Tangney M, Rousse C, Yazdanian M, Mitchell W J
Department of Biological Sciences, Heriot-Watt University, Edinburgh, UK.
J Appl Microbiol. 1998 May;84(5):914-9. doi: 10.1046/j.1365-2672.1998.00432.x.
Sucrose is the major carbon source in molasses, the traditional substrate employed in the industrial acetonebutanol-ethanol (ABE) fermentation by solventogenic clostridia. The utilization of sucrose by Clostridium beijerinckii NCIMB 8052 was investigated. Extracts prepared from cultures grown on sucrose (but not xylose or fructose) as the sole carbon source possessed sucrose phosphoenolpyruvate (PEP)-dependent phosphotransferase system (PTS) activity. Extract fractionation and reconstitution experiments revealed that the entire sucrose Enzyme II complex resides within the membrane in this organism. Sucrose-6-phosphate hydrolase and fructokinase activities were also detected in sucrose grown cultures. The fructokinase activity, which is required specifically during growth on sucrose, was shown to be inducible under these conditions. A pathway for sucrose metabolism in this organism is proposed.
蔗糖是糖蜜中的主要碳源，糖蜜是产溶剂梭菌进行工业丙酮-丁醇-乙醇（ABE）发酵所采用的传统底物。对拜氏梭菌NCIMB 8052利用蔗糖的情况进行了研究。以蔗糖（而非木糖或果糖）作为唯一碳源培养得到的提取物具有蔗糖磷酸烯醇丙酮酸（PEP）依赖性磷酸转移酶系统（PTS）活性。提取物分级分离和重组实验表明，该生物体中整个蔗糖酶II复合物位于膜内。在以蔗糖培养的菌体中还检测到了蔗糖-6-磷酸水解酶和果糖激酶活性。果糖激酶活性在以蔗糖生长过程中是特异性必需的，在这些条件下显示为可诱导的。本文提出了该生物体中蔗糖代谢的一条途径。
