1
|
Li C, Yang S, Zhang M, Yang Y, Li Z, Peng L. SntB Affects Growth to Regulate Infecting Potential in Penicillium italicum. J Fungi (Basel) 2024; 10:368. [PMID: 38921355 PMCID: PMC11204802 DOI: 10.3390/jof10060368] [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: 04/22/2024] [Revised: 05/15/2024] [Accepted: 05/18/2024] [Indexed: 06/27/2024] Open
Abstract
Penicillium italicum, a major postharvest pathogen, causes blue mold rot in citrus fruits through the deployment of various virulence factors. Recent studies highlight the role of the epigenetic reader, SntB, in modulating the pathogenicity of phytopathogenic fungi. Our research revealed that the deletion of the SntB gene in P. italicum led to significant phenotypic alterations, including delayed mycelial growth, reduced spore production, and decreased utilization of sucrose. Additionally, the mutant strain exhibited increased sensitivity to pH fluctuations and elevated iron and calcium ion stress, culminating in reduced virulence on Gannan Novel oranges. Ultrastructural analyses disclosed notable disruptions in cell membrane integrity, disorganization within the cellular matrix, and signs of autophagy. Transcriptomic data further indicated a pronounced upregulation of hydrolytic enzymes, oxidoreductases, and transport proteins, suggesting a heightened energy demand. The observed phenomena were consistent with a carbon starvation response potentially triggering apoptotic pathways, including iron-dependent cell death. These findings collectively underscored the pivotal role of SntB in maintaining the pathogenic traits of P. italicum, proposing that targeting PiSntB could offer a new avenue for controlling citrus fungal infections and subsequent fruit decay.
Collapse
Affiliation(s)
| | | | | | | | | | - Litao Peng
- College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; (C.L.); (S.Y.)
| |
Collapse
|
2
|
Jin J, Diao Y, Xiong X, Yu C, Tian Y, Li C, Liu H. The Regulation of the Growth and Pathogenicity of Valsa mali by the Carbon Metabolism Repressor CreA. Int J Mol Sci 2023; 24:ijms24119252. [PMID: 37298203 DOI: 10.3390/ijms24119252] [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: 03/13/2023] [Revised: 05/18/2023] [Accepted: 05/18/2023] [Indexed: 06/12/2023] Open
Abstract
Carbon catabolite repression (CCR) is a very important mechanism for efficient use of carbon sources in the environment and is necessary for the regulation of fungal growth, development, and pathogenesis. Although there have been extensive studies conducted regarding this mechanism in fungi, little is yet known about the effects of CreA genes on Valsa mali. However, based on the results obtained in this study for the identification of the VmCreA gene in V. mali, it was determined that the gene was expressed at all stages of fungal growth, with self-repression observed at the transcriptional level. Furthermore, the functional analysis results of the gene deletion mutants (ΔVmCreA) and complements (CTΔVmCreA) showed that the VmCreA gene played an important role in the growth, development, pathogenicity, and carbon source utilization of V. mali.
Collapse
Affiliation(s)
- Jiyang Jin
- Mountain Tai Forest Ecosystem Research Station of State Forestry Administration, Key Laboratory of Ecological Protection and Safety Prevention of the Lower Yellow River, Forestry College, Shandong Agricultural University, Tai'an 271018, China
| | - Yufei Diao
- Shandong Research Center for Forestry Harmful Biological Control Engineering and Technology, College of Plant Protection, Shandong Agricultural University, Tai'an 271018, China
| | - Xiong Xiong
- Mountain Tai Forest Ecosystem Research Station of State Forestry Administration, Key Laboratory of Ecological Protection and Safety Prevention of the Lower Yellow River, Forestry College, Shandong Agricultural University, Tai'an 271018, China
| | - Chengming Yu
- Shandong Research Center for Forestry Harmful Biological Control Engineering and Technology, College of Plant Protection, Shandong Agricultural University, Tai'an 271018, China
| | - Yehan Tian
- Shandong Research Center for Forestry Harmful Biological Control Engineering and Technology, College of Plant Protection, Shandong Agricultural University, Tai'an 271018, China
| | - Chuanrong Li
- Mountain Tai Forest Ecosystem Research Station of State Forestry Administration, Key Laboratory of Ecological Protection and Safety Prevention of the Lower Yellow River, Forestry College, Shandong Agricultural University, Tai'an 271018, China
| | - Huixiang Liu
- Shandong Research Center for Forestry Harmful Biological Control Engineering and Technology, College of Plant Protection, Shandong Agricultural University, Tai'an 271018, China
| |
Collapse
|
3
|
Effect of Water Activity on Conidia Germination in Aspergillus flavus. Microorganisms 2022; 10:microorganisms10091744. [PMID: 36144346 PMCID: PMC9504883 DOI: 10.3390/microorganisms10091744] [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: 07/25/2022] [Revised: 08/18/2022] [Accepted: 08/24/2022] [Indexed: 11/16/2022] Open
Abstract
In this study, we explored the mechanism underlying Aspergillus flavus conidia germination inhibited by decreased water activity. The impact of low water activity was analyzed at 4 h, 8 h and 12 h. Additionally, we demonstrated that low water activity affected cell shape and decreased cell sizes. Transcriptomics found numerous differentially expressed genes (DEGs) during the first 12 h of germination, with 654 DEGs observed among 4 h, 8 h and 12 h. In particular, more DEGs were detected at 8 h of germinating. Therefore, proteomics was performed at 8 h, and 209 differentially expressed proteins (DEPs) were speculated, with 94 up-regulated and 115 down-regulated. Combined analysis of KEGG of transcriptomics and proteomics demonstrated that the dominant pathways were nutrient metabolism and translation. We also found several DEGs and DEPs in the Mitogen Activated Protein Kinase (MAPK) pathway. Therefore, we concluded that low water activity inhibited conidia germination, causing unregular morphology. In addition, low water activity influenced expression of creA, TreB in carbohydrate metabolism, Clr4, RmtA in amino acid metabolism and RPL37, RPL3 in translation in Aspergillus flavus.
Collapse
|
4
|
Transcriptional Stages of Conidia Germination and Associated Genes in Aspergillus flavus: An Essential Role for Redox Genes. Toxins (Basel) 2022; 14:toxins14080560. [PMID: 36006223 PMCID: PMC9412981 DOI: 10.3390/toxins14080560] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 08/04/2022] [Accepted: 08/12/2022] [Indexed: 12/03/2022] Open
Abstract
Aflatoxin is a threatening mycotoxin primarily present in the agricultural environment, especially in food and feedstuff, and poses significant global health risks. Aflatoxins are produced mainly by Aspergillus flavus. Conidia germination is the first step for A. flavus development. In this study, the transcriptome of A. flavus conidia was analyzed at three different stages of conidia germination, which were characterized by two different microscopes. Dormant conidia grew isotropically with the cell size increasing up to 5 h of after being inoculated in a liquid medium. Conidia changed towards polarized growth from 5 to 10 h of germination, during which germ tubes formed. Moreover, transcriptome analyses revealed that a larger number of genes changed in the isotropic growth stages compared to polarized growth, with 1910 differentially expressed genes (DEGs) up-regulated and 969 DEGs down-regulated in isotropic growth. GO and KEGG pathway analyses and pathway enrichment demonstrated that, in the isotropic growth stage, the top three pathways were translation, amino acid and carbohydrate metabolism. The ribosome was a key pathway in translation, as RPS28e, RPL53 and RPL36e were the top three DEGs. For polarized growth stage, lipid metabolism, amino acid metabolism and carbohydrate metabolism were the top three most active pathways. POX1 from alpha-linolenic acid metabolism was a DEG in lipid metabolism as well. Genes related to the antioxidant system were crucial for conidia germination. Furthermore, RT-PCR results showed the same trends as the transcriptome for redox genes, and essential oils have a significant inhibitory effect on germination rate and redox gene expression. Therefore, redox genes play an important role during germination, and the disruption of redox genes is involved in the mechanism of action of coumalic acid and geraniol against A. flavus spore germination.
Collapse
|
5
|
Ma X, Jiang Y, Ma L, Luo S, Du H, Li X, Xing F. Corepressors SsnF and RcoA Regulate Development and Aflatoxin B1 Biosynthesis in Aspergillus flavus NRRL 3357. Toxins (Basel) 2022; 14:toxins14030174. [PMID: 35324671 PMCID: PMC8954095 DOI: 10.3390/toxins14030174] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2021] [Revised: 02/18/2022] [Accepted: 02/21/2022] [Indexed: 02/04/2023] Open
Abstract
Aspergillus flavus is a saprophytic fungus that can be found across the entire world. It can produce aflatoxin B1 (AFB1), which threatens human health. CreA, as the central factor in carbon catabolite repression (CCR), regulates carbon catabolism and AFB1 biosynthesis in A. flavus. Additionally, SsnF-RcoA are recognized as the corepressors of CreA in CCR. In this study, ssnF and rcoA not only regulated the expressions of CCR factors and hydrolase genes, but also positively affected mycelia growth, conidia production, sclerotia formation, and osmotic stress response in A. flavus. More importantly, SsnF and RcoA were identified as positive regulators for AFB1 biosynthesis, as they modulate the AF cluster genes and the relevant regulators at a transcriptional level. Additionally, the interactions of SsnF-CreA and RcoA-CreA were strong and moderate, respectively. However, the interaction of SsnF and RcoA was weak. The interaction models of CreA-SsnF, CreA-RcoA, and SsnF-RcoA were also simulated with a docking analysis. All things considered, SsnF and RcoA are not just the critical regulators of the CCR pathway, but the global regulators involving in morphological development and AFB1 biosynthesis in A. flavus.
Collapse
Affiliation(s)
| | | | | | | | | | - Xu Li
- Correspondence: (X.L.); (F.X.)
| | | |
Collapse
|
6
|
Gila BC, Antal K, Birkó Z, Keserű JS, Pócsi I, Emri T. Strategies Shaping the Transcription of Carbohydrate-Active Enzyme Genes in Aspergillus nidulans. J Fungi (Basel) 2022; 8:jof8010079. [PMID: 35050018 PMCID: PMC8780418 DOI: 10.3390/jof8010079] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Revised: 01/07/2022] [Accepted: 01/10/2022] [Indexed: 12/16/2022] Open
Abstract
Understanding the coordinated regulation of the hundreds of carbohydrate-active enzyme (CAZyme) genes occurring in the genomes of fungi has great practical importance. We recorded genome-wide transcriptional changes of Aspergillus nidulans cultivated on glucose, lactose, or arabinogalactan, as well as under carbon-starved conditions. We determined both carbon-stress-specific changes (weak or no carbon source vs. glucose) and carbon-source-specific changes (one type of culture vs. all other cultures). Many CAZyme genes showed carbon-stress-specific and/or carbon-source-specific upregulation on arabinogalactan (138 and 62 genes, respectively). Besides galactosidase and arabinan-degrading enzyme genes, enrichment of cellulolytic, pectinolytic, mannan, and xylan-degrading enzyme genes was observed. Fewer upregulated genes, 81 and 107 carbon stress specific, and 6 and 16 carbon source specific, were found on lactose and in carbon-starved cultures, respectively. They were enriched only in galactosidase and xylosidase genes on lactose and rhamnogalacturonanase genes in both cultures. Some CAZyme genes (29 genes) showed carbon-source-specific upregulation on glucose, and they were enriched in β-1,4-glucanase genes. The behavioral ecological background of these characteristics was evaluated to comprehensively organize our knowledge on CAZyme production, which can lead to developing new strategies to produce enzymes for plant cell wall saccharification.
Collapse
Affiliation(s)
- Barnabás Cs. Gila
- Department of Molecular Biotechnology and Microbiology, Faculty of Sciences and Technology, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary; (B.C.G.); (I.P.)
- Doctoral School of Nutrition and Food Sciences, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
| | - Károly Antal
- Department of Zoology, Eszterházy Károly Catholic University, Eszterházy tér 1, 3300 Eger, Hungary;
| | - Zsuzsanna Birkó
- Department of Human Genetics, Faculty of Medicine, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary; (Z.B.); (J.S.K.)
| | - Judit Sz. Keserű
- Department of Human Genetics, Faculty of Medicine, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary; (Z.B.); (J.S.K.)
| | - István Pócsi
- Department of Molecular Biotechnology and Microbiology, Faculty of Sciences and Technology, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary; (B.C.G.); (I.P.)
| | - Tamás Emri
- Department of Molecular Biotechnology and Microbiology, Faculty of Sciences and Technology, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary; (B.C.G.); (I.P.)
