Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, Key Laboratory of Fermentation Engineering (Ministry of Education), College of Bioengineering, Hubei University of Technology, Wuhan 430068, PR China.
Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, Key Laboratory of Fermentation Engineering (Ministry of Education), College of Bioengineering, Hubei University of Technology, Wuhan 430068, PR China.
Bioresour Technol. 2014 Oct;169:559-565. doi: 10.1016/j.biortech.2014.06.056. Epub 2014 Jun 20.
In this study, a genetically engineered Escherichia coli strain, HBUT-D (ΔpflB Δpta ΔfrdABCD ΔadhE Δald ΔcscR), was initially evaluated on a laboratory scale (7 L) in a glucose (130 g L(-1)) mineral salts medium for d-lactic acid fermentation using 6N KOH, Ca(OH)2 or NH4OH as the neutralizing agent. Fermentations neutralized by Ca(OH) 2 achieved a volumetric productivity of 6.35 g L(-1) h(-1), tripling that achieved by KOH (1.71 g L(-1) h(-1)) and NH4OH (1.5 g L(-1) h(-1)). The facilitative effect of Ca(OH)2 neutralization was then demonstrated on a pilot scale (6 ton vessel, 130 kg glucose ton(-1)), resulting in a volumetric productivity of 6 kg ton(-1) h(-1), a titer of 126 kg ton(-1), a yield of 97%, and an optical purity of 99.5%. These results demonstrated that E. coli HBUT-D is a promising strain for large scale d-lactic acid fermentation using mineral salts medium and Ca(OH)2 for neutralization.
在这项研究中,我们首先在实验室规模(7 L)下,在含有 130 g/L 葡萄糖的无机盐培养基中,利用 6N KOH、Ca(OH)2 或 NH4OH 作为中和剂,对一株经过基因工程改造的大肠杆菌 HBUT-D(ΔpflB Δpta ΔfrdABCD ΔadhE Δald ΔcscR)进行了 d-乳酸发酵评估。用 Ca(OH)2 中和的发酵实现了 6.35 g/L/h 的比生产率,是 KOH(1.71 g/L/h)和 NH4OH(1.5 g/L/h)的三倍。然后,我们在中试规模(6 吨罐,130 kg 葡萄糖/吨)上验证了 Ca(OH)2 中和的促进作用,结果实现了 6 kg 吨(-1) h(-1)的比生产率、126 kg 吨(-1)的浓度、97%的产率和 99.5%的光学纯度。这些结果表明,大肠杆菌 HBUT-D 是一种很有前途的菌株,可用于使用无机盐培养基和 Ca(OH)2 进行中和的大规模 d-乳酸发酵。