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Ibrahim MIA, Ibrahim HAH, Haga T, Ishida A, Nehira T, Matsuo K, Gad AM. Potential Bioactivities, Chemical Composition, and Conformation Studies of Exopolysaccharide-Derived Aspergillus sp. Strain GAD7. J Fungi (Basel) 2024; 10:659. [PMID: 39330418 PMCID: PMC11432975 DOI: 10.3390/jof10090659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2024] [Revised: 09/17/2024] [Accepted: 09/17/2024] [Indexed: 09/28/2024] Open
Abstract
This research identified a marine fungal isolate, Aspergillus sp. strain GAD7, which produces an acidic and sulfated extracellular polysaccharide (EPS) with notable anticoagulant and antioxidant properties. Six fungal strains from the Egyptian Mediterranean Sea were screened for EPS production, with Aspergillus sp. strain GAD7 (EPS-AG7) being the most potent, yielding ~5.19 ± 0.017 g/L. EPS-AG7 was characterized using UV-Vis and FTIR analyses, revealing high carbohydrate (87.5%) and sulfate (24%) contents. HPLC and GC-MS analyses determined that EPS-AG7 is a heterogeneous acidic polysaccharide with an average molecular weight (Mw¯) of ~7.34 × 103 Da, composed of mannose, glucose, arabinose, galacturonic acid, galactose, and lyxose in a molar ratio of 6.6:3.9:1.8:1.3:1.1:1.0, linked through α- and β-glycosidic linkages as confirmed by NMR analysis. EPS-AG7 adopted a triple helix-like conformation, as evidenced by UV-Vis (Congo Red experiment) and circular dichroism (CD) studies. This helical arrangement demonstrated stability under various experimental conditions, including concentration, ionic strength, temperature, and lipid interactions. EPS-AG7 exhibited significant anticoagulant activity, doubling blood coagulation time at a concentration of 3.0 mg/mL, and showed significant antioxidant activity, with scavenging activities reaching up to 85.90% and 58.64% in DPPH and ABTS+ assays at 5.0 mg/mL, and EC50 values of 1.40 mg/mL and 3.80 mg/mL, respectively. These findings highlight the potential of EPS-AG7 for therapeutic applications due to its potent biological activities.
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Affiliation(s)
- Mohamed I A Ibrahim
- Research Institute for Synchrotron Radiation Science, HiSOR, Hiroshima University, Higashi-Hiroshima 739-0046, Hiroshima, Japan
- National Institute of Oceanography and Fisheries (NIOF), Cairo 4262110, Egypt
| | - Hassan A H Ibrahim
- National Institute of Oceanography and Fisheries (NIOF), Cairo 4262110, Egypt
| | - Tatsuki Haga
- Research Institute for Synchrotron Radiation Science, HiSOR, Hiroshima University, Higashi-Hiroshima 739-0046, Hiroshima, Japan
| | - Atsuhiko Ishida
- Laboratory of Molecular Brain Science, Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima 739-8521, Hiroshima, Japan
| | - Tatsuo Nehira
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima 739-8521, Hiroshima, Japan
| | - Koichi Matsuo
- Research Institute for Synchrotron Radiation Science, HiSOR, Hiroshima University, Higashi-Hiroshima 739-0046, Hiroshima, Japan
- International Institute for Sustainability with Knotted Chiral Meta Matter (WPI-SKCM2), Hiroshima University, Higashi-Hiroshima 739-8526, Hiroshima, Japan
- Research Institute for Semiconductor Engineering, Hiroshima University, Higashi-Hiroshima 739-8527, Hiroshima, Japan
| | - Ahmed M Gad
- National Institute of Oceanography and Fisheries (NIOF), Cairo 4262110, Egypt
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Chatrath A, Dey P, Greeley K, Maciel G, Huang L, Heiss C, Black I, Azadi P, Free SJ. Characterization of the Neurospora crassa Galactosaminogalactan Biosynthetic Pathway. Microorganisms 2024; 12:1509. [PMID: 39203353 PMCID: PMC11356417 DOI: 10.3390/microorganisms12081509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2024] [Revised: 07/17/2024] [Accepted: 07/19/2024] [Indexed: 09/03/2024] Open
Abstract
The Neurospora crassa genome has a gene cluster for the synthesis of galactosaminogalactan (GAG). The gene cluster includes the following: (1) UDP-glucose-4-epimerase to convert UDP-glucose and UDP-N-acetylglucosamine to UDP-galactose and UDP-N-acetylgalactosamine (NCU05133), (2) GAG synthase for the synthesis of an acetylated GAG (NCU05132), (3) GAG deacetylase (/NCW-1/NCU05137), (4) GH135-1, a GAG hydrolase with specificity for N-acetylgalactosamine-containing GAG (NCU05135), and (5) GH114-1, a galactosaminidase with specificity for galactosamine-containing GAG (NCU05136). The deacetylase was previously shown to be a major cell wall glycoprotein and given the name of NCW-1 (non-GPI anchored cell wall protein-1). Characterization of the polysaccharides found in the growth medium from the wild type and the GAG synthase mutant demonstrates that there is a major reduction in the levels of polysaccharides containing galactosamine and N-acetylgalactosamine in the mutant growth medium, providing evidence that the synthase is responsible for the production of a GAG. The analysis also indicates that there are other galactose-containing polysaccharides produced by the fungus. Phenotypic characterization of wild-type and mutant isolates showed that deacetylated GAG from the wild type can function as an adhesin to a glass surface and provides the fungal mat with tensile strength, demonstrating that the deacetylated GAG functions as an intercellular adhesive. The acetylated GAG produced by the deacetylase mutant was found to function as an adhesive for chitin, alumina, celite (diatomaceous earth), activated charcoal, and wheat leaf particulates.
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Affiliation(s)
- Apurva Chatrath
- Department of Biological Sciences, SUNY University at Buffalo, Buffalo, NY 14260, USA; (A.C.); (K.G.)
| | - Protyusha Dey
- Department of Biological Sciences, SUNY University at Buffalo, Buffalo, NY 14260, USA; (A.C.); (K.G.)
| | - Kevin Greeley
- Department of Biological Sciences, SUNY University at Buffalo, Buffalo, NY 14260, USA; (A.C.); (K.G.)
| | - Gabriela Maciel
- Department of Biological Sciences, SUNY University at Buffalo, Buffalo, NY 14260, USA; (A.C.); (K.G.)
| | - Lei Huang
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA; (L.H.)
| | - Christian Heiss
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA; (L.H.)
| | - Ian Black
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA; (L.H.)
| | - Parastoo Azadi
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA; (L.H.)
| | - Stephen J. Free
- Department of Biological Sciences, SUNY University at Buffalo, Buffalo, NY 14260, USA; (A.C.); (K.G.)
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Miyazawa K, Umeyama T, Takatsuka S, Muraosa Y, Hoshino Y, Yano S, Abe K, Miyazaki Y. Real-time monitoring of mycelial growth in liquid culture using hyphal dispersion mutant of Aspergillus fumigatus. Med Mycol 2024; 62:myae011. [PMID: 38429972 DOI: 10.1093/mmy/myae011] [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: 11/02/2023] [Revised: 01/29/2024] [Accepted: 02/29/2024] [Indexed: 03/03/2024] Open
Abstract
Hyphal pellet formation by Aspergillus species in liquid cultures is one of the main obstacles to high-throughput anti-Aspergillus reagent screening. We previously constructed a hyphal dispersion mutant of Aspergillus fumigatus by disrupting the genes encoding the primary cell wall α-1,3-glucan synthase Ags1 and putative galactosaminogalactan synthase Gtb3 (Δags1Δgtb3). Mycelial growth of the mutant in liquid cultures monitored by optical density was reproducible, and the dose-response of hyphal growth to antifungal agents has been quantified by optical density. However, Δags1Δgtb3 still forms hyphal pellets in some rich growth media. Here, we constructed a disruptant lacking all three α-1,3-glucan synthases and galactosaminogalactan synthase (Δags1Δags2Δags3Δgtb3), and confirmed that its hyphae were dispersed in all the media tested. We established an automatic method to monitor hyphal growth of the mutant in a 24-well plate shaken with a real-time plate reader. Dose-dependent growth suppression and unique growth responses to antifungal agents (voriconazole, amphotericin B, and micafungin) were clearly observed. A 96-well plate was also found to be useful for the evaluation of mycelial growth by optical density. Our method is potentially applicable to high-throughput screening for anti-Aspergillus agents.
