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Zhu D, Liu Y, Yang H, Zhang J, Zheng G, Zhang H, Wang L, Zhang J, Chen X. Combinatorial strain improvement and bioprocess development for efficient production of ε-poly-L-lysine in Streptomyces albulus. BIORESOURCE TECHNOLOGY 2024; 407:131123. [PMID: 39029766 DOI: 10.1016/j.biortech.2024.131123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 07/09/2024] [Accepted: 07/15/2024] [Indexed: 07/21/2024]
Abstract
ε-Poly-L-lysine (ε-PL) is an amino acid homopolymer with diverse potential applications in the food, pharmaceutical and cosmetic industries. To improve its biomanufacturing efficiency, strain engineering and bioprocess optimization were combined in this study. Firstly, a cocktail strain breeding strategy was employed to generate a ε-PL high-production mutant, Streptomyces albulus GS114, with enhanced L-lysine uptake capability. Subsequently, the L-lysine feeding conditions during fed-batch fermentation were systematically optimized to improve the L-lysine supply, resulting in ε-PL production reaching 73.1 ± 1.4 g/L in 5 L bioreactor. Finally, an engineered strain, S. albulus L2, with enhanced uptake capability and polymerization ability of L-lysine was constructed, achieving ε-PL production of 81.4 ± 5.2 g/L by fed-batch fermentation. This represents the highest reported production of ε-PL to date. This study provided an efficient production strategy for ε-PL and valuable insights into the high-value utilization of L-lysine.
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Affiliation(s)
- Daojun Zhu
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Yuxiang Liu
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Hao Yang
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Jiawei Zhang
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Gencheng Zheng
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Hongjian Zhang
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Liang Wang
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Jianhua Zhang
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Xusheng Chen
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.
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Wang L, Yang H, Wu M, Zhang H, Zhang J, Chen X. Enhanced ε-Poly-L-Lysine Production in Streptomyces albulus through Multi-Omics-Guided Metabolic Engineering. Biomolecules 2024; 14:752. [PMID: 39062465 PMCID: PMC11274744 DOI: 10.3390/biom14070752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2024] [Revised: 06/08/2024] [Accepted: 06/10/2024] [Indexed: 07/28/2024] Open
Abstract
Safe and eco-friendly preservatives are crucial to preventing food spoilage and illnesses, as foodborne diseases caused by pathogens result in approximately 600 million cases of illness and 420,000 deaths annually. ε-Poly-L-lysine (ε-PL) is a novel food preservative widely used in many countries. However, its commercial application has been hindered by high costs and low production. In this study, ε-PL's biosynthetic capacity was enhanced in Streptomyces albulus WG608 through metabolic engineering guided by multi-omics techniques. Based on transcriptome and metabolome data, differentially expressed genes (fold change >2 or <0.5; p < 0.05) and differentially expressed metabolites (fold change >1.2 or <0.8) were separately subjected to gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. The integrative analysis of transcriptome, metabolome, and overexpression revealed the essential roles of isocitrate lyase, succinate dehydrogenase, flavoprotein subunit, diaminopimelate dehydrogenase, polyphosphate kinase, and polyP:AMP phosphotransferase in ε-PL biosynthesis. Subsequently, a strain with enhanced ATP supply, L-lysine supply, and ε-PL synthetase expression was constructed to improve its production. Finally, the resulting strain, S. albulus WME10, achieved an ε-PL production rate of 77.16 g/L in a 5 L bioreactor, which is the highest reported ε-PL production to date. These results suggest that the integrative analysis of the transcriptome and metabolome can facilitate the identification of key pathways and genetic elements affecting ε-PL synthesis, guiding further metabolic engineering and thus significantly enhancing ε-PL production. The method presented in this study could be applicable to other valuable natural antibacterial agents.
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Affiliation(s)
| | | | | | | | | | - Xusheng Chen
- Key Laboratory of Industrial Biotechnology, School of Biotechnology, Jiangnan University, Ministry of Education, Wuxi 214122, China; (L.W.); (M.W.); (J.Z.)
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Li S, Wang N, Li X. Enhancement of poly‑γ‑L‑diaminobutanoic acid production in Bacillus pumilus by repeated pH shocks. Bioprocess Biosyst Eng 2024:10.1007/s00449-024-03050-z. [PMID: 38904716 DOI: 10.1007/s00449-024-03050-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 06/17/2024] [Indexed: 06/22/2024]
Abstract
This study investigated the effect of pH on poly-γ-L-diaminobutanoic acid (γ-PAB) production by Bacillus pumilus in batch fermentation. In the natural fermentation where pH was not controlled, pH decreased from initial 7.0 to 3.0 in 18 h and γ-PAB production was 428.6 mg/L. In the pH-controlled fermentation, B. pumilus tended to proliferation at higher pH, while γ-PAB synthesis was favorable at lower pH, in which the optimal pH for γ-PAB production was 4.2, and γ-PAB yield reached 2284.5 mg/L. Adopting a pH shock strategy which lasted 9 h in the pre-fermentation phase, biomass (OD600) and γ-PAB yield of B. pumilus were obtained as 61.3 and 2794.6 mg/L, respectively, which were 10.8% and 22.4% higher than those in batch fermentation without pH shock. Subsequent fermentation of repeated pH shocks showed that a further higher productivity could be achieved, in which the final OD600 reached 65.1, and γ-PAB production reached as high as 3482.3 mg/L, which were increased by 6.2% and 17.1% compared with those in single pH shock, respectively. This study demonstrated that B. pumilus can synthesize more γ-PAB at suboptimal pH and provided a novel approach to regulate γ-PAB synthesis.
