Regulation and genetic enhancement of glucoamylase and pullulanase production in Clostridium thermohydrosulfuricum
- 1 December 1985
- journal article
- research article
- Published by American Society for Microbiology in Journal of Bacteriology
- Vol. 164 (3), 1146-1152
- https://doi.org/10.1128/jb.164.3.1146-1152.1985
Abstract
We studied the general mechanism for regulation of glucoamylase and pullulanase synthesis in Clostridium thermohydrosulfuricum. These amylases were expressed only when the organism was grown on maltose or other carbohydrates containing maltose units. Amylase synthesis was more severely repressed by glucose than by xylose. Catabolite repression-resistant mutants were isolated by using nitrosoguanidine treatment, enrichment on 2-deoxyglucose, and selection of colonies with large clear zones on iodine-stained glucose-starch agar plates. Amylases were produced in both wild-type and mutant strains when starch was added to cells growing on xylose but not when starch was added to cells growing on glucose. In both wild-type and mutant strains, glucoamylase and pullulanase were produced at high levels in starch-limited chemostats but not in glucose- or xylose-limited chemostats. Therefore, we concluded that amylase synthesis in C. thermohydrosulfuricum was inducible and subject to catabolite repression. The mutants produced about twofold more glucoamylase and pullulanase, and they were catabolite repression resistant for production of glucose isomerase, lactase, and isomaltase. The mutants displayed improved starch metabolism features in terms of enhanced rates of growth, ethanol production, and starch consumption.This publication has 26 references indexed in Scilit:
- Thermophilic Saccharide FermentationsPublished by Elsevier ,1982
- REGULATION OF AMYLASE SYNTHESIS IN BACILLUS LICHENIFORMIS NCIB 6346FEMS Microbiology Letters, 1980
- Selective isolation of depressed mutants of an α-amylase yeast by the use of 2-deoxyglucoseBiotechnology & Bioengineering, 1980
- Thermophilic bacteria: Ecology, physiology and technologyEnzyme and Microbial Technology, 1979
- Production, Isolation, and Economics of Extracellular EnzymesPublished by Elsevier ,1979
- Utilization of Agricultural Wastes by Aspergillus awamori for the Production of GlucoamylaseZentralblatt für Bakteriologie, Parasitenkunde, Infektionskrankheiten und Hygiene. Zweite Naturwissenschaftliche Abteilung: Allgemeine, Landwirtschaftliche und Technische Mikrobiologie, 1977
- EFFECT OF CARBON SOURCES ON FORMATION OF α-AMYLASE AND GLUCOAMYLASE BY CLOSTRIDIUM ACETOBUTYLICUMThe Journal of General and Applied Microbiology, 1975
- Pullulanase synthesis in Klebsiella (Aerobacter) aerogenes strains growing in continuous cultureBiochemical Journal, 1974
- Proteins from thermophilic microorganisms.1973
- Effect of maltose on glucoamylase formation by Aspergillus niger.1972