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Affiliation(s)
- Ken Miyazawa
- Department of Fungal Infection, National Institute of Infectious Diseases, Tokyo, Japan
| | - Takashi Umeyama
- Department of Fungal Infection, National Institute of Infectious Diseases, Tokyo, Japan
| | - Shogo Takatsuka
- Department of Fungal Infection, National Institute of Infectious Diseases, Tokyo, Japan
| | - Yasunori Muraosa
- Department of Fungal Infection, National Institute of Infectious Diseases, Tokyo, Japan
| | - Yasutaka Hoshino
- Department of Fungal Infection, National Institute of Infectious Diseases, Tokyo, Japan
| | - Shigekazu Yano
- Graduate School of Sciences and Engineering, Yamagata University, Yonezawa, Japan
| | - Keietsu Abe
- Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Yoshitsugu Miyazaki
- Department of Fungal Infection, National Institute of Infectious Diseases, Tokyo, Japan
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Li Q, Wang C, Xiao H, Zhang Y, Xie Y. 2-Hydroxy-4-methoxybenzaldehyde, a more effective antifungal aroma than vanillin and its derivatives against Fusarium graminearum, destroys cell membranes, inhibits DON biosynthesis, and performs a promising antifungal effect on wheat grains. Front Microbiol 2024; 15:1359947. [PMID: 38468857 PMCID: PMC10925628 DOI: 10.3389/fmicb.2024.1359947] [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: 12/22/2023] [Accepted: 02/13/2024] [Indexed: 03/13/2024] Open
Abstract
Fusarium graminearum (F. graminearum) is a severe pathogen threatening the safety of agriculture and food. This study aimed to explore the antifungal efficacies of several plant-derived natural compounds (vanillin and its derivatives) against the growth of F. graminearum and investigate the antifungal mechanism of 2-hydroxy-4-methoxybenzaldehyde (HMB), the strongest one. The minimum inhibitory concentration (MIC) of HMB in inhibiting mycelial growth was 200 μg/mL. HMB at MIC damaged cell membranes by increasing the permeability by about 6-fold (p < 0.05) as evidenced by propidium iodide (PI) staining. Meanwhile, the content of malondialdehyde (MDA) and glycerol was increased by 45.91 and 576.19% by HMB treatment at MIC, respectively, indicating that lipid oxidation and osmotic stress occurred in the cell membrane. Furthermore, HMB exerted a strong antitoxigenic role as the content of deoxynivalenol (DON) was remarkably reduced by 93.59% at MIC on 7th day. At last, the antifungal effect of HMB against F. graminearum was also confirmed on wheat grains. These results not only revealed the antifungal mechanism of HMB but also suggested that HMB could be applied as a promising antifungal agent in the preservation of agricultural products.
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Affiliation(s)
- Qian Li
- Grain, Oil and Food Engineering Technology Research Center of the State Grain and Reserves Administration/Key Laboratory of Henan Province, Henan University of Technology, Zhengzhou, Henan, China
- Henan Key laboratory of Cereal and Oil Food Safety and Nutrition, College of Food Science and Engineering, Henan University of Technology, Zhengzhou, Henan, China
| | - Chong Wang
- Grain, Oil and Food Engineering Technology Research Center of the State Grain and Reserves Administration/Key Laboratory of Henan Province, Henan University of Technology, Zhengzhou, Henan, China
- Henan Key laboratory of Cereal and Oil Food Safety and Nutrition, College of Food Science and Engineering, Henan University of Technology, Zhengzhou, Henan, China
| | - Hongying Xiao
- Grain, Oil and Food Engineering Technology Research Center of the State Grain and Reserves Administration/Key Laboratory of Henan Province, Henan University of Technology, Zhengzhou, Henan, China
- Henan Key laboratory of Cereal and Oil Food Safety and Nutrition, College of Food Science and Engineering, Henan University of Technology, Zhengzhou, Henan, China
| | - Yiming Zhang
- Grain, Oil and Food Engineering Technology Research Center of the State Grain and Reserves Administration/Key Laboratory of Henan Province, Henan University of Technology, Zhengzhou, Henan, China
- Henan Key laboratory of Cereal and Oil Food Safety and Nutrition, College of Food Science and Engineering, Henan University of Technology, Zhengzhou, Henan, China
| | - Yanli Xie
- Grain, Oil and Food Engineering Technology Research Center of the State Grain and Reserves Administration/Key Laboratory of Henan Province, Henan University of Technology, Zhengzhou, Henan, China
- Henan Key laboratory of Cereal and Oil Food Safety and Nutrition, College of Food Science and Engineering, Henan University of Technology, Zhengzhou, Henan, China
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Miyazawa K, Umeyama T, Yoshimi A, Abe K, Miyazaki Y. [Aspergillus Cell Surface Structural Analysis and Its Applications to Industrial and Medical Use]. Med Mycol J 2024; 65:75-82. [PMID: 39218650 DOI: 10.3314/mmj.24.007] [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] [Indexed: 09/04/2024]
Abstract
The hyphal surface of cells of filamentous fungi is covered with cell wall, which is mainly composed of polysaccharides. Since the cell wall is the first structure to come in contact with the infection host, the environment, and the fungus itself, the elucidation of the cell wall structure and biogenesis is essential for understanding fungal ecology. Among filamentous fungi, the genus Aspergillus is an important group in the industrial, food, and medical fields. It is known that Aspergillus species form hyphal pellets in shake liquid culture. The authors previously found the role of α-1,3-glucan in hyphal aggregation in Aspergillus species. In addition, extracellular polysaccharide galactosaminogalactan contributed to hyphal aggregation as well, and dual disruption of biosynthesis genes of α-1,3-glucan and galactosaminogalactan resulted in complete hyphal dispersion in shake liquid culture. The characteristic of mycelia to form pellets under liquid culture conditions was the main reason why the growth measurement methods used for unicellular organisms could not be applied. We reported that hyphal growth of the dual disruption mutant could be measured by optical density. A real-time plate reader could be used to determine the growth curve of the mycelial growth of the dual disruption mutant. This measurement approach not only provides basic microbiological insights in filamentous fungi, but also has the potential to be applied to high-throughput screening of anti-Aspergillus drugs.
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Affiliation(s)
- Ken Miyazawa
- Department of Fungal Infection, National Institute of Infectious Diseases
| | - Takashi Umeyama
- Department of Fungal Infection, National Institute of Infectious Diseases
| | - Akira Yoshimi
- Terrestrial Microbiology and Systematics, Graduate School of Global Environmental Studies, Kyoto University
- New Industry Creation Hatchery Center, Tohoku University
| | - Keietsu Abe
- New Industry Creation Hatchery Center, Tohoku University
- Department of Agricultural Chemistry, Graduate School of Agricultural Sciences, Tohoku University
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Li Q, Lu J, Liu J, Li J, Zhang G, Du G, Chen J. High-throughput droplet microfluidics screening and genome sequencing analysis for improved amylase-producing Aspergillus oryzae. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:185. [PMID: 38031105 PMCID: PMC10685594 DOI: 10.1186/s13068-023-02437-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 11/21/2023] [Indexed: 12/01/2023]
Abstract
BACKGROUND The exceptional protein secretion capacity, intricate post-translational modification processes, and inherent safety features of A. oryzae make it a promising expression system. However, heterologous protein expression levels of existing A. oryzae species cannot meet the requirement for industrial-scale production. Therefore, establishing an efficient screening technology is significant for the development of the A. oryzae expression system. RESULTS In this work, a high-throughput screening method suitable for A. oryzae has been established by combining the microfluidic system and flow cytometry. Its screening efficiency can reach 350 droplets per minute. The diameter of the microdroplet was enlarged to 290 µm to adapt to the polar growth of A. oryzae hyphae. Through enrichment and screening from approximately 450,000 droplets within 2 weeks, a high-producing strain with α-amylase increased by 6.6 times was successfully obtained. Furthermore, 29 mutated genes were identified by genome resequencing of high-yield strains, with 15 genes subjected to editing and validation. Two genes may individually influence α-amylase expression in A. oryzae by affecting membrane-associated multicellular processes and regulating the transcription of related genes. CONCLUSIONS The developed high-throughput screening strategy provides a reference for other filamentous fungi and Streptomyces. Besides, the strains with different excellent characteristics obtained by efficient screening can also provide materials for the analysis of genetic and regulatory mechanisms in the A. oryzae expression system.