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Affiliation(s)
- Shu Li
- Marine College, Shandong University, Weihai, 264209, Shandong, China.
| | - Nan Wang
- Food and Drug Inspection, Testing Institute at Weihai, Weihai, 264210, Shandong, China
| | - Xiaoting Li
- Key Laboratory of Modern Marine Ranching Technology of Weihai, Weihai, 264209, Shandong, China
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Li S, Wang N, Zhang M, Li X. Enhanced ε‑poly‑L‑lysine production in Streptomyces species by combining interspecific hybridization with multiple antibiotic resistance. Bioprocess Biosyst Eng 2024; 47:519-532. [PMID: 38499687 DOI: 10.1007/s00449-024-02983-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Accepted: 02/09/2024] [Indexed: 03/20/2024]
Abstract
To improve the ε-PL production in wild-type strains of Streptomyces. albulus, Streptomyces. noursei, Streptomyces. rochei and Streptomyces. yunnanensis, the interspecific hybridization based on protoplast fusion was first performed. Two-species hybridizations failed to obtain hybrids with significant increase in ε-PL production, but four-species hybridizations succeed in acquiring many high-yield hybrids. 16S rDNA homology alignment and RAPD confirmed that the hybrid HX17 was restructured by integrating gene fragments from S. albulus and S. rochei with S. noursei as the carrier. S. noursei HX17 was subsequently suffered from mutagenesis and genome shuffling combining with multiple antibiotic resistance, and a mutant S. noursei GX6 was obtained with ε-PL yield of 2.23 g/L in shake-flask fermentation. In fed-batch fermentation, the ε-PL production of GX6 reached 47.2 g/L, which was increased by 95.6% to 136.8% over the wild parents. Ribosomal genes associated with antibiotics were sequenced and majority of mutant strains had mutations at different sites, indicating that the increase of antibiotic resistance was strongly associated with them. This research proved that combining interspecific hybridization with multiple antibiotic resistance was as an effective approach to rapidly improve the ε-PL production in Streptomyces species.
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Affiliation(s)
- Shu Li
- Marine College, Shandong University, Weihai, 264209, Shandong, China.
| | - Nan Wang
- Food and Drug Inspection and Testing Institute at Weihai, Shandong, 264210, China
| | - Meichao Zhang
- Food and Drug Inspection and Testing Institute at Weihai, Shandong, 264210, China
| | - Xiaoting Li
- Marine College, Shandong University, Weihai, 264209, Shandong, China
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Qiu Y, Xu D, Lei P, Li S, Xu H. Engineering functional homopolymeric amino acids: from biosynthesis to design. Trends Biotechnol 2024; 42:310-325. [PMID: 37775417 DOI: 10.1016/j.tibtech.2023.08.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 08/08/2023] [Accepted: 08/31/2023] [Indexed: 10/01/2023]
Abstract
Homopolymeric amino acids (HPAs) are a class of microbial polymers that can be classified into two categories: anionic and cationic HPAs. Notable examples include γ-poly-glutamic acid (γ-PGA) and ε-poly-L-lysine (ε-PL) that have wide-ranging applications in medicine, food, and agriculture. The primary method of manufacture is through microbial synthesis. In recent decades significant efforts have been made to enhance the production of HPAs, specifically focusing on γ-PGA and ε-PL. We comprehensively review current advances in understanding the synthetic mechanisms as well as metabolic engineering and fermentation process techniques to improve the production of HPAs. In addition, we discuss the major challenges and solutions associated with desired structure regulation of HPAs and the development of novel structures.
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Affiliation(s)
- Yibin Qiu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, PR China
| | - Delei Xu
- College of Biological and Food Engineering, Changshu Institute of Technology, 99 South Third Ring Road, Changshu 215500, PR China
| | - Peng Lei
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, PR China
| | - Sha Li
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, PR China.
| | - Hong Xu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, PR China; Nanjing Shineking Biotech Co. Ltd., Nanjing 210061, PR China.
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Wang Y, Wang L, Hu Y, Qin J, Yu B. Design and optimization of ε-poly-l-lysine with specific functions for diverse applications. Int J Biol Macromol 2024; 262:129513. [PMID: 38262828 DOI: 10.1016/j.ijbiomac.2024.129513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 01/03/2024] [Accepted: 01/13/2024] [Indexed: 01/25/2024]
Abstract
ε-Poly-l-lysine (ε-PL) is a natural homo-poly(amino acid) which can be produced by microorganisms. With the advantages in broad-spectrum antimicrobial activity, biodegradability, and biocompatibility, ε-PL has been widely used as a preservative in the food industry. Different molecular architectures endow ε-PL and ε-PL-based materials with versatile applications. However, the microbial synthesis of ε-PL is currently limited by low efficiencies in genetic engineering and molecular architecture modification. This review presents recent advances in ε-PL production and molecular architecture modification of microbial ε-PL, with a focus on the current challenges and solutions for the improvement of the productivity and diversity of ε-PL. In addition, we highlight recent examples where ε-PL has been applied to expand the versability of edible films and nanoparticles in various applications. Commercial production and the challenges and future research directions in ε-PL biosynthesis are also discussed. Currently, although the main use of ε-PL is as a food preservative, ε-PL and ε-PL-based polymers have shown excellent application potential in biomedical fields. With the development of synthetic biology, the design and synthesis of ε-PL with a customized molecular architecture are possible in the near future. ε-PL-based polymers with specific functions will be a new trend in biopolymer manufacturing.
