1
|
Li J, Wang Y, Yang K, Wang X, Wang Y, Zhang H, Huang H, Su X, Yao B, Luo H, Qin X. Development of an efficient protein expression system in the thermophilic fungus Myceliophthora thermophila. Microb Cell Fact 2023; 22:236. [PMID: 37974259 PMCID: PMC10652509 DOI: 10.1186/s12934-023-02245-5] [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: 07/07/2023] [Accepted: 11/05/2023] [Indexed: 11/19/2023] Open
Abstract
BACKGROUND Thermophilic fungus Myceliophthora thermophila has been widely used in industrial applications due to its ability to produce various enzymes. However, the lack of an efficient protein expression system has limited its biotechnological applications. RESULTS In this study, using a laccase gene reporting system, we developed an efficient protein expression system in M. thermophila through the selection of strong constitutive promoters, 5'UTRs and signal peptides. The expression of the laccase was confirmed by enzyme activity assays. The results showed that the Mtpdc promoter (Ppdc) was able to drive high-level expression of the target protein in M. thermophila. Manipulation of the 5'UTR also has significant effects on protein expression and secretion. The best 5'UTR (NCA-7d) was identified. The transformant containing the laccase gene under the Mtpdc promoter, NCA-7d 5'UTR and its own signal peptide with the highest laccase activity (1708 U/L) was obtained. In addition, the expression system was stable and could be used for the production of various proteins, including homologous proteins like MtCbh-1, MtGh5-1, MtLPMO9B, and MtEpl1, as well as a glucoamylase from Trichoderma reesei. CONCLUSIONS An efficient protein expression system was established in M. thermophila for the production of various proteins. This study provides a valuable tool for protein production in M. thermophila and expands its potential for biotechnological applications.
Collapse
Affiliation(s)
- Jinyang Li
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 10093, China
| | - Yidi Wang
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 10093, China
| | - Kun Yang
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 10093, China
| | - Xiaolu Wang
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 10093, China
| | - Yuan Wang
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 10093, China
| | - Honglian Zhang
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 10093, China
| | - Huoqing Huang
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 10093, China
| | - Xiaoyun Su
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 10093, China
| | - Bin Yao
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 10093, China
| | - Huiying Luo
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 10093, China.
| | - Xing Qin
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 10093, China.
| |
Collapse
|
2
|
Dissecting key residues of a C4-dicarboxylic acid transporter to accelerate malate export in Myceliophthora. Appl Microbiol Biotechnol 2023; 107:609-622. [PMID: 36542100 DOI: 10.1007/s00253-022-12336-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 12/05/2022] [Accepted: 12/08/2022] [Indexed: 12/24/2022]
Abstract
Efficient transporters are necessary for high concentration and purity of desired products during industrial production. In this study, we explored the mechanism of substrate transport and preference of the C4-dicarboxylic acid transporter AoMAE in the fungus Myceliophthora thermophila, and investigated the roles of 18 critical amino acid residues within this process. Among them, the residue Arg78, forming a hydrogen bond network with Arg23, Phe25, Thr74, Leu81, His82, and Glu94 to stabilize the protein conformation, is irreplaceable for the export function of AoMAE. Furthermore, varying the residue at position 100 resulted in changes to the size and shape of the substrate binding pocket, leading to alterations in transport efficiencies of both malic acid and succinic acid. We found that the mutation T100S increased malate production by 68%. Using these insights, we successfully generated an AoMAE variant with mutation T100S and deubiquitination, exhibiting an 81% increase in the selective export activity of malic acid. Simply introducing this version of AoMAE into M. thermophila wild-type strain increased production of malic acid from 1.22 to 54.88 g/L. These findings increase our understanding of the structure-function relationships of organic acid transporters and may accelerate the process of engineering dicarboxylic acid transporters with high efficiency. KEY POINTS: • This is the first systematical analysis of key residues of a malate transporter in fungi. • Protein engineering of AoMAE led to 81% increase of malate export activity. • Arg78 was essential for the normal function of AoMAE in M. thermophila. • Substitution of Thr100 affected export efficiency and substrate selectivity of AoMAE.
Collapse
|
3
|
Past, Present, and Future Perspectives on Whey as a Promising Feedstock for Bioethanol Production by Yeast. J Fungi (Basel) 2022; 8:jof8040395. [PMID: 35448626 PMCID: PMC9031875 DOI: 10.3390/jof8040395] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 04/02/2022] [Accepted: 04/11/2022] [Indexed: 12/10/2022] Open
Abstract
Concerns about fossil fuel depletion and the environmental effects of greenhouse gas emissions have led to widespread fermentation-based production of bioethanol from corn starch or sugarcane. However, competition for arable land with food production has led to the extensive investigation of lignocellulosic sources and waste products of the food industry as alternative sources of fermentable sugars. In particular, whey, a lactose-rich, inexpensive byproduct of dairy production, is available in stable, high quantities worldwide. This review summarizes strategies and specific factors essential for efficient lactose/whey fermentation to ethanol. In particular, we cover the most commonly used strains and approaches for developing high-performance strains that tolerate fermentation conditions. The relevant genes and regulatory systems controlling lactose utilization and sources of new genes are also discussed in detail. Moreover, this review covers the optimal conditions, various feedstocks that can be coupled with whey substrates, and enzyme supplements for increasing efficiency and yield. In addition to the historical advances in bioethanol production from whey, this review explores the future of yeast-based fermentation of lactose or whey products for beverage or fuel ethanol as a fertile research area for advanced, environmentally friendly uses of industrial waste products.
Collapse
|
4
|
Liu D, Xu Z, Li J, Liu Q, Yuan Q, Guo Y, Ma H, Tian C. Reconstruction and analysis of genome-scale metabolic model for thermophilic fungus Myceliophthora thermophila. Biotechnol Bioeng 2022; 119:1926-1937. [PMID: 35257374 DOI: 10.1002/bit.28080] [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: 11/30/2021] [Revised: 01/24/2022] [Accepted: 03/03/2022] [Indexed: 11/11/2022]
Abstract
Myceliophthora thermophila, a thermophilic fungus that can degrade and utilize all major polysaccharides in plant biomass, has great potential in biotechnological industries. Here, the first manually curated genome-scale metabolic model iDL1450 for M. thermophila was reconstructed using an auto-generating pipeline with thorough manual curation. The model contains 1450 genes, 2592 reactions and 1784 unique metabolites. High accuracy was shown in predictions related to carbon and nitrogen source utilization based on data obtained from Biolog experiments. Besides, metabolism profiles were analyzed using iDL1450 integrated with transcriptomics data of M. thermophila at various growth temperatures. The refined model provides new insights into thermophilic fungi metabolism and sheds light on model-driven strain design to improve biotechnological applications of this thermophilic lignocellulosic fungus. This article is protected by copyright. All rights reserved.
Collapse
Affiliation(s)
- Defei Liu
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.,National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
| | - Zixiang Xu
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China.,National Engineering Laboratory for Industrial Enzymes and Tianjin Engineering Research Center of Biocatalytic Technology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
| | - Jingen Li
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.,National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
| | - Qian Liu
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.,National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
| | - Qianqian Yuan
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China.,Biodesign Center, Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
| | - Yanmei Guo
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.,National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
| | - Hongwu Ma
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China.,Biodesign Center, Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
| | - Chaoguang Tian
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.,National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
| |
Collapse
|