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Journal articles on the topic 'Kineticі of sucrose hydrolysis'

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Published: 28 May 2022

Last updated: 29 May 2022

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1

Li, Dongmei, Chaofan Weng, Yi Ruan, Kan Li, Guoan Cai, Chenyao Song, and Qiang Lin. "An Optical Chiral Sensor Based on Weak Measurement for the Real-Time Monitoring of Sucrose Hydrolysis." Sensors 21, no. 3 (February 2, 2021): 1003. http://dx.doi.org/10.3390/s21031003.

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A chiral sensor with optical rotation detection based on weak measurement for the kinetic study of sucrose hydrolysis is presented. Based on the polarization modulation to the pre-selection state, the optical rotation of chiral sample was accurately determined through the central wavelength shift of the output spectrum. With this approach, the concentration response curves of sucrose and its hydrolysis products, i.e., fructose and glucose, were experimentally obtained for the hydrolysis analysis. By collecting the output spectrum with a frequency of 100 Hz and fitting the central wavelength shift synchronously during the measurement, the sucrose hydrolysis process was monitored in real time. Different hydrolysis conditions with varied concentration of invertase enzyme and citrate were implemented in this work. As a consequence, the real-time hydrolysis curves of the hydrolysis process with distinct velocities was achieved and analyzed. Such a kinetic monitoring about sucrose hydrolysis with optical rotation detection technology played a critical role in the researches involving sucrose, and also revealed the great potential of weak measurement in intersections, such as food safety inspection and chemical analysis.

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2

Hargono, Hargono, Bakti Jos, Abdullah Abdullah, and Teguh Riyanto. "Inhibition Effect of Ca2+ Ions on Sucrose Hydrolysis Using Invertase." Bulletin of Chemical Reaction Engineering & Catalysis 14, no. 3 (December 1, 2019): 646. http://dx.doi.org/10.9767/bcrec.14.3.4437.646-653.

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Fermentable sugar for bioethanol production can be produced from molasses due to its high sucrose content but Ca2+ ions found in the molasses may affect the hydrolysis. Therefore, this paper was focused to study the effect of Ca2+ ions as CaO on sucrose hydrolysis using invertase and to obtain the kinetic parameters. The kinetic parameters (KM and Vmax) were obtained using a Lineweaver-Burk plot. The value of KM and Vmax parameters were 36.181 g/L and 21.322 g/L.h, respectively. The Ca2+ ions act as competitive inhibitor in sucrose hydrolysis using invertase. Therefore, the inhibition mechanism was followed the competitive inhibition mechanism. The value of inhibition constant was 0.833 g/g. These parameters were obtained from the non-substrate inhibition process because this study used the low substrate concentrations which means the fermentable sugar production was low. Hence, there were still more challenges to studying the simultaneous effect of substrate and Ca2+ on sucrose hydrolysis to produce high fermentable sugar. Copyright © 2019 BCREC Group. All rights reserved

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3

Gao, Daming, Takashi Kobayashi, and Shuji Adachi. "Kinetics of Sucrose Hydrolysis in a Subcritical Water-ethanol Mixture." Journal of Applied Glycoscience 61, no. 1 (2014): 9–13. http://dx.doi.org/10.5458/jag.jag.jag-2013_006.

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4

Keramat, Ali, Ali Kargari, Morteza Sohrabi†, Hamed Mirshekar, and Hamidreza Sanaeepur. "Kinetic Model for Invertase-Induced Sucrose Hydrolysis: Initial Time Lag." Chemical Engineering & Technology 40, no. 3 (February 10, 2017): 529–36. http://dx.doi.org/10.1002/ceat.201400389.

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5

Abdullah, A., Hanapi Bin Mat, and W. Widayat. "Kinetic study of the utilisation of different substrates to lactic acid using Lactobacillus delbrueckii." Jurnal Teknik Kimia Indonesia 4, no. 1 (October 7, 2018): 153. http://dx.doi.org/10.5614/jtki.2005.4.1.4.

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AbstractLactic acid fermentation includes several reactions in association with the microorganism growth. A kinetic study was performed of the utilisation of multiple substrates to lactic acid using Lactobacillus delbrueckii. Batch fermentation was performed to study effect of different substrates such as glucose, fructose and sucrose. The objective of this research is to study kinetics grow microbial. An anaerobic fermentation were studied in 3 litres stirred fermentor (Biostat B Model) with working volume of 1 liter: temperature = 40ºC, pH=6.0, inoculums size= 5%, sugar concentration= 20 g/L. During the first hours of fermentation, glucose and fructose accumulated in the medium and the rate of hydrolysis of sucrose to glucose and fructose was faster than conversion of these substrate. The maximum concentration of glucose and fructose was 5.82 and 5.14 g/L respectively. The sucrose, glucose, and fructose consumption completely utilized at 56, 68, and 104 hours, respectively. Kinetic parameter for maximum specific growth rate in glucose, fructose and sucrose is 0.083, 0.024, and 0.024 (h-1), respectively. The saturation constant is 4.64, 3.41, and 1.36 g/L.Keywords: Kinetic Study, Sugars, Lactic Acid, Maximum Specific Growth Rate, Saturation Constant AbstrakFermentasi asam laktat melibatkan banyak reaksi dalam pertumbuhan mikroorganisme. Studi kinetika reaksi tentang kinerja penggunaan berbagai subtrat untuk memproduksi asam laktat dengan Lactobacillus delbrueckii.Subtrat yang digunakan adalah glukosa, fruktosa, dan sukrosa, dengan proses fermentasi curah. Penelitian ini bertujuan memepelajari kinetika pertumbuhan mikroba. Fermentasi anaerobik dilakukan dalam fermentor 3 liter (Biostat B Model) dengan volume total 1 liter, temperatur = 40ºC, pH= 6.0, konsentrasi inokulum = 5%, konsentrasi gula = 20 g/L. Selama satu jam pertama fermentasi, glukosa dan fruktosa diakumulasi dalam medium dan laju reaksi hidrolisis sukrosa menjadi glukosa dan fruktosa sangat cepat dibandingkan dengan konversi substrat ini. Konsentrasi glukosa dan fruktosa adalah 5.82 dan 5.14 g/L. Waktu yang dibutuhkan sukrosa, glukosa dan fruktosa masing-masing adalah 56, 68, dan 104 jam. Parameter kinetika untuk laju pertumbuhan spesifik maksimum dalam medium glukosa, fruktosa, dan sukrosa masing-masing adalah 0.083, 0.024, dan 0.024 (h-1). Konstanta saturasi adalah 4.64, 3.41, dan 1.36.Kata Kunci: Kinetika Reaksi, Gula, Asam Laktat, Laju Pertumbuhan Spesifik Maksimum, Konstanta Saturasi

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6

Hartofylax, V. H., C. E. Efstathiou, and T. P. Hadjiioannou. "Kinetic study of the acid hydrolysis of sucrose and lactose and kinetic determination of sucrose using a periodate-selective electrode." Analytica Chimica Acta 224 (1989): 159–68. http://dx.doi.org/10.1016/s0003-2670(00)86556-3.

