一株耐铝隐球酵母菌株5-2的分离鉴定及耐铝特性分析

Isolation of an Aluminum-resistant Cryptococcus podzolicus strain 5-2 and its Aluminum tolerance analysis

目的分离高耐铝的微生物菌株,为耐铝基因克隆和耐铝机制研究奠定基础。方法用含5 mmol/L铝的平板逐级筛选和纯化,PCR扩增ITS序列和26S r DNA D1/D2序列,用菌株在不同铝浓度的固体培养基和液体培养基中的生长状况鉴定耐铝能力,用ICP-AES测量菌液上清中剩余活性铝的含量。结果通过ITS序列和26S r DNA D1/D2序列比对及形态观察,初步鉴定该菌株为Cryptococcus podzolicus,该菌株的最大耐铝能力达到100 mmol/L,而且该菌株能够吸附溶液中的活性铝,这可能是其耐铝的原因之一。结论该菌种是首次发现具有耐铝能力,从而为土壤微生物耐铝机制的研究及克隆耐铝基因提供了很好的实验材料。

Objective To isolate aluminum（ Al）-resistant strains and provide base for clone Al-tolerant genes and research aluminum-resistant mechanism. Methods The strain was isolated and puried on GM media supplemented with 5 mmol / L Al3 ＋. The ITS（ Internal transcribed spacer,ITS） region and the D1 / D2 region of the 26 S r DNA were amplified by the polymerase chain reaction（ PCR）. The capacity of its Al tolerance was identified by the growth in solid and liquid GM media with different Al. The residual active Al content in supernatant was measured through inductively coupled plasma-atomic emission spectrometry（ ICP-AES）. Results The strain was identified as C. podzolicus through the sequences analysis of D1 / D2 region of 26 S r DNA and ITS（ Internal transcribed spacer,ITS） region. The strain is able to grow on the GM medium containing 100 mmol / L Al3 ＋. The residual active Al content determined in culture solution suggested that attachment of Al on the surface might be one of the reasons for its Al resistance. Conclusion This report is the first demonstration that C. podzolicus is tolerant to Al. The highly Al-tolerant yeast strain is potential to elucidate the mechanisms of Al tolerance and clone Al-tolerant genes.