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Numazawa R, Tanaka Y, Nishioka S, Tsuji R, Maeda H, Tanaka M, Takeuchi M, Yamagata Y. Aspergillus oryzae PrtR alters transcription of individual peptidase genes in response to the growth environment. Appl Microbiol Biotechnol 2024; 108:90. [PMID: 38204127 PMCID: PMC10781853 DOI: 10.1007/s00253-023-12833-5] [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: 03/30/2023] [Revised: 09/19/2023] [Accepted: 09/30/2023] [Indexed: 01/12/2024]
Abstract
Aspergillus oryzae PrtR is an ortholog of the transcription factor PrtT, which positively regulates the transcription of extracellular peptidase genes in Aspergillus niger and Aspergillus fumigatus. To identify the genes under the control of PrtR and elucidate its regulatory mechanism in A. oryzae, prtR gene disruption mutants were generated. The control strain clearly showed a halo on media containing skim milk as the nitrogen source, whereas the ΔprtR strain formed a smaller halo. Measurement of acid peptidase activity revealed that approximately 84% of acidic endopeptidase and 86% of carboxypeptidase activities are positively regulated by PrtR. As the transcription of the prtR gene varied depending on culture conditions, especially with or without a protein substrate, it was considered that its transcription would be regulated in response to a nitrogen source. In addition, contrary to previous expectations, PrtR was found to act both in promoting and repressing the transcription of extracellular peptidase genes. The mode of regulation varied from gene to gene. Some genes were regulated in the same manner in both liquid and solid cultures, whereas others were regulated in different ways depending on the culture conditions. Furthermore, PrtR has been suggested to regulate the transcription of peptidase genes that are closely associated with other transcription factors. KEY POINTS: • Almost all peptidase genes in Aspergillus oryzae are positively regulated by PrtR • However, several genes are regulated negatively by PrtR • PrtR optimizes transcription of peptidase genes in response to culture conditions.
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Affiliation(s)
- Rika Numazawa
- Department of Applied Biological Science, United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-Cho, Fuchu, Tokyo, 1838509, Japan
| | - Yukako Tanaka
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-Cho, Fuchu, Tokyo, 1838509, Japan
| | - Sawako Nishioka
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-Cho, Fuchu, Tokyo, 1838509, Japan
| | - Ryotaro Tsuji
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-Cho, Fuchu, Tokyo, 1838509, Japan
| | - Hiroshi Maeda
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-Cho, Fuchu, Tokyo, 1838509, Japan
| | - Mizuki Tanaka
- Department of Applied Biological Science, United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-Cho, Fuchu, Tokyo, 1838509, Japan
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-Cho, Fuchu, Tokyo, 1838509, Japan
| | - Michio Takeuchi
- Department of Applied Biological Science, United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-Cho, Fuchu, Tokyo, 1838509, Japan
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-Cho, Fuchu, Tokyo, 1838509, Japan
| | - Youhei Yamagata
- Department of Applied Biological Science, United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-Cho, Fuchu, Tokyo, 1838509, Japan.
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-Cho, Fuchu, Tokyo, 1838509, Japan.
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Tanaka M. Transcriptional and post-transcriptional regulation of genes encoding secretory proteins in Aspergillus oryzae. Biosci Biotechnol Biochem 2024; 88:381-388. [PMID: 38211972 DOI: 10.1093/bbb/zbae004] [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: 11/23/2023] [Accepted: 01/01/2024] [Indexed: 01/13/2024]
Abstract
Aspergillus oryzae, also known as the yellow koji mold, produces various hydrolytic enzymes that are widely used in different industries. Its high capacity to produce secretory proteins makes this filamentous fungus a suitable host for heterologous protein production. Amylolytic gene promoter is widely used to express heterologous genes in A. oryzae. The expression of this promoter is strictly regulated by several transcription factors, whose activation involves various factors. Furthermore, the expression levels of amylolytic and heterologous genes are post-transcriptionally regulated by mRNA degradation mechanisms in response to aberrant transcriptional termination or endoplasmic reticulum stress. This review discusses the transcriptional and post-transcriptional regulatory mechanisms controlling the expression of genes encoding secretory proteins in A. oryzae.