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7

TORRES, A. PINHEIRO, F. A. R. OLIVEIRA, C. L. M. SILVA, and S. P. FORTUNA. "THE INFLUENCE of pH ON the KINETICS of ACID HYDROLYSIS of SUCROSE." Journal of Food Process Engineering 17, no. 2 (May 1994): 191–208. http://dx.doi.org/10.1111/j.1745-4530.1994.tb00335.x.

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8

Tang, Peng, Yetao Shu, Zhaoxin Wen, Yifei Song, Shuoqing Liu, Ting Wan, and Zhaoming Luo. "High-Resolution Determination of Kinetic Parameters of Sucrose Hydrolysis Based on Weak Measurement." IEEE Photonics Journal 14, no. 1 (February 2022): 1–6. http://dx.doi.org/10.1109/jphot.2022.3142072.

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9

Nathalie Jarroux, Marie-Jeanne Clément, Cedric Przybylski, Olek Maciejak, Patrick A. Curmi, and Hervé M. Cheradame. "Catalysis and specificity of the polycondensation of aminopropyltrimethoxysilane on nucleic acids." GSC Biological and Pharmaceutical Sciences 13, no. 2 (November 30, 2020): 290–99. http://dx.doi.org/10.30574/gscbps.2020.13.2.0332.

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The polycondensation of a silane derivative such as aminopropyltrimethoxysilane (ATMS) in the presence of nucleic acids has never been investigated. Our group has previously demonstrated that in chloroform ATMS hydrolysis and polycondensation were faster when the reaction were carried out in the presence of double stranded DNA (146 bp). The results showed that the kinetics of ATMS hydrolysis was affected by the base type used, a fast hydrolysis reaction rate being observed with nucleotide molecules containing adenosine group, and that in the absence of water the amino group of deoxyadenosine units, and not the hydroxylic group of the sucrose residue, can react with ATMS methoxy groups. The present work was initiated aiming at providing a better understanding of this effect. It was observed that the polymerization degree of oligodeoxyadenylate has a clear impact on the kinetic of reaction this effect being as much important as the polymerization degree of the oligodeoxyadenylate was high. Structural investigation by molecular modeling showed that this enhanced reactivity can be explained by conformational effects. Altogether, these results are accounted for assuming that DNA can act as a specific template for ATMS polycondensation, in organic medium such as chloroform, opening the way to possible DNA encapsulation, and a new way for DNA chemical modification in organic solvent.

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10

Hernandez, L., J. Arrieta, C. Menendez, R. Vazquez, A. Coego, V. Suarez, G. Selman, M. F. Petit-Glatron, and R. Chambert. "Isolation and enzymic properties of levansucrase secreted by Acetobacter diazotrophicus SRT4, a bacterium associated with sugar cane." Biochemical Journal 309, no. 1 (July 1, 1995): 113–18. http://dx.doi.org/10.1042/bj3090113.

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Acetobacter diazotrophicus, a nitrogen-fixing bacterium associated with sugar cane, secretes a levansucrase (sucrose-2,6-beta-D-fructan 6-beta-D-fructosyltransferase; EC 2.4.1.10). This enzyme is constitutively expressed and represents more than 70% of the total proteins secreted by strain SRT4. The purified protein consists of a single 58 kDa polypeptide with an isoelectric point of 5.5. Its activity is optimal at pH 5.0. It catalyses transfructosylation from sucrose to a variety of acceptors including water (sucrose hydrolysis), glucose (exchange reaction), fructan (polymerase reaction) and sucrose (oligofructoside synthesis). In vivo the polymerase activity leads to synthesis of a high-molecular-mass fructan of the levan type. A. diazotrophicus levansucrase catalyses transfructosylation via a Ping Pong mechanism involving the formation of a transient fructosyl-enzyme intermediate. The catalytic mechanism is very similar to that of Bacillus subtilis levansucrase. The kinetic parameters of the two enzymes are of the same order of magnitude. The main difference between the two enzyme specificities is the high yield of oligofructoside, particularly 1-kestotriose and kestotetraose, accumulated by A. diazotrophicus levansucrase during sucrose transformation. We discuss the hypothesis that these catalytic features may serve the different biological functions of each enzyme.

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11

Tombari, E., G. Salvetti, C. Ferrari, and G. P. Johari. "Kinetics and Thermodynamics of Sucrose Hydrolysis from Real-Time Enthalpy and Heat Capacity Measurements." Journal of Physical Chemistry B 111, no. 3 (January 2007): 496–501. http://dx.doi.org/10.1021/jp067061p.

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12

Famelart, Marie-Hélène. "Rennet coagulation of milk in the presence of sucrose." Journal of Dairy Research 61, no. 4 (November 1994): 473–83. http://dx.doi.org/10.1017/s0022029900028405.

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SummaryThe aim of this work was to test the diffusion-controlled hypothesis of milk coagulation kinetics by reducing the diffusion coefficient of casein micelles. This has been achieved by increasing the solvent viscosity of milk through sucrose addition. Milk was reconstituted from skim milk powder and sucrose added at 100–300 g kg–1. Hydrolysis and coagulation were followed by chromatographic determination of caseinomacropeptide content and optical, thermal and viscoelastic measurements. Soluble and ionic calcium were determined by atomic absorption spectrophotometry and ionometry and micelle size was measured by dynamic light scattering. Addition of sucrose resulted in a substantial retardation of both enzymic and aggregation steps, a re-equilibration of calcium because of water reduction, and a micelle size increase. The enzymic rate constant was inversely proportional to the viscosity, according to a diffusion-controlled model, and the lag or characteristic times for the aggregation reaction were inversely proportional to the viscosity. These results are consistent with the involvement of diffusion-controlled steps in the sequence of reactions.

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13

Goosen, Coenie, Xiao-Lian Yuan, Jolanda M. van Munster, Arthur F. J. Ram, Marc J. E. C. van der Maarel, and Lubbert Dijkhuizen. "Molecular and Biochemical Characterization of a Novel Intracellular Invertase from Aspergillus niger with Transfructosylating Activity." Eukaryotic Cell 6, no. 4 (February 9, 2007): 674–81. http://dx.doi.org/10.1128/ec.00361-06.

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ABSTRACT A novel subfamily of putative intracellular invertase enzymes (glycoside hydrolase family 32) has previously been identified in fungal genomes. Here, we report phylogenetic, molecular, and biochemical characteristics of SucB, one of two novel intracellular invertases identified in Aspergillus niger. The sucB gene was expressed in Escherichia coli and an invertase-negative strain of Saccharomyces cerevisiae. Enzyme purified from E. coli lysate displayed a molecular mass of 75 kDa, judging from sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis. Its optimum pH and temperature for sucrose hydrolysis were determined to be 5.0 and 37 to 40°C, respectively. In addition to sucrose, the enzyme hydrolyzed 1-kestose, nystose, and raffinose but not inulin and levan. SucB produced 1-kestose and nystose from sucrose and 1-kestose, respectively. With nystose as a substrate, products up to a degree of polymerization of 4 were observed. SucB displayed typical Michaelis-Menten kinetics with substrate inhibition on sucrose (apparent Km , Ki , and V max of 2.0 ± 0.2 mM, 268.1 ± 18.1 mM, and 6.6 ± 0.2 μmol min−1 mg−1 of protein [total activity], respectively). At sucrose concentrations up to 400 mM, transfructosylation (FTF) activity contributed approximately 20 to 30% to total activity. At higher sucrose concentrations, FTF activity increased to up to 50% of total activity. Disruption of sucB in A. niger resulted in an earlier onset of sporulation on solid medium containing various carbon sources, whereas no alteration of growth in liquid culture medium was observed. SucB thus does not play an essential role in inulin or sucrose catabolism in A. niger but may be needed for the intracellular conversion of sucrose to fructose, glucose, and small oligosaccharides.

