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Gu B, Kim DG, Kim DK, Kim M, Kim HU, Oh MK. Heterologous overproduction of oviedomycin by refactoring biosynthetic gene cluster and metabolic engineering of host strain Streptomyces coelicolor. Microb Cell Fact 2023; 22:212. [PMID: 37838667 PMCID: PMC10576301 DOI: 10.1186/s12934-023-02218-8] [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: 07/09/2023] [Accepted: 09/28/2023] [Indexed: 10/16/2023] Open
Abstract
BACKGROUND Oviedomycin is one among several polyketides known for their potential as anticancer agents. The biosynthetic gene cluster (BGC) for oviedomycin is primarily found in Streptomyces antibioticus. However, because this BGC is usually inactive under normal laboratory conditions, it is necessary to employ systematic metabolic engineering methods, such as heterologous expression, refactoring of BGCs, and optimization of precursor biosynthesis, to allow efficient production of these compounds. RESULTS Oviedomycin BGC was captured from the genome of Streptomyces antibioticus by a newly constructed plasmid, pCBA, and conjugated into the heterologous strain, S. coelicolor M1152. To increase the production of oviedomycin, clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) system was utilized in an in vitro setting to refactor the native promoters within the ovm BGC. The target promoters of refactoring were selected based on examination of factors such as transcription levels and metabolite profiling. Furthermore, genome-scale metabolic simulation was applied to find overexpression targets that could enhance the biosynthesis of precursors or cofactors related to oviedomycin production. The combined approach led to a significant increase in oviedomycin production, reaching up to 670 mg/L, which is the highest titer reported to date. This demonstrates the potential of the approach undertaken in this study. CONCLUSIONS The metabolic engineering approach used in this study led to the successful production of a valuable polyketide, oviedomycin, via BGC cloning, promoter refactoring, and gene manipulation of host metabolism aided by genome-scale metabolic simulation. This approach can be also useful for the efficient production of other secondary molecules encoded by 'silent' BGCs.
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Affiliation(s)
- Boncheol Gu
- Department of Chemical & Biological Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Duck Gyun Kim
- Department of Chemical & Biological Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Do-Kyung Kim
- Department of Chemical & Biological Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Minji Kim
- Department of Chemical and Biomolecular Engineering (BK21 four), Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Hyun Uk Kim
- Department of Chemical and Biomolecular Engineering (BK21 four), Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.
| | - Min-Kyu Oh
- Department of Chemical & Biological Engineering, Korea University, Seoul, 02841, Republic of Korea.
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Chen Y, Yang J, Cai C, Shi J, Song Y, Ma J, Ju J. Development of Marker Recycling Systems for Sequential Genetic Manipulation in Marine-Derived Fungi Spiromastix sp. SCSIO F190 and Aspergillus sp. SCSIO SX7S7. J Fungi (Basel) 2023; 9:jof9030302. [PMID: 36983470 PMCID: PMC10059709 DOI: 10.3390/jof9030302] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 02/23/2023] [Accepted: 02/24/2023] [Indexed: 03/03/2023] Open
Abstract
Marine-derived fungi are emerging as prolific workhorses of structurally novel natural products (NPs) with diverse bioactivities. However, the limitation of available selection markers hampers the exploration of cryptic NPs. Recyclable markers are therefore valuable assets in genetic engineering programs for awaking silent SM clusters. Here, both pyrG and amdS-based recyclable marker cassettes were established and successfully applied in marine-derived fungi Aspergillus sp. SCSIO SX7S7 and Spiromastix sp. SCSIO F190, respectively. Using pyrG recyclable marker, a markerless 7S7-∆depH strain with a simplified HPLC background was built by inactivating a polyketide synthase (PKS) gene depH and looping out the pyrG recyclable marker after depH deletion. Meanwhile, an amdS recyclable marker system was also developed to help strains that are difficult to use pyrG marker. By employing the amdS marker, a backbone gene spm11 responsible for one major product of Spiromastix sp. SCSIO F190 was inactivated, and the amdS marker was excised after using, generating a relatively clean F190-∆spm11 strain for further activation of novel NPs. The collection of two different recycle markers will guarantee flexible application in marine-derived fungi with different genetic backgrounds, enabling the exploitation of novel structures in various fungi species with different genome mining strategies.
