Production of L-lactic acid by a thermophilic Bacillus mutant using sodium hydroxide as neutralizing agent
Production of L-lactic acid by a thermophilic Bacillus mutant using sodium hydroxide as neutralizing agent
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DOI：
10.1016/j.biortech.2010.04.037
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发表时间：
2010-10-01
影响因子：
11.4
通讯作者：
Xu, Ping
中科院分区：
文献类型：
--
作者：
Qin, Jiayang;Wang, Xiuwen;Xu, Ping
筛选得到一株耐乳酸钠的突变菌株，命名为Bacillus sp. Na-2，并将其应用于氢氧化钠基乳酸菌发酵。乳酸（LA）生产工艺。为进一步提高菌株Na-2对乳酸钠胁迫的抵抗能力，获得最佳的L-乳酸生产工艺，研究了通气量和pH值对L-乳酸生产的影响。虽然温和的通风有利于细胞生长和L-LA生产，但剧烈通风导致从纯乳酸发酵到混合酸/乙偶姻发酵的代谢转变。因此，采用了两级曝气控制策略。最适pH为6.0。以氢氧化钠为中和剂，芽孢杆菌Na-2在30 h内产L-乳酸106.0 g/l。产率、转化率和光学纯度分别为3.53 g/l/h、94%和99.5%。Bacillus sp. Na-2的优良发酵特性和NaOH工艺的环境友好性为工业化生产L-LA提供了新的思路。(C)2010爱思唯尔有限公司保留所有权利。
A sodium lactate tolerant mutant strain named Bacillus sp. Na-2 was obtained and applied to sodium hydroxide-based L.-lactic acid (LA) production process. The influences of aeration and pH were investigated to further improve the resistance of strain Na-2 against sodium lactate stress and to obtain the most efficient L-LA production process. Although mild aeration was favorable for cell growth and L-LA production, vigorous aeration resulted in a metabolic shift from homolactic to mixed-acid/acetoin fermentation. Therefore, a two-stage aeration control strategy was employed. Optimum pH was found to be 6.0. A total of 106.0 g/l L-LA was produced in 30 h by Bacillus sp. Na-2 using sodium hydroxide as neutralizing agent. Productivity, conversion rate and optical purity were 3.53 g/l/h, 94% and 99.5%, respectively. The remarkable fermentation traits of Bacillus sp. Na-2 and the environment-friendly characteristics of NaOH-based process represent new insight for industrial scale production of L-LA. (C) 2010 Elsevier Ltd. All rights reserved.