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Journal articles on the topic 'Cellobiosio'

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Published: 9 March 2023
Last updated: 10 March 2023

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1

Best, Wayne M., Robert V. Stick, and D. Matthew G. Tilbrook. "The Synthesis of Some Epoxyalkyl Deoxyhalo-β-cellobiosides." Australian Journal of Chemistry 50, no. 1 (1997): 13. http://dx.doi.org/10.1071/c96078.

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2,3-Epoxypropyl and 3,4-epoxybutyl 6′-deoxy-6′-iodo-β-cellobioside, together with 3,4-epoxybutyl 6′- deoxy-6′-fluoro-β-cellobioside, were prepared as putative inhibitors and reporter groups for events occurring at the active site of some β-glucan hydrolases. As well, related syntheses gave the previously unknown 6-deoxy-6-fluoro- and 6′-deoxy-6′-fluoro-cellobioses.
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2

Rodriguez, EB, and RV Stick. "The Synthesis of Active-Site Directed Inhibitors of Some β-Glucan Hydrolases." Australian Journal of Chemistry 43, no. 4 (1990): 665. http://dx.doi.org/10.1071/ch9900665.

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The 2,3-epoxypropyl, 3,4-epoxybutyl and 4,5-epoxypentyl β-glycosides of D-glucose, cellobiose and laminaribiose have been prepared. As well, the 4,5-epoxypentyl β-glycosides of cellotriose, laminaritriose and two other trisaccharides have been synthesized. 3,4-Epoxybutyl β-cellobioside has also been prepared with a 14C-label in the cellobiose residue.
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3

BECKER, Dieter, Karin S. H. JOHNSON, Anu KOIVULA, Martin SCHÜLEIN, and Michael L. SINNOTT. "Hydrolyses of α- and β-cellobiosyl fluorides by Cel6A (cellobiohydrolase II) of Trichoderma reesei and Humicola insolens." Biochemical Journal 345, no. 2 (January 10, 2000): 315–19. http://dx.doi.org/10.1042/bj3450315.

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We have measured the hydrolyses of α- and β-cellobiosyl fluorides by the Cel6A [cellobiohydrolase II (CBHII)] enzymes of Humicola insolens and Trichoderma reesei, which have essentially identical crystal structures [Varrot, Hastrup, Schülein and Davies (1999) Biochem. J. 337, 297-304]. The β-fluoride is hydrolysed according to Michaelis-Menten kinetics by both enzymes. When the ~ 2.0% of β-fluoride which is an inevitable contaminant in all preparations of the α-fluoride is hydrolysed by Cel7A (CBHI) of T. reesei before initial-rate measurements are made, both Cel6A enzymes show a sigmoidal dependence of rate on substrate concentration, as well as activation by cellobiose. These kinetics are consistent with the classic Hehre resynthesis-hydrolysis mechanism for glycosidase-catalysed hydrolysis of the ‘wrong’ glycosyl fluoride for both enzymes. The Michaelis-Menten kinetics of α-cellobiosyl fluoride hydrolysis by the T. reesei enzyme, and its inhibition by cellobiose, previously reported [Konstantinidis, Marsden and Sinnott (1993) Biochem. J. 291, 883-888] are withdrawn. 1H NMR monitoring of the hydrolysis of α-cellobiosyl fluoride by both enzymes reveals that in neither case is α-cellobiosyl fluoride released into solution in detectable quantities, but instead it appears to be hydrolysed in the enzyme active site as soon as it is formed.
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4

Konstantinidis, A. K., I. Marsden, and M. L. Sinnott. "Hydrolyses of α- and β-cellobiosyl fluorides by cellobiohydrolases of Trichoderma reesei." Biochemical Journal 291, no. 3 (May 1, 1993): 883–88. http://dx.doi.org/10.1042/bj2910883.

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Cellobiohydrolase II hydrolyses alpha- and beta-D-cellobiosyl fluorides to alpha-cellobiose at comparable rates, according to Michaelis-Menten kinetics. The stereochemistry, absence of transfer products and strict hyperbolic kinetics of the hydrolysis of alpha-cellobiosyl fluoride suggest that the mechanism for the alpha-fluoride may be the enzymic counterpart of the SNi reaction observed in the trifluoroethanolysis of alpha-glucopyranosyl fluoride [Sinnott and Jencks (1980) J. Am. Chem. Soc. 102, 2026-2032]. The absolute factors by which this enzyme accelerates fluoride ion release are small and greater for the alpha-fluoride than for the beta, suggesting that its biological function may not be just glycoside hydrolysis. Cellobiohydrolase I hydrolyses only beta-cellobiosyl fluoride, which is, however, an approx. 1-3% contaminant in alpha-cellobiosyl fluoride as prepared and purified by conventional methods. Instrumental assays for the various components of the cellulase complex are discussed.
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5

Hildebrand, Amanda, J. Bennett Addison, Takao Kasuga, and Zhiliang Fan. "Cellobionic acid inhibition of cellobiohydrolase I and cellobiose dehydrogenase." Biochemical Engineering Journal 109 (May 2016): 236–42. http://dx.doi.org/10.1016/j.bej.2016.01.024.

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6

Reverbel-Leroy, Corinne, Goetz Parsiegla, Vincent Moreau, Michel Juy, Chantal Tardif, Hugues Driguez, Jean-Pierre Bélaich, and Richard Haser. "Crystallization of the catalytic domain of Clostridium cellulolyticum CeIF cellulase in the presence of a newly synthesized cellulase inhibitor." Acta Crystallographica Section D Biological Crystallography 54, no. 1 (January 1, 1998): 114–18. http://dx.doi.org/10.1107/s090744499700797x.

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The catalytic domain of the CeIF processive endocellulase, a family 48 glycosyl hydrolase from Clostridium cellulolyticum has been crystallized in the presence of a newly synthesized inhibitor (methyl 4-S-β-cellobiosyl-4-thio-β-cellobioside), by vapour diffusion, using PEG as a precipitant. The protein crystallizes in the orthorhombic P212121 space group and diffracts to a resolution of 2.0 Å. The unit-cell parameters are a = 61.4, b = 84.5, c = 121.9 Å.
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7

Oh, Yu-Ri, and Gyeong Tae Eom. "Efficient production of cellobionic acid from cellobiose by genetically modified Pseudomonas taetrolens." Biochemical Engineering Journal 178 (January 2022): 108282. http://dx.doi.org/10.1016/j.bej.2021.108282.

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8

Bok, Jin-Duck, Dinesh A. Yernool, and Douglas E. Eveleigh. "Purification, Characterization, and Molecular Analysis of Thermostable Cellulases CelA and CelB fromThermotoga neapolitana." Applied and Environmental Microbiology 64, no. 12 (December 1, 1998): 4774–81. http://dx.doi.org/10.1128/aem.64.12.4774-4781.1998.

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ABSTRACT Two thermostable endocellulases, CelA and CelB, were purified fromThermotoga neapolitana. CelA (molecular mass, 29 kDa; pI 4.6) is optimally active at pH 6.0 at 95°C, while CelB (molecular mass, 30 kDa; pI 4.1) has a broader optimal pH range (pH 6.0 to 6.6) at 106°C. Both enzymes are characterized by a high level of activity (high V max value and low apparentKm value) with carboxymethyl cellulose; the specific activities of CelA and CelB are 1,219 and 1,536 U/mg, respectively. With p-nitrophenyl cellobioside theV max values of CelA and CelB are 69.2 and 18.4 U/mg, respectively, while the Km values are 0.97 and 0.3 mM, respectively. The major end products of cellulose hydrolysis, glucose and cellobiose, competitively inhibit CelA, and CelB. The Ki values for CelA are 0.44 M for glucose and 2.5 mM for cellobiose; the Ki values for CelB are 0.2 M for glucose and 1.16 mM for cellobiose. CelB preferentially cleaves larger cellooligomers, producing cellobiose as the end product; it also exhibits significant transglycosylation activity. This enzyme is highly thermostable and has half-lives of 130 min at 106°C and 26 min at 110°C. A single clone encoding thecelA and celB genes was identified by screening a T. neapolitana genomic library in Escherichia coli. The celA gene encodes a 257-amino-acid protein, while celB encodes a 274-amino-acid protein. Both proteins belong to family 12 of the glycosyl hydrolases, and the two proteins are 60% similar to each other. Northern blots of T. neapolitana mRNA revealed that celA andcelB are monocistronic messages, and both genes are inducible by cellobiose and are repressed by glucose.
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9

Zhang, Yiyi, Yi Li, Shizuo Li, Hanbo Zheng, and Jiefeng Liu. "A Molecular Dynamics Study of the Generation of Ethanol for Insulating Paper Pyrolysis." Energies 13, no. 1 (January 5, 2020): 265. http://dx.doi.org/10.3390/en13010265.

