Environmental Microbiology Laboratory, Environmental Toxicology Group, CSIR-Indian Institute of Toxicology Research, Lucknow 226001, Uttar Pradesh, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh 201002, India.
Environmental Microbiology Laboratory, Environmental Toxicology Group, CSIR-Indian Institute of Toxicology Research, Lucknow 226001, Uttar Pradesh, India.
Bioresour Technol. 2022 May;352:127109. doi: 10.1016/j.biortech.2022.127109. Epub 2022 Apr 1.
Biofilm-forming bacteria play a key role in the removal of heavy metals including hexavalent chromium [Cr(VI)] from contaminated sites. In this study, biofilm-forming B. haynesii was examined for extracellular polymeric substances (EPS) production and hexavalent chromium [Cr(VI)] reduction potential. Exposure of B. haynesii with Cr(VI) (12.5-100 mg L) for 48 h enhanced pellicle dry weight (20-24%), cell-size (5.1-23.2%) and cell granularity (8.5-19.2%). Also, EPS production was increased by 10-35% by promoting the synthesis of protein (94-119%) and polysaccharide (2-33%) components in EPS. Further, the reduction (27.7 %) and distribution (15.87%) of Cr(VI) were mainly mediated by EPS than the other cellular fractions. Findings of the study suggest that the EPS from B. haynesii was efficiently reduced to Cr(VI) present in aqueous medium and the potential of the organism can be further explored for the mitigation of Cr(VI) contamination.
生物膜形成细菌在从污染场所去除重金属（包括六价铬 [Cr(VI)]）方面发挥着关键作用。在这项研究中，研究了生物膜形成的 B. haynesii 细胞外聚合物物质（EPS）的产生和六价铬 [Cr(VI)]的还原潜力。将 B. haynesii 暴露于 Cr(VI)（12.5-100mg L）48 小时会增强菌膜干重（20-24%）、细胞大小（5.1-23.2%）和细胞粒度（8.5-19.2%）。此外，通过促进 EPS 中蛋白质（94-119%）和多糖（2-33%）成分的合成，EPS 的产量增加了 10-35%。此外，Cr(VI)的还原（27.7%）和分布（15.87%）主要是通过 EPS 介导的，而不是通过其他细胞部分。研究结果表明，B. haynesii 的 EPS 能有效地将存在于水溶液中的 Cr(VI)还原，并且该生物体的潜力可以进一步探索用于减轻 Cr(VI)污染。
