INTERMEDIARY METABOLISM IN METHANOGENIC PADDY SOIL AND THE INFLUENCE OF TEMPERATURE
INTERMEDIARY METABOLISM IN METHANOGENIC PADDY SOIL AND THE INFLUENCE OF TEMPERATURE
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DOI：
10.1016/0168-6496(95)00042-9
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发表时间：
1995-10-01
影响因子：
4.2
通讯作者：
CONRAD, R
中科院分区：
文献类型：
--
作者：
CHIN, KJ;CONRAD, R
通过低温（15 ℃）和高温（30 ℃）泥浆培养试验，研究了产甲烷稻田土壤的中间代谢。向低温的转变、通过添加CHCl 3抑制甲烷生成或通过增加H-2分压（0.2巴）抑制H-2产生互养细菌都导致代谢中间体的积累。温度变化至15 ° C导致CH 4生产速率以及H-2和CO2分压的降低，并导致乙酸盐、丙酸盐、己酸盐、乳酸盐和异丙醇的瞬时积累。氯仿在15 ℃和30 ℃下抑制甲烷生成，并导致乙酸盐、H-2、丙酸盐、己酸盐、乳酸盐和异丙醇的积累。添加H-2导致在两个温度下的丙酸盐，己酸盐，乳酸盐，甲酸盐和异丙醇的积累。添加的H-2与CO2一起被消耗，在30 ℃时主要被甲烷生成消耗，但在15 ℃时主要被同型乙酸生成消耗。温度的降低引起的增加（较少的放能）的吉布斯自由能的H-2生产的反应，这是大于H-2消耗的反应。氯仿的加入，以及更多的H-2的加入，也导致了产生H-2的反应的吉布斯自由能的增加，从而解释了为什么检测到的中间体确实积累了。当甲烷生成被氯仿抑制时积累的代谢产物很大程度上（76-108%）占缺失的CH 4。通过乙酸盐的碳流贡献了流向CH 4的总碳流的79-83%。积累的中间体的相对量的比较表明，H-2生产反应（推测互养细菌）是更敏感的低温比H-2消耗反应，和H-2消耗甲烷更敏感比H-2消耗同型乙酸。
The intermediary metabolism in methanogenic rice paddy soil was studied by slurry incubation experiments at low (15 degrees C) and high (30 degrees C) temperatures. A shift to a low temperature, inhibition of methanogenesis by the addition of CHCl3, or inhibition of H-2-producing syntrophic bacteria by increased partial pressures of H-2 (0.2 bar) all resulted in the accumulation of metabolic intermediates. The temperature shift to 15 degrees C resulted in a decrease of the CH4 production rate and of the H-2 and CO2 partial pressures, and resulted; in the transient accumulation of acetate, propionate, caproate, lactate, and iso-propanol. Chloroform inhibited methanogenesis and resulted in the accumulation of acetate, H-2, propionate, caproate, lactate, and iso-propanol at both 15 degrees C and 30 degrees C. Addition of H-2 resulted in the accumulation of propionate, caproate, lactate, formate and iso-propanol at both temperatures. The added H-2 was consumed, together with CO2, mainly by methanogenesis at 30 degrees C, but mainly by homoacetogenesis at 15 degrees C. A decrease in temperature caused an increase (less exergonic) of the Gibbs free energy of the H-2-producing reactions that was larger than that of the H-2-consuming reactions. Addition of chloroform, and even more so of H-2, also resulted in increased Gibbs free energies of H-2-producing reactions, thus explaining why the intermediates detected did accumulate. The metabolites that accumulated when methanogenesis was inhibited by chloroform largely (76-108%) accounted for the missing CH4. Carbon flow through acetate contributed 79-83% of the total carbon flow to CH4. Comparison of the relative amounts of accumulated intermediates indicates that the H-2-producing reactions (presumably syntrophic bacteria) were more sensitive to low temperature than the H-2-consuming reactions, and that H-2 consumption by methanogenesis was more sensitive than H-2 consumption by homoacetogenesis.