Pattern of non-methanogenic and methanogenic degradation of cellulose in anoxic rice field soil
Pattern of non-methanogenic and methanogenic degradation of cellulose in anoxic rice field soil
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DOI：
10.1111/j.1574-6941.2000.tb00674.x
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发表时间：
2000-01-01
影响因子：
4.2
通讯作者：
Conrad, R
中科院分区：
文献类型：
--
作者：
Chidthaisong, A;Conrad, R
稻田土壤在淹水时变成缺氧。然后通过硝酸盐、三价铁、硫酸盐的顺序还原以及最后通过甲烷生成来完成有机物质（例如纤维素）到气态产物的完全矿化。因此，[U-C-14]纤维素的厌氧营业额进行了研究，在新鲜的，非产甲烷和预培养，产甲烷泥浆的意大利稻田土壤。在由空气干燥的土壤新鲜制备的缺氧土壤泥浆中，[U-C-14]纤维素以3：1的比例转化为（CO2）-C-14和（CH 4）-C-14。另一方面，在厌氧条件下预培养45天的产甲烷土壤泥浆中，[U-C-14]纤维素以1：1的比例转化为（CO2）-C-14和（CH 4）-C-14。在新鲜土壤和产甲烷土壤中，纤维素降解周转时间（7-14天）差异不显著（P > 0.05）。氯仿除了废除CH 4生产，但只有轻微（30%）抑制纤维素降解在新鲜和产甲烷土壤。在这两种土壤条件下，[C-14]醋酸盐是唯一检测到的标记中间体。在新鲜和产甲烷土壤泥浆中，最多24%的应用放射性瞬时累积为[C-14]乙酸盐。然而，当甲烷被抑制氯仿，46%和66%的应用放射性回收为[C-14]乙酸在新鲜和产甲烷土壤中，分别。在与[U-C-14]纤维素孵育期间，仅非放射性丙酸盐积累，特别是在氯仿存在下，表明丙酸盐是由纤维素以外的底物产生的。(C)2000年，欧洲微生物学会联合会。由Elsevier Science B. V.出版，版权所有。
Rice field soils turn anoxic upon flooding. The complete mineralization of organic matter, e.g. cellulose, to gaseous products is then accomplished by the sequential reduction of nitrate, ferric iron, sulfate and finally by methanogenesis. Therefore, the anaerobic turnover of [U-C-14]cellulose was investigated in fresh, non-methanogenic and in preincubated, methanogenic slurries of Italian rice field soil. In anoxic soil slurries freshly prepared from air-dried soil [U-C-14]cellulose was converted to (CO2)-C-14 and (CH4)-C-14 in a ratio of 3:1. In methanogenic soil slurries, on the other hand, which had been preincubated for 45 days under anaerobic conditions, [U-C-14]cellulose was converted to (CO2)-C-14 and (CH4)-C-14 in the ratio of 1:1. The turnover times (7-14 days) of cellulose degradation were not significantly different (P > 0.05) in fresh and methanogenic soil. Chloroform addition abolished CH4 production, but only slightly (30%) inhibited cellulose degradation in both fresh and methanogenic soil. Under both soil conditions, [C-14]acetate was the only labeled intermediate detected. A maximum of 24% of the applied radioactivity was transiently accumulated as [C-14]acetate in both fresh and methanogenic soil slurries. However, when methanogenesis was inhibited by chloroform, 46% and 66% of the applied radioactivity were recovered as [C-14]acetate in fresh and methanogenic soil, respectively. Only non-radioactive propionate accumulated during the incubation with [U-C-14]cellulose, especially in the presence of chloroform, indicating that propionate was produced from substrates other than cellulose. (C) 2000 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.