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Nishitani A, Hiramatsu K, Kadooka C, Hiroshima K, Sawada K, Okutsu K, Yoshizaki Y, Takamine K, Goto M, Tamaki H, Futagami T. Overexpression of the DHA1 family, ChlH and ChlK, leads to enhanced dicarboxylic acids production in koji fungi, Aspergillus luchuensis mut. kawachii and Aspergillus oryzae. J Biosci Bioeng 2024; 137:281-289. [PMID: 38331655 DOI: 10.1016/j.jbiosc.2024.01.010] [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: 09/26/2023] [Revised: 01/09/2024] [Accepted: 01/14/2024] [Indexed: 02/10/2024]
Abstract
The white koji fungus Aspergillus luchuensis mut. kawachii secretes substantial amounts of citric acid through the expression of the citric acid exporter CexA, a member of the DHA1 family. In this study, we aimed to characterize 11 CexA homologs (Chl proteins) encoded in the genome of A. luchuensis mut. kawachii to identify novel transporters useful for organic acid production. We constructed overexpression strains of chl genes using a cexA disruptant of the A. luchuensis mut. kawachii as the host strain, which prevented excessive secretion of citric acid into the culture supernatant. Subsequently, we evaluated the effects of overexpression of chl on producing organic acids by analyzing the culture supernatant. All overexpression strains did not exhibit significant citric acid accumulation in the culture supernatant, indicating that Chl proteins are not responsible for citric acid export. Furthermore, the ChlH overexpression strain displayed an accumulation of 2-oxoglutaric and fumaric acids in the culture supernatant, while the ChlK overexpression strain exhibited the accumulation of 2-oxoglutaric, malic and succinic acids. Notably, the ChlH and ChlK overexpression led to a substantial increase in the production of 2-oxoglutaric acid, reaching approximately 25 mM and 50 mM, respectively. Furthermore, ChlH and ChlK overexpression also significantly increased the secretory production of dicarboxylic acids, including 2-oxoglutaric acid, in the yellow koji fungus, Aspergillus oryzae. Our study demonstrates that overexpression of DHA1 family gene results in enhanced secretion of organic acids in koji fungi of the genus Aspergillus.
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Affiliation(s)
- Atsushi Nishitani
- United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima 890-0065, Japan; Center for Advanced Science Research and Promotion, Kagoshima University, Kagoshima 890-0065, Japan
| | - Kentaro Hiramatsu
- Graduate School of Agriculture, Forestry and Fisheries, Kagoshima University, Kagoshima 890-0065, Japan
| | - Chihiro Kadooka
- Department of Biotechnology and Life Sciences, Faculty of Biotechnology and Life Sciences, Sojo University, Kumamoto 860-0082, Japan
| | - Kyoka Hiroshima
- Graduate School of Agriculture, Forestry and Fisheries, Kagoshima University, Kagoshima 890-0065, Japan
| | | | - Kayu Okutsu
- Graduate School of Agriculture, Forestry and Fisheries, Kagoshima University, Kagoshima 890-0065, Japan; Education and Research Center for Fermentation Studies, Faculty of Agriculture, Kagoshima University, Kagoshima 890-0065, Japan
| | - Yumiko Yoshizaki
- United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima 890-0065, Japan; Graduate School of Agriculture, Forestry and Fisheries, Kagoshima University, Kagoshima 890-0065, Japan; Education and Research Center for Fermentation Studies, Faculty of Agriculture, Kagoshima University, Kagoshima 890-0065, Japan
| | - Kazunori Takamine
- United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima 890-0065, Japan; Graduate School of Agriculture, Forestry and Fisheries, Kagoshima University, Kagoshima 890-0065, Japan; Education and Research Center for Fermentation Studies, Faculty of Agriculture, Kagoshima University, Kagoshima 890-0065, Japan
| | - Masatoshi Goto
- United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima 890-0065, Japan; Department of Applied Biochemistry and Food Science, Faculty of Agriculture, Saga University, Saga 840-8502, Japan
| | - Hisanori Tamaki
- United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima 890-0065, Japan; Graduate School of Agriculture, Forestry and Fisheries, Kagoshima University, Kagoshima 890-0065, Japan; Education and Research Center for Fermentation Studies, Faculty of Agriculture, Kagoshima University, Kagoshima 890-0065, Japan
| | - Taiki Futagami
- United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima 890-0065, Japan; Graduate School of Agriculture, Forestry and Fisheries, Kagoshima University, Kagoshima 890-0065, Japan; Education and Research Center for Fermentation Studies, Faculty of Agriculture, Kagoshima University, Kagoshima 890-0065, Japan.
