Consortia of low-abundance bacteria drive sulfate reduction-dependent degradation of fermentation products in peat soil microcosms.
Consortia of low-abundance bacteria drive sulfate reduction-dependent degradation of fermentation products in peat soil microcosms.
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DOI：
10.1038/ismej.2016.42
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发表时间：
2016-10
期刊：
影响因子：
--
通讯作者：
Pester M
中科院分区：
文献类型：
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作者：
Hausmann B;Knorr KH;Schreck K;Tringe SG;Glavina Del Rio T;Loy A;Pester M
异化硫酸盐还原泥炭地是持续的一个神秘的硫循环，并有效地与产甲烷降解途径的竞争。在一系列的泥炭土微宇宙培养超过50天，我们确定了细菌财团，响应小，定期添加的个别发酵产物（甲酸，乙酸，丙酸，乳酸或丁酸）的存在或不存在的硫酸盐。在硫酸盐补充下，净硫酸盐周转率（ST）稳步增加到每天16-174 nmol cm-3，几乎完全阻断甲烷生成。16 S rRNA基因和cDNA扩增子测序确定的微生物，其核糖体数量的增加强烈相关的ST。天然丰富（约0.1%估计的基因组丰度）物种水平的操作分类单位（OTU）没有显着的反应硫酸盐。相比之下，低丰度OTU在与丙酸盐、乳酸盐和丁酸盐的孵育中对硫酸盐响应显著。这些OTU包括公认的硫酸盐还原分类群的成员（脱硫孢霉属、脱硫霉属、脱硫菌属、脱硫弧菌属）以及作为未知硫酸盐还原剂或其代谢相互作用配偶体的分类群的成员。大多数响应性OTU显著增加其核糖体含量，但丰度仅微弱增加。响应Desulfosporosinus OTU甚至在50天内保持了恒定的低种群规模，这表明稀有生物圈成员显示活动的新策略。有趣的是，两个OTU的非硫酸盐还原属Telmatosulphyllum（Alphaproteobacteria）显示出强烈的对比偏好硫酸盐在丁酸盐修正的微观世界，证实密切相关的微生物不一定是生态连贯的。我们发现，不同的低丰度微生物财团可以执行泥炭土壤硫酸盐还原，这是一个过程，在这些气候相关的生态系统中施加控制甲烷的产生。
Dissimilatory sulfate reduction in peatlands is sustained by a cryptic sulfur cycle and effectively competes with methanogenic degradation pathways. In a series of peat soil microcosms incubated over 50 days, we identified bacterial consortia that responded to small, periodic additions of individual fermentation products (formate, acetate, propionate, lactate or butyrate) in the presence or absence of sulfate. Under sulfate supplementation, net sulfate turnover (ST) steadily increased to 16–174 nmol cm–3 per day and almost completely blocked methanogenesis. 16S rRNA gene and cDNA amplicon sequencing identified microorganisms whose increases in ribosome numbers strongly correlated to ST. Natively abundant (⩾0.1% estimated genome abundance) species-level operational taxonomic units (OTUs) showed no significant response to sulfate. In contrast, low-abundance OTUs responded significantly to sulfate in incubations with propionate, lactate and butyrate. These OTUs included members of recognized sulfate-reducing taxa (Desulfosporosinus, Desulfopila, Desulfomonile, Desulfovibrio) and also members of taxa that are either yet unknown sulfate reducers or metabolic interaction partners thereof. Most responsive OTUs markedly increased their ribosome content but only weakly increased in abundance. Responsive Desulfosporosinus OTUs even maintained a constantly low population size throughout 50 days, which suggests a novel strategy of rare biosphere members to display activity. Interestingly, two OTUs of the non-sulfate-reducing genus Telmatospirillum (Alphaproteobacteria) showed strongly contrasting preferences towards sulfate in butyrate-amended microcosms, corroborating that closely related microorganisms are not necessarily ecologically coherent. We show that diverse consortia of low-abundance microorganisms can perform peat soil sulfate reduction, a process that exerts control on methane production in these climate-relevant ecosystems.