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14

SONG, Donna D., and Nicholas A. JACQUES. "Mutation of aspartic acid residues in the fructosyltransferase of Streptococcus salivarius ATCC 25975." Biochemical Journal 344, no. 1 (November 8, 1999): 259–64. http://dx.doi.org/10.1042/bj3440259.

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The site-directed mutated fructosyltransferases (Ftfs) of Streptococcus salivarius ATCC 25975, D312E, D312S, D312N and D312K were all active at 37 °C, indicating that Asp-312 present in the ‘sucrose box’ was not the nucleophilic Asp residue responsible for the formation of a covalent fructosyl-enzyme intermediate required for enzyme activity. Analysis of the kinetic constants of the purified mutated forms of the enzyme showed that Asp-312 was most likely an essential amino acid involved in determining acceptor recognition and/or stabilizing a β-turn in the protein. In contrast, when the Asp-397 of the Ftf present in the conserved triplet RDP motif of all 60 bacterial and plant family-32 glycosylhydrolases was mutated to a Ser residue, both sucrose hydrolysis and polymerization ceased. Tryptophan emission spectra confirmed that this mutation did not alter protein structure. Comparison of published data from other site-directed mutated enzymes implicated the Asp residue in the RDP motif as the one that may form a transient covalent fructosyl intermediate during the catalysis of sucrose by the Ftf of S. salivarius.

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15

Heinzerling, Peter, Frank Schrader, and Sascha Schanze. "Measurement of Enzyme Kinetics by Use of a Blood Glucometer: Hydrolysis of Sucrose and Lactose." Journal of Chemical Education 89, no. 12 (October 2, 2012): 1582–86. http://dx.doi.org/10.1021/ed200735f.

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16

Rezaii, F., M. Danesh Mesgaran, and A. Heravi Moussavi. "The effect of non-structural carbohydrate on in vitro first order disappearance kinetic of cellulose." Proceedings of the British Society of Animal Science 2009 (April 2009): 177. http://dx.doi.org/10.1017/s1752756200030167.

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Ruminal cellulose digestion is a complex microbial process that involves adhesion of microbial cells to cellulose, cellulose hydrolysis, and fermentation of the resulting cellodextrins to volatile fatty acid, methane, and CO2 (Weimer, 1996). Information about how cellulose digestion and fermentation are affected by different ruminal environmental conditions is necessary to understand ruminant performance (Mourino, 2001). The aim of the present study was to elucidate the impact of type of supplemental non-structural carbohydrates (NSC) (starch and/or sucrose) on invitro first order disappearance kinetic of commercial cellulose (Cell).

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17

Prescott, M., A. D. Milne, and A. G. McLennan. "Characterization of the bis(5′-nucleosidyl) tetraphosphate pyrophosphohydrolase from encysted embryos of the brine shrimp Artemia." Biochemical Journal 259, no. 3 (May 1, 1989): 831–38. http://dx.doi.org/10.1042/bj2590831.

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The P1P4-bis(5′-nucleosidyl) tetraphosphate asymmetrical-pyrophosphohydrolase from encysted embryos of the brine shrimp Artemia has been purified over 11,000-fold to homogeneity. Anion-exchange chromatography resolves two major species with very similar properties. The enzyme is a single polypeptide of Mr 17,600 and is maximally active at pH 8.4 and 2 mM-Mg2+. It is inhibited by Ca2+ (IC50 = 0.9 mM with 2 mM-Mg2+) but not by Zn2+ ions. It preferentially hydrolyses P1P4-bis(5′-nucleosidyl) tetraphosphates, e.g. P1P4-bis(5′-adenosyl) tetraphosphate (Ap4A) (kcat. = 12.7 s-1; Km = 33 microM) and P1P4-bis(5′-guanosyl) tetraphosphate (Gp4G) (kcat. = 6.2 s-1; Km = 5 microM). With adenosine 5′-P1-tetraphospho-P4-5‴-guanosine (Ap4G) as substrate, there is a 4.5-fold preference for AMP and GTP as products and biphasic reaction kinetics are observed giving Km values of 4.7 microM and 34 microM, and corresponding rate constants of 6.5 s-1 and 11.9 s-1. The net rate constant for Ap4G hydrolysis is 7.6 s-1. The enzyme will also hydrolyse nucleotides with more than four phosphate groups, e.g. Ap5G, Ap6A and Gp5G are hydrolysed at 25%, 18% and 10% of the rate of Ap4A respectively. An NTP is always one of the products. Ap2A and Gp2G are not hydrolysed, while Ap3A and Gp3G are very poor substrates. When the enzyme is partially purified from embryos and larvae at different stages of development by sedimentation through a sucrose density gradient, its activity increases 3-fold during the first 12 h of pre-emergence development. This is followed by a slow decline during subsequent larval development. The similarity of this enzyme to other asymmetrical-pyrophosphohydrolases suggests that it did not evolve specifically to degrade the large yolk platelet store of Gp4G which is found in Artemia embryos, but that it probably serves the same general function in bis(5′-nucleosidyl) oligophosphate metabolism as in other cells.

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18

Soares, Ariana de Souza, Pedro Esteves Duarte Augusto, Bruno Ricardo de Castro Leite Júnior, Camila Archette Nogueira, Érica Nascif Rufino Vieira, Frederico Augusto Ribeiro de Barros, Paulo Cesar Stringheta, and Afonso Mota Ramos. "Ultrasound assisted enzymatic hydrolysis of sucrose catalyzed by invertase: Investigation on substrate, enzyme and kinetics parameters." LWT 107 (June 2019): 164–70. http://dx.doi.org/10.1016/j.lwt.2019.02.083.

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19

Shearwin, Keith E., and Donald J. Winzor. "Substrate as a source of thermodynamic nonideality in enzyme kinetic studies: Invertase-catalyzed hydrolysis of sucrose." Archives of Biochemistry and Biophysics 260, no. 2 (February 1988): 532–39. http://dx.doi.org/10.1016/0003-9861(88)90478-x.

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20

Helaleh, Murad I. H., and Eyad S. M. Abu-Nameh. "A Kinetic Approach for Determination of Cefadroxil in Pharmaceuticals by Alkaline Hydrolysis." Journal of AOAC INTERNATIONAL 81, no. 3 (May 1, 1998): 528–33. http://dx.doi.org/10.1093/jaoac/81.3.528.

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abstract A new, simple, and sensitive kinetic spectrophotometric method is described for analysis of cefadroxil by measurement of its absorbance at 470 nm after hydrolysis with NaOH at 80°C. Studies of the method's precision and accuracy gave a standard deviation of 0.44 μg/mL and a relative standard deviation of 1.93%. The method determines cefadroxil over the concentration range 10- 100 ug/mL. Calculated activation parameters were 12.42, 25.54, 26.25, and 69.00 Kcal/mole for AE*, AG*, Ahf, and AS*, respectively. Cefadroxil concentrations can be determined from the regression line equation y = 0.627x- 8.14 x 10"5, with a correlation coefficient of <1.0000. The method was validated by assay of cefadroxil in commercial capsules and tablets. Recoveries of common excipients were 99.6,100.00, 99.2, 99.6, and 100.4% for lactose, glucose, starch, sucrose, and fructose, respectively. Results were compared with those of a reference method. Calculated f and F values indicate no significant difference between the 2 methods. The degradation products of cefadroxil do not affect determination of cefadroxil.