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Affiliation(s)
- Yi Wang
- CAS Key Laboratory of Microbial Physiological & Metabolic Engineering, State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Limin Wang
- CAS Key Laboratory of Microbial Physiological & Metabolic Engineering, State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
| | - Yangfan Hu
- CAS Key Laboratory of Microbial Physiological & Metabolic Engineering, State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Jiayang Qin
- College of Pharmacy, Binzhou Medical University, Yantai 264003, China.
| | - Bo Yu
- CAS Key Laboratory of Microbial Physiological & Metabolic Engineering, State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
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Hagh Ranjbar H, Hosseini-Abari A, Ghasemi SM, Hafezi Birgani Z. Antibacterial activity of epsilon-poly-l-lysine produced by Stenotrophomonas maltophilia HS4 and Paenibacillus polymyxa HS5, alone and in combination with bacteriophages. MICROBIOLOGY (READING, ENGLAND) 2023; 169:001363. [PMID: 37477972 PMCID: PMC10433424 DOI: 10.1099/mic.0.001363] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 07/04/2023] [Indexed: 07/22/2023]
Abstract
Over the past decades, antibiotic resistance has become a major clinical problem, and searching for new therapeutic strategies seems to be necessary. Using novel natural compounds, antimicrobial peptides, and bacteriophages is the most promising solution. In this study, various cationic metabolite-producer bacteria were isolated from different soil samples. Two isolates were identified as Stenotrophomonas maltophilia HS4 (accession number: MW791428) and Paenibacillus polymyxa HS5 (accession number: MW791430) based on biochemical characteristics and phylogenetic analysis using 16S rRNA gene sequences. The cationic compound in the fermentation broth was precipitated and purified with sodium tetraphenylborate salt. The purified cationic peptide was confirmed to be epsilon-poly-l-lysine by structural and molecular analysis using High-Performance Liquid Chromatography, Sodium dodecyl-sulfate-polyacrylamide gel electrophoresis, and Fourier-transform infrared spectroscopy. The antibacterial activity of epsilon-poly-l-lysine was evaluated against Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, Enterococcus faecalis ATCC 29212, Serratia marcescens ATCC 13880, and Klebsiella pneumoniae ATCC 13883 by microdilution method. Furthermore, the antibacterial effects of purified epsilon-poly-l-lysine in combination with two long non-contractile tail bacteriophages against vancomycin-resistant Enterococcus faecalis and colistin-resistant Klebsiella pneumoniae were investigated. The results indicated great antibacterial activity of epsilon-poly-l-lysine which was produced by two novel bacteria. The epsilon-poly-l-lysine as a potent cationic antimicrobial peptide is demonstrated to possess great antimicrobial activity against pathogenic and also antibiotic-resistant bacteria.
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Affiliation(s)
- Hamidreza Hagh Ranjbar
- Department of Cell and Molecular Biology & Microbiology, Faculty of Biological Science and Technology, University of Isfahan, Isfahan, Iran
| | - Afrouzossadat Hosseini-Abari
- Department of Cell and Molecular Biology & Microbiology, Faculty of Biological Science and Technology, University of Isfahan, Isfahan, Iran
| | - Seyed Mahdi Ghasemi
- Department of Microbiology, Faculty of Biological Sciences and Technology, Shahid Ashrafi Esfahani University, Isfahan, Iran
| | - Zahra Hafezi Birgani
- Department of Microbiology, Faculty of Biological Sciences and Technology, Shahid Ashrafi Esfahani University, Isfahan, Iran
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Yang H, Zhu D, Kai L, Wang L, Zhang H, Zhang J, Chen X. Engineering Streptomyces albulus to enhance ε-poly-L-lysine production by introducing a polyphosphate kinase-mediated ATP regeneration system. Microb Cell Fact 2023; 22:51. [PMID: 36918890 PMCID: PMC10012588 DOI: 10.1186/s12934-023-02057-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 03/07/2023] [Indexed: 03/16/2023] Open
Abstract
BACKGROUND ε-Poly-L-lysine (ε-PL) is a natural and safe food preservative that is mainly produced by filamentous and aerobic bacteria Streptomyces albulus. During ε-PL biosynthesis, a large amount of ATP is used for the polymerization of L-lysine. A shortage of intracellular ATP is one of the major factors limiting the increase in ε-PL production. In previous studies, researchers have mainly tried to increase the oxygen supply to enhance intracellular ATP levels to improve ε-PL production, which can be achieved through the use of two-stage dissolved oxygen control, oxygen carriers, heterologous expression of hemoglobin, and supplementation with auxiliary energy substrates. However, the enhancement of the intracellular ATP supply by constructing an ATP regeneration system has not yet been considered. RESULTS In this study, a polyphosphate kinase (PPK)-mediated ATP regeneration system was developed and introduced into S. albulus to successfully improve ε-PL production. First, polyP:AMP phosphotransferase (PAP) from Acinetobacter johnsonii was selected for catalyzing the conversion of AMP into ADP through an in vivo test. Moreover, three PPKs from different microbes were compared by in vitro and in vivo studies with respect to catalytic activity and polyphosphate (polyP) preference, and PPK2Bcg from Corynebacterium glutamicum was used for catalyzing the conversion of ADP into ATP. As a result, a recombinant strain PL05 carrying coexpressed pap and ppk2Bcg for catalyzing the conversion of AMP into ATP was constructed. ε-PL production of 2.34 g/L was achieved in shake-flask fermentation, which was an increase of 21.24% compared with S. albulus WG608; intracellular ATP was also increased by 71.56%. In addition, we attempted to develop a dynamic ATP regulation route, but the result was not as expected. Finally, the conditions of polyP6 addition were optimized in batch and fed-batch fermentations, and the maximum ε-PL production of strain PL05 in a 5-L fermenter was 59.25 g/L by fed-batch fermentation, which is the highest ε-PL production reported in genetically engineered strains. CONCLUSIONS In this study, we proposed and developed a PPK-mediated ATP regeneration system in S. albulus for the first time and significantly enhanced ε-PL production. The study provides an efficient approach to improve the production of not only ε-PL but also other ATP-driven metabolites.
