(中南大學(xué) 資源加工與生物工程學(xué)院，長沙410083)
摘 要: 自云南酸性熱泉水樣中分離出一株中度嗜熱硫氧化菌YN12。對其形態(tài)特征和生理生化特性以及16S rDNA序列分析結(jié)果證明，該菌株歸屬于喜溫嗜酸硫桿菌(Acidithiobacillus caldus)。重金屬抗性實(shí)驗(yàn)表明，YN12菌株對3CdSO4∙8H2O具有超強(qiáng)抗性，其最高初始Cd2+耐受濃度達(dá)4.8 g/L。在此基礎(chǔ)上，不斷提升3CdSO4∙8H2O濃度，其最終Cd2+耐受濃度可達(dá)31.5 g /L(相當(dāng)于3CdSO4∙8H2O 210 g/L)。在該最終Cd2+耐受濃度下，經(jīng)過連續(xù)3代的適應(yīng)性生長，YN12菌株的生長速度和硫氧化活性均能得到較好的恢復(fù)。
關(guān)鍵字: 喜溫嗜酸硫桿菌；YN12菌株；鎘抗性；最高耐受濃度
（School of Resources Processing and Bioengineering, Central South University, Changsha 410083, China）
Abstract:A moderately thermophilic sulfur-oxidizing strain, YN12, was isolated from an acidic hot spring sample collected in Yunnan Province, southeastern China. Morphological, physiological and 16S rDNA sequence data suggest that YN12 belongs to the species, Acidithiobacillus caldus. YN12 exhibits a very high degree of resistance to cadmium (Ⅱ), with an original maximum tolerated concentration (MTC) of 4.8 g/L and an ultimate MTC of 31.5 g/L after adapted by a gradually increased concentration of 3CdSO4∙8H2O. Continuously cultured in the medium containing 210 g 3CdSO4∙8H2O/L (equal to 31.5 g/L of Cd2+) for three generations, the strain is capable of restoring its growth and sulfur oxidation activity to an approximately normal level.
Key words: Acidithiobacillus caldus; strain YN12; cadmium resistance; maximum tolerated concentration