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21

Chambert, R., and M. F. Petit-Glatron. "Polymerase and hydrolase activities of Bacillus subtilis levansucrase can be separately modulated by site-directed mutagenesis." Biochemical Journal 279, no. 1 (October 1, 1991): 35–41. http://dx.doi.org/10.1042/bj2790035.

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The levansucrase (sucrose:2,6-beta-D-fructan 6-beta-D-fructosyltransferase, EC 2.4.1.10) structural gene from a Bacillus subtilis mutant strain displaying a low polymerase activity was sequenced. Only one missense mutation changing Arg331 to His was responsible for this modified catalytic property. From this allele we created new mutations by directed mutagenesis, which modified the charge and polarity of site 331. Examination of the kinetics of the purified levansucrase variants revealed that transfructosylation activities are affected differently by the substitution chosen. His331→Arg completely restored the properties of the wild-type enzyme. The most striking feature of the other variants, namely Lys331, Ser331 and Leu331, was that they lost the ability of the wild-type enzyme to synthesize levan from sucrose alone. They were only capable of catalysing the first step of levan chain elongation, which is the formation of the trisaccharide ketose. The variant His331→Lys presented a higher kcat. for sucrose hydrolysis than the wild-type, and only this hydrolase activity was preserved in a solvent/water mixture in which the wild-type acted as a true polymerase. The two other substitutions reduced the efficiency of transfructosylation activities of the enzyme via the decrease of the rate of fructosyl-enzyme intermediate formation. For all variants, the sucrose affinity was slightly affected. This strong modulation of the enzyme specificities from a single amino acid substitution led us to postulate the hypothesis that bacterial levansucrases and plant fructosyltransferases involved in fructan synthesis may possess a common ancestral form.

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22

Adnadjevic, Borivoj K., and Jelena D. Jovanovic. "A comparative kinetics study on the isothermal heterogeneous acid-catalyzed hydrolysis of sucrose under conventional and microwave heating." Journal of Molecular Catalysis A: Chemical 356 (April 2012): 70–77. http://dx.doi.org/10.1016/j.molcata.2011.12.027.

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23

Kehlbeck, Joanne D., Clancy C. Slack, Marilyn T. Turnbull, and Susan J. Kohler. "Exploring the Hydrolysis of Sucrose by Invertase Using Nuclear Magnetic Resonance Spectroscopy: A Flexible Package of Kinetic Experiments." Journal of Chemical Education 91, no. 5 (April 3, 2014): 734–38. http://dx.doi.org/10.1021/ed300889s.

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24

Jackson, Alan A., J. Doherty, M. H. de Benoist, J. Hibbert, and C. Persaud. "The effect of the level of dietary protein, carbohydrate and fat on urea kinetics in young children during rapid catch-up weight gain." British Journal of Nutrition 64, no. 2 (September 1990): 371–85. http://dx.doi.org/10.1079/bjn19900039.

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The kinetics of urea metabolism were measured in children recovering from severe malnutrition. For a period of up to 10 d they received one of four diets which provided 711 kJ (170 kcal)/kg per d. Two groups received a diet with a high protein: energy (P:E) ratio of 10.6% (HP), enriched with either fat (HP/F) or maize starch and sucrose (HP/C). Two groups received a diet with a low P:E ratio of 8.8% (LP), enriched with either fat (LP/F) or maize starch and sucrose (LP/C). The rate of weight gain on the HP diets was significantly greater than on the LP diets. There was no difference in urea production between any of the four diets: HP/F 1.23 (SE 0.12), HP/C 1.37 (SE 0.14), LP/F 1.64 (SE 0.22), LP/C 1.15 (SE 0.15) mmol nitrogen/kg per h. On the HP diets urea excretion was 0.77 (SE 0.07) mmol N/kg per h. 61 % of production. There was significantly less urea excreted in the urine on diet LP/C than on LP/F (0.36 (SE 0.05) and 0.64 (SE 0.04) mmol N/kg per h respectively). A significantly greater percentage of the urea production was hydrolysed on the LP diets (61 %) compared with the HP diets (39 %), with the consequence that 50% of urea-N produced was available for synthetic activity on the LP diets compared with 30% on the HP diets. The increase in the urea hydrolysed on the LP diets was equivalent in magnitude to the decreased intake of N, so that overall intake plus hydrolysis did not differ between the LP and the HP diets. Crude N balance was similar on diets HP/F, HP/C and LP/C, but was significantly reduced on diet LP/F. These results show that there is an accommodation in urea kinetics during rapid catch-up weight gain, which becomes evident when the P:E ratio of the diet falls to 8.8%. It is proposed that, for a P:E ratio of 8.8%, protein is limiting for catch-up growth. When the intake has a P:E ratio of 8.8% the pattern of urea kinetics can be modified by the relative proportions of fat and carbohydrate in the diet. The measurement of urea kinetics provides a useful approach to the definition of the adequacy of the protein in the diet.

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25

Mandal, Urmila, Kaushik Das, and Kiron Kumar Kundu. "Kinetic solvent effects on acid-catalyzed hydrolysis of sucrose in aqueous mixtures of some protic, aprotic, and dipolar aprotic solvents." Canadian Journal of Chemistry 64, no. 8 (August 1, 1986): 1638–42. http://dx.doi.org/10.1139/v86-270.

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Rate constants of acid-catalyzed hydrolysis of sucrose (S) to D-glucose and L-fructose have been determined at 25 °C by optical rotation measurements in aqueous mixtures of protophobic protic glycerol (GL), protophilic protic urea (UH), aprotic dioxane (D), and dipolar aprotic dimethyl sulphoxide (DMSO). Transfer free energies of the substrate sucrose, [Formula: see text] have also been determined in the solvents from solubility measurements. These values as well as those of H+, as obtained earlier by use of the widely used tetraphenylarsonium tetraphenylboron (TATB) reference electrolyte assumption, yielded transfer free energies of the transition state. The observed log (ks/kw) – composition profiles reveal that the rates increase monotonically in GL–water mixtures, that decrease more or less monotonically in UH– and DMSO–water mixtures, and decrease up to 10 mol% D in D–water mixtures, beyond which the values tend to increase. Examination of [Formula: see text]–composition profiles for the different species in each case indicates that the initial and transition state solvation get more or less compensated and the observed rates are dictated by the increased solvation of H+ in aqueous UH, DMSO, and D co-solvent systems. But in GL–water mixtures the decreased solvation of the transition state compared with the initial state is overcome by the decreased solvation of H+, thus resulting in the gradual enhancement of the rates of the reaction. The observed linearity of the correlative plots of −δ(ΔG≠) [= RT ln (ks/kw)] vs. [Formula: see text] with distinctly different slopes in the two cases also substantiates the relative importance of H+ solvation in dictating the rates of the reaction in these widely different aqueous co-solvents.

