Kane M D, Breznak J A
Department of Microbiology, Michigan State University, East Lansing 48824-1101.
Arch Microbiol. 1991;156(2):91-8. doi: 10.1007/BF00290979.
A previously undescribed, H2-oxidizing CO2-reducing acetogenic bacterium was isolated from gut contents of the wood-feeding termite, Pterotermes occidentis. Cells of representative strain APO-1 were strictly anaerobic. Gram-negative, endospore-forming motile rods which measured 0.30-0.40 x 6-60 microm. Cells were catalase positive, oxidase negative, and had 51.5 mol percent G + C in their DNA. Optimum conditions for growth on H2 + CO2 were at 30-33 degrees C and pH (initial) 7.8, and under these conditions cells formed acetate according to the equation: 4 H2 + 2 CO2----CH3COOH + 2 H2O. Other energy sources supporting good growth of strain APO-1 included glucose, ribose, and various organic acids. Acetate and butyrate were major fermentation products from most organic compounds tested, however propionate, succinate, and 1,2-propanediol were also formed from some substrates. Based on comparative analysis of 16S rRNA nucleotide sequences, strain APO-1 was related, to but distinct from, members of the genus Sporomusa. Moreover, physiological and morphological differences between strain APO-1 and the six known species of Sporomusa were significant. Consequently, it is proposed herewith that a new genus, Acetonema, be established with strain APO-1 as the type strain of the new species, Acetonema longum. A. longum may contribute to the nutrition of P. occidentis by forming acetate, propionate and butyrate, compounds which are important carbon and energy sources for termites.
从食木白蚁西方翅白蚁（Pterotermes occidentis）的肠道内容物中分离出一种以前未被描述过的、氧化H2并还原CO2的产乙酸细菌。代表性菌株APO-1的细胞严格厌氧。革兰氏阴性、产芽孢的运动杆菌，大小为0.30 - 0.40×6 - 60微米。细胞过氧化氢酶阳性，氧化酶阴性，其DNA中G + C含量为51.5摩尔百分比。在H2 + CO2上生长的最佳条件是30 - 33℃和pH（初始）7.8，在这些条件下细胞根据以下方程式形成乙酸盐：4H2 + 2CO2→CH3COOH + 2H2O。支持菌株APO-1良好生长的其他能源包括葡萄糖、核糖和各种有机酸。乙酸盐和丁酸盐是大多数测试有机化合物的主要发酵产物，然而丙酸盐、琥珀酸盐和1,2 - 丙二醇也由一些底物形成。基于16S rRNA核苷酸序列的比较分析，菌株APO-1与芽孢梭菌属（Sporomusa）的成员相关，但又有所不同。此外，菌株APO-1与芽孢梭菌属的六个已知物种之间的生理和形态差异显著。因此，特此提议建立一个新属，丙酮线菌属（Acetonema），以菌株APO-1作为新物种长丙酮线菌（Acetonema longum）的模式菌株。长丙酮线菌可能通过形成乙酸盐、丙酸盐和丁酸盐来为西方翅白蚁提供营养，这些化合物是白蚁重要的碳源和能源。