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Affiliation(s)
- Qinghua Li
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
- National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
| | - Jinchang Lu
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
- National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
| | - Jingya Liu
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
- National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
| | - Jianghua Li
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
- School of Biotechnology and Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
| | - Guoqiang Zhang
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.
- National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.
| | - Guocheng Du
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
- School of Biotechnology and Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
| | - Jian Chen
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
- National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
- School of Biotechnology and Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
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Liu H, Luo Z, Rao Y. Manipulation of fungal cell wall integrity to improve production of fungal natural products. ADVANCES IN APPLIED MICROBIOLOGY 2023; 125:49-78. [PMID: 38783724 DOI: 10.1016/bs.aambs.2023.07.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2024]
Abstract
Fungi, as an important industrial microorganism, play an essential role in the production of natural products (NPs) due to their advantages of utilizing cheap raw materials as substrates and strong protein secretion ability. Although many metabolic engineering strategies have been adopted to enhance the biosynthetic pathway of NPs in fungi, the fungal cell wall as a natural barrier tissue is the final and key step that affects the efficiency of NPs synthesis. To date, many important progresses have been achieved in improving the synthesis of NPs by regulating the cell wall structure of fungi. In this review, we systematically summarize and discuss various strategies for modifying the cell wall structure of fungi to improve the synthesis of NPs. At first, the cell wall structure of different types of fungi is systematically described. Then, strategies to disrupt cell wall integrity (CWI) by regulating the synthesis of cell wall polysaccharides and binding proteins are summarized, which have been applied to improve the synthesis of NPs. In addition, we also summarize the studies on the regulation of CWI-related signaling pathway and the addition of exogenous components for regulating CWI to improve the synthesis of NPs. Finally, we propose the current challenges and essential strategies to usher in an era of more extensive manipulation of fungal CWI to improve the production of fungal NPs.
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Affiliation(s)
- Huiling Liu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, P.R. China
| | - Zhengshan Luo
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, P.R. China
| | - Yijian Rao
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, P.R. China.
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Tsumori C, Matsuo S, Murai Y, Kai K. Quorum Sensing-Dependent Invasion of Ralstonia solanacearum into Fusarium oxysporum Chlamydospores. Microbiol Spectr 2023; 11:e0003623. [PMID: 37367297 PMCID: PMC10433826 DOI: 10.1128/spectrum.00036-23] [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: 01/03/2023] [Accepted: 06/02/2023] [Indexed: 06/28/2023] Open
Abstract
Strains of the Ralstonia solanacearum species complex (RSSC), although known as the causative agent of bacterial wilt disease in plants, induce the chlamydospores of many fungal species and invade them through the spores. The lipopeptide ralstonins are the chlamydospore inducers produced by RSSC and are essential for this invasion. However, no mechanistic investigation of this interaction has been conducted. In this study, we report that quorum sensing (QS), which is a bacterial cell-cell communication, is important for RSSC to invade the fungus Fusarium oxysporum (Fo). ΔphcB, a deletion mutant of QS signal synthase, lost the ability to both produce ralstonins and invade Fo chlamydospores. The QS signal methyl 3-hydroxymyristate rescued these disabilities. In contrast, exogenous ralstonin A, while inducing Fo chlamydospores, failed to rescue the invasive ability. Gene-deletion and -complementation experiments revealed that the QS-dependent production of extracellular polysaccharide I (EPS I) is essential for this invasion. The RSSC cells adhered to Fo hyphae and formed biofilms there before inducing chlamydospores. This biofilm formation was not observed in the EPS I- or ralstonin-deficient mutant. Microscopic analysis showed that RSSC infection resulted in the death of Fo chlamydospores. Altogether, we report that the RSSC QS system is important for this lethal endoparasitism. Among the factors regulated by the QS system, ralstonins, EPS I, and biofilm are important parasitic factors. IMPORTANCE Ralstonia solanacearum species complex (RSSC) strains infect both plants and fungi. The phc quorum-sensing (QS) system of RSSC is important for parasitism on plants, because it allows them to invade and proliferate within the hosts by causing appropriate activation of the system at each infection step. In this study, we confirm that ralstonin A is important not only for Fusarium oxysporum (Fo) chlamydospore induction but also for RSSC biofilm formation on Fo hyphae. Extracellular polysaccharide I (EPS I) is also essential for biofilm formation, while the phc QS system controls these factors in terms of production. The present results advocate a new QS-dependent mechanism for the process by which a bacterium invades a fungus.
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Affiliation(s)
- Chiaki Tsumori
- Graduate School of Agriculture, Osaka Metropolitan University, Osaka, Japan
| | - Shoma Matsuo
- Graduate School of Agriculture, Osaka Metropolitan University, Osaka, Japan
| | - Yuta Murai
- Graduate School of Agriculture, Osaka Metropolitan University, Osaka, Japan
| | - Kenji Kai
- Graduate School of Agriculture, Osaka Metropolitan University, Osaka, Japan
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Tamano K, Brown DW, Yoshimi A. Editorial: The use of metabolic engineering techniques to increase the productivity of primary and secondary metabolites within filamentous fungi. FRONTIERS IN FUNGAL BIOLOGY 2023; 4:1178290. [PMID: 37746119 PMCID: PMC10512314 DOI: 10.3389/ffunb.2023.1178290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 04/11/2023] [Indexed: 09/26/2023]
Affiliation(s)
- Koichi Tamano
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Sapporo, Japan
- Computational Bio Big-Data Open Innovation Laboratory (CBBD-OIL), National Institute of Advanced Industrial Science and Technology (AIST), Tokyo, Japan
| | - Daren W. Brown
- Mycotoxin Prevention and Applied Microbiology Research (MPM), National Center for Agricultural Utilization Research (NCAUR), Agricultural Research Service, USDA, Peoria, IL, United States
| | - Akira Yoshimi
- Laboratory of Environmental Interface Technology of Filamentous Fungi, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
- Laboratory of Terrestrial Microbial Ecology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
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Tamano K, Nakai S, Takayama H, Imai Y. Overexpression of a predicted transketolase gene and disruption of an α-1,3-glucan synthase gene in Aspergillus oryzae DGLA3 strain enhances the yield of free dihomo-γ-linolenic acid. Biosci Biotechnol Biochem 2023; 87:448-457. [PMID: 36617231 DOI: 10.1093/bbb/zbad003] [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: 07/28/2022] [Accepted: 12/27/2022] [Indexed: 01/09/2023]
Abstract
Free dihomo-γ-linolenic acid (DGLA), a polyunsaturated free fatty acid (FFA), can potentially be used to produce eicosanoid pharmaceuticals, such as prostaglandin E1. Previously, we constructed an Aspergillus oryzae mutant strain, named DGLA3, which produced free DGLA at an increased yield by faaA gene disruption and cooverexpression of one elongase and two desaturase genes. In this study, we achieved a further increase. Since FFA production is increased by enhancing the pentose phosphate pathway, we overexpressed a predicted transketolase gene composing the pathway in DGLA3, which consequently increased the free DGLA yield by 1.9-fold to 403 mg/L. Additionally, we disrupted the α-1,3-glucan synthase gene agsB involved in cell-wall biosynthesis, which further increased it by 1.3-fold to 533 mg/L. Overall, the yield increased by 2.5-fold. Free DGLA productivity and biomass increased similarly, but residual glucose concentration decreased. Increased hyphal dispersion appeared to cause additional glucose consumption, resulting in an increase in biomass and yield.
