concentration 300 μg/ml showed the highest phagocytic activity of macrophage cells and EPS from S. thermophilus concentration 300 μg/ml showed the highest phagocytic capacity. It is concluded that EPS potency tested as immunomodulatory derived from a culture of L. delbrueckii and S. thermophilus subsp.bulgaricus are able to increase the activity and phagocytosis murine peritoneal macrophages.</p>

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MEDINA, L. M., and R. JORDANO. "Survival of Constitutive Microflora in Commercially Fermented Milk Containing Bifidobacteria During Refrigerated Storage." Journal of Food Protection 57, no. 8 (August 1, 1994): 731–33. http://dx.doi.org/10.4315/0362-028x-57.8.731.

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The survival of constitutive microflora was studied in one batch (n = 50) of fermented milk containing bifidobacteria produced in Spain during storage at 7°C. Levels of Streptococcus salivarius subsp. thermophilus, Lactobacillus delbrueckii subsp. bulgaricus, and Bifidobacterium spp. and the pH of the product were determined on the day of collection and after 10, 17, 24, 28, 31, 36, 42, 51, and 84 d of storage. Initial populations of streptococci, lactobacilli, and bifidobacteria were 2.6 × 108, 5.1 × 107, and 7.4 × 106 CFU/g, respectively. The S. salivarius subsp. thermophilus population increased slightly after 10 d and then decreased during further refrigerated storage. Numbers of Bifidobacterium and L. delbrueckii subsp. bulgaricus decreased faster during storage. After 24 d (the reported shelf life of the product), levels of streptococci decreased only 10.7% as compared to decreases of 85.4 and 92.6% for lactobacilli and bifidobacteria, respectively. The pH values were between 4.57 and 3.81.

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Lee, Ju-Hoon, Jamie S. Halgerson, Jeong-Hwan Kim, and Daniel J. O'Sullivan. "Comparative Sequence Analysis of Plasmids from Lactobacillus delbrueckii and Construction of a Shuttle Cloning Vector." Applied and Environmental Microbiology 73, no. 14 (May 25, 2007): 4417–24. http://dx.doi.org/10.1128/aem.00099-07.

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ABSTRACT While plasmids are very commonly associated with the majority of the lactic acid bacteria, they are only very rarely associated with Lactobacillus delbrueckii, with only four characterized to date. In this study, the complete sequence of a native plasmid, pDOJ1, from a strain of Lactobacillus delbrueckii subsp. bulgaricus was determined. It consisted of a circular DNA molecule of 6,220 bp with a G+C content of 44.6% and a characteristic ori and encoded six open reading frames (ORFs), of which functions could be predicted for three—a mobilization (Mob) protein, a transposase, and a fused primase-helicase replication protein. Comparative analysis of pDOJ1 and the other available L. delbrueckii plasmids (pLBB1, pJBL2, pN42, and pLL1212) revealed a very similar organization and amino acid identities between 85 and 98% for the putative proteins of all six predicted ORFs from pDOJ1, reflecting a common origin for L. delbrueckii plasmids. Analysis of the fused primase-helicase replication gene found a similar fused organization only in the theta replicating group B plasmids from Streptococcus thermophilus. This observation and the ability of the replicon to function in S. thermophilus support the idea that the origin of plasmids in L. delbrueckii was likely from S. thermophilus. This may reflect the close association of these two species in dairy fermentations, particularly yogurt production. As no vector based on plasmid replicons from L. delbrueckii has previously been constructed, an Escherichia coli-L. delbrueckii shuttle cloning vector, pDOJ4, was constructed from pDOJ1, the p15A ori, the chloramphenicol resistance gene of pCI372, and the lacZ polylinker from pUC18. This cloning vector was successfully introduced into E. coli, L. delbrueckii subsp. bulgaricus, S. thermophilus, and Lactococcus lactis. This shuttle cloning vector provides a new tool for molecular analysis of Lactobacillus delbrueckii and other lactic acid bacteria.