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Cellulosic insulation paper is usually used in oil-immersed transformer insulation systems. In this study, the molecular dynamics method based on reaction force field (ReaxFF) was used to simulate the pyrolysis process of a cellobiose molecular model. Through a series of ReaxFF- Molecular Dynamics (MD) simulations, the generation path of ethanol at the atomic level was studied. Because the molecular system has hydrogen bonding, force-bias Monte Carlo (fbMC) is mixed into ReaxFF to reduce the cost of calculation by reducing the sampled data. In order to ensure the reliability of the simulation, a model composed of 20 cellobioses and a model composed of 40 cellobioses were respectively established for repeated simulation in the range of 500–3000 K. The results show that insulating paper produced ethanol at extreme thermal fault, and the intermediate product of vinyl alcohol is the key to the aging process. It is also basically consistent with others’ previous experiment results. So it can provide an effective reference for the use of ethanol as an indicator to evaluate the aging condition of transformers.
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10

ZECHEL, David L., Shouming HE, Claude DUPONT, and Stephen G. WITHERS. "Identification of Glu-120 as the catalytic nucleophile in Streptomyces lividans endoglucanase CelB." Biochemical Journal 336, no. 1 (November 15, 1998): 139–45. http://dx.doi.org/10.1042/bj3360139.

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Streptomyces lividans CelB is a family-12 endoglucanase that hydrolyses cellulose with retention of anomeric configuration. A recent X-ray structure of the catalytic domain at 1.75 Å resolution has led to the preliminary assignment of Glu-120 and Glu-203 as the catalytic nucleophile and general acid–base respectively [Sulzenbacher, Shareck, Morosoli, Dupont and Davies (1997) Biochemistry 36, 16032–16039]. The present study confirms the identity of the nucleophile by trapping the glycosyl-enzyme intermediate with the mechanism-based inactivator 2´,4´-dinitrophenyl 2-deoxy-2-fluoro-β-d-cellobioside (2FDNPC). The kinetics of inactivation proceeded in a saturable fashion, yielding the parameters kinact = 0.29±0.02 min-1 and Kinact = 0.72±0.08 mM. Uncompetitive inhibition was observed at high concentrations of 2FDNPC (Ki = 9±1 mM), a behaviour that was also observed with the substrate 2´,4´-dinitrophenyl β-d-cellobioside (kcat = 40±1 s-1, Km = 0.35±0.03 mM, Ki = 24±4 mM). Protection against inactivation was afforded by the competitive inhibitor cellobiose. The electrospray ionization (ESI) mass spectrum of the intact labelled CelB indicated that the inactivator had labelled the enzyme stoichiometrically. Reactivation of the trapped intermediate occurred spontaneously (kH2O = 0.0022 min-1) or via transglycosylation, with cellobiose acting as an acceptor ligand (kreact = 0.024 min-1, Kreact = 54 mM). Digestion of the labelled enzyme by pepsin followed by LC–ESI–tandem MS (MS–MS) operating in neutral loss mode identified a labelled, singly charged peptide of m/z 947.5 Da. Isolation of this peptide by HPLC and subsequent collision-induced fragmentation by ESI–MS–MS produced a daughter-ion spectrum that corresponded to a sequence (QTEIM) containing Glu-120. The nucleophile Glu-120 and the putative acid–base catalyst Glu-203 are conserved in all known family-12 sequences.
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11

Ferreira, L. M. A., G. P. Hazlewood, P. J. Barker, and H. J. Gilbert. "The cellodextrinase from Pseudomonas fluorescens subsp. cellulosa consists of multiple functional domains." Biochemical Journal 279, no. 3 (November 1, 1991): 793–99. http://dx.doi.org/10.1042/bj2790793.

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A genomic library of Pseudomonas fluorescens subsp. cellulosa DNA was constructed in pUC18 and Escherichia coli recombinants expressing 4-methylumbelliferyl beta-D-cellobioside-hydrolysing activity (MUCase) were isolated. Enzyme produced by MUCase-positive clones did not hydrolyse either cellobiose or cellotriose but converted cellotetraose into cellobiose and cleaved cellopentaose and cellohexaose, producing a mixture of cellobiose and cellotriose. There was no activity against CM-cellulose, insoluble cellulose or xylan. On this basis, the enzyme is identified as an endo-acting cellodextrinase and is designated cellodextrinase C (CELC). Nucleotide sequencing of the gene (celC) which directs the synthesis of CELC revealed an open reading frame of 2153 bp, encoding a protein of Mr 80,189. The deduced primary sequence of CELC was confirmed by the Mr of purified CELC (77,000) and by the experimentally determined N-terminus of the enzyme which was identical with residues 38-47 of the translated sequence. The N-terminal region of CELC showed strong homology with endoglucanase, xylanases and an arabinofuranosidase of Ps. fluorescens subsp. cellulosa; homologous sequences included highly conserved serine-rich regions. Full-length CELC bound tightly to crystalline cellulose. Truncated forms of celC from which the DNA sequence encoding the conserved domain had been deleted, directed the synthesis of a functional cellodextrinase that did not bind to crystalline cellulose. This is consistent with the N-terminal region of CELC comprising a non-catalytic cellulose-binding domain which is distinct from the catalytic domain. The role of the cellulose-binding region is discussed.
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12

Bhat, M. K. "Potential application of cellulase and hemicellulase assay techniques for assessing the forage quality and performance of rumen micro-organisms." BSAP Occasional Publication 22 (1998): 290–93. http://dx.doi.org/10.1017/s0263967x00032900.

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Cellulose and hemicellulose are the major structural polysaccharides of plant cell wall. The efficient utilization of these polysaccharides by ruminants is often restricted by the presence of lignin. Cellulose and hemicellulose are hydrolysed by a group of enzymes called cellulases and hemicellulases. The present paper describes the cellulase and hemicellulase assay methods and their potential applications.Carboxymethyl (CM)-cellulose, Avicel, cellobiose, xylobiose, p-nitrophenyl-p β-D-glucoside (pNPG), p-nitrophenyl-β-D-cellobioside (pNPC), p-nitrophenyl-β-D-xyloside (pNPX) and p-nitrophenyl- α-L-arabinofuranoside (pNPAf) were from Sigma. Birchwood xylan and filter paper are from Carl Roth GmbH and Co., Germany and Whatman International Ltd, UK, respectively. H3P04-Swollen cellulose and 4-O-methyl-α-D-glucuronyl-xylotriose (mGpA-Xyl3) were prepared as described (Wood, 1988; Khandkeet al., 1989a).
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13

Fan, Yufan, Yi Li, Yiyi Zhang, and Keshuo Shi. "Mechanism Analysis of Ethanol Production from Cellulosic Insulating Paper Based on Reaction Molecular Dynamics." Polymers 14, no. 22 (November 14, 2022): 4918. http://dx.doi.org/10.3390/polym14224918.

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The paper/oil system is the main component of transformer insulation. Indicator plays a vital role in assessing the aging condition of local hot spots of transformer insulation paper. The cellulosic insulating paper is mainly composed of cellobiose. This study uses the molecular dynamics method based on reactive force field (ReaxFF) to pyrolyze the insulating paper. Various production paths of ethanol were studied at the atomic level through ReaxFF simulations. A model consisting of 40 cellobioses was established for repeated simulation at 500 K–3000 K. Besides, to explore the relationship between the intermediate products and ethanol, the combination model of intermediate products (levoglucosan, acetaldehyde, 2,2-dihydroxyacetaldehyde) was established for repeated simulation. The simulation results showed that the increase in temperature can accelerate the production of ethanol from insulating paper and its pyrolysis intermediate products, which matched the related experimental results. This study can provide an effective reference for the use of ethanol as an indicator to assess the aging condition of the local hot spots of transformers.
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14

Maas, Lori K., and Thomas L. Glass. "Cellobiose uptake by the cellulolytic ruminai anaerobe Fibrobacter (Bacteroides) succinogenes." Canadian Journal of Microbiology 37, no. 2 (February 1, 1991): 141–47. http://dx.doi.org/10.1139/m91-021.