- Correspondence:
| |
Collapse
|
7
|
Boczonádi I, Jakab Á, Baranyai E, Tóth CN, Daróczi L, Csernoch L, Kis G, Antal M, Pusztahelyi T, Grawunder A, Merten D, Emri T, Fábián I, Kothe E, Pócsi I. Rare earth element sequestration by Aspergillus oryzae biomass. ENVIRONMENTAL TECHNOLOGY 2021; 42:3725-3735. [PMID: 32134365 DOI: 10.1080/09593330.2020.1739146] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 03/02/2020] [Indexed: 06/10/2023]
Abstract
The fungus Aspergillus oryzae could be shown to be a viable alternative for biosorption of valuable metals from solution. Fungal biomass can be obtained easily in high quantities as a waste of biofermentation processes, and used in a complex, multi-phase solution mimicking naturally occurring, mining-affected water samples. With test solution formulated after natural conditions, formation of secondary Al and Fe phases co-precipitating Ce was recorded in addition to specific biosorption of rare earth elements. Remarkably, the latter were removed from the solution despite the presence of high concentrations of interfering Fe and Al. The biomass was viable even after prolonged incubation in the metal solution, and minimal inhibitory concentrations for single metals were higher than those in the test solution. While precipitation/biosorption of Ce (maximal biosorption efficiency was 58.0 ± 22.3% after 6 h of incubation) coincided with the gross removal of Fe from the metal solution, Y (81.5 ± 11.3% efficiency, 24 h incubation) and Nd (87.4 ± 9.1% efficiency, 24 h incubation) were sequestered later, similarly to Ni and Zn. The biphasic binding pattern specific to single metals could be connected to dynamically changing pH and NH4+ concentrations, which were attributed to the physiological changes taking place in starving A. oryzae biomass. The metals were found extracellularly in minerals associated with the cell wall, and intracellularly precipitated in the vacuoles. The latter process was explained with intracellular metal detoxification resulting in metal resistance.
Collapse
Affiliation(s)
- Imre Boczonádi
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
- Juhász-Nagy Pál Doctoral School, University of Debrecen, Debrecen, Hungary
| | - Ágnes Jakab
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Edina Baranyai
- Department of Inorganic and Analytical Chemistry, Agilent Atomic Spectroscopy Partner Laboratory, University of Debrecen, Debrecen, Hungary
| | - Csilla Noémi Tóth
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Debrecen, Hungary
| | - Lajos Daróczi
- Department of Solid State Physics, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - László Csernoch
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Gréta Kis
- Department of Anatomy, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Miklós Antal
- Department of Anatomy, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Tünde Pusztahelyi
- Central Laboratory of Agricultural and Food Products, Faculty of Agricultural and Food Sciences and Environmental Management, University of Debrecen, Debrecen, Hungary
| | - Anja Grawunder
- Institute of Geosciences, Faculty of Chemistry and Earth Sciences, Friedrich Schiller University, Jena, Germany
| | - Dirk Merten
- Institute of Geosciences, Faculty of Chemistry and Earth Sciences, Friedrich Schiller University, Jena, Germany
| | - Tamás Emri
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - István Fábián
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Debrecen, Hungary
- MTA-DE Redox and Homogeneous Catalytic Reaction Mechanisms Research Group
| | - Erika Kothe
- Institute of Microbiology, Faculty for Bioscience, Friedrich Schiller University, Jena, Germany
| | - István Pócsi
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| |
Collapse
|
8
|
Emri T, Gila B, Antal K, Fekete F, Moon H, Yu JH, Pócsi I. AtfA-Independent Adaptation to the Toxic Heavy Metal Cadmium in Aspergillus nidulans. Microorganisms 2021; 9:microorganisms9071433. [PMID: 34361869 PMCID: PMC8307709 DOI: 10.3390/microorganisms9071433] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 06/28/2021] [Accepted: 06/30/2021] [Indexed: 12/13/2022] Open
Abstract
Cadmium is an exceptionally toxic industrial and environmental pollutant classified as a human carcinogen. In order to provide insight into how we can keep our environment safe from cadmium contamination and prevent the accumulation of it in the food chain, we aim to elucidate how Aspergillus nidulans, one of the most abundant fungi in soil, survives and handles cadmium stress. As AtfA is the main transcription factor governing stress responses in A. nidulans, we examined genome-wide expression responses of wild-type and the atfA null mutant exposed to CdCl2. Both strains showed up-regulation of the crpA Cu2+/Cd2+ pump gene and AN7729 predicted to encode a putative bis(glutathionato)-cadmium transporter, and transcriptional changes associated with elevated intracellular Cys availability leading to the efficient adaptation to Cd2+. Although the deletion of atfA did not alter the cadmium tolerance of the fungus, the cadmium stress response of the mutant differed from that of a reference strain. Promoter and transcriptional analyses of the “Phospho-relay response regulator” genes suggest that the AtfA-dependent regulation of these genes can be relevant in this phenomenon. We concluded that the regulatory network of A. nidulans has a high flexibility allowing the fungus to adapt efficiently to stress both in the presence and absence of this important transcription factor.
Collapse
Affiliation(s)
- Tamás Emri
- Department of Molecular Biotechnology and Microbiology, Faculty of Sciences and Technology, University of Debrecen, 4032 Debrecen, Hungary; (B.G.); (F.F.); (I.P.)
- Correspondence:
| | - Barnabás Gila
- Department of Molecular Biotechnology and Microbiology, Faculty of Sciences and Technology, University of Debrecen, 4032 Debrecen, Hungary; (B.G.); (F.F.); (I.P.)
- Doctoral School of Nutrition and Food Sciences, University of Debrecen, 4032 Debrecen, Hungary
| | - Károly Antal
- Department of Zoology, Eszterházy Károly University, 3300 Eger, Hungary;
| | - Fanni Fekete
- Department of Molecular Biotechnology and Microbiology, Faculty of Sciences and Technology, University of Debrecen, 4032 Debrecen, Hungary; (B.G.); (F.F.); (I.P.)
| | - Heungyun Moon
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA; (H.M.); (J.-H.Y.)
| | - Jae-Hyuk Yu
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA; (H.M.); (J.-H.Y.)
- Department of Systems Biotechnology, Konkuk University, Seoul 05029, Korea
| | - István Pócsi
- Department of Molecular Biotechnology and Microbiology, Faculty of Sciences and Technology, University of Debrecen, 4032 Debrecen, Hungary; (B.G.); (F.F.); (I.P.)
| |
Collapse
|
9
|
Archer M, Xu J. Current Practices for Reference Gene Selection in RT-qPCR of Aspergillus: Outlook and Recommendations for the Future. Genes (Basel) 2021; 12:genes12070960. [PMID: 34202507 PMCID: PMC8307107 DOI: 10.3390/genes12070960] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 06/20/2021] [Accepted: 06/21/2021] [Indexed: 12/21/2022] Open
Abstract
Aspergillus is a genus of filamentous fungi with vast geographic and ecological distributions. Species within this genus are clinically, agriculturally and biotechnologically relevant, leading to increasing interest in elucidating gene expression dynamics of key metabolic and physiological processes. Reverse-transcription quantitative Polymerase Chain Reaction (RT-qPCR) is a sensitive and specific method of quantifying gene expression. A crucial step for comparing RT-qPCR results between strains and experimental conditions is normalisation to experimentally validated reference gene(s). In this review, we provide a critical analysis of current reference gene selection and validation practices for RT-qPCR gene expression analyses of Aspergillus. Of 90 primary research articles obtained through our PubMed query, 17 experimentally validated the reference gene(s) used. Twenty reference genes were used across the 90 studies, with beta-tubulin being the most used reference gene, followed by actin, 18S rRNA and glyceraldehyde 3-phosphate dehydrogenase. Sixteen of the 90 studies used multiple reference genes for normalisation. Failing to experimentally validate the stability of reference genes can lead to conflicting results, as was the case for four studies. Overall, our review highlights the need to experimentally validate reference genes in RT-qPCR studies of Aspergillus.
Collapse
Affiliation(s)
| | - Jianping Xu
- Correspondence: ; Tel.: +1-905-525-9140 (ext. 27934); Fax: +1-905-522-6066
| |
Collapse
|
10
|
Lima DMCG, Costa TPC, Emri T, Pócsi I, Pupin B, Rangel DEN. Fungal tolerance to Congo red, a cell wall integrity stress, as a promising indicator of ecological niche. Fungal Biol 2021; 125:646-657. [PMID: 34281658 DOI: 10.1016/j.funbio.2021.03.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 03/27/2021] [Accepted: 03/31/2021] [Indexed: 02/06/2023]
Abstract
Differential sensitivities to the cell wall stress caused by Congo red (CR) have been observed in many fungal species. In this study, the tolerances and sensitivities to CR was studied with an assorted collection of fungal species from three phylogenetic classes: Sordariomycetes, Dothideomycetes, and Eurotiomycetes, three orders, and eight families. These grouped into different ecological niches, such as insect pathogens, plant pathogens, saprotrophs, and mycoparasitics. The saprotroph Aspergillus niger and the mycoparasite Trichoderma atroviride stood out as the most resistant species to cell wall stress caused by CR, followed by the plant pathogenic fungi, a mycoparasite, and other saprotrophs. The insect pathogens had low tolerance to CR. The insect pathogens Metarhizium acridum and Cordyceps fumosorosea were the most sensitive to CR. In conclusion, Congo red tolerance may reflect ecological niche, accordingly, the tolerances of the fungal species to Congo red were closely aligned with their ecology.
Collapse
Affiliation(s)
| | | | - Tamás Emri
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - István Pócsi
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Breno Pupin
- Centro de Ciência do Sistema Terrestre, Instituto Nacional de Pesquisa Especiais - INPE, São José dos Campos, SP, Brazil
| | | |
Collapse
|
11
|
The DUG Pathway Governs Degradation of Intracellular Glutathione in Aspergillus nidulans. Appl Environ Microbiol 2021; 87:AEM.01321-20. [PMID: 33637571 DOI: 10.1128/aem.01321-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 02/10/2021] [Indexed: 12/27/2022] Open
Abstract
Glutathione (GSH) is an abundant tripeptide that plays a crucial role in shielding cellular macromolecules from various reactive oxygen and nitrogen species in fungi. Understanding GSH metabolism is of vital importance for deciphering redox regulation in these microorganisms. In the present study, to better understand the GSH metabolism in filamentous fungi, we investigated functions of the dugB and dugC genes in the model fungus Aspergillus nidulans These genes are orthologues of dug2 and dug3, which are involved in cytosolic GSH degradation in Saccharomyces cerevisiae The deletion of dugB, dugC, or both resulted in a moderate increase in the GSH content in mycelia grown on glucose, reduced conidium production, and disturbed sexual development. In agreement with these observations, transcriptome data showed that genes encoding mitogen-activated protein (MAP) kinase pathway elements (e.g., steC, sskB, hogA, and mkkA) or regulatory proteins of conidiogenesis and sexual differentiation (e.g., flbA, flbC, flbE, nosA, rosA, nsdC, and nsdD) were downregulated in the ΔdugB ΔdugC mutant. Deletion of dugB and/or dugC slowed the depletion of GSH pools during carbon starvation. It also reduced accumulation of reactive oxygen species and decreased autolytic cell wall degradation and enzyme secretion but increased sterigmatocystin formation. Transcriptome data demonstrated that enzyme secretions-in contrast to mycotoxin production-were controlled at the posttranscriptional level. We suggest that GSH connects starvation and redox regulation to each other: cells utilize GSH as a stored carbon source during starvation. The reduction of GSH content alters the redox state, activating regulatory pathways responsible for carbon starvation stress responses.IMPORTANCE Glutathione (GSH) is a widely distributed tripeptide in both eukaryotes and prokaryotes. Owing to its very low redox potential, antioxidative character, and high intracellular concentration, GSH profoundly shapes the redox status of cells. Our observations suggest that GSH metabolism and/or the redox status of cells plays a determinative role in several important aspects of fungal life, including oxidative stress defense, protein secretion, and secondary metabolite production (including mycotoxin formation), as well as sexual and asexual differentiations. We demonstrated that even a slightly elevated GSH level can substantially disturb the homeostasis of fungi. This information could be important for development of new GSH-producing strains or for any biotechnologically relevant processes where the GSH content, antioxidant capacity, or oxidative stress tolerance of a fungal strain is manipulated.
Collapse
|
12
|
Carbon Catabolite Repression Gene AoCreA Regulates Morphological Development and Ochratoxin A Biosynthesis Responding to Carbon Sources in Aspergillus ochraceus. Toxins (Basel) 2020; 12:toxins12110697. [PMID: 33152993 PMCID: PMC7693787 DOI: 10.3390/toxins12110697] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 10/23/2020] [Accepted: 10/25/2020] [Indexed: 11/16/2022] Open
Abstract
Carbon is one of the most important nutrients for the development and secondary metabolism in fungi. CreA is the major transcriptional factor mediating carbon catabolite repression, which is employed in the utilization of carbon sources. Aspergillus ochraceus contaminates various food and feed containing different carbon sources by producing ochratoxin A (OTA). However, little is known about the function of AoCreA in regulating the morphology and OTA production of A. ochraceus. To give an insight into the mechanism of the carbon sources regulating development of A. ochraceus and OTA production, we have identified AoCreA in A. ochraceus. The homologous recombination strategy was used to generate the AoCreA deletion mutant (ΔAoCreA). We have investigated the morphology and OTA production of the wild type (WT) and ΔAoCreA of A. ochraceus with media containing different carbon sources (glucose, fructose, maltose, D-xylose, D-mannose, acetate, D-galactose, D-mannitol and lactose). ΔAoCreA showed a significant growth and conidiation defect on all media as compared with WT. Glucose and maltose were the most inducing media for OTA production by A. ochraceus, followed by sucrose and the nutrient-rich Yeast Extract Sucrose (YES) and Potato Dextrose Agar (PDA). The deletion of AoCreA led to a drastic reduction of OTA production on all kinds of media except PDA, which was supported by the expression profile of OTA biosynthetic genes. Furthermore, infection studies of ΔAoCreA on oats and pears showed the involvement of AoCreA in the pathogenicity of A. ochraceus. Thus, these results suggest that AoCreA regulates morphological development and OTA biosynthesis in response to carbon sources in A. ochraceus.
