nutritional requirements of bacillus thuringiensis during different phases of growth, sporulation and germination evaluated by plackett-burman method

the effects of different sources of carbon, nitrogen and some of trace elements on cultivation of bacillus thuringiensis h14 were studied. glucose, glycerol, sodium acetate, (nh4)2so4, corn steep liquor, yeast extract, hydrolyzed casein, ca2+, mg2+ and mn2+ were the main parameters evaluated by plackett-burman statistical method. all elements have insignificant effect on germination while spore production was mainly affected by corn steep liquor. growth was affected by corn steep liquor, mnso4 and sodium acetate. the following medium has been proposed based on the responses to growth and sporulation of b. thuringiensis h14: glucose, 5 g/l; glycerol, 1 g/l; sodium acetate,0 g/l; (nh4)2so4, 1 g/l; corn steep liquor, 2 ml/l; yeast extract, 1 g/l; hydrolyzed casein, 1 g/l; cacl2, 20 mg/l; mgso4, 50 mg/l; mnso4 100 mg/l; feso4, 0 mg/l.this medium resulted in a maximum spore count.