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26

Taber, Ryan P., Chun Zhang, and Wei-Shou Hu. "Kinetics of Douglas-fir (Pseudotsuga menziesii) somatic embryo development." Canadian Journal of Botany 76, no. 5 (May 1, 1998): 863–71. http://dx.doi.org/10.1139/b98-050.

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Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) is one of the most economically important softwood species in the Pacific Northwest region. Somatic embryogenesis is a potential mass propagation technology for increasing the productivity of existing forest acreage. Combined with traditional breeding methods and recent advances of genetic engineering in plant species, somatic embryos can shorten the elite clone selection process significantly. Somatic embryo culture of Douglas-fir involves three stages: maintenance, abscisic acid (ABA) singulation, and maturation. At the beginning of all stages of culture, the population of cells with embryogenic potential is increased through the weekly subcultured maintenance stage; transfer into the ABA singulation stage initiates embryo development, while cotyledonary embryos are formed in the maturation state. The first two stages were carried out in submerged suspension culture, while during the maturation stage the developing embryos were placed on a polyester pad in a Petri dish. The growth kinetics in these stages were investigated. Fresh and dry weights were observed to double in the maintenance stage, while a smaller increase occurred in the ABA singulation stage. NH4+ was consumed preferentially to NO3- in all culture stages. Sucrose, the primary carbon source, was hydrolyzed to glucose and fructose rapidly. During cultivation, glucose and fructose were consumed simultaneously. The hydrolysis of sucrose resulted in a slight osmolarity increase at the beginning of all culture stages, while the subsequent consumption of glucose and fructose coincided with a gradual decrease in osmolarity. This dynamic osmolarity pressure profile is most profound in the maturation stage, in which the initial high osmotic pressure of 600 ± 20 mOsm/kg (mean ± SD) increased to 700 ± 27 mOsm/kg after sucrose was hydrolyzed but decreased to 350 ± 14 mOsm/kg after the depletion of sugars at the end of cultivation. The complete process of embryo development, from the week-long maintenance culture, through the weekly subcultured ABA singulation culture, to the maturation of embryos took between 70 and 80 days. Each millilitre of culture present at the onset of maintenance culture gave rise to approximately 420 mature embryos. During that same time period, the biomass increased approximately 100 times. Prolonging the cultivation time failed to increase the yield of mature embryos. These results give a more complete view of the kinetic behavior of developing Douglas-fir embryos and will aid in the optimization and scale-up of this important process.Key words: somatic embyrogenesis, Douglas-fir, Pseudotsuga menziesii, growth kinetics, ABA, osmolarity, development.

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Kwok, Kaho, Lisa J. Mauer, and Lynne S. Taylor. "Kinetics of Moisture-Induced Hydrolysis in Powder Blends Stored at and below the Deliquescence Relative Humidity: Investigation of Sucrose−Citric Acid Mixtures." Journal of Agricultural and Food Chemistry 58, no. 22 (November 24, 2010): 11716–24. http://dx.doi.org/10.1021/jf101941e.

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Chiu, Fan S., Shen H. Hsu, Jiun H. Chen, Yi Y. Hsiao, Yih J. Pan, Ru C. Van, Yun T. Huang, et al. "Differential response of vacuolar proton pumps to osmotica." Functional Plant Biology 33, no. 2 (2006): 195. http://dx.doi.org/10.1071/fp03248.

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The vacuole is a fundamental and dominant organelle and occupies a large part of the total cell volume in most mature plant cells. The higher-plant vacuole contains two types of proton-translocating pumps, H+-ATPase (EC 3.6.1.3) and H+-pyrophosphatase (EC 3.6.1.1), residing on the same membrane. These two enzymes generate roughly equal proton gradients across the vacuolar membrane for the secondary transport of ions and metabolites. However, the pumps respond differentially to stress in order to maintain critical functions of the vacuole. In this work, tonoplasts from etiolated mung bean seedlings (Vigna radiata L.) were used to investigate the function of these two enzymes under high osmotic pressure. At high concentrations of sucrose or sorbitol, the light scattering and volume of isolated vesicles were progressively changed. Concomitantly, enzymatic activities, proton translocation, and coupling efficiencies of these two proton-pumping enzymes were inhibited to various extents under high osmotic pressure. No significant change in enzymatic activities of purified vacuolar H+-PPase and H+-ATPase under similar conditions was observed. We thus believe that the membrane structure is an important determinant for proper function of proton pumping systems of plant vacuoles. Furthermore, kinetic analysis shows different variation in apparent Vmax but not in KM values of vacuolar H+-PPase and H+-ATPase at high osmolarity of sucrose and sorbitol, respectively, suggesting probable alterations in substrate hydrolysis reactions but not substrate-binding affinity of the enzymes. A working model is proposed to interpret supplemental roles of vacuolar H+-PPase and H+-ATPase to maintain appropriate functions of plant tonoplasts.

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Schwarz, Alexandra, Lothar Brecker, and Bernd Nidetzky. "Acid–base catalysis in Leuconostoc mesenteroides sucrose phosphorylase probed by site-directed mutagenesis and detailed kinetic comparison of wild-type and Glu237→Gln mutant enzymes." Biochemical Journal 403, no. 3 (April 12, 2007): 441–49. http://dx.doi.org/10.1042/bj20070042.

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The role of acid–base catalysis in the two-step enzymatic mechanism of α-retaining glucosyl transfer by Leuconostoc mesenteroides sucrose phosphorylase has been examined through site-directed replacement of the putative catalytic Glu237 and detailed comparison of purified wild-type and Glu237→Gln mutant enzymes using steady-state kinetics. Reactions with substrates requiring Brønsted catalytic assistance for glucosylation or deglucosylation were selectively slowed at the respective step, about 105-fold, in E237Q. Azide, acetate and formate but not halides restored catalytic activity up to 300-fold in E237Q under conditions in which the deglucosylation step was rate-determining, and promoted production of the corresponding α-glucosides. In situ proton NMR studies of the chemical rescue of E237Q by acetate and formate revealed that enzymatically formed α-glucose 1-esters decomposed spontaneously via acyl group migration and hydrolysis. Using pH profiles of kcat/Km, the pH dependences of kinetically isolated glucosylation and deglucosylation steps were analysed for wild-type and E237Q. Glucosylation of the wild-type proceeded optimally above and below apparent pKa values of about 5.6 and 7.2 respectively whereas deglucosylation was dependent on the apparent single ionization of a group of pKa≈5.8 that must be deprotonated for reaction. Glucosylation of E237Q was slowed below apparent pKa≈6.0 but had lost the high pH dependence of the wild-type. Deglucosylation of E237Q was pH-independent. The results allow unequivocal assignment of Glu237 as the catalytic acid–base of sucrose phosphorylase. They support a mechanism in which the pKa of Glu237 cycles between ≈7.2 in free enzyme and ≈5.8 in glucosyl enzyme intermediate, ensuring optimal participation of the glutamate residue side chain at each step in catalysis. Enzyme deglucosylation to an anionic nucleophile took place with Glu237 protonated or unprotonated. The results delineate how conserved active-site groups of retaining glycoside hydrolases can accommodate enzymatic function of a phosphorylase.