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Cellobiose transport by the cellulolytic ruminal anaerobe Fibrobacter (Bacteroides) succinogenes was measured using randomly tritiated cellobiose. When assayed at the same concentration (1 mM), total cellobiose uptake was one-fourth to one-third that of total glucose uptake. The abilities of F. succinogenes to transport cellobiose or glucose were not affected by the sugar on which the cells were grown. Aspects of the simultaneous transport of [14C(U)]glucose and [3H(G)]cellobiose, the failure of high concentrations of cold glucose to compete with hypothetical [3H(G)] glucose (derived externally from [3H(G)]cellobiose), and differential metal-ion stimulation of cellobiose transport indicate a cellobiose permease, rather than cellobiase plus glucose permease, was responsible for cellobiose transport. Glucose (10-fold molar excess) partially inhibited cellobiose transport. This was enhanced by prior incubation of the cells with glucose, suggesting subsequent metabolism of the glucose was responsible for the inhibition. Compounds interfering with electron transport or maintenance of transmembrane ion gradients inhibited cellobiose uptake, indicating that active transport rather than a phosphoenolpyruvate:phosphotransferase system catalyzed cellobiose transport. Na+, but not Li+, stimulated cellobiose transport. Key words: Fibrobacter (Bacteroides) succinogenes, cellobiose transport, rumen bacteria.
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15

Sulzenbacher, Gerlind, Martin Schülein, and Gideon J. Davies. "Structure of the Endoglucanase I fromFusariumoxysporum: Native, Cellobiose, and 3,4-Epoxybutyl β-d-Cellobioside-Inhibited Forms, at 2.3 Å Resolution†,‡." Biochemistry 36, no. 19 (May 1997): 5902–11. http://dx.doi.org/10.1021/bi962963+.

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16

Rao, A. Ramachandra, I. S. Gur, and Hari L. Bhatnagar. "Thermal studies on cellobiose and cellobiose halobenzoates." Thermochimica Acta 117 (July 1987): 139–55. http://dx.doi.org/10.1016/0040-6031(87)88110-8.

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17

Kitaoka, Motomitsu, Chika Aoyagi, and Kiyoshi Hayashi. "Colorimetric Quantification of Cellobiose Employing Cellobiose Phosphorylase." Analytical Biochemistry 292, no. 1 (May 2001): 163–66. http://dx.doi.org/10.1006/abio.2001.5049.

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18

Ha, Suk-Jin, Heejin Kim, Yuping Lin, Myoung-Uoon Jang, Jonathan M. Galazka, Tae-Jip Kim, Jamie H. D. Cate, and Yong-Su Jin. "Single Amino Acid Substitutions in HXT2.4 from Scheffersomyces stipitis Lead to Improved Cellobiose Fermentation by Engineered Saccharomyces cerevisiae." Applied and Environmental Microbiology 79, no. 5 (December 21, 2012): 1500–1507. http://dx.doi.org/10.1128/aem.03253-12.

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ABSTRACTSaccharomyces cerevisiaecannot utilize cellobiose, but this yeast can be engineered to ferment cellobiose by introducing both cellodextrin transporter (cdt-1) and intracellular β-glucosidase (gh1-1) genes fromNeurospora crassa. Here, we report that an engineeredS. cerevisiaestrain expressing the putative hexose transporter geneHXT2.4fromScheffersomyces stipitisandgh1-1can also ferment cellobiose. This result suggests that HXT2.4p may function as a cellobiose transporter whenHXT2.4is overexpressed inS. cerevisiae. However, cellobiose fermentation by the engineered strain expressingHXT2.4andgh1-1was much slower and less efficient than that by an engineered strain that initially expressedcdt-1andgh1-1. The rate of cellobiose fermentation by theHXT2.4-expressing strain increased drastically after serial subcultures on cellobiose. Sequencing and retransformation of the isolated plasmids from a single colony of the fast cellobiose-fermenting culture led to the identification of a mutation (A291D) in HXT2.4 that is responsible for improved cellobiose fermentation by the evolvedS. cerevisiaestrain. Substitutions for alanine (A291) of negatively charged amino acids (A291E and A291D) or positively charged amino acids (A291K and A291R) significantly improved cellobiose fermentation. The mutant HXT2.4(A291D) exhibited 1.5-fold higherKmand 4-fold higherVmaxvalues than those from wild-type HXT2.4, whereas the expression levels were the same. These results suggest that the kinetic properties of wild-type HXT2.4 expressed inS. cerevisiaeare suboptimal, and mutations of A291 into bulky charged amino acids might transform HXT2.4p into an efficient transporter, enabling rapid cellobiose fermentation by engineeredS. cerevisiaestrains.
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19

Oh, Eun Joong, Jeffrey M. Skerker, Soo Rin Kim, Na Wei, Timothy L. Turner, Matthew J. Maurer, Adam P. Arkin, and Yong-Su Jin. "Gene Amplification on Demand Accelerates Cellobiose Utilization in Engineered Saccharomyces cerevisiae." Applied and Environmental Microbiology 82, no. 12 (April 15, 2016): 3631–39. http://dx.doi.org/10.1128/aem.00410-16.

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ABSTRACTEfficient microbial utilization of cellulosic sugars is essential for the economic production of biofuels and chemicals. Although the yeastSaccharomyces cerevisiaeis a robust microbial platform widely used in ethanol plants using sugar cane and corn starch in large-scale operations, glucose repression is one of the significant barriers to the efficient fermentation of cellulosic sugar mixtures. A recent study demonstrated that intracellular utilization of cellobiose by engineered yeast expressing a cellobiose transporter (encoded bycdt-1) and an intracellular β-glucosidase (encoded bygh1-1) can alleviate glucose repression, resulting in the simultaneous cofermentation of cellobiose and nonglucose sugars. Here we report enhanced cellobiose fermentation by engineered yeast expressingcdt-1andgh1-1through laboratory evolution. Whencdt-1andgh1-1were integrated into the genome of yeast, the single copy integrant showed a low cellobiose consumption rate. However, cellobiose fermentation rates by engineered yeast increased gradually during serial subcultures on cellobiose. Finally, an evolved strain exhibited a 15-fold-higher cellobiose fermentation rate. To identify the responsible mutations in the evolved strain, genome sequencing was performed. Interestingly, no mutations affecting cellobiose fermentation were identified, but the evolved strain contained 9 copies ofcdt-1and 23 copies ofgh1-1. We also traced the copy numbers ofcdt-1andgh1-1of mixed populations during the serial subcultures. The copy numbers ofcdt-1andgh1-1in the cultures increased gradually with similar ratios as cellobiose fermentation rates of the cultures increased. These results suggest that the cellobiose assimilation pathway (transport and hydrolysis) might be a rate-limiting step in engineered yeast and copies of genes coding for metabolic enzymes might be amplified in yeast if there is a growth advantage. This study indicates that on-demand gene amplification might be an efficient strategy for yeast metabolic engineering.IMPORTANCEIn order to enable rapid and efficient fermentation of cellulosic hydrolysates by engineered yeast, we delve into the limiting factors of cellobiose fermentation by engineered yeast expressing a cellobiose transporter (encoded bycdt-1) and an intracellular β-glucosidase (encoded bygh1-1). Through laboratory evolution, we isolated mutant strains capable of fermenting cellobiose much faster than a parental strain. Genome sequencing of the fast cellobiose-fermenting mutant reveals that there are massive amplifications ofcdt-1andgh1-1in the yeast genome. We also found positive and quantitative relationships between the rates of cellobiose consumption and the copy numbers ofcdt-1andgh1-1in the evolved strains. Our results suggest that the cellobiose assimilation pathway (transport and hydrolysis) might be a rate-limiting step for efficient cellobiose fermentation. We demonstrate the feasibility of optimizing not only heterologous metabolic pathways in yeast through laboratory evolution but also on-demand gene amplification in yeast, which can be broadly applicable for metabolic engineering.
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20

Kajikawa, Hiroshi, and Shigehiko Masaki. "Cellobiose Transport by Mixed Ruminal Bacteria from a Cow." Applied and Environmental Microbiology 65, no. 6 (June 1, 1999): 2565–69. http://dx.doi.org/10.1128/aem.65.6.2565-2569.1999.