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Affiliation(s)
- Mizuki Tanaka
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, Japan
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Chen X, Moran Torres JP, Wösten HAB. The role of the Flb protein family in the life cycle of Aspergillus niger. Antonie Van Leeuwenhoek 2024; 117:58. [PMID: 38502333 PMCID: PMC10950988 DOI: 10.1007/s10482-024-01957-x] [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: 01/16/2024] [Accepted: 03/04/2024] [Indexed: 03/21/2024]
Abstract
Genes flbA-E are involved in sporulation and vegetative growth in Aspergillus nidulans. Inactivation of either of these genes results in a fluffy phenotype with delayed or even abolished sporulation. Previously, a non-sporulating phenotype was obtained by inactivating flbA in Aspergillus niger, which was accompanied by lysis, thinner cell walls, and an increased secretome complexity. Here, we further studied the role of the flb genes of A. niger. Strains ΔflbA, ΔflbB and ΔflbE showed increased biomass formation, while inactivation of flbA-D reduced, or even abolished, formation of conidia. Strain ΔflbA was more sensitive to H2O2, DTT, and the cell wall integrity stress compounds SDS and Congo Red (CR). Also, ΔflbC was more sensitive to SDS, while ΔflbB, ΔflbD, and ΔflbE were more sensitive to CR. On the other hand, inactivation of flbE increased resistance to H2O2. Enzyme secretion was impacted when the Δflb strains were grown on xylose. Strain ΔflbE showed reduced xylanase, cellulase and amylase secretion. On the other hand, amylase secretion at the periphery of the ΔflbA colony was reduced but not in its center, while secretion of this enzyme was increased in the center of the ΔflbB colony but not at its periphery. Inactivation of flbC and flbD also impacted zonal cellulase and amylase activity. Together, the Flb protein family of A. niger function in biomass formation, sporulation, stress response, and protein secretion.
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Affiliation(s)
- Xiaoyi Chen
- Microbiology, Department of Biology, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Juan P Moran Torres
- Microbiology, Department of Biology, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Han A B Wösten
- Microbiology, Department of Biology, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands.
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Matsuzawa T. Plant polysaccharide degradation-related enzymes in Aspergillus oryzae. Biosci Biotechnol Biochem 2024; 88:276-282. [PMID: 38066701 DOI: 10.1093/bbb/zbad177] [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: 10/25/2023] [Accepted: 12/06/2023] [Indexed: 02/22/2024]
Abstract
Plants synthesize large amounts of stored and structural polysaccharides. Aspergillus oryzae is used in traditional Japanese fermentation and produces many types of plant polysaccharide degradation-related enzymes. The carbohydrate-active enzymes of A. oryzae are important in the fermentation process and biotechnological applications. Because plant polysaccharides have a complex structure, cooperative and synergistic actions of enzymes are crucial for the degradation of plant polysaccharides. For example, the cooperative action of isoprimeverose-producing oligoxyloglucan hydrolase, β-galactosidase, and α-xylosidase is important for the degradation of xyloglucan, and A. oryzae coordinates these enzymes at the expression level. In this review, I focus on the plant polysaccharide degradation-related enzymes identified in A. oryzae.
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Affiliation(s)
- Tomohiko Matsuzawa
- Department of Applied Biological Science, Faculty of Agriculture, Kagawa University, Miki, Kagawa, Japan
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Chen J, Tonouchi A. Copper ion (Cu2+) is involved in the transcription of the tyrosinase-encoding melB gene of Aspergillus oryzae in solid-state culture. Biosci Biotechnol Biochem 2024; 88:220-224. [PMID: 37977852 DOI: 10.1093/bbb/zbad162] [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: 09/12/2023] [Accepted: 11/13/2023] [Indexed: 11/19/2023]
Abstract
In Aspergillus oryzae, the tyrosinase-encoding gene melB causes undesirable browning of sake and sake lees. This gene is known to be expressed specifically in solid-state culture; however, its expression mechanisms remain unknown. Here, we evaluated the possible factors affecting the transcription of melB and found that the copper ion (Cu2+) significantly enhanced the transcription level of melB in solid-state culture.
