Enterobacter: Role in Plant Growth Promotion

Abstract

It is believed that inoculation with rhizobacteria containing plant growth promoting (PGP) characteristics consequently promote root and shoot growth. Further evaluation of these bacteria exhibiting multiple PGP traits on soil–plant system is needed to uncover their efficacy as effective PGP rhizobacteria (PGPR) or PGP bacteria (PGPB) depending upon their nature. The genera within the family Enterobacteriaceae that feature members described as PGPB are Citrobacter, Enterobacter, Erwinia, Klebsiella, Kluyvera, Pantoea and Serratia, although some of these genera also contain species reported to be plant pathogens. Genus Enterobacter is a Gram-negative, straight rod which is motile with peritrichous flagella and is facultatively anaerobic. Enterobacter spp. are known to have a wide range of PGP characteristics involving in nitrogen fixation, soil phosphorus solubilisation, production of antibiotics, having ability to secrete siderophore produce, chitinase, ACC deaminase, hydrolytic enzymes besides exopolysaccharides and in the enhancement of soil porosity. Numerous Enterobacter strains express these activities which promote plant growth and suppress soilborne plant pathogens. These PGP abilities of Enterobacter can make them a potential candidate suitable for plant growth and development. Due to their multifarious role in crop growth, a number of these strains have been developed commercially as plant growth promoters and biocontrol agents.