Effect of dilution rate on metabolic pathway shift between aceticlastic and nonaceticlastic methanogenesis in chemostat cultivation
Effect of dilution rate on metabolic pathway shift between aceticlastic and nonaceticlastic methanogenesis in chemostat cultivation
复制标题
DOI：
10.1128/aem.70.7.4048-4052.2004
复制
发表时间：
2004-07-01
影响因子：
4.4
通讯作者：
Kida, K
中科院分区：
文献类型：
--
作者：
Shigematsu, T;Tang, YQ;Kida, K
利用13 C标记的乙酸盐研究了产甲烷菌群在乙酸盐恒化器中稀释率为0.025和0.6d（-1）时的乙酸盐转化途径，并对产生的CH 4和CO2进行了气相色谱-质谱（GC-MS）分析。在低稀释率下，乙酸盐氧化互养体和氢营养型产甲烷菌的nonaceticaceticaceticum互养氧化被认为占据了总产甲烷的主要途径（约62%至90%）。与此相反，乙酸裂解乙酸的乙酸产甲烷菌被认为是占据了主要途径（约95至99%），在总的甲烷在高稀释率。甲基辅酶M还原酶基因（mcrA）的转录本的系统发育分析证实，一个显着数量的转录本属Methanoculleus（氢营养型产甲烷菌）和甲烷八叠球菌（醋酸甲烷菌）存在于恒化器中的低和高稀释率，分别。在先前的研究中占主导地位的Methanosaeta属（乙酸杆菌产甲烷菌）的mcrA转录本（T. Shigematsu，Y.唐，H.川口，K.二宫、木岛、T.小林、S. Morimura和K. Kida，J. Biosci. Bioeng. 96：547-558，2003），由于所用引物的有限覆盖度，在两种稀释率下均检测不佳。这些结果表明，稀释率可能导致乙酸盐进料恒化器中乙酸盐转化为甲烷的主要途径的转变。
Acetate conversion pathways of methanogenic consortia in acetate-fed chemostats at dilution rates of 0.025 and 0.6 day(-1) were investigated by using 13 C-labeled acetates, followed by gas chromatography-mass spectrometry (GC-MS) analysis of the CH4 and CO2 produced. Nonaceticlastic syntrophic oxidation by acetate-oxidizing syntrophs and hydrogenotrophic methanogens was suggested to occupy a primary pathway (approximately 62 to 90%) in total methanogenesis at the low dilution rate. In contrast, aceticlastic cleavage of acetate by aceticlastic methanogens was suggested to occupy a primary pathway (approximately 95 to 99%) in total methanogenesis at the high dilution rate. Phylogenetic analyses of transcripts of the methyl coenzyme M reductase gene (mcrA) confirmed that a significant number of transcripts of the genera Methanoculleus (hydrogenotrophic methanogens) and Methanosarcina (aceticlastic methanogens) were present in the chemostats at the low and high dilution rates, respectively. The mcrA transcripts of the genus Methanosaeta (aceticlastic methanogens), which dominated the population in a previous study (T. Shigematsu, Y. Tang, H. Kawaguchi, K. Ninomiya, J. Kijima, T. Kobayashi, S. Morimura, and K. Kida, J. Biosci. Bioeng. 96:547-558, 2003), were poorly detected at both dilution rates due to the limited coverage of the primers used. These results demonstrated that the dilution rate could cause a shift in the primary pathway of acetate conversion to methane in acetate-fed chemostats.