Abstract
Cells of Lactobacillus bulgaricus, Escherichia coli, and Kluyveromyces (Saccharomyces) lactis immobilized in polyacrylamide gel beads retained 27 to 61% of the beta-galactosidase activity of intact cells. Optimum temperature and pH and thermostability of these microbial beta-galactosidases were negligibly affected by the immobilization. Km values of beta-galactosidase in immobilized cells of L. bulgaricus, E. coli, and K. lactis toward lactose were 4.2, 5.4, and 30 mM, respectively. Neither inhibition nor activation of beta-galactosidase in immobilized L. bulgaricus and E. coli appeared in the presence of galactose, but remarkable inhibition by galactose was detected in the case of the enzyme of immobilized K. lactis. Glucose inhibited noncompetitively the activity of three species of immobilized microbial cells. These kinetic properties were almost the same as those of free beta-galactosidase extracted from individual microorganisms. The activity of immobilized K. lactis was fairly stable during repeated runs, but those of E. coli and L. bulgaricus decreased gradually. These immobilized microbial cells, when introduced into skim milk, demonstrated high activity for converting lactose to monosaccharides. The flavor of skim milk was hardly affected by treatment with these immobilized cells, although the degree of sweetness was raised considerably.
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- ARONSON M. Transgalactosidation during lactose hydrolysis. Arch Biochem Biophys. 1952 Aug;39(2):370–378. doi: 10.1016/0003-9861(52)90346-9. [DOI] [PubMed] [Google Scholar]
- BURSTEIN C., COHN M., KEPES A., MONOD J. R OLE DU LACTOSE ET DE SES PRODUITS M'ETABOLIQUES DANS L'INDUCTION DE L'OP'ERON LACTOSE CHEZ ESCHERICHIA COLI. Biochim Biophys Acta. 1965 Apr 19;95:634–639. [PubMed] [Google Scholar]
- Chibata I., Tosa T., Sato T. Immobilized aspartase-containing microbial cells: preparation and enzymatic properties. Appl Microbiol. 1974 May;27(5):878–885. doi: 10.1128/am.27.5.878-885.1974. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cornish-Bowden A. A simple graphical method for determining the inhibition constants of mixed, uncompetitive and non-competitive inhibitors. Biochem J. 1974 Jan;137(1):143–144. doi: 10.1042/bj1370143. [DOI] [PMC free article] [PubMed] [Google Scholar]
- DIXON M. The determination of enzyme inhibitor constants. Biochem J. 1953 Aug;55(1):170–171. doi: 10.1042/bj0550170. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lee Y. C., Wacek V. Galactosidases from Aspergillus niger. Arch Biochem Biophys. 1970 May;138(1):264–271. doi: 10.1016/0003-9861(70)90307-3. [DOI] [PubMed] [Google Scholar]
- Martin C. K., Perlman D. Conversion of L-sorbose to L-sorbosone by immobilized cells of Gluconobacter melanogenus IFO 3293. Biotechnol Bioeng. 1976 Feb;18(2):217–237. doi: 10.1002/bit.260180208. [DOI] [PubMed] [Google Scholar]
- Mori T., Sato T., Tosa T., Chibata I. Studies on immobilized enzymes. X. Preparation and properties of aminoacylase entrapped into acrylamide gel-lattice. Enzymologia. 1972 Oct 31;43(4):213–226. [PubMed] [Google Scholar]
- Mori T., Tosa T., Chibata I. Preparation and properties of asparaginase entrapped in the lattice of polyacrylamide gel. Cancer Res. 1974 Nov;34(11):3066–3068. [PubMed] [Google Scholar]
- Morris D. L. Quantitative Determination of Carbohydrates With Dreywood's Anthrone Reagent. Science. 1948 Mar 5;107(2775):254–255. doi: 10.1126/science.107.2775.254. [DOI] [PubMed] [Google Scholar]
- Ohmiya K., Sato Y. Purification and Properties of Intracellular Proteinase from Streptococcus cremoris. Appl Microbiol. 1975 Nov;30(5):738–745. doi: 10.1128/am.30.5.738-745.1975. [DOI] [PMC free article] [PubMed] [Google Scholar]
- PRIDHAM J. B., WALLENFELS K. ENZYMATIC GALACTOSYLATION AND FUCOSYLATION OF PHENOLS. Nature. 1964 May 2;202:488–489. doi: 10.1038/202488a0. [DOI] [PubMed] [Google Scholar]
- Srere P. A., Mattiasson B., Mosbach K. An immobilized three-enzyme system: a model for microenvironmental compartmentation in mitochondria. Proc Natl Acad Sci U S A. 1973 Sep;70(9):2534–2538. doi: 10.1073/pnas.70.9.2534. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Vieth W. R., Wang S. S., Saini R. Immobilization of whole cells in a membraneous form. Biotechnol Bioeng. 1973 May;15(3):565–569. doi: 10.1002/bit.260150312. [DOI] [PubMed] [Google Scholar]
- Woychik J. H., Wondolowski M. V. Covalent bonding of fungal -galactosidase to glass. Biochim Biophys Acta. 1972 Dec 7;289(2):347–351. doi: 10.1016/0005-2744(72)90085-x. [DOI] [PubMed] [Google Scholar]