Bacillus thuringiensis insecticide prodn. - without premature cell lysis by maintaining pH of 6.3 to 7 and/or applying anaerobic conditions during cultivation

摘要

Biosynthesis of a microbial insecticide contg. spores and crystalline endotoxin, comprises cultivating the microorganism Bacillus thuringiensis or a related bacillus with spore-formation, in a nutrient medium in so that the early cell-lysis, caused before completion of spore-formation by aeration during the course of the submerged cultivation, is inhibited. The insecticide is pref. sepd. from the toxic water-soluble exotoxin also produced by the microorganism by dialysis. Premature cell-lysis leads to low yields of the insecticide and an increase in its toxicity. This premature cell-lysis is avoided by carrying out the biosynthesis under an-aerobic conditions for 4-6 hrs. at pH 6.3-7.