State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Dongying 257061, PR China.
Bioresour Technol. 2011 Oct;102(19):9175-8. doi: 10.1016/j.biortech.2011.06.086. Epub 2011 Jul 2.
The effect of pH-control modes on cell growth and exopolysaccharide production by Tremella fuciformis was evaluated in a 5-L bioreactor. The results show that the maximal dry cell weight (DCW) and exopolysaccharide production were 23.57 and 4.48 g L⁻¹ in pH-stat fermentation, where the maximal specific growth rate (μ(max)) and specific production rate of exopolysaccharide (P(P/X)) were 1.03 and 0.24 d⁻¹, respectively; under pH-shift cultivation, the maximal DCW and exopolysaccharide production were 30.57 and 3.90 g L⁻¹, where the μ(max) and P(P/X) were 1.21 and 0.06 d⁻¹. Unlike batch fermentation, maximal DCW and exopolysaccharide production merely reached 15.04 and 2.0 g L⁻¹, where the μ(max) and P(P/X) were 0.86 and 0.05 d⁻¹, respectively. These results suggest that a pH-stat strategy is a more efficient way of performing the fermentation process to increase exopolysaccharide production. Furthermore, this research has also proved that the three-stage pH-control mode is effective for cell growth.
在 5L 生物反应器中评价了 pH 控制模式对银耳细胞生长和胞外多糖生产的影响。结果表明，在 pH -stat 发酵中，最大干细胞重量（DCW）和胞外多糖产量分别为 23.57 和 4.48g/L，最大比生长速率（μ(max)）和胞外多糖比生产速率（P(P/X)）分别为 1.03 和 0.24d⁻¹；在 pH 切换培养下，最大 DCW 和胞外多糖产量分别为 30.57 和 3.90g/L，μ(max)和 P(P/X)分别为 1.21 和 0.06d⁻¹。与分批发酵不同，最大 DCW 和胞外多糖产量仅分别达到 15.04 和 2.0g/L，μ(max)和 P(P/X)分别为 0.86 和 0.05d⁻¹。这些结果表明，pH-stat 策略是一种更有效的发酵方法，可以提高胞外多糖的产量。此外，本研究还证明了三段式 pH 控制模式对细胞生长有效。
