Abstract—

The cultures assigned to the genus Thermoanaerobacterium according to the partial sequencing of the 16S rRNA gene were isolated on CM3 and GS2 media at 55°С from two laboratory methanogenic thermophilic cellulolytic microbial communities producing biogas from various paper substrates. Cellulolytic activity was shown for three isolates grown on solid and in liquid media with microcrystalline cellulose and filter paper as the only substrates. In order to compare the phylogenetic relations between these isolates and the reference strains of T. thermosaccharolyticum (DSM 571, M0795, and TG57), it was shown that the isolates I2 and I3 belonged to one cluster, whereas the I1 isolate formed a separate branch on the phylogenetic tree. A unique feature of isolate I2 is the formation of an insoluble yellow affinity substance (YAS), which is usually produced by certain anaerobic cellulolytic bacteria, such as Clostridium thermocellum; it is considered a binding component between the cellulase enzyme and its substrate, cellulose. Our results confirmed that cellulolytic T. thermosaccharolyticum strains predominated among cellulose-degrading bacteria within the thermophilic microbial communities converting the paper substrates into biogas. Although the type strain T. thermosaccharolyticum DSM 571 lacks cellulolytic capacity, our results are consistent with the recent data on the ability of several T. thermosaccharolyticum strains to degrade cellulose.

中文翻译：

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从嗜热产甲烷微生物群落中分离降解纤维素的热厌氧菌菌株。

摘要—

根据15S的16S rRNA基因的部分测序，将属于热厌氧菌属的培养物在CM3和GS2培养基上于55°C从两个实验室产甲烷的嗜热纤维素分解微生物群落中分离，这些微生物从各种纸质底物中产生沼气。对于在固态和液态培养基中生长的三种分离物（以微晶纤维素和滤纸为唯一底物）显示了纤维素分解活性。为了比较这些分离株与热解糖热菌的参考菌株之间的系统发育关系（DSM 571，M0795和TG57），已显示分离株I2和I3属于一个簇，而I1分离株在系统树上形成了单独的分支。分离物I2的一个独特特征是形成了不溶性黄色亲和力物质（YAS），通常由某些厌氧性纤维素分解细菌（如热纤梭菌）产生。它被认为是纤维素酶及其底物纤维素之间的结合成分。我们的结果证实，在嗜热微生物群落中，降解纤维素的细菌中，分解纤维素的嗜热链球菌菌株占主导地位，从而将纸质底物转化为沼气。虽然类型菌株T.thermosaccharolyticumDSM 571缺乏纤维素分解能力，我们的结果与关于几种热解糖衣杆菌菌株降解纤维素的能力的最新数据一致。