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Affiliation(s)
- Yingying Chen
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), No. 1119, Haibin Road, Nansha District, Guangzhou 511458, China
| | - Jiafan Yang
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), No. 1119, Haibin Road, Nansha District, Guangzhou 511458, China
- College of Oceanology, University of Chinese Academy of Sciences, Qingdao 266400, China
| | - Cunlei Cai
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), No. 1119, Haibin Road, Nansha District, Guangzhou 511458, China
- College of Oceanology, University of Chinese Academy of Sciences, Qingdao 266400, China
| | - Junjie Shi
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), No. 1119, Haibin Road, Nansha District, Guangzhou 511458, China
- College of Oceanology, University of Chinese Academy of Sciences, Qingdao 266400, China
| | - Yongxiang Song
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), No. 1119, Haibin Road, Nansha District, Guangzhou 511458, China
| | - Junying Ma
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), No. 1119, Haibin Road, Nansha District, Guangzhou 511458, China
- Correspondence: (J.M.); (J.J.); Tel.: +86-20-8902-3028 (J.J.)
| | - Jianhua Ju
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), No. 1119, Haibin Road, Nansha District, Guangzhou 511458, China
- Correspondence: (J.M.); (J.J.); Tel.: +86-20-8902-3028 (J.J.)
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CRISPR/Cas9-Based Genome Editing and Its Application in Aspergillus Species. J Fungi (Basel) 2022; 8:jof8050467. [PMID: 35628723 PMCID: PMC9143064 DOI: 10.3390/jof8050467] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Revised: 04/28/2022] [Accepted: 04/29/2022] [Indexed: 02/04/2023] Open
Abstract
Aspergillus, a genus of filamentous fungi, is extensively distributed in nature and plays crucial roles in the decomposition of organic materials as an important environmental microorganism as well as in the traditional fermentation and food processing industries. Furthermore, due to their strong potential to secrete a large variety of hydrolytic enzymes and other natural products by manipulating gene expression and/or introducing new biosynthetic pathways, several Aspergillus species have been widely exploited as microbial cell factories. In recent years, with the development of next-generation genome sequencing technology and genetic engineering methods, the production and utilization of various homo-/heterologous-proteins and natural products in Aspergillus species have been well studied. As a newly developed genome editing technology, the clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) system has been used to edit and modify genes in Aspergilli. So far, the CRISPR/Cas9-based approach has been widely employed to improve the efficiency of gene modification in the strain type Aspergillus nidulans and other industrially important and pathogenic Aspergillus species, including Aspergillus oryzae, Aspergillus niger, and Aspergillus fumigatus. This review highlights the current development of CRISPR/Cas9-based genome editing technology and its application in basic research and the production of recombination proteins and natural products in the Aspergillus species.
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Exploration and characterization of hypoxia-inducible endogenous promoters in Aspergillus niger. Appl Microbiol Biotechnol 2021; 105:5529-5539. [PMID: 34254155 DOI: 10.1007/s00253-021-11417-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 05/25/2021] [Accepted: 05/29/2021] [Indexed: 12/13/2022]
Abstract
Aspergillus niger is widely used for the efficient production of organic acids and enzyme preparations. However, this organism lacks basic genetic elements for dynamic control, especially inducible promoters that can respond to specific environmental signals. Since these are desirable for better adaptation of fermentation to large-scale industrial production, herein, we have identified the two first hypoxia-inducible promoters in A. niger, PsrbB and PfhbA. Their performance under high or low oxygen conditions was monitored using two reporter proteins, green fluorescent protein (EGFP) and β-glucuronidase (GUS). For comparison, basal expression of the general strong promoter PgpdA was lower than PsrbB but higher than PfhbA. However, under hypoxia, both promoters showed higher expression than under hyperoxia, and these values were also higher than those observed for PgpdA. For PsrbB, strength under hypoxia was ~2-3 times higher than under hyperoxia (for PfhbA, 3-9 times higher) and ~2.5-5 times higher than for PgpdA (for PfhbA, 2-3 times higher). Promoter truncation analysis showed that the PsrbB fragment -1024 to -588 bp is the core region that determines hypoxia response. KEY POINTS: The first identification of two hypoxia-inducible promoters in A. niger is a promising tool for modulation of target genes under hypoxia. Two reporter genes revealed a different activity and responsiveness to hypoxia of PfhbA and PsrbB promoters, which is relevant for the development of dynamic metabolic regulation of A. niger fermentation. PsrbB promoter truncation and bioinformatics analysis is the foundation for further research.
