Acetate and ethanol production from H2 and CO2 by Moorella sp using a repeated batch culture
Acetate and ethanol production from H2 and CO2 by Moorella sp using a repeated batch culture
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DOI：
10.1263/jbb.99.252
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发表时间：
2005-03-01
影响因子：
2.8
通讯作者：
Nishio, N
中科院分区：
文献类型：
--
作者：
Sakai, S;Nakashimada, Y;Nishio, N
采用非竞争性抑制模型结合pH抑制模型分析了未解离乙酸对穆尔氏菌HUC 22 -1生长的抑制作用。在H-2和CO2上生长的细胞中，未解离的乙酸的抑制常数K-P为6.2 mM（在pH 6.2，pKa=4.795，55 ℃时，以总乙酸计为164 mM），这比在果糖上生长的细胞中获得的抑制常数K-P高1.5倍。当使用发酵罐在pH 6.2下用H-2和CO2进行pH控制的分批培养时，在220 h后产生最大0.92 g/l的干细胞重量和339 mM的乙酸盐，其分别是在pH控制的分批培养中产生的那些的4.4倍和6.8倍。为了减少培养基中的乙酸盐抑制，在恒定pH下用H2和CO2进行具有细胞再循环的重复分批培养。在pH为6.2的条件下，发酵420 h后，乙酸的总产量达到840 mmol/L反应器，乙醇的总产量为4.7 mmol/L反应器。当pH值保持在5.8时，乙醇的总产量在430 h后达到15.4 mmol/L反应器，但乙酸的总产量下降到675 mmol/L反应器。
The growth inhibition of Moorella sp. HUC22-1 by undissociated acetic acid was analyzed using a non-competitive inhibition model coupled with a pH inhibition model. In the cells grown on H-2 and CO2, the inhibition constant, K-P of the undissociated acetic acid was 6.2 mM (164 mM as the total acetate at pH 6.2, pKa=4.795, 55 degrees C), which was 1.5-fold higher than that obtained in cells grown on fructose. When a pH-controlled batch culture was performed using a fermentor at pH 6.2 with H-2 and CO2, a maximum of 0.92 g/l of dry cell weight and 339 mM of acetate were produced after 220 h, which were 4.4- and 6.8-fold higher than those produced in the pH-uncontrolled batch culture, respectively. In order to reduce acetate inhibition in the culture medium, a repeated batch culture with cell recycling was performed at a constant pH with H2 and CO2. At a pH of 6.2, the total acetate production reached 840 mmol/l-reactor with 4.7 mmol//-reactor of total ethanol production after 420 h. When the culture pH was maintained at 5.8, which was the optimum for ethanol production, the total ethanol production reached 15.4 mmol/l-reactor after 430 h, although the total acetate production was decreased to 675 mmol/l-reactor.