Collapse
|
13
|
Quemener M, Mara P, Schubotz F, Beaudoin D, Li W, Pachiadaki M, Sehein TR, Sylvan JB, Li J, Barbier G, Edgcomb V, Burgaud G. Meta-omics highlights the diversity, activity and adaptations of fungi in deep oceanic crust. Environ Microbiol 2020; 22:3950-3967. [PMID: 32743889 DOI: 10.1111/1462-2920.15181] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 07/23/2020] [Accepted: 07/31/2020] [Indexed: 02/03/2023]
Abstract
The lithified oceanic crust, lower crust gabbros in particular, has remained largely unexplored by microbiologists. Recently, evidence for heterogeneously distributed viable and transcriptionally active autotrophic and heterotrophic microbial populations within low-biomass communities was found down to 750 m below the seafloor at the Atlantis Bank Gabbro Massif, Indian Ocean. Here, we report on the diversity, activity and adaptations of fungal communities in the deep oceanic crust from ~10 to 780 mbsf by combining metabarcoding analyses with mid/high-throughput culturing approaches. Metabarcoding along with culturing indicate a low diversity of viable fungi, mostly affiliated to ubiquitous (terrestrial and aquatic environments) taxa. Ecophysiological analyses coupled with metatranscriptomics point to viable and transcriptionally active fungal populations engaged in cell division, translation, protein modifications and other vital cellular processes. Transcript data suggest possible adaptations for surviving in the nutrient-poor, lithified deep biosphere that include the recycling of organic matter. These active communities appear strongly influenced by the presence of cracks and veins in the rocks where fluids and resulting rock alteration create micro-niches.
Collapse
Affiliation(s)
- Maxence Quemener
- Université de Brest, EA 3882 Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, Technopôle Brest-Iroise, Plouzané, France
| | - Paraskevi Mara
- Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, USA.,Department of Biology, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, USA
| | - Florence Schubotz
- MARUM-Center for Marine Environmental Sciences, University Bremen, Leobener Strasse 8, Bremen, 28359, Germany
| | - David Beaudoin
- Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, USA.,Department of Biology, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, USA
| | - Wei Li
- College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Maria Pachiadaki
- Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, USA.,Department of Biology, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, USA
| | - Taylor R Sehein
- Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, USA.,Department of Biology, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, USA
| | - Jason B Sylvan
- Department of Oceanography, Texas A&M University, College Station, TX, 77845, USA
| | - Jiangtao Li
- State Key Laboratory of Marine Geology, Tongji University, Shanghai, 200092, China
| | - Georges Barbier
- Université de Brest, EA 3882 Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, Technopôle Brest-Iroise, Plouzané, France
| | - Virginia Edgcomb
- Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, USA.,Department of Biology, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, USA
| | - Gaëtan Burgaud
- Université de Brest, EA 3882 Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, Technopôle Brest-Iroise, Plouzané, France
| |
Collapse
|
14
|
Pang KL, Chiang MWL, Guo SY, Shih CY, Dahms HU, Hwang JS, Cha HJ. Growth study under combined effects of temperature, pH and salinity and transcriptome analysis revealed adaptations of Aspergillus terreus NTOU4989 to the extreme conditions at Kueishan Island Hydrothermal Vent Field, Taiwan. PLoS One 2020; 15:e0233621. [PMID: 32453769 PMCID: PMC7250430 DOI: 10.1371/journal.pone.0233621] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 05/08/2020] [Indexed: 12/03/2022] Open
Abstract
A high diversity of fungi was discovered on various substrates collected at the marine shallow-water Kueishan Island Hydrothermal Vent Field, Taiwan, using culture and metabarcoding methods but whether these fungi can grow and play an active role in such an extreme environment is unknown. We investigated the combined effects of different salinity, temperature and pH on growth of ten fungi (in the genera Aspergillus, Penicillium, Fodinomyces, Microascus, Trichoderma, Verticillium) isolated from the sediment and the vent crab Xenograpsus testudinatus. The growth responses of the tested fungi could be referred to three groups: (1) wide pH, salinity and temperature ranges, (2) salinity-dependent and temperature-sensitive, and (3) temperature-tolerant. Aspergillus terreus NTOU4989 was the only fungus which showed growth at 45 °C, pH 3 and 30 ‰ salinity, and might be active near the vents. We also carried out a transcriptome analysis to understand the molecular adaptations of A. terreus NTOU4989 under these extreme conditions. Data revealed that stress-related genes were differentially expressed at high temperature (45 °C); for instance, mannitol biosynthetic genes were up-regulated while glutathione S-transferase and amino acid oxidase genes down-regulated in response to high temperature. On the other hand, hydrogen ion transmembrane transport genes and phenylalanine ammonia lyase were up-regulated while pH-response transcription factor was down-regulated at pH 3, a relative acidic environment. However, genes related to salt tolerance, such as glycerol lipid metabolism and mitogen-activated protein kinase, were up-regulated in both conditions, possibly related to maintaining water homeostasis. The results of this study revealed the genetic evidence of adaptation in A. terreus NTOU4989 to changes of environmental conditions.
Collapse
Affiliation(s)
- Ka-Lai Pang
- Institute of Marine Biology and Centre of Excellence for the Oceans, National Taiwan Ocean University, Keelung, Taiwan
| | | | - Sheng-Yu Guo
- Institute of Marine Biology and Centre of Excellence for the Oceans, National Taiwan Ocean University, Keelung, Taiwan
| | - Chi-Yu Shih
- Institute of Marine Biology and Centre of Excellence for the Oceans, National Taiwan Ocean University, Keelung, Taiwan
| | - Hans U Dahms
- Department of Biomedical Science and Environment Biology, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Jiang-Shiou Hwang
- Institute of Marine Biology and Centre of Excellence for the Oceans, National Taiwan Ocean University, Keelung, Taiwan
| | - Hyo-Jung Cha
- Institute of Marine Biology and Centre of Excellence for the Oceans, National Taiwan Ocean University, Keelung, Taiwan
| |
Collapse
|
15
|
Li H, O'Hair J, Thapa S, Bhatti S, Zhou S, Yang Y, Fish T, Thannhauser TW. Proteome profile changes during poly-hydroxybutyrate intracellular mobilization in gram positive Bacillus cereus tsu1. BMC Microbiol 2020; 20:122. [PMID: 32429845 PMCID: PMC7236355 DOI: 10.1186/s12866-020-01815-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 05/07/2020] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Bacillus cereus is a bacterial species which grows efficiently on a wide range of carbon sources and accumulates biopolymer poly-hydroxybutyrate (PHB) up to 80% cell dry weight. PHB is an aliphatic polymer produced and stored intracellularly as a reservoir of carbon and energy, its mobilization is a key biological process for sporulation in Bacillus spp. Previously, B. cereus tsu1 was isolated and cultured on rapeseed cake substrate (RCS), with maximum of PHB accumulation reached within 12 h, and depleted after 48 h. Fore-spore and spore structure were observed after 24 h culture. RESULTS Quantitative proteomic analysis of B. cereus tsu1 identified 2952 quantifiable proteins, and 244 significantly changed proteins (SCPs) in the 24 h:12 h pair of samples, and 325 SCPs in the 48 h:12 h pair of samples. Based on gene ontology classification analysis, biological processes enriched only in the 24 h:12 h SCPs include purine nucleotide metabolism, protein folding, metal ion homeostasis, response to stress, carboxylic acid catabolism, and cellular amino acid catabolism. The 48 h:12 h SCPs were enriched into processes including carbohydrate metabolism, protein metabolism, oxidative phosphorylation, and formation of translation ternary structure. A key enzyme for PHB metabolism, poly(R)-hydroxyalkanoic acid synthase (PhaC, KGT44865) accumulated significantly higher in 12 h-culture. Sporulation related proteins SigF and SpoEII were significantly higher in 24 h-samples. Enzymes for nitrate respiration and fermentation accumulated to the highest abundance level in 48 h-culture. CONCLUSIONS Changes in proteome of B. cereus tsu1 during PHB intracellular mobilization were characterized in this study. The key enzyme PhaC for PHB synthesis increased significantly after 12 h-culture which supports the highest PHB accumulation at this time point. The protein abundance level of SpoIIE and SigF also increased, correlating with sporulation in 24 h-culture. Enzymes for nitrate respiration and fermentation were significantly induced in 48 h-culture which indicates the depletion of oxygen at this stage and carbon flow towards fermentative growth. Results from this study provide insights into proteome profile changes during PHB accumulation and reuse, which can be applied to achieve a higher PHB yield and to improve bacterial growth performance and stress resistance.
Collapse
Affiliation(s)
- Hui Li
- Department of Agricultural and Environmental Sciences, College of Agriculture, Tennessee State University, 3500 John A. Merritt Blvd, Nashville, TN, 37209, USA
| | - Joshua O'Hair
- Department of Agricultural and Environmental Sciences, College of Agriculture, Tennessee State University, 3500 John A. Merritt Blvd, Nashville, TN, 37209, USA
| | - Santosh Thapa
- Department of Agricultural and Environmental Sciences, College of Agriculture, Tennessee State University, 3500 John A. Merritt Blvd, Nashville, TN, 37209, USA
| | - Sarabjit Bhatti
- Department of Agricultural and Environmental Sciences, College of Agriculture, Tennessee State University, 3500 John A. Merritt Blvd, Nashville, TN, 37209, USA
| | - Suping Zhou
- Department of Agricultural and Environmental Sciences, College of Agriculture, Tennessee State University, 3500 John A. Merritt Blvd, Nashville, TN, 37209, USA.
| | - Yong Yang
- R.W. Holley Center for Agriculture and Health, USDA-ARS, Cornell University, Ithaca, NY, 14853, USA
| | - Tara Fish
- R.W. Holley Center for Agriculture and Health, USDA-ARS, Cornell University, Ithaca, NY, 14853, USA
| | - Theodore W Thannhauser
- R.W. Holley Center for Agriculture and Health, USDA-ARS, Cornell University, Ithaca, NY, 14853, USA
| |
Collapse
|
16
|
van Munster JM, Daly P, Blythe MJ, Ibbett R, Kokolski M, Gaddipati S, Lindquist E, Singan VR, Barry KW, Lipzen A, Ngan CY, Petzold CJ, Chan LJG, Arvas M, Raulo R, Pullan ST, Delmas S, Grigoriev IV, Tucker GA, Simmons BA, Archer DB. Succession of physiological stages hallmarks the transcriptomic response of the fungus Aspergillus niger to lignocellulose. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:69. [PMID: 32313551 PMCID: PMC7155255 DOI: 10.1186/s13068-020-01702-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 03/24/2020] [Indexed: 05/04/2023]
Abstract
BACKGROUND Understanding how fungi degrade lignocellulose is a cornerstone of improving renewables-based biotechnology, in particular for the production of hydrolytic enzymes. Considerable progress has been made in investigating fungal degradation during time-points where CAZyme expression peaks. However, a robust understanding of the fungal survival strategies over its life time on lignocellulose is thereby missed. Here we aimed to uncover the physiological responses of the biotechnological workhorse and enzyme producer Aspergillus niger over its life time to six substrates important for biofuel production. RESULTS We analysed the response of A. niger to the feedstock Miscanthus and compared it with our previous study on wheat straw, alone or in combination with hydrothermal or ionic liquid feedstock pretreatments. Conserved (substrate-independent) metabolic responses as well as those affected by pretreatment and feedstock were identified via multivariate analysis of genome-wide transcriptomics combined with targeted transcript and protein analyses and mapping to a metabolic model. Initial exposure to all substrates increased fatty acid beta-oxidation and lipid metabolism transcripts. In a strain carrying a deletion of the ortholog of the Aspergillus nidulans fatty acid beta-oxidation transcriptional regulator farA, there was a reduction in expression of selected lignocellulose degradative CAZyme-encoding genes suggesting that beta-oxidation contributes to adaptation to lignocellulose. Mannan degradation expression was wheat straw feedstock-dependent and pectin degradation was higher on the untreated substrates. In the later life stages, known and novel secondary metabolite gene clusters were activated, which are of high interest due to their potential to synthesize bioactive compounds. CONCLUSION In this study, which includes the first transcriptional response of Aspergilli to Miscanthus, we highlighted that life time as well as substrate composition and structure (via variations in pretreatment and feedstock) influence the fungal responses to lignocellulose. We also demonstrated that the fungal response contains physiological stages that are conserved across substrates and are typically found outside of the conditions with high CAZyme expression, as exemplified by the stages that are dominated by lipid and secondary metabolism.
