β-1.3.-1.4-Glucanase in spore-forming microorganisms. VI. Genetic instability of β-glucanase production in a high-producer strain ofBacillus amyloliquefaciens grown in a chemostat

Publisher Website
Google Scholar
Abstract
A Bacillus amyloliquefaciens strain high-producing for beta-1.3-1.4-glucanase has gradually lost the ability to produce this enzyme during long-time continuous cultivation, independent of the culture conditions. Mutant strains isolated after long-term cultivation exhibited changed behaviour concerning extracellular enzyme formation and sporulation. By agarose gel electrophoresis of alkaline DNA extracts isolated form original and mutant strains we demonstrate that the observed pleiotropic phenomena are not caused by the loss of a complete plasmid present in the original strain. From extracts of both the original and mutant strains plasmid DNAs with approximately the same molecular weight of about 35 Mdal were isolated.