title: Alleviation of toxic hexavalent chromium using indigenous aerobic bacteria isolated from contaminated tannery industry sites.
abstract: 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.
authors.affiliation: a Department of Civil Engineering , Indian Institute of Technology Roorkee , Roorkee , Uttrakhand , India.
authors.forename: Siddhartha
authors.initials: S
authors.lastname: Pandey
authors.affiliation: a Department of Civil Engineering , Indian Institute of Technology Roorkee , Roorkee , Uttrakhand , India.
authors.forename: Nitin Kumar
authors.initials: NK
authors.lastname: Singh
authors.affiliation: b Department of Civil Engineering , Moradabad Institute of Technology , Moradabad , Uttar Pradesh , India.
authors.forename: Ankur Kumar
authors.initials: AK
authors.lastname: Bansal
authors.affiliation: c Department of Civil Engineering , Annamalai University , Annamalai Nagar , Tamil Nadu , India.
authors.forename: V
authors.initials: V
authors.lastname: Arutchelvan
authors.affiliation: a Department of Civil Engineering , Indian Institute of Technology Roorkee , Roorkee , Uttrakhand , India.
authors.forename: Sudipta
authors.initials: S
authors.lastname: Sarkar
mesh_terms: D001420:Bacteria, Aerobic / Q000254:growth & development / Q000378:metabolism*; D001673:Biodegradation, Environmental; D002857:Chromium / Q000302:isolation & purification* / Q000378:metabolism; D004785:Environmental Pollutants / Q000302:isolation & purification* / Q000378:metabolism; D007220:Industrial Waste; D007700:Kinetics; D013633:Tanning
chemical_list: D004785:Environmental Pollutants; D007220:Industrial Waste; D002857:Chromium; C074702:chromium hexavalent ion
keywords: Bioremediation; Streptomyces sp; growth behavior; hexavalent chromium; kinetic studies; tolerance