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Sakai K, Sato K, Kaneoke M, Kusumoto KI. Isolation and characterization of koji mold (Aspergillus oryzae) from nature in Niigata. J Biosci Bioeng 2024; 138:415-422. [PMID: 39227280 DOI: 10.1016/j.jbiosc.2024.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2024] [Revised: 08/01/2024] [Accepted: 08/10/2024] [Indexed: 09/05/2024]
Abstract
Koji mold (Aspergillus oryzae) is a key microorganism in brewing and fermentation in Japan. We isolated koji molds from the environment in Niigata Prefecture. Eighty-one environmental samples were placed on isolation medium made from steamed rice with wood ash and 36 Aspergillus section Flavi-like strains were obtained. Of those, 26 strains did not produce aflatoxin. We studied their morphology, sequence of ITS region, calmodulin gene, aflatoxin biosynthetic homologous gene cluster and α-amylase gene and fermentation-related enzyme activities. Furthermore, DNA-seq analysis of 14 strains from 26 non-aflