Potentials of some agroindustrial byproducts and plant proteins as media for growth and sporulation of Bacillus thuringiensis subsp. aizawai HD-133.

摘要

A comparative study was conducted to evaluate the potential of some protein-rich agroindustrial byproducts and legumes to support growth and formation of spore- delta -endotoxin complex of Bacillus thuringiensis. (B. thuringiensis) subsp. aizawai, HD-133. Soyabean and faba bean seeds (4-5% w/v) produced the highest growth with formation of delta -endotoxin crystals in high frequencies. Offals meal, minced meat-bone meal and fodder yeast recorded efficient yielding, high growth and sporulation titres. Supplementation of soyabean medium with either cane molasses or fodder yeast (2% w/v) increased growth and sporulation. Amino acid patterns of protein hydrolysates of efficient substrates showed high glutamic and aspartic acids in their protein whereas amino acids inhibitory to B. thuringiensis sporogenesis such as cysteine and tryptophan were present in very low percentages. Amino acid analysis of spore delta -endotoxin complex of B. thuringiensis subsp. aizawai HD-133 showed the highest percentage of glutamic and aspartic acids contributing 12.8% and 9.1%, respectively, to the total with only low percentage of cysteine (0.67%) and tryptophan (0.35%). The relationship between these amino acids patterns is discussed..