Breedveld M W, Zevenhuizen L P, Zehnder A J
Department of Microbiology, Agricultural University, Wageningen, The Netherlands.
Appl Environ Microbiol. 1990 Jul;56(7):2080-6. doi: 10.1128/aem.56.7.2080-2086.1990.
At 25 degrees C, the optimal temperature for growth of Rhizobium trifolii TA-1, extracellular and capsular polysaccharide (EPS and CPS) were the main carbohydrate products synthesized in mannitol-rich medium (10 g of mannitol and 1 g of glutamic acid per liter). In the same medium at 33 degrees C, EPS and CPS production was inhibited, and up to 3.9 g of cyclic beta-(1,2)-glucan was produced during an incubation period of 20 days with a total biomass of 0.55 g of protein. In a medium containing 50 g of mannitol and 10 g of glutamic acid per liter, high cell densities (3.95 g of protein) were obtained at 25 degrees C. This biomass excreted 10.9 g of cyclic beta-(1,2)-glucan within 10 days. Concomitantly, 4.8 g of EPS were synthesized, while CPS production was strongly suppressed. The excreted cyclic beta-(1,2)-glucans were neutral and had degrees of polymerization ranging from 17 to 25, with a degree of polymerization of 19 as the major glucan cycle.
在25摄氏度（三叶草根瘤菌TA-1生长的最适温度）下，胞外多糖和荚膜多糖（EPS和CPS）是在富含甘露醇的培养基（每升含10克甘露醇和1克谷氨酸）中合成的主要碳水化合物产物。在相同培养基中于33摄氏度培养时，EPS和CPS的产生受到抑制，在20天的培养期内产生了高达3.9克的环状β-(1,2)-葡聚糖，总生物量为0.55克蛋白质。在每升含有50克甘露醇和10克谷氨酸的培养基中，于25摄氏度下可获得高细胞密度（3.95克蛋白质）。该生物量在10天内分泌了10.9克环状β-(1,2)-葡聚糖。同时，合成了4.8克EPS，而CPS的产生受到强烈抑制。分泌的环状β-(1,2)-葡聚糖呈中性，聚合度为17至25，其中聚合度为19的葡聚糖环为主。
