Formation of Fatty Acid-degrading, anaerobic granules by defined species
Formation of Fatty Acid-degrading, anaerobic granules by defined species
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由特定物种形成脂肪酸降解、厌氧颗粒
DOI：
10.1128/aem.62.6.2037-2044.1996
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发表时间：
1996
影响因子：
4.4
通讯作者：
J. Zeikus
中科院分区：
文献类型：
--
作者：
W. Wu;M. Jain;J. Zeikus
在与产甲烷菌单氧共培养的条件下，在丁酸盐上培养出一种形成内孢子的丁酸盐降解细菌（菌株BH）。以甲酸甲烷菌为产甲烷菌伴生时，培养物形成致密的聚集体，而以黄盖特甲烷菌伴生时，培养物呈浑浊状。相反，一种降解丙酸的柠檬形细菌（菌株PT）不与甲酸甲烷杆菌形成聚集体，除非在培养中也含有一种降解醋酸盐的甲烷菌。在实验室规模的上流式反应器中，在35（℃）的温度下，用含有乙酸、丙酸和丁酸盐混合物的培养基，通过确定的甲酸甲烷杆菌T1N、Methanosaeta sp.菌株M7、Methanosarcina mazei T18、丙酸降解菌株PT和丁酸降解菌株BH的培养物形成脂肪酸降解产甲烷颗粒。这些颗粒对乙酸、丙酸和丁酸的最大底物转化率分别为43、9和17 mmol/g（干重）/天。颗粒的平均尺寸约为1mm。电镜观察发现，颗粒中分散有甲酸甲烷杆菌、甲烷菌、丁酸降解菌和丙酸降解菌的细胞。mazei甲烷藻以自身细胞的聚集体形式存在于颗粒内部，与颗粒的体积有关。不同种类的相互作用在聚集体的形成和颗粒的形成讨论了有关聚合物的细胞表面的形成。
An endospore-forming, butyrate-degrading bacterium (strain BH) was grown on butyrate in monoxenic coculture with a methanogen. The culture formed dense aggregates when Methanobacterium formicicum was the methanogenic partner, but the culture was turbid when Methanospirillum hungatei was the partner. In contrast, a propionate-degrading, lemon-shaped bacterium (strain PT) did not form aggregates with Methanobacterium formicicum unless an acetate-degrading Methanosaeta sp. was also included in the culture. Fatty acid-degrading methanogenic granules were formed in a laboratory-scale upflow reactor at 35(deg)C fed with a medium containing a mixture of acetate, propionate, and butyrate by using defined cultures of Methanobacterium formicicum T1N, Methanosaeta sp. strain M7, Methanosarcina mazei T18, propionate-degrading strain PT, and butyrate-degrading strain BH. The maximum substrate conversion rates of these granules for acetate, propionate, and butyrate were 43, 9, and 17 mmol/g (dry weight)/day, respectively. The average size of the granules was about 1 mm. Electron microscopic observation of the granules revealed that the cells of Methanobacterium formicicum, Methanosaeta sp., butyrate-degrading, and propionate-degrading bacteria were dispersed in the granules. Methanosarcina mazei existed inside the granules as aggregates of its own cells, which were associated with the bulk of the granules. The interaction of different species in aggregate formation and granule formation is discussed in relation to polymer formation of the cell surface.