Heterologous Expression and Adaptive Evolution of ε-Poly-lysine Synthase Gene in <i>Corynebacterium glutamicum</i>

ε-Poly-L-lysine (ε-PL) is a natural preservative that has excellent properties such as high safety, good antibacterial effect, wide antibacterial spectrum, and high temperature resistance compared to other food preservatives. At present, the main production strain of ε-PL is <i>Streptomyces al...

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Main Authors: Long Pan, Yihang Chen, Aimei Liao, Yinchen Hou, Jihong Huang
Format: Article
Language:English
Published: MDPI AG 2025-01-01
Series:Fermentation
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Online Access:https://www.mdpi.com/2311-5637/11/1/11
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author Long Pan
Yihang Chen
Aimei Liao
Yinchen Hou
Jihong Huang
author_facet Long Pan
Yihang Chen
Aimei Liao
Yinchen Hou
Jihong Huang
author_sort Long Pan
collection DOAJ
description ε-Poly-L-lysine (ε-PL) is a natural preservative that has excellent properties such as high safety, good antibacterial effect, wide antibacterial spectrum, and high temperature resistance compared to other food preservatives. At present, the main production strain of ε-PL is <i>Streptomyces albulus (S. albulus)</i>. Due to the large amount of mycelium and by-products during fermentation, its production cost is much higher than other food preservatives, which seriously hinders the application of ε-PL in the food industry. <i>Corynebacterium glutamicum</i> (<i>C. glutamicum</i>) is a food safety strain that is widely used in the fermentation industry to produce various amino acids. Its ability to produce high amounts of L-lysine can provide sufficient precursor substances for the synthesis of ε-PL, making it an ideal strain for the heterologous expression of ε-PL synthase genes (<i>pls</i>). In this experiment, a recombinant <i>C. glutamicum</i> capable of synthesizing ε-PL and exhibiting certain physiological resistance to ε-PL was obtained by amplifying <i>pls</i> and heterologous expression in <i>C. glutamicum</i> for the first time. Further optimization of the fermentation temperature, initial pH, and inoculation amount of the recombinant strain resulted in an increase in the ε-PL fermentation yield from 0.12 g/L to 0.22 g/L. Finally, through adaptive evolution of the recombinant strain, the ε-PL tolerance of the recombinant strain was increased to 1.3 g/L, and the yield of ε-PL ultimately reached 0.34 g/L, which increased by 54.55% compared to the initial strain. The recombinant <i>C. glutamicum</i> constructed in this study can significantly shorten the fermentation cycle, reduce bacterial volume and the synthesis of secondary metabolites, which is beneficial for the separation and purification of products, thereby further reducing the production cost of ε-PL and accelerating the process of replacing chemical food preservatives with natural food preservatives.
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series Fermentation
spelling doaj-art-e0c59fd6aed6447585d175a38a592fdb2025-01-24T13:32:02ZengMDPI AGFermentation2311-56372025-01-011111110.3390/fermentation11010011Heterologous Expression and Adaptive Evolution of ε-Poly-lysine Synthase Gene in <i>Corynebacterium glutamicum</i>Long Pan0Yihang Chen1Aimei Liao2Yinchen Hou3Jihong Huang4School of Food and Pharmacy, Xuchang University, Xuchang 461000, ChinaHenan Provincial Key Laboratory of Biological Processing and Nutritional Function of Wheat, School of Biological Engineering, Henan University of Technology, Zhengzhou 450001, ChinaSchool of Food and Pharmacy, Xuchang University, Xuchang 461000, ChinaFood Laboratory of Zhongyuan, Luohe 462300, ChinaSchool of Food and Pharmacy, Xuchang University, Xuchang 461000, Chinaε-Poly-L-lysine (ε-PL) is a natural preservative that has excellent properties such as high safety, good antibacterial effect, wide antibacterial spectrum, and high temperature resistance compared to other food preservatives. At present, the main production strain of ε-PL is <i>Streptomyces albulus (S. albulus)</i>. Due to the large amount of mycelium and by-products during fermentation, its production cost is much higher than other food preservatives, which seriously hinders the application of ε-PL in the food industry. <i>Corynebacterium glutamicum</i> (<i>C. glutamicum</i>) is a food safety strain that is widely used in the fermentation industry to produce various amino acids. Its ability to produce high amounts of L-lysine can provide sufficient precursor substances for the synthesis of ε-PL, making it an ideal strain for the heterologous expression of ε-PL synthase genes (<i>pls</i>). In this experiment, a recombinant <i>C. glutamicum</i> capable of synthesizing ε-PL and exhibiting certain physiological resistance to ε-PL was obtained by amplifying <i>pls</i> and heterologous expression in <i>C. glutamicum</i> for the first time. Further optimization of the fermentation temperature, initial pH, and inoculation amount of the recombinant strain resulted in an increase in the ε-PL fermentation yield from 0.12 g/L to 0.22 g/L. Finally, through adaptive evolution of the recombinant strain, the ε-PL tolerance of the recombinant strain was increased to 1.3 g/L, and the yield of ε-PL ultimately reached 0.34 g/L, which increased by 54.55% compared to the initial strain. The recombinant <i>C. glutamicum</i> constructed in this study can significantly shorten the fermentation cycle, reduce bacterial volume and the synthesis of secondary metabolites, which is beneficial for the separation and purification of products, thereby further reducing the production cost of ε-PL and accelerating the process of replacing chemical food preservatives with natural food preservatives.https://www.mdpi.com/2311-5637/11/1/11ε-poly-L-lysine<i>C. glutamicum</i>fermentationadaptive evolution
spellingShingle Long Pan
Yihang Chen
Aimei Liao
Yinchen Hou
Jihong Huang
Heterologous Expression and Adaptive Evolution of ε-Poly-lysine Synthase Gene in <i>Corynebacterium glutamicum</i>
Fermentation
ε-poly-L-lysine
<i>C. glutamicum</i>
fermentation
adaptive evolution
title Heterologous Expression and Adaptive Evolution of ε-Poly-lysine Synthase Gene in <i>Corynebacterium glutamicum</i>
title_full Heterologous Expression and Adaptive Evolution of ε-Poly-lysine Synthase Gene in <i>Corynebacterium glutamicum</i>
title_fullStr Heterologous Expression and Adaptive Evolution of ε-Poly-lysine Synthase Gene in <i>Corynebacterium glutamicum</i>
title_full_unstemmed Heterologous Expression and Adaptive Evolution of ε-Poly-lysine Synthase Gene in <i>Corynebacterium glutamicum</i>
title_short Heterologous Expression and Adaptive Evolution of ε-Poly-lysine Synthase Gene in <i>Corynebacterium glutamicum</i>
title_sort heterologous expression and adaptive evolution of ε poly lysine synthase gene in i corynebacterium glutamicum i
topic ε-poly-L-lysine
<i>C. glutamicum</i>
fermentation
adaptive evolution
url https://www.mdpi.com/2311-5637/11/1/11
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AT yinchenhou heterologousexpressionandadaptiveevolutionofepolylysinesynthasegeneinicorynebacteriumglutamicumi
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