UGC (University Grants Commission) Mini Research Project

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

Upendra Thapa Shrestha* and Vishwanath Prasad Agrawal

Research Laboratory for Biotechnology and Biochemistry (RLABB), Sanepa, Lalitpur

* Author of Correspondence (Email: upendrats@gmail.com)

ABSTRACT

Bacterial insecticides have been used for the control of nuisance and vector mosquitoes for more than three decades. Nevertheless, Bacillus thuringiensis are the most commonly used one due to their broad spectrum insecticidal property, environmentally friendly and safe to non-target insects. The only limiting factor in use of B. thuringiensis as bio-mosquitocides is their survival in waste water, the natural breeding sites of mosquito. The study was thus carried out to evaluate the survival and efficiency of B. thuringiensis in such different niches. Seven crystal protein producing isolates were selected for insect bioassay against the mosquito larva of Culex species both in lab and waste water, and further processed for survival test. Among the isolates, S₆ was found to highly potent showing 100% efficiency in killing those mosquito larva in their natural habitat. Other isolates were also found to be highly efficient showing 70-90%. These isolates not only showed mosquitocidal property but also found to be growing in such environment. The growth of B. thuringiensis in waste water was found to be increased for seventh day to about 10¹¹ bacterial count and plunged gradually in subsequent days till 30 days. The number of B. thuringiensis isolates was found to be 10⁶ even upto 30 days in such polluted water. This property of B. thuringiensis adds to their prominent characteristics as bio-mosquitocides which can be commercialized for the control of many mosquito borne diseases.

Key words: Bacillus thuringiensis, Crystal protein, Niches, Bio-mosquitocides, Survival

For Citation: ShresthaUT, Agrawal VP (2014). Survival and efficiency of Bacillus thuringiensis in waste water for biological control of mosquito breeding. The Journal of University Grants Commission, Vol. 3, No. 1,  134-139. (Full article will be available on request).