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Zhang, Shuang, Lanwei Zhang, Lili Zhang, Zhen Feng, and Nditange Shigwedha. "Screening, purification, and characterization of proteinase from 3 Lactobacillus delbrueckii subsp. bulgaricus." RSC Advances 5, no. 114 (2015): 93733–38. http://dx.doi.org/10.1039/c5ra16767a.

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MANCA de NADRA, M. C., G. J. ANDUNI, and M. E. FARÍAS. "Influence of Artificial Sweeteners on the Kinetic and Metabolic Behavior of Lactobacillus delbrueckii subsp. bulgaricus." Journal of Food Protection 70, no. 10 (October 1, 2007): 2413–16. http://dx.doi.org/10.4315/0362-028x-70.10.2413.

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The addition of artificial sweeteners to a LAPT (yeast extract, peptone, and tryptone) medium without supplemented sugar increased the growth rate and final biomass of Lactobacillus delbrueckii subsp. bulgaricus YOP 12 isolated from commercial yogurt. Saccharin and cyclamate were consumed during microorganism growth, while the uptake of aspartame began once the medium was glucose depleted. The pH of the media increased as a consequence of the ammonia released into the media supplemented with the sweeteners. The L. delbrueckii subsp. bulgaricus strain was able to grow in the presence of saccharin, cyclamate, or aspartame, and at low sweetener concentrations, the microorganism could utilize cyclamate and aspartame as an energy and carbon source.

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32

Räisänen, Liisa, Karin Schubert, Tiina Jaakonsaari, and Tapani Alatossava. "Characterization of Lipoteichoic Acids as Lactobacillus delbrueckii Phage Receptor Components." Journal of Bacteriology 186, no. 16 (August 15, 2004): 5529–32. http://dx.doi.org/10.1128/jb.186.16.5529-5532.2004.

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ABSTRACT Lipoteichoic acids (LTAs) were purified from Lactobacillus delbrueckii subsp. lactis ATCC 15808 and its LL-H adsorption-resistant mutant, Ads-5, by hydrophobic interaction chromatography. L. delbrueckii phages (LL-H, the LL-H host range mutant, and JCL1032) were inactivated by these poly(glycerophosphate) type of LTAs in vitro in accordance to their adsorption to intact ATCC 15808 and Ads-5 cells.

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Do Carmo, A., D. da Silva, M. De Oliveira, A. Borges, A. De Carvalho, and C. De Moraes. "Genes involved in protein metabolism of the probiotic lactic acid bacterium Lactobacillus delbrueckii UFV H2b20." Beneficial Microbes 2, no. 3 (September 1, 2011): 209–20. http://dx.doi.org/10.3920/bm2011.0025.

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A basic requirement for the prediction of the potential use of lactic acid bacteria (LAB) in the dairy industry is the identification of specific genes involved in flavour-forming pathways. The probiotic Lactobacillus delbrueckii UFV H2b20 was submitted to a genetic characterisation and phylogenetic analysis of genes involved in protein catabolism. Eight genes belonging to this system were identified, which possess a closely phylogenetic relationship to NCFM strains representative, as it was demonstrated for oppC and oppBII, encoding oligopeptide transport system components. PepC, PepN, and PepX might be essential for growth of LAB, probiotic or not, since the correspondent genes are always present, including in L. delbrueckii UFV H2b20 genome. For pepX gene, a probable link between carbohydrate catabolism and PepX expression may exists, where it is regulated by PepR1/CcpA-like, a common feature between Lactobacillus strains and also in L. delbrueckii UFV H2b20. The well conserved evolutionary history of the ilvE gene is evidence that the pathways leading to branched-chain amino acid degradation, such as isoleucine and valine, are similar among L. delbrueckii subsp. bulgaricus strains and L. delbrueckii UFV H2b20. Thus, the involvement of succinate in flavour formation can be attributed to IlvE activity. The presence of aminopeptidase G in L. delbrueckii UFV H2b20 genome, which is absent in several strains, might improve the proteolytic activity and effectiveness. The nucleotide sequence encoding PepG revealed that it is a cysteine endopeptidase, belonging to Peptidase C1 superfamily; sequence analysis showed 99% identity with L. delbrueckii subsp. bulgaricus ATCC 11842 pepG, whereas protein sequence analysis revealed 100% similarity with PepG from the same organism. The present study proposes a schematic model to explain how the proteolytic system of the probiotic L. delbrueckii UFV H2b20 works, based on the components identified so far.