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Sampedro, José G., Rosario A. Muñoz-Clares, and Salvador Uribe. "Trehalose-Mediated Inhibition of the Plasma Membrane H+-ATPase from Kluyveromyces lactis: Dependence on Viscosity and Temperature." Journal of Bacteriology 184, no. 16 (August 15, 2002): 4384–91. http://dx.doi.org/10.1128/jb.184.16.4384-4391.2002.

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ABSTRACT The effect of increasing trehalose concentrations on the kinetics of the plasma membrane H+-ATPase from Kluyveromyces lactis was studied at different temperatures. At 20°C, increasing concentrations of trehalose (0.2 to 0.8 M) decreased V max and increased S 0.5 (substrate concentration when initial velocity equals 0.5 V max), mainly at high trehalose concentrations (0.6 to 0.8 M). The quotient V max/S 0.5 decreased from 5.76 μmol of ATP mg of protein−1 min−1 mM−1 in the absence of trehalose to 1.63 μmol of ATP mg of protein−1 min−1 mM−1 in the presence of 0.8 M trehalose. The decrease in V max was linearly dependent on solution viscosity (η), suggesting that inhibition was due to hindering of protein domain diffusional motion during catalysis and in accordance with Kramer's theory for reactions in solution. In this regard, two other viscosity-increasing agents, sucrose and glycerol, behaved similarly, exhibiting the same viscosity-enzyme inhibition correlation predicted. In the absence of trehalose, increasing the temperature up to 40°C resulted in an exponential increase in V max and a decrease in enzyme cooperativity (n), while S 0.5 was not modified. As temperature increased, the effect of trehalose on V max decreased to become negligible at 40°C, in good correlation with the temperature-mediated decrease in viscosity. The trehalose-mediated increase in S 0.5 was similar at all temperatures tested, and thus, trehalose effects on V max/S 0.5 were always observed. Trehalose increased the activation energy for ATP hydrolysis. Trehalose-mediated inhibition of enzymes may explain why yeast rapidly hydrolyzes trehalose when exiting heat shock.

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Darvish, A., and P. J. Metting. "Purification and regulation of an AMP-specific cytosolic 5'-nucleotidase from dog heart." American Journal of Physiology-Heart and Circulatory Physiology 264, no. 5 (May 1, 1993): H1528—H1534. http://dx.doi.org/10.1152/ajpheart.1993.264.5.h1528.

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The major enzyme responsible for adenosine production during myocardial hypoxia or ischemia is 5'-nucleotidase. We purified an AMP-specific 5'-nucleotidase to homogeneity from the 150,000-g supernatant of dog heart homogenate using phosphocellulose, DEAE-cellulose, and ADP-agarose affinity chromatography. Sodium dodecyl sulfate-poly-acrylamide gel electrophoresis of the purified enzyme yielded a single protein band of 43 kDa. The molecular mass of the holoenzyme, determined by gel filtration and sucrose density-gradient centrifugation, was approximately 166 kDa, suggesting a tetrameric structure. Dog heart cytosolic 5'-nucleotidase was active at physiological pH (6.8-7.8) and demonstrated a preference for AMP over IMP as substrate. The enzyme exhibited sigmoidal saturation kinetics, with half-maximal activity at 2.6 mM AMP in the absence of ADP. ADP (0-250 microM) activated cytosolic 5'-nucleotidase by increasing maximal velocity and affinity for AMP. The enzyme was inhibited by 4 mM ATP, but 5'-nucleotidase activity increased as [ATP] was reduced. Mg2+ was required for activity, with maximal activation at approximately 3.5 mM free Mg2+. These data suggest that the regulation of AMP-specific cytosolic 5'-nucleotidase by adenine nucleotides and free Mg2+ may be important in the production of adenosine during conditions promoting ATP hydrolysis, such as myocardial hypoxia or ischemia.

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Dutta, Jayati Ray, and Rintu Banerjee. "Isolation and characterization of a newly isolated Pseudomonas mutant for protease production." Brazilian Archives of Biology and Technology 49, no. 1 (January 2006): 37–47. http://dx.doi.org/10.1590/s1516-89132006000100005.

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A potent bacterium for extracellular protease production was isolated from local soil and identified as Pseudomonas sp. RAJR 044. A mutant of this strain JNGR 242 with protease productivity 2.5 fold higher was obtained by ultraviolet irradiation under experimentally optimized conditions of pH 7.0, temperature of 34ºC, inoculum volume of 1.0 mL and incubation time of 24 hours. Comparative analysis of the chemical characteristics i.e. assimilation of carbon and nitrogen sources were also carried out. Maximum growth of the mutant strain in 2% gelatin agar plate was obtained in presence of dextrose (2%), maltose (2%), ammonium sulfate (2%) and potassium nitrate (2%) whereas, that of the parent strain was found in sucrose (2%) and ammonium nitrate (2%). The purified proteases from both the strains (parent and mutant) appeared as single homogeneous bands corresponding to 14.4 kDa molecular weight on SDS-PAGE. On studying the kinetic properties of both strains it was observed that the rate of casein hydrolysis was maximum at pH 8.0 and 7.0 and temperatures 45º C and 60º C for the parent and mutant strains respectively. It was also observed that both the extracellular proteases were inhibited by a serine protease inhibitor i.e. PMSF at 2mM concentration.

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33

Huang, Yung-Cheng, Shu-Meng Hsu, Feng-Shiun Shie, Young-Ji Shiao, Li-Jung Chao, Hui-Wen Chen, Heng-Hsiang Yao, Meng An Chien, Chung-Chih Lin, and Huey-Jen Tsay. "Reduced mitochondria membrane potential and lysosomal acidification are associated with decreased oligomeric Aβ degradation induced by hyperglycemia: A study of mixed glia cultures." PLOS ONE 17, no. 1 (January 24, 2022): e0260966. http://dx.doi.org/10.1371/journal.pone.0260966.

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Diabetes is a risk factor for Alzheimer’s disease (AD), a chronic neurodegenerative disease. We and others have shown prediabetes, including hyperglycemia and obesity induced by high fat and high sucrose diets, is associated with exacerbated amyloid beta (Aβ) accumulation and cognitive impairment in AD transgenic mice. However, whether hyperglycemia reduce glial clearance of oligomeric amyloid-β (oAβ), the most neurotoxic Aβ aggregate, remains unclear. Mixed glial cultures simulating the coexistence of astrocytes and microglia in the neural microenvironment were established to investigate glial clearance of oAβ under normoglycemia and chronic hyperglycemia. Ramified microglia and low IL-1β release were observed in mixed glia cultures. In contrast, amoeboid-like microglia and higher IL-1β release were observed in primary microglia cultures. APPswe/PS1dE9 transgenic mice are a commonly used AD mouse model. Microglia close to senile plaques in APPswe/PS1dE9 transgenic mice exposed to normoglycemia or chronic hyperglycemia exhibited an amoeboid-like morphology; other microglia were ramified. Therefore, mixed glia cultures reproduce the in vivo ramified microglial morphology. To investigate the impact of sustained high-glucose conditions on glial oAβ clearance, mixed glia were cultured in media containing 5.5 mM glucose (normal glucose, NG) or 25 mM glucose (high glucose, HG) for 16 days. Compared to NG, HG reduced the steady-state level of oAβ puncta internalized by microglia and astrocytes and decreased oAβ degradation kinetics. Furthermore, the lysosomal acidification and lysosomal hydrolysis activity of microglia and astrocytes were lower in HG with and without oAβ treatment than NG. Moreover, HG reduced mitochondrial membrane potential and ATP levels in mixed glia, which can lead to reduced lysosomal function. Overall, continuous high glucose reduces microglial and astrocytic ATP production and lysosome activity which may lead to decreased glial oAβ degradation. Our study reveals diabetes-induced hyperglycemia hinders glial oAβ clearance and contributes to oAβ accumulation in AD pathogenesis.

