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15 results on '"Liu, Mengsu"'

10. Two-stage oxygen supply strategy for enhancing fed-batch production of pyrroloquinoline quinone in Hyphomicrobium denitrificans FJNU-6

Author

Ren Yang, Chongrong Ke, Liu Mengsu, Huaping Xia, Xinwei Yang, and Jianzhong Huang

Subjects
PQQ Cofactor, chemistry.chemical_element, Industrial fermentation, medicine.disease_cause, Applied Microbiology and Biotechnology, Oxygen, 03 medical and health sciences, chemistry.chemical_compound, Industrial Microbiology, Pyrroloquinoline quinone, Biosynthesis, medicine, 030304 developmental biology, 0303 health sciences, 030306 microbiology, General Medicine, Hyphomicrobium denitrificans, Combinatorial chemistry, Biosynthetic Pathways, Kinetics, Hyphomicrobium, chemistry, Batch Cell Culture Techniques, Fermentation, Methanol, Batch production, Oxidation-Reduction, Biotechnology
Abstract

Oxygen is a vital parameter for pyrroloquinoline quinone (PQQ) biosynthesis. In this study, the effects of oxygen supply on the biosynthesis of PQQ were first investigated systematically with Hyphomicrobium denitrificans FJNU-6. Following a kinetic analysis of the specific cell growth rate (μx) and specific PQQ formation rate (μp) in 5 L benchtop fermentation systems at various oxygen supply levels ranging from 0 to 60%, a novel, two-stage oxygen supply strategy was developed for enhancing PQQ production and productivity. Moreover, the transcription of genes involved in methanol oxidation and PQQ biosynthesis was analyzed throughout the process to outline the effect of oxygen supply on cell metabolism. Furthermore, with constant feeding of methanol at 0-1 g/L after the initial methanol was consumed completely, the PQQ concentration and productivity reached 1070 mg/L and 7.64 mg/L/h, respectively, after 140 h in a 5-L fermenter. The two-stage oxygen supply strategy developed in this study provides an effective and economical strategy for the industrial production of PQQ.Key Points• A novel, two-stage oxygen supply strategy was developed for enhancing PQQ production and productivity.•The transcription of genes involved in methanol oxidation and PQQ biosynthesis was regulated by changes in oxygen supply.• This study offers an effective and economical strategy for industrial or large-scale production of PQQ.

Published
2020

11. Preparation and Properties of Novel Asymmetric Gemini Alkyl Polyglycosides

Author

Du Juan, Liu Mengsu, Luo Yan, and Feiyu Chen

Subjects
chemistry.chemical_classification, General Chemical Engineering, 02 engineering and technology, General Chemistry, Epoxy, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, 0104 chemical sciences, chemistry, visual_art, visual_art.visual_art_medium, Organic chemistry, Amine gas treating, 0210 nano-technology, Alkyl
Abstract

In order to obtain higher surface activity and lower foaming ability, novel asymmetric Gemini alkyl polyglycosides were synthetized based on tertiary dodecyl dimethyl amine and epoxy chloropropane by adopting chlorination, substitution, and quaternization reactions. The structure of synthesis product was characterized by using Fourier transform infrared spectroscopy, 1H nuclear magnetic resonance spectroscopy and elemental analysis. It was confirmed that the synthesis product was an asymmetric glycoside quaternary ammonium salt with double ionic head groups. The critical micelle concentration of the resulting product was 0.025 g/mL at 20°C and its surface tension was low to 22.8 mN/m. The emulsifying ability and wettability of the product were the same as or even better than those of the commonly used surfactants. Moreover, the product revealed low foaming ability.

