Worldwide, lava caves host colorful microbial mats. However, little is known about the diversity of these microorganisms, or what role they may play in the subsurface ecosystem. White and yellow microbial mats were collected from four lava caves each on the Azorean island of Terceira and the Big Island of Hawai'i, to compare the bacterial diversity found in lava caves from two widely separated archipelagos in two different oceans at different latitudes. Scanning electron microscopy of mat samples showed striking similarities between Terceira and Hawai'ian microbial morphologies. 16S rRNA gene clone libraries were constructed to determine the diversity within these lava caves. Fifteen bacterial phyla were found across the samples, with more Actinobacteria clones in Hawai'ian communities and greater numbers of Acidobacteria clones in Terceira communities. Bacterial diversity in the subsurface was correlated with a set of factors. Geographical location was the major contributor to differences in community composition (at the OTU level), together with differences in the amounts of organic carbon, nitrogen and copper available in the lava rock that forms the cave. These results reveal, for the first time, the similarity among the extensive bacterial diversity found in lava caves in two geographically separate locations and contribute to the current debate on the nature of microbial biogeography.

中文翻译：

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亚速尔群岛和夏威夷熔岩洞穴微生物垫中细菌多样性的比较

在世界范围内，熔岩洞穴拥有色彩缤纷的微生物垫。然而，人们对这些微生物的多样性以及它们在地下生态系统中可能发挥的作用知之甚少。从亚速尔群岛特塞拉岛和夏威夷大岛的四个熔岩洞穴中收集了白色和黄色的微生物垫，以比较在不同纬度的两个不同海洋中两个相距很远的群岛的熔岩洞穴中发现的细菌多样性。垫样品的扫描电子显微镜显示 Terceira 和夏威夷微生物形态之间惊人的相似性。构建了 16S rRNA 基因克隆文库以确定这些熔岩洞穴内的多样性。在样本中发现了 15 个细菌门，在夏威夷有更多的放线菌克隆 ian 社区和 Terceira 社区中更多的酸杆菌克隆。地下的细菌多样性与一系列因素相关。地理位置是造成群落组成差异的主要因素（在 OTU 级别），以及形成洞穴的熔岩中可用的有机碳、氮和铜含量的差异。这些结果首次揭示了在两个地理上不同位置的熔岩洞穴中发现的广泛细菌多样性之间的相似性，并有助于当前关于微生物生物地理学性质的争论。以及形成洞穴的熔岩中可用的有机碳、氮和铜含量的差异。这些结果首次揭示了在两个地理位置不同的熔岩洞穴中发现的广泛细菌多样性之间的相似性，并促成了目前关于微生物生物地理学性质的争论。以及形成洞穴的熔岩中可用的有机碳、氮和铜含量的差异。这些结果首次揭示了在两个地理位置不同的熔岩洞穴中发现的广泛细菌多样性之间的相似性，并促成了目前关于微生物生物地理学性质的争论。