A report on novel mosquito pathogenic Bacillus Spp. isolated from a beach in Goa, India

Abstract

Nine Bacilli were isolated from 3 spatially diverse zones viz., tidal, intertidal and seashore at Miramar beach in Goa, India. The isolates were assessed for mosquito larvicidal activity against 3rd instar larvae of Anopheles stephensi, Culex quinquefasciatus, Aedes aegypti and Aedes albopictus. Colony and biochemical characteristics of the isolates showed similarity to Bacillus sphaericus Neide 2362 and Bacillus thuringiensis var. israelensis H-14 commercial strains. Preliminary toxicity screening indicated that four isolates (B1C, C1A, C2A and C2C) possessed mild to high toxicity (60-100 percent mortality) and were further assayed to obtain LC sub(50) and LC sub(90) values following a 24 and 48 hour treatment period. Phylogenetic analysis revealed that these isolates clustered with mild and highly toxic strains of Bacillus, Lysinibacillus and Aneurinibacillus sp. This is the first lead on the presence of mosquito pathogenic bacterial isolates native to Miramar beach in Goa which can be further explored for development of formulations for vector control.