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Affiliation(s)
- Jun Chen
- The United Graduate School of Agricultural Sciences, Iwate University, Morioka, Iwate, Japan
| | - Akio Tonouchi
- The United Graduate School of Agricultural Sciences, Iwate University, Morioka, Iwate, Japan
- Faculty of Agriculture and Life Science, Hirosaki University, Hirosaki, Aomori, Japan
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Nishitani A, Hiramatsu K, Kadooka C, Mori K, Okutsu K, Yoshizaki Y, Takamine K, Tashiro K, Goto M, Tamaki H, Futagami T. Expression of heterochromatin protein 1 affects citric acid production in Aspergillus luchuensis mut. kawachii. J Biosci Bioeng 2023; 136:443-451. [PMID: 37775438 DOI: 10.1016/j.jbiosc.2023.09.004] [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: 06/11/2023] [Revised: 08/17/2023] [Accepted: 09/07/2023] [Indexed: 10/01/2023]
Abstract
A putative methyltransferase, LaeA, controls citric acid production through epigenetic regulation of the citrate exporter gene, cexA, in the white koji fungus Aspergillus luchuensis mut. kawachii. In this study, we investigated the role of another epigenetic regulator, heterochromatin protein 1, HepA, in citric acid production. The ΔhepA strain exhibited reduced citric acid production in liquid culture, although to a lesser extent compared to the ΔlaeA strain. In addition, the ΔlaeA ΔhepA strain showed citric acid production similar to the ΔlaeA strain, indicating that HepA plays a role in citric acid production, albeit with a less-significant regulatory effect than LaeA. RNA-seq analysis revealed that the transcriptomic profiles of the ΔhepA and ΔlaeA strains were similar, and the expression level of cexA was reduced in both strains. These findings suggest that the genes regulated by HepA are similar to those regulated by LaeA in A. luchuensis mut. kawachii. However, the reductions in citric acid production and cexA expression observed in the disruptants were mitigated in rice koji, a solid-state culture. Thus, the mechanism by which citric acid production is regulated differs between liquid and solid cultivation. Further investigation is thus needed to understand the regulatory mechanism in koji.
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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
| | - Kazuki Mori
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 819-0395, 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
| | - Kosuke Tashiro
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 819-0395, 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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Liu L, Lyu X, Pan Z, Wang Q, Mu W, Benny U, Rollins JA, Pan H. The C2H2 Transcription Factor SsZFH1 Regulates the Size, Number, and Development of Apothecia in Sclerotinia sclerotiorum. PHYTOPATHOLOGY 2022; 112:1476-1485. [PMID: 35021860 DOI: 10.1094/phyto-09-21-0378-r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Sclerotinia sclerotiorum is a notorious phytopathogenic Ascomycota fungus with a host range of >600 plant species worldwide. This homothallic Leotiomycetes species reproduces sexually through a multicellular apothecium that produces and releases ascospores. These ascospores serve as the primary inoculum source for disease initiation in the majority of S. sclerotiorum disease cycles. The regulation of apothecium development for this pathogen and other apothecium-producing fungi remains largely unknown. Here, we report that a C2H2 transcription factor, SsZFH1 (zinc finger homologous protein), is necessary for the proper development and maturation of sclerotia and apothecia in S. sclerotiorum and is required for the normal growth rate of hyphae. Furthermore, ΔSszfh1 strains exhibit decreased H2O2 accumulation in hyphae, increased melanin deposition, and enhanced tolerance to H2O2 in the process of vegetative growth and sclerotia formation. Infection assays on common bean leaves, with thin cuticles, and soybean and tomato leaves, with thick cuticles, suggest that the deletion of Sszfh1 slows the mycelial growth rate, which in turn affects the expansion of leaf lesions. Collectively, our results provide novel insights into a major fungal factor mediating maturation of apothecia with additional effects on hyphae and sclerotia development.
