Burkholderia cepacia BAM-12 isolated from mungbean field in Rajasthan augments plant growth in agricultural field soil of Gujarat, India

Abstract

Application of exotic bacterial strains as biofertilizer has always posed a constraint in the success of biofertilizer technology. Only a limited number of biofertilizers with applicability in a wide range of soil conditions is available in the market. Pseudomonas cepacia BAM-12 (MTCC No. 7100) (now known as Burkholderia cepacia), an isolate from the mungbean rhizosphere of the agricultural field of Rajasthan has shown remarkable plant growth promotion in Gujarat agricultural field soil. B. cepacia was found to increase the overall growth of 3 agriculturally important plants widely grown in Gujarat region, viz., mungbean, maize and rice. Increased plant growth was assessed on the basis of increased leaf number and area, biomass, chlorophyll content, profuse adventitious root branching, increased nodulation (in mungbean only), high available P in soil and overall plant growth in B. cepacia treated plants. Vital factor towards increased plant growth was the amount of IAA secreted by the organism (i.e. 2.65 mg IAA/100 ml of the culture filtrate) which is reasonably high in comparison to earlier reports available. Furthermore, PSB has also demonstrated bioremediation potential against harmful heavy metals such as copper, lead, nickel and arsenic by tolerating upto 25 mM indicating it’s prospective in remediating heavy metal contaminated agricultural fields.