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Affiliation(s)
- Hao Yang
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
| | - Daojun Zhu
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
| | - Lang Kai
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
| | - Liang Wang
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
| | - Hongjian Zhang
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
| | - Jianhua Zhang
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
| | - Xusheng Chen
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.
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Influence of Low-Intensity Ultrasound on ε-Polylysine Production: Intracellular ATP and Key Biosynthesis Enzymes during Streptomyces albulus Fermentation. Foods 2022; 11:foods11213525. [DOI: 10.3390/foods11213525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 10/29/2022] [Accepted: 11/01/2022] [Indexed: 11/09/2022] Open
Abstract
The effect of low-intensity sonication treatment on cell growth, ε-polylysine (ε-PL) yield and its biological mechanism were investigated, using a 3-L-jar fermenter coupled with an in situ ultrasonic slot with a Streptomyces albulus strain SAR 14-116. Under ultrasonic conditions (28 kHz, 0.37 W cm−2, 60 min), a high biomass of SAR 14-116 and concentration of ε-PL were realized (i.e., they increased by 14.92% and 28.45%, respectively) when compared with a control. Besides this, ultrasonication increased the mycelia viability and intracellular ATP as well as activities of key enzymes involved in the ε-PL biosynthesis pathway, resulting in an improvement in the production of ε-PL. Data on qRT-PCR revealed that ultrasonication also affected the gene expression of key enzymes in the ε-PL biosynthesis pathway, including ε-PL synthetase (PLS). These outcomes provided the basis for understanding the effects of ultrasound-assisted fermentation on the stimulation of metabolite production and fermentation procedure in a fermenter.
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Lian C, Zhang M, Mao J, Liu Y, Wang X, Kong L, Yao Q, Qin J. Transcriptomic and metabolomic analyses for providing insights into the influence of polylysine synthetase on the metabolism of Streptomyces albulus. Microb Cell Fact 2022; 21:224. [PMID: 36307825 DOI: 10.1186/s12934-022-01953-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 10/16/2022] [Indexed: 11/10/2022] Open
Abstract
ε-poly-L-lysine (ε-PL) is the main secondary metabolite of Streptomyces albulus, and it is widely used in the food industry. Polylysine synthetase (Pls) is the last enzyme in the ε-PL biosynthetic pathway. Our previous study revealed that Pls overexpressed in S. albulus CICC11022 result in the efficient production of ε-PL. In this study, a Pls gene knockout strain was initially constructed. Then, genomic, transcriptomic and metabolomic approaches were integrated to study the effects of the high expression and knockout of Pls on the gene expression and metabolite synthesis of S. albulus. The high expression of Pls resulted in 598 significantly differentially expressed genes (DEGs) and 425 known differential metabolites, whereas the inactivation of Pls resulted in 868 significant DEGs and 374 known differential metabolites. The expressions of 8 and 35 genes were negatively and positively associated with the Pls expression, respectively. Subsequently, the influence mechanism of the high expression and inactivation of Pls on the ε-PL biosynthetic pathway was elucidated. Twelve metabolites with 30% decreased yield in the high-expression strain of Pls but 30% increased production in the Pls knockout strain were identified. These results demonstrate the influence of Pls on the metabolism of S. albulus. The present work can provide the theoretical basis for improving the production capacity of ε-PL by means of metabolic engineering or developing bioactive substances derived from S. albulus.
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Affiliation(s)
- Congcong Lian
- College of Pharmacy, Binzhou Medical University, Yantai, 264003, People's Republic of China
| | - Min Zhang
- College of Pharmacy, Binzhou Medical University, Yantai, 264003, People's Republic of China
| | - Jiaqi Mao
- College of Pharmacy, Binzhou Medical University, Yantai, 264003, People's Republic of China
| | - Yuanyu Liu
- College of Pharmacy, Binzhou Medical University, Yantai, 264003, People's Republic of China
| | - Xiuwen Wang
- College of Pharmacy, Binzhou Medical University, Yantai, 264003, People's Republic of China
| | - Linghui Kong
- College of Pharmacy, Binzhou Medical University, Yantai, 264003, People's Republic of China
| | - Qingshou Yao
- College of Pharmacy, Binzhou Medical University, Yantai, 264003, People's Republic of China.
| | - Jiayang Qin
- College of Pharmacy, Binzhou Medical University, Yantai, 264003, People's Republic of China.
