Enhanced Reducing Equivalent Generation for 1,3-Propanediol Production Through Cofermentation of Glycerol and Xylose by Klebsiella pneumoniae

Jin, Peng; Lu, Shiping; Huang, He; Luo, Fang; Li, Shuang

doi:10.1007/s12010-011-9373-1

Cited by 15 publications

(5 citation statements)

References 22 publications

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“…Many strategies based on adjusting the intracellular redox level to enhance bioproduct formation in K. pneumoniae have been reported . In the present study, inactivating NQOs either inhibited cell growth or increased the cellular NADH:NAD + ratio, depending on the NQOs inactivated.…”

Section: Discussionmentioning

confidence: 60%

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Inactivating NADH:quinone oxidoreductases affects the growth and metabolism of Klebsiella pneumoniae

Zhang

Bao

Wei

et al. 2018

Biotech and App Biochem

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NADH:quinone oxidoreductases (NQOs) act as the electron entry sites in bacterial respiration and oxidize intracellular NADH that is essential for the synthesis of numerous molecules. Klebsiella pneumoniae contains three NQOs (NDH-1, NDH-2, and NQR). The effects of inactivating these NQOs, separately and together, on cell metabolism were investigated under different culture conditions. Defective growth was evident in NDH-1-NDH-2 double and NDH-1-NDH-2-NQR triple deficient mutants, which was probably due to damage to the respiratory chain. The results also showed that K. pneumoniae can flexibly use NQOs to maintain normal growth in single NQO-deficient mutants. And more interestingly, under aerobic conditions, inactivating NDH-1 resulted in a high intracellular NADH:NAD ratio, which was proven to be beneficial for 2,3-butanediol production. Compared with the parent strain, 2,3-butanediol production by the NDH-1-deficient mutant was increased by 46% and 62% in glycerol- and glucose-based media, respectively. Thus, our findings provide a practical strategy for metabolic engineering of respiratory chains to promote the biosynthesis of 2,3-butanediol in K. pneumoniae.

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Section: Discussionmentioning

confidence: 60%

“…inactivated the ldhA gene, which is responsible for lactate formation, resulting in a slight increase in 1,3‐PD and substantial improvement in the production of 2,3‐BD . In addition, the amount of reducing equivalents in cells was increased by co‐fermentation of glycerol and xylose, resulting in an increase in 1,3‐PD formation .…”

Section: Introductionmentioning

confidence: 99%

Inactivating NADH:quinone oxidoreductases affects the growth and metabolism of Klebsiella pneumoniae

Zhang

Bao

Wei

et al. 2018

Biotech and App Biochem

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“…There are many successful examples in the literature reporting cosubstrate fermentation to achieve better fermentation performance and to increase product yields. Adding sugars, mannitol, or hemicellulose hydrolysate as a cosubstrate to glycerol can significantly increase the yield of 1,3-propanediol production (31)(32)(33). Beet molasses added as a cosubstrate promoted 2,3-butanediol production from biodiesel derived glycerol (34).…”

Section: Discussionmentioning

confidence: 99%

Homoethanol Production from Glycerol and Gluconate Using Recombinant Klebsiella oxytoca Strains

