Chapter 15 - Insights into the genomes of microbial biopesticides

Abstract

Microbial biopesticides include several microorganisms like bacteria, fungi, baculoviruses, and nematode-associated bacteria acting against invertebrate pests in agro-ecosystems. The most commonly used microbial biopesticides are living organisms, which are pathogenic for the target pest. These include biofungicides namely, Trichoderma and penicillium, bacteriacidal such as, Pseudomonas, Bacillus, bioherbicides (Phytophthora), and bioinsecticides (Bt). They contain microorganism which suppresses pests either by producing toxic metabolites specific to the pest, inhibition of other microorganisms through competition, or various other modes of action. With respect to successful use of entomopathogenic bacterium Bacillus thuringiensis and few other microbial species from more than decades, have led to tfhe discovery of new microbial species and strains with specific toxins and virulence factors. Bacterial entomopathogens include several Bacillaceae, Serratia, Pseudomonas, Yersinia, Burkholderia, Chromobacterium, Streptomyces and Saccharopolyspora species; while fungi comprise different strains of Beauveria bassiana, Beauveria brongniartii, Metarhizium anisopliae, Verticillium, Lecanicillium, Hirsutella, Paecilomyces, and Isaria species. Bacillus thuringiensis is an important microbial biopesticide for controlling agricultural pests by the production of toxic parasporal crystals proteins. Baculoviruses are species-specific and refer to niche products active against chewing insects, especially Lepidopteran caterpillars. Entomopathogenic nematodes mainly include species in the genera Heterorhabditis and Steinernema associated with mutualistic symbiotic bacteria belonging to the genera Photorhabdus and Xenorhabdus. An updated collection of current knowledge on genetic analysis of microbial biopesticides and protocols that are used in integrated pest management programs in agro-ecosystems is reported here. The present chapter is focused on the updated overview of recent research scenario on genomes of organisms involved in development of microbial biopesticides.