Collapse
Affiliation(s)
- Jolanda M. van Munster
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD UK
- Manchester Institute of Biotechnology (MIB) & School of Chemistry, The University of Manchester, Manchester, M1 7DN UK
| | - Paul Daly
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD UK
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
- Present Address: Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, People’s Republic of China
| | - Martin J. Blythe
- Deep Seq, Faculty of Medicine and Health Sciences, Queen’s Medical Centre, University of Nottingham, Nottingham, NG7 2UH UK
| | - Roger Ibbett
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD UK
| | - Matt Kokolski
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD UK
| | - Sanyasi Gaddipati
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD UK
| | - Erika Lindquist
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94598 USA
| | - Vasanth R. Singan
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94598 USA
| | - Kerrie W. Barry
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94598 USA
| | - Anna Lipzen
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94598 USA
| | - Chew Yee Ngan
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94598 USA
| | | | | | - Mikko Arvas
- VTT Technical Research Centre of Finland, Tietotie 2, P.O. Box FI-1000, 02044 VTT Espoo, Finland
| | - Roxane Raulo
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD UK
| | - Steven T. Pullan
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD UK
- Present Address: Public Health England, National Infection Service, Salisbury, UK
| | - Stéphane Delmas
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD UK
- Present Address: Laboratory of Computational and Quantitative Biology, Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, 75005 Paris, France
| | - Igor V. Grigoriev
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94598 USA
| | - Gregory A. Tucker
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD UK
| | | | - David B. Archer
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD UK
| |
Collapse
|
17
|
Aspergillus flavus NRRL 35739, a Poor Biocontrol Agent, May Have Increased Relative Expression of Stress Response Genes. J Fungi (Basel) 2019; 5:jof5020053. [PMID: 31226781 PMCID: PMC6616650 DOI: 10.3390/jof5020053] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Revised: 06/16/2019] [Accepted: 06/18/2019] [Indexed: 12/21/2022] Open
Abstract
Biocontrol of the mycotoxin aflatoxin utilizes non-aflatoxigenic strains of Aspergillus flavus, which have variable success rates as biocontrol agents. One non-aflatoxigenic strain, NRRL 35739, is a notably poor biocontrol agent. Its growth in artificial cultures and on peanut kernels was found to be slower than that of two aflatoxigenic strains, and NRRL 35739 exhibited less sporulation when grown on peanuts. The non-aflatoxigenic strain did not greatly prevent aflatoxin accumulation. Comparison of the transcriptomes of aflatoxigenic and non-aflatoxigenic A. flavus strains AF36, AF70, NRRL 3357, NRRL 35739, and WRRL 1519 indicated that strain NRRL 35739 had increased relative expression of six heat shock and stress response proteins, with the genes having relative read counts in NRRL 35739 that were 25 to 410 times more than in the other four strains. These preliminary findings tracked with current thought that aflatoxin biocontrol efficacy is related to the ability of a non-aflatoxigenic strain to out-compete aflatoxigenic ones. The slower growth of NRRL 35739 might be due to lower stress tolerance or overexpression of stress response(s). Further study of NRRL 35739 is needed to refine our understanding of the genetic basis of competitiveness among A. flavus strains.
Collapse
|
18
|
Cytochrome P450 Monooxygenase-Mediated Metabolic Utilization of Benzo[ a]Pyrene by Aspergillus Species. mBio 2019; 10:mBio.00558-19. [PMID: 31138742 PMCID: PMC6538779 DOI: 10.1128/mbio.00558-19] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We are increasingly exposed to environmental pollutants, including the carcinogen benzo[a]pyrene (BaP), which has prompted extensive research into human metabolism of toxicants. However, little is known about metabolic mechanisms employed by fungi that are able to use some toxic pollutants as the substrates for growth, leaving innocuous by-products. This study systemically demonstrates that a common soil-dwelling fungus is able to use benzo[a]pyrene as food, which results in expression and metabolic changes associated with growth and energy generation. Importantly, this study reveals key components of the metabolic utilization of BaP, notably a cytochrome P450 monooxygenase and the fungal NF-κB-type transcriptional regulators. Our study advances fundamental knowledge of fungal BaP metabolism and provides novel insight into designing and implementing enhanced bioremediation strategies. Soil-dwelling fungal species possess the versatile metabolic capability to degrade complex organic compounds that are toxic to humans, yet the mechanisms they employ remain largely unknown. Benzo[a]pyrene (BaP) is a pervasive carcinogenic contaminant, posing a significant concern for human health. Here, we report that several Aspergillus species are capable of degrading BaP. Exposing Aspergillus nidulans cells to BaP results in transcriptomic and metabolic changes associated with cellular growth and energy generation, implying that the fungus utilizes BaP as a growth substrate. Importantly, we identify and characterize the conserved bapA gene encoding a cytochrome P450 monooxygenase that is necessary for the metabolic utilization of BaP in Aspergillus. We further demonstrate that the fungal NF-κB-type velvet regulators VeA and VelB are required for proper expression of bapA in response to nutrient limitation and BaP degradation in A. nidulans. Our study illuminates fundamental knowledge of fungal BaP metabolism and provides novel insights into enhancing bioremediation potential.
Collapse
|
19
|
Chaves EGA, Parente-Rocha JA, Baeza LC, Araújo DS, Borges CL, de Oliveira MAP, Soares CMDA. Proteomic Analysis of Paracoccidioides brasiliensis During Infection of Alveolar Macrophages Primed or Not by Interferon-Gamma. Front Microbiol 2019; 10:96. [PMID: 30804901 PMCID: PMC6371752 DOI: 10.3389/fmicb.2019.00096] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 01/16/2019] [Indexed: 12/31/2022] Open
Abstract
Although members of the Paracoccidioides complex are not obligate intracellular pathogens, they present the ability to survive and multiply inside epithelial cells and phagocytes of mammals, which may favor the spread of the fungus in host tissues. Macrophages resident in the lung are the first line of defense against paracoccidioidomycosis (PCM), presenting mechanisms to control the pathogen dissemination through the granuloma formation or eliminating the fungus through phagocytosis. Phagocytosis triggers an oxidative burst, in which there is an increase in the production of toxic elements, derived from oxygen and nitrogen. The interior of the phagolysosome is a harsh environment to the internalized pathogens, since in addition to the oxygen and nitrogen reactive species, microorganisms face nutrient shortages and proteases activity. Through the NanoUPLC-MSE technology, we analyzed the proteomic response of Paracoccidioides brasiliensis during the infection of alveolar macrophages primed or not by interferon gamma (IFN-γ). At 6 hs post-infection, only (IFN-γ)-primed macrophages were able to kill the fungus. We observed the regulation of amino acids degradation, tricarboxylic acid cycle, respiratory chain, ATP synthesis, glyoxylate cycle, as well as an increase in the expression of defense proteins related to oxidative stress, heat shock, and virulence factors under both conditions analyzed. However, some pathways described as essential for the survival of pathogens inside macrophages were observed only or with higher intensity in yeast cells recovered from non-primed macrophages, as phosphate pentoses pathway, methylcitrate cycle, synthesis of cell wall components, and mitochondrial activity. The data indicate that the intracellular environment of non-primed macrophages could be more permissive to the survival and multiplication of P. brasiliensis. The identification of key molecules for the establishment of infection can help the understanding of the nature of the parasite–host relationship and pathogenesis of PCM.
Collapse
Affiliation(s)
- Edilânia Gomes Araújo Chaves
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Brazil
| | - Juliana Alves Parente-Rocha
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Brazil
| | - Lilian Cristiane Baeza
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Brazil.,Centro de Ciências Médicas e Farmacêuticas, Universidade Estadual do Oeste do Paraná, Cascavel, Brazil
| | - Danielle Silva Araújo
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Brazil
| | - Clayton Luiz Borges
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Brazil
| | | | | |
Collapse
|
20
|
Lopez-Moya F, Suarez-Fernandez M, Lopez-Llorca LV. Molecular Mechanisms of Chitosan Interactions with Fungi and Plants. Int J Mol Sci 2019; 20:E332. [PMID: 30650540 PMCID: PMC6359256 DOI: 10.3390/ijms20020332] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 01/07/2019] [Accepted: 01/11/2019] [Indexed: 12/19/2022] Open
Abstract
Chitosan is a versatile compound with multiple biotechnological applications. This polymer inhibits clinically important human fungal pathogens under the same carbon and nitrogen status as in blood. Chitosan permeabilises their high-fluidity plasma membrane and increases production of intracellular oxygen species (ROS). Conversely, chitosan is compatible with mammalian cell lines as well as with biocontrol fungi (BCF). BCF resistant to chitosan have low-fluidity membranes and high glucan/chitin ratios in their cell walls. Recent studies illustrate molecular and physiological basis of chitosan-root interactions. Chitosan induces auxin accumulation in Arabidopsis roots. This polymer causes overexpression of tryptophan-dependent auxin biosynthesis pathway. It also blocks auxin translocation in roots. Chitosan is a plant defense modulator. Endophytes and fungal pathogens evade plant immunity converting chitin into chitosan. LysM effectors shield chitin and protect fungal cell walls from plant chitinases. These enzymes together with fungal chitin deacetylases, chitosanases and effectors play determinant roles during fungal colonization of plants. This review describes chitosan mode of action (cell and gene targets) in fungi and plants. This knowledge will help to develop chitosan for agrobiotechnological and medical applications.
Collapse
Affiliation(s)
- Federico Lopez-Moya
- Department of Marine Sciences and Applied Biology, Laboratory of Plant Pathology, Multidisciplinary Institute for Environmental Studies (MIES) Ramon Margalef, University of Alicante, 03080 Alicante, Spain.
| | - Marta Suarez-Fernandez
- Department of Marine Sciences and Applied Biology, Laboratory of Plant Pathology, Multidisciplinary Institute for Environmental Studies (MIES) Ramon Margalef, University of Alicante, 03080 Alicante, Spain.
| | - Luis Vicente Lopez-Llorca
- Department of Marine Sciences and Applied Biology, Laboratory of Plant Pathology, Multidisciplinary Institute for Environmental Studies (MIES) Ramon Margalef, University of Alicante, 03080 Alicante, Spain.
| |
Collapse
|
21
|
Pawlik A, Mazur A, Wielbo J, Koper P, Żebracki K, Kubik-Komar A, Janusz G. RNA Sequencing Reveals Differential Gene Expression of Cerrena Unicolor in Response to Variable Lighting Conditions. Int J Mol Sci 2019; 20:ijms20020290. [PMID: 30642073 PMCID: PMC6358801 DOI: 10.3390/ijms20020290] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 01/04/2019] [Accepted: 01/09/2019] [Indexed: 11/16/2022] Open
Abstract
To elucidate the light-dependent gene expression in Cerrena unicolor FCL139, the transcriptomes of the fungus growing in white, blue, green, and red lighting conditions and darkness were analysed. Among 10,413 all-unigenes detected in C. unicolor, 7762 were found to be expressed in all tested conditions. Transcripts encoding putative fungal photoreceptors in the C. unicolor transcriptome were identified. The number of transcripts uniquely produced by fungus ranged from 20 during its growth in darkness to 112 in the green lighting conditions. We identified numerous genes whose expression differed substantially between the darkness (control) and each of the light variants tested, with the greatest number of differentially expressed genes (DEGs) (454 up- and 457 down-regulated) observed for the white lighting conditions. The DEGs comprised those involved in primary carbohydrate metabolism, amino acid metabolism, autophagy, nucleotide repair systems, signalling pathways, and carotenoid metabolism as defined using Kyoto Encyclopedia of Genes and Genomes (KEGG) database. The analysis of the expression profile of genes coding for lignocellulose-degrading enzymes suggests that the wood-degradation properties of C. unicolor may be independent of the lighting conditions and may result from the overall stimulation of fungal metabolism by daylight.
Collapse
Affiliation(s)
- Anna Pawlik
- Department of Biochemistry, Maria Curie-Skłodowska University, Akademicka 19 St., 20-033 Lublin, Poland.
| | - Andrzej Mazur
- Department of Genetics and Microbiology, Maria Curie-Skłodowska University, Akademicka 19 St., 20-033 Lublin, Poland.
| | - Jerzy Wielbo
- Department of Genetics and Microbiology, Maria Curie-Skłodowska University, Akademicka 19 St., 20-033 Lublin, Poland.
| | - Piotr Koper
- Department of Genetics and Microbiology, Maria Curie-Skłodowska University, Akademicka 19 St., 20-033 Lublin, Poland.
| | - Kamil Żebracki
- Department of Genetics and Microbiology, Maria Curie-Skłodowska University, Akademicka 19 St., 20-033 Lublin, Poland.
| | - Agnieszka Kubik-Komar
- Chair of Applied Mathematics and Informatics, Lublin University of Life Sciences, Akademicka 13 St., 20-950 Lublin, Poland.
| | - Grzegorz Janusz
- Department of Biochemistry, Maria Curie-Skłodowska University, Akademicka 19 St., 20-033 Lublin, Poland.
| |
Collapse
|
22
|
Zhao G, Ding LL, Pan ZH, Kong DH, Hadiatullah H, Fan ZC. Proteinase and glycoside hydrolase production is enhanced in solid-state fermentation by manipulating the carbon and nitrogen fluxes in Aspergillus oryzae. Food Chem 2018; 271:606-613. [PMID: 30236722 DOI: 10.1016/j.foodchem.2018.07.199] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 07/07/2018] [Accepted: 07/25/2018] [Indexed: 02/07/2023]
Abstract
Soy sauce materials of soybean meal and wheat bran were evaluated in solid-state (koji) fermentation (SSF) and submerged fermentation (SmF) by Aspergillus oryzae. Proteinase production in SSF (2331 ± 39 U g-1) was about 4.9 times higher than that in SmF (477 ± 13 U g-1), and glycoside hydrolase was approximately 2 times higher in SSF than that in SmF. In addition, protein expression of iTRAQ analysis deepens our understanding of the secreting mechanism. Abundant proteinases (dipeptidase, dipeptidyl aminopeptidase, puromycin-sensitive aminopeptidase, Xaa-pro aminopeptidase, neutral protease 2 and leucine aminopeptidase 2), along with the glycoside hydrolase (glycoamylase, glucosidase and β-xylanase) were secreted at the late stage of SSF, but tripeptidyl peptidase sed 2 was proposed as an indispensable protease in SmF or the early stage of SSF. Several metabolites associated with the carbon flux and amino acid biosynthesis were proved to be regulated by the proteinase and glycoside hydrolase production.
