Cr (VI) Reduction by Indigenous Bacillus Species PB5 Isolated from Contaminated Soil of Abeokuta Ogun State, Nigeria

Abstract

Chromium (VI) contamination has accelerated due to rapid industrialization worldwide. Aim of this study is to check the bacterial species for their tolerance towards chromium (VI), chromium (VI) reduction under various pH and further check whether these bacteria are reducing Cr (VI) und er the influence of various metals, carbon source and protein denaturant. Bacterial strains were isolated from metal contaminated soils of Abeokuta. All of the isolates showed tolerance to chromium (VI). Among all the strains, only Bacillus species PB5 showed reduction of Chromium (VI). Maximum reduction (90%) of chromium (VI) was observed at pH 7 by Bacillus species PB5. Similarly, Bacillus species PB5 also reduced the chromium considerably at pH 6 (86%) and pH 8 (87.5%) at a concentration of 100 μg Cr mLG 1 after 120 h of incubation. Bacillus species PB5 also showed chromium (VI) reduction under various metals, protein denaturant and carbon source. There was maximum decrease in Cr (VI) reduction under the influence of PbCl 2 which was followed by ZnCl 2. Urea and citrate also decreased Cr (VI) reduction compared to control cells. Due to above properties strains could therefore be used as bioremediators of metals in soils contaminated with heavy metals.

Screening and Characterization of Hexavalent Chromium Degrading Bacteria From Industrial Samples

“…Microorganism populations have been noted to point out resistance to the maximum amount as 500 mg/l chromium (VI) [13][14][15] that supports the positive growth of strain 1.5 up to 80 mg/l concentration and strain 2.4, a positive growth up to 100 mg/l. Similarly, Wani et al (2015) reportable that microorganism strains were resistant to chromium (VI). Among the microorganism strains, enterobacteria sp.…”

“…The tree of the microorganism Bacillus strain ANUES03 reveals that this specific microorganism strain has been originated directly from associate degree unknown common antecedent. This unknown common antecedent has additionally given rise to 5 connected strains from several intermediate strains through many genomic variations on varied generations [26][27][28][29][30]. None of those connected strains show serious metal tolerance; which can ensure the genomic variations that had occurred on varied generations.…”

Role of chromium reductases, antioxidants, and biosorption against oxidative damage of metals by Bacillus cereus

“…This study observed dose-dependent metals (100-500 mg/L) influence on adsorption by strain PY3 at 30 ± 2°C (pH 7) using strain PY3 dry biomass as an adsorbent incubated for 24 h. The influence of pH (3)(4)(5)(6)(7)(8)(9)(10) and time (0-24 h) was also undertaken for adsorption studies by adding 0.1 g/mL Zn and Cr in a solution containing biomass. Subsequently, biomass was then centrifuged at 5724g for 1/6th of hour to get unsinkable mass to access Zn and Cr 6+ .…”

“…Bacteria and fungi reduce the pollution of this metal by converting this form of metal into a form [Cr (III)] of less pollution [1,[5][6][7]. Detoxification mechanism is being reported in Pseudomonas, Bacillus, Streptococcus, and Klebsiella [3,[8][9][10][11][12]. The mechanism by which bacterial and fungal species convert Cr 6+ to Cr 3+ is the production of reductase enzyme reported Aspergillus niger, Microbacterium sp., and Bacillus thuringgiensis [13,14].…”