Division of Environmental and Occupational Health Sciences, School of Public Health, University of California, Los Angeles, California 90024, and Ministéro da Indústria, Energia e Exportação, Departmento de Tecnologia de Indústrias Quimicas, Estrada das Paleiras, 2745 Queluz de Baixo, Portugal.
Appl Environ Microbiol. 1987 Jan;53(1):83-7. doi: 10.1128/aem.53.1.83-87.1987.
Methanosarcina barkeri 227 and Methanosarcina mazei S-6 grew with acetate as the substrate; we found little effect of H(2) on the rate of aceticlastic growth in the presence of various H(2) pressures between 2 and 810 Pa. We used physical (H(2) addition or flushing the headspace to remove H(2)) and biological (H(2)-producing or -utilizing bacteria in cocultures) methods for controlling H(2) pressure in Methanosarcina cultures growing on acetate. Added H(2) (ca. 100 Pa) was removed rapidly (a few hours) by M. barkeri and slowly (within a day) by M. mazei. When the H(2) produced by the aceticlastic methanogens was removed by coculturing with an H(2)-using Desulfovibrio sp., the H(2) pressure was about 2.2 Pa. Under these conditions the stoichiometry of aceticlastic methanogenesis did not change. H(2)-grown inocula of M. barkeri grew with acetate as the sole catabolic substrate if the inoculum culture was transferred during logarithmic growth to acetate-containing medium or if the transfer was accomplished within 1 or 2 days after exhaustion of H(2). H(2)-grown cultures incubated for 4 or more days after exhaustion of H(2) were able to grow with H(2) but not with acetate as the sole catabolic substrate. Addition of small quantities of H(2) to acetate-containing medium permitted these cultures to initiate growth on acetate.
巴氏甲烷八叠球菌 227 和沼泽甲烷八叠球菌 S-6 以乙酸盐作为底物生长；我们发现，在 2 至 810 Pa 之间的各种 H2 压力下，H2 对乙酸分解生长速率的影响很小。我们使用物理（添加 H2 或冲洗顶空以去除 H2）和生物（共培养中产生或利用 H2 的细菌）方法来控制以乙酸盐为底物生长的甲烷八叠球菌培养物中的 H2 压力。添加的 H2（约 100 Pa）被 M. barkeri 迅速（数小时内）去除，而被 M. mazei 缓慢（一天内）去除。当产乙酸甲烷菌产生的 H2 通过与利用 H2 的脱硫弧菌共培养去除时，H2 压力约为 2.2 Pa。在这些条件下，乙酸分解产甲烷的化学计量没有改变。如果将对数生长期的接种物培养液转移到含有乙酸盐的培养基中，或者在 H2 耗尽后 1 或 2 天内完成转移，则以 H2 生长的 M. barkeri 接种物可以以乙酸盐作为唯一的分解代谢底物生长。在 H2 耗尽后培养 4 天或更长时间的 H2 生长培养物能够以 H2 但不以乙酸盐作为唯一的分解代谢底物生长。向含有乙酸盐的培养基中添加少量 H2 可以使这些培养物开始在乙酸盐上生长。