Collapse
Affiliation(s)
- Guozhong Zhao
- State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Food Nutrition and Safety, Ministry of Education, International Collaborative Research Center for Health Biotechnology, College of Food Science and Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, China; Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Technology and Business University (BTBU), Bingjin 100048, China
| | - Li-Li Ding
- State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Food Nutrition and Safety, Ministry of Education, International Collaborative Research Center for Health Biotechnology, College of Food Science and Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, China
| | - Zhi-Hui Pan
- Guangzhou Jammy Chai Sauce Workshop Co., Ltd., Guangzhou 510403, China
| | - De-Hua Kong
- Guangzhou Jammy Chai Sauce Workshop Co., Ltd., Guangzhou 510403, China
| | - Hadiatullah Hadiatullah
- State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Food Nutrition and Safety, Ministry of Education, International Collaborative Research Center for Health Biotechnology, College of Food Science and Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, China
| | - Zhen-Chuan Fan
- State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Food Nutrition and Safety, Ministry of Education, International Collaborative Research Center for Health Biotechnology, College of Food Science and Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, China.
| |
Collapse
|
23
|
Fasoyin OE, Wang B, Qiu M, Han X, Chung KR, Wang S. Carbon catabolite repression gene creA regulates morphology, aflatoxin biosynthesis and virulence in Aspergillus flavus. Fungal Genet Biol 2018; 115:41-51. [DOI: 10.1016/j.fgb.2018.04.008] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 04/08/2018] [Accepted: 04/11/2018] [Indexed: 11/24/2022]
|
24
|
Kurucz V, Krüger T, Antal K, Dietl AM, Haas H, Pócsi I, Kniemeyer O, Emri T. Additional oxidative stress reroutes the global response of Aspergillus fumigatus to iron depletion. BMC Genomics 2018; 19:357. [PMID: 29747589 PMCID: PMC5946477 DOI: 10.1186/s12864-018-4730-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 04/26/2018] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Aspergillus fumigatus has to cope with a combination of several stress types while colonizing the human body. A functional interplay between these different stress responses can increase the chances of survival for this opportunistic human pathogen during the invasion of its host. In this study, we shed light on how the H2O2-induced oxidative stress response depends on the iron available to this filamentous fungus, using transcriptomic analysis, proteomic profiles, and growth assays. RESULTS The applied H2O2 treatment, which induced only a negligible stress response in iron-replete cultures, deleteriously affected the fungus under iron deprivation. The majority of stress-induced changes in gene and protein expression was not predictable from data coming from individual stress exposure and was only characteristic for the combination of oxidative stress plus iron deprivation. Our experimental data suggest that the physiological effects of combined stresses and the survival of the fungus highly depend on fragile balances between economization of iron and production of essential iron-containing proteins. One observed strategy was the overproduction of iron-independent antioxidant proteins to combat oxidative stress during iron deprivation, e.g. the upregulation of superoxide dismutase Sod1, the thioredoxin reductase Trr1, and the thioredoxin orthologue Afu5g11320. On the other hand, oxidative stress induction overruled iron deprivation-mediated repression of several genes. In agreement with the gene expression data, growth studies underlined that in A. fumigatus iron deprivation aggravates oxidative stress susceptibility. CONCLUSIONS Our data demonstrate that studying stress responses under separate single stress conditions is not sufficient to understand how A. fumigatus adapts in a complex and hostile habitat like the human body. The combinatorial stress of iron depletion and hydrogen peroxide caused clear non-additive effects upon the stress response of A. fumigatus. Our data further supported the view that the ability of A. fumigatus to cause diseases in humans strongly depends on its fitness attributes and less on specific virulence factors. In summary, A. fumigatus is able to mount and coordinate complex and efficient responses to combined stresses like iron deprivation plus H2O2-induced oxidative stress, which are exploited by immune cells to kill fungal pathogens.
Collapse
Affiliation(s)
- Vivien Kurucz
- Department of Biotechnology and Microbiology, Faculty of Sciences and Technology, University of Debrecen, Egyetem tér 1, Debrecen, H-4032 Hungary
| | - Thomas Krüger
- Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (HKI), 07745 Jena, Germany
| | - Károly Antal
- Department of Zoology, Faculty of Sciences, Eszterházy Károly University, Eszterházy tér 1, Eger, H-3300 Hungary
| | - Anna-Maria Dietl
- Division of Molecular Biology, Biocenter, Medical University of Innsbruck, A6020 Innsbruck, Austria
| | - Hubertus Haas
- Division of Molecular Biology, Biocenter, Medical University of Innsbruck, A6020 Innsbruck, Austria
| | - István Pócsi
- Department of Biotechnology and Microbiology, Faculty of Sciences and Technology, University of Debrecen, Egyetem tér 1, Debrecen, H-4032 Hungary
| | - Olaf Kniemeyer
- Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (HKI), 07745 Jena, Germany
| | - Tamás Emri
- Department of Biotechnology and Microbiology, Faculty of Sciences and Technology, University of Debrecen, Egyetem tér 1, Debrecen, H-4032 Hungary
| |
Collapse
|
25
|
Itoh E, Odakura R, Oinuma KI, Shimizu M, Masuo S, Takaya N. Sirtuin E is a fungal global transcriptional regulator that determines the transition from the primary growth to the stationary phase. J Biol Chem 2017; 292:11043-11054. [PMID: 28465348 PMCID: PMC5491787 DOI: 10.1074/jbc.m116.753772] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Revised: 04/20/2017] [Indexed: 11/06/2022] Open
Abstract
In response to limited nutrients, fungal cells exit the primary growth phase, enter the stationary phase, and cease proliferation. Although fundamental to microbial physiology in many environments, the regulation of this transition is poorly understood but likely involves many transcriptional regulators. These may include the sirtuins, which deacetylate acetyllysine residues of histones and epigenetically regulate global transcription. Therefore, we investigated the role of a nuclear sirtuin, sirtuin E (SirE), from the ascomycete fungus Aspergillus nidulans An A. nidulans strain with a disrupted sirE gene (SirEΔ) accumulated more acetylated histone H3 during the stationary growth phase when sirE was expressed at increased levels in the wild type. SirEΔ exhibited decreased mycelial autolysis, conidiophore development, sterigmatocystin biosynthesis, and production of extracellular hydrolases. Moreover, the transcription of the genes involved in these processes was also decreased, indicating that SirE is a histone deacetylase that up-regulates these activities in the stationary growth phase. Transcriptome analyses indicated that SirE repressed primary carbon and nitrogen metabolism and cell-wall synthesis. Chromatin immunoprecipitation demonstrated that SirE deacetylates acetylated Lys-9 residues in histone H3 at the gene promoters of α-1,3-glucan synthase (agsB), glycolytic phosphofructokinase (pfkA), and glyceraldehyde 3-phosphate (gpdA), indicating that SirE represses the expression of these primary metabolic genes. In summary, these results indicate that SirE facilitates the metabolic transition from the primary growth phase to the stationary phase. Because the observed gene expression profiles in stationary phase matched those resulting from carbon starvation, SirE appears to control this metabolic transition via a mechanism associated with the starvation response.
Collapse
Affiliation(s)
- Eriko Itoh
- From the Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
| | - Rika Odakura
- From the Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
| | - Ken-Ichi Oinuma
- From the Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
| | - Motoyuki Shimizu
- From the Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
| | - Shunsuke Masuo
- From the Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
| | - Naoki Takaya
- From the Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
| |
Collapse
|
26
|
The low affinity glucose transporter HxtB is also involved in glucose signalling and metabolism in Aspergillus nidulans. Sci Rep 2017; 7:45073. [PMID: 28361917 PMCID: PMC5374493 DOI: 10.1038/srep45073] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 02/17/2017] [Indexed: 02/06/2023] Open
Abstract
One of the drawbacks during second-generation biofuel production from plant lignocellulosic biomass is the accumulation of glucose, the preferred carbon source of microorganisms, which causes the repression of hydrolytic enzyme secretion by industrially relevant filamentous fungi. Glucose sensing, subsequent transport and cellular signalling pathways have been barely elucidated in these organisms. This study therefore characterized the transcriptional response of the filamentous fungus Aspergillus nidulans to the presence of high and low glucose concentrations under continuous chemostat cultivation with the aim to identify novel factors involved in glucose sensing and signalling. Several transcription factor- and transporter-encoding genes were identified as being differentially regulated, including the previously characterized glucose and xylose transporter HxtB. HxtB was confirmed to be a low affinity glucose transporter, localizing to the plasma membrane under low- and high-glucose conditions. Furthermore, HxtB was shown to be involved in conidiation-related processes and may play a role in downstream glucose signalling. A gene predicted to encode the protein kinase PskA was also identified as being important for glucose metabolism. This study identified several proteins with predicted roles in glucose metabolic processes and provides a foundation for further investigation into the response of biotechnologically important filamentous fungi to glucose.
Collapse
|
27
|
Detection of Transcriptionally Active Mycotoxin Gene Clusters: DNA Microarray. Methods Mol Biol 2016. [PMID: 27924550 DOI: 10.1007/978-1-4939-6707-0_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Various bioanalytical tools including DNA microarrays are frequently used to map global transcriptional changes in mycotoxin producer filamentous fungi. This effective hybridization-based transcriptomics technology helps researchers to identify genes of secondary metabolite gene clusters and record concomitant gene expression changes in these clusters initiated by versatile environmental conditions and/or gene deletions. Such transcriptional data are of great value when future mycotoxin control technologies are considered and elaborated. Giving the readers insights into RNA extraction and DNA microarray hybridization steps routinely used in our laboratories and also into the normalization and evaluation of primary gene expression data, we would like to contribute to the interlaboratory standardization of DNA microarray based transcriptomics studies being carried out in many laboratories worldwide in this important field of fungal biology.
Collapse
|
28
|
The CreB deubiquitinating enzyme does not directly target the CreA repressor protein in Aspergillus nidulans. Curr Genet 2016; 63:647-667. [DOI: 10.1007/s00294-016-0666-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 08/23/2016] [Accepted: 08/24/2016] [Indexed: 12/12/2022]
|
29
|
Matsui M, Yokoyama T, Nemoto K, Kumagai T, Terai G, Tamano K, Machida M, Shibata T. Identification of a putative FR901469 biosynthesis gene cluster in fungal sp. No. 11243 and enhancement of the productivity by overexpressing the transcription factor gene frbF. J Biosci Bioeng 2016; 123:147-153. [PMID: 27660098 DOI: 10.1016/j.jbiosc.2016.08.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2016] [Revised: 08/14/2016] [Accepted: 08/17/2016] [Indexed: 01/02/2023]
Abstract
FR901469 is an antifungal antibiotic produced by fungal sp. No. 11243. Here, we searched for FR901469 biosynthesis genes in the genome of No. 11243. Based on the molecular structure of FR901469 and endogenous functional motifs predicted in each genomic NRPS gene, a putative FR901469 biosynthesis gene cluster harboring the most plausible NRPS gene was identified. A transcription factor gene, designated frbF, was found in the cluster. To improve FR901469 productivity, we constructed a strain in which frbF was overexpressed and named it TFH2-2. FR901469 productivity of TFH2-2 was 3.4 times higher than that of the wild-type strain. Transcriptome analysis revealed that most of the genes in the putative FR901469 biosynthesis gene cluster were upregulated in TFH2-2. It also showed that the expression of genes related to ergosterol biosynthesis, β-1,3-glucan catabolism, and chitin synthesis was inclined to exhibit significant differences in TFH2-2.