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Fu J, Li C, Ju X, Bai J, Zhou Y, Zhang Y, Wang Y, Sun Z, Hu C, Li L, Ji L. Efficient production of ε-poly-l-lysine from cassava bagasse hydrolysate used as carbon source by Streptomyces albulus US3-18. Bioprocess Biosyst Eng 2022; 45:1407-1419. [DOI: 10.1007/s00449-022-02755-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 07/06/2022] [Indexed: 11/02/2022]
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12
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Li S, Mao Y, Zhang L, Wang M, Meng J, Liu X, Bai Y, Guo Y. Recent advances in microbial ε-poly-L-lysine fermentation and its diverse applications. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2022; 15:65. [PMID: 35710433 PMCID: PMC9205021 DOI: 10.1186/s13068-022-02166-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 06/08/2022] [Indexed: 06/15/2023]
Abstract
The naturally occurring homo-polyamide biopolymer, ε-poly-L-lysine (ε-PL) consists of 25-35 L-lysine residues with amide linkages between α-carboxyl groups and ε-amino groups. ɛ-PL exhibits several useful properties because of its unusual structure, such as biodegradability, water solubility, no human toxicity, and broad-spectrum antibacterial activities; it is widely applied in the fields of food, medicine, clinical chemistry and electronics. However, current industrial production of ε-PL is only performed in a few countries. Based on an analysis of the physiological characteristics of ε-PL fermentation, current advances that enhance ε-PL fermentation, from strain improvement to product isolation are systematically reviewed, focusing on: (1) elucidating the metabolic pathway and regulatory mechanism of ε-PL synthesis; (2) enhancing biosynthetic performance through mutagenesis, fermentation optimization and metabolic engineering; and (3) understanding and improving the biological activity and functional properties of ε-PL. Finally, perspectives on engineering and exploiting ε-PL as a source material for the production of various advanced materials are also discussed, providing scientific guidelines for researchers to further improve the ε-PL fermentation process.
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Affiliation(s)
- Shubo Li
- College of Light Industry and Food Engineering, Guangxi University, Nanning, 530004, China
| | - Yunren Mao
- College of Light Industry and Food Engineering, Guangxi University, Nanning, 530004, China
| | - Lifei Zhang
- College of Light Industry and Food Engineering, Guangxi University, Nanning, 530004, China
| | - Miao Wang
- College of Light Industry and Food Engineering, Guangxi University, Nanning, 530004, China
| | - Jinhao Meng
- College of Light Industry and Food Engineering, Guangxi University, Nanning, 530004, China
| | - Xiaoling Liu
- College of Light Industry and Food Engineering, Guangxi University, Nanning, 530004, China
| | - Yunxia Bai
- College of Light Industry and Food Engineering, Guangxi University, Nanning, 530004, China
| | - Yuan Guo
- National Engineering Research Center for Non-Food Biorefinery, Guangxi Academy of Sciences, Nanning, 530004, China.
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13
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Biotechnological production and application of epsilon-poly-L-lysine (ε-PL): biosynthesis and its metabolic regulation. World J Microbiol Biotechnol 2022; 38:123. [PMID: 35637397 DOI: 10.1007/s11274-022-03304-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 05/06/2022] [Indexed: 10/18/2022]
Abstract
Epsilon-poly-L-lysine (ε-PL) is an unusual biopolymer composed of L-lysine produced by several microorganisms, especially by the genus Streptomyces. Due to its excellent antimicrobial activity, good water solubility, high safety, and biodegradable nature, ε-PL with a GRAS status has been widely used in food and pharmaceutical industries. In the past years, studies have focused on the biotechnological production of ɛ-PL, the biosynthetic mechanism of microbial ɛ-PL, and its application. To provide new perspectives from recent advances, the review introduced the methods for the isolation of ɛ-PL producing strains and the biosynthetic mechanism of microbial ɛ-PL. We summarized the strategies for the improvement of ɛ-PL producing strains, including physical and chemical mutagenesis, ribosome engineering and gene engineering, and compared the different metabolic regulation strategies for improving ɛ-PL production, including medium optimization, nutrient supply, pH control, and dissolved oxygen control. Then, the downstream purification methods of ɛ-PL and its recent applications in food and medicine industries were introduced. Finally, we also proposed the potential challenges and the perspectives for the production of ε-PL.
