Evaluation of Different Culture Media for Improvement in Bioinsecticides Production by IndigenousBacillus thuringiensisand Their Application against Larvae ofAedes aegypti

Abstract

Production of indigenous isolate Bacillus thuringiensis sv2 (Bt sv2) was checked on conventional and nonconventional carbon and nitrogen sources in shake flasks. The effects on the production of biomass, toxin production, and spore formation capability of mosquito toxic strain were determined. Toxicity differs within the same strain depending on the growth medium. Bt sv2 produced with pigeon pea and soya bean flour were found highly effective with LC50 < 4 ppm against larvae of Aedes aegypti. These results were comparable with bacteria produced from Luria broth as a reference medium. Cost-effective analyses have revealed that production of biopesticide from test media is highly economical. The cost of production of Bt sv2 with soya bean flour was significantly reduced by 23-fold. The use of nonconventional sources has yielded a new knowledge in this area as the process development aspects of biomass production have been neglected as an area of research. These studies are very important from the point of media optimization for economic production of Bacillus thuringiensis based insecticides in mosquito control programmes.

OTIMIZAÇÃO DE MEIO DE CULTURA PARA PRODUÇÃO DE BIOMASSA DE Bacillus thuringiensis POR METODOLOGIA DE SUPERFÍCIE DE RESPOSTA

“…Na literatura, é amplamente relatada a importância da fonte de nitrogênio no crescimento, Devidas et al (2014) testando meios suplementados com diversas fontes de nitrogênio, observou um grande rendimento de produção de biomassa no meio suplementado com proteína de soja. As fontes de nitrogênio apresentaram efeito significativo no crescimento, pela elevada importância na produção de cristais mais tóxicos, as principais fontes foram proteína de soja e milhocina, com resultados positivos para aumento da produção de biomassa.…”

“…O estimulo da produção de biomassa por sacarose indica a preferência, do B. thuringiensis, por açúcares simples. Estes resultados confirmam os resultados de Devidas et al (2014), onde houve uma redução na produção de biomassa de B. thuringiensis na presença de amido.…”

Biopesticide production using Bacillus thuringiensis kurstaki by valorization of starch industry wastewater and effluent from aerobic, anaerobic digestion

“…1c). Btk cell growth, sporulation and endotoxin synthesis are mechanisms that require energy in the form of ATP from carbon metabolism through the Krebs cycle and oxidative phosphorylation [22]. Table 2 indicates that total organic carbon (TOC) is significantly lower in anaerobic and aerobic effluent than in SIW.…”

Biological control of Culex pipiens mosquito by local bacterial isolates

“…As demonstrated by Devidas et al (2014), basal medium was prepared with different carbon sources: sucrose, sodium succinate, mannitol, lactose and glucose. For the effect of different nitrogen sources, basal medium was used with yeast extract, beef extract, ammonium sulphate, ammonium chloride, soybean and potassium nitrate as nitrogen sources.…”