环磷酸腺苷对太湖界面沉积物可培养细菌多样性的影响

Effects of cyclic adenosine monophosphate on culturable bacterial diversity in the interfacial sediment from Taihu Lake

摘要:

【背景】环境细菌可培养率只有1%，菌间的信息交流是限制培养效率的一个重要原因。细胞间信息传递的“第二信使”——环磷酸腺苷(cAMP)是细菌感知和应对外界变化时使用广泛的物质。【目的】研究cAMP诱导培养下的细菌种群组成变化，以探讨对微生物可培养性的影响，为提高细菌可培养率和菌种资源开发提供参考。【方法】以太湖沉积物为对象，结合高通量测序和分离培养方法解析样品中细菌的多样性。【结果】高通量测序的物种组成分析结果表明，cAMP作用下诱导出60个不同于对照组的OTU (Operational taxonomic unit)，其中显著差异的是变形菌门和拟杆菌门，前者提高4.08%，后者降低3.36%，非常显著差异的是疣微菌门。在属分类水平有8个显著差异的菌属，2个非常显著差异的菌属(气单胞菌属和Trichococcus)。分离培养结果显示，cAMP诱导下CFU (Colony-forming units)提高至1.6倍，诱导培养出微小杆菌属(Exiquobacterium)、微杆菌属(Microbacterium)、热单胞菌属(Thermomonas)、Lacibacter、Pedobacter、Massilia、Kocuria和Arthrobacter。【结论】从高通量结果可知cAMP对变形菌门的菌株生长有显著促进作用，而分离培养结果表明，cAMP提高微小杆菌属、微杆菌属、热单胞菌属、Lacibacter、Pedobacter、Massilia、Kocuria和Arthrobacter的可培养性。

Abstract:

[Background] The culturable rate of environmental bacteria is only about 1%, and the exchange of information among bacteria is an important reason for limiting the rate of culture. Cyclic adenosine monophosphate (cAMP), the second messenger known as intercellular information transmission, is a widely-used substance for bacteria to perceive and respond to the environmental changes. [Objective] The study is aimed to research the changes of bacterial population composition induced by cAMP and investigate the effect on microbial culturability, further to provide reference for improving the culturability of bacteria and the exploration of strain resources. [Methods] Using the high-throughput sequencing and isolation methods to analyze the bacterial diversity in sediment of Taihu Lake. [Results] Results of high-throughput sequencing showed that 60 OTUs (Operational taxonomic units) which were different from the control group appeared. Among them, Proteobacteria and Bacteroides were the significant differences, the former increased by 4.08%, but the latter decreased by 3.36%, and Verrucomicrobia was high significant at p<0.01. At the genus level, there were 8 significant different genera, and 2 (Aeromonas and Trichococcus) very significant statistic differences. Results of isolation and culture showed that, under cAMP’s effect, the population diversity of the bacteria could be increased, with CFU (Colony-forming units) up to 1.6 times as that of the control group, and the bacteria of Exiquobacterium, Microbacterium, Thermomonas, Lacibacter, Pedobacter, Massilia, Kocuria and Arthrobacter were induced. [Conclusion] From high throughput results, cAMP can significantly promote the growth of strains of Proteobacteria, but the results from isolation and culture show that cAMP can improve the culturability of Exiquobacterium, Microbacterium, Thermomonas, Lacibacter, Pedobacter, Massilia, Kocuria and Arthrobacter.