Heavy metal stress tolerance in Enterobacter sp. PR14 is mediated by plasmid

Abstract

Last two decades have witnessed the significant exploitation of many plant growth-promoting rhizobacteria (PGPR) as bioinoculants and biocontrol agents (BCAs). However, PGPR with potential of producing multiple biocontrol traits along with heavy metal stress tolerance and ACC deaminase activity are expected to control phytopathogens and increase tolerance of crop to heavy metal stress, thus helping in bioremediation of heavy metal ions and reducing ethylene level in the root zone. The present work reports the production of multiple biocontrol traits like ammonia (NH₃), hydrogen cyanide (HCN), siderophore (79%), ACC deaminase (0.8 µM/mg/h), chitinase (9.7 U/mL) and tolerance to heavy metal ions (3200 μg/mL) and trace minerals in Enterobacter sp. PR14 isolated from the model organic farm of Sam Higginbottom University of Agriculture, Technology and Sciences (SHUATS), Allahabad, India. Elimination of plasmid in the organism resulted in the loss of tolerance of heavy metal ions and trace elements, indicating the role of the plasmid in heavy metal tolerance.