Rhizobacteria and its biofilm for sustainable agriculture: A concise review

Abstract

Soil as a habitat holds innumerable and diverse microorganisms involved in an array of activities. The soil surrounding the root region, termed the rhizosphere, plays a very significant and important role in plant growth and yield. Due to rapid and quantum rise in global population, agricultural yield has had to be intensified, resulting in the application of hazardous and life-threatening agrochemicals. However, these synthetic fertilizers affect the soil's indigenous properties, decreasing the quality and increasing the health risk/problems to humans and others. The exploitation of rhizospheric bacteria (rhizobacteria) instead of chemical fertilizers has become important for researchers. Bacterial populations linked with each other and sheathed by self-produced exopolysaccharides (EPSs) are termed biofilms. Rhizobacterial biofilms increase the possibilities for sustainable agricultural production, being involved in plant growth and promotion, nutrient and water uptake, and plant stress tolerance. Rhizobacteria and its biofilms implement various mechanisms including atmospheric N2 fixation, polysaccharide production, phosphate solubilization, phytostimulation via production of various biomolecules, biocontrol through antibiotics, lytic enzymes, and volatile compounds along with systemic resistances to carry out the processes. Studies of the genetics of rhizobacterial biofilm have highlighted better applications for its use. This chapter focuses on rhizobacteria and its biofilms as a competent, efficient, and natural fertilizer with basic mechanisms of action and molecular undertakings for promoting plant growth and crop yield. © 2020 Elsevier B.V. All rights reserved.