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Mogna, Luca, Francesca Deidda, Stefania Nicola, Angela Amoruso, Mario Del Piano, and Giovanni Mogna. "In Vitro Inhibition of Klebsiella pneumoniae by Lactobacillus delbrueckii Subsp. delbrueckii LDD01 (DSM 22106)." Journal of Clinical Gastroenterology 50 (2016): S136—S139. http://dx.doi.org/10.1097/mcg.0000000000000680.

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Elean, M., L. Albarracín, P. G. Cataldo, A. Londero, H. Kitazawa, L. Saavedra, J. Villena, and E. M. Hebert. "New immunobiotics from highly proteolytic Lactobacillus delbrueckii strains: their impact on intestinal antiviral innate immune response." Beneficial Microbes 11, no. 4 (August 12, 2020): 375–90. http://dx.doi.org/10.3920/bm2019.0198.

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Proteolytic starter cultures with intrinsic immunomodulatory activities are desirably features for the development of functional foods, which would significantly reduce the cost of their production (one-strain starter) having an additional beneficial effect on the host. In this work, Lactobacillus delbrueckii strains were selected according to their ability to efficiently hydrolyse β-casein and to modulate the immune system. Among 36 strains evaluated, the highest proteolytic activities were found for L. delbrueckii subsp. lactis CRL581 and L. delbrueckii subsp. bulgaricus CRL656. The immunomodulatory effect of both strains and their β-casein hydrolysates (CRL581 and CRL656 hydrolysates, respectively) were studied in a murine model. Balb/c mice were fed lactobacilli or their hydrolysates for three days. One day after the last lactobacilli or hydrolysate treatments, mice were challenged with the Toll-like receptor 3 (TLR3) agonist poly(I:C) by intraperitoneal injection. Before and after poly(I:C) challenge the phagocytic and microbicidal activity of peritoneal macrophages, intestinal immunoglobulin A (IgA), cytokine profile, and histological analysis of the intestine were analysed. L. delbrueckii subsp. lactis CRL581 significantly increased the activation of peritoneal macrophages as well as the levels of intestinal IgA, interleukin (IL)-10 and interferon (IFN)-γ when compared to untreated controls. In addition, the CRL581 strain was able to significantly reduce the intestinal inflammatory damage triggered by TLR3 activation. L. delbrueckii CRL581 increased the levels of IL-10, IFN-γ and IFN-β, and reduced tumour necrosis factor alpha and IL-6 concentrations in the intestine of poly(I:C)-challenged mice. No immunomodulatory effects were observed for the CRL656 strain or for the CRL581 or CRL656 hydrolysates. The results of this work show that the technologically relevant and high proteolytic strain L. delbrueckii CRL581 is able to beneficially modulate the intestinal innate antiviral immune response. Although further studies with the CRL581 strain are required to corroborate and deepen its immunological effects, this bacterium is an interesting alternative for the development of new functional foods with antiviral capabilities.

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Tsakalidou, E., R. Anastasiou, I. Vandenberghe, J. van Beeumen, and G. Kalantzopoulos. "Cell-Wall-Bound Proteinase of Lactobacillus delbrueckii subsp. lactis ACA-DC 178: Characterization and Specificity for β-Casein." Applied and Environmental Microbiology 65, no. 5 (May 1, 1999): 2035–40. http://dx.doi.org/10.1128/aem.65.5.2035-2040.1999.