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Affiliation(s)
- Koichi Tamano
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Sapporo, Hokkaido, Japan
- AIST-Waseda University Computational Bio Big-Data Open Innovation Laboratory (CBBD-OIL), AIST, Shinjuku-ku, Tokyo, Japan
| | - Shiori Nakai
- Hokkaido High-Technology College, Eniwa, Hokkaido, Japan
| | - Haruka Takayama
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Sapporo, Hokkaido, Japan
| | - Yasuhiko Imai
- Noda Institute for Scientific Research, Noda, Chiba, Japan
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Kadooka C, Tanaka Y, Hira D, Maruyama JI, Goto M, Oka T. Identification of galactofuranose antigens such as galactomannoproteins and fungal-type galactomannan from the yellow koji fungus ( Aspergillus oryzae). Front Microbiol 2023; 14:1110996. [PMID: 36814571 PMCID: PMC9939772 DOI: 10.3389/fmicb.2023.1110996] [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: 11/29/2022] [Accepted: 01/16/2023] [Indexed: 02/08/2023] Open
Abstract
Filamentous fungi belonging to the genus Aspergillus are known to possess galactomannan in their cell walls. Galactomannan is highly antigenic to humans and has been reported to be involved in the pathogenicity of pathogenic filamentous fungi, such as A. fumigatus, and in immune responses. In this study, we aimed to confirm the presence of D-galactofuranose-containing glycans and to clarify the biosynthesis of D-galactofuranose-containing glycans in Aspergillus oryzae, a yellow koji fungus. We found that the galactofuranose antigen is also present in A. oryzae. Deletion of ugmA, which encodes UDP-galactopyranose mutase in A. oryzae, suppressed mycelial elongation, suggesting that D-galactofuranose-containing glycans play an important role in cell wall integrity in A. oryzae. Proton nuclear magnetic resonance spectrometry revealed that the galactofuranose-containing sugar chain was deficient and that core mannan backbone structures were present in ΔugmA A. oryzae, indicating the presence of fungal-type galactomannan in the cell wall fraction of A. oryzae. The findings of this study provide new insights into the cell wall structure of A. oryzae, which is essential for the production of fermented foods in Japan.
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Affiliation(s)
- Chihiro Kadooka
- Department of Biotechnology and Life Sciences, Faculty of Biotechnology and Life Sciences, Sojo University, Kumamoto, Japan
| | - Yutaka Tanaka
- Division of Infection and Host Defense, Tohoku Medical and Pharmaceutical University, Sendai, Japan
| | - Daisuke Hira
- Department of Biotechnology and Life Sciences, Faculty of Biotechnology and Life Sciences, Sojo University, Kumamoto, Japan
| | - Jun-ichi Maruyama
- Department of Biotechnology, The University of Tokyo, Tokyo, Japan,Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo, Japan
| | - Masatoshi Goto
- Department of Applied Biochemistry and Food Science, Faculty of Agriculture, Saga University, Saga, Japan
| | - Takuji Oka
- Department of Biotechnology and Life Sciences, Faculty of Biotechnology and Life Sciences, Sojo University, Kumamoto, Japan,*Correspondence: Takuji Oka,
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12
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Koizumi A, Miyazawa K, Ogata M, Takahashi Y, Yano S, Yoshimi A, Sano M, Hidaka M, Nihira T, Nakai H, Kimura S, Iwata T, Abe K. Cleavage of α-1,4-glycosidic linkages by the glycosylphosphatidylinositol-anchored α-amylase AgtA decreases the molecular weight of cell wall α-1,3-glucan in Aspergillus oryzae. FRONTIERS IN FUNGAL BIOLOGY 2023; 3:1061841. [PMID: 37746167 PMCID: PMC10512346 DOI: 10.3389/ffunb.2022.1061841] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 11/29/2022] [Indexed: 09/26/2023]
Abstract
Aspergillus fungi contain α-1,3-glucan with a low proportion of α-1,4-glucan as a major cell wall polysaccharide. Glycosylphosphatidylinositol (GPI)-anchored α-amylases are conserved in Aspergillus fungi. The GPI-anchored α-amylase AmyD in Aspergillus nidulans has been reported to directly suppress the biosynthesis of cell wall α-1,3-glucan but not to degrade it in vivo. However, the detailed mechanism of cell wall α-1,3-glucan biosynthesis regulation by AmyD remains unclear. Here we focused on AoAgtA, which is encoded by the Aspergillus oryzae agtA gene, an ortholog of the A. nidulans amyD gene. Similar to findings in A. nidulans, agtA overexpression in A. oryzae grown in submerged culture decreased the amount of cell wall α-1,3-glucan and led to the formation of smaller hyphal pellets in comparison with the wild-type strain. We analyzed the enzymatic properties of recombinant (r)AoAgtA produced in Pichia pastoris and found that it degraded soluble starch, but not linear bacterial α-1,3-glucan. Furthermore, rAoAgtA cleaved 3-α-maltotetraosylglucose with a structure similar to the predicted boundary structure between the α-1,3-glucan main chain and a short spacer composed of α-1,4-linked glucose residues in cell wall α-1,3-glucan. Interestingly, rAoAgtA randomly cleaved only the α-1,4-glycosidic bonds of 3-α-maltotetraosylglucose, indicating that AoAgtA may cleave the spacer in cell wall α-1,3-glucan. Consistent with this hypothesis, heterologous overexpression of agtA in A. nidulans decreased the molecular weight of cell wall α-1,3-glucan. These in vitro and in vivo properties of AoAgtA suggest that GPI-anchored α-amylases can degrade the spacer α-1,4-glycosidic linkages in cell wall α-1,3-glucan before its insolubilization, and this spacer cleavage decreases the molecular weight of cell wall α-1,3-glucan in vivo.
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Affiliation(s)
- Ami Koizumi
- Laboratory of Applied Microbiology, Department of Biochemistry, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Ken Miyazawa
- Laboratory of Applied Microbiology, Department of Biochemistry, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
- Laboratory of Filamentous Mycoses, Department of Fungal Infection, National Institute of Infectious Diseases, Tokyo, Japan
| | - Makoto Ogata
- Faculty of Food and Agricultural Sciences, Fukushima University, Fukushima, Japan
| | - Yuzuru Takahashi
- Department of Biochemical Engineering, Graduate School of Science and Engineering, Yamagata University, Yonezawa, Japan
| | - Shigekazu Yano
- Department of Biochemical Engineering, Graduate School of Science and Engineering, Yamagata University, Yonezawa, Japan
| | - Akira Yoshimi
- ABE-Project, New Industry Creation Hatchery Center, Tohoku University, Sendai, Japan
- Laboratory of Environmental Interface Technology of Filamentous Fungi, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
- Laboratory of Terrestrial Microbial Ecology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Motoaki Sano
- Genome Biotechnology Laboratory, Kanazawa Institute of Technology, Hakusan, Japan
| | - Masafumi Hidaka
- Laboratory of Enzymology, Department of Biochemistry, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | | | - Hiroyuki Nakai
- Faculty of Agriculture, Niigata University, Niigata, Japan
| | - Satoshi Kimura
- Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Tadahisa Iwata
- Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Keietsu Abe
- Laboratory of Applied Microbiology, Department of Biochemistry, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
- ABE-Project, New Industry Creation Hatchery Center, Tohoku University, Sendai, Japan
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13
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Evidencing New Roles for the Glycosyl-Transferase Cps1 in the Phytopathogenic Fungus Botrytis cinerea. J Fungi (Basel) 2022; 8:jof8090899. [PMID: 36135623 PMCID: PMC9500679 DOI: 10.3390/jof8090899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 08/13/2022] [Accepted: 08/16/2022] [Indexed: 11/28/2022] Open
Abstract
The fungal cell wall occupies a central place in the interaction between fungi and their environment. This study focuses on the role of the putative polysaccharide synthase Cps1 in the physiology, development and virulence of the grey mold-causing agent Botrytis cinerea. Deletion of the Bccps1 gene does not affect the germination of the conidia (asexual spores) or the early mycelial development, but it perturbs hyphal expansion after 24 h, revealing a two-phase hyphal development that has not been reported so far. It causes a severe reduction of mycelial growth in a solid medium and modifies hyphal aggregation into pellets in liquid cultures. It strongly impairs plant penetration, plant colonization and the formation of sclerotia (survival structures). Loss of the BcCps1 protein associates with a decrease in glucans and glycoproteins in the fungus cell wall and the up-accumulation of 132 proteins in the mutant’s exoproteome, among which are fungal cell wall enzymes. This is accompanied by an increased fragility of the mutant mycelium, an increased sensitivity to some environmental stresses and a reduced adhesion to plant surface. Taken together, the results support a significant role of Cps1 in the cell wall biology of B. cinerea.
