Stevens T O, Tiedje J M
Department of Microbiology and Public Health, Michigan State University, East Lansing 48824-1325.
Appl Environ Microbiol. 1988 Dec;54(12):2944-8. doi: 10.1128/aem.54.12.2944-2948.1988.
Fixation by strain DCB-1 of CO2 carbon into cell material and organic acids occurred during growth on pyruvate both with and without thiosulfate. By using sodium [14C]bicarbonate and sodium [2-14C]pyruvate, the isotopic composition of products and cells was investigated. Up to 70% of cell carbon was derived from CO2. CO2 carbon was also incorporated into succinate, formate, and acetate. Both carbons of acetate underwent exchange reactions with CO2, although the carboxyl-group exchange was twice as fast. Because strain DCB-1 uses CO2 as its major but not sole carbon source while deriving energy from pyruvate metabolism, we describe its metabolism as mixotrophic. Other mixotrophic conditions also supported growth. Lactate or butyrate, which could not support growth in mineral medium, could replace pyruvate as the oxidizable substrate only when acetate was added to the medium.
在以丙酮酸盐为生长底物且添加或不添加硫代硫酸盐的情况下，菌株DCB-1能将二氧化碳中的碳固定到细胞物质和有机酸中。通过使用[14C]碳酸氢钠和[2-14C]丙酮酸钠，对产物和细胞的同位素组成进行了研究。高达70%的细胞碳源自二氧化碳。二氧化碳中的碳也被整合到琥珀酸盐、甲酸盐和乙酸盐中。乙酸盐的两个碳都与二氧化碳发生了交换反应，不过羧基的交换速度是另一个碳的两倍。由于菌株DCB-1以二氧化碳作为主要而非唯一的碳源，同时从丙酮酸盐代谢中获取能量，因此我们将其代谢描述为兼养型。其他兼养条件也能支持其生长。在矿物培养基中不能支持生长的乳酸盐或丁酸盐，只有在向培养基中添加乙酸盐时，才能替代丙酮酸盐作为可氧化底物。
