Enzymatic detoxification of azo dyes by a multifarious Bacillus sp. strain MR-1/2-bearing plant growth-promoting characteristics

Abstract

This study was conducted to elucidate the inherent potential of Bacillus sp. MR-1/2, which was isolated from root zone of maize crop grown on a textile wastewater-irrigated soil. The isolated strain was identified through its ribosomal RNA sequence. Under in vitro conditions, the strain demonstrated its tolerance for high concentrations of various heavy metal ions as determined by minimum inhibitory concentration. Moreover, the strain MR-1/2 exhibited many important phytobeneficial traits such as inorganic P solubilization and 1-aminocyclopropane-1-carboxylate (ACC) deaminase ability even under high metal and salt stress. Results showed that the strain proficiently decolorizes various azo dye compounds, e.g., reactive black-5, reactive red-120, and direct blue-1 and congo red, in broth culture. The bioremediation potential of the strain MR-1/2 was further confirmed by analyzing the retrieved azoreductase gene sequence through bioinformatics tools, whereby a subsequent prediction revealed that the azoreductase enzyme activity was involved in decolorization process. When mung bean seeds were grown in pots under various concentrations of decolorized and non-decolorized azo dye, the Bacillus sp. MR-1/2 not only alleviated the azo dye toxicity, but also increased the plant growth parameters. In conclusion, the strain MR-1/2 efficiently decolorized the azo dyes and helped in mung bean plant growth by alleviating azo dye toxicity.

Effects of Bacillus sp. MR‐1/2 and magnetite nanoparticles on yield improvement of rice by urea fertilizer under different watering regimes

“…Moreover, the strain was positive for ACC deaminase activity at temperatures from 35 to 45°C. These results confirmed the findings of Shahid et al (2018).…”

“…This might be due to the fact that the PhBR strain Bacillus sp. MR-1/2 was declared positive for P solubilization in a previous study (Shahid et al 2018) and showed higher P solubilization at temperature ranges from 35 to 45°C in vitro in present study. Our results are similar to those of previous studies where an increased available P contents in soil due to the application of phosphate solubilizing rhizobacteria was reported (Hussain et al 2016;Tahir et al 2018;Ijaz et al 2019).…”

“…PhBR strain Bacillus sp. MR-1/2 (accession # MG548383) positive for P solubilization and ACC deaminase production (Shahid et al 2018) was obtained from Department of Bioinformatics and Biotechnology, Govt. College University, Faisalabad, Pakistan.…”

Amelioration of disulfonated Acid Red and hexavalent chromium phytotoxic effects on Triticum aestivum using bioremediating and plant growth-promoting Klebsiella pneumoniae SK1

“…Interestingly, SK1 treated plants showed increased shoot and root growth in comparison to untreated as well as control water treated plants, likely due to the presence of PGPP in the spent media. IAA producing K. pneumoniae was found to induced rooting in Cicer arietinum which also contributed to toxicity reversal of azo dye 40 . In a previous study, seeds of S. vulgare and P. mungo exposed to untreated reactive black 5(RB5) exhibited 50% and 60% germination inhibition respectively as compared to exposure with S. halophila treated RB5 biodegradative metabolites 41 .…”

Bacillus firmus strain FSS2C ameliorated oxidative stress in wheat plants induced by azo dye (reactive black-5)

“…Genomic DNA extraction and amplification of 16S rRNA gene of the strain FSS2C were carried out as described by Shahid et al (2018a). The genomic DNA of strain FSS2C was isolated by the CTAB method as reported by Wilson (2001) and DNA was quantified through spectrophotometer using Nano Drop™ 2000/2000c (Thermo Fisher Scientific, USA).…”