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ABSTRACT Lactobacillus delbrueckii subsp. lactisACA-DC 178, which was isolated from Greek Kasseri cheese, produces a cell-wall-bound proteinase. The proteinase was removed from the cell envelope by washing the cells with a Ca2+-free buffer. The crude proteinase extract shows its highest activity at pH 6.0 and 40°C. It is inhibited by phenylmethylsulfonyl fluoride, showing that the enzyme is a serine-type proteinase. Considering the substrate specificity, the enzyme is similar to the lactococcal PI-type proteinases, since it hydrolyzes β-casein mainly and α- and κ-caseins to a much lesser extent. The cell-wall-bound proteinase from L. delbrueckii subsp. lactisACA-DC 178 liberates four main peptides from β-casein, which have been identified.

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GIRAFFA, GIORGIO, ERASMO NEVIANI, and ADELIA VENERONI. "Use of Conductance to Detect Bacteriocin Activity." Journal of Food Protection 53, no. 9 (September 1, 1990): 772–76. http://dx.doi.org/10.4315/0362-028x-53.9.772.

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The inhibitory activity of a bacteriocin produced by Lactobacillus delbrueckii subsp. lactis G4 (Bac+) in milk was investigated by using conductivity measurements. The bacteriocin showed an inhibitory action toward some strains belonging to L. delbrueckii subsp. bulgaricus species. A delay in detection time (δDT) of two milk cultures sensitive to bacteriocin, grown in the presence of preformed bacteriocin, was observed. An inactivation as well as a modified growth rate of the sensitive cultures due to bacteriocin activity might explain the δDT, as indicated by longer generation time (tg). Cells showed the highest sensitivity to bacteriocin during the log phase of growth that corresponded to the beginning of the acceleration of the conductance curve (DT).

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HARP, E., and S. E. GILLILAND. "Evaluation of a Select Strain of Lactobacillus delbrueckii subsp. lactis as a Biological Control Agent for Pathogens on Fresh-Cut Vegetables Stored at 7° C." Journal of Food Protection 66, no. 6 (June 1, 2003): 1013–18. http://dx.doi.org/10.4315/0362-028x-66.6.1013.

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Raw vegetables inoculated with selected pathogenic bacteria were treated with a strain of Lactobacillus delbrueckii subsp. lactis, which was selected for its ability to produce hydrogen peroxide at refrigerated temperatures. The vegetables inoculated included broccoli, cabbage, carrots, and lettuce. Each vegetable was rinsed, chopped, and stored under conditions similar to those used for ready-to-eat vegetables sold at retail. Portions of each vegetable were separately inoculated with one of two pathogenic bacteria, Escherichia coli O157:H7 or Listeria monocytogenes. Prior to packaging, one portion of each inoculated vegetable was treated with a cell suspension of the selected strain of L. delbrueckii subsp. lactis. The vegetables were stored at 7°C for 6 days. The populations of pathogens and lactobacilli on each sample were enumerated on storage days 0, 3, and 6. Although populations of L. delbrueckii subsp. lactis remained at high levels during storage, there was no noticeable antagonistic action against the pathogens under conditions similar to those used for these products at the retail level. Each pathogen survived on all vegetables throughout storage. Further testing revealed that there was apparently sufficient catalase activity in the cut vegetables to destroy enough of the hydrogen peroxide to prevent antagonistic action against the pathogens.

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Dekumpitiya, N., D. Gamlakshe, S. I. Abeygunawardena, and D. Jayaratne. "Identification of the Microbial Consortium in Sri Lankan Buffalo Milk Curd and their growth in the Presence of Prebiotics." Journal of Food Science and Technology Nepal 9 (April 8, 2016): 20–30. http://dx.doi.org/10.3126/jfstn.v9i0.12579.