Collapse
Affiliation(s)
- Makoto Matsui
- Biotechnology Labs, Astellas Pharma Inc., 5-2-3 Tokodai, Tsukuba-shi, Ibaraki 300-2698, Japan; Technology Research Association of Highly Efficient Gene Design (TRAHED), 17-2-1 Higashi-Nijo, Tsukisamu, Toyohira-ku, Sapporo, Hokkaido 062-8517, Japan.
| | - Tatsuya Yokoyama
- Biotechnology Labs, Astellas Pharma Inc., 5-2-3 Tokodai, Tsukuba-shi, Ibaraki 300-2698, Japan; Technology Research Association of Highly Efficient Gene Design (TRAHED), 17-2-1 Higashi-Nijo, Tsukisamu, Toyohira-ku, Sapporo, Hokkaido 062-8517, Japan
| | - Kaoru Nemoto
- Technology Research Association of Highly Efficient Gene Design (TRAHED), 17-2-1 Higashi-Nijo, Tsukisamu, Toyohira-ku, Sapporo, Hokkaido 062-8517, Japan
| | - Toshitaka Kumagai
- Technology Research Association of Highly Efficient Gene Design (TRAHED), 17-2-1 Higashi-Nijo, Tsukisamu, Toyohira-ku, Sapporo, Hokkaido 062-8517, Japan; Fermlab, Inc., 4-3-1-913 Shirakawa, Koto-ku, Tokyo 135-0021, Japan
| | - Goro Terai
- INTEC Inc, 1-3-3 Shinsuna Koto-ku, Tokyo 136-8637, Japan; Computational Biology Research Center, National Institute of Advanced Industrial Science and Technology (AIST), 2-41-6 Aomi, Koto-ku, Tokyo 135-0064, Japan
| | - Koichi Tamano
- Technology Research Association of Highly Efficient Gene Design (TRAHED), 17-2-1 Higashi-Nijo, Tsukisamu, Toyohira-ku, Sapporo, Hokkaido 062-8517, Japan; Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 17-2-1 Higashi-Nijo, Tsukisamu, Toyohira-ku, Sapporo, Hokkaido 062-8517, Japan
| | - Masayuki Machida
- Technology Research Association of Highly Efficient Gene Design (TRAHED), 17-2-1 Higashi-Nijo, Tsukisamu, Toyohira-ku, Sapporo, Hokkaido 062-8517, Japan; Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 17-2-1 Higashi-Nijo, Tsukisamu, Toyohira-ku, Sapporo, Hokkaido 062-8517, Japan
| | - Takashi Shibata
- Biotechnology Labs, Astellas Pharma Inc., 5-2-3 Tokodai, Tsukuba-shi, Ibaraki 300-2698, Japan; Technology Research Association of Highly Efficient Gene Design (TRAHED), 17-2-1 Higashi-Nijo, Tsukisamu, Toyohira-ku, Sapporo, Hokkaido 062-8517, Japan
| |
Collapse
|
30
|
Alam MA, Kamlangdee N, Kelly JM. The CreB deubiquitinating enzyme does not directly target the CreA repressor protein in Aspergillus nidulans. Curr Genet 2016:10.1007/s00294-016-0643-x. [PMID: 27589970 DOI: 10.1007/s00294-016-0643-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 08/23/2016] [Accepted: 08/24/2016] [Indexed: 11/25/2022]
Abstract
Ubiquitination/deubiquitination pathways are now recognized as key components of gene regulatory mechanisms in eukaryotes. The major transcriptional repressor for carbon catabolite repression in Aspergillus nidulans is CreA, and mutational analysis led to the suggestion that a regulatory ubiquitination/deubiquitination pathway is involved. A key unanswered question is if and how this pathway, comprising CreB (deubiquitinating enzyme) and HulA (ubiquitin ligase) and other proteins, is involved in the regulatory mechanism. Previously, missense alleles of creA and creB were analysed for genetic interactions, and here we extended this to complete loss-of-function alleles of creA and creB, and compared morphological and biochemical phenotypes, which confirmed genetic interaction between the genes. We investigated whether CreA, or a protein in a complex with it, is a direct target of the CreB deubiquitination enzyme, using co-purifications of CreA and CreB, first using strains that overexpress the proteins and then using strains that express the proteins from their native promoters. The Phos-tag system was used to show that CreA is a phosphorylated protein, but no ubiquitination was detected using anti-ubiquitin antibodies and Western analysis. These findings were confirmed using mass spectrometry, which confirmed that CreA was differentially phosphorylated but not ubiquitinated. Thus, CreA is not a direct target of CreB, and nor are proteins that form part of a stable complex with CreA a target of CreB. These results open up new questions regarding the molecular mechanism of CreA repressing activity, and how the ubiquitination pathway involving CreB interacts with this regulatory network.
Collapse
Affiliation(s)
- Md Ashiqul Alam
- Department of Genetics and Evolution, The University of Adelaide, Adelaide, 5005, Australia
| | - Niyom Kamlangdee
- Department of Genetics and Evolution, The University of Adelaide, Adelaide, 5005, Australia
- Walailak University, 222 Thaiburi Thasala, Nakhonsithamrat, Nakhon Si Thammarat, 80160, Thailand
| | - Joan M Kelly
- Department of Genetics and Evolution, The University of Adelaide, Adelaide, 5005, Australia.
| |
Collapse
|
31
|
Bromley M, Johns A, Davies E, Fraczek M, Mabey Gilsenan J, Kurbatova N, Keays M, Kapushesky M, Gut M, Gut I, Denning DW, Bowyer P. Mitochondrial Complex I Is a Global Regulator of Secondary Metabolism, Virulence and Azole Sensitivity in Fungi. PLoS One 2016; 11:e0158724. [PMID: 27438017 PMCID: PMC4954691 DOI: 10.1371/journal.pone.0158724] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 06/21/2016] [Indexed: 12/12/2022] Open
Abstract
Recent estimates of the global burden of fungal disease suggest that that their incidence has been drastically underestimated and that mortality may rival that of malaria or tuberculosis. Azoles are the principal class of antifungal drug and the only available oral treatment for fungal disease. Recent occurrence and increase in azole resistance is a major concern worldwide. Known azole resistance mechanisms include over—expression of efflux pumps and mutation of the gene encoding the target protein cyp51a, however, for one of the most important fungal pathogens of humans, Aspergillus fumigatus, much of the observed azole resistance does not appear to involve such mechanisms. Here we present evidence that azole resistance in A. fumigatus can arise through mutation of components of mitochondrial complex I. Gene deletions of the 29.9KD subunit of this complex are azole resistant, less virulent and exhibit dysregulation of secondary metabolite gene clusters in a manner analogous to deletion mutants of the secondary metabolism regulator, LaeA. Additionally we observe that a mutation leading to an E180D amino acid change in the 29.9 KD subunit is strongly associated with clinical azole resistant A. fumigatus isolates. Evidence presented in this paper suggests that complex I may play a role in the hypoxic response and that one possible mechanism for cell death during azole treatment is a dysfunctional hypoxic response that may be restored by dysregulation of complex I. Both deletion of the 29.9 KD subunit of complex I and azole treatment alone profoundly change expression of gene clusters involved in secondary metabolism and immunotoxin production raising potential concerns about long term azole therapy.
Collapse
Affiliation(s)
- Mike Bromley
- Manchester Fungal Infection Group, Institute of Inflammation and Repair, Faculty of Medicine and Human Sciences, University of Manchester, 2.24 Core technology Building, Grafton St., Manchester, M13 9NT, United Kingdom
| | - Anna Johns
- Manchester Fungal Infection Group, Institute of Inflammation and Repair, Faculty of Medicine and Human Sciences, University of Manchester, 2.24 Core technology Building, Grafton St., Manchester, M13 9NT, United Kingdom
| | - Emma Davies
- National Aspergillosis Centre, University Hospital of South Manchester, University of Manchester, School of Translational Medicine, Manchester Academic Health Science Centre, 2nd Floor Education & Research Centre, University of Manchester, Manchester, M23 9LT, United Kingdom
| | - Marcin Fraczek
- Manchester Fungal Infection Group, Institute of Inflammation and Repair, Faculty of Medicine and Human Sciences, University of Manchester, 2.24 Core technology Building, Grafton St., Manchester, M13 9NT, United Kingdom
| | - Jane Mabey Gilsenan
- Manchester Fungal Infection Group, Institute of Inflammation and Repair, Faculty of Medicine and Human Sciences, University of Manchester, 2.24 Core technology Building, Grafton St., Manchester, M13 9NT, United Kingdom
| | - Natalya Kurbatova
- The EMBL-European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, United Kingdom
| | - Maria Keays
- The EMBL-European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, United Kingdom
| | - Misha Kapushesky
- The EMBL-European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, United Kingdom
| | - Marta Gut
- Centro Nacional de Analisis Genomico, Parc Cientific de Barcelona, Baldiri Reixac, 4, PCB - Tower I, 08028 Barcelona, Spain
| | - Ivo Gut
- Centro Nacional de Analisis Genomico, Parc Cientific de Barcelona, Baldiri Reixac, 4, PCB - Tower I, 08028 Barcelona, Spain
| | - David W. Denning
- National Aspergillosis Centre, University Hospital of South Manchester, University of Manchester, School of Translational Medicine, Manchester Academic Health Science Centre, 2nd Floor Education & Research Centre, University of Manchester, Manchester, M23 9LT, United Kingdom
| | - Paul Bowyer
- Manchester Fungal Infection Group, Institute of Inflammation and Repair, Faculty of Medicine and Human Sciences, University of Manchester, 2.24 Core technology Building, Grafton St., Manchester, M13 9NT, United Kingdom
- National Aspergillosis Centre, University Hospital of South Manchester, University of Manchester, School of Translational Medicine, Manchester Academic Health Science Centre, 2nd Floor Education & Research Centre, University of Manchester, Manchester, M23 9LT, United Kingdom
- * E-mail:
| |
Collapse
|
32
|
Vorapreeda T, Thammarongtham C, Laoteng K. Integrative computational approach for genome-based study of microbial lipid-degrading enzymes. World J Microbiol Biotechnol 2016; 32:122. [DOI: 10.1007/s11274-016-2067-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 04/05/2016] [Indexed: 01/19/2023]
|
33
|
Mukherjee S, Chandrababunaidu MM, Panda A, Khowala S, Tripathy S. Tricking Arthrinium malaysianum into Producing Industrially Important Enzymes Under 2-Deoxy D-Glucose Treatment. Front Microbiol 2016; 7:596. [PMID: 27242677 PMCID: PMC4865484 DOI: 10.3389/fmicb.2016.00596] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Accepted: 04/11/2016] [Indexed: 01/24/2023] Open
Abstract
This study catalogs production of industrially important enzymes and changes in transcript expression caused by 2-deoxy D-glucose (2-DG) treatment in Arthrinium malaysianum cultures. Carbon Catabolite Repression (CCR) induced by 2-DG in this species is cAMP independent unlike many other organisms. Higher levels of secreted endoglucanase (EG), β-glucosidase (BGL), β-xylosidase (BXL), and filter paper activity assay (FPase) enzymes under 2-DG treatment can be exploited for commercial purposes. An integrated RNA sequencing and quantitative proteomic analysis was performed to investigate the cellular response to 2-DG in A. malaysianum. Analysis of RNASeq data under 2-DG treated and control condition reveals that 56% of the unigenes do not have any known similarity to proteins in non-redundant database. Gene Ontology IDs were assigned to 36% of the transcripts (13260) and about 5207 (14%) were mapped to Kyoto Encyclopedia of Genes and Genomes pathway (KEGG). About 1711 genes encoding 2691 transcripts were differentially expressed in treated vs. control samples. Out of the 2691 differentially expressed transcripts, only 582 have any known function. The most up regulated genes belonged to Pentose Phosphate Pathways and carbohydrate degradation class as expected. In addition, genes involved in protein folding, binding, catalytic activity, DNA repair, and secondary metabolites were up-regulated under 2-DG treatment. Whereas genes encoding glycosylation pathways, growth, nutrient reservoir activity was repressed. Gene ontology analysis of the differentially expressed genes indicates metabolic process (35%) is the pre-dominant class followed by carbohydrate degradation (11%), protein folding, and trafficking (6.2%) and transport (5.3%) classes. Unlike other organisms, conventional unfolded protein response (UPR) was not activated in either control or treated conditions. Major enzymes secreted by A. malaysianum are those degrading plant polysaccharides, the most dominant ones being β-glucosidase, as demonstrated by the 2D gel analysis. A set of 7 differentially expressed mRNAs were validated by qPCR. Transmission electron microscopy analyses demonstrated that the 2-DG treated cell walls of hyphae showed significant differences in the cell-wall thickness. Overall 2-DG treatment in A. malaysianum induced secretion of large amount of commercially viable enzymes compared to other known species.
