土壤中耐受Mn(Ⅱ)真菌菌株的分离及氧化Mn(Ⅱ)特性研究

Studies on Mn(Ⅱ)-tolerant Fungi:Their Isolation from Soil and Manganese-oxidizing Characteristics

采用分离纯化的方法从锰矿企业含锰土壤中筛选分离能够耐受并氧化二价锰离子(Mn(Ⅱ))的真菌,并研究分离菌株的生长特性及对Mn(Ⅱ)的氧化能力。共分离得到4株具有耐受Mn(Ⅱ)的真菌菌株,分别为XS2-1,XS2-2,XS3-2-4,XS3-2-5。其中XS2-2,XS3-2-4,XS3-2-5能够将Mn(Ⅱ)氧化生成锰氧化物(Mn(Ⅲ,Ⅳ))。根据ITS(Internal Transcribed Spacer)rRNA基因测序结果,这4株真菌菌株分别属于Cladosporium、Plectosphaerella、Epicuccum和Phaeosphaeriopsis属。考察了pH值以及Mn(Ⅱ)浓度对菌株生长和氧化Mn(Ⅱ)能力的影响。发现这4株真菌菌株的生长受pH值影响较小,但受Mn(Ⅱ)浓度影响较大;菌株的Mn(Ⅱ)氧化能力受pH值和Mn(Ⅱ)浓度的影响均较为显著。菌株XS3-2-5的Mn(Ⅱ)氧化能力最为突出,随着Mn(Ⅱ)浓度的增加(最高至15 000μmol/L),其Mn(Ⅱ)氧化能力不断升高,并未出现不耐受的情况。能够氧化Mn(Ⅱ)的真菌菌种的发现对于治理受锰污染的水及土壤具有潜在的实际意义。

Four different species of fungi,named XS2-1,XS2-2,XS3-2-4 and XS3-2-5,were isolated from soil contaminated by Mn using cultivation techniques. According to the ITS（internal transcribed spacer）rRNA sequencing data,these four isolated fungi belonged to genus Cladosporium,Plectospaerella,Epicuccum and Phaeosphaeriopsis respectively.Studies on these fungal isolates involved evaluating impacts of pH and Mn（Ⅱ）concentration on growth of the fungal isolates,which indicated that their Mn-oxidizing capabilities were greatly influenced by both pH and Mn（Ⅱ）concentration. XS3-2-5was the best in Mn（Ⅱ）-oxidizing capability with the Mn（Ⅱ） concentration tolerance being as high as 15 000 μmol/L.Results of the studies is of considerable meanings in remediation of soil and water polluted by manganese.