Heavy metals bio-removal potential of the isolated Klebsiella sp TIU20 strain which improves growth of economic crop plant (Vigna radiata L.) under heavy metals stress by exhibiting plant growth promoting and protecting traits

Abstract

Toxic heavy metals, chemical fertilizer and fungicides are mutagenic substances that are becoming increasingly common as a result of urbanization and industrialization. Plants, animals, humans, and the environment as a whole are all affected by these. The elimination of these contaminants is become a worldwide concern. The bio-removal effectiveness of heavy metals, protection against the phytopathogen Rhizoctonia solani , and stimulation of growth in Vigna radiata L. under heavy metals stress by Klebsiella sp. strain TIU20 (KTIU20) was isolated and identified in this study. KTIU20 shows bio-removal capacity for heavy metals by biodegradation, biofilm formation, extracellular polymeric substances (EPS), bioaccumulation , and bio-sorption. The KTIU20 also exhibited in vitro antagonism against the soil-borne pathogen Rhizoctonia solani via creating volatile organic compounds (VOCs) and proteases. The insoluble phosphate solubilization (59.1 μg/ml), production of indole acetic acid (39.5 μg/ml) and ammonia (14.6 μg/ml) by KTIU20, displays plant growth boosting properties that encourage Vigna radiate L. growth when exposed to heavy metals in pot experiment. KTIU20 may be employed as an effective plant growth candidate in agricultural soil, contaminated with heavy metals and fungal pathogen near industrial area. • Heavy metals tolerant bacterium Klebsiella sp strain TIU20(KTIU20) was isolated. • It removes heavy metals by degradation, bioaccumulation, EPS and absorption. • It showed PGP traits and antagonistic role against Rhizoctonia solani ( R.solani ). • It promotes plant growth of mung bean ( Vigna radiata L.) under heavy metals stress. • KTIU20 can be used as a bioremediating agent, plant defender and growth enhancer.