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Affiliation(s)
- Ling Liu
- College of Plant Sciences, Jilin University, Changchun 130062, China
- College of Plant Protection, Jilin Agricultural University, Changchun 130118, China
| | - Xingming Lyu
- College of Plant Sciences, Jilin University, Changchun 130062, China
| | - Zequn Pan
- College of Plant Protection, Jilin Agricultural University, Changchun 130118, China
| | - Qiaochu Wang
- College of Plant Sciences, Jilin University, Changchun 130062, China
| | - Wenhui Mu
- College of Plant Sciences, Jilin University, Changchun 130062, China
| | - Ulla Benny
- Department of Plant Pathology, University of Florida, Gainesville, FL 32611, U.S.A
| | - Jeffrey A Rollins
- Department of Plant Pathology, University of Florida, Gainesville, FL 32611, U.S.A
| | - Hongyu Pan
- College of Plant Sciences, Jilin University, Changchun 130062, China
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Tanaka M, Gomi K. Induction and Repression of Hydrolase Genes in Aspergillus oryzae. Front Microbiol 2021; 12:677603. [PMID: 34108952 PMCID: PMC8180590 DOI: 10.3389/fmicb.2021.677603] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 04/26/2021] [Indexed: 11/13/2022] Open
Abstract
The filamentous fungus Aspergillus oryzae, also known as yellow koji mold, produces high levels of hydrolases such as amylolytic and proteolytic enzymes. This property of producing large amounts of hydrolases is one of the reasons why A. oryzae has been used in the production of traditional Japanese fermented foods and beverages. A wide variety of hydrolases produced by A. oryzae have been used in the food industry. The expression of hydrolase genes is induced by the presence of certain substrates, and various transcription factors that regulate such expression have been identified. In contrast, in the presence of glucose, the expression of the glycosyl hydrolase gene is generally repressed by carbon catabolite repression (CCR), which is mediated by the transcription factor CreA and ubiquitination/deubiquitination factors. In this review, we present the current knowledge on the regulation of hydrolase gene expression, including CCR, in A. oryzae.
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Affiliation(s)
- Mizuki Tanaka
- Biomolecular Engineering Laboratory, School of Food and Nutritional Science, University of Shizuoka, Shizuoka, Japan
| | - Katsuya Gomi
- Laboratory of Fermentation Microbiology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
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Jin FJ, Hu S, Wang BT, Jin L. Advances in Genetic Engineering Technology and Its Application in the Industrial Fungus Aspergillus oryzae. Front Microbiol 2021; 12:644404. [PMID: 33708187 PMCID: PMC7940364 DOI: 10.3389/fmicb.2021.644404] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 02/05/2021] [Indexed: 12/19/2022] Open
Abstract
The filamentous fungus Aspergillus oryzae is an important strain in the traditional fermentation and food processing industries and is often used in the production of soy sauce, soybean paste, and liquor-making. In addition, A. oryzae has a strong capacity to secrete large amounts of hydrolytic enzymes; therefore, it has also been used in the enzyme industry as a cell factory for the production of numerous native and heterologous enzymes. However, the production and secretion of foreign proteins by A. oryzae are often limited by numerous bottlenecks that occur during transcription, translation, protein folding, translocation, degradation, transport, secretion, etc. The existence of these problems makes it difficult to achieve the desired target in the production of foreign proteins by A. oryzae. In recent years, with the decipherment of the whole genome sequence, basic research and genetic engineering technologies related to the production and utilization of A. oryzae have been well developed, such as the improvement of homologous recombination efficiency, application of selectable marker genes, development of large chromosome deletion technology, utilization of hyphal fusion techniques, and application of CRISPR/Cas9 genome editing systems. The development and establishment of these genetic engineering technologies provided a great deal of technical support for the industrial production and application of A. oryzae. This paper reviews the advances in basic research and genetic engineering technologies of the fermentation strain A. oryzae mentioned above to open up more effective ways and research space for the breeding of A. oryzae production strains in the future.
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Affiliation(s)
- Feng-Jie Jin
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Nanjing, China
| | - Shuang Hu
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Nanjing, China
| | - Bao-Teng Wang
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Nanjing, China
| | - Long Jin
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Nanjing, China
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Daranagama ND, Suzuki Y, Shida Y, Ogasawara W. Involvement of Xyr1 and Are1 for Trichodermapepsin Gene Expression in Response to Cellulose and Galactose in Trichoderma reesei. Curr Microbiol 2020; 77:1506-1517. [DOI: 10.1007/s00284-020-01955-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 03/18/2020] [Indexed: 10/24/2022]
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Yasui M, Oda K, Masuo S, Hosoda S, Katayama T, Maruyama JI, Takaya N, Takeshita N. Invasive growth of Aspergillus oryzae in rice koji and increase of nuclear number. Fungal Biol Biotechnol 2020; 7:8. [PMID: 32518660 PMCID: PMC7275602 DOI: 10.1186/s40694-020-00099-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 05/23/2020] [Indexed: 01/02/2023] Open
Abstract
Background 'Rice koji' is a solid culture of Aspergillus oryzae on steamed rice grains. Multiple parallel fermentation, wherein saccharification of rice by A. oryzae and alcohol fermentation by the budding yeast occur simultaneously, leads to the formation of a variety of ingredients of Japanese sake. In sake brewing, the degree of mycelial invasive growth into the steamed rice, called 'haze-komi', highly correlates with the digestibility and quality of rice koji, since the hyphae growing into the rice secrete amylases and digest starch. Results In this study, we investigated mycelial distribution of GFP-tagged A. oryzae in rice koji made with different types of rice, such as sake rice and eating rice, with 50 or 90% polishing rate to remove abundant proteins and lipids near the surface. In addition, we compared transcriptomes of A. oryzae in the different types of rice koji. Finally, we found that A. oryzae increases the nuclear number and hyphal width in the course of 1-3 days cultivation. Conclusions Our imaging analyses indicate that A. oryzae hyphae grew more deeply into 50% polished rice than 90% polished rice. The increases of nuclear number may be a selectively acquired characteristic for the high secretory capacity during the long history of cultivation of this species.
