中文摘要：

【目的】对1株镉耐受性较强的弯孢属真菌C12进行分类鉴定,评估其对重金属镉的耐受能力,并初步分析和探讨其相关的镉耐性机制,为揭示真菌的重金属抗性机制及其在重金属污染治理中的应用提供依据。【方法】利用形态和分子生物学相结合的方法对菌株C12进行分类鉴定,采用固体和液体2种培养方法研究不同Cd~（2＋）质量浓度（0,20,40,80,160,320mg/L）下菌株C12的生长状况,比较不同Cd~（2＋）质量浓度下菌株C12培养液中pH值和有机酸含量以及菌丝内谷胱甘肽（GSH）和丙二醛（MDA）含量的变化。【结果】菌株C12被鉴定为津田弯孢（Curvularia tsudae）;该菌在Cd~（2＋）质量浓度高达320mg/L时仍有菌丝生长,菌丝体干质量在固体培养时随Cd~（2＋）质量浓度的升高先增加后降低,在Cd~（2＋）质量浓度为20mg/L时达到最大（P〈0.05）,而液体培养时却随Cd~（2＋）质量浓度的升高逐渐降低（P〈0.05）;培养液中柠檬酸和苹果酸的含量较高,琥珀酸仅在高Cd~（2＋）质量浓度（80~320mg/L）时才会产生,未检测到草酸和酒石酸;随Cd~（2＋）质量浓度的升高,柠檬酸、苹果酸、乙酸和琥珀酸质量浓度以及菌丝内的GSH含量均先增加后降低,且在160mg/L时达到最大（P〈0.05）,而培养液的pH值并无显著变化（P〉0.05）,但均显著低于不加镉的对照（P〈0.05）;菌丝内的MDA含量则随Cd~（2＋）质量浓度的升高先增加再降低后又升高,但差异并不显著（P〉0.05）。【结论】津田弯孢C12具有较高的镉耐受性,且液体培养条件下菌丝生长和镉耐受性明显优于固体培养,GSH和有机酸（柠檬酸、苹果酸和琥珀酸）的大量积累可能是其减轻镉毒害、提高镉耐受性的潜在机制之一。

英文摘要：

[Objective] In this study,one isolate of Curvularia sp. C12 which showed high tolerance a- bility to heavy metal cadmium was identified as Curvularia tsudae, and then the related tolerance mecha- nism was preliminarily analyzed and discussed. The results could provide the foundation for revealing the mechanism of fungal resistance to heavy metal,and for the application of fungi to control heavy metal pol- lution. [Method] The taxonomic status of isolate C12 was identified based on its morphological and molec- ular characteristics. Its tolerance ability to cadmium was assessed both in solid and liquid culture condition with different mass concentrations of Cd2＋ （0,20,40,80,160,320 rag/L）, pH value and organic acids con- tents,as well as glutathione （GSH） and malondialdehyde （MDA） contents in the fungal mycelia weremeasured and compared under different mass concentrations of Cd2＋ in liquid culture condition. [Result] I- solate C12 was identified as Curvularia tsudae ,and it could grow under 320 mg/L Cd2＋. Along with the in- crease of Cd2＋ mass concentrations,the mycelia dry weight of C. tsudae C12 was increased firstly and then decreased on solid culture condition,and reached the maximum at 20 mg/L（P〈0. 05） ,but was gradually reduced in liquid culture condition（P~0.05）. In liquid culture condition,oxalic acid and tartaric acid did not be detected, while citric acid and malic acid content were relatively high,and succinic acid was only pro- duced under high concentrations of Cd2＋ （80--320 rag/L）. With the increase of Cd2. mass concentrations, the content of citric acid,malic acid,acetic acid and succinic acid,as well as GSH content in mycelia were in- creased firstly and then decreased,and reached the maximum at 160 mg/L （P%0.05） ;while MDA content in myce[ia was increased firstly,then decreased and later rose again, but did not show significant difference （P〈0.05）. pH values were significant lower than that of control （without cadmium） （P〈0.05） ,howev- er,did