Tao

Wang

Walters

et al. 2019

Appl Environ Microbiol

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Gluconic acid, an oxidized cellulose degradation product, could be produced from cellulosic biomass. Glycerol is an inexpensive and renewable resource for fuels and chemicals production and is available as a byproduct of biodiesel production. Gluconate is a more oxidized substrate than glucose, whereas glycerol is a more reduced substrate than glucose. Although the production of homoethanol from glucose can be achieved, the conversion of gluconate to ethanol is accompanied by the production of oxidized byproduct such as acetate, and reduced byproducts such as 1,3-propanediol are produced, along with ethanol, when glycerol is used as the carbon source. When gluconate and glycerol are used as the sole carbon source by Klebsiella oxytoca BW21, the ethanol yield is about 62 to 64%. Coutilization of both gluconate and glycerol in batch fermentation increased the yield of ethanol to about 78.7% and decreased by-product accumulation (such as acetate and 1,3-propanediol) substantially. Decreasing by-product formation by deleting the pta, frd, ldh, pflA, and pduC genes in strain BW21 increased the ethanol yield to 89.3% in the batch fermentation of a glycerol-gluconate mixture. These deletions produced the strain K. oxytoca WT26. However, the utilization rate of glycerol was significantly slower than that of gluconate in batch fermentation. In addition, substantial amounts of glycerol remain unutilized after gluconate was depleted in batch fermentation. Continuous fed-batch fermentation was used to solve the utilization rate mismatch problem for gluconate and glycerol. An ethanol yield of 97.2% was achieved in continuous fed-batch fermentation of these two substrates, and glycerol was completely used at the end of the fermentation. IMPORTANCE Gluconate is a biomass-derived degradation product, and glycerol can be obtained as a biodiesel byproduct. Compared to glucose, using them as the sole substrate is accompanied by the production of by-products. Our study shows that through pathway engineering and adoption of a fed-batch culture system, high-yield homoethanol production that usually can be achieved by using glucose as the substrate is achievable using gluconate and glycerol as cosubstrates. The same strategy is expected to be able to achieve homofermentative production of other products, such as lactate and 2,3-butanediol, which can be typically achieved using glucose as the substrate and inexpensive biodiesel-derived glycerol and biomass-derived gluconate as the cosubstrates.

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“…Xylose is another abundant monosaccharide after glucose. It has been reported that xylose could be used as a cosubstrate to increase the production of 1,3-PD in K. pneumoniae from glycerol [8]. In Klebsiella, xylose is converted into xylulose by xylose isomerase (XylA) and then catalyzed into xylulose 5-phosphate by xylulokinase (XylB).…”

Section: Introductionmentioning

confidence: 99%

Overexpressions of xylA and xylB in Klebsiella pneumoniae Lead to Enhanced 1,3-Propanediol Production by Cofermentation of Glycerol and Xylose

Zong

et al. 2016

Journal of Microbiology and Biotechnology

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1,3-Propanediol (1,3-PD) is a valuable platform compound. Many studies have shown that the supplement of NADH plays a key role in the bioproduction of 1,3-PD from Klebsiella pneumoniae. In this study, the xylA and xylB genes from Escherichia coli were overexpressed individually or simultaneously in K. pneumoniae to improve the production of 1,3-PD by cofermentation of glycerol and xylose. Compared with the parent strain, the xylose consumption was significantly increased by the introduction of these two genes. The 1,3-PD titers were raised from 17.9 g/l to 23.5, 23.9, and 24.4 g/l, respectively, by the overexpression of xylA and xylB as well as their coexpression. The glycerol conversion rate (mol/mol) was enhanced from 54.1% to 73.8%. The concentration of 2,3-butanediol was increased by 50% at the middle stage but drastically decreased after that. The NADH and NADH/NAD(+) ratio were improved. This report suggests that overexpression of xylA or xylB is an effective strategy to improve the xylose assimilation rate to provide abundant reducing power for the biosynthesis of 1,3-PD in K. pneumoniae.

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Enhanced Reducing Equivalent Generation for 1,3-Propanediol Production Through Cofermentation of Glycerol and Xylose by Klebsiella pneumoniae

Cited by 15 publications

References 22 publications

Inactivating NADH:quinone oxidoreductases affects the growth and metabolism of Klebsiella pneumoniae

Inactivating NADH:quinone oxidoreductases affects the growth and metabolism of Klebsiella pneumoniae

Homoethanol Production from Glycerol and Gluconate Using Recombinant Klebsiella oxytoca Strains

Overexpressions of xylA and xylB in Klebsiella pneumoniae Lead to Enhanced 1,3-Propanediol Production by Cofermentation of Glycerol and Xylose

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