Vitreoscilla Haemoglobin: A Tool to Reduce Overflow Metabolism

Taymaz-Nikerel, Hilal; Lara, Alvaro R.

doi:10.3390/microorganisms10010043

Cited by 9 publications

(10 citation statements)

References 88 publications

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“…Aerobic respiration occurs with the appropriate amounts of dissolved oxygen, allowing B. tequilensis BL01 to produce more energy, accelerating growth and γ-PGA synthesis. It is not feasible to maintain high dissolved oxygen by fermentation alone; future research will employ metabolic engineering strategies to improve dissolved oxygen, such as the expression of Vitreoscilla hemoglobin ( VHb ) in B. tequilensis BL01 [ 50 ].…”

Section: Resultsmentioning

confidence: 99%

Engineering of a newly isolated Bacillus tequilensis BL01 for poly-γ-glutamic acid production from citric acid

Wang

Zhou

et al. 2022

Microb Cell Fact

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Background Poly γ-glutamic acid (γ-PGA) is a promising biopolymer for various applications. For glutamic acid-independent strains, the titer of γ-PGA is too low to meet the industrial demand. In this study, we isolated a novel γ-PGA-producing strain, Bacillus tequilensis BL01, and multiple genetic engineering strategies were implemented to improve γ-PGA production. Results First, the one-factor-at-a-time method was used to investigate the influence of carbon and nitrogen sources and temperature on γ-PGA production. The optimal sources of carbon and nitrogen were sucrose and (NH4)2SO4 at 37 °C, respectively. Second, the sucA, gudB, pgdS, and ggt genes were knocked out simultaneously, which increased the titer of γ-PGA by 1.75 times. Then, the titer of γ-PGA increased to 18.0 ± 0.3 g/L by co-overexpression of the citZ and pyk genes in the mutant strain. Furthermore, the γ-PGA titer reached 25.3 ± 0.8 g/L with a productivity of 0.84 g/L/h and a yield of 1.50 g of γ-PGA/g of citric acid in fed-batch fermentation. It should be noted that this study enables the synthesis of low (1.84 × 105 Da) and high (2.06 × 106 Da) molecular weight of γ-PGA by BL01 and the engineering strain. Conclusion The application of recently published strategies to successfully improve γ-PGA production for the new strain B. tequilensis BL01 is reported. The titer of γ-PGA increased 2.17-fold and 1.32-fold compared with that of the wild type strain in the flask and 5 L fermenter. The strain shows excellent promise as a γ-PGA producer compared with previous studies. Meanwhile, different molecular weights of γ-PGA were obtained, enhancing the scope of application in industry.

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Section: Resultsmentioning

confidence: 99%

Engineering of a newly isolated Bacillus tequilensis BL01 for poly-γ-glutamic acid production from citric acid

Wang

Zhou

et al. 2022

Microb Cell Fact

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“…The bacterial Vitreoscilla hemoglobin (VHb) was initially identified in Vitreoscilla sp., in which it functions in oxygen binding. Structurally, the binding pocket of VHb reduces oxygen overflow, which optimizes its ability to deliver oxygen to various partner proteins . Zhang et al were the first to introduce VHb into M. alpina for enhanced ARA production.…”

Section: Metabolic Engineering Strategies For Enhancing Ara Accumulationmentioning

confidence: 99%

“…Structurally, the binding pocket of VHb reduces oxygen overflow, which optimizes its ability to deliver oxygen to various partner proteins. 44 higher ARA titer of 7.89 g L −1 at the cost of a decreased ratio of C16:0 to C18:1. 45 Subsequently, another bacterial hemoglobin from Sinorhizobium meliloti (SHb) was introduced into M. circinelloides.…”

Section: Improving the Efficiency Of Cellular Oxygen Utilizationmentioning

confidence: 99%

Recent Development of Advanced Biotechnology in the Oleaginous Fungi for Arachidonic Acid Production

Guo

Peng

et al. 2022

ACS Synth. Biol.

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Arachidonic acid is an essential ω-6 polyunsaturated fatty acid, which plays a significant role in cardiovascular health and neurological development, leading to its wide use in the food and pharmaceutical industries. Traditionally, ARA is obtained from deep-sea fish oil. However, this source is limited by season and is depleting the already threatened global fish stocks. With the rapid development of synthetic biology in recent years, oleaginous fungi have gradually attracted increasing attention as promising microbial sources for large-scale ARA production. Numerous advanced technologies including metabolic engineering, dynamic regulation of fermentation conditions, and multiomics analysis were successfully adapted to increase ARA synthesis. This review summarizes recent advances in the bioengineering of oleaginous fungi for ARA production. Finally, perspectives for future engineering approaches are proposed to further improve the titer yield and productivity of ARA.

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“…This phenomenon coincides with the highest rate of oxygen consumption, above this value, overflow metabolism is evident. In summary, acetic acid production has been related to the saturation of TCA and respiratory chain capacity, as well as insufficient coenzymes replenishment [2][3][4][5][6]. Since acetate is a toxic compound, its accumulation has a negative effect on E. coli growth and productivity [7,8].…”

Section: Introductionmentioning

confidence: 99%

Glucose consumption rate-dependent transcriptome profiling of Escherichia coli provides insight on performance as microbial factories

et al. 2022

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Background The modification of glucose import capacity is an engineering strategy that has been shown to improve the characteristics of Escherichia coli as a microbial factory. A reduction in glucose import capacity can have a positive effect on production strain performance, however, this is not always the case. In this study, E. coli W3110 and a group of four isogenic derivative strains, harboring single or multiple deletions of genes encoding phosphoenolpyruvate:sugar phosphotransferase system (PTS)-dependent transporters as well as non-PTS transporters were characterized by determining their transcriptomic response to reduced glucose import capacity. Results These strains were grown in bioreactors with M9 mineral salts medium containing 20 g/L of glucose, where they displayed specific growth rates ranging from 0.67 to 0.27 h−1, and specific glucose consumption rates (qs) ranging from 1.78 to 0.37 g/g h. RNA-seq analysis revealed a transcriptional response consistent with carbon source limitation among all the mutant strains, involving functions related to transport and metabolism of alternate carbon sources and characterized by a decrease in genes encoding glycolytic enzymes and an increase in gluconeogenic functions. A total of 107 and 185 genes displayed positive and negative correlations with qs, respectively. Functions displaying positive correlation included energy generation, amino acid biosynthesis, and sugar import. Conclusion Changes in gene expression of E. coli strains with impaired glucose import capacity could be correlated with qs values and this allowed an inference of the physiological state of each mutant. In strains with lower qs values, a gene expression pattern is consistent with energy limitation and entry into the stationary phase. This physiological state could explain why these strains display a lower capacity to produce recombinant protein, even when they show very low rates of acetate production. The comparison of the transcriptomes of the engineered strains employed as microbial factories is an effective approach for identifying favorable phenotypes with the potential to improve the synthesis of biotechnological products.

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Vitreoscilla Haemoglobin: A Tool to Reduce Overflow Metabolism

Cited by 9 publications

References 88 publications

Engineering of a newly isolated Bacillus tequilensis BL01 for poly-γ-glutamic acid production from citric acid

Engineering of a newly isolated Bacillus tequilensis BL01 for poly-γ-glutamic acid production from citric acid

Recent Development of Advanced Biotechnology in the Oleaginous Fungi for Arachidonic Acid Production

Glucose consumption rate-dependent transcriptome profiling of Escherichia coli provides insight on performance as microbial factories

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