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Efficient ε-poly-L-lysine production by Streptomyces albulus based on a dynamic pH-regulation strategy. Process Biochem 2022. [DOI: 10.1016/j.procbio.2022.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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15
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Huang R, Liu H, Zhao W, Wang S, Wang S, Cai J, Yang C. AdpA, a developmental regulator, promotes ε-poly-l-lysine biosynthesis in Streptomyces albulus. Microb Cell Fact 2022; 21:60. [PMID: 35397580 PMCID: PMC8994273 DOI: 10.1186/s12934-022-01785-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 03/31/2022] [Indexed: 12/01/2022] Open
Abstract
Background AdpA is a global regulator of morphological differentiation and secondary metabolism in Streptomyces, but the regulatory roles of the Streptomyces AdpA family on the biosynthesis of the natural product ε-poly-l-lysine (ε-PL) remain unidentified, and few studies have focused on increasing the production of ε-PL by manipulating transcription factors in Streptomyces. Results In this study, we revealed the regulatory roles of different AdpA homologs in ε-PL biosynthesis and morphological differentiation and effectively promoted ε-PL production and sporulation in Streptomycesalbulus NK660 by heterologously expressing adpA from S.neyagawaensis NRRLB-3092 (adpASn). First, we identified a novel AdpA homolog named AdpASa in S.albulus NK660 and characterized its function as an activator of ε-PL biosynthesis and morphological differentiation. Subsequently, four heterologous AdpA homologs were selected to investigate their phylogenetic relationships and regulatory roles in S.albulus, and AdpASn was demonstrated to have the strongest ability to promote both ε-PL production and sporulation among these five AdpA proteins. The ε-PL yield of S.albulus heterologously expressing adpASn was approximately 3.6-fold higher than that of the control strain. Finally, we clarified the mechanism of AdpASn in enhancing ε-PL biosynthesis and its effect on ε-PL polymerization degree using real-time quantitative PCR, microscale thermophoresis and MALDI-TOF–MS. AdpASn was purified, and its seven direct targets, zwf, tal, pyk2, pta, ack, pepc and a transketolase gene (DC74_2409), were identified, suggesting that AdpASn may cause the redistribution of metabolic flux in central metabolism pathways, which subsequently provides more carbon skeletons and ATP for ε-PL biosynthesis in S.albulus. Conclusions Here, we characterized the positive regulatory roles of Streptomyces AdpA homologs in ε-PL biosynthesis and their effects on morphological differentiation and reported for the first time that AdpASn promotes ε-PL biosynthesis by affecting the transcription of its target genes in central metabolism pathways. These findings supply valuable insights into the regulatory roles of the Streptomyces AdpA family on ε-PL biosynthesis and morphological differentiation and suggest that AdpASn may be an effective global regulator for enhanced production of ε-PL and other valuable secondary metabolites in Streptomyces. Supplementary Information The online version contains supplementary material available at 10.1186/s12934-022-01785-6.
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Zong G, Fu J, Zhang P, Zhang W, Xu Y, Cao G, Zhang R. Use of elicitors to enhance or activate the antibiotic production in streptomyces. Crit Rev Biotechnol 2021; 42:1260-1283. [PMID: 34706600 DOI: 10.1080/07388551.2021.1987856] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Streptomyces is the largest and most significant genus of Actinobacteria, comprising 961 species. These Gram-positive bacteria produce many versatile and important bioactive compounds; of these, antibiotics, specifically the enhancement or activation of their production, have received extensive research attention. Recently, various biotic and abiotic elicitors have been reported to modify the antibiotic metabolism of Streptomyces, which promotes the production of new antibiotics and bioactive metabolites for improvement in the yields of endogenous products. However, some elicitors that obviously contribute to secondary metabolite production have not yet received sufficient attention. In this study, we have reviewed the functions and mechanisms of chemicals, novel microbial metabolic elicitors, microbial interactions, enzymes, enzyme inhibitors, environmental factors, and novel combination methods regarding antibiotic production in Streptomyces. This review has aimed to identify potentially valuable elicitors for stimulating the production of latent antibiotics or enhancing the synthesis of subsistent antibiotics in Streptomyces. Future applications and challenges in the discovery of new antibiotics and enhancement of existing antibiotic production using elicitors are discussed.
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Affiliation(s)
- Gongli Zong
- Key Laboratory of Industrial Biotechnology of Ministry of Education & School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, China.,Biomedical Sciences College & Shandong Medicinal Biotechnology Centre, Shandong First Medical University & Shandong Academy of Medical Sciences, Ji'nan, China
| | - Jiafang Fu
- Biomedical Sciences College & Shandong Medicinal Biotechnology Centre, Shandong First Medical University & Shandong Academy of Medical Sciences, Ji'nan, China
| | - Peipei Zhang
- Biomedical Sciences College & Shandong Medicinal Biotechnology Centre, Shandong First Medical University & Shandong Academy of Medical Sciences, Ji'nan, China
| | - Wenchi Zhang
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Yan Xu
- Key Laboratory of Industrial Biotechnology of Ministry of Education & School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, China
| | - Guangxiang Cao
- Biomedical Sciences College & Shandong Medicinal Biotechnology Centre, Shandong First Medical University & Shandong Academy of Medical Sciences, Ji'nan, China
| | - Rongzhen Zhang
- Key Laboratory of Industrial Biotechnology of Ministry of Education & School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, China
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Wang L, Zhang C, Zhang J, Rao Z, Xu X, Mao Z, Chen X. Epsilon-poly-L-lysine: Recent Advances in Biomanufacturing and Applications. Front Bioeng Biotechnol 2021; 9:748976. [PMID: 34650962 PMCID: PMC8506220 DOI: 10.3389/fbioe.2021.748976] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 09/15/2021] [Indexed: 11/30/2022] Open
Abstract
ε-poly-L-lysine (ε-PL) is a naturally occurring poly(amino acid) of varying polymerization degree, which possesses excellent antimicrobial activity and has been widely used in food and pharmaceutical industries. To provide new perspectives from recent advances, this review compares several conventional and advanced strategies for the discovery of wild strains and development of high-producing strains, including isolation and culture-based traditional methods as well as genome mining and directed evolution. We also summarize process engineering approaches for improving production, including optimization of environmental conditions and utilization of industrial waste. Then, efficient downstream purification methods are described, including their drawbacks, followed by the brief introductions of proposed antimicrobial mechanisms of ε-PL and its recent applications. Finally, we discuss persistent challenges and future perspectives for the commercialization of ε-PL.
