Importance of Biofilm Formation in Plant Growth Promoting Rhizobacterial Action

Abstract

Among the diverse soil microflora, plant growth promoting rhizobacteria (PGPR) mark an important role in enhancing plant growth through a range of beneficial effects. This is often achieved by forming biofilms in the rhizosphere, which has advantages over planktonic mode of bacterial existence. However, the biofilm formation of PGPR has been overlooked in past research. This chapter focuses on new insights and concepts with reference to improved PGPR effects caused by the biofilm formation by PGPR and its impact on overall plant growth promotion, compared with the planktonic lifestyle of PGPR. Beneficial PGPR play a key role in agricultural approaches through quorum sensing in their biofilm mode. The in vitro production of biofilmed PGPR can be used to give increased crop yields through a range of plant growth mechanisms. They can be used as biofertilizers through improved N2 fixation and micro- and macronutrient uptake. Further, higher levels of plant growth with PGPR have been observed due to their production of plant growth regulators and their abilities to act as biocontrol agents, which are carried out by the production of antibiotics and other antimicrobial compounds. The microbial inoculant industry would also benefit greatly by developing biofilmed PGPR with N2 fixing microbes. Biofilmed PGPR can be manipulated to achieve results in novel agricultural endeavors and hence is as an area which needs a deeper probing into its potential.