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Affiliation(s)
- Mizuki Yasui
- Microbiology Research Center for Sustainability (MiCS), Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Ken Oda
- National Research Institute of Brewing, 3-7-1 Kagamiyama, Higashi-hiroshima, Hiroshima, 739-0046 Japan
| | - Shunsuke Masuo
- Microbiology Research Center for Sustainability (MiCS), Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Shuji Hosoda
- Microbiology Research Center for Sustainability (MiCS), Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Takuya Katayama
- Department of Biotechnology, Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo, Japan
| | - Jun-Ichi Maruyama
- Department of Biotechnology, Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo, Japan
| | - Naoki Takaya
- Microbiology Research Center for Sustainability (MiCS), Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Norio Takeshita
- Microbiology Research Center for Sustainability (MiCS), Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
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Wang BT, Hu S, Yu XY, Jin L, Zhu YJ, Jin FJ. Studies of Cellulose and Starch Utilization and the Regulatory Mechanisms of Related Enzymes in Fungi. Polymers (Basel) 2020; 12:polym12030530. [PMID: 32121667 PMCID: PMC7182937 DOI: 10.3390/polym12030530] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 02/14/2020] [Accepted: 02/16/2020] [Indexed: 12/24/2022] Open
Abstract
Polysaccharides are biopolymers made up of a large number of monosaccharides joined together by glycosidic bonds. Polysaccharides are widely distributed in nature: Some, such as peptidoglycan and cellulose, are the components that make up the cell walls of bacteria and plants, and some, such as starch and glycogen, are used as carbohydrate storage in plants and animals. Fungi exist in a variety of natural environments and can exploit a wide range of carbon sources. They play a crucial role in the global carbon cycle because of their ability to break down plant biomass, which is composed primarily of cell wall polysaccharides, including cellulose, hemicellulose, and pectin. Fungi produce a variety of enzymes that in combination degrade cell wall polysaccharides into different monosaccharides. Starch, the main component of grain, is also a polysaccharide that can be broken down into monosaccharides by fungi. These monosaccharides can be used for energy or as precursors for the biosynthesis of biomolecules through a series of enzymatic reactions. Industrial fermentation by microbes has been widely used to produce traditional foods, beverages, and biofuels from starch and to a lesser extent plant biomass. This review focuses on the degradation and utilization of plant homopolysaccharides, cellulose and starch; summarizes the activities of the enzymes involved and the regulation of the induction of the enzymes in well-studied filamentous fungi.
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Gomi K. Regulatory mechanisms for amylolytic gene expression in the koji mold Aspergillus oryzae. Biosci Biotechnol Biochem 2019; 83:1385-1401. [PMID: 31159661 DOI: 10.1080/09168451.2019.1625265] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The koji mold Aspergillus oryzae has been used in traditional Japanese food and beverage fermentation for over a thousand years. Amylolytic enzymes are important in sake fermentation, wherein production is induced by starch or malto-oligosaccharides. This inducible production requires at least two transcription activators, AmyR and MalR. Among amylolytic enzymes, glucoamylase GlaB is produced exclusively in solid-state culture and plays a critical role in sake fermentation owing to its contribution to glucose generation from starch. A recent study demonstrated that glaB gene expression is regulated by a novel transcription factor, FlbC, in addition to AmyR in solid-state culture. Amylolytic enzyme production is generally repressed by glucose due to carbon catabolite repression (CCR), which is mediated by the transcription factor CreA. Modifying CCR machinery, including CreA, can improve amylolytic enzyme production. This review focuses on the role of transcription factors in regulating A. oryzae amylolytic gene expression.
