Whole genome sequencing and evolutionary significance of a novel mosquitocidal bacterium, Bacillus thuringiensis serovar israelensis VCRC-B650 reported from Union Territory of Puducherry, India highly useful for mosquito control.

Abstract

Mosquito-borne diseases pose a significant global health challenge, highlighting the need for innovative biocontrol agents. In this study, a novel mosquitocidal bacterium was isolated from clay soil and subjected to Whole Genome Sequencing (WGS) and bioinformatics analysis to understand its genetic composition and potential applications. WGS revealed that the bacterium a circular genome of size 6,622,317 bp comprising 6930 genes, 115 tRNA and 17 rRNA. The (G + C)s content was found to be 34.83% at the contig level and 34.83% at the scaffold level. Bioinformatics tools, including KmerFinder, Bacterial and Viral Bioinformatics Resource Center and JSpecies, identified the strain as Bacillus thuringiensis serovar israelensis (Bti VCRC-B650). Additionally, eight plasmids were identified in its genome. Notably, the genome analysis confirmed the presence of Cry4Ba, Cry10Aa, Cry15Aa, Cry4Aa, Cry11Aa, Cyt1Aa, Cyt2Ba, Cry2Aa, and Cyt2Ba1 toxins which were considered to be the principal factor of evolutionary significance for mosquitocidal activity. Further analysis identified four different types of Clustered Regularly Interspaced Short Palindromic Repeats sequences, 16 Biosynthetic Gene Clusters, and 312 antibiotic resistance genes. Comparative genomic analysis revealed a total of 556 core genes in Bti VCRC-B650 strain. This study highlights the potential of WGS in characterizing microbial strains with biocontrol properties. The findings suggest that the newly identified Bti VCRC-B650 strain could serve as a promising biological control agent against mosquito larvae and may also have applications in antibiotic and antifungal compound development.