红树植物根内生放线菌的分离鉴定及其生理活性的评价

采集海南文昌清澜港头苑村红树林保护区的18种红树植物和3种半红树植物的根部样品，用1／10ATCC172培养基共分离到138株内生放线菌。经初步鉴定，分离到的138株内生放线菌分别属于继生菌属、小单胞菌属和链霉菌属3个属。对分离到的内生放线菌进行体外细胞毒活性和抗菌活性检测，结果表明，对肝癌SMMC-7721细胞有细胞毒活性的菌株有40株，抗MRSA活性的菌株有27株，所有测试菌株均未检测到抗白色念珠菌活性。对88株菌进行耐盐性检测，77株菌表现出耐盐或嗜盐特征，其中2株最高耐盐质量浓度ρ（NaCl）=150g·L-1，54株菌可在含有P（NaCl）=33g·L-1的培养基上生长良好。

Identification and evaluation of physiologically active root endophytic actinomycetes from mangrove plants in Hainan Province

A total of 138 root endophytic actinomycete strains were successfully isolated using 1/10ATCC 172 medium from the roots of 18 mangrove plants and 3 semi-mangrove plants in Hainan Province. Analysis of 16S rRNA gene sequences of these isolates showed that the isolates belonged to members of the genera Jishengella, Micromonospora and Streptomycetes. Bioactivity tests were carried out on all the isolated endophytic actinomycete fermentation liquids. Of all the isolates forty strains showed citotoxities to hepatocarcinoma cell line SMMC-7721 cell, and twenty seven strains were active against methicillin-resistant Staphylococcus aureus 9551 （MRSA）. The strains isolated from the mangroves showed no bioactivity against Candida albicans ATCC 10231. Sodium chloride tolerance test for 88 isolates indicated that 77 isolates were halo-tolerant or halophilic, 2 isolates of which exhibited the highest tolerance to p（NaCI） = 150 g ·L-1 and 54 isolates grew well on the medium containing p （NaCl） =33 g ·L-1.