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ABSTRACT The transport of cellobiose in mixed ruminal bacteria harvested from a holstein cow fed an Italian ryegrass hay was determined in the presence of nojirimycin-1-sulfate, which almost inhibited cellobiase activity. The kinetic parameters of cellobiose uptake were 14 μM for the Km and 10 nmol/min/mg of protein for theV max. Extracellular and cell-associated cellobiases were detected in the rumen, with both showing higherV max values and lower affinities than those determined for cellobiose transport. The proportion of cellobiose that was directly transported before it was extracellularly degraded into glucose increased as the cellobiose concentration decreased, reaching more than 20% at the actually observed levels of cellobiose in the rumen, which were less than 0.02 mM. The inhibitor experiment showed that cellobiose was incorporated into the cells mainly by the phosphoenolpyruvate phosphotransferase system and partially by an ATP-dependent and proton-motive-force-independent active transport system. This finding was also supported by determinations of phosphoenolpyruvate phosphotransferase-dependent NADH oxidation with cellobiose and the effects of artificial potentials on cellobiose transport. Cellobiose uptake was sensitive to a decrease in pH (especially below 6.0), and it was weakly but significantly inhibited in the presence of glucose.
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21

Moré, Margret Irmgard, Elisa Postrach, Gordana Bothe, Sonja Heinritz, and Ralf Uebelhack. "A Dose-Escalation Study Demonstrates the Safety and Tolerability of Cellobiose in Healthy Subjects." Nutrients 12, no. 1 (December 25, 2019): 64. http://dx.doi.org/10.3390/nu12010064.

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The disaccharide and innovative ingredient cellobiose, consisting of two β-glucose molecules linked by a β(1→4) bond is the main component of cellulose. Cellobiose can be used within a wide variety of foodstuffs and functional foods as a low-caloric bulking agent or as a substitute for lactose. For purposes of industrial large-scale production, cellobiose is produced by an enzymatic reaction in which sucrose and glucose are converted to cellobiose and fructose. The goal of this single-arm, dose-escalation study was to evaluate the safety and tolerability of cellobiose and to determine the maximum tolerated dose of cellobiose in healthy subjects. Following a baseline period, consecutive cohorts of six subjects each consumed either single doses of 10, 15, 20 and 25 g, while 12 subjects each received multiple doses of 15 g or 20 g cellobiose (twice daily, 14 days). The main recorded parameters were stool consistency, gastrointestinal well-being (Gastrointestinal Symptom Rating Scale) and adverse events. In each highest single/multiple dosage group, some sensitive subjects experienced flatulence, borborygmus and/or transient diarrhoea. A 100% global tolerability rating makes 20 g cellobiose a tolerable dose for single use. For repeated consumption, we propose up to 15 g cellobiose twice daily (92.6% global tolerability rating). Cellobiose is a promising new ingredient with excellent tolerability.
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22

Kim, Dae-Hwan, and Won-Heong Lee. "Simultaneous Saccharification and Fermentation with Mutant Pichia stipitis Co-fermenting Cellobiose and Xylose." KSBB Journal 34, no. 4 (December 31, 2019): 284–90. http://dx.doi.org/10.7841/ksbbj.2019.34.4.284.

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23

Schlösser, Andreas, Jens Jantos, Karl Hackmann, and Hildgund Schrempf. "Characterization of the Binding Protein-Dependent Cellobiose and Cellotriose Transport System of the Cellulose Degrader Streptomyces reticuli." Applied and Environmental Microbiology 65, no. 6 (June 1, 1999): 2636–43. http://dx.doi.org/10.1128/aem.65.6.2636-2643.1999.

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ABSTRACT Streptomyces reticuli has an inducible ATP-dependent uptake system specific for cellobiose and cellotriose. By reversed genetics a gene cluster encoding components of a binding protein-dependent cellobiose and cellotriose ABC transporter was cloned and sequenced. The deduced gene products comprise a regulatory protein (CebR), a cellobiose binding lipoprotein (CebE), two integral membrane proteins (CebF and CebG), and the NH2-terminal part of an intracellular β-glucosidase (BglC). The gene for the ATP binding protein MsiK is not linked to the ceb operon. We have shown earlier that MsiK is part of two different ABC transport systems, one for maltose and one for cellobiose and cellotriose, in S. reticuli and Streptomyces lividans. Transcription of polycistronic cebEFG and bglC mRNAs is induced by cellobiose, whereas the cebR gene is transcribed independently. Immunological experiments showed that CebE is synthesized during growth with cellobiose and that MsiK is produced in the presence of several sugars at high or moderate levels. The described ABC transporter is the first one of its kind and is the only specific cellobiose/cellotriose uptake system of S. reticuli, since insertional inactivation of the cebEgene prevents high-affinity uptake of cellobiose.
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Yernool, Dinesh A., James K. McCarthy, Douglas E. Eveleigh, and Jin-Duck Bok. "Cloning and Characterization of the Glucooligosaccharide Catabolic Pathway β-Glucan Glucohydrolase and Cellobiose Phosphorylase in the Marine HyperthermophileThermotoga neapolitana." Journal of Bacteriology 182, no. 18 (September 15, 2000): 5172–79. http://dx.doi.org/10.1128/jb.182.18.5172-5179.2000.

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ABSTRACT Characterization in Thermotoga neapolitana of a catabolic gene cluster encoding two glycosyl hydrolases, 1,4-β-d-glucan glucohydrolase (GghA) and cellobiose phosphorylase (CbpA), and the apparent absence of a cellobiohydrolase (Cbh) suggest a nonconventional pathway for glucan utilization inThermotogales. GghA purified from T. neapolitana is a 52.5-kDa family 1 glycosyl hydrolase with optimal activity at pH 6.5 and 95°C. GghA releases glucose from soluble glucooligomers, with a preference for longer oligomers:k cat/Km values are 155.2, 76.0, and 9.9 mM−1 s−1 for cellotetraose, cellotriose, and cellobiose, respectively. GghA has broad substrate specificity, with specific activities of 236 U/mg towards cellobiose and 251 U/mg towards lactose. Withp-nitrophenyl-β-glucoside as the substrate, GghA exhibits biphasic kinetic behavior, involving both substrate- and end product-directed activation. Its capacity for transglycosylation is a factor in this activation. Cloning of gghA revealed a contiguous upstream gene (cbpA) encoding a 93.5-kDa cellobiose phosphorylase. Recombinant CbpA has optimal activity at pH 5.0 and 85°C. It has specific activity of 11.8 U/mg and aKm of 1.42 mM for cellobiose, but shows no activity towards other disaccharides or cellotriose. With its single substrate specificity and low Km for cellobiose (compared to GghA's Km of 28.6 mM), CbpA may be the primary enzyme for attacking cellobiose inThermotoga spp. By phosphorolysis of cellobiose, CbpA releases one activated glucosyl molecule while conserving one ATP molecule per disaccharide. CbpA is the first hyperthermophilic cellobiose phosphorylase to be characterized.
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Yang, Ling, Hong Peng, Hongwei He, Ling Liu, Guiming Fu, Yuhuan Liu, and Yin Wan. "Interaction mechanism between cellobiose and imidazolium halide-based ionic liquids." BioResources 18, no. 1 (January 11, 2023): 1590–601. http://dx.doi.org/10.15376/biores.18.1.1590-1601.

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Ionic liquids (ILs) are excellent solvents for cellulose, but the dissolution mechanism is not deeply understood. In the present study, cellobiose was used as a model of cellulose, and the imidazolium halide-based ILs with the same cation of 1-butyl-3-methylimidazolium (Bmim+) including BmimCl, BmimBr, and BmimI were used as solvents. The interaction mechanism between the ILs and cellobiose was analyzed by carbon-13 nuclear magnetic resonance (13C NMR). The results showed that the strength of hydrogen bonds formed between the hydroxyl groups of cellobiose and the ILs was greatly affected by the position of hydroxyl groups and the electro-negativity and size of the anions. Compared with the secondary alcoholic hydroxyl groups, the primary alcoholic hydroxyl groups (C6–OH and C12–OH) on the glucopyranose rings of cellobiose more easily formed hydrogen bonds with the ILs. The strength of hydrogen bonds formed between the protons on the imidazolium cation and cellobiose varied with the positions of the protons. The formation of hydrogen bonds between the halogen anions and cellobiose was the main reason for the dissolution of cellobiose in the ILs. The ability of the three ILs to form hydrogen bonds with cellobiose followed the order: BmimCl > BmimBr > BmimI.
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26

Ng, Thomas K., and J. G. Zeikus. "Synthesis of [14C]Cellobiose with Clostridium thermocellum Cellobiose Phosphorylase." Applied and Environmental Microbiology 52, no. 4 (1986): 902–4. http://dx.doi.org/10.1128/aem.52.4.902-904.1986.

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27

Morpeth, F. F. "Some properties of cellobiose oxidase from the white-rot fungus Sporotrichum pulverulentum." Biochemical Journal 228, no. 3 (June 15, 1985): 557–64. http://dx.doi.org/10.1042/bj2280557.