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Sun R, Xu H, Feng Y, Hou X, Zhu T, Che Q, Pfeifer B, Zhang G, Li D. An efficient marker recycling system for sequential gene deletion in a deep sea-derived fungus Acremonium sp. HDN16-126. Synth Syst Biotechnol 2021; 6:127-133. [PMID: 34141909 PMCID: PMC8187431 DOI: 10.1016/j.synbio.2021.05.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 05/11/2021] [Accepted: 05/17/2021] [Indexed: 11/17/2022] Open
Abstract
Acremonium species are prolific producers of therapeutic molecules which include the widely used beta-lactam antibiotic, cephalosporin. In light of their significant medical value, an efficient gene disruption method is required for the physiological and biochemical studies on this genus of fungi. However, the number of selection markers that can be used for gene targeting is limited, which constrain the genetic analysis of multiple functional genes. In this study, we established a uridine auxotrophy based marker recycling system which achieves scarless gene deletion, and allows the use of the same selection marker in successive transformations in a deep sea-derived fungus Acremonium sp. HDN16-126. We identified one homologue of Acremonium chrysogenum pyrG (also as a homologous gene of the yeast URA3) from HDN16-126, designated as pyrG-A1, which can be used as a selection marker on uridine free medium. We then removed pyrG-A1 from HDN16-126 genome via homologous recombination (HR) on MM medium with 5-fluoroortic acid (5-FOA), a chemical that can be converted into a toxin of 5-flurouracil by pyrG-A1 activity, thus generating the HDN16-126-△pyrG mutant strain which showed auxotrophy for uridine but insensitivity to 5-FOA and enabled the use of exogenous pyrG gene as both positive and negative selection marker to achieve the scarless deletion of target DNA fragments. We further applied this marker recycling system to successfully disrupt two target genes pepL (encodes a putative 2OG-Fe (II) dioxygenase) and pepM (encodes a putative aldolase) identified from HDN16-126 genome, which are proposed to be functional genes related to 2-aminoisobutyric acid metabolism in fungi. This work is the first application of uridine auxotrophy based scarless gene deletion method in Acremonium species and shows promising potential in assisting sequential genetic analysis of filamentous fungi.
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Affiliation(s)
- Ruonan Sun
- School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, People's Republic of China
| | - Hengyi Xu
- School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, People's Republic of China
| | - Yanyan Feng
- School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, People's Republic of China
| | - Xuewen Hou
- School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, People's Republic of China
| | - Tianjiao Zhu
- School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, People's Republic of China
| | - Qian Che
- School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, People's Republic of China
| | - Blaine Pfeifer
- Department of Chemical and Biological Engineering, The State University of New York at Buffalo, Buffalo, NY, 14260, United States
| | - Guojian Zhang
- School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, People's Republic of China
- Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, People's Republic of China
- Corresponding author. School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, People's Republic of China.
| | - Dehai Li
- School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, People's Republic of China
- Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, People's Republic of China
- Corresponding author. Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, People's Republic of China.
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Yoshioka I, Kirimura K. Rapid and marker-free gene replacement in citric acid-producing Aspergillus tubingensis (A. niger) WU-2223L by the CRISPR/Cas9 system-based genome editing technique using DNA fragments encoding sgRNAs. J Biosci Bioeng 2021; 131:579-588. [PMID: 33612423 DOI: 10.1016/j.jbiosc.2021.01.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 01/11/2021] [Accepted: 01/30/2021] [Indexed: 01/19/2023]
Abstract
Strains belonging to Aspergillus section Nigri, including Aspergillus niger, are used for industrial production of citric acid from carbohydrates such as molasses and starch. The objective of this study was to construct the genome editing system that could enable rapid and efficient gene replacement in citric acid-producing fungi for genetic breeding. Using the citric acid-hyperproducer A. tubingensis (formerly A. niger) WU-2223L as a model strain, we developed a CRISPR/Cas9 system-based genome editing technique involving co-transformation of Cas9 and the DNA fragment encoding single guide RNA (sgRNA). Using this system, ATP-sulfurylase gene (sC) knock-out strain derived from WU-2223L was generated; the knock-out efficiency was 29 transformants when 5 μg Cas9 was added to 5 × 105 protoplasts. In the gene replacement method based on this system, a DNA fragment encoding sgRNAs that target both the gene of interest and marker gene was used, and replacement of nitrate reductase gene (niaD) using sC gene as a marker gene was attempted. More than 90% of the sC-knock-out transformants exhibited replaced niaD, indicating efficient gene replacement. Moreover, one-step marker rescue of the sC marker gene was accomplished by excising the knock-in donor via intramolecular homologous recombination, enabling marker-free genome editing and drastically shortening the gene replacement period by circumventing the transformation procedure to recover the sC gene. Thus, we succeeded in constructing a CRISPR/Cas9 system-based rapid and marker-free gene replacement system for the citric acid-hyperproducer strain WU-2223L.
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Affiliation(s)
- Isato Yoshioka
- Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan
| | - Kohtaro Kirimura
- Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan.
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