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The production and consumption of traditionally fermented buffalo milk curd provides many economical and food security benefits to both producers and consumers in the country. To improve this traditional product as a value-added product, an investigation was conducted to elucidate the microbial consortium associated with curd using culturable techniques and the microbial load was quantified in the presence of prebiotics. Twenty six samples of curd were analyzed to isolate microorganisms. The two major LAB groups present in the samples were characterized as Lactobacillus and Streptococcus. LABs were further identified as Lactobacillus delbrueckii subsp. lactis, L. planatarum, L. helviticus, Lactobacillus delbrueckii subsp. bulgaricus and L. casei subsp casei, Streptococcus thermophiles and S. lactis. Saccharomyces cerevisiae, Micrococcus spp., and Bacillus spp. were also present in this microbial consortium The addition of two types of commercially available prebiotics improved the counts of Lactobacillus in curd samples, despite the difference in the prebiotic compounds.

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Fang, Xiang, Yanlin Li, Wei Guo, Wencan Ke, Sisi Bi, Xusheng Guo, and Ying Zhang. "Lactobacillus delbrueckii subsp. bulgaricus F17 and Leuconostoc lactis H52 supernatants delay the decay of strawberry fruits: a microbiome perspective." Food & Function 10, no. 12 (2019): 7767–81. http://dx.doi.org/10.1039/c9fo02079a.

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Lactobacillus delbrueckii subsp. bulgaricus F17 and Leuconostoc lactis H52 as the potential biopreservative, which delayed the decay and changed the structure of microbial community of the ‘Benihoppe’ strawberry fruits.

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SENNE, M. M., and S. E. GILLILAND. "Antagonistic Action of Cells of Lactobacillus delbrueckii subsp. lactis against Pathogenic and Spoilage Microorganisms in Fresh Meat Systems†." Journal of Food Protection 66, no. 3 (March 1, 2003): 418–25. http://dx.doi.org/10.4315/0362-028x-66.3.418.

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Cells of Lactobacillus delbrueckii subsp. lactis RM2-5 were added to various meat model systems that had been inoculated with Escherichia coli O157:H7 or Salmonella Typhimurium to determine whether these lactobacilli were antagonistic to the pathogens during storage at 5°C. Experiments in which L. delbrueckii subsp. lactis RM2-5 was directly applied to the surfaces of beefsteaks resulted in significant (P < 0.05) reductions in the growth of psychrotrophs and coliforms plus a slight decrease in the numbers of E. coli O157:H7 over time relative to those for control samples to which no lactobacilli had been added. Experiments involving the direct application of L. delbrueckii subsp. lactis RM2-5 to the surfaces of freshly slaughtered beef and pork carcass samples inoculated with either E. coli O157:H7 or Salmonella Typhimurium showed significant (P < 0.05) declines in numbers of the pathogens as well as a reduction in the growth of psychrotrophs during storage at 5°C for 6 days. The results of the experiments suggest that lactobacillus cultures have potential for use in an intervention technology for the control of foodborne pathogens, especially on the surfaces of beef and pork carcasses. The results of this study also suggest that an extension of the shelf life of meat can result from the decreased growth of psychrotrophic spoilage organisms.

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Henri-Dubernet, Ségolène, Nathalie Desmasures, and Micheline Guéguen. "Diversity and dynamics of lactobacilli populations during ripening of RDO Camembert cheese." Canadian Journal of Microbiology 54, no. 3 (March 2008): 218–28. http://dx.doi.org/10.1139/w07-137.