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Cellobiose oxidase from the white-rot fungus Sporotrichum pulverulentum has been purified to homogeneity by a new procedure. The carbohydrate and amino acid compositions of the enzyme have been determined. Cellobiose oxidase contains FAD and cytochrome b prosthetic groups. Mr of the enzyme has been estimated at 74400 by sedimentation equilibrium. The enzyme is a monomer. Optical, fluorescence and e.p.r. spectra of oxidized and reduced cellobiose oxidase have been determined. A preliminary investigation of the substrate specificity of cellobiose oxidase reveals that disaccharides and even some insoluble polysaccharides are substrates, but not monosaccharides. Strong substrate inhibition is seen at high concentrations of cellobiose. This effect is particularly marked when oxygen is the electron acceptor. Cellobiose oxidase is unusual among flavoproteins, since it stabilizes the red anionic flavin semiquinone and forms a sulphite adduct, yet appears to produce the superoxide anion as its primary reduced oxygen product.
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28

Hildebrand, Amanda, Edyta Szewczyk, Hui Lin, Takao Kasuga, and Zhiliang Fan. "Engineering Neurospora crassa for Improved Cellobiose and Cellobionate Production." Applied and Environmental Microbiology 81, no. 2 (November 7, 2014): 597–603. http://dx.doi.org/10.1128/aem.02885-14.

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ABSTRACTWe report engineeringNeurospora crassato improve the yield of cellobiose and cellobionate from cellulose. A previously engineered strain ofN. crassa(F5) with six of seven β-glucosidase (bgl) genes knocked out was shown to produce cellobiose and cellobionate directly from cellulose without the addition of exogenous cellulases. In this study, the F5 strain was further modified to improve the yield of cellobiose and cellobionate from cellulose by increasing cellulase production and decreasing product consumption. The effects of two catabolite repression genes,cre-1andace-1, on cellulase production were investigated. The F5 Δace-1mutant showed no improvement over the wild type. The F5 Δcre-1and F5 Δace-1Δcre-1strains showed improved cellobiose dehydrogenase and exoglucanase expression. However, this improvement in cellulase expression did not lead to an improvement in cellobiose or cellobionate production. The cellobionate phosphorylase gene (ndvB) was deleted from the genome of F5 Δace-1Δcre-1to prevent the consumption of cellobiose and cellobionate. Despite a slightly reduced hydrolysis rate, the F5 Δace-1Δcre-1ΔndvBstrain converted 75% of the cellulose consumed to the desired products, cellobiose and cellobionate, compared to 18% converted by the strain F5 Δace-1Δcre-1.
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29

Matheron, Christelle, Anne-Marie Delort, Geneviève Gaudet, and Evelyne Forano. "Simultaneous but differential metabolism of glucose and cellobiose inFibrobacter succinogenescells, studied by in vivo13C-NMR." Canadian Journal of Microbiology 42, no. 11 (November 1, 1996): 1091–99. http://dx.doi.org/10.1139/m96-140.

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Kinetics of [1-13C]glucose utilization were monitored by in vivo NMR spectroscopy on resting cells of Fibrobacter succinogenes, in the presence of 32 mM [1-13C]glucose, 32 mM [1-13C]glucose and 64 mM unlabelled glucose, or 32 mM [1-13C]glucose and 32 mM unlabelled cellobiose. A similar production of acetate and succinate and a similar storage of glycogen were observed whatever the exogenous substrate. The presence of cellobiose or that of an equivalent amount of glucose did not reduce [1-13C]glucose incorporation to the same extent. Glucose seemed preferentially used for glycogen storage and energy production, while part of the cellobiose appeared to be used for cellodextrin synthesis. Both cellobiase and cellobiose phosphorylase activities were assayed in cell-free extracts. Finally, the intracellular concentration of glucose 6-phosphate was increased by over threefold when cells metabolized cellobiose (alone or in parallel to glucose) as compared with the metabolism of glucose alone.Key words: Fibrobacter succinogenes, rumen, glucose 6-phosphate, cellobiose, NMR.
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30

Sekar, Ramanan, Hyun-Dong Shin, and Rachel Chen. "Engineering Escherichia coli Cells for Cellobiose Assimilation through a Phosphorolytic Mechanism." Applied and Environmental Microbiology 78, no. 5 (December 22, 2011): 1611–14. http://dx.doi.org/10.1128/aem.06693-11.

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ABSTRACTWe report here the first engineering effort forEscherichia colibiocatalysts to assimilate cellobiose through a phosphorolytic mechanism. Cytoplasmic expression of theSaccharophaguscellobiose phosphorylase was shown to enableE. colito use cellobiose. Subsequent knockout and complementation studies provided solid evidence that the endogenous LacY was responsible for the transport of cellobiose.
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31

Freer, Shelby N., and Christopher D. Skory. "Production of β-glucosidase and diauxic usage of sugar mixtures byCandida molischiana." Canadian Journal of Microbiology 42, no. 5 (May 1, 1996): 431–36. http://dx.doi.org/10.1139/m96-059.

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The fermentation of cellobiose is a rare trait among yeasts. Of the 308 yeast species that utilize cellobiose aerobically, only 12 species ferment it, and only 2 species, Candida molischiana and Candida wickerhamii, also ferment cellodextrins. Candida molischiana produced β-glucosidase activity on all carbon sources tested, except glucose, mannose, and fructose. When these sugars were added to cultures growing on cellobiose, the synthesis of β-glucosidase ceased. However, the total amount of enzyme activity remained constant, indicating that the C. molischiana β-glucosidase is catabolite repressed and not catabolite inactivated. When grown in medium initially containing glucose plus xylose, cellobiose, maltose, mannitol, or glucitol, C. molischiana preferentially utilized glucose and produced little β-glucosidase activity until glucose was nearly depleted from the medium. When grown in medium containing cellobiose plus either fructose or mannose, the yeast preferentially utilized the monosaccharides and produced little β-glucosidase activity. Candida molischiana produced β-glucosidase and co-utilized cellobiose and xylose, maltose, or trehalose. Glucose and fructose, mannose, or trehalose were co-utilized; however, no β-glucosidase activity was detected. Thus, the order of substrate preference groups appeared to be (glucose, trehalose, fructose, mannose) > (cellobiose, maltose, xylose) > (mannitol, glucitol).Key words: glucose repression, trehalase, diauxic utilization, yeast.
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32

Jones, G. D., and M. T. Wilson. "Rapid kinetic studies of the reduction of cellobiose oxidase from the white-rot fungus Sporotrichum pulverulentum by cellobiose." Biochemical Journal 256, no. 3 (December 15, 1988): 713–18. http://dx.doi.org/10.1042/bj2560713.

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The reactions between cellobiose and cellobiose oxidase were investigated by stopped-flow spectrophotometry. Under anaerobic conditions rapid reduction of the associated flavin is followed by slower reduction of cytochrome b. The kinetic difference spectra are reported. The rate of flavin reduction depends on the cellobiose concentration (with an apparent second-order rate constant of approx. 10(5) M-1.s-1) but reaches a rate limit of approx. 20 s-1. In contrast, the rate of cytochrome b reduction decreases at high cellobiose concentrations. Kinetic titrations of the flavin and cytochrome b moieties yield the stoichiometries of the separate reactions, i.e. the number of moles of cellobiose needed to fully reduce 1 mole of each redox component. The rate constant for cytochrome b reduction, unlike that for flavin reduction, increased with enzyme concentration, prompting the conclusion that any given cytochrome b centre is reduced preferentially by flavin groups in different molecules rather than by its partner flavin within the same monomer. These data are discussed in the context of a scheme that rationalizes them and accounts for the overall stoichiometry in which three two-electron donors (cellobiose molecules) reduce two three-electron acceptors (the flavin-cytochrome b of cellobiose oxidase).
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Koning, Sonja M., Marieke G. L. Elferink, Wil N. Konings, and Arnold J. M. Driessen. "Cellobiose Uptake in the Hyperthermophilic ArchaeonPyrococcus furiosus Is Mediated by an Inducible, High-Affinity ABC Transporter." Journal of Bacteriology 183, no. 17 (September 1, 2001): 4979–84. http://dx.doi.org/10.1128/jb.183.17.4979-4984.2001.