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Affiliation(s)
- Katsuya Gomi
- a Laboratory of Fermentation Microbiology, Graduate School of Agricultural Science , Tohoku University , Sendai , Japan
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A unique Zn(II) 2-Cys 6-type protein, KpeA, is involved in secondary metabolism and conidiation in Aspergillus oryzae. Fungal Genet Biol 2019; 127:35-44. [PMID: 30790620 DOI: 10.1016/j.fgb.2019.02.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 01/31/2019] [Accepted: 02/10/2019] [Indexed: 12/11/2022]
Abstract
Aspergillus oryzae is an important microorganism in the bio- and food industries; therefore, understanding the mechanism underlying its secondary metabolism regulation is important for ensuring its safe use. Here, we screened a novel Zn(II)2-Cys6-type protein-encoding gene, AO090003001186, designated as kpeA (kojic acid production enhancement A), from an A. oryzae disruption mutant library of transcriptional regulators. kpeA is highly conserved among filamentous fungi and encodes a protein with Zn(II)2-Cys6 motif located in the middle of the sequence. Phylogenetic analysis revealed that KpeA was classified into a distal group compared to other fungal Zn(II)2-Cys6-type transcriptional regulators. A Cys to Ala substitution mutant of KpeA showed identical phenotype to the kpeA disruption strain, confirming that KpeA is novel type Zn(II)2-Cys6 binding protein. Colonies of the kpeA disruption strain (ΔkpeA) had longer aerial hyphae and showed decreased conidia production. Microscopic analysis suggested that the reduced vesicle size and conidial head formation in ΔkpeA strain account for the decreased conidia production. Transcriptional levels of brlA and downstream abaA and wetA were decreased in ΔkpeA strain. Moreover, ΔkpeA strain produced 6-fold more kojic acid than the control strains, and the expression of kojR and kojA was increased in ΔkpeA strain. Therefore, KpeA is a novel Zn(II)2-Cys6-type protein likely involved in conidiation and kojic acid production at the transcriptional level.
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15
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Zhong Y, Lu X, Xing L, Ho SWA, Kwan HS. Genomic and transcriptomic comparison of Aspergillus oryzae strains: a case study in soy sauce koji fermentation. J Ind Microbiol Biotechnol 2018; 45:839-853. [PMID: 29978373 PMCID: PMC6105210 DOI: 10.1007/s10295-018-2059-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 06/18/2018] [Indexed: 12/19/2022]
Abstract
The filamentous fungus Aspergillus oryzae is used in soy sauce koji making due to its high productivity of hydrolytic enzymes. In this study, we compared the genomes and transcriptomes of an industrial strain RD2 and a strain with decreased fermentation performance TS2, aiming to explain their phenotypic differences at the molecular level. Under the regulation of conidiation and fermentation conditions, the enhanced hydrolytic enzyme production and flavor precursor formation in RD2 described a complete expression profile necessary to maintain desirable fermentation performance. By contrast, central carbon metabolism was up-regulated in TS2 for fast growth, suggesting a conflicting relationship between mycelium growth and fermentation performance. Accumulation of mutations also lowered the fermentation performance of TS2. Our study has deepened the understanding of the metabolism and related regulatory mechanisms in desirable koji fermentation. A list of potential molecular markers identified here could facilitate targeted strain maintenance and improvement for better koji fermentation.
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Affiliation(s)
- Yiyi Zhong
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR, China
| | - Xi Lu
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR, China
| | - Lei Xing
- Food Research Centre, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR, China
| | - Shiu Woon Allen Ho
- Lee Kum Kee International Holdings Limited, Taipo, NT, Hong Kong SAR, China
| | - Hoi Shan Kwan
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR, China.
- Food Research Centre, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR, China.
