4株南极真菌的形态学和分子鉴定及其中3株的蛋白磷酸酶、脂肪酸成分分析

Antarctic fungi: molecular identification,analysis of their protein phosphatase and fatty acid

由于极地独特的地理、气候及环境特点,使得极地微生物及其代谢产物具有新颖性与多样性。采用3种选择性培养基的稀释平板涂布法,从南极普里兹湾海洋沉积物中分离得到4株真菌菌株,经过形态学、18s r DNA-ITS序列分析,分别鉴定为隐球酵母Cryptococcus sp.NJF1、曲霉Aspergillus sp.NJF3、枝孢霉Cladosporium sp.NJF4和Cladosporium sp.NJF6;对其中的曲霉NJF3、枝孢霉NJF4和NJF6等3株真菌开展了蛋白磷酸酶含量和大田软海绵酸OA对该酶的抑制作用测试,并分析了菌株提取物中的脂肪酸成分。结果显示:NJF3、NJF4和NJF6有很好的蛋白磷酸酶活性,以蛋白磷酸酶-PP为外标,测定酶含量分别为0.732 2 U·g-1、0.678 U·g-1和1.229 2 U·g-1,且100 n M OA对NJF3和NJF4蛋白磷酸酶有一定抑制作用,而NJF6需要200 n M OA才可以轻微抑制其蛋白磷酸酶活性;3株真菌的脂肪酸成分以油酸为主,相对含量分别达到32.4%、37.2%、40.1%,而NJF4和NJF6还含有较高含量的亚油酸,相对含量分别达到27.3%、29.8%。本研究可为下一步开展菌株的酶、天然代谢产物研究奠定基础。

Due to the unique characteristics of geography,climate and environment,the microorganisms in polar area and their metabolites show high diversity and novelty. 4 fungus strains were isolated from an Antarctic marine sediment sample collected in Prydz Bay by dilution-plate method with 3 selective culture mediums. They were identified as Cryptococcus sp. NJF1,Aspergillus sp. NJF 3,Cladosporium sp. NJF4 and Cladosporium sp. NJF6 with morphological and 18 s r DNA-ITS sequence analysis. Assay of protein phosphatase content and inhibitory effect of okadaic acid（OA） to the protein phosphatase,as well as fatty acid analysis of Aspergillus sp. NJF3,Cladosporium sp. NJF4 and NJF6 were carried out. Good results of protein phosphatase were obtained,and by comparison with the λ-PP standard,the protein phosphatase content reached 0. 7322 U · g-1,0. 678 U · g-1 and 1. 2292 U · g-1 in NJF3,NJF4 and NJF6,respectively. The protein phosphatase in NJF3 and NJF4 were weakly inhibited by 100 nM OA,while that in NJF6 could only be slightly inhibited by 200 n M OA. Oleic acid was the major fatty acid in these three fungi strains with relative content of 32. 4%,37. 2% and 40. 1%,respectively,and there was also high content of linoleic acid at 27. 3% and 29. 8% in NJF4 and NJF6. This study laid a foundation for the future investigation on the enzyme and natural metabolites of these fungi strains.