Department of Microbiology and Public Health, Michigan State University, East Lansing, Michigan 48824.
Appl Environ Microbiol. 1985 Mar;49(3):614-21. doi: 10.1128/aem.49.3.614-621.1985.
Putatively axenic cultures of Trichomitopsis termopsidis 6057, isolated by M. A. Yamin (J. Protozool. 25:535-538, 1978) from the hindgut of Zootermopsis termites, apparently contained methanogenic bacteria, inasmuch as small amounts of CH(4) were produced during growth. However, T. termopsidis could be "cured" of methanogenic activity by incubation in the presence of bromoethanesulfonate. Both the cured derivative (6057C) and the parent strain (6057) required NaHCO(3) and fetal bovine serum for good growth; the presence of yeast extract in media was stimulatory. Growth of both strains was markedly improved by substituting heat-killed cells of Bacteroides sp. strain JW20 (a termite gut isolate) for heat-killed rumen bacteria in media as a source of bacterial cell material. Heat-killed Bacteroides sp. strain JW20 was the best of a number of bacteria tested, and under these conditions H(2) was a major protozoan fermentation product. Growth of T. termopsidis strains was further improved by co-cultivation in the presence of Methanospirillum hungatii. M. hungatii was the best of a number of H(2)-consuming bacteria tested, and under these conditions CH(4), but not H(2), was produced, indicating interspecies transfer of H(2) between the protozoa and M. hungatii. Both strains of T. termopsidis used powdered, particulate forms of cellulose (e.g., pure cellulose, corncob, cereal leaves) as fermentable energy sources, although powdered wood, chitin, or xylan supported little or no growth. Cells of the cellulose-forming coccus Sarcina ventriculi also served as a fermentable energy source, but these were used poorly as a source of bacterial cell material. The only substantial difference between T. termopsidis 6057 and 6057C was that the latter grew poorly or not at all with rumen bacteria as a source of bacterial cell material. The improved growth of T. termopsidis in vitro should facilitate further studies on the cell biology and biochemistry of these symbiotic, anaerobic protozoa.
推测 Trichomitopsis termopsidis 6057 的无菌培养物是由 M. A. Yamin（J. Protozool. 25:535-538, 1978）从白蚁科白蚁的后肠中分离出来的，在生长过程中会产生少量的 CH(4)，这表明其中含有产甲烷细菌。然而，T. termopsidis 可以通过在溴乙磺酸钠存在下孵育来“消除”产甲烷活性。经驯化的衍生物（6057C）和原始菌株（6057）都需要 NaHCO(3)和胎牛血清才能良好生长；培养基中添加酵母提取物具有刺激作用。用热灭活的拟杆菌 JW20 细胞（一种白蚁肠道分离株）代替培养基中的热灭活瘤胃细菌作为细菌细胞物质的来源，可显著改善两种菌株的生长。经过热灭活的拟杆菌 JW20 是经过测试的多种细菌中最好的一种，在这些条件下，H(2)是主要的原生动物发酵产物。在 Methanospirillum hungatii 的存在下共培养可进一步提高 T. termopsidis 菌株的生长。M. hungatii 是经过测试的多种 H(2)消耗细菌中最好的一种，在这些条件下，产生了 CH(4)，但没有 H(2)，这表明原生动物和 M. hungatii 之间发生了 H(2)的种间转移。两种 T. termopsidis 菌株都使用粉状、颗粒状纤维素（如纯纤维素、玉米芯、谷物叶片）作为可发酵能源，尽管粉状木材、几丁质或木聚糖支持的生长很少或没有。产甲烷球菌 Sarcina ventriculi 的细胞也可用作可发酵能源，但作为细菌细胞物质的来源使用效果不佳。T. termopsidis 6057 和 6057C 之间唯一的实质性差异是后者在以瘤胃细菌作为细菌细胞物质来源时生长不良或根本不生长。T. termopsidis 在体外的生长得到改善，这将有助于进一步研究这些共生、厌氧原生动物的细胞生物学和生物化学。
