Residual phosphate concentration under nitrogen-limiting conditions regulates curdlan production in Agrobacterium species
Residual phosphate concentration under nitrogen-limiting conditions regulates curdlan production in Agrobacterium species
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DOI：
10.1038/sj.jim.7000053
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发表时间：
2000-10-01
影响因子：
3.4
通讯作者：
Park, YH
中科院分区：
文献类型：
--
作者：
Kim, MK;Lee, IY;Park, YH
研究了无机磷浓度对农杆菌产可德聚糖的影响。采用两步培养法，首先培养细胞，然后在限制氮气的条件下生产柯德兰。在可得聚糖的生产步骤中，细胞不生长，而是将糖代谢成可得聚糖。摇瓶试验表明，发酵生产柯德兰的最适磷酸盐浓度为0.1~0.3g L。摇瓶发酵中，随着细胞浓度从0.42g L(-1)增加到1.68g，可德聚糖产量从0.44g L(-1)增加到2.80g L(-1)。然而，最适磷酸盐浓度范围并不依赖于细胞浓度。无论菌体浓度如何，比转化率均为70 mg·g-cell(-1)·h~(-1)，当磷浓度维持在0.5g·L(-1)时，120h可获得65g·L(-1)的可得性。
We investigated the influence of inorganic phosphate concentration on the production of curdlan by Agrobacterium species. A two-step culture method was employed where cells were first cultured, followed by curdlan production under nitrogen-limiting conditions. In the curdlan production step, cells did not grow but metabolized sugar into curdlan. Shake-flask experiments showed that the optimal phosphate concentration for curdlan production was in the range of 0.1-0.3 g l(-1). As the cell concentration increased from 0.42 to 1.68 g l(-1) in shake-flask cultures, curdlan production increased from 0.44 to 2.80 g l(-1). However, the optimal phosphate concentration range was not dependent upon cell concentration. The specific production rate was about 70 mg curdlan g-cell(-1) h(-1) irrespective of cell concentration, When the phosphate concentration was maintained at 0.5 g l(-1) under nitrogen-limiting conditions, as high as 65 g l(-1) of curdlan was obtained in 120 h.