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16
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Miura D, Sugiyama K, Ito A, Ohba-Tanaka A, Tanaka M, Shintani T, Gomi K. The PDR-type ABC transporters AtrA and AtrG are involved in azole drug resistance in Aspergillus oryzae. Biosci Biotechnol Biochem 2018; 82:1840-1848. [PMID: 30011258 DOI: 10.1080/09168451.2018.1497941] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
For strain improvement of Aspergillus oryzae, development of the transformation system is essential, wherein dominant selectable markers, including drug-resistant genes, are available. However, A. oryzae generally has a relatively high resistance to many antifungal drugs effective against yeasts and other filamentous fungi. In the course of the study, while investigating azole drug resistance in A. oryzae, we isolated a spontaneous mutant that exhibited high resistance to azole fungicides and found that pleiotropic drug resistance (PDR)-type ATP-binding cassette (ABC) transporter genes were upregulated in the mutant; their overexpression in the wild-type strain increased azole drug resistance. While deletion of the gene designated atrG resulted in increased azole susceptibility, double deletion of atrG and another gene (atrA) resulted in further azole hypersensitivity. Overall, these results indicate that the ABC transporters AtrA and AtrG are involved in azole drug resistance in A. oryzae.
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Affiliation(s)
- Daisuke Miura
- a Laboratory of Bioindustrial Genomics, Graduate School of Agricultural Science , Tohoku University , Sendai , Japan
| | - Kohei Sugiyama
- a Laboratory of Bioindustrial Genomics, Graduate School of Agricultural Science , Tohoku University , Sendai , Japan
| | - Atsushi Ito
- a Laboratory of Bioindustrial Genomics, Graduate School of Agricultural Science , Tohoku University , Sendai , Japan
| | - Ayumi Ohba-Tanaka
- a Laboratory of Bioindustrial Genomics, Graduate School of Agricultural Science , Tohoku University , Sendai , Japan
| | - Mizuki Tanaka
- a Laboratory of Bioindustrial Genomics, Graduate School of Agricultural Science , Tohoku University , Sendai , Japan
| | - Takahiro Shintani
- a Laboratory of Bioindustrial Genomics, Graduate School of Agricultural Science , Tohoku University , Sendai , Japan
| | - Katsuya Gomi
- a Laboratory of Bioindustrial Genomics, Graduate School of Agricultural Science , Tohoku University , Sendai , Japan.,b Biomolecular Engineering Laboratory, School of Food and Nutritional Science , University of Shizuoka , Shizuoka , Japan
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17
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Ichinose S, Tanaka M, Shintani T, Gomi K. Increased production of biomass-degrading enzymes by double deletion of creA and creB genes involved in carbon catabolite repression in Aspergillus oryzae. J Biosci Bioeng 2018; 125:141-147. [DOI: 10.1016/j.jbiosc.2017.08.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2017] [Revised: 08/11/2017] [Accepted: 08/29/2017] [Indexed: 10/18/2022]
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18
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Yokota JI, Shiro D, Tanaka M, Onozaki Y, Mizutani O, Kakizono D, Ichinose S, Shintani T, Gomi K, Shintani T. Cellular responses to the expression of unstable secretory proteins in the filamentous fungus Aspergillus oryzae. Appl Microbiol Biotechnol 2017; 101:2437-2446. [PMID: 28064367 DOI: 10.1007/s00253-016-8086-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 12/15/2016] [Accepted: 12/21/2016] [Indexed: 12/20/2022]
Abstract
Filamentous fungi are often used as cell factories for recombinant protein production because of their ability to secrete large quantities of hydrolytic enzymes. However, even using strong transcriptional promoters, yields of nonfungal proteins are generally much lower than those of fungal proteins. Recent analyses revealed that expression of certain nonfungal secretory proteins induced the unfolded protein response (UPR), suggesting that they are recognized as proteins with folding defects in filamentous fungi. More recently, however, even highly expressed endogenous secretory proteins were found to evoke the UPR. These findings raise the question of whether the unfolded or misfolded state of proteins is selectively recognized by quality control mechanisms in filamentous fungi. In this study, a fungal secretory protein (1,2-α-D-mannosidase; MsdS) with a mutation that decreases its thermostability was expressed at different levels in Aspergillus oryzae. We found that, at moderate expression levels, wild-type MsdS was secreted to the medium, while the mutant was not. In the strain with a deletion for the hrdA gene, which is involved in the endoplasmic reticulum-associated degradation pathway, mutant MsdS had specifically increased levels in the intracellular fraction but was not secreted. When overexpressed, the mutant protein was secreted to the medium to a similar extent as the wild-type protein; however, the mutant underwent hyperglycosylation and induced the UPR. Deletion of α-amylase (the most abundant secretory protein in A. oryzae) alleviated the UPR induction by mutant MsdS overexpression. These findings suggest that misfolded MsdS and unfolded species of α-amylase might act synergistically for UPR induction.