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ABSTRACT The hyperthermophilic archaeon Pyrococcus furiosuscan utilize different β-glucosides, like cellobiose and laminarin. Cellobiose uptake occurs with high affinity (K m = 175 nM) and involves an inducible binding protein-dependent transport system. The cellobiose binding protein (CbtA) was purified from P. furiosusmembranes to homogeneity as a 70-kDa glycoprotein. CbtA not only binds cellobiose but also cellotriose, cellotetraose, cellopentaose, laminaribiose, laminaritriose, and sophorose. The cbtAgene was cloned and functionally expressed in Escherichia coli. cbtA belongs to a gene cluster that encodes a transporter that belongs to the Opp family of ABC transporters.
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34

Yi-Heng, Zhang Percival, and Lee R. Lynd. "Regulation of Cellulase Synthesis in Batch and Continuous Cultures of Clostridium thermocellum." Journal of Bacteriology 187, no. 1 (January 1, 2005): 99–106. http://dx.doi.org/10.1128/jb.187.1.99-106.2005.

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ABSTRACT Regulation of cell-specific cellulase synthesis (expressed in milligrams of cellulase per gram [dry weight] of cells) by Clostridium thermocellum was investigated using an enzyme-linked immunosorbent assay protocol based on antibody raised against a peptide sequence from the scaffoldin protein of the cellulosome (Zhang and Lynd, Anal. Chem. 75:219-227, 2003). The cellulase synthesis in Avicel-grown batch cultures was ninefold greater than that in cellobiose-grown batch cultures. In substrate-limited continuous cultures, however, the cellulase synthesis with Avicel-grown cultures was 1.3- to 2.4-fold greater than that in cellobiose-grown cultures, depending on the dilution rate. The differences between the cellulase yields observed during carbon-limited growth on cellulose and the cellulase yields observed during carbon-limited growth on cellobiose at the same dilution rate suggest that hydrolysis products other than cellobiose affect cellulase synthesis during growth on cellulose and/or that the presence of insoluble cellulose triggers an increase in cellulase synthesis. Continuous cellobiose-grown cultures maintained either at high dilution rates or with a high feed substrate concentration exhibited decreased cellulase synthesis; there was a large (sevenfold) decrease between 0 and 0.2 g of cellobiose per liter, and there was a much more gradual further decrease for cellobiose concentrations >0.2 g/liter. Several factors suggest that cellulase synthesis in C. thermocellum is regulated by catabolite repression. These factors include: (i) substantially higher cellulase yields observed during batch growth on Avicel than during batch growth on cellobiose, (ii) a strong negative correlation between the cellobiose concentration and the cellulase yield in continuous cultures with varied dilution rates at a constant feed substrate concentration and also with varied feed substrate concentrations at a constant dilution rate, and (iii) the presence of sequences corresponding to key elements of catabolite repression systems in the C. thermocellum genome.
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35

Zhang, Yi-Heng Percival, and Lee R. Lynd. "Kinetics and Relative Importance of Phosphorolytic and Hydrolytic Cleavage of Cellodextrins and Cellobiose in Cell Extracts of Clostridium thermocellum." Applied and Environmental Microbiology 70, no. 3 (March 2004): 1563–69. http://dx.doi.org/10.1128/aem.70.3.1563-1569.2004.

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ABSTRACT Rates of phosphorolytic cleavage of β-glucan substrates were determined for cell extracts from Clostridium thermocellum ATCC 27405 and were compared to rates of hydrolytic cleavage. Reactions with cellopentaose and cellobiose were evaluated for both cellulose (Avicel)- and cellobiose-grown cultures, with more limited data also obtained for cellotetraose. To measure the reaction rate in the chain-shortening direction at elevated temperatures, an assay protocol was developed featuring discrete sampling at 60�C followed by subsequent analysis of reaction products (glucose and glucose-1-phosphate) at 35�C. Calculated rates of phosphorolytic cleavage for cell extract from Avicel-grown cells exceeded rates of hydrolytic cleavage by ≥20-fold for both cellobiose and cellopentaose over a 10-fold range of β-glucan concentrations (0.5 to 5 mM) and for cellotetraose at a single concentration (2 mM). Rates of phosphorolytic cleavage of β-glucosidic bonds measured in cell extracts were similar to rates observed in growing cultures. Comparisons of V max values indicated that cellobiose- and cellodextrin-phosphorylating activities are synthesized during growth on both cellobiose and Avicel but are subject to some degree of metabolic control. The apparent K m for phosphorolytic cleavage was lower for cellopentaose (mean value for Avicel- and cellobiose-grown cells, 0.61 mM) than for cellobiose (mean value, 3.3 mM).
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36

Dellaglio, Franco, Sandra Torriani, and Giovanna E. Felis. "Reclassification of Lactobacillus cellobiosus Rogosa et al. 1953 as a later synonym of Lactobacillus fermentum Beijerinck 1901." International Journal of Systematic and Evolutionary Microbiology 54, no. 3 (May 1, 2004): 809–12. http://dx.doi.org/10.1099/ijs.0.02947-0.

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The name Lactobacillus cellobiosus is validly published, but the species is often neglected in taxonomic studies, due to its high similarity to Lactobacillus fermentum. In the present paper, literature data concerning the two species were reviewed. Phylogenetic placement of L. cellobiosus was obtained based on 16S rDNA sequences, and genetic similarity was further investigated by comparing partial recA gene sequences for the type strains of L. cellobiosus and L. fermentum. Based on the high identity values for 16S rDNA (99 %) and recA gene (98 %) sequences, the results of DNA–DNA hybridization assays and phenotypic traits available from the literature, it is proposed that L. cellobiosus be reclassified and, as a rule of priority, renamed as L. fermentum, the first described species.
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37

Varrot, Annabelle, Torben P. Frandsen, Hugues Driguez, and Gideon J. Davies. "Structure of theHumicola insolenscellobiohydrolase Cel6A D416A mutant in complex with a non-hydrolysable substrate analogue, methyl cellobiosyl-4-thio-β-cellobioside, at 1.9 Å." Acta Crystallographica Section D Biological Crystallography 58, no. 12 (November 26, 2002): 2201–4. http://dx.doi.org/10.1107/s0907444902017006.

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38

Shulami, Smadar, Arie Zehavi, Valery Belakhov, Rachel Salama, Shifra Lansky, Timor Baasov, Gil Shoham, and Yuval Shoham. "Cross-utilization of β-galactosides and cellobiose in Geobacillus stearothermophilus." Journal of Biological Chemistry 295, no. 31 (June 3, 2020): 10766–80. http://dx.doi.org/10.1074/jbc.ra120.014029.

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Strains of the Gram-positive, thermophilic bacterium Geobacillus stearothermophilus possess elaborate systems for the utilization of hemicellulolytic polysaccharides, including xylan, arabinan, and galactan. These systems have been studied extensively in strains T-1 and T-6, representing microbial models for the utilization of soil polysaccharides, and many of their components have been characterized both biochemically and structurally. Here, we characterized routes by which G. stearothermophilus utilizes mono- and disaccharides such as galactose, cellobiose, lactose, and galactosyl-glycerol. The G. stearothermophilus genome encodes a phosphoenolpyruvate carbohydrate phosphotransferase system (PTS) for cellobiose. We found that the cellobiose-PTS system is induced by cellobiose and characterized the corresponding GH1 6-phospho-β-glucosidase, Cel1A. The bacterium also possesses two transport systems for galactose, a galactose-PTS system and an ABC galactose transporter. The ABC galactose transport system is regulated by a three-component sensing system. We observed that both systems, the sensor and the transporter, utilize galactose-binding proteins that also bind glucose with the same affinity. We hypothesize that this allows the cell to control the flux of galactose into the cell in the presence of glucose. Unexpectedly, we discovered that G. stearothermophilus T-1 can also utilize lactose and galactosyl-glycerol via the cellobiose-PTS system together with a bifunctional 6-phospho-β-gal/glucosidase, Gan1D. Growth curves of strain T-1 growing in the presence of cellobiose, with either lactose or galactosyl-glycerol, revealed initially logarithmic growth on cellobiose and then linear growth supported by the additional sugars. We conclude that Gan1D allows the cell to utilize residual galactose-containing disaccharides, taking advantage of the promiscuity of the cellobiose-PTS system.
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39

Lerat, Sylvain, Anne-Marie Simao-Beaunoir, Run Wu, Nathalie Beaudoin, and Carole Beaulieu. "Involvement of the Plant Polymer Suberin and the Disaccharide Cellobiose in Triggering Thaxtomin A Biosynthesis, a Phytotoxin Produced by the Pathogenic Agent Streptomyces scabies." Phytopathology® 100, no. 1 (January 2010): 91–96. http://dx.doi.org/10.1094/phyto-100-1-0091.