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14
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Otsuka Y, Sasaki K, Suyotha W, Furusawa H, Miyazawa K, Konno H, Yano S. Construction of a fusion protein consisting of α-1,3-glucan-binding domains and tetrameric red fluorescent protein, which is involved in the aggregation of α-1,3-glucan and inhibition of fungal biofilm formation. J Biosci Bioeng 2022; 133:524-532. [PMID: 35314116 DOI: 10.1016/j.jbiosc.2022.02.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 02/18/2022] [Accepted: 02/18/2022] [Indexed: 11/24/2022]
Abstract
Agl-KA, an α-1,3-glucan-hydrolyzing enzyme from Bacillus circulans KA-304, has three α-1,3-glucan-binding domains DS1, CB6, and DS2 (DCD). While their individual binding activities toward insoluble α-1,3-glucan and fungal cell-wall are weak, the three domains in combination bind strongly to the α-1,3-glucan and the cell-wall. In this study, we constructed DCD-tetraRFP by fusing DCD with DsRed-Express2, a tetrameric red fluorescent protein. DCD-tetraRFP forms a tetramer in an aqueous solution and contains twelve substrate-binding domains in one complex. We also constructed DCD-monoGFP by fusing DCD with AcGFP1, a monomeric green fluorescent protein. The molecular weight of DCD-tetraRFP and DCD-monoGFP were compared. The results of gel filtration chromatography and dynamic light scattering indicated that DCD-tetraRFP was larger than DCD-monoGFP, suggesting that DCD-tetraRFP had a tetrameric structure. In addition, DCD-tetraRFP bound to insoluble α-1,3-glucan strongly, and the amount of DCD-tetraRFP binding to 0.01% α-1,3-glucan was about twice of DCD-monoGFP. The Kd values of DCD-tetraRFP (measurements per subunit) and DCD-monoGFP were 0.16 and 0.84 μM, respectively. Adding DCD-tetraRFP to a suspension of α-1,3-glucan caused glucan aggregation; however, adding DCD-monoGFP did not. These data suggested that DCD-tetraRFP had four DCDs sterically arranged in different directions so that DCD-tetraRFP cross-linked with the substrate, causing aggregation. Lastly, the aggregates of DCD-tetraRFP and α-1,3-glucan captured Aspergillus oryzae conidia and decreased their biofilm formation by 80% in a 24-well dish.
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Affiliation(s)
- Yuitsu Otsuka
- Graduate School of Sciences and Engineering, Yamagata University, Jonan, Yonezawa, Yamagata 992-8510, Japan
| | - Kai Sasaki
- Graduate School of Sciences and Engineering, Yamagata University, Jonan, Yonezawa, Yamagata 992-8510, Japan
| | - Wasana Suyotha
- Department of Industrial Biotechnology, Faculty of Agro-industry, Prince of Songkla University, Hat Yai 90112, Thailand
| | - Hiroyuki Furusawa
- Graduate School of Sciences and Engineering, Yamagata University, Jonan, Yonezawa, Yamagata 992-8510, Japan
| | - Ken Miyazawa
- Laboratory of Filamentous Mycoses, Department of Fungal Infection, National Institute of Infectious Diseases, Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| | - Hiroyuki Konno
- Graduate School of Sciences and Engineering, Yamagata University, Jonan, Yonezawa, Yamagata 992-8510, Japan
| | - Shigekazu Yano
- Graduate School of Sciences and Engineering, Yamagata University, Jonan, Yonezawa, Yamagata 992-8510, Japan.
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15
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Yoshimi A, Miyazawa K, Kawauchi M, Abe K. Cell Wall Integrity and Its Industrial Applications in Filamentous Fungi. J Fungi (Basel) 2022; 8:435. [PMID: 35628691 PMCID: PMC9148135 DOI: 10.3390/jof8050435] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 04/15/2022] [Accepted: 04/20/2022] [Indexed: 11/20/2022] Open
Abstract
Signal transduction pathways regulating cell wall integrity (CWI) in filamentous fungi have been studied taking into account findings in budding yeast, and much knowledge has been accumulated in recent years. Given that the cell wall is essential for viability in fungi, its architecture has been analyzed in relation to virulence, especially in filamentous fungal pathogens of plants and humans. Although research on CWI signaling in individual fungal species has progressed, an integrated understanding of CWI signaling in diverse fungi has not yet been achieved. For example, the variety of sensor proteins and their functional differences among different fungal species have been described, but the understanding of their general and species-specific biological functions is limited. Our long-term research interest is CWI signaling in filamentous fungi. Here, we outline CWI signaling in these fungi, from sensor proteins required for the recognition of environmental changes to the regulation of cell wall polysaccharide synthesis genes. We discuss the similarities and differences between the functions of CWI signaling factors in filamentous fungi and in budding yeast. We also describe the latest findings on industrial applications, including those derived from studies on CWI signaling: the development of antifungal agents and the development of highly productive strains of filamentous fungi with modified cell surface characteristics by controlling cell wall biogenesis.
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Affiliation(s)
- Akira Yoshimi
- Laboratory of Environmental Interface Technology of Filamentous Fungi, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan; (A.Y.); (M.K.)
- ABE-Project, New Industry Creation Hatchery Center, Tohoku University, Sendai 980-8579, Japan
| | - Ken Miyazawa
- ABE-Project, New Industry Creation Hatchery Center, Tohoku University, Sendai 980-8579, Japan
- Laboratory of Filamentous Mycoses, Department of Fungal Infection, National Institute of Infectious Diseases, Tokyo 162-8640, Japan;
| | - Moriyuki Kawauchi
- Laboratory of Environmental Interface Technology of Filamentous Fungi, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan; (A.Y.); (M.K.)
| | - Keietsu Abe
- ABE-Project, New Industry Creation Hatchery Center, Tohoku University, Sendai 980-8579, Japan
- Laboratory of Applied Microbiology, Graduate School of Agricultural Science, Tohoku University, Sendai 980-8572, Japan
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16
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Miyazawa K, Umeyama T, Hoshino Y, Abe K, Miyazaki Y. Quantitative Monitoring of Mycelial Growth of Aspergillus fumigatus in Liquid Culture by Optical Density. Microbiol Spectr 2022; 10:e0006321. [PMID: 34985327 PMCID: PMC8729762 DOI: 10.1128/spectrum.00063-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 11/17/2021] [Indexed: 01/24/2023] Open
Abstract
Filamentous fungi form multicellular hyphae, which generally form pellets in liquid shake cultures, during the vegetative growth stage. Because of these characteristics, growth-monitoring methods commonly used in bacteria and yeast have not been applied to filamentous fungi. We have recently revealed that the cell wall polysaccharide α-1,3-glucan and extracellular polysaccharide galactosaminogalactan (GAG) contribute to hyphal aggregation in Aspergillus oryzae. Here, we tested whether Aspergillus fumigatus shows dispersed growth in liquid media that can be quantitatively monitored, similar to that of yeasts. We constructed a double disruptant mutant of both the primary α-1,3-glucan synthase gene ags1 and the putative GAG synthase gene gtb3 in A. fumigatus AfS35 and found that the hyphae of this mutant were fully dispersed. Although the mutant lost α-1,3-glucan and GAG, its growth and susceptibility to antifungal agents were not different from those of the parental strain. Mycelial weight of the mutant in shake-flask cultures was proportional to optical density for at least 18 h. We were also able to quantify the dose response of hyphal growth to antifungal agents by measuring optical density. Overall, we established a convenient strategy to monitor A. fumigatus hyphal growth. Our method can be directly used for screening for novel antifungals against Aspergillus species. IMPORTANCE Filamentous fungi generally form hyphal pellets in liquid culture. This property prevents filamentous fungi so that we may apply the methods used for unicellular organisms such as yeast and bacteria. In the present study, by using the fungal pathogen Aspergillus fumigatus strain with modified hyphal surface polysaccharides, we succeeded in monitoring the hyphal growth quantitatively by optical density. The principle of this easy measurement by optical density could lead to a novel standard of hyphal quantification such as those that have been used for yeasts and bacteria. Dose response of hyphal growth by antifungal agents could also be monitored. This method could be useful for screening for novel antifungal reagents against Aspergillus species.
