Chapter 3 - Bacillus: Plant Growth Promoting Bacteria for Sustainable Agriculture and Environment

Abstract

Application of plant growth-promoting rhizobacteria (PGPR) for alleviating environmental changes holds quite significance nowadays in the context of changing climate and excessive fertilizer use in agricultural soils. The use of these beneficial microorganisms is considered as one of the most promising methods for safe crop-management practices as it maintains soil fertility and quality. Among various PGPR genus, Bacillus is one of the most extensively studied rhizobacteria that promotes plant growth and development. Earlier studies have reported several strains of Bacillus sp., viz., B. amyloliquifaciens, B. licheniformis, B. megaterium, B. pumilus, B. subtilis, etc., as well-known rhizosphere residents of many crops that show plant growth-promoting activities. Bacillus is a Gram-positive, aerobic, and endospore-forming bacteria. This genus is classified into groups, namely Bacillus, Paenibacillus, Brevibacillus, Lysinibacillus, and Viridiibacillus. The growth promotion characteristics of this genus include production of phytohormones, 1-aminocyclopropane-1-carboxylate deaminase and siderophore production, and phosphate solubilization. Some Bacillus sp. also exhibit property of antibiosis and induction of plant systemic resistance against pathogens. Thus, there are number of publications indicating significant performance of Bacillus in sustainable agriculture. This chapter thus takes into account our current state of knowledge about Bacillus sp. in plant growth promotion, biocontrol, and also in phytoremediation.