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Streptomyces scabies is a gram-positive soil bacterium recognized as the main causal agent of common scab. Pathogenicity in Streptomyces spp. depends on their capacity to synthesize phytotoxins called thaxtomins. Genes involved in biosynthesis of these secondary metabolites are known to be induced by cellobiose, a plant disaccharide. However, growth of S. scabies in a minimal medium containing cellobiose as a carbon source is very poor and only generates traces of thaxtomins. The effect of suberin, a lipid plant polymer, on thaxtomin A biosynthesis and the expression of genes involved in its biosynthetic pathway was analyzed. S. scabies was grown in a starch-containing minimal medium supplemented with cellobiose (0.5%), suberin (0.1%), or both. The presence of both cellobiose and suberin doubled bacterial growth and triggered thaxtomin A production, which correlated with the upregulation (up to 342-fold) of genes involved in thaxtomins synthesis. The addition of either suberin or cellobiose alone did not affect these parameters. Suberin appeared to stimulate the onset of secondary metabolism, which is a prerequisite to the production of molecules such as thaxtomin A, while cellobiose induced the biosynthesis of this secondary metabolite.
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40

Chen, Shaolin, and David B. Wilson. "Proteomic and Transcriptomic Analysis of Extracellular Proteins and mRNA Levels in Thermobifida fusca Grown on Cellobiose and Glucose." Journal of Bacteriology 189, no. 17 (June 29, 2007): 6260–65. http://dx.doi.org/10.1128/jb.00584-07.

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ABSTRACT Thermobifida fusca secretes proteins that carry out plant cell wall degradation. Using two-dimensional electrophoresis, the extracellular proteome of T. fusca grown on cellobiose was compared to that of cells grown on glucose. Extracellular proteins, the expression of which is induced by cellobiose, mainly are cellulases and cellulose-binding proteins. Other major extracellular proteins induced by cellobiose include a xylanase (Xyl10A) and two unknown proteins, the C-terminal regions of which are homologous to a lytic transglycosylase goose egg white lysozyme domain and an NLPC_P60 domain (which defines a family of cell wall peptidases), respectively. Transcriptional analysis of genes encoding cellobiose-induced proteins suggests that their expression is controlled at the transcriptional level and that their expression also is induced by cellulose. Some other major extracellular proteins produced by T. fusca grown on both cellobiose and glucose include Lam81A and three unknown proteins that are homologous to aminopeptidases and xylanases or that contain a putative NLPC_P60 domain.
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41

Moe, Størker, Anne Holen1†, and Tove Schult2††. "4-O-β-d-GLUCOPYRANOSYL-d-GLUCONIC ACID (CELLOBIONIC ACID) PRODUCED BY OZONATION OF CELLOBIOSE: ISOLATION BY HPLC AND ASSIGNMENT OF NMR CHEMICAL SHIFTS." Journal of Carbohydrate Chemistry 21, no. 6 (2002): 513–20. http://dx.doi.org/10.1081/car-120016850.

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42

Parker, L. L., and B. G. Hall. "A fourth Escherichia coli gene system with the potential to evolve beta-glucoside utilization." Genetics 119, no. 3 (July 1, 1988): 485–90. http://dx.doi.org/10.1093/genetics/119.3.485.

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Abstract Escherichia coli K12 is being used to study the potential for adaptive evolution that is present in the genome of a single organism. Wild-type E. coli K12 do not utilize any of the beta-glucoside sugars arbutin, salicin or cellobiose. It has been shown that mutations at three cryptic loci allow utilization of these sugars. Mutations in the bgl operon allow inducible growth on arbutin and salicin while cel mutations allow constitutive utilization of cellobiose as well as arbutin and salicin. Mutations in a third cryptic locus, arbT, allow the transport of arbutin. A salicin+ arbutin+ cellobiose+ mutant has been isolated from a strain which is deleted for the both the bgl and cel operons. Because the mutant utilized salicin and cellobiose as well as arbutin, it is unlikely it is the result of a mutation in arbT. A second step mutant exhibited enhanced growth on salicin and a third step mutant showed better growth on cellobiose. A fourfold level of induction in response to arbutin and a twofold level of induction in response to salicin was observed when these mutants were assayed on the artificial substrate p-nitrophenyl-beta-D-glucoside. Although growth on cellobiose minimal medium can be detected after prolonged periods of time, these strains are severely inhibited by cellobiose in liquid medium. This system has been cloned and does not hybridize to either bgl or cel specific probes. We have designated this gene system the sac locus. The sac locus is a fourth set of genes with the potential for evolving to provide beta-glucoside utilization.
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43

Tsafrakidou, Panagiota, Konstantina Tsigkou, Argyro Bekatorou, Maria Kanellaki, and Athanasios A. Koutinas. "Anaerobic Acidogenic Fermentation of Cellobiose by Immobilized Cells: Prediction of Organic Acids Production by Response Surface Methodology." Processes 9, no. 8 (August 19, 2021): 1441. http://dx.doi.org/10.3390/pr9081441.

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Response surface methodology was used to derive a prediction model for organic acids production by anaerobic acidogenic fermentation of cellobiose, using a mixed culture immobilized on γ-alumina. Three parameters (substrate concentration, temperature, and initial pH) were evaluated. In order to determine the limits of the parameters, preliminary experiments at 37 °C were conducted using substrates of various cellobiose concentrations and pH values. Cellobiose was used as a model sugar for subsequent experiments with lignocellulosic biomass. The culture was well adapted to cellobiose by successive subculturing at 37 °C in synthetic media (with 100:5:1 COD:N:P ratio). The experimental data of successive batch fermentations were fitted into a polynomial model for the total organic acids concentration in order to derive a predictive model that could be utilized as a tool to predict fermentation results when lignocellulosic biomass is used as a substrate. The quadratic effect of temperature was the most significant, followed by the quadratic effect of initial pH and the linear effect of cellobiose concentration. The results corroborated the validity and effectiveness of the model.
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44

Ander, P., G. Sena-Martins, and J. C. Duarte. "Influence of cellobiose oxidase on peroxidases from Phanerochaete chrysosporium." Biochemical Journal 293, no. 2 (July 15, 1993): 431–35. http://dx.doi.org/10.1042/bj2930431.

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Reduction of H2O2-oxidized manganese peroxidase (MnP), lignin peroxidase and, to some extent, horseradish peroxidase, was studied in the presence of cellobiose oxidase (CbO) and cellobiose. It was found that the reversion rates for MnP compound II and lignin peroxidase compound II back to native enzymes increased significantly in the presence of CbO and cellobiose. However, the reduction of cytochrome c by CbO plus cellobiose was 40 times faster than the reduction of MnP compound II. Also, the lag phase before reversion to the native states decreased for all three peroxidases in the presence of CbO and cellobiose. Active CbO did not repress formation of compounds I or II of the peroxidases, and Mn2+/veratryl alcohol reduced compound II of the peroxidases much more rapidly than did active CbO. This indicates that, in the presence of Mn2+ or veratryl alcohol, MnP and lignin peroxidase can complete their catalytic cycles and function normally without interference from CbO. Without the presence of peroxidase substrates, active CbO reduced compound II of the above peroxidases.
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45

Adsul, Mukund, Jayant Khire, Kulbhushan Bastawde, and Digambar Gokhale. "Production of Lactic Acid from Cellobiose and Cellotriose by Lactobacillus delbrueckii Mutant Uc-3." Applied and Environmental Microbiology 73, no. 15 (June 8, 2007): 5055–57. http://dx.doi.org/10.1128/aem.00774-07.

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ABSTRACT Lactobacillus delbrueckii mutant Uc-3 utilizes both cellobiose and cellotriose efficiently, converting it into L(+) lactic acid. The enzyme activities of cellobiose and cellotriose utilization were determined for cell extracts, whole cells, and disrupted cells. Aryl-β-glucosidase activity was detected only for whole cells and disrupted cells, suggesting that these activities are cell bound. The mutant produced 90 g/liter of lactic acid from 100 g/liter of cellobiose with 2.25 g/liter/h productivity.
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46

Adin, Dawn M., Karen L. Visick, and Eric V. Stabb. "Identification of a Cellobiose Utilization Gene Cluster with Cryptic β-Galactosidase Activity in Vibrio fischeri." Applied and Environmental Microbiology 74, no. 13 (May 16, 2008): 4059–69. http://dx.doi.org/10.1128/aem.00190-08.

