title: Bioaccumulation and biosorption of Cd(2+) and Zn(2+) by bacteria isolated from a zinc mine in Thailand.
abstract: The three bacteria, Tsukamurella paurometabola A155, Pseudomonas aeruginosa B237, and Cupriavidus taiwanensis E324, were isolated from soils collected from a zinc mine in Tak Province, Thailand. Among these bacteria, P. aeruginosa B237 and C. taiwanensis E324 were tolerant of both cadmium and zinc, while T. paurometabola A155 was highly tolerant of zinc only. Bioaccumulation experiment revealed that Cd(2+) and Zn(2+) were mainly adsorbed on the cell walls of these bacteria rather than accumulated inside the cells. During Cd(2+) and Zn(2+) biosorption, P. aeruginosa B237 and T. paurometabola A155 showed the highest removal efficiencies for Cd(2+) and Zn(2+), respectively. The maximum biosorption capacities of P. aeruginosa B237 and T. paurometabola A155 biomasses for Cd(2+) and Zn(2+) biosorptions were 16.89 and 16.75 mg g(-1), respectively, under optimal conditions. The experimental data of Cd(2+) and Zn(2+) biosorptions fitted well with Langmuir isotherm model, suggesting that Cd(2+) and Zn(2+) adsorptions occurred in a monolayer pattern on a homogeneous surface. Furthermore, the pseudo-second order and pseudo-first order kinetic models best described the biosorption kinetics of Cd(2+) and Zn(2+) adsorptions, respectively, suggesting that the Cd(2+) and Zn(2+) adsorptions took place mainly by chemisorption (Cd(2+)) and physisorption (Zn(2+)).
authors: Department of Biology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand; Center of Excellence on Environmental Health and Toxicology, CHE, Ministry of Education, Thailand.
authors: Tossapol
authors: T
authors: Limcharoensuk
authors: Department of Biology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand; Center of Excellence on Environmental Health and Toxicology, CHE, Ministry of Education, Thailand.
authors: Najjapak
authors: N
authors: Sooksawat
authors: Department of Biology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand.
authors: Anchana
authors: A
authors: Sumarnrote
authors: Department of Biology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand.
authors: Thiranun
authors: T
authors: Awutpet
authors: Department of Biology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand; Mahidol University International College, Nakhonpathom 73170, Thailand.
authors: Maleeya
authors: M
authors: Kruatrachue
authors: Department of Biology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand; Center of Excellence on Environmental Health and Toxicology, CHE, Ministry of Education, Thailand.
authors: Prayad
authors: P
authors: Pokethitiyook
authors: Department of Biology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand; Center of Excellence on Environmental Health and Toxicology, CHE, Ministry of Education, Thailand. Electronic address: choowong.aue@mahidol.ac.th.
authors: Choowong
authors: C
authors: Auesukaree
mesh_terms: D000327:Adsorption; D018533:Biomass; D002104:Cadmium / Q000737:chemistry / Q000302:isolation & purification*; D002473:Cell Wall / Q000737:chemistry; D003352:Corynebacterium / Q000254:growth & development; D049921:Cupriavidus / Q000254:growth & development; D007700:Kinetics; D008906:Mining; D011550:Pseudomonas aeruginosa / Q000254:growth & development; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000737:chemistry / Q000302:isolation & purification*; D013785:Thailand; D015032:Zinc / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D012989:Soil Pollutants; D002104:Cadmium; D015032:Zinc
keywords: Bioaccumulation; Biosorption; Cadmium; Heavy metal-resistant bacteria; Zinc