Efficient Production of ��-Poly-L-Lysine by Streptomyces ahygroscopicus Using One-Stage pH Control Fed-Batch Fermentation Coupled with Nutrient Feeding

Abstract Backgrounds: Whey is the major pollution source from the dairy industry. Exploring new outlets for whey utilization is urgently needed to decline its environmental pollution. In this study, we explored the possibility of using whey powder to produce 2,3-butanediol (2,3-BD), an important platform chemical.Results: A Klebsiella oxytoca strain PDL-0 was selected from five 2,3-BD producing strains based on its ability to efficiently produce 2,3-BD from lactose, the major fermentable sugar in whey. Five genes including pox, pta, frdA, ldhD, and pflB were knocked out in K. oxytoca PDL-0 to decrease the production of byproducts like acetate, succinate, lactate, and formate. Using fed-batch fermentation of K. oxytoca PDL-0 ΔpoxΔptaΔfrdAΔldhDΔpflB, 74.9 g/L 2,3-BD was produced with a productivity of 2.27 g/L/h and a yield of 0.43 g/g from lactose. In addition, when whey powder was used as the substrate, 65.5 g/L 2,3-BD was produced within 24 h with a productivity of 2.73 g/L/h and a yield of 0.44 g/g.Conclusion: This study proved the efficiency of K. oxytoca PDL-0 to metabolize whey for 2,3-BD production. Due to its characteristics of non-pathogenicity and efficient lactose utilization, K. oxytoca PDL-0 might also be used in the production of other important chemicals using whey as the substrate.

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A new polysialic acid production process based on dual-stage pH control and fed-batch fermentation for higher yield and resulting high molecular weight product

Applied Microbiology and Biotechnology ◽

10.1007/s00253-012-4503-4 ◽

2012 ◽

Vol 97 (6) ◽

pp. 2405-2412 ◽

Cited By ~ 16

Author(s):

Zhi-Yong Zheng ◽

Shun-Zhi Wang ◽

Guo-Shun Li ◽

Xiao-Bei Zhan ◽

Chi-Chung Lin ◽

...

Keyword(s):

Molecular Weight ◽

Acid Production ◽

Batch Fermentation ◽

Polysialic Acid ◽

Ph Control ◽

Fed Batch ◽

High Molecular Weight Product ◽

Fed Batch Fermentation ◽

Dual Stage ◽

Molecular Weight Product

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Efficient Production of Propionic Acid in the Fed-Batch Fermentation of Propionibacterium acidipropionici and Its Metabolic Flux Analysis

Austin Journal of Nutrition & Metabolism ◽

10.26420/austinjnutrmetab.2021.1112 ◽

2021 ◽

Vol 8 (3) ◽

Author(s):

Zhang Y ◽

◽

Zhang K ◽

Li X ◽

Wang Z ◽

...

Keyword(s):

Propionic Acid ◽

Batch Fermentation ◽

Metabolic Flux ◽

Flux Distribution ◽

Efficient Production ◽

Flux Analysis ◽

Fed Batch ◽

Propionibacterium Acidipropionici ◽

Metabolic Flux Distribution ◽

Fed Batch Fermentation

To improve the fermentation efficiency of Propionibacterium acidipropionici, a simplified metabolic network was established to provide theoretical guidance for medium optimization and process regulation. The effect of glucose and glycerol on propionic acid production and metabolic flux distribution was investigated and the combination of glucose and glycerol was optimized. The results showed that the productivity of propionic acid could be improved by enhancing the synthesis of pyruvate and its flux distribution to the oxaloacetate branch. Finally, the scaled-up fed-batch fermentation of P. acidipropionici was conducted. The concentration of propionic acid reached 51.75 ± 3.62g/L with a glucose/glycerol ratio of 4:1, an improvement of 79.25% relative to the use of glucose alone, and the corresponding productivity and yield were 0.39g/(L· h) and 0.52g/g, respectively. Therefore, the combination of glucose and glycerol significantly improved the productivity of propionic acid and provides a new strategy for industrial production.

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