Isolation of Bacillus Sphaericus from the Midgut of Stegomyia (Aedes) aegypti Larvae and its role in larval Development

摘要

Bacillus sphaericus was isolated from the midgut of Stegomyia (Aedes) larva. The isolate tolerated up to 40℃.The isolate was able to grow on nutrient and Tryptone soya agar but unable to Mac Conkey and Eosin-methylene blue agar. Organisms (ranging from 1.87-2.6 μm in length and 0.51-0.68 μm in diameter) were positive for Gram stain, spore and crystal staining. Bacteria were salt tolerant in nature. The bacteria produced protease and lipase and were sensitive to the antibiotics, chloramphenicol, kanamycin, eryrthromycin, ofloxacin, lomefloxacin, tobramycin, doxycycline, gatifloxacin, amikacin, gentamycin, sparfloxacin, cefadroxil. The organism survived as normal flora in the larval gut of Stegomyia (Aedes) aegypti. The antibiotic treated larvae had delayed development to adulthood as compared to the control ones.