Aldehyde dehydrogenase activity is important to the production of 3-hydroxypropionic acid from glycerol by recombinant Klebsiella pneumoniae
Aldehyde dehydrogenase activity is important to the production of 3-hydroxypropionic acid from glycerol by recombinant Klebsiella pneumoniae
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DOI：
10.1016/j.procbio.2012.04.007
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发表时间：
2012-07-01
影响因子：
4.4
通讯作者：
Park, Sunghoon
中科院分区：
文献类型：
--
作者：
Ko, Yeounjoo;Ashok, Somasundar;Park, Sunghoon
3-在肺炎克雷伯氏菌（Klebsiella pneumoniae）中，甘油经辅酶B-12依赖性甘油脱氢酶（GDHt）和乙醛脱氢酶（ALDH）催化的两个酶促反应可合成3-羟基丙酸（3-HP）。细胞内GDHt活性随K.肺炎链球菌的产3-HP能力较高，3-HP的总产率受ALDH活性控制。为了研究不同的ALDH活性对3-HP生产的影响，三种不同的ALDH，来自大肠杆菌的AldH（EaldH）。PuuC从K. pneumoniae（PuuC）和巴西固氮菌KGSADH（KGSADH）在不同的重组克雷伯氏菌中进行了表达和比较。pneumoniae菌株此外，从K. pneurnoniae，以提高从3-HPA到3-HP的碳通量。在不同的重组K. pneumoniae中，KGSADH表现出最高的粗细胞活性（8.0U/mg蛋白），分别是PuuC和EaldH的2倍和4倍。在含100 mM甘油和K.在九种重组菌株（三种ALDH X三种宿主菌株;一种野生型和两种突变体）中，肺炎Δ dhaT（KGSADH）导致最高滴度（64 mM）。在甘油补料分批生物反应器培养中。K. pneumoniae Delta dhaT（KGSADH）在48小时内表现出>16 g/L的3-HP产量，甘油碳产率> 40%。相比之下，K。pneumoniae Delta dhaT（PuuC）在48 h内仅产生11 g/L的3-HP，产率> 23%。本研究表明，高的ALDH活性对于用重组K.肺炎。(c)2012爱思唯尔有限公司保留所有权利。
3-Hydroxypropionic acid (3-HP) can be produced from glycerol via two enzymatic reactions catalyzed by a coenzyme B-12-dependent glycerol dehydratase (GDHt) and aldehyde dehydrogenase (ALDH) in Klebsiella pneumoniae. As the intracellular GDHt activity in K. pneumoniae is high, the overall rate of 3-HP production is controlled by the ALDH activity. To examine the effect of different ALDH activity on 3-HP production, three different ALDHs, AldH from Escherichia coli (EaldH). PuuC from K. pneumoniae (PuuC) and KGSADH from Azospirillum brasilense (KGSADH), were overexpressed and compared in various recombinant K. pneumoniae strains. In addition, the genes encoding DhaT and YqhD, which are responsible for the conversion of 3-hydroxypropionaldehyde (3-HPA) to 1,3-propanediol (1,3-PDO), were disrupted individually from K. pneurnoniae to enhance the carbon flux from 3-HPA to 3-HP. When the ALDH activity was measured in various recombinant K. pneumoniae, KGSADH showed the highest crude cell activity of 8.0 U/mg protein, which was 2 and 4 times higher than that of PuuC and EaldH, respectively. The different ALDH activities had a significant effect on 3-HP production in a flask culture containing 100 mM glycerol, and K. pneumoniae Delta dhaT(KGSADH) resulted in the highest titer (64 mM) among the nine recombinant strains (three ALDH x three host strains; one wild type and two mutants). In glycerol fed-batch bioreactor cultivation. K. pneumoniae Delta dhaT (KGSADH) exhibited 3-HP production at >16 g/L in 48h with a glycerol carbon yield of >40%. In comparison, K. pneumoniae Delta dhaT (PuuC) produced only 11 g/L 3-HP in 48 h with a yield of >23%. This study demonstrates that a high ALDH activity is essential for the effective production of 3-HP from glycerol with recombinant K. pneumoniae. (c) 2012 Elsevier Ltd. All rights reserved.