BACILLUS-THURINGIENSIS SUBSP KURSTAKI SPORE PRODUCTION IN BATCH CULTURE USING BROILER LITTER EXTRACTS AS COMPLEX MEDIA

Broth for the growth of Bacillus thuringiensis subsp. kurstaki was pre pared by extraction of broiler litter with water. Filamentous growth o ccurred during the first 6 h of fermentation in the full strength and in a 2:1 extract dilution. Of the five dilutions examined: the 2:1 dil ution of the extract having a total organic carbon concentration of 1. 7 g/l produced the highest spore count, 2.46 x 10(x) spores/ml. SDS-PA GE analysis of spore-crystal protein produced during the fermentation indicated a molecular weight of approximately 135 000, suggesting the presence of bacterial insecticidal protoxin. With appropriate pretreat ment, broiler litter may be a valuable resource when used as a low-cos t complex medium for production of biochemicals. (C) 1998 Elsevier Sci ence Ltd. All rights reserved.