1
|
Gecse G, Labunskaite R, Pedersen M, Kilstrup M, Johanson T. Minimizing acetate formation from overflow metabolism in Escherichia coli: comparison of genetic engineering strategies to improve robustness toward sugar gradients in large-scale fermentation processes. Front Bioeng Biotechnol 2024; 12:1339054. [PMID: 38419731 PMCID: PMC10899681 DOI: 10.3389/fbioe.2024.1339054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 01/15/2024] [Indexed: 03/02/2024] Open
Abstract
Introduction: Escherichia coli, a well characterized workhorse in biotechnology, has been used to produce many recombinant proteins and metabolites, but have a major drawback in its tendency to revert to overflow metabolism. This phenomenon occurs when excess sugar triggers the production of mainly acetate under aerobic conditions, a detrimental by-product that reduces carbon efficiency, increases cell maintenance, and ultimately inhibits growth. Although this can be prevented by controlled feeding of the sugar carbon source to limit its availability, gradients in commercial-scale bioreactors can still induce it in otherwise carbon-limited cells. While the underlying mechanisms have been extensively studied, these have mostly used non-limited cultures. In contrast, industrial production typically employs carbon-limited processes, which results in a substantially different cell physiology. Objective: The objective of this study was to evaluate and compare the efficiency of different metabolic engineering strategies with the aim to reduce overflow metabolism and increase the robustness of an industrial 2'-O-fucosyllactose producing strain under industrially relevant conditions. Methods: Three distinct metabolic engineering strategies were compared: i) alterations to pathways leading to and from acetate, ii) increased flux towards the tricarboxylic acid (TCA) cycle, and iii) reduced glucose uptake rate. The engineered strains were evaluated for growth, acetate formation, and product yield under non-limiting batch conditions, carbon limited fed-batch conditions, and after a glucose pulse in fed-batch mode. Results and Discussion: The findings demonstrated that blockage of the major acetate production pathways by deletion of the pta and poxB genes or increased carbon flux into the TCA cycle by overexpression of the gltA and deletion of the iclR genes, were efficient ways to reduce acetate accumulation. Surprisingly, a reduced glucose uptake rate did not reduce acetate formation despite it having previously been shown as a very effective strategy. Interestingly, overexpression of gltA was the most efficient way to reduce acetate accumulation in non-limited cultures, whereas disruption of the poxB and pta genes was more effective for carbon-limited cultures exposed to a sudden glucose shock. Strains from both strategies showed increased tolerance towards a glucose pulse during carbon-limited growth indicating feasible ways to engineer industrial E. coli strains with enhanced robustness.
Collapse
Affiliation(s)
| | | | | | - Mogens Kilstrup
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs. Lyngby, Denmark
| | | |
Collapse
|
2
|
Wang L, Zhang K, Gao S, Zhang M, Liu T, Cai B, Wang L, Su L, Wu J, Chen S. High-Yield Synthesis of 2'-Fucosyllactose from Glycerol and Glucose in Engineered Escherichia coli. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:15237-15248. [PMID: 37795855 DOI: 10.1021/acs.jafc.3c05015] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/06/2023]
Abstract
2'-Fucosyllactose (2'-FL) is vital for the growth and development of newborns. In this study, we developed a synthesis pathway for 2'-FL in Escherichia coli BL21 (DE3). Then, we optimized the solubility of α-1,2-fucosyltransferase, thereby enhancing the production yield of 2'-FL. Based on this finding, we further enhanced the expression of guanosine inosine kinase Gsk and knocked out the isocitrate lyase regulator gene iclR. This strategy reduced the formation of byproduct acetate during the metabolic process and alleviated carbon source overflow effects in the strain, resulting in further improvement of the yield of 2'-FL. In a 3 L bioreactor, employing fed-batch fermentation with glycerol and glucose as substrates, the engineered strain BWLAI-RSZL exhibited impressive 2'-FL titers of 121.9 and 111.56 g/L, along with productivity levels of 1.57 and 1.31 g/L/h, respectively. The reported 2'-FL titers reached a groundbreaking level, irrespective of the carbon source employed (glycerol or glucose), highlighting the significant potential for large-scale industrial synthesis of 2'-FL.
