EFFECT OF GLUCOSE ON SPORULATION AND EXTRACELLULAR AMYLASE PRODUCTIONBY CLOSTRIDIUM-PERFRINGENS TYPE-A IN A DEFINED MEDIUM

The effect of glucose and other sugars on sporulation and extracellula r amylase production by Clostridium perfringens NCTC 8679 type A in a defined medium was studied. Cells grown in the presence of glucose and mannose yielded the highest levels of amylase activity, while disacch arides such as lactose, maltose, and sucrose resulted in moderate amyl ase production. Little amylase activity was detected in the medium in the presence of ribose or galactose. The concentration of each sugar r esulting in highest amylase production was between 6 and 10 mM except for fructose (25 mM). Levels of heat-resistant spores decreased as sug ar concentrations increased. The addition of even small amounts of glu cose to the medium before exponential growth suppressed sporulation bu t maximized amylase activity. The addition of glucose after the initia tion of sporulation did not inhibit spore formation. However, its addi tion to 3-h amylase-producing cells did inhibit subsequent sporulation but promoted the continued excretion of amylase. The different respon se to glucose between sporulating cells and amylase-producing cells su ggests that the mechanisms of catabolite repression of extracellular a mylase production and sporulation are distinct in this strain of C. pe rfringens.