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ABSTRACT Cellobiose utilization is a variable trait that is often used to differentiate members of the family Vibrionaceae. We investigated how Vibrio fischeri ES114 utilizes cellobiose and found a cluster of genes required for growth on this β-1,4-linked glucose disaccharide. This cluster includes genes annotated as a phosphotransferase system II (celA, celB, and celC), a glucokinase (celK), and a glucosidase (celG). Directly downstream of celCBGKA is celI, which encodes a LacI family regulator that represses cel transcription in the absence of cellobiose. When the celCBGKAI gene cluster was transferred to cellobiose-negative strains of Vibrio and Photobacterium, the cluster conferred the ability to utilize cellobiose. Genomic analyses of naturally cellobiose-positive Vibrio species revealed that V. salmonicida has a homolog of the celCBGKAI cluster, but V. vulnificus does not. Moreover, bioinformatic analyses revealed that CelG and CelK share the greatest homology with glucosidases and glucokinases in the phylum Firmicutes. These observations suggest that distinct genes for cellobiose utilization have been acquired by different lineages within the family Vibrionaceae. In addition, the loss of the celI regulator, but not the structural genes, attenuated the ability of V. fischeri to compete for colonization of its natural host, Euprymna scolopes, suggesting that repression of the cel gene cluster is important in this symbiosis. Finally, we show that the V. fischeri cellobioase (CelG) preferentially cleaves β-d-glucose linkages but also cleaves β-d-galactose-linked substrates such as 5-bromo-4-chloro-3-indolyl-β-d-galactoside (X-gal), a finding that has important implications for the use of lacZ as a marker or reporter gene in V. fischeri.
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47

Tsai, Li-Chu, Imamaddin Amiraslanov, Hung-Ren Chen, Yun-Wen Chen, Hsiao-Lin Lee, Po-Huang Liang, and Yen-Chywan Liaw. "Structures of exoglucanase from Clostridium cellulovorans: cellotetraose binding and cleavage." Acta Crystallographica Section F Structural Biology Communications 71, no. 10 (September 23, 2015): 1264–72. http://dx.doi.org/10.1107/s2053230x15015915.

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Exoglucanase/cellobiohydrolase (EC 3.2.1.176) hydrolyzes a β-1,4-glycosidic bond from the reducing end of cellulose and releases cellobiose as the major product. Three complex crystal structures of the glycosyl hydrolase 48 (GH48) cellobiohydrolase S (ExgS) from Clostridium cellulovorans with cellobiose, cellotetraose and triethylene glycol molecules were solved. The product cellobiose occupies subsites +1 and +2 in the open active-site cleft of the enzyme–cellotetraose complex structure, indicating an enzymatic hydrolysis function. Moreover, three triethylene glycol molecules and one pentaethylene glycol molecule are located at active-site subsites −2 to −6 in the structure of the ExgS–triethylene glycol complex shown here. Modelling of glucose into subsite −1 in the active site of the ExgS–cellobiose structure revealed that Glu50 acts as a proton donor and Asp222 plays a nucleophilic role.
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Song, Yan Lei, Yong Shui Qu, Chong Pin Huang, Li Hai Ge, Ying Xia Li, and Biao Hua Chen. "Single-Step Conversion of Cellobiose to 5-Hydroxymethylfurfural (5-HMF) Catalyzed by Poly Ionic Liquid." Advanced Materials Research 1004-1005 (August 2014): 885–90. http://dx.doi.org/10.4028/www.scientific.net/amr.1004-1005.885.

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The PIL which were prepared from imidazole and epichlorohydrin were used as catalysts for the conversion of cellobiose to 5-HMF. Effects of the catalyst anion, solvents, reaction temperature, and recycling time were investigated in detail. The optimum reaction conditions for conversion of cellobiose into 5-HMFcatalysed by [IMEP]BF4 were temperature 180 oC, cellobiose 0.5 g, and [IMEP]BF4 0.25 g in DMSO(30 mL). In this condition the yield of 5-HMF can reach 39.2% for 420min. The good positive correlation between the concentration of glucose and the formation rate of 5-HMF was given, and the conversion of glucose into 5-HMF is the key step of formation of 5-HMF from cellobiose. Moreover, [IMEP]BF4 has well cycle performance in the optimum reaction condition.
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Shiwa, Yuh, Haruko Fujiwara, Mao Numaguchi, Mohamed Ali Abdel-Rahman, Keisuke Nabeta, Yu Kanesaki, Yukihiro Tashiro, et al. "Transcriptome profile of carbon catabolite repression in an efficient l-(+)-lactic acid-producing bacterium Enterococcus mundtii QU25 grown in media with combinations of cellobiose, xylose, and glucose." PLOS ONE 15, no. 11 (November 17, 2020): e0242070. http://dx.doi.org/10.1371/journal.pone.0242070.

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Enterococcus mundtii QU25, a non-dairy lactic acid bacterium of the phylum Firmicutes, is capable of simultaneously fermenting cellobiose and xylose, and is described as a promising strain for the industrial production of optically pure l-lactic acid (≥ 99.9%) via homo-fermentation of lignocellulosic hydrolysates. Generally, Firmicutes bacteria show preferential consumption of sugar (usually glucose), termed carbon catabolite repression (CCR), while hampering the catabolism of other sugars. In our previous study, QU25 exhibited apparent CCR in a glucose-xylose mixture phenotypically, and transcriptional repression of the xylose operon encoding initial xylose metabolism genes, likely occurred in a CcpA-dependent manner. QU25 did not exhibit CCR phenotypically in a cellobiose-xylose mixture. The aim of the current study is to elucidate the transcriptional change associated with the simultaneous utilization of cellobiose and xylose. To this end, we performed RNA-seq analysis in the exponential growth phase of E. mundtii QU25 cells grown in glucose, cellobiose, and/or xylose as either sole or co-carbon sources. Our transcriptomic data showed that the xylose operon was weakly repressed in cells grown in a cellobiose-xylose mixture compared with that in cells grown in a glucose-xylose mixture. Furthermore, the gene expression of talC, the sole gene encoding transaldolase, is expected to be repressed by CcpA-mediated CCR. QU25 metabolized xylose without using transaldolase, which is necessary for homolactic fermentation from pentoses using the pentose-phosphate pathway. Hence, the metabolism of xylose in the presence of cellobiose by QU25 may have been due to 1) sufficient amounts of proteins encoded by the xylose operon genes for xylose metabolism despite of the slight repression of the operon, and 2) bypassing of the pentose-phosphate pathway without the TalC activity. Accordingly, we have determined the targets of genetic modification in QU25 to metabolize cellobiose, xylose and glucose simultaneously for application of the lactic fermentation from lignocellulosic hydrolysates.
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Ryu, Seunghyun, Julie Hipp, and Cong T. Trinh. "Activating and Elucidating Metabolism of Complex Sugars in Yarrowia lipolytica." Applied and Environmental Microbiology 82, no. 4 (December 18, 2015): 1334–45. http://dx.doi.org/10.1128/aem.03582-15.

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ABSTRACTThe oleaginous yeastYarrowia lipolyticais an industrially important host for production of organic acids, oleochemicals, lipids, and proteins with broad biotechnological applications. Albeit known for decades, the unique native metabolism ofY. lipolyticafor using complex fermentable sugars, which are abundant in lignocellulosic biomass, is poorly understood. In this study, we activated and elucidated the native sugar metabolism inY. lipolyticafor cell growth on xylose and cellobiose as well as their mixtures with glucose through comprehensive metabolic and transcriptomic analyses. We identified 7 putative glucose-specific transporters, 16 putative xylose-specific transporters, and 4 putative cellobiose-specific transporters that are transcriptionally upregulated for growth on respective single sugars.Y. lipolyticais capable of using xylose as a carbon source, but xylose dehydrogenase is the key bottleneck of xylose assimilation and is transcriptionally repressed by glucose.Y. lipolyticahas a set of 5 extracellular and 6 intracellular β-glucosidases and is capable of assimilating cellobiose via extra- and intracellular mechanisms, the latter being dominant for growth on cellobiose as a sole carbon source. Strikingly,Y. lipolyticaexhibited enhanced sugar utilization for growth in mixed sugars, with strong carbon catabolite activation for growth on the mixture of xylose and cellobiose and with mild carbon catabolite repression of glucose on xylose and cellobiose. The results of this study shed light on fundamental understanding of the complex native sugar metabolism ofY. lipolyticaand will help guide inverse metabolic engineering ofY. lipolyticafor enhanced conversion of biomass-derived fermentable sugars to chemicals and fuels.
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