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The diversity and dynamics of Lactobacillus populations in traditional raw milk Camembert cheese were monitored throughout the manufacturing process in 3 dairies. Culture-dependent analysis was carried out on isolates grown on acidified de Man – Rogosa – Sharpe agar and Lactobacillus anaerobic de Man Rogosa Sharpe agar supplemented with vancomycin and bromocresol green media. The isolates were identified by polymerase chain reaction – temperature gradient gel electrophoresis (PCR–TGGE) and (or) species-specific PCR and (or) sequencing, and Lactobacillus paracasei and Lactobacillus plantarum isolates were characterized by pulsed field gel electrophoresis (PFGE). Milk and cheese were subjected to culture-independent analysis by PCR–TGGE. Presumed lactobacilli were detected by plate counts throughout the ripening process. However, molecular analysis of total DNA and DNA of isolates failed to detect Lactobacillus spp. in certain cases. The dominant species in the 3 dairies was L. paracasei. PFGE analysis revealed 21 different profiles among 39 L. paracasei isolates. Lactobacillus plantarum was the second most isolated species, but it occurred nearly exclusively in one dairy. The other species isolated were Lactobacillus parabuchneri , Lactobacillus fermentum , Lactobacillus acidophilus , Lactobacillus helveticus , a Lactobacillus psittaci/delbrueckii subsp. bulgaricus/gallinarum/crispatus group, Lactobacillus rhamnosus , Lactobacillus delbrueckii subsp. bulgaricus, L. delbrueckii subsp. lactis, Lactobacillus brevis , Lactobacillus kefiri , and Lactobacillus perolens. Lactobacilli diversity at the strain level was high. Dynamics varied among dairies, and each cheese exhibited a specific picture of species and strains.

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Burns, Patricia, Gabriel Vinderola, Jorge Reinheimer, Isabel Cuesta, Clara G. de los Reyes-Gavilán, and Patricia Ruas-Madiedo. "Technological characterization and survival of the exopolysaccharide-producing strain Lactobacillus delbrueckii subsp. lactis 193 and its bile-resistant derivative 193+ in simulated gastric and intestinal juices." Journal of Dairy Research 78, no. 3 (July 21, 2011): 357–64. http://dx.doi.org/10.1017/s0022029911000355.

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The capacity of lactic acid bacteria to produce exopolysaccharides (EPS) conferring microorganisms a ropy phenotype could be an interesting feature from a technological point of view. Progressive adaptation to bile salts might render some lactobacilli able to overcome physiological gut barriers but could also modify functional properties of the strain, including the production of EPS. In this work some technological properties and the survival ability in simulated gastrointestinal conditions of Lactobacillus delbrueckii subsp. lactis 193, and Lb. delbrueckii subsp. lactis 193+, a strain with stable bile-resistant phenotype derived thereof, were characterized in milk in order to know whether the acquisition of resistance to bile could modify some characteristics of the microorganism. Both strains were able to grow and acidify milk similarly; however the production of ethanol increased at the expense of the aroma compound acetaldehyde in milk fermented by the strain 193+, with respect to milk fermented by the strain 193. Both microorganisms produced a heteropolysaccharide composed of glucose and galactose, and were able to increase the viscosity of fermented milks. In spite of the higher production yield of EPS by the bile-resistant strain 193+, it displayed a lower ability to increase viscosity than Lb. delbrueckii subsp. lactis 193. Milk increased survival in simulated gastric juice; the presence of bile improved adhesion to the intestinal cell line HT29-MTX in both strains. However, the acquisition of a stable resistance phenotype did not improve survival in simulated gastric and intestinal conditions or the adhesion to the intestinal cell line HT29-MTX. Thus, Lb. delbrueckii subsp. lactis 193 presents suitable technological properties for the manufacture of fermented dairy products; the acquisition of a stable bile-resistant phenotype modified some properties of the microorganism. This suggests that the possible use of bile-resistant derivative strains should be carefully evaluated in each specific application considering the influence that the acquisition of a stable bile-resistant phenotype could have in survival ability in gastric and intestinal conditions and in technological properties.

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Casey, Eoghan, Jennifer Mahony, Mary O'Connell-Motherway, Francesca Bottacini, Anneleen Cornelissen, Horst Neve, Knut J. Heller, Jean-Paul Noben, Fabio Dal Bello, and Douwe van Sinderen. "Molecular Characterization of Three Lactobacillus delbrueckii subsp. bulgaricus Phages." Applied and Environmental Microbiology 80, no. 18 (July 7, 2014): 5623–35. http://dx.doi.org/10.1128/aem.01268-14.