Collapse
Affiliation(s)
- Luyao Wang
- State Key Laboratory of Food Science and Resources, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Key Laboratory of Industrial Biotechnology Ministry of Education, and International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Kang Zhang
- State Key Laboratory of Food Science and Resources, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Key Laboratory of Industrial Biotechnology Ministry of Education, and International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Shengqi Gao
- State Key Laboratory of Food Science and Resources, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Key Laboratory of Industrial Biotechnology Ministry of Education, and International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Mengwei Zhang
- State Key Laboratory of Food Science and Resources, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Key Laboratory of Industrial Biotechnology Ministry of Education, and International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Tongle Liu
- State Key Laboratory of Food Science and Resources, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Key Laboratory of Industrial Biotechnology Ministry of Education, and International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Bohan Cai
- State Key Laboratory of Food Science and Resources, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Key Laboratory of Industrial Biotechnology Ministry of Education, and International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Lei Wang
- State Key Laboratory of Food Science and Resources, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Key Laboratory of Industrial Biotechnology Ministry of Education, and International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Lingqia Su
- State Key Laboratory of Food Science and Resources, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Key Laboratory of Industrial Biotechnology Ministry of Education, and International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Jing Wu
- State Key Laboratory of Food Science and Resources, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Key Laboratory of Industrial Biotechnology Ministry of Education, and International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Sheng Chen
- State Key Laboratory of Food Science and Resources, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Key Laboratory of Industrial Biotechnology Ministry of Education, and International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| |
Collapse
|
3
|
Liu YP, Tian MY, Yang YD, Li H, Zhao TT, Zhu J, Mou FF, Cui GH, Guo HD, Shao SJ. Schwann cells-derived exosomal miR-21 participates in high glucose regulation of neurite outgrowth. iScience 2022; 25:105141. [PMID: 36204278 PMCID: PMC9529988 DOI: 10.1016/j.isci.2022.105141] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 08/06/2022] [Accepted: 09/09/2022] [Indexed: 11/29/2022] Open
Abstract
As a common complication of diabetes, the pathogenesis of diabetic peripheral neuropathy (DPN) is closely related to high glucose but has not been clarified. Exosomes can mediate crosstalk between Schwann cells (SC) and neurons in the peripheral nerve. Herein, we found that miR-21 in serum exosomes from DPN rats was decreased. SC proliferation was inhibited, cell apoptosis was increased, and the expression of miR-21 in cells and exosomes was downregulated when cultured in high glucose. Increasing miR-21 expression reversed these changes, while knockdown of miR-21 led to the opposite results. When co-cultured with exosomes derived from SC exposed to high glucose, neurite outgrowth was inhibited. On the contrary, neurite outgrowth was accelerated when incubated with exosomes rich in miR-21. We further demonstrated that the SC-derived exosomal miR-21 participates in neurite outgrowth probably through the AKT signaling pathway. Thus, SC-derived exosomal miR-21 contributes to high glucose regulation of neurite outgrowth. The miR-21 was decreased in serum exosomes and sciatic nerve of DPN rats High glucose inhibited SC viability and downregulated the expression of miR-21 Exosomes derived from SC cultured in high glucose inhibited the neurite outgrowth SC-derived exosomes rich in miR-21 accelerated the neurite outgrowth of neuron
Collapse
Affiliation(s)
- Yu-pu Liu
- Department of Anatomy, School of Basic Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
- Department of Orthopaedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases, Shanghai Institute of Traumatology and Orthopaedics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, PR China
| | - Ming-yue Tian
- Department of Anatomy, School of Basic Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Yi-duo Yang
- Department of Anatomy, School of Basic Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Han Li
- Department of Anatomy, School of Basic Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Tian-tian Zhao
- Department of Anatomy, School of Basic Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Jing Zhu
- Department of Anatomy, School of Basic Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Fang-fang Mou
- Department of Anatomy, School of Basic Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Guo-hong Cui
- Department of Neurology, Shanghai No. 9 People’s Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200011, China
- Corresponding author
| | - Hai-dong Guo
- Department of Anatomy, School of Basic Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
- Academy of Integrative Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
- Corresponding author
| | - Shui-jin Shao
- Department of Anatomy, School of Basic Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
- Corresponding author
| |
Collapse
|