Collapse
Affiliation(s)
- Soumya Mukherjee
- Drug Development Diagnostic and Biotechnology Division, Council of Scientific and Industrial Research-Indian Institute of Chemical BiologyKolkata, India
| | - Mathu Malar Chandrababunaidu
- Structural Biology and Bioinformatics Division, Council of Scientific and Industrial Research-Indian Institute of Chemical BiologyKolkata, India
| | - Arijit Panda
- Structural Biology and Bioinformatics Division, Council of Scientific and Industrial Research-Indian Institute of Chemical BiologyKolkata, India
| | - Suman Khowala
- Drug Development Diagnostic and Biotechnology Division, Council of Scientific and Industrial Research-Indian Institute of Chemical BiologyKolkata, India
| | - Sucheta Tripathy
- Structural Biology and Bioinformatics Division, Council of Scientific and Industrial Research-Indian Institute of Chemical BiologyKolkata, India
| |
Collapse
|
34
|
Manzanares-Miralles L, Sarikaya-Bayram Ö, Smith EB, Dolan SK, Bayram Ö, Jones GW, Doyle S. Quantitative proteomics reveals the mechanism and consequence of gliotoxin-mediated dysregulation of the methionine cycle in Aspergillus niger. J Proteomics 2016; 131:149-162. [DOI: 10.1016/j.jprot.2015.10.024] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 10/14/2015] [Accepted: 10/18/2015] [Indexed: 12/25/2022]
|
35
|
Leiter É, Bálint M, Miskei M, Orosz E, Szabó Z, Pócsi I. Stress tolerances of nullmutants of function-unknown genes encoding menadione stress-responsive proteins inAspergillus nidulans. J Basic Microbiol 2015; 56:827-33. [DOI: 10.1002/jobm.201500500] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 11/11/2015] [Indexed: 12/27/2022]
Affiliation(s)
- Éva Leiter
- Faculty of Science and Technology, Department of Biotechnology and Microbiology; University of Debrecen; Debrecen Hungary
| | - Mihály Bálint
- Faculty of Science and Technology, Department of Biotechnology and Microbiology; University of Debrecen; Debrecen Hungary
| | - Márton Miskei
- MTA-DE Momentum, Laboratory of Protein Dynamics, Department of Biochemistry and Molecular Biology; University of Debrecen; Debrecen Hungary
| | - Erzsébet Orosz
- Faculty of Science and Technology, Department of Biotechnology and Microbiology; University of Debrecen; Debrecen Hungary
| | - Zsuzsa Szabó
- Faculty of Science and Technology, Department of Biotechnology and Microbiology; University of Debrecen; Debrecen Hungary
| | - István Pócsi
- Faculty of Science and Technology, Department of Biotechnology and Microbiology; University of Debrecen; Debrecen Hungary
| |
Collapse
|
36
|
Katz ME, Buckland R, Hunter CC, Todd RB. Distinct roles for the p53-like transcription factor XprG and autophagy genes in the response to starvation. Fungal Genet Biol 2015; 83:10-18. [DOI: 10.1016/j.fgb.2015.08.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 08/13/2015] [Accepted: 08/17/2015] [Indexed: 12/21/2022]
|
37
|
Emri T, Szarvas V, Orosz E, Antal K, Park H, Han KH, Yu JH, Pócsi I. Core oxidative stress response in Aspergillus nidulans. BMC Genomics 2015; 16:478. [PMID: 26115917 PMCID: PMC4482186 DOI: 10.1186/s12864-015-1705-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 06/15/2015] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND The b-Zip transcription factor AtfA plays a key role in regulating stress responses in the filamentous fungus Aspergillus nidulans. To identify the core regulons of AtfA, we examined genome-wide expression changes caused by various stresses in the presence/absence of AtfA using A. nidulans microarrays. We also intended to address the intriguing question regarding the existence of core environmental stress response in this important model eukaryote. RESULTS Examination of the genome wide expression changes caused by five different oxidative stress conditions in wild type and the atfA null mutant has identified a significant number of stereotypically regulated genes (Core Oxidative Stress Response genes). The deletion of atfA increased the oxidative stress sensitivity of A. nidulans and affected mRNA accumulation of several genes under both unstressed and stressed conditions. The numbers of genes under the AtfA control appear to be specific to a stress-type. We also found that both oxidative and salt stresses induced expression of some secondary metabolite gene clusters and the deletion of atfA enhanced the stress responsiveness of additional clusters. Moreover, certain clusters were down-regulated by the stresses tested. CONCLUSION Our data suggest that the observed co-regulations were most likely consequences of the overlapping physiological effects of the stressors and not of the existence of a general environmental stress response. The function of AtfA in governing various stress responses is much smaller than anticipated and/or other regulators may play a redundant or overlapping role with AtfA. Both stress inducible and stress repressive regulations of secondary metabolism seem to be frequent features in A. nidulans.
Collapse
Affiliation(s)
- Tamás Emri
- Department of Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, P.O. Box 63, H-4032, Debrecen, Hungary.
| | - Vera Szarvas
- Department of Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, P.O. Box 63, H-4032, Debrecen, Hungary.
| | - Erzsébet Orosz
- Department of Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, P.O. Box 63, H-4032, Debrecen, Hungary.
| | - Károly Antal
- Department of Zoology, Faculty of Sciences, Eszterházy Károly College, Eszterházy út 1, H-3300, Eger, Hungary.
| | - HeeSoo Park
- Department of Bacteriology, University of Wisconsin, 1550 Linden Dr, Madison, WI, 53706, USA.
| | - Kap-Hoon Han
- Department of Pharmaceutical Engineering, Woosuk University, 565-701, Wanju, Republic of Korea.
| | - Jae-Hyuk Yu
- Department of Bacteriology, University of Wisconsin, 1550 Linden Dr, Madison, WI, 53706, USA.
| | - István Pócsi
- Department of Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, P.O. Box 63, H-4032, Debrecen, Hungary.
| |
Collapse
|
38
|
Albright JC, Henke MT, Soukup AA, McClure RA, Thomson RJ, Keller NP, Kelleher NL. Large-scale metabolomics reveals a complex response of Aspergillus nidulans to epigenetic perturbation. ACS Chem Biol 2015; 10:1535-41. [PMID: 25815712 DOI: 10.1021/acschembio.5b00025] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The microbial world offers a rich source of bioactive compounds for those able to sift through it. Technologies capable of quantitatively detecting natural products while simultaneously identifying known compounds would expedite the search for new pharmaceutical leads. Prior efforts have targeted histone deacetylases in fungi to globally activate the production of new secondary metabolites, yet no study has directly assessed its effects with minimal bias at the metabolomic level. Using untargeted metabolomics, we monitored changes in >1000 small molecules secreted from the model fungus, Aspergillus nidulans, following genetic or chemical reductions in histone deacetylase activity (HDACi). Through quantitative, differential analyses, we found that nearly equal numbers of compounds were up- and down-regulated by >100 fold. We detected products from both known and unknown biosynthetic pathways and discovered that A. nidulans is capable of producing fellutamides, proteasome inhibitors whose expression was induced by ∼100 fold or greater upon HDACi. This work adds momentum to an "omics"-driven resurgence in natural products research, where direct detection replaces bioactivity as the primary screen for new pharmacophores.
Collapse
Affiliation(s)
- Jessica C. Albright
- Department of Chemistry, ‡Department of Molecular Biosciences, §Feinberg School of Medicine, Northwestern University, Evanston, Illinois 60208, United States
- Department of Genetics, ⊥Department of Bacteriology, #Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, Wisconsin 53706, United States
| | - Matthew T. Henke
- Department of Chemistry, ‡Department of Molecular Biosciences, §Feinberg School of Medicine, Northwestern University, Evanston, Illinois 60208, United States
- Department of Genetics, ⊥Department of Bacteriology, #Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, Wisconsin 53706, United States
| | - Alexandra A. Soukup
- Department of Chemistry, ‡Department of Molecular Biosciences, §Feinberg School of Medicine, Northwestern University, Evanston, Illinois 60208, United States
- Department of Genetics, ⊥Department of Bacteriology, #Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, Wisconsin 53706, United States
| | - Ryan A. McClure
- Department of Chemistry, ‡Department of Molecular Biosciences, §Feinberg School of Medicine, Northwestern University, Evanston, Illinois 60208, United States
- Department of Genetics, ⊥Department of Bacteriology, #Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, Wisconsin 53706, United States
| | - Regan J. Thomson
- Department of Chemistry, ‡Department of Molecular Biosciences, §Feinberg School of Medicine, Northwestern University, Evanston, Illinois 60208, United States
- Department of Genetics, ⊥Department of Bacteriology, #Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, Wisconsin 53706, United States
| | - Nancy P. Keller
- Department of Chemistry, ‡Department of Molecular Biosciences, §Feinberg School of Medicine, Northwestern University, Evanston, Illinois 60208, United States
- Department of Genetics, ⊥Department of Bacteriology, #Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, Wisconsin 53706, United States
| | - Neil L. Kelleher
- Department of Chemistry, ‡Department of Molecular Biosciences, §Feinberg School of Medicine, Northwestern University, Evanston, Illinois 60208, United States
- Department of Genetics, ⊥Department of Bacteriology, #Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, Wisconsin 53706, United States
| |
Collapse
|
39
|
Ellström M, Shah F, Johansson T, Ahrén D, Persson P, Tunlid A. The carbon starvation response of the ectomycorrhizal fungus Paxillus involutus. FEMS Microbiol Ecol 2015; 91:fiv027. [PMID: 25778509 PMCID: PMC4434801 DOI: 10.1093/femsec/fiv027] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Revised: 01/02/2015] [Accepted: 03/10/2015] [Indexed: 11/19/2022] Open
Abstract
The amounts of carbon allocated to the fungal partner in ectomycorrhizal associations can vary substantially depending on the plant growth and the soil nutrient conditions, and the fungus may frequently be confronted with limitations in carbon. We used chemical analysis and transcriptome profiling to examine the physiological response of the ectomycorrhizal fungus Paxillus involutus to carbon starvation during axenic cultivation. Carbon starvation induced a decrease in the biomass. Concomitantly, ammonium, cell wall material (chitin) and proteolytic enzymes were released into the medium, which suggest autolysis. Compared with the transcriptome of actively growing hyphae, about 45% of the transcripts analyzed were differentially regulated during C-starvation. Induced during starvation were transcripts encoding extracellular enzymes such as peptidases, chitinases and laccases. In parallel, transcripts of N-transporters were upregulated, which suggest that some of the released nitrogen compounds were re-assimilated by the mycelium. The observed changes suggest that the carbon starvation response in P. involutus is associated with complex cellular changes that involves autolysis, recycling of intracellular compounds by autophagy and reabsorption of the extracellular released material. The study provides molecular markers that can be used to examine the role of autolysis for the turnover and survival of the ectomycorrhizal mycelium in soils.
Collapse
Affiliation(s)
- Magnus Ellström
- Microbial Ecology, Department of Biology, Lund University, Ecology Building, SE 223 62 Lund, Sweden Centre for Environmental and Climate Research (CEC), Lund University, Ecology Building, SE 223 62 Lund, Sweden
| | - Firoz Shah
- Microbial Ecology, Department of Biology, Lund University, Ecology Building, SE 223 62 Lund, Sweden
| | - Tomas Johansson
- Microbial Ecology, Department of Biology, Lund University, Ecology Building, SE 223 62 Lund, Sweden
| | - Dag Ahrén
- Microbial Ecology, Department of Biology, Lund University, Ecology Building, SE 223 62 Lund, Sweden BILS Bioinformatics Infrastructure for Life Sciences, Department of Biology, Lund University, Ecology Building, SE 223 62 Lund, Sweden
| | - Per Persson
- Microbial Ecology, Department of Biology, Lund University, Ecology Building, SE 223 62 Lund, Sweden Centre for Environmental and Climate Research (CEC), Lund University, Ecology Building, SE 223 62 Lund, Sweden
| | - Anders Tunlid
- Microbial Ecology, Department of Biology, Lund University, Ecology Building, SE 223 62 Lund, Sweden
| |
Collapse
|
40
|
Lopez-Moya F, Colom-Valiente MF, Martinez-Peinado P, Martinez-Lopez JE, Puelles E, Sempere-Ortells JM, Lopez-Llorca LV. Carbon and nitrogen limitation increase chitosan antifungal activity in Neurospora crassa and fungal human pathogens. Fungal Biol 2015; 119:154-69. [DOI: 10.1016/j.funbio.2014.12.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 12/04/2014] [Accepted: 12/08/2014] [Indexed: 01/06/2023]
|
41
|
Complete genome sequence and transcriptomics analyses reveal pigment biosynthesis and regulatory mechanisms in an industrial strain, Monascus purpureus YY-1. Sci Rep 2015; 5:8331. [PMID: 25660389 PMCID: PMC4321180 DOI: 10.1038/srep08331] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 01/19/2015] [Indexed: 12/20/2022] Open
Abstract
Monascus has been used to produce natural colorants and food supplements for more than one thousand years, and approximately more than one billion people eat Monascus-fermented products during their daily life. In this study, using next-generation sequencing and optical mapping approaches, a 24.1-Mb complete genome of an industrial strain, Monascus purpureus YY-1, was obtained. This genome consists of eight chromosomes and 7,491 genes. Phylogenetic analysis at the genome level provides convincing evidence for the evolutionary position of M. purpureus. We provide the first comprehensive prediction of the biosynthetic pathway for Monascus pigment. Comparative genomic analyses show that the genome of M. purpureus is 13.6–40% smaller than those of closely related filamentous fungi and has undergone significant gene losses, most of which likely occurred during its specialized adaptation to starch-based foods. Comparative transcriptome analysis reveals that carbon starvation stress, resulting from the use of relatively low-quality carbon sources, contributes to the high yield of pigments by repressing central carbon metabolism and augmenting the acetyl-CoA pool. Our work provides important insights into the evolution of this economically important fungus and lays a foundation for future genetic manipulation and engineering of this strain.
Collapse
|
42
|
Systems approaches to predict the functions of glycoside hydrolases during the life cycle of Aspergillus niger using developmental mutants ∆brlA and ∆flbA. PLoS One 2015; 10:e0116269. [PMID: 25629352 PMCID: PMC4309609 DOI: 10.1371/journal.pone.0116269] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2014] [Accepted: 12/05/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The filamentous fungus Aspergillus niger encounters carbon starvation in nature as well as during industrial fermentations. In response, regulatory networks initiate and control autolysis and sporulation. Carbohydrate-active enzymes play an important role in these processes, for example by modifying cell walls during spore cell wall biogenesis or in cell wall degradation connected to autolysis. RESULTS In this study, we used developmental mutants (ΔflbA and ΔbrlA) which are characterized by an aconidial phenotype when grown on a plate, but also in bioreactor-controlled submerged cultivations during carbon starvation. By comparing the transcriptomes, proteomes, enzyme activities and the fungal cell wall compositions of a wild type A. niger strain and these developmental mutants during carbon starvation, a global overview of the function of carbohydrate-active enzymes is provided. Seven genes encoding carbohydrate-active enzymes, including cfcA, were expressed during starvation in all strains; they may encode enzymes involved in cell wall recycling. Genes expressed in the wild-type during starvation, but not in the developmental mutants are likely involved in conidiogenesis. Eighteen of such genes were identified, including characterized sporulation-specific chitinases and An15g02350, member of the recently identified carbohydrate-active enzyme family AA11. Eight of the eighteen genes were also expressed, independent of FlbA or BrlA, in vegetative mycelium, indicating that they also have a role during vegetative growth. The ΔflbA strain had a reduced specific growth rate, an increased chitin content of the cell wall and specific expression of genes that are induced in response to cell wall stress, indicating that integrity of the cell wall of strain ΔflbA is reduced. CONCLUSION The combination of the developmental mutants ΔflbA and ΔbrlA resulted in the identification of enzymes involved in cell wall recycling and sporulation-specific cell wall modification, which contributes to understanding cell wall remodeling mechanisms during development.
