Temporal changes in archaeal diversity and chemistry in a mid-ocean ridge subseafloor habitat
Temporal changes in archaeal diversity and chemistry in a mid-ocean ridge subseafloor habitat
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DOI：
10.1128/aem.68.4.1585-1594.2002
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发表时间：
2002-04-01
影响因子：
4.4
通讯作者：
Baross, JA
中科院分区：
文献类型：
--
作者：
Huber, JA;Butterfield, DA;Baross, JA
使用PCR扩增的16S rRNA基因序列分析和最大可能数（MPN）培养技术，针对超嗜热菌喷口流体古菌多样性的时间变化进行了研究。为了确定温度和海底流体的化学特性的变化如何影响微生物群落，我们进行了分子系统发育和化学分析扩散流喷口流体从一个网站后不久，在1998年火山爆发，并再次在1999年和2000年。古细菌种群被分为颗粒附着（>3微米直径的细胞）和自由生活的部分，以测试与活跃的热液系统相关的海底下微生物适应的生活方式，包括附着在固体表面和形成生物膜的假设。为了区分夹带的海水古菌和本地海底下微生物群落，还检查了背景海水样本，发现仅由I组Crenarchaeota和H组Euryarchaeota组成，这两种细菌也存在于喷口流体中。土著海底下古菌群落包括与嗜中温和超嗜热甲烷球菌有关的克隆，以及许多未培养的真古菌，其中一些已在其他喷口环境中发现。颗粒附着部分始终表现出更大的多样性比自由生活部分。流体和MPN计数表明，虽然可培养的超嗜热菌占总微生物群落的不到1%，但新喷发地点的海底下确实支持超嗜热微生物群落。海底下混合程度的温度和化学指标似乎是影响群落多样性的最重要的环境参数，很明显，流体温度的降低与海水夹带的增加、热液化学物种浓度的降低以及海水古生物序列发生率的增加有关。
The temporal variation in archaeal diversity in vent fluids from a midocean ridge subseafloor habitat was examined using PCR-amplified 16S rRNA gene sequence analysis and most-probable-number (MPN) cultivation techniques targeting hyperthermophiles. To determine how variations in temperature and chemical characteristics of subseafloor fluids affect the microbial communities, we performed molecular phylogenetic and chemical analyses on diffuse-flow vent fluids from one site shortly after a volcanic eruption in 1998 and again in 1999 and 2000. The archaeal population was divided into particle-attached (>3-mum-diameter cells) and free-living fractions to test the hypothesis that subseafloor microorganisms associated with active hydrothermal systems are adapted for a lifestyle that involves attachment to solid surfaces and formation of biofilms. To delineate between entrained seawater archaea and the indigenous subseafloor microbial community, a background seawater sample was also examined and found to consist only of Group I Crenarchaeota and Group H Euryarchaeota, both of which were also present in vent fluids. The indigenous subseafloor archaeal community consisted of clones related to both mesophilic and hyperthermophilic Methanococcales, as well as many uncultured Eutyarchaeota, some of which have been identified in other vent environments. The particle-attached fraction consistently showed greater diversity than the free-living fraction. The fluid and MPN counts indicate that while culturable hyperthermophiles represent less than 1% of the total microbial community, the subseafloor at new eruption sites does support a hyperthermophilic microbial community. The temperature and chemical indicators of the degree of subseafloor mixing appear to be the most important environmental parameters affecting community diversity, and it is apparent that decreasing fluid temperatures correlated with increased entrainment of seawater, decreased concentrations of hydrothermal chemical species, and increased incidence of seawater archaeal sequences.