Evaluation of industrial by-products for the production of Bacillus thuringiensis strain GP139 and the pathogenicity when applied to Bemisia tabaci nymphs

Abstract

Three industrial by-products were evaluated to produce Bacillus thuringiensis strain GP139: molasses with soybean flour, nejayote with sucrose, cheese-whey with sucrose and HCT as a control media. B. thuringiensis cultures were grown in 250-mL shaking flasks containing 100 mL of medium, 5.9 × 10 8 spores/mL and 1.36 mg/mL of total protein were obtained using molasses with soybean flour medium, and 4.95 × 10 8 spores/mL and 0.78 mg/mL of total protein were produced with the cheese-whey plus sucrose medium. HCT medium yielded a 2.71 × 10 8 spores/mL and 0.84 mg/mL of total protein, and finally, the nejayote and sucrose medium yielded 2.04 × 10 8 spores/mL and 0.54 mg/mL of total protein. In bioassays conducted under greenhouse conditions, no statistically significant differences were observed in the mortality of Bemisia tabaci (Gennadius) (Hemiptera Aleyrodidae) nymphs treated with the B. thuringiensis spore-crystal complexes produced using the four media compared with chemical insecticide.