Yilmaz E Ince
University of Dicle, Faculty of Sciences, Department of Biology, 21280 Diyarbakir, Turkey.
Res Microbiol. 2003 Jul-Aug;154(6):409-15. doi: 10.1016/S0923-2508(03)00116-5.
A heavy-metal-resistant bacterium Bacillus sp., strain EB1 was isolated from heavy-metal-contaminated soil in the southeast region of Turkey. Based on 16S ribosomal DNA sequencing, the microorganism was closely related to Bacillus circulans. Minimal inhibitory concentrations of metals (MICs) for the bacterium were determined. Bacillus EB1 exhibited high MIC values for metals and a large spectrum of antibiotic resistance. The order of toxicity of the metals to the bacterium was Cd=Co>Cu>Ni>Zn>Mn in solid media. The effects of increasing metal concentrations to the growth rate were determined in order to obtain precise patterns of resistance in liquid cultures. From the results of heavy metal toxicity, inhibitory concentrations in solid media were higher than those in liquid media. Metal biosorption was determined during the course of growth. B. circulans strain EB1 was capable of removing 90% of Mn, 68% of Zn, 65% of Cu, 45% of Ni and 40% of Co during the active growth cycle with a specific biosorption capacity of 25, 22, 20, 13 and 12 mg/l, respectively. Since Bacillus cells could grow in the presence of significant concentrations of metals and due to high metal biosorption capacity in aerobic conditions, this bacterium may be potentially applicable in in situ bioremediation of heavy-metal-contaminated aqueous systems.
从土耳其东南部重金属污染土壤中分离出一株抗重金属细菌芽孢杆菌属EB1菌株。基于16S核糖体DNA测序，该微生物与环状芽孢杆菌密切相关。测定了该细菌对金属的最低抑菌浓度（MICs）。芽孢杆菌EB1对金属表现出高MIC值和广泛的抗生素抗性。在固体培养基中，金属对该细菌的毒性顺序为Cd=Co>Cu>Ni>Zn>Mn。为了获得液体培养物中精确的抗性模式，测定了增加金属浓度对生长速率的影响。从重金属毒性结果来看，固体培养基中的抑制浓度高于液体培养基中的抑制浓度。在生长过程中测定了金属生物吸附。环状芽孢杆菌EB1菌株在活跃生长周期内能够分别去除90%的锰、68%的锌、65%的铜、45%的镍和40%的钴，其比生物吸附容量分别为25、22、20、13和12mg/l。由于芽孢杆菌细胞能够在高浓度金属存在的情况下生长，且在有氧条件下具有高金属生物吸附能力，因此该细菌可能潜在地适用于重金属污染水体系的原位生物修复。