Published
2017

13. High-Level De NovoProduction of (2S)-Eriodictyol in Yarrowia Lipolyticaby Metabolic Pathway and NADPH Regeneration Engineering

Author

Yue, Mingyu, Liu, Mengsu, Gao, Song, Ren, Xuefeng, Zhou, Shenghu, Rao, Yijian, and Zhou, Jingwen

Abstract

(2S)-Eriodictyol, a polyphenolic flavonoid, has found widespread applications in health supplements and food additives. However, the limited availability of plant-derived (2S)-eriodictyol cannot meet the market demand. Microbial production of (2S)-eriodictyol faces challenges, including the low catalytic efficiency of flavone 3′-hydroxylase/cytochrome P450 reductase (F3′H/CPR), insufficient precursor supplementation, and inadequate NADPH regeneration. This study systematically engineered Yarrowia lipolyticafor high-level (2S)-eriodictyol production. In doing this, the expression of F3′H/CPR was balanced, and the supply of precursors was enhanced by relieving feedback inhibition of the shikimate pathway, promoting fatty acid β-oxidation, and increasing the copy number of synthetic pathway genes. These strategies, combined with NADPH regeneration, achieved an (2S)-eriodictyol titer of 423.6 mg/L. Finally, in fed-batch fermentation, a remarkable 6.8 g/L (2S)-eriodictyol was obtained, representing the highest de novomicrobial titer reported to date and paving the way for industrial production.

Published
2024
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14. De NovoSynthesis of Chrysin in Saccharomyces cerevisiae

Author

Xu, Weiqi, Liu, Mengsu, Li, Hongbiao, Chen, Jian, and Zhou, Jingwen

Abstract

Chrysin, a flavonoid, has been found to have been widely used in the health food field. But at present, chrysin production is hindered by the low availability of precursors and the lack of catalytic enzymes with high activity. Therefore, ZmPAL was initially screened to synthesize trans-cinnamic acid with high catalytic activity and specificity. To enhance the supply of precursors, the shikimic acid and chorismic acid pathway genes were overexpressed. Besides, the expression of the intracellular and mitochondrial carbon metabolism genes CIT, MAC1/3, CTP1, YHM2, RtME, and MDHwas enhanced to increase the intracellular acetyl-CoA content. Chrysin was synthesized through a novel gene combination of ScCPR–EbFNSI-1 and PcFNSI. Finally, de novosynthesis of chrysin was achieved, reaching 41.9 mg/L, which is the highest reported concentration to date. In summary, we identified efficient enzymes for chrysin production and increased it by regulating acetyl-CoA metabolism in mitochondria and the cytoplasm, laying a foundation for future large-scale production.

Published
2024
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15. High-Level De Novo Production of (2 S )-Eriodictyol in Yarrowia Lipolytica by Metabolic Pathway and NADPH Regeneration Engineering.

Author

Yue M, Liu M, Gao S, Ren X, Zhou S, Rao Y, and Zhou J

Subjects
NADP metabolism, Metabolic Engineering, Metabolic Networks and Pathways, Yarrowia genetics, Yarrowia metabolism, Flavanones
Abstract

(2 S )-Eriodictyol, a polyphenolic flavonoid, has found widespread applications in health supplements and food additives. However, the limited availability of plant-derived (2 S )-eriodictyol cannot meet the market demand. Microbial production of (2 S )-eriodictyol faces challenges, including the low catalytic efficiency of flavone 3'-hydroxylase/cytochrome P450 reductase (F3'H/CPR), insufficient precursor supplementation, and inadequate NADPH regeneration. This study systematically engineered Yarrowia lipolytica for high-level (2 S )-eriodictyol production. In doing this, the expression of F3'H/CPR was balanced, and the supply of precursors was enhanced by relieving feedback inhibition of the shikimate pathway, promoting fatty acid β-oxidation, and increasing the copy number of synthetic pathway genes. These strategies, combined with NADPH regeneration, achieved an (2 S )-eriodictyol titer of 423.6 mg/L. Finally, in fed-batch fermentation, a remarkable 6.8 g/L (2 S )-eriodictyol was obtained, representing the highest de novo microbial titer reported to date and paving the way for industrial production.

Published
2024
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