Role of pH-regulation in lactic acid fermentation: Second steps in a process improvement
Role of pH-regulation in lactic acid fermentation: Second steps in a process improvement
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DOI：
10.1016/j.cep.2011.01.008
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发表时间：
2011-03-01
影响因子：
4.3
通讯作者：
Sevella, Bela
中科院分区：
文献类型：
--
作者：
Hetenyi, Kata;Nemeth, Aron;Sevella, Bela
乳酸在化学工业中具有广泛的应用，它可以从生物质资源中经济地生产，例如从含有高浓度易发酵糖（150-180 gL(-1)）的甜高粱汁中生产。为了中和产生的乳酸，添加碱（即滴定）或pH缓冲以避免未离解的乳酸的抑制作用。然而，如此高浓度的离子化乳酸也会抑制生长和进一步生产。我们的任务是找到合适的 pH 调节方法并描述所用菌株的 pH 依赖性。测试了五种pH调节剂，其中三甲胺的生产率结果最好（3.13 gL(-1) h(-1)），但考虑到技术方面（如稀释），也推荐使用氢氧化铵。比较了NH4OH滴定法和CaCO3缓冲法，然后将其结合起来，得到了非常好的生产率(3.55 gL(-1) h(-1))。还检查了所用菌株的 pH 依赖性，最佳 pH 值在 6.8 至 7.0 之间。 (C) 2011 Elsevier B.V. 保留所有权利。
Lactic acid has versatile application in chemical industries and it can be economically produced from biomass resources, for example from sweet sorghum juice, containing easily fermentable sugars in high concentration (150-180 gL(-1)). To neutralize the produced lactic acid, alkali addition (i.e., titration) or pH buffering was applied to avoid the inhibitory effect of the undissociated lactic acid. However, such a high concentration of ionized lactate also inhibits the growth and further production. Our task was to find an appropriate pH regulation method and to describe pH dependency of the used strain. Five pH regulation agents were tested and among them trimethylamine gave the best productivity result (3.13 gL(-1) h(-1)), but considering technological aspects (such as dilution) ammonium hydroxide is also recommended. Titration by NH4OH and buffering by CaCO3 were compared, and then combined, resulted in very good productivity (3.55 gL(-1) h(-1)). pH dependence of the used strain was also examined and the optimal pH value was between 6.8 and 7.0. (C) 2011 Elsevier B.V. All rights reserved.