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34

Gasset, M., A. Martinez del Pozo, M. Oñaderra, and J. G. Gavilanes. "Study of the interaction between the antitumour protein α-sarcin and phospholipid vesicles." Biochemical Journal 258, no. 2 (March 1, 1989): 569–75. http://dx.doi.org/10.1042/bj2580569.

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alpha-Sarcin is a single polypeptide chain protein which exhibits antitumour activity by degrading the larger ribosomal RNA of tumour cells. We describe the interaction of a alpha-sarcin with lipid model systems. The protein specifically interacts with negatively-charged phospholipid vesicles, resulting in protein-lipid complexes which can be isolated by ultracentrifugation in a sucrose gradient. alpha-Sarcin causes aggregation of such vesicles. The extent of this interaction progressively decreases when the molar ratio of phosphatidylcholine increases in acidic vesicles. The kinetics of the vesicle aggregation induced by the protein have been measured. This process is dependent on the ratio of alpha-sarcin present in the protein-lipid system. A saturation plot is observed from phospholipid vesicles-protein titrations. The saturating protein/lipid molar ratio is 1:50. The effect produced by the antitumour protein on the lipid vesicles is dependent on neither the length nor the degree of unsaturation of the phospholipid acyl chain. However, the aggregation is dependent on temperature, being many times higher above the phase transition temperature of the corresponding phospholipid than below it. The effects of pH and ionic strength have also been considered. An increase in the ionic strength does not abolish the protein-lipid interaction. The effect of pH may be related to conformational changes of the protein. Binding experiments reveal a strong interaction between alpha-sarcin and acidic vesicles, with Kd = 0.06 microM. The peptide bonds of the protein are protected against trypsin hydrolysis upon binding to acidic vesicles. The interaction of the protein with phosphatidylglycerol vesicles does not modify the phase transition temperature of the lipid, although it decreases the amplitude of the change of fluorescence anisotropy associated to the co-operative melting of 1,6-diphenyl-1,3,5-hexatriene (DPH)-labelled vesicles. The results are interpreted in terms of the existence of both electrostatic and hydrophobic components for the interaction between phospholipid vesicles and the antitumour protein.

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Goldberg, R. N., Y. B. Tewari, and J. C. Ahluwalia. "Thermodynamics of the hydrolysis of sucrose." Journal of Biological Chemistry 264, no. 17 (June 1989): 9901–4. http://dx.doi.org/10.1016/s0021-9258(18)81744-6.

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36

Nagamune, Teruyuki, Takashi Nakamura, Isao Endo, and Ichiro Inoue. "Simulation of Sucrose Hydrolysis by Yeast." KAGAKU KOGAKU RONBUNSHU 17, no. 3 (1991): 462–69. http://dx.doi.org/10.1252/kakoronbunshu.17.462.

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37

Iloukhani, H., S. Azizian, and N. Samadani. "Hydrolysis of Sucrose by Heterogeneous Catalysis." Physics and Chemistry of Liquids 40, no. 2 (January 2002): 159–65. http://dx.doi.org/10.1080/00319100208086658.

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38

Pito, D. S., I. M. Fonseca, A. M. Ramos, J. Vital, and J. E. Castanheiro. "Hydrolysis of sucrose over composite catalysts." Chemical Engineering Journal 184 (March 2012): 347–51. http://dx.doi.org/10.1016/j.cej.2012.01.033.

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39

Catana, R., B. S. Ferreira, J. M. S. Cabral, and P. Fernandes. "Immobilization of inulinase for sucrose hydrolysis." Food Chemistry 91, no. 3 (July 2005): 517–20. http://dx.doi.org/10.1016/j.foodchem.2004.04.041.

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40

Romanov, Vasilly I., and Esperanza Martínez-Romero. "Sucrose transport and hydrolysis inRhizobium tropici." Plant and Soil 161, no. 1 (April 1994): 91–96. http://dx.doi.org/10.1007/bf02183088.

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41

Туровская, Светлана Николаевна. "The synthesis of galactooligosaccharides is a promising direction of the bioconversion of lactose-containing milk systems." Food processing industry, no. 3 (March 5, 2022): 15–19. http://dx.doi.org/10.52653/ppi.2022.3.3.004.

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Галактоолигосахариды (ГОС) - производные молочного сахара, образуемые в процессе гидролиза в побочной реакции, называемой трансгликозилированием, которая в молочных системах с концентрацией лактозы более 10 % превалирует над гидролизом. ГОС относят к классу растворимых неперевариваемых олигосахаридов, включающих от 2 до 7 и более остатков галактозы, соединенных с остатком глюкозы. В настоящее время благодаря исследованиям структур, свойств, способов синтеза ГОС получены новые знания об их функциональных и технологических свойствах. Доказано, что они обладают пребиотической и иммуностимулирующей активностью, положительно воздействуют на всасывание минеральных веществ, улучшают деятельность печени и пр. Также ГОС устойчивы к температурным воздействиям, характеризуются меньшей по отношению к сахарозе сладостью, являются гигроскопичными веществами, влияют на активность воды, точку замерзания и вязкость продуктов. Кроме синтеза ГОС в процессе трансгликозилирования непосредственно в молочных системах, их промышленно получают из вторичного лактозосодержащего сырья, в основном ферментативным способом, основанным на реакции трансгалактозилирования, катализируемой бета-галактозидазами, наиболее изученными продуцентами которой являются Aspergillus oryzae, Kluyveromyces lactis и Bacillus circulans. Применительно к молочным консервам гидролитическая способность бета-галактозидазы давно используется для снижения содержания лактозы в молоке (до или после сгущения), исключая тем самым из технологического процесса стадию кристаллизации и сокращая продолжительность термообработки за счет интенсификации реакции Майяра (при производстве вареного сгущенного молока с сахаром). При этом не уделялось должного внимания реакции трансгалактозилирования. В статье проанализированы и систематизированы результаты исследований увеличения естественного содержания ГОС в различных молочных системах при внесении в них бета-галактозидазы и происходящей при этом кинетике биоконверсии. Оценивая возможность синтеза ГОС непосредственно в лактозосодержащем сырье путем биоконверсии, представляется весьма перспективным не только разработка продуктов функциональной направленности, но и нивелирование различных негативных факторов в процессе производства и хранения консервированной молочной продукции. Galactooligosaccharides (GOS) are derivatives of lactose, products of hydrolysis’s side reaction - transglycosylation, which prevails over hydrolysis in milk systems with lactose concentration more than 10%. GOS is defined as a class of soluble non-digestible oligosaccharides, containing 2-7 or more galactose residues bonded to a glucose residue. According to the studies of the structures, properties and synthesis methods of GOS, new knowledge about their functional and technological properties has been obtained nowadays. GOS’s prebiotic and immunostimulating activity, positive effect on the absorption of minerals, improving liver function, etc. were proved. Furthermore, it’s known that GOS are heat-resistant, hygroscopic substances; they are less sweet than sucrose and influence the activity of water, freezing point and products’ viscosity. Apart from the transglycosylation’s direct synthesis of GOS in milk systems, they are industrially produced from secondary lactose-containing raw materials mainly through catalytic transgalactosylation with beta-galactosidases, which most studied producers are Aspergillus oryzae, Kluyveromyces lactis and Bacillus circulans. For canned milk products, the hydrolytic ability of beta-galactosidase has long been used to reduce the lactose content in milk (before or after evaporation). This step excludes the crystallization stage from the technological process and reduces the duration of heat treatment by intensifying the Maillard reaction in case of condensed sweetened cooked milk. However, it is worthy of note that works specifically focused on transgalactosylation reaction are few in number. The paper aims to analyze and systematize the results of studies on the increase of the natural GOS content in various milk systems using beta-galactosidase and to review the resulting bioconversion kinetics. Assessing the possibility of direct GOS synthesis in lactose-containing raw materials by bioconversion, not only the development of functional products, but also the levelling of various negative factors in the production and storage of preserved dairy products seems very promising.