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Deng S, Kim J, Pomraning KR, Gao Y, Evans JE, Hofstad BA, Dai Z, Webb-Robertson BJ, Powell SM, Novikova IV, Munoz N, Kim YM, Swita M, Robles AL, Lemmon T, Duong RD, Nicora C, Burnum-Johnson KE, Magnuson J. Identification of a specific exporter that enables high production of aconitic acid in Aspergillus pseudoterreus. Metab Eng 2023; 80:163-172. [PMID: 37778408 DOI: 10.1016/j.ymben.2023.09.011] [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: 01/31/2023] [Revised: 07/25/2023] [Accepted: 09/18/2023] [Indexed: 10/03/2023]
Abstract
Aconitic acid is an unsaturated tricarboxylic acid that is attractive for its potential use in manufacturing biodegradable and biocompatible polymers, plasticizers, and surfactants. Previously Aspergillus pseudoterreus was engineered as a platform to produce aconitic acid by deleting the cadA (cis-aconitic acid decarboxylase) gene in the itaconic acid biosynthetic pathway. In this study, the aconitic acid transporter gene (aexA) was identified using comparative global discovery proteomics analysis between the wild-type and cadA deletion strains. The protein AexA belongs to the Major Facilitator Superfamily (MFS). Deletion of aexA almost abolished aconitic acid secretion, while its overexpression led to a significant increase in aconitic acid production. Transportation of aconitic acid across the plasma membrane is a key limiting step in its production. In vitro, proteoliposome transport assay further validated AexA's function and substrate specificity. This research provides new approaches to efficiently pinpoint and characterize exporters of fungal organic acids and accelerate metabolic engineering to improve secretion capability and lower the cost of bioproduction.
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Affiliation(s)
- Shuang Deng
- DOE Agile Biofoundry, Emeryville, CA, 94608, USA; Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
| | - Joonhoon Kim
- DOE Agile Biofoundry, Emeryville, CA, 94608, USA; Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
| | - Kyle R Pomraning
- DOE Agile Biofoundry, Emeryville, CA, 94608, USA; Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
| | - Yuqian Gao
- DOE Agile Biofoundry, Emeryville, CA, 94608, USA; Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
| | - James E Evans
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
| | - Beth A Hofstad
- DOE Agile Biofoundry, Emeryville, CA, 94608, USA; Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
| | - Ziyu Dai
- DOE Agile Biofoundry, Emeryville, CA, 94608, USA; Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
| | - Bobbie-Jo Webb-Robertson
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
| | - Samantha M Powell
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
| | - Irina V Novikova
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
| | - Nathalie Munoz
- DOE Agile Biofoundry, Emeryville, CA, 94608, USA; Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
| | - Young-Mo Kim
- DOE Agile Biofoundry, Emeryville, CA, 94608, USA; Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
| | - Marie Swita
- Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
| | - Ana L Robles
- DOE Agile Biofoundry, Emeryville, CA, 94608, USA; Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
| | - Teresa Lemmon
- Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
| | - Rylan D Duong
- Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
| | - Carrie Nicora
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
| | - Kristin E Burnum-Johnson
- DOE Agile Biofoundry, Emeryville, CA, 94608, USA; Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
| | - Jon Magnuson
- DOE Agile Biofoundry, Emeryville, CA, 94608, USA; Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
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