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Affiliation(s)
- Ken Miyazawa
- Department of Fungal Infection, National Institute of Infectious Diseases, Tokyo, Japan
| | - Takashi Umeyama
- Department of Fungal Infection, National Institute of Infectious Diseases, Tokyo, Japan
| | - Yasutaka Hoshino
- Department of Fungal Infection, National Institute of Infectious Diseases, Tokyo, Japan
| | - Keietsu Abe
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Yoshitsugu Miyazaki
- Department of Fungal Infection, National Institute of Infectious Diseases, Tokyo, Japan
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17
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Tong LL, Wang Y, Yuan L, Liu MZ, Du YH, Mu XY, Yang QH, Wei SX, Li JY, Wang M, Guo DS. Enhancement of polysaccharides production using microparticle enhanced technology by Paraisaria dubia. Microb Cell Fact 2022; 21:12. [PMID: 35090444 PMCID: PMC8796560 DOI: 10.1186/s12934-021-01733-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 12/25/2021] [Indexed: 02/07/2023] Open
Abstract
Background Polysaccharides are important active ingredients in Ophiocordyceps gracilis with many physiological functions. It can be obtained from the submerged fermentation by the anamorph (Paraisaria dubia) of Ophiocordyceps gracilis. However, it was found that the mycelial pellets of Paraisaria dubia were dense and increased in volume in the process of fermentation, and the center of the pellets was autolysis due to the lack of nutrient delivery, which extremely reduced the yield of polysaccharides. Therefore, it is necessary to excavate a fermentation strategy based on morphological regulation for Paraisaria dubia to promote polysaccharides accumulation. Results In this study, we developed a method for enhancing polysaccharides production by Paraisaria dubia using microparticle enhanced technology, talc microparticle as morphological inducer, and investigated the enhancement mechanisms by transcriptomics. The optimal size and dose of talc were found to be 2000 mesh and 15 g/L, which resulted in a high polysaccharides yield. It was found that the efficient synthesis of polysaccharides requires an appropriate mycelial morphology through morphological analysis of mycelial pellets. And, the polysaccharides synthesis was found to mainly rely on the ABC transporter-dependent pathway revealed by transcriptomics. This method was also showed excellent robustness in 5-L bioreactor, the maximum yields of intracellular polysaccharide and exopolysaccharides were 83.23 ± 1.4 and 518.50 ± 4.1 mg/L, respectively. And, the fermented polysaccharides were stable and showed excellent biological activity. Conclusions This study provides a feasible strategy for the efficient preparation of cordyceps polysaccharides via submerged fermentation with talc microparticles, which may also be applicable to similar macrofungi. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s12934-021-01733-w.
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Affiliation(s)
- Ling-Ling Tong
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, No. 1 Wenyuan Road, Nanjing, 210023, People's Republic of China
| | - Yue Wang
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, No. 1 Wenyuan Road, Nanjing, 210023, People's Republic of China
| | - Li Yuan
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, No. 1 Wenyuan Road, Nanjing, 210023, People's Republic of China
| | - Meng-Zhen Liu
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, No. 1 Wenyuan Road, Nanjing, 210023, People's Republic of China
| | - Yuan-Hang Du
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, No. 1 Wenyuan Road, Nanjing, 210023, People's Republic of China
| | - Xin-Ya Mu
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, No. 1 Wenyuan Road, Nanjing, 210023, People's Republic of China
| | - Qing-Hao Yang
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, No. 1 Wenyuan Road, Nanjing, 210023, People's Republic of China
| | - Shi-Xiang Wei
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, No. 1 Wenyuan Road, Nanjing, 210023, People's Republic of China
| | - Jun-Ya Li
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, No. 1 Wenyuan Road, Nanjing, 210023, People's Republic of China
| | - Mian Wang
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, No. 1 Wenyuan Road, Nanjing, 210023, People's Republic of China
| | - Dong-Sheng Guo
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, No. 1 Wenyuan Road, Nanjing, 210023, People's Republic of China.
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18
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Miyazawa K, Yamashita T, Takeuchi A, Kamachi Y, Yoshimi A, Tashiro Y, Koizumi A, Ogata M, Yano S, Kasahara S, Sano M, Yamagata Y, Nakajima T, Abe K. A Glycosylphosphatidylinositol-Anchored α-Amylase Encoded by amyD Contributes to a Decrease in the Molecular Mass of Cell Wall α-1,3-Glucan in Aspergillus nidulans. FRONTIERS IN FUNGAL BIOLOGY 2022; 2:821946. [PMID: 37744142 PMCID: PMC10512252 DOI: 10.3389/ffunb.2021.821946] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 12/22/2021] [Indexed: 09/26/2023]
Abstract
α-1,3-Glucan is one of the main polysaccharides in the cell wall of Aspergillus nidulans. We previously revealed that it plays a role in hyphal aggregation in liquid culture, and that its molecular mass (MM) in an agsA-overexpressing (agsAOE) strain was larger than that in an agsB-overexpressing (agsBOE) strain. The mechanism that regulates its MM is poorly understood. Although the gene amyD, which encodes glycosylphosphatidylinositol (GPI)-anchored α-amylase (AmyD), is involved in the biosynthesis of α-1,3-glucan in A. nidulans, how it regulates this biosynthesis remains unclear. Here we constructed strains with disrupted amyD (ΔamyD) or overexpressed amyD (amyDOE) in the genetic background of the ABPU1 (wild-type), agsAOE, or agsBOE strain, and characterized the chemical structure of α-1,3-glucans in the cell wall of each strain, focusing on their MM. The MM of α-1,3-glucan from the agsBOE amyDOE strain was smaller than that in the parental agsBOE strain. In addition, the MM of α-1,3-glucan from the agsAOE ΔamyD strain was greater than that in the agsAOE strain. These results suggest that AmyD is involved in decreasing the MM of α-1,3-glucan. We also found that the C-terminal GPI-anchoring region is important for these functions.