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Affiliation(s)
- Liang Wang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Chongyang Zhang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Jianhua Zhang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Zhiming Rao
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Xueming Xu
- School of Food Science and Technology, Jiangnan University, Wuxi, China
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Zhonggui Mao
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Xusheng Chen
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
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Zhang Y, Bai J, Wu C, Wang Y, Ju X, Qi X, Li L, Ji L, Fu J. Efficient production of ε-poly-l-lysine using cassava starch and fish meal by Streptomyces albulus FQC-24. Prep Biochem Biotechnol 2021; 52:525-533. [PMID: 34455924 DOI: 10.1080/10826068.2021.1969577] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
ε-Poly-l-lysine (ε-PL) is used as a natural food preservative which consists of l-lysine units connected. However, due to the expensive culture medium, the production cost of ε-PL remains high. In this study, cheap raw materials cassava starch (CS) and fish meal (FM) were employed by S. albulus FQC-24 for ε-PL production. In the single factor experiment, the maximum ε-PL production reached 0.97 g/L at 60 g/L CS and 15 g/L FM. The results of screening experiments by Plackett-Burman design showed that three main components affecting ε-PL production were CS, FM, and (NH4)2SO4. And the standardized effects of CS, FM, and (NH4)2SO4 were 0.13, -0.22, and -0.2, respectively. The optimum fermentation medium developed by response surface methodology for ε-PL production contained (g/L) CS, 67.56; FM, 14.70 and (NH4)2SO4, 5.41. Under the optimum conditions, the ε-PL production was achieved 1.30 g/L, with 34.02% higher than that before optimization. Moreover, ε-PL productions of batch and fed-batch fermentation in a 7-L fermentor were improved to 2.13 and 17.17 g/L respectively, which increased by 0.64 and 12.2 times compared with the shake flask culture. The results indicated that FM and CS are promising substrates for the efficient production of ε-PL.
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Affiliation(s)
- Yi Zhang
- School of Chemistry and Life Sciences, Suzhou University of Science and Technology, Suzhou, Jiangsu, People's Republic of China
| | - Jing Bai
- School of Chemistry and Life Sciences, Suzhou University of Science and Technology, Suzhou, Jiangsu, People's Republic of China
| | - Chenqi Wu
- School of Chemistry and Life Sciences, Suzhou University of Science and Technology, Suzhou, Jiangsu, People's Republic of China.,College of Food Science and Technology, Suzhou Polytechnic Institute of Agriculture, Suzhou, Jiangsu, People's Republic of China
| | - Yue Wang
- School of Chemistry and Life Sciences, Suzhou University of Science and Technology, Suzhou, Jiangsu, People's Republic of China
| | - Xin Ju
- School of Chemistry and Life Sciences, Suzhou University of Science and Technology, Suzhou, Jiangsu, People's Republic of China
| | - Xin Qi
- School of Chemistry and Life Sciences, Suzhou University of Science and Technology, Suzhou, Jiangsu, People's Republic of China
| | - Liangzhi Li
- School of Chemistry and Life Sciences, Suzhou University of Science and Technology, Suzhou, Jiangsu, People's Republic of China
| | - Lilian Ji
- School of Chemistry and Life Sciences, Suzhou University of Science and Technology, Suzhou, Jiangsu, People's Republic of China
| | - Jiaolong Fu
- School of Chemistry and Life Sciences, Suzhou University of Science and Technology, Suzhou, Jiangsu, People's Republic of China
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Li S, Wang L, Wang N, Cong W. Combining Genome Shuffling with Streptomycin Resistance to Improve Poly-γ-L-diaminobutanoic Acid Production in Bacillus pumilus. BIOTECHNOL BIOPROC E 2021. [DOI: 10.1007/s12257-020-0320-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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20
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Zhou Y, Yan P, Tang L. Self-protection of Streptomyces to ε-poly-l-lysine improves fermentation efficacy. Biochem Eng J 2021. [DOI: 10.1016/j.bej.2021.107935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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21
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Chen S, Huang S, Li Y, Zhou C. Recent Advances in Epsilon-Poly-L-Lysine and L-Lysine-Based Dendrimer Synthesis, Modification, and Biomedical Applications. Front Chem 2021; 9:659304. [PMID: 33869146 PMCID: PMC8044885 DOI: 10.3389/fchem.2021.659304] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 03/02/2021] [Indexed: 12/17/2022] Open
Abstract
With the advantages in biocompatibility, antimicrobial ability, and comparative facile synthesis technology, poly-L-lysine (PLL) has received considerable attention in recent years. Different arrangement forms and structures of the backbone endow lysine-based polymers with versatile applications, especially for ε-poly-L-lysine (EPL) and lysine-based dendrimer (LBD) compounds. This review summarized the advanced development of the synthesis and modification strategies of EPL and LBD, focus on the modification of bio-synthesis and artificial synthesis, respectively. Meanwhile, biomedical fields, where EPL and LBD are mainly utilized, such as agents, adjuvants, or carriers to anti-pathogen or used in tumor or gene therapies, are also introduced. With the deeper of knowledge of pharmacodynamics and pharmacokinetics of the drug system, the design and synthesis of these drugs can be further optimized. Furthermore, the performances of combination with other advanced methodologies and technologies demonstrated that challenges, such as scale production and high expenses, will not hinder the prospective future of lysine-based polymers.