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Affiliation(s)
- Jun-Ichi Yokota
- Department of Bioindustrial Informatics and Genomics, Graduate School of Agricultural Science, Tohoku University, Sendai, 981-8555, Japan
| | - Daisuke Shiro
- Department of Bioindustrial Informatics and Genomics, Graduate School of Agricultural Science, Tohoku University, Sendai, 981-8555, Japan
| | - Mizuki Tanaka
- Department of Bioindustrial Informatics and Genomics, Graduate School of Agricultural Science, Tohoku University, Sendai, 981-8555, Japan
| | - Yasumichi Onozaki
- Department of Bioindustrial Informatics and Genomics, Graduate School of Agricultural Science, Tohoku University, Sendai, 981-8555, Japan
| | - Osamu Mizutani
- National Research Institute of Brewing, Higashi-Hiroshima, 739-0046, Japan
| | - Dararat Kakizono
- National Research Institute of Brewing, Higashi-Hiroshima, 739-0046, Japan
| | - Sakurako Ichinose
- Department of Bioindustrial Informatics and Genomics, Graduate School of Agricultural Science, Tohoku University, Sendai, 981-8555, Japan
| | - Tomoko Shintani
- Department of Bioindustrial Informatics and Genomics, Graduate School of Agricultural Science, Tohoku University, Sendai, 981-8555, Japan
| | - Katsuya Gomi
- Department of Bioindustrial Informatics and Genomics, Graduate School of Agricultural Science, Tohoku University, Sendai, 981-8555, Japan
| | - Takahiro Shintani
- Department of Bioindustrial Informatics and Genomics, Graduate School of Agricultural Science, Tohoku University, Sendai, 981-8555, Japan.
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GlnR and PhoP Directly Regulate the Transcription of Genes Encoding Starch-Degrading, Amylolytic Enzymes in Saccharopolyspora erythraea. Appl Environ Microbiol 2016; 82:6819-6830. [PMID: 27637875 PMCID: PMC5103082 DOI: 10.1128/aem.02117-16] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2016] [Accepted: 09/07/2016] [Indexed: 11/20/2022] Open
Abstract
Starch-degrading enzymes hydrolyze starch- and starch-derived oligosaccharides to yield glucose. We investigated the transcriptional regulation of genes encoding starch-degrading enzymes in the industrial actinobacterium Saccharopolyspora erythraea We observed that most genes encoding amylolytic enzymes (one α-amylase, one glucoamylase, and four α-glucosidases) were regulated by GlnR and PhoP, which are global regulators of nitrogen and phosphate metabolism, respectively. Electrophoretic mobility shift assays and reverse transcription-PCR (RT-PCR) analyses demonstrated that GlnR and PhoP directly interact with their promoter regions and collaboratively or competitively activate their transcription. Deletion of glnR caused poor growth on starch, maltodextrin, and maltose, whereas overexpression of glnR and phoP increased the total activity of α-glucosidase, resulting in enhanced carbohydrate utilization. Additionally, transcript levels of amylolytic genes and total glucosidase activity were induced in response to nitrogen and phosphate limitation. Furthermore, regulatory effects of GlnR and PhoP on starch-degrading enzymes were conserved in Streptomyces coelicolor A3(2). These results demonstrate that GlnR and PhoP are involved in polysaccharide degradation by mediating the interplay among carbon, nitrogen, and phosphate metabolism in response to cellular nutritional states. Our study reveals a novel regulatory mechanism underlying carbohydrate metabolism, and suggests new possibilities for designing genetic engineering approaches to improve the rate of utilization of starch in actinobacteria.IMPORTANCE The development of efficient strategies for utilization of biomass-derived sugars, such as starch and cellulose, remains a major technical challenge due to the weak activity of associated enzymes. Here, we found that GlnR and PhoP directly regulate the transcription of genes encoding amylolytic enzymes and present insights into the regulatory mechanisms of degradation and utilization of starch in actinobacteria. Two nutrient-sensing regulators may play important roles in creating a direct association between nitrogen/phosphate metabolisms and carbohydrate utilization, as well as modulate the C:N:P balance in response to cellular nutritional states. These findings highlight the interesting possibilities for designing genetic engineering approaches and optimizing the fermentation process to improve the utilization efficiency of sugars in actinobacteria via overexpression of the glnR and phoP genes and nutrient signal stimulation.
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