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ABSTRACTIn this study, three phages infectingLactobacillus delbrueckiisubsp.bulgaricus, named Ld3, Ld17, and Ld25A, were isolated from whey samples obtained from various industrial fermentations. These phages were further characterized in a multifaceted approach: (i) biological and physical characterization through host range analysis and electron microscopy; (ii) genetic assessment through genome analysis; (iii) mass spectrometry analysis of the structural components of the phages; and (iv), for one phage, transcriptional analysis by Northern hybridization, reverse transcription-PCR, and primer extension. The three obtained phage genomes display high levels of sequence identity to each other and to genomes of the so-called group bL. delbrueckiiphages c5, LL-Ku, and phiLdb, where some of the observed differences are believed to be responsible for host range variations.

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Toba, Takahiro, Emiko Yoshioka, and Takatoshi Itoh. "Lacticin, a bacteriocin produced by Lactobacillus delbrueckii subsp. lactis." Letters in Applied Microbiology 12, no. 2 (February 1991): 43–45. http://dx.doi.org/10.1111/j.1472-765x.1991.tb00499.x.

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Streit, Fernanda, Georges Corrieu, and Catherine Béal. "Acidification improves cryotolerance of Lactobacillus delbrueckii subsp. bulgaricus CFL1." Journal of Biotechnology 128, no. 3 (February 20, 2007): 659–67. http://dx.doi.org/10.1016/j.jbiotec.2006.11.012.

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Delley, Michèle, and Jacques-Edouard Germond. "Differentiation of Lactobacillus helveticus, Lactobacillus delbrueckii subsp bulgaricus, subsp lactis and subsp delbrueckii Using Physiological and Genetic Tools and Reclassification of some Strains from the ATCC Collection." Systematic and Applied Microbiology 25, no. 2 (January 2002): 228–31. http://dx.doi.org/10.1078/0723-2020-00106.

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Grobben, G. J., I. Chin-Joe, V. A. Kitzen, I. C. Boels, F. Boer, J. Sikkema, M. R. Smith, and J. A. M. de Bont. "Enhancement of Exopolysaccharide Production byLactobacillus delbrueckii subsp. bulgaricus NCFB 2772 with a Simplified Defined Medium." Applied and Environmental Microbiology 64, no. 4 (April 1, 1998): 1333–37. http://dx.doi.org/10.1128/aem.64.4.1333-1337.1998.

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ABSTRACT The aim of this work was to investigate the medium requirements for growth and production of exopolysaccharides by Lactobacillus delbrueckii subsp. bulgaricus NCFB 2772. The strain was grown in batch cultures on a chemically defined medium, and the technique of single omission of medium components was applied to determine the nutritional requirements. The omission of aspartic acid, glutamic acid, or glycine affected growth only slightly, and the omission of glutamine, asparagine, or threonine resulted in a stronger reduction of the growth. All the other amino acids were essential. Multiple omissions of amino acids caused an almost complete loss of growth. L. delbrueckii subsp. bulgaricusrequired only riboflavin, calcium pantothenate, and nicotinic acid as individual vitamins. Surprisingly, when only these vitamins were present in the medium and other vitamins were not, less growth was observed than in the complete medium but the amount of exopolysaccharide produced was significantly greater. These observations were studied in more detail with a simplified defined medium in which L. delbrueckii subsp.bulgaricus was able to grow and produce exopolysaccharides. Although the final optical density in the simplified medium was lower, the production of exopolysaccharides was about twofold higher than in the complete medium.

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Ragoubi, Chaima, Laura Quintieri, Donato Greco, Amel Mehrez, Imed Maatouk, Vito D’Ascanio, Ahmed Landoulsi, and Giuseppina Avantaggiato. "Mycotoxin Removal by Lactobacillus spp. and Their Application in Animal Liquid Feed." Toxins 13, no. 3 (March 2, 2021): 185. http://dx.doi.org/10.3390/toxins13030185.

