死海嗜盐耐盐放线菌分离方法研究

Study on method of actinomycetes isolation from Dead Sea

【目的】探讨死海高盐地区分离嗜盐耐盐放线菌的最佳方法,为高盐地区放线菌的分离提供理论依据。【方法】采用物理方法(微波)、化学方法(加入孢子活化剂)、富集培养法及3种方法的组合共计9种方法,对死海地区土样进行预处理,然后在3种复合盐含量(150,225,300g/L)及不同培养基(ISP5、CMKA、HV)条件下,研究复合盐含量及培养基对分离放线菌种类和数量的影响,并筛选嗜盐耐盐放线菌的最佳分离方法。【结果】①在3种培养基上,对土样采用9种方法进行预处理,其中物理+化学方法处理后分离的放线菌种类明显高于其他预处理方法;富集培养法预处理土样分离的放线菌种类明显较少。②不同复合盐条件下,3种培养基分离的放线菌种类和数量表现为CMKA>HV>ISP5。③不同培养基上,3种复合盐条件下分离的放线菌种类总体上表现为300g/L>225g/L>150g/L,分离的放线菌数量总体表现为150g/L>225g/L>300g/L。【结论】比较筛选得到了分离死海高盐地区嗜盐耐盐放线菌的最佳方法,即土样经微波与化学孢子活化剂共同处理后,在含225g/L复合盐的CMKA培养基上培养。

【Objective】 The study was to explore an optimal method of actinomycetes isolation from Dead Sea,so as to improve the isolation of actinomycetes from soil with high salt concentration.【Method】 Actinomycete counts and numbers of actinomycete species were analyzed from three aspects：sample pre-treatments,cultural media and salt concentrations of media.Nine pre-treatments,including chemical,physical and accumulation culture methods,three types of cultural media,ISP5,HV and CMKA,and three salt concentrations of each medium（150,225,300 g/L） were tested.【Result】 ① For sample pre-treatments,numbers of actinomycete species isolated from the chemical＋physical pre-treated sample were apparently higher than that from others,whereas species numbers isolated from the accumulation cultured sample were the least on three media.② With all of the three salt concentrations,numbers of actinomycete species and actinomycete counts isolated from soil samples both led a trend：CMKA〉HV〉ISP5.③ On three media,numbers of actinomycete species isolated from samples showed：300 g/L〉225 g/L〉150 g/L,while actinomycete counts showed：150 g/L〉225 g/L〉300 g/L.【Conclusion】 Pretreating soil samples with chemical＋physical method and using 225 g/L salt concentration CMKA medium is the best way to isolate actinomycetes from Dead Sea.