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Schebor, Carolina, Maria del Pilar Buera, Jorge Chirife, and Marcus Karel. "Sucrose hydrolysis in a glassy starch matrix." LWT - Food Science and Technology 28, no. 2 (January 1995): 245–48. http://dx.doi.org/10.1016/s0023-6438(95)91684-9.

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Druart, Ph, and O. De Wulf. "Activated charcoal catalyses sucrose hydrolysis during autoclaving." Plant Cell, Tissue and Organ Culture 32, no. 1 (January 1993): 97–99. http://dx.doi.org/10.1007/bf00040122.

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Buttersack, Christoph, and Daniela Laketic. "Hydrolysis of sucrose by dealuminated Y-zeolites." Journal of Molecular Catalysis 94, no. 3 (December 1994): L283—L290. http://dx.doi.org/10.1016/0304-5102(94)00158-8.

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45

Buttersack, Christoph, Jörg Hofmann, and Roger Gläser. "Hydrolysis of Sucrose over Sulfonic Acid Resins." ChemCatChem 13, no. 15 (July 9, 2021): 3443–60. http://dx.doi.org/10.1002/cctc.202100457.

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46

Jones, B. J. M., B. E. Higgins, and D. B. A. Silk. "Glucose absorption from maltotriose and glucose oligomers in the human jejunum." Clinical Science 72, no. 4 (April 1, 1987): 409–14. http://dx.doi.org/10.1042/cs0720409.

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1. The jejunal absorption of glucose from (1–4)-linked glucose oligomers including maltotriose has been compared with that from free glucose and sucrose in normal subjects. 2. A steady-state perfusion technique in vivo was used to study proximal jejunal assimilation of isotonic sugar-saline solutions isocaloric with 140 mmol/l glucose. Endogenous α-amylase was excluded from the test segment by proximal balloon occlusion. The glucose oligomer mixture consisted mainly of maltotriose, maltotetraose, maltopentaose and maltoheptaose. 3. Glucose absorption was significantly faster from maltotriose alone and from the glucose oligomer mixture than from 140 mmol/l glucose controls, whereas glucose absorption from 70 mmol/l sucrose was similar to that from 70 mmol/l glucose plus 70 mmol/l fructose. 4. Hydrolysis in vivo of maltotriose, the oligomer mixture and sucrose were similar, indicating that capture of glucose released by brush border sucrose hydrolysis was less efficient than that associated with (1–4)-linked oligomer hydrolysis. This suggests that the stoichiometric relationship of the active hydrolysis sites for sucrose to the glucose transport system is less advantageous than that of active sites for maltose hydrolysis. 5. Hydrolysis of oligomers larger than maltohexaose may be rate limiting for glucose absorption in the absence of luminal amylase activity.

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47

Williamson, P. R., M. A. Huber, and J. E. Bennett. "Role of maltase in the utilization of sucrose by Candida albicans." Biochemical Journal 291, no. 3 (May 1, 1993): 765–71. http://dx.doi.org/10.1042/bj2910765.

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Two isoenzymes of maltase (EC 3.2.1.20) were purified to homogeneity from Candida albicans. Isoenzymes I and II were found to have apparent molecular masses of 63 and 66 kDa on SDS/PAGE with isoelectric points of 5.0 and 4.6 respectively. Both isoenzymes resembled each other in similar N-terminal sequence, specificity for the alpha(1-−>4) glycosidic linkage and immune cross-reactivity on Western blots using a maltase II antigen-purified rabbit antibody. Maltase was induced by growth on sucrose whereas beta-fructofuranosidase activity could not be detected under similar conditions. Maltase I and II were shown to be unglycosylated enzymes by neutral sugar assay, and more than 90% of alpha-glucosidase activity was recoverable from spheroplasts. These data, in combination with other results from this laboratory [Geber, Williamson, Rex, Sweeney and Bennett (1992) J. Bacteriol. 174, 6992-6996] showing lack of a plausible leader sequence in genomic or mRNA transcripts, suggest an intracellular localization of the enzyme. To establish further the mechanism of sucrose assimilation by maltase, the existence of a sucrose-inducible H+/sucrose syn-transporter was demonstrated by (1) the kinetics of sucrose-induced [14C]sucrose uptake, (2) recovery of intact [14C]sucrose from ground cells by t.l.c. and (3) transport of 0.83 mol of H+/mol of [14C]sucrose. In total, the above is consistent with a mechanism whereby sucrose is transported into C. albicans to be hydrolysed by an intracellular maltase.

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48

Rébeillé, F., R. Bligny, J. B. Martin, and R. Douce. "Effect of sucrose starvation on sycamore (Acer pseudoplatanus) cell carbohydrate and Pi status." Biochemical Journal 226, no. 3 (March 15, 1985): 679–84. http://dx.doi.org/10.1042/bj2260679.

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The mobilization of stored carbohydrates during sucrose starvation was studied with sycamore (Acer pseudoplatanus) cells. When sucrose was omitted from the nutrient medium, the intracellular sucrose pool decreased rapidly during the first hours of the experiment, whereas the starch content remained practically unchanged. After 10h of sucrose starvation, starch hydrolysis replaced sucrose breakdown. From this moment, the phosphate-ester pool and respiration rate decreased with time. Conversely, the intracellular Pi concentration increased. 31P n.m.r. of intact sycamore cells indicated that, under these conditions, most of the Pi accumulated in the vacuole. These results strongly suggest that starch breakdown, in contrast with sucrose hydrolysis, is not rapid enough to maintain a high cellular metabolism.

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Echeverria, Ed. "Acid invertase (sucrose hydrolysis) is not required for sucrose mobilization from the vacuole." Physiologia Plantarum 104, no. 1 (September 1998): 17–21. http://dx.doi.org/10.1034/j.1399-3054.1998.1040103.x.

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A. Mahmood, Waleed. "HYDROLYSIS OF SUCROSE BY IMMOBILIZED Saccharomyces cerevisiae INVERTASE." Mesopotamia Journal of Agriculture 38, no. 1 (June 28, 2010): 2–11. http://dx.doi.org/10.33899/magrj.2010.27739.

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