高温海藻床中微生物的分离鉴定及其耐热、耐盐特性研究

Isolation and identification of microorganisms from high temperature seaweed beds and study on the characteristics of thermo and salt tolerances

【目的】对印度洋卡利安达岛海洋热泉周边的高温海藻床中的微生物进行分离培养和16S rDNA种属鉴定,并研究其耐热和耐盐特性。【方法】采集海藻床中马尾藻、沉积物和海水样品,采用MGYTC培养基,分别于55°C和30°C对样品中的微生物进行培养和分离纯化;采用16S rDNA鉴定种属并构建进化树;研究培养温度和盐度对几种菌株生长的影响。【结果】共获得4个纲、9个属的12种菌株,与已知种属的相似度高于98%。芽孢杆菌纲嗜热放线菌科2个属的菌株和芽孢杆菌属菌株在55°C培养时获得,为嗜热菌株;其中高温放线糖莱斯菌(Laceyella sacchari)和热噬淀粉芽孢杆菌(Bacillus thermoamylovorans)可以在0 90的盐度范围生长。γ-变形菌纲希瓦氏属的Shewanella upenei、Shewanella algidipiscicola和鲍希瓦氏菌(Shewanella haliotis)可适应30°C 55°C的生长环境。【结论】研究获得的菌株,具有耐热、耐盐或对温度适应范围广等特性,有望成为生物技术领域的新资源;分离获得的Tepidibacter formicigenes,深海微小杆菌(Exiguobacterium profundum)和魔鬼弧菌(Vibrio diabolicus)曾被报道来源于深海热液区,这对于阐明海洋热泉与深海热液环境的内在联系提供了参考。

[Objective] Microorganisms from high temperature seaweed beds on Kalianda Island of Indian Ocean were isolated, cultivated, and identified based on 16S rDNA sequences. Study on characteristics of thermo and salt tolerances of selected isolates were also carried on. [Methods] Samples of alga Sargasso sp., sediment and water from seaweed beds were collected. Using MGYTC medium, microorganisms from the samples were cultivated and purified at 55 °C and 30 °C, respectively. Species identification was determined based on 16S rDNA sequences and phylogenetic tree was built afterwards. Effects of culture temperature and salinity on bacterial growth were determined. [Results] A total of 12 strains belonged to four classes and nine genuses were obtained, and the maximum similarities were higher than 98% with known species. Two strains belonged to different genus of thermophilic actinomycetes, and two Bacillus strains obtained at 55 °C were thermophile. Laceyella sacchari and Bacillus thermoamylovorans can survive at the range of 0–90 salinity. Shewanella upenei, Shewanella algidipiscicola and Shewanella haliotis belonged to γ-Proteobacteria could grow at the temperature of 30 °C–55 °C. [Conclusion] The strains obtained had features of thermo and salt tolerances, or adaptability to wide temperature range, which were expected to be new resources in biotechnology field. The isolates of Tepidibacter formicigenes, Exiguobacterium profundum and Vibrio diabolicus had been originally reported from the deep-sea hydrothermal area, suggesting the internal relations of marine hot spring system and deep-sea hydrothermal environment.