Temperature effects on structure and function of the methanogenic microbial communities in two paddy soils and one desert soil
Temperature effects on structure and function of the methanogenic microbial communities in two paddy soils and one desert soil
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DOI：
10.1016/j.soilbio.2018.06.024
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发表时间：
2018-09-01
影响因子：
9.7
通讯作者：
Conrad, Ralf
中科院分区：
文献类型：
--
作者：
Liu, Pengfei;Klose, Melanie;Conrad, Ralf
温度是调节温室气体CH4产生的一个重要因素。先前对意大利温带产甲烷水稻土的研究表明，当温度升高到高于约40 ℃时，土壤微生物群落的结构和功能发生急剧变化。由于产甲烷古菌在湿地和高地土壤中都普遍存在，我们想知道其他土壤是否会有类似的行为。因此，我们比较了水稻土从意大利和菲律宾，其中有不同的微生物群落结构，并调查了沙漠土壤从犹他州（美国），表示洪水后的甲烷生产。我们培养这些土壤在缺氧条件下，在三个不同的温度。我们确定了产甲烷古菌和细菌群落的组成，丰度和功能，分别使用Illumina HiSeq测序，qPCR和活性和稳定同位素分馏分析。在中等温度下（25摄氏度和35摄氏度），甲烷总是由乙酸裂解和氢营养甲烷的组合产生。然而，在升高的温度（45摄氏度）的组合acetochlastic和hydrogenotrophic产甲烷仅保持在菲律宾的土壤中，其中包含hydrogenotrophic（甲烷杆菌目，甲烷胞菌目，甲烷菌科）和acetochlastic（甲烷菌科，甲烷菌科）产甲烷类群在这些条件下。相比之下，在意大利和犹他州的土壤中，甲烷生产在45摄氏度发生氢营养产甲烷，和古菌群落缺乏acetoclastic产甲烷菌。乙酸盐反而被嗜热嗜热菌科（可能还有太阳杆菌科）的附属物种氧化，这些物种与氢营养型甲烷细胞目和甲烷细菌目互养相连。研究结果表明，不同土壤在高温和中温条件下表现出不同的产甲烷古菌和细菌群落结构和功能。菲律宾水稻土中的乙酸分解产甲烷菌能够耐受高温，而意大利水稻土和犹他州沙漠土壤中的产甲烷菌则不能。相反，互养乙酸氧化允许有机物完全降解为CH 4和CO 2。
Temperature is an important factor regulating the production of the greenhouse gas CH4. Previous studies of temperate methanogenic paddy soils from Italy showed that structure and function of the soil microbial communities changed drastically when temperature was increased to values higher than about 40 degrees C. Since methanogenic archaea are ubiquitous in both wetland and upland soils, we wondered whether other soils would behave similarly. Therefore, we compared paddy soils from Italy and the Philippines, which have different microbial community structures, and also investigated a desert soil from Utah (USA), which expressed CH4 production upon flooding. We incubated these soils under anoxic conditions at three different temperatures. We determined composition, abundance and function of the methanogenic archaeal and bacterial communities using illumina HiSeq sequencing, qPCR and analysis of activity and stable isotope fractionation, respectively. At moderate temperatures (25 degrees C and 35 degrees C), CH4 was always produced by a combination of acetoclastic and hydrogenotrophic methanogenesis. However, at elevated temperature (45 degrees C) the combination of acetoclastic and hydrogenotrophic methanogenesis was only maintained in the Philippines soil, which contained hydrogenotrophic (Methanobacteriales, Methanocellales, Methanosarcinaceae) and acetoclastic (Methanosarcinaceae, Methanotrichaceae) methanogenic taxa under these conditions. In Italian and Utah soil by contrast, CH4 production at 45 degrees C occurred by hydrogenotrophic methanogenesis, and the archaeal community was lacking acetoclastic methanogens. Acetate was instead oxidized by Thermocataerobacteraceae (and perhaps Heliobacteriaceae) affiliated species which were syntrophically connected to hydrogenotrophic Methanocellales and Methanobacteriales. Our results showed that the different soils exhibited different structures and functions of the methanogenic archaeal and bacterial communities at elevated versus moderate temperatures. While acetoclastic methanogens in the Philippines paddy soil were able to tolerate elevated temperatures, those in Italian paddy soil and Utah desert soil were not. Instead, syntrophic acetate oxidation allowed the complete degradation of organic matter to CH4 and CO2.