Alleviation of toxic hexavalent chromium using indigenous aerobic bacteria isolated from contaminated tannery industry sites

• Published in: Preparative biochemistry & biotechnology 2016-07, Vol.46 (5), p.517-523
• Main Authors: Pandey, Siddhartha, Singh, Nitin Kumar, Bansal, Ankur Kumar, Arutchelvan, V., Sarkar, Sudipta
• Format: Article
• Language: English
• Subjects: Bacteria; Bacteria, Aerobic - growth & development; Bacteria, Aerobic - metabolism; Biodegradation, Environmental; Bioremediation; Chromium; Chromium - isolation & purification; Chromium - metabolism; Environmental Pollutants - isolation & purification; Environmental Pollutants - metabolism; growth behavior; hexavalent chromium; Industrial Waste; kinetic studies; Kinetics; Streptomyces; Streptomyces sp; Tanning; tolerance; Toxicology
• ISSN: 1082-6068; 1532-2297
• DOI: 10.1080/10826068.2015.1084635

In the last decade, much attention has been paid to bioremediation of Cr(VI) using various bacterial species. Cr(VI) remediation by indegeneous bacteria isolated from contaminated sites of a tannery industry located in Tamil Nadu, India, was investigated in this study. Three Cr(VI) resistant bacterial strains (TES-1, TEf-1, and TES-2) were isolated and selected based on their Cr(VI) reduction ability in minimal salt medium. Among these three bacterial strains, TES-1 was found to be most efficient in bioreduction, while TES-2 was only found to be Cr(VI) resistant and showed negligible bioreduction, whereas TEf-1 was observed to be most Cr(VI) tolerant. Potential for bioremediation of TES-1 and TEf-1 was further investigated at different concentrations of Cr(VI) in the range of 50 to 350 mg L −1 . TEf-1 showed prominent synchronous growth throughout the experiment, whereas TES-1 took a longer acclimatization time. Minimum inhibitory concentrations (MIC) of Cr(VI) for TES-1 and TEf-1 were approximated as 600 mg L −1 and 750 mg L −1 , respectively. The kinetic behavior of Cr(VI) reduction by TES-1 and TEf-1 exhibited zero- and first-order removal kinetics for Cr(VI), respectively. The most efficient strain TES-1 was identified as Streptomyces sp. by gene sequencing of 16S rRNA.