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Affiliation(s)
- Ken Miyazawa
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
- Laboratory of Filamentous Mycoses, Department of Fungal Infection, National Institute of Infectious Diseases, Tokyo, Japan
| | - Takaaki Yamashita
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Ayumu Takeuchi
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Yuka Kamachi
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Akira Yoshimi
- Laboratory of Environmental Interface Technology of Filamentous Fungi, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
- ABE-Project, New Industry Creation Hatchery Center, Tohoku University, Sendai, Japan
| | - Yuto Tashiro
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Ami Koizumi
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Makoto Ogata
- Faculty of Food and Agricultural Sciences, Fukushima University, Fukushima, Japan
| | - Shigekazu Yano
- Department of Biochemical Engineering, Graduate School of Engineering, Yamagata University, Yonezawa, Japan
| | - Shin Kasahara
- Food Microbiology Unit, School of Food and Agricultural Sciences, Miyagi University, Sendai, Japan
| | - Motoaki Sano
- Genome Biotechnology Laboratory, Kanazawa Institute of Technology, Hakusan, Japan
| | - Youhei Yamagata
- Department of Applied Life Science, The United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Fuchu, Japan
| | - Tasuku Nakajima
- ABE-Project, New Industry Creation Hatchery Center, Tohoku University, Sendai, Japan
| | - Keietsu Abe
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
- ABE-Project, New Industry Creation Hatchery Center, Tohoku University, Sendai, Japan
- Department of Microbial Resources, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
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19
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Ichikawa H, Miyazawa K, Komeiji K, Susukida S, Zhang S, Muto K, Orita R, Takeuchi A, Kamachi Y, Hitosugi M, Yoshimi A, Shintani T, Kato Y, Abe K. Improved recombinant protein production in Aspergillus oryzae lacking both α-1,3-glucan and galactosaminogalactan in batch culture with a lab-scale bioreactor. J Biosci Bioeng 2021; 133:39-45. [PMID: 34627690 DOI: 10.1016/j.jbiosc.2021.09.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 09/08/2021] [Accepted: 09/11/2021] [Indexed: 12/22/2022]
Abstract
Filamentous fungi are used as production hosts for various commercially valuable enzymes and chemicals including organic acids and secondary metabolites. We previously revealed that α-1,3-glucan and galactosaminogalactan (GAG) contribute to hyphal aggregation in the industrial fungus Aspergillus oryzae, and that production of recombinant protein in shake-flask culture is higher in a mutant lacking both α-1,3-glucan and GAG (AGΔ-GAGΔ) than in the parental strain. Here, we compared the productivity of the wild type, AGΔ-GAGΔ, and mutants lacking α-1,3-glucan (AGΔ) or GAG (GAGΔ) in batch culture with intermittent addition of glucose in a 5-L lab-scale bioreactor. The hyphae of the wild type and all mutants were dispersed by agitation, although the wild type and AGΔ formed small amounts of aggregates. Although mycelial weight was similar among the strains, the concentration of a secreted recombinant protein (CutL1) was the highest in AGΔ-GAGΔ. Evaluation of fluid properties revealed that the apparent viscosities of mycelial cultures of the wild type and AGΔ-GAGΔ decreased as the agitation speed was increased. The apparent viscosity of the AGΔ-GAGΔ culture tended to be lower than that of the wild-type strain at each agitation speed, and was significantly lower at 600 rpm. Overall, the lack of α-1,3-glucan and GAG in the hyphae improved culture rheology, resulting in an increase in recombinant protein production in AGΔ-GAGΔ. This is the first report of flow behavior improvement by a cell-surface component defect in a filamentous fungus.
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Affiliation(s)
- Hikaru Ichikawa
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Sciences, Tohoku University, 468-1 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8572, Japan
| | - Ken Miyazawa
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Sciences, Tohoku University, 468-1 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8572, Japan
| | - Keisuke Komeiji
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Sciences, Tohoku University, 468-1 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8572, Japan
| | - Shunya Susukida
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Sciences, Tohoku University, 468-1 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8572, Japan
| | - Silai Zhang
- Laboratory of Bioindustrial Genomics, Department of Bioindustrial Informatics and Genomics, Graduate School of Agricultural Sciences, Tohoku University, 468-1 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8572, Japan
| | - Kiyoaki Muto
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Sciences, Tohoku University, 468-1 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8572, Japan
| | - Ryutaro Orita
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Sciences, Tohoku University, 468-1 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8572, Japan
| | - Ayumu Takeuchi
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Sciences, Tohoku University, 468-1 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8572, Japan
| | - Yuka Kamachi
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Sciences, Tohoku University, 468-1 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8572, Japan
| | - Masahiro Hitosugi
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Sciences, Tohoku University, 468-1 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8572, Japan
| | - Akira Yoshimi
- Laboratory of Environmental Interface Technology of Filamentous Fungi, Graduate School of Agriculture, Kyoto University, Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan; ABE-Project, New Industry Creation Hatchery Center, Tohoku University, 6-6-10 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579, Japan
| | - Takahiro Shintani
- Laboratory of Bioindustrial Genomics, Department of Bioindustrial Informatics and Genomics, Graduate School of Agricultural Sciences, Tohoku University, 468-1 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8572, Japan
| | - Yoshikazu Kato
- Mixing Technology Laboratory, Satake Chemical Equipment Mfg., Ltd., 60 Niizo, Toda, Saitama 335-0021, Japan
| | - Keietsu Abe
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Sciences, Tohoku University, 468-1 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8572, Japan; ABE-Project, New Industry Creation Hatchery Center, Tohoku University, 6-6-10 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579, Japan; Department of Microbial Resources, Graduate School of Agricultural Science, Tohoku University, 468-1 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8572, Japan.
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20
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Mei L, Wang X, Yin Y, Tang G, Wang C. Conservative production of galactosaminogalactan in Metarhizium is responsible for appressorium mucilage production and topical infection of insect hosts. PLoS Pathog 2021; 17:e1009656. [PMID: 34125872 PMCID: PMC8224951 DOI: 10.1371/journal.ppat.1009656] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 06/24/2021] [Accepted: 05/20/2021] [Indexed: 02/07/2023] Open
Abstract
The exopolysaccharide galactosaminogalactan (GAG) has been well characterized in Aspergilli, especially the human pathogen Aspergillus fumigatus. It has been found that a five-gene cluster is responsible for GAG biosynthesis in Aspergilli to mediate fungal adherence, biofilm formation, immunosuppression or induction of host immune defences. Herein, we report the presence of the conserved GAG biosynthetic gene cluster in the insect pathogenic fungus Metarhizium robertsii to mediate either similar or unique biological functions. Deletion of the gene cluster disabled fungal ability to produce GAG on germ tubes, mycelia and appressoria. Relative to the wild type strain, null mutant was impaired in topical infection but not injection of insect hosts. We found that GAG production by Metarhizium is partially acetylated and could mediate fungal adherence to hydrophobic insect cuticles, biofilm formation, and penetration of insect cuticles. In particular, it was first confirmed that this exopolymer is responsible for the formation of appressorium mucilage, the essential extracellular matrix formed along with the infection structure differentiation to mediate cell attachment and expression of cuticle degrading enzymes. In contrast to its production during A. fumigatus invasive growth, GAG is not produced on the Metarhizium cells harvested from insect hemocoels; however, the polymer can glue germ tubes into aggregates to form mycelium pellets in liquid culture. The results of this study unravel the biosynthesis and unique function of GAG in a fungal system apart from the aspergilli species.
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Affiliation(s)
- Lijuan Mei
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
| | - Xuewen Wang
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
| | - Ying Yin
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Guirong Tang
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Chengshu Wang
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
- * E-mail:
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21
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Li Q, Zhu X, Xie Y, Zhong Y. o-Vanillin, a promising antifungal agent, inhibits Aspergillus flavus by disrupting the integrity of cell walls and cell membranes. Appl Microbiol Biotechnol 2021; 105:5147-5158. [PMID: 34086115 DOI: 10.1007/s00253-021-11371-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 05/06/2021] [Accepted: 05/26/2021] [Indexed: 11/25/2022]
Abstract
o-Vanillin is a natural product that has been widely applied in the food and pharmaceutical industries. In this study, we determined that o-vanillin can strongly inhibit the growth of Aspergillus flavus mycelia. However, the inhibition mechanism of o-vanillin is still elusive. The ultrastructural morphology of mycelia was injured, and the cell walls were destroyed. The OH functional groups on cell walls were altered, and the content of protein in mycelial cell walls was reduced by o-vanillin. The content of β-1,3-glucan in cell walls was significantly (P < 0.05) reduced by o-vanillin in a dose-dependent manner, while chitin was not markedly affected. Moreover, o-vanillin led to an increase in the permeability of cell membranes. o-Vanillin also exhibited a promising antifungal effect on contaminated corn kernels. Therefore, o-vanillin inhibited the growth of mycelia by disrupting the integrity of cell walls and cell membranes. This study not only sheds light on the antifungal mechanism of o-vanillin but also indicates that it is a promising agent for the control of A. flavus infection. KEY POINTS: • o-Vanillin has strong inhibitory effects on A. flavus. • o-Vanillin destroyed the integrity of cell walls and cell membranes. • o-Vanillin could effectively inhibit the growth of A. flavus on corn kernels.