Collapse
|
43
|
Spitzmüller Z, Kwon NJ, Szilágyi M, Keserű J, Tóth V, Yu JH, Pócsi I, Emri T. γ-Glutamyl transpeptidase (GgtA) of Aspergillus nidulans is not necessary for bulk degradation of glutathione. Arch Microbiol 2014; 197:285-97. [PMID: 25519188 DOI: 10.1007/s00203-014-1057-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Revised: 10/27/2014] [Accepted: 10/28/2014] [Indexed: 12/31/2022]
Abstract
Aspergillus nidulans exhibited high γ-glutamyl transpeptidase (γGT) activity in both carbon-starved and carbon-limited cultures. Glucose repressed, but casein peptone increased γGT production. Null mutation of creA did not influence γGT formation, but the functional meaB was necessary for the γGT induction. Deletion of the AN10444 gene (ggtA) completely eliminated the γGT activity, and the mRNA levels of ggtA showed strong correlation with the observed γGT activities. While ggtA does not contain a canonical signal sequence, the γGT activity was detectable both in the fermentation broth and in the hyphae. Deletion of the ggtA gene did not prevent the depletion of glutathione observed in carbon-starved and carbon-limited cultures. Addition of casein peptone to carbon-starved cultures lowered the formation of reactive species (RS). Deletion of ggtA could hinder this decrease and resulted in elevated RS formation. This effect of γGT on redox homeostasis may explain the reduced cleistothecia formation of ΔggtA strains in surface cultures.
Collapse
Affiliation(s)
- Zsolt Spitzmüller
- Department of Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, Debrecen, H4032, Hungary
| | | | | | | | | | | | | | | |
Collapse
|
44
|
Zhang F, Guo Z, Zhong H, Wang S, Yang W, Liu Y, Wang S. RNA-Seq-based transcriptome analysis of aflatoxigenic Aspergillus flavus in response to water activity. Toxins (Basel) 2014; 6:3187-207. [PMID: 25421810 PMCID: PMC4247253 DOI: 10.3390/toxins6113187] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 10/27/2014] [Accepted: 11/13/2014] [Indexed: 01/06/2023] Open
Abstract
Aspergillus flavus is one of the most important producers of carcinogenic aflatoxins in crops, and the effect of water activity (aw) on growth and aflatoxin production of A. flavus has been previously studied. Here we found the strains under 0.93 aw exhibited decreased conidiation and aflatoxin biosynthesis compared to that under 0.99 aw. When RNA-Seq was used to delineate gene expression profile under different water activities, 23,320 non-redundant unigenes, with an average length of 1297 bp, were yielded. By database comparisons, 19,838 unigenes were matched well (e-value < 10−5) with known gene sequences, and another 6767 novel unigenes were obtained by comparison to the current genome annotation of A. flavus. Based on the RPKM equation, 5362 differentially expressed unigenes (with |log2Ratio| ≥ 1) were identified between 0.99 aw and 0.93 aw treatments, including 3156 up-regulated and 2206 down-regulated unigenes, suggesting that A. flavus underwent an extensive transcriptome response during water activity variation. Furthermore, we found that the expression of 16 aflatoxin producing-related genes decreased obviously when water activity decreased, and the expression of 11 development-related genes increased after 0.99 aw treatment. Our data corroborate a model where water activity affects aflatoxin biosynthesis through increasing the expression of aflatoxin producing-related genes and regulating development-related genes.
Collapse
Affiliation(s)
- Feng Zhang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of the Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Zhenni Guo
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of the Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Hong Zhong
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of the Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Sen Wang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of the Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Weiqiang Yang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of the Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Yongfeng Liu
- Shenzhen Key Laboratory of Bioenergy, BGI-Shenzhen, Shenzhen 518083, China.
| | - Shihua Wang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of the Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| |
Collapse
|
45
|
van Munster JM, Daly P, Delmas S, Pullan ST, Blythe MJ, Malla S, Kokolski M, Noltorp ECM, Wennberg K, Fetherston R, Beniston R, Yu X, Dupree P, Archer DB. The role of carbon starvation in the induction of enzymes that degrade plant-derived carbohydrates in Aspergillus niger. Fungal Genet Biol 2014; 72:34-47. [PMID: 24792495 PMCID: PMC4217149 DOI: 10.1016/j.fgb.2014.04.006] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Revised: 03/21/2014] [Accepted: 04/18/2014] [Indexed: 11/06/2022]
Abstract
Fungi are an important source of enzymes for saccharification of plant polysaccharides and production of biofuels. Understanding of the regulation and induction of expression of genes encoding these enzymes is still incomplete. To explore the induction mechanism, we analysed the response of the industrially important fungus Aspergillus niger to wheat straw, with a focus on events occurring shortly after exposure to the substrate. RNA sequencing showed that the transcriptional response after 6h of exposure to wheat straw was very different from the response at 24h of exposure to the same substrate. For example, less than half of the genes encoding carbohydrate active enzymes that were induced after 24h of exposure to wheat straw, were also induced after 6h exposure. Importantly, over a third of the genes induced after 6h of exposure to wheat straw were also induced during 6h of carbon starvation, indicating that carbon starvation is probably an important factor in the early response to wheat straw. The up-regulation of the expression of a high number of genes encoding CAZymes that are active on plant-derived carbohydrates during early carbon starvation suggests that these enzymes could be involved in a scouting role during starvation, releasing inducing sugars from complex plant polysaccharides. We show, using proteomics, that carbon-starved cultures indeed release CAZymes with predicted activity on plant polysaccharides. Analysis of the enzymatic activity and the reaction products, indicates that these proteins are enzymes that can degrade various plant polysaccharides to generate both known, as well as potentially new, inducers of CAZymes.
Collapse
Affiliation(s)
- Jolanda M van Munster
- School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
| | - Paul Daly
- School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
| | - Stéphane Delmas
- School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
| | - Steven T Pullan
- School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
| | - Martin J Blythe
- Deep Seq, Faculty of Medicine and Health Sciences, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK.
| | - Sunir Malla
- Deep Seq, Faculty of Medicine and Health Sciences, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK.
| | - Matthew Kokolski
- School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
| | - Emelie C M Noltorp
- School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
| | - Kristin Wennberg
- School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
| | - Richard Fetherston
- School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
| | - Richard Beniston
- Biological Mass Spectrometry Facility biOMICS, University of Sheffield, Brook Hill Road, Sheffield S3 7HF, UK.
| | - Xiaolan Yu
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK.
| | - Paul Dupree
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK.
| | - David B Archer
- School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
| |
Collapse
|
46
|
High-yield recombinant xylanase production by Aspergillus nidulans under pyridoxine limitation. ACTA ACUST UNITED AC 2014; 41:1563-70. [DOI: 10.1007/s10295-014-1492-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 07/12/2014] [Indexed: 01/04/2023]
Abstract
Abstract
The present study investigated the limitation of pyridoxine on an Aspergillus nidulans culture that produces xylanase B (XynB) as a client enzyme and was unable to synthesize pyridoxine. This technique was used to limit cell growth and divert substrate to product formation for a surface grown culture that could be used in trickle bed reactors. It was observed that growth was limited when pyridoxine was absent, while enzyme production was unaffected. Enzyme production was 1,026 U after 480 h of continuous fermentation, which was similar to a culture that grew on medium with pyridoxine. Furthermore, the present study investigated the growth rate of A. nidulans with pyridoxine in the medium and determined the productivity of XynB production with and without pyridoxine. A maximum growth rate of 0.311/h was observed. The maximum XynB productivity of 21.14 U/g h was achieved when pyridoxine was not added to the medium.
Collapse
|
47
|
Characterization of the starvation-induced chitinase CfcA and α-1,3-glucanase AgnB of Aspergillus niger. Appl Microbiol Biotechnol 2014; 99:2209-23. [DOI: 10.1007/s00253-014-6062-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 08/25/2014] [Accepted: 08/29/2014] [Indexed: 10/24/2022]
|
48
|
Rúa J, de Castro C, de Arriaga D, García-Armesto MR, Busto F, del Valle P. Stress in Phycomyces blakesleeanus by glucose starvation and acetate growth: Response of the antioxidant system and reserve carbohydrates. Microbiol Res 2014; 169:788-93. [DOI: 10.1016/j.micres.2013.12.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Revised: 12/05/2013] [Accepted: 12/20/2013] [Indexed: 01/01/2023]
|
49
|
Kovács B, Hegedűs N, Bálint M, Szabó Z, Emri T, Kiss G, Antal M, Pócsi I, Leiter É. Penicillium antifungal protein (PAF) is involved in the apoptotic and autophagic processes of the producer Penicillium chrysogenum. Acta Microbiol Immunol Hung 2014; 61:379-88. [PMID: 25261948 DOI: 10.1556/amicr.61.2014.3.10] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
PAF, which is produced by the filamentous fungus Pencicillium chrysogenum, is a small antifungal protein, triggering ROS-mediated apoptotic cell death in Aspergillus nidulans. In this work, we provide information on the function of PAF in the host P. chrysogenum considering that carbon-starving cultures of the Δpaf mutant strain showed significantly reduced apoptosis rates in comparison to the wild-type (wt) strain. Moreover, the addition of PAF to the Δpaf strain resulted in a twofold increase in the apoptosis rate. PAF was also involved in the regulation of the autophagy machinery of this fungus, since several Saccharomyces cerevisiae autophagy-related ortholog genes, e.g. those of atg7, atg22 and tipA, were repressed in the deletion strain. This phenomenon was accompanied by the absence of autophagosomes in the Δpaf strain, even in old hyphae.
Collapse
Affiliation(s)
- Barbara Kovács
- 1 University of Debrecen Department of Microbial Biotechnology and Cell Biology, Faculty of Science and Technology Debrecen Hungary
| | - Nikoletta Hegedűs
- 1 University of Debrecen Department of Microbial Biotechnology and Cell Biology, Faculty of Science and Technology Debrecen Hungary
| | - Mihály Bálint
- 1 University of Debrecen Department of Microbial Biotechnology and Cell Biology, Faculty of Science and Technology Debrecen Hungary
| | - Zsuzsa Szabó
- 1 University of Debrecen Department of Microbial Biotechnology and Cell Biology, Faculty of Science and Technology Debrecen Hungary
| | - Tamás Emri
- 1 University of Debrecen Department of Microbial Biotechnology and Cell Biology, Faculty of Science and Technology Debrecen Hungary
| | - Gréta Kiss
- 2 University of Debrecen Department of Anatomy, Histology and Embriology, Faculty of Medicine Debrecen Hungary
| | - Miklós Antal
- 2 University of Debrecen Department of Anatomy, Histology and Embriology, Faculty of Medicine Debrecen Hungary
| | - István Pócsi
- 1 University of Debrecen Department of Microbial Biotechnology and Cell Biology, Faculty of Science and Technology Debrecen Hungary
| | - Éva Leiter
- 1 University of Debrecen Department of Microbial Biotechnology and Cell Biology, Faculty of Science and Technology Debrecen Hungary
| |
Collapse
|
50
|
Huang X, Chen M, Lu X, Li Y, Li X, Li JJ. Direct production of itaconic acid from liquefied corn starch by genetically engineered Aspergillus terreus. Microb Cell Fact 2014; 13:108. [PMID: 25162619 PMCID: PMC4145239 DOI: 10.1186/s12934-014-0108-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 07/22/2014] [Indexed: 01/01/2023] Open
Abstract
Background Itaconic acid is on the DOE (Department of Energy) top 12 list of biotechnologically produced building block chemicals and is produced commercially by Aspergillus terreus. However, the production cost of itaconic acid is too high to be economically competitive with the petrochemical-based products. Itaconic acid is generally produced from raw corn starch, including three steps: enzymatic hydrolysis of corn starch into a glucose-rich syrup by α-amylase and glucoamylase, fermentation, and recovery of itaconic acid. The whole process is very time-consuming and energy-intensive. Results In order to reduce the production cost, saccharification and fermentation were integrated into one step through overexpressing the glucoamylase gene in A. terreus under the control of the native PcitA promoter. The transformant XH61-5 produced higher itaconate titer from liquefied starch than WT. To further increase the titer by enhancing the secretion capacity of overexpressed glucoamylase, a stronger signal peptide was selected based on the major secreted protein ATEG_02176 (an acid phosphatase precursor) by A. terreus under the itaconate production conditions. Under the control of the stronger signal peptide, the transformant XH86-8 showed higher itaconate production level than XH61-5 from liquefied starch. The itaconate titer was further enhanced through a two-step process involving the vegetative and production phase, and the transformant XH86-8 produced comparable itaconate titer from liquefied starch to current one (~80 g/L) from saccharified starch hydrolysates in industry. The effects of the new signal peptide and the two-step process on itaconate production were investigated and discussed. Conclusions Itaconic acid could be efficiently produced from liquefied corn starch by overexpressing the glucoamylase gene in A. terreus, which will be helpful for constructing a highly efficient microbial cell factory for itaconate production and for further lowering the production cost of itaconic acid. Electronic supplementary material The online version of this article (doi:10.1186/s12934-014-0108-1) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
| | | | | | | | | | - Jian-Jun Li
- Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, No, 189 Songling Road, Qingdao 266101, China.
| |
Collapse
|