Improved H+/O ratio and cell yield of Escherichia coli with genetically altered terminal quinol oxidases

Minohara, Shinji; Sakamoto, Junshi; Sone, Nobuhito

doi:10.1016/s1389-1723(02)80093-7

Cited by 10 publications

(7 citation statements)

References 27 publications

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“…It was concluded that the PPO electron flow towards oxygen remains largely intact as long as one out of the two cytochrome oxidases is present in the cell. Partial cross complementation of cyo and cyd mutants was observed before (25,26). The clear cut HemG deficiency in the cyo/cyd double mutant revealed exclusive coupling of HemG to these two systems under aerobic growth conditions.…”

Section: Resultsmentioning

confidence: 96%

Heme biosynthesis is coupled to electron transport chains for energy generation

Möbius¹,

Arias-Cartin

Breckau³

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

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Cellular energy generation uses membrane-localized electron transfer chains for ATP synthesis. Formed ATP in turn is consumed for the biosynthesis of cellular building blocks. In contrast, heme cofactor biosynthesis was found driving ATP generation via electron transport after initial ATP consumption. The FMN enzyme protoporphyrinogen IX oxidase (HemG) of Escherichia coli abstracts six electrons from its substrate and transfers them via ubiquinone, cytochrome bo 3 (Cyo) and cytochrome bd (Cyd) oxidase to oxygen. Under anaerobic conditions electrons are transferred via menaquinone, fumarate (Frd) and nitrate reductase (Nar). Cyo, Cyd and Nar contribute to the proton motive force that drives ATP formation. Four electron transport chains from HemG via diverse quinones to Cyo, Cyd, Nar, and Frd were reconstituted in vitro from purified components. Characterization of E. coli mutants deficient in nar, frd, cyo, cyd provided in vivo evidence for a detailed model of heme biosynthesis coupled energy generation.anabolism coupled catabolism | protoporphyrinogen IX oxidase | HemG | tetrapyrrole | respiration

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Section: Resultsmentioning

confidence: 96%

Heme biosynthesis is coupled to electron transport chains for energy generation

Möbius¹,

Arias-Cartin

Breckau³

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

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“…7). An increased cell yield was also observed for an E. coli mutant deficient in the bo 3 and the bd-I oxidase when the bo 3 oxidase gene was overexpressed by a plasmid (20). The possibility that an increased level of bo 3 oxidase in G. oxydans causes a shift of the electron flux from the non-protonpumping bd oxidase to the proton-pumping bo 3 oxidase appears unlikely as the G. oxydans cyd deletion mutant did not show improved growth although only the bo 3 oxidase remained as a terminal oxidase.…”

Section: Discussionmentioning

confidence: 80%

“…In the literature, H ϩ /O ratios reported for E. coli vary between 3.4 and 4.9 (20,34,40). A major difference between the respiratory chains of the two species is the lack of the multisubunit proton-pumping NADH dehydrogenase I (NDH-I) in G. oxydans.…”

Section: Discussionmentioning

confidence: 99%

“…In comparison to these values, E. coli reaches a value of 0.49 g cdw /g of glucose, and Bacillus subtilis reaches a yield of 0.32 g cdw /g of glucose (18,19). It has been shown for several respiring bacteria that the cell yield correlates with the H ϩ /O ratio measured by the oxygen pulse method (20,21). Acetobacter pasteurianus for example has a H ϩ /O ratio of 1.9 Ϯ 0.1 and a cell yield of 13.1 g cdw /mol of ethanol, whereas Paracoccus pantotrophus shows a H ϩ /O ratio of 4.9 Ϯ 0.3 and reaches a cell yield of 25.2 g cdw /mol of ethanol (21).…”

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confidence: 99%

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Evidence for a Key Role of Cytochrome bo3 Oxidase in Respiratory Energy Metabolism of Gluconobacter oxydans

