Characterization of pesticidal crystal toxin protein Cry11Aa from Bacillus thuringiensis serovar israelensis VCRC-B646 for mosquito control.

Effective mosquito control is essential for reducing the transmission of vector-borne diseases. This study focuses on the comprehensive characterization of mosquitocidal toxins produced by Bacillus thuringiensis serovar israelensis (Bti) VCRC B646 and the associated insecticidal genes. The bacterium was cultured, and the spore-crystal complex was purified to identify the mosquitocidal proteins. The isolate produced mosquitocidal toxins were effective against Aedes aegypti , Anopheles stephensi , and Culex quinquefasciatus , Toxicity bioassays indicated lethal concentrations (LC ₅₀ and LC ₉₀ ) for Aedes aegypti (0.0022 mg/L and 0.004 mg/L), and Culex quinquefasciatus (0.0025 mg/L and 0.0044 mg/L). SDS-PAGE and LC-MS analysis revealed that Cry11Aa5 (Pesticidal Crystal Protein) is the predominant toxin produced by this strain. PCR amplification confirmed the presence of genes encoding various insecticidal proteins, including Cry and Cyt toxins. Phylogenetic analysis was performed to assess the genetic relatedness and toxin profiles of the bacterial isolate. This detailed characterization of Bti VCRC B646 highlights its potential as a promising biopesticide candidate for mosquito control, contributing to the development of sustainable and eco-friendly strategies for vector management.