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Affiliation(s)
| | | | - Yan Li
- School of Material Science and Engineering, Tongji University, Shanghai, China
| | - Chuncai Zhou
- School of Material Science and Engineering, Tongji University, Shanghai, China
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Wang J, Gao C, Chen X, Liu L. Expanding the lysine industry: biotechnological production of l-lysine and its derivatives. ADVANCES IN APPLIED MICROBIOLOGY 2021; 115:1-33. [PMID: 34140131 DOI: 10.1016/bs.aambs.2021.02.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
l-lysine is an essential amino acid that contains various functional groups including α-amino, ω-amino, and α-carboxyl groups, exhibiting high reaction potential. The derivatization of these functional groups produces a series of value-added chemicals, such as cadaverine, glutarate, and d-lysine, that are widely applied in the chemical synthesis, cosmetics, food, and pharmaceutical industries. Here, we review recent advances in the biotechnological production of l-lysine and its derivatives and expatiate key technological strategies. Furthermore, we also discuss the existing challenges and potential strategies for more efficient production of these chemicals.
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Affiliation(s)
- Jiaping Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, China; International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, China
| | - Cong Gao
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, China; International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, China
| | - Xiulai Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, China; International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, China
| | - Liming Liu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, China; International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, China.
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Li S, Wang L, Wang N. Enhanced poly-γ-L-diaminobutanoic acid production in Bacillus pumilus by combining genome shuffling with multiple antibiotic-resistance. J Ind Microbiol Biotechnol 2020; 47:1141-1154. [PMID: 32990840 DOI: 10.1007/s10295-020-02315-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 09/21/2020] [Indexed: 11/26/2022]
Abstract
A breeding approach combining genome shuffling with multiple antibiotic-resistance including gentamicin, rifampin and lincomycin, was developed in this research to improve the poly-γ-L-diaminobutanoic acid (γ-PAB) production in Bacillus pumilus LS-1. By this unique strategy, recombinants from the third round of genome shuffling could tolerate higher concentration of compound antibiotics and exhibited higher γ-PAB production as 392.4 mg/L in shake-flask fermentation, tenfold over the parent. In batch fermentation, B. pumilus GS3-M7 could produce γ-PAB as high as 2316.4 mg/L in two days, 5.4-fold higher than the control, which was the highest productivity ever reported. In addition, the optimal pH in B. pumilus for γ-PAB synthesis was decreased after ARTP mutagenesis and protoplast fusion, because the lower pH environment is favorable for accumulation of intracellular ATP. Some key enzymes in GS3-M7 showed higher activities than those in the parent, suggesting a greater flux to TCA circle and DAP pathway, which was a reason for enhanced γ-PAB production.
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Affiliation(s)
- Shu Li
- Marine College, Shandong University, Weihai, 264209, Shandong, China.
| | - Liang Wang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, Jiangsu, China
| | - Nan Wang
- Testing Center, Weihai Food and Drug Administration, Weihai, 264210, China
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Wang L, Li S, Zhao J, Liu Y, Chen X, Tang L, Mao Z. Efficiently activated ε-poly-L-lysine production by multiple antibiotic-resistance mutations and acidic pH shock optimization in Streptomyces albulus. Microbiologyopen 2018; 8:e00728. [PMID: 30298553 PMCID: PMC6528598 DOI: 10.1002/mbo3.728] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 08/09/2018] [Accepted: 08/09/2018] [Indexed: 11/17/2022] Open
Abstract
ε‐Poly‐L‐lysine (ε‐PL) is a food additive produced by Streptomyces and is widely used in many countries. Working with Streptomyces albulus FEEL‐1, we established a method to activate ε‐PL synthesis by successive introduction of multiple antibiotic‐resistance mutations. Sextuple mutant R6 was finally developed by screening for resistance to six antibiotics and produced 4.41 g/L of ε‐PL in a shake flask, which is 2.75‐fold higher than the level produced by the parent strain. In a previous study, we constructed a double‐resistance mutant, SG‐31, with high ε‐PL production of 3.83 g/L and 59.50 g/L in a shake flask and 5‐L bioreactor, respectively. However, we found that R6 did not show obvious advantages in fed‐batch fermentation when compared with SG‐31. For further activation of ε‐PL synthesis ability, we optimized the fermentation process by using an effective acidic pH shock strategy, by which R6 synthetized 70.3 g/L of ε‐PL, 2.79‐fold and 1.18‐fold greater than that synthetized by FEEL‐1 and SG‐31, respectively. To the best of our knowledge, this is the highest reported ε‐PL production to date. This ε‐PL overproduction may be due to the result of R99P and Q856H mutations in ribosomal protein S12 and RNA polymerase, respectively, which may be responsible for the increased transcription of the ε‐poly‐lysine synthetase gene (pls) and key enzyme activities in the Lys synthesis metabolic pathway. Consequently, ε‐PL synthetase activity, intracellular ATP, and Lys concentrations were improved and directly contributed to ε‐PL overproduction. This study combined ribosome engineering, high‐throughput screening, and targeted strategy optimization to accelerate ε‐PL production and probe the fermentation characteristics of hyperyield mutants. The information presented here may be useful for other natural products produced by Streptomyces.
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Affiliation(s)
- Liang Wang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, China
| | - Shu Li
- College of Marine Science, Shandong University (Weihai), Weihai, China
| | - Junjie Zhao
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, China
| | - Yongjuan Liu
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, China
| | - Xusheng Chen
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, China
| | - Lei Tang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, China
| | - Zhonggui Mao
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, China
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