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The removal of mycotoxins from contaminated feed using lactic acid bacteria (LAB) has been proposed as an inexpensive, safe, and promising mycotoxin decontamination strategy. In this study, viable and heat-inactivated L. acidophilus CIP 76.13T and L. delbrueckii subsp. bulgaricus CIP 101027T cells were investigated for their ability to remove aflatoxin B1 (AFB1), ochratoxin A (OTA), zearalenone (ZEA), and deoxynivalenol (DON) from MRS medium and PBS buffer over a 24 h period at 37 °C. LAB decontamination activity was also assessed in a ZEA-contaminated liquid feed (LF). Residual mycotoxin concentrations were determined by UHPLC-FLD/DAD analysis. In PBS, viable L. acidophilus CIP 76.13T and L. delbrueckii subsp. bulgaricus CIP 101027T cells removed up to 57% and 30% of ZEA and DON, respectively, while AFB1 and OTA reductions were lower than 15%. In MRS, 28% and 33% of ZEA and AFB1 were removed, respectively; OTA and DON reductions were small (≤15%). Regardless of the medium, heat-inactivated cells produced significantly lower mycotoxin reductions than those obtained with viable cells. An adsorption mechanism was suggested to explain the reductions in AFB1 and OTA, while biodegradation could be responsible for the removal of ZEA and DON. Both viable LAB strains reduced ZEA by 23% in contaminated LF after 48 h of incubation. These findings suggest that LAB strains of L. acidophilus CIP 76.13T and L. delbrueckii subsp. bulgaricus CIP 101027T may be applied in the feed industry to reduce mycotoxin contamination.

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Sawatari, Yuki, and Atsushi Yokota. "Diversity and Mechanisms of Alkali Tolerance in Lactobacilli." Applied and Environmental Microbiology 73, no. 12 (April 20, 2007): 3909–15. http://dx.doi.org/10.1128/aem.02834-06.

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ABSTRACT We determined the maximum pH that allows growth (pHmax) for 34 strains of lactobacilli. High alkali tolerance was exhibited by strains of Lactobacillus casei, L. paracasei subsp. tolerans, L. paracasei subsp. paracasei, L. curvatus, L. pentosus, and L. plantarum that originated from plant material, with pHmax values between 8.5 and 8.9. Among these, L. casei NRIC 1917 and L. paracasei subsp. tolerans NRIC 1940 showed the highest pHmax, at 8.9. Digestive tract isolates of L. gasseri, L. johnsonii, L. reuteri, L. salivarius subsp. salicinius, and L. salivarius subsp. salivarius exhibited moderate alkali tolerance, with pHmax values between 8.1 and 8.5. Dairy isolates of L. delbrueckii subsp. bulgaricus, L. delbrueckii subsp. lactis, and L. helveticus exhibited no alkali tolerance, with pHmax values between 6.7 and 7.1. Measurement of the internal pH of representative strains revealed the formation of transmembrane proton gradients (ΔpH) in a reversed direction (i.e., acidic interior) at alkaline external-pH ranges, regardless of their degrees of alkali tolerance. Thus, the reversed ΔpH did not determine alkali tolerance diversity. However, the ΔpH contributed to alkali tolerance, as the pHmax values of several strains decreased with the addition of nigericin, which dissipates ΔpH. Although neutral external-pH values resulted in the highest glycolysis activity in the presence of nigericin regardless of alkali tolerance, substantial glucose utilization was still detected in the alkali-tolerant strains, even in a pH range of between 8.0 and 8.5, at which the remaining strains lost most activity. Therefore, the alkali tolerance of glycolysis reactions contributes greatly to the determination of alkali tolerance diversity.

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Journal articles on the topic 'Delbrueckii subsp'

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