STUDY OF SURVIVABILITY AND EFFICIENCY OF BACILLUS THURINGIENSIS IN WASTE WATER FOR BIOLOGICAL CONTROL OF MOSQUITO BREEDING

BIO-15

STUDY OF SURVIVABILITY AND EFFICIENCY OF BACILLUS THURINGIENSIS   IN WASTE WATER FOR BIOLOGICAL CONTROL OF MOSQUITO BREEDING

(Abstract Published in The Sixth National Conference on Science and Technology-

Sept.25-27, 2012 Kathmandu)

U. Thapa Shrestha, S. Ghimire, J. Bhandari, K. B. Tiwari and V. P. Agrawal

P.O.Box.-11537, Sundhara

Kathmandu, 44600

email: upendrats@gmail.com

ABSTRACT

Bacillus thuringiensis strains were isolated from soil samples collected from Sagarmatha National Part of the Everest region and subsequently identified by standard microbiological techniques including colonial characteristics, morphological characteristics, crystal protein staining and biochemical characteristics. Some of potent strains already preserved in lab were also revived and recharacterized for their crystal protein production property. The stationary phase culture broth was tested for insect bioassay using mosquito larva collected from stagnant waste water in Kathmandu. All these isolates were able to efficiently kill the mosquito larva even at their natural breeding place, the waste water. These were further used for survivability test in the waste water.  The growth of B. thuringiensis in waste water was found to be soared for seventh days and plunged gradually in subsequent days till 30 days. The survivability of B. thuringiensis isolates was recorded till 30 days and found to be alive in the waste water. The number of B. thuringiensis was found to be higher in control in compare with the test, unautoclaved waste water.