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Affiliation(s)
- Qian Li
- Henan Key Laboratory of Cereal and Oil Food Safety Inspection and Control, College of Food Science and Engineering, Henan University of Technology, Zhengzhou, 450001, Henan, People's Republic of China
| | - Xiaoman Zhu
- Henan Key Laboratory of Cereal and Oil Food Safety Inspection and Control, College of Food Science and Engineering, Henan University of Technology, Zhengzhou, 450001, Henan, People's Republic of China
| | - Yanli Xie
- Henan Key Laboratory of Cereal and Oil Food Safety Inspection and Control, College of Food Science and Engineering, Henan University of Technology, Zhengzhou, 450001, Henan, People's Republic of China.
| | - Yue Zhong
- Henan Key Laboratory of Cereal and Oil Food Safety Inspection and Control, College of Food Science and Engineering, Henan University of Technology, Zhengzhou, 450001, Henan, People's Republic of China
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22
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Accelerated glucose metabolism in hyphae-dispersed Aspergillus oryzae is suitable for biological production. J Biosci Bioeng 2021; 132:140-147. [PMID: 33896702 DOI: 10.1016/j.jbiosc.2021.03.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 03/28/2021] [Accepted: 03/28/2021] [Indexed: 11/23/2022]
Abstract
Recently, a hyphae-dispersed type of filamentous fungus Aspergillus oryzae was constructed via genetic engineering, and industrial applications are expected due to the ease of handling and to the level of protein production properties. In this study, we constructed cellulase-expressing strains using wild-type and hyphae-dispersed strains to investigate the correlation between protein productivity and metabolism. Compared with the original strain, the hyphae-dispersed cellulase-expressing strain showed elevated cellulase activity, rapid glucose consumption, increased mycelial dry weight, an increased expression of cellulase genes, and activated respiration activity. Comparative metabolomic analysis showed fewer metabolites in the glycolysis and TCA cycles in the dispersed strains than in the original strains. These results indicate that the flux of carbohydrate metabolism in the hyphae-dispersed strains is smoother than that in the original strains. Such efficient metabolic flux would contribute to efficient energy conversion and to sufficient energy supply to anabolisms, such as mycelial growth and protein production. Our findings suggest that the hyphae-dispersed strains could be a useful host not only for protein production but also for the biological production of various chemicals such as organic acids.
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23
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Pascual S, Planas A. Carbohydrate de-N-acetylases acting on structural polysaccharides and glycoconjugates. Curr Opin Chem Biol 2020; 61:9-18. [PMID: 33075728 DOI: 10.1016/j.cbpa.2020.09.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/06/2020] [Accepted: 09/08/2020] [Indexed: 12/14/2022]
Abstract
Deacetylation of N-acetylhexosamine residues in structural polysaccharides and glycoconjugates is catalyzed by different families of carbohydrate esterases that, despite different structural folds, share a common metal-assisted acid/base mechanism with the metal cation coordinated with a conserved Asp-His-His triad. These enzymes serve diverse biological functions in the modification of cell-surface polysaccharides in bacteria and fungi as well as in the metabolism of hexosamines in the biosynthesis of cellular glycoconjugates. Focusing on carbohydrate de-N-acetylases, this article summarizes the background of the different families from a structural and functional viewpoint and covers advances in the characterization of novel enzymes over the last 2-3 years. Current research is addressed to the identification of new deacetylases and unravel their biological functions as they are candidate targets for the design of antimicrobials against pathogenic bacteria and fungi. Likewise, some families are also used as biocatalysts for the production of defined glycostructures with diverse applications.
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Affiliation(s)
- Sergi Pascual
- Laboratory of Biochemistry, Institut Químic de Sarrià, University Ramon Llull, 08017, Barcelona, Spain
| | - Antoni Planas
- Laboratory of Biochemistry, Institut Químic de Sarrià, University Ramon Llull, 08017, Barcelona, Spain.
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24
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Takeshita N. Fungal research in Japan: tradition and future. Fungal Biol Biotechnol 2020; 7:14. [PMID: 32974037 PMCID: PMC7507618 DOI: 10.1186/s40694-020-00104-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 05/09/2020] [Indexed: 11/10/2022] Open
Affiliation(s)
- Norio Takeshita
- Microbiology Research Center for Sustainability (MiCS), Faculty of Life and Environmental Sciences, University of Tsukuba, Tokyo, Japan
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25
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Miyazawa K, Yoshimi A, Abe K. The mechanisms of hyphal pellet formation mediated by polysaccharides, α-1,3-glucan and galactosaminogalactan, in Aspergillus species. Fungal Biol Biotechnol 2020; 7:10. [PMID: 32626592 PMCID: PMC7329490 DOI: 10.1186/s40694-020-00101-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 06/12/2020] [Indexed: 01/01/2023] Open
Abstract
Filamentous fungi are widely used for production of enzymes and chemicals, and are industrially cultivated both in liquid and solid cultures. Submerged culture is often used as liquid culture for filamentous fungi. In submerged culture, filamentous fungi show diverse macromorphology such as hyphal pellets and dispersed hyphae depending on culture conditions and genetic backgrounds of fungal strains. Although the macromorphology greatly affects the productivity of submerged cultures, the specific cellular components needed for hyphal aggregation after conidial germination have not been characterized. Recently we reported that the primary cell wall polysaccharide α-1,3-glucan and the extracellular polysaccharide galactosaminogalactan (GAG) contribute to hyphal aggregation in Aspergillus oryzae, and that a strain deficient in both α-1,3-glucan and GAG shows dispersed hyphae in liquid culture. In this review, we summarize our current understanding of the contribution of chemical properties of α-1,3-glucan and GAG to hyphal aggregation. Various ascomycetes and basidiomycetes have α-1,3-glucan synthase gene(s). In addition, some Pezizomycotina fungi, including species used in the fermentation industry, also have GAG biosynthetic genes. We also review here the known mechanisms of biosynthesis of α-1,3-glucan and GAG. Regulation of the biosynthesis of the two polysaccharides could be a potential way of controlling formation of hyphal pellets.
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Affiliation(s)
- Ken Miyazawa
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki-Aoba, Aoba-ku, Sendai, 980-8572 Japan
| | - Akira Yoshimi
- Laboratory of Environmental Interface Technology of Filamentous Fungi, Graduate School of Agriculture, Kyoto University, Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto, 606-8502 Japan.,ABE-project, New Industry Creation Hatchery Center, Tohoku University, 6-6-10 Aramaki-Aoba, Aoba-ku, Sendai, 980-8579 Japan
| | - Keietsu Abe
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki-Aoba, Aoba-ku, Sendai, 980-8572 Japan.,ABE-project, New Industry Creation Hatchery Center, Tohoku University, 6-6-10 Aramaki-Aoba, Aoba-ku, Sendai, 980-8579 Japan.,Laboratory of Microbial Resources, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki-Aoba, Aoba-ku, Sendai, 980-8572 Japan
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26
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Structural and biochemical characterization of the exopolysaccharide deacetylase Agd3 required for Aspergillus fumigatus biofilm formation. Nat Commun 2020; 11:2450. [PMID: 32415073 PMCID: PMC7229062 DOI: 10.1038/s41467-020-16144-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 04/16/2020] [Indexed: 01/14/2023] Open
Abstract
The exopolysaccharide galactosaminogalactan (GAG) is an important virulence factor of the fungal pathogen Aspergillus fumigatus. Deletion of a gene encoding a putative deacetylase, Agd3, leads to defects in GAG deacetylation, biofilm formation, and virulence. Here, we show that Agd3 deacetylates GAG in a metal-dependent manner, and is the founding member of carbohydrate esterase family CE18. The active site is formed by four catalytic motifs that are essential for activity. The structure of Agd3 includes an elongated substrate-binding cleft formed by a carbohydrate binding module (CBM) that is the founding member of CBM family 87. Agd3 homologues are encoded in previously unidentified putative bacterial exopolysaccharide biosynthetic operons and in other fungal genomes.
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