title: Bioremediation of hexavalent chromate using permeabilized Brevibacterium sp. and Stenotrophomonas sp. cells.
abstract: Bioremediation has been found to be a useful method for removing hexavalent chromium (Cr(VI)), which is very toxic, from wastewater. Two strains of bacteria that were able to reduce Cr(VI) effectively were isolated from Cr(VI) contaminated soil samples and identified as Brevibacterium sp. K1 and Stenotrophomonas sp. D6, respectively, based on 16S rRNA gene sequence analyses. Brevibacterium sp. K1 and Stenotrophomonas sp. D6 could grow in Luria-Broth medium containing K2Cr2O7 at 1000 and 1600 mg/L, respectively, and they completely reduced the Cr(VI) in LB medium containing K2Cr2O7 at 200 mg/L within 72 h. Further analyses revealed that permeabilized K1 and D6 cells reduced Cr(VI) more effectively than did the resting cells. Triton X-100 was the best permeabilizing agent that was tested. The permeabilized cells of both strains could completely reduce Cr(VI) in industrial wastewater twice before needing to be replenished. The results suggested that these chromate-reducing bacteria are potential candidates for practical use biotreating industrial effluents containing Cr(VI) with Stenotrophomonas sp. D6 being the more effective bacterium.
authors.affiliation: College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China; Key Laboratory for Subtropical Water Environment and Marine Biological Resources Protection, Wenzhou 325035, China. Electronic address: geshme@wzu.edu.cn.
authors.forename: Shimei
authors.initials: S
authors.lastname: Ge
authors.affiliation: Department of Research and Development, Shanghai Benegene Biotechnology Co., Ltd., Shanghai 201114, China.
authors.forename: Shichao
authors.initials: S
authors.lastname: Ge
authors.affiliation: College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China; Key Laboratory for Subtropical Water Environment and Marine Biological Resources Protection, Wenzhou 325035, China.
authors.forename: Maohong
authors.initials: M
authors.lastname: Zhou
authors.affiliation: College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China; Key Laboratory for Subtropical Water Environment and Marine Biological Resources Protection, Wenzhou 325035, China.
authors.forename: Xinjiao
authors.initials: X
authors.lastname: Dong
mesh_terms: D001673:Biodegradation, Environmental; D001951:Brevibacterium / Q000378:metabolism*; D002857:Chromium / Q000378:metabolism*; D006801:Humans; D007220:Industrial Waste; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012989:Soil Pollutants / Q000378:metabolism*; D020588:Stenotrophomonas / Q000378:metabolism*; D062065:Wastewater / Q000382:microbiology; D014871:Water Microbiology; D014874:Water Pollutants, Chemical / Q000378:metabolism; D018508:Water Purification / Q000379:methods
chemical_list: D002857:Chromium; D007220:Industrial Waste; D012336:RNA, Ribosomal, 16S; D012989:Soil Pollutants; D062065:Wastewater; D014874:Water Pollutants, Chemical; C074702:chromium hexavalent ion
keywords: 16S rRNA analysis; Brevibacterium sp.; Cr(VI) reduction; Industrial wastewater; Permeabilized cells; Stenotrophomonas sp.