The Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan.
Syst Appl Microbiol. 2013 Sep;36(6):436-43. doi: 10.1016/j.syapm.2013.04.009. Epub 2013 Jun 27.
The diversity of sulfate-reducing prokaryotes (SRPs) and sulfur-oxidizing prokaryotes (SOPs) in freshwater lake ecosystems was investigated by cloning and sequencing of the aprA gene, which encodes for a key enzyme in dissimilatory sulfate reduction and sulfur oxidation. To understand their diversity better, the spatial distribution of aprA genes was investigated in sediments collected from six geographically distant lakes in Antarctica and Japan, including a hypersaline lake for comparison. The microbial community compositions of freshwater sediments and a hypersaline sediment showed notable differences. The clones affiliated with Desulfobacteraceae and Desulfobulbaceae were frequently detected in all freshwater lake sediments. The SOP community was mainly composed of four major phylogenetic groups. One of them formed a monophyletic cluster with a sulfur-oxidizing betaproteobacterium, Sulfuricella denitrificans, but the others were not assigned to specific genera. In addition, the AprA sequences, which were not clearly affiliated to either SRP or SOP lineages, dominated the libraries from four freshwater lake sediments. The results showed the wide distribution of some sulfur-cycle prokaryotes across geographical distances and supported the idea that metabolic flexibility is an important feature for SRP survival in low-sulfate environments.
本研究通过克隆和测序 aprA 基因，调查了淡水湖泊生态系统中硫酸盐还原菌（SRP）和硫氧化菌（SOP）的多样性，该基因编码异化硫酸盐还原和硫氧化的关键酶。为了更好地了解其多样性，本研究调查了 aprA 基因在南极洲和日本的六个地理位置不同的湖泊（包括一个高盐湖泊）沉积物中的空间分布。淡水沉积物和高盐沉积物的微生物群落组成存在显著差异。脱硫杆菌科和脱硫弧菌科的克隆在所有淡水湖泊沉积物中频繁检测到。SOP 群落主要由四个主要的系统发育群组成。其中一个群与硫氧化β-变形菌 Sulfuricella denitrificans 形成单系聚类，但其他群则未被归为特定属。此外，在来自四个淡水湖泊沉积物的文库中，AprA 序列主要由既不属于 SRP 也不属于 SOP 谱系的序列组成。研究结果表明，一些硫循环原核生物在地理距离上广泛分布，并支持代谢灵活性是 SRP 在低硫酸盐环境中生存的重要特征的观点。
