Simultaneous bioremediation of heavy metals and biodegradation of hydrocarbons by metal resistant<i>Brevibacillus parabrevis</i>OZF5 improves plant growth promotion
Parvaze Ahmad Wani, Nusrat Rafi, Uzma Wani, Hashirudeen Bilikis A, M. S. Khan
Abstract
This study observed role of OZF5 for adsorption, transformation, biodegradation and detoxification and their effect in augmenting bean growth in metal amended pots. Brevibcillus parabrevis OZF 5 (accession number KX276150) significantly removed metals [Cr (VI) and Zn) by biosorption and Cr (VI) reduction. Gene amplification by PCR detected Cr (VI) reductase gene (ChR) and related protein in OZF5 which could be a mechanism responsible for Cr (VI) tolerance. Cytosolic reduction of Cr (VI) and biofilm formation may be actual mechanism of reduction. Bacterial strain OZF5 was also able to degrade wide variety of hydrocarbons in soil contaminated with petroleum. Inoculation of bean with OZF5 reduced production of eDNA [99.97% for both Cr (VI) and Zn], superoxide anions [89.18% for Cr (VI) and 84.61% for Zn], malondialdehyde (MDA) [41.48% for Cr (VI) and 45.88% for Zn], ascorbate [50.70% for Cr (VI) and 47.40% for Zn], catalase [22.51% for Cr (VI) and 51.93% for Zn] compared to un-inoculated but amended with Cr (VI) and Zn. Exopolysaccharide production did not decrease under metals stress. OZF5 completely prevented uptake of metals instead accumulated more nutrients which enhanced bean growth. Present study proved OZF5 to be a super-bioinoculant which could protect plants against oxidative damage.