Richhardt

Luchterhand

Bringer

et al. 2013

Journal of Bacteriology

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The obligatory aerobic acetic acid bacterium Gluconobacter oxydans oxidizes a variety of substrates in the periplasm by membrane-bound dehydrogenases, which transfer the reducing equivalents to ubiquinone. Two quinol oxidases, cytochrome bo 3 and cytochrome bd, then catalyze transfer of the electrons from ubiquinol to molecular oxygen. In this study, mutants lacking either of these terminal oxidases were characterized. Deletion of the cydAB genes for cytochrome bd had no obvious influence on growth, whereas the lack of the cyoBACD genes for cytochrome bo 3 severely reduced the growth rate and the cell yield. Using a respiration activity monitoring system and adjusting different levels of oxygen availability, hints of a low-oxygen affinity of cytochrome bd oxidase were obtained, which were supported by measurements of oxygen consumption in a respirometer. The H ؉ /O ratio of the ⌬cyoBACD mutant with mannitol as the substrate was 0.56 ؎ 0.11 and more than 50% lower than that of the reference strain (1.26 ؎ 0.06) and the ⌬cydAB mutant (1.31 ؎ 0.16), indicating that cytochrome bo 3 oxidase is the main component for proton extrusion via the respiratory chain. Plasmid-based overexpression of cyoBACD led to increased growth rates and growth yields, both in the wild type and the ⌬cyoBACD mutant, suggesting that cytochrome bo 3 might be a rate-limiting factor of the respiratory chain.

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“…The H + /O ratio for the reference strain, G. oxydans ZJU3, was measured as 1.21 ± 0.11. In the literature, H + /O ratios reported for E. coli vary between 3.4 and 4.5 [ 36 , 37 ], which was more than 2-fold higher than that of the G. oxydans ZJU3 strain. A major difference of the respiratory chain between the two species is the lack of the multisubunit proton-pumping NADH dehydrogenase I (NDH-I) in the G. oxydans [ 10 , 25 ].…”

Section: Resultsmentioning

confidence: 99%

Combinatorial metabolic engineering of industrial Gluconobacter oxydans DSM2343 for boosting 5-keto-D-gluconic acid accumulation

Yuan

Lin

et al. 2016

BMC Biotechnol

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BackgroundL-(+)-tartaric acid (L-TA) is an important organic acid, which is produced from the cream of tartar or stereospecific hydrolysis of the cis-epoxysuccinate. The former method is limited by the availability of raw material and the latter is dependent on the petrochemical material. Thus, new processes for the economical preparation of L-TA from carbohydrate or renewable resource would be much more attractive. Production of 5-keto-D-gluconate (5-KGA) from glucose by Gluconobacter oxydans is the first step to produce L-TA. The aim of this work is to enhance 5-KGA accumulation using combinatorial metabolic engineering strategies in G. oxydans. The sldAB gene, encoding sorbitol dehydrogenase, was overexpressed in an industrial strain G. oxydans ZJU2 under a carefully selected promoter, P0169. To enhance the efficiency of the oxidation by sldAB, the coenzyme pyrroloquinoline quinone (PQQ) and respiratory chain were engineered. Besides, the role in sldAB overexpression, coenzyme and respiratory chain engineering and their subsequent effects on 5-KGA production were investigated.ResultsAn efficient, stable recombinant strain was constructed, whereas the 5-KGA production could be enhanced. By self-overexpressing the sldAB gene in G. oxydans ZJU2 under the constitutive promoter P0169, the resulting strain, G. oxydans ZJU3, produced 122.48 ± 0.41 g/L of 5-KGA. Furthermore, through the coenzyme and respiratory chain engineering, the titer and productivity of 5-KGA reached 144.52 ± 2.94 g/L and 2.26 g/(L · h), respectively, in a 15 L fermenter. It could be further improved the 5-KGA titer by 12.10 % through the fed-batch fermentation under the pH shift and dissolved oxygen tension (DOT) control condition, obtained 162 ± 2.12 g/L with the productivity of 2.53 g/(L · h) within 64 h.ConclusionsThe 5-KGA production could be significantly enhanced with the combinatorial metabolic engineering strategy in Gluconobacter strain, including sldAB overexpression, coenzyme and respiratory chain engineering. Fed-batch fermentation could further enlarge the positive effect and increase the 5-KGA production. All of these demonstrated that the robust recombinant strain can efficiently produce 5-KGA in larger scale to fulfill the industrial production of L-TA from 5-KGA.

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Improved H+/O ratio and cell yield of Escherichia coli with genetically altered terminal quinol oxidases

Cited by 10 publications

References 27 publications

Heme biosynthesis is coupled to electron transport chains for energy generation

Heme biosynthesis is coupled to electron transport chains for energy generation

Evidence for a Key Role of Cytochrome bo3 Oxidase in Respiratory Energy Metabolism of Gluconobacter oxydans

Combinatorial metabolic engineering of industrial Gluconobacter oxydans DSM2343 for boosting 5-keto-D-gluconic acid accumulation

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