BIOCHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 3.7
Ying Li,Yu Zeng,Shuo Zhao,Zhen Wang,Li Chen,Kequan Chen
Pyruvate, a pivotal metabolite in the glycolytic pathway, typically confronts substantial barriers to its natural accumulation within microbial cells. This study successfully facilitated the natural accumulation of pyruvate in Actinobacillus succinogenes 130Z by fine-tuning the oxidation-reduction potential (ORP) in the fermentation milieu. A mechanistic exploration revealed that the accumulation of pyruvate was optimized when ORP conditions favorably modulated pyruvate kinase activity and concurrently suppressed succinate dehydrogenase activity. By integrating the influence of metal ions on enzymatic functions with an innovative aluminum ion-mediated ORP control strategy, we achieved a pyruvate yield of 27.54 g/L over 20 hours, which constitutes an 89.54% increase compared to the baseline. Additionally, the production rate of pyruvate reached 1.38 g/L·h. This investigation not only elucidates the metabolic underpinnings that facilitate the natural enrichment of glycolytic intermediates in Actinobacillus succinogenes 130Z but also lays a robust theoretical foundation for the industrial-scale fermentation of pyruvate. Moreover, the capability to efficiently and rapidly concentrate essential platform metabolites within the glycolytic pathway is of paramount significance, potentially propelling forward the research and synthesis of various downstream metabolic products.
研究领域:
微生物学
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生物化学
·
工业发酵
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DOI
高影响因子
BIOTECHNOLOGY LETTERS
·
2024
·
IF 2
Zhao Shuo,Zeng Yu,Li Ying,Wang Zhen,Chen Li,Chen Kequan
This investigation probes the role of the electron mediator, neutral red (NR), in the electrosynthesis process, specifically examining its effect on the production of succinic acid by Actinobacillus succinogenes . Our findings reveal that NR, when integrated into the cell membrane, is pivotal for sustaining MEC efficiency. Nevertheless, it is susceptible to both intrinsic and MECs-induced degradation. Notably, during the exponential growth phase of the bacteria, NR is readily incorporated into the cell membrane. However, the supplemental addition of NR fails to significantly enhance the MEC’s capacity for succinic acid synthesis, no matter what stage of bacterial growth. And significant depletion of membrane-associated NR is not adequately compensated by the NR present in the fermentation liquid. The ORP feedback-regulated MECs adeptly conserve the NR on the cell membrane, which is essential for maintaining the efficiency of long-term electrosynthesis. The presence of NR on the cell membrane is essential for the functionality of MECs, yet its external replenishment hard. Implementing precise electro-potential regulation strategies can effectively diminish the degradation of NR, thus maintaining the system’s efficiency.
研究领域:
微生物学
·
电化学工程
·
生物技术
✓ 已验证
DOI
PubMed
高影响因子
BIORESOURCE TECHNOLOGY
·
2015
·
IF 4.494
Yan Zhao,Weijia Cao,Zhen Wang,Bowen Zhang,Kequan Chen,Pingkai Ouyang
In this study, Actinobacillus succinogenes NJ113 microbial electrolysis cells (MECs) were used to enhance the reducing power responsible for succinic acid production from corncob hydrolysate. During corncob hydrolysate fermentation, electric MECs resulted in a 1.31-fold increase in succinic acid production and a 1.33-fold increase in the reducing power compared with those in non-electric MECs. When the hydrolysate was detoxified by combining Ca(OH) 2 , NaOH, and activated carbon, succinic acid production increased from 3.47 to 6.95 g/l. Using a constant potential of −1.8 V further increased succinic acid production to 7.18 g/l. A total of 18.09 g/l of succinic acid and a yield of 0.60 g/g total sugar were obtained after a 60-h fermentation when NaOH was used as a pH regulator. The improved succinic acid yield from corncob hydrolysate fermentation using A. succinogenes NJ113 in electric MECs demonstrates the great potential of using biomass as a feedstock to cost-effectively produce succinate.
研究领域:
生物工程
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微生物学
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产品关联
DOI
PubMed
高影响因子
Fermentation-Basel
·
2024
·Vol. 10
·期 2
·109
·
IF 3.3
Jieyi Peng,Shuo Zhao,Ying Li,Zhen Wang,Li Chen
Microbial electrochemical systems have shown great value as a means of enhancing the efficiency of fermentation reactions, but at present, there is no reliable means to balance the extracellular electron supply and corresponding intracellular demands in these systems. The current work describes the unique use of an oxidation–reduction-potential (ORP)-level-controlled microbial electrolysis cell (MEC) system to successfully balance the extracellular electron supply and succinic acid fermentation viaA. succinogenes(130Z). The ORP-controlled MEC system with neutral red (NR) yielded a significant increase in succinic acid production (17.21%). The utilization of NR in this MEC system improved the ORP regulatory sensitivity. The optimal approach to the ORP level control was the use of a −400 mV high-voltage electric pulse-based strategy, which increased the yield of succinic acid by 13.08% compared to the control group, and reduced the energy consumption to 52.29% compared to the potentiostatic method. When compared to the −1 V constant potential MEC system, the high-voltage electric pulse-based ORP strategy for the MEC system control provided sufficient electrons to this system while using less electricity (11.96%) and producing 12.48% (74.43 g/L) more succinic acid during fed-batch fermentation. The electronic utilization efficiency of the ORP-controlled MEC system was 192.02%, which was 15.19 times that of the potentiostatic system. The electronic utilization efficiency is significantly increased in the ORP-controlled MEC system. Succinic acid production is ensured by a high-voltage electric pulse-based method, while the influence on cell growth and power consumption are minimized. Fed-batch fermentation with the high-voltage electric pulse-based ORP strategy for MEC system control is noted to be ideal to achieve a further increase in succinic acid concentration and electronic utilization efficiency.
研究领域:
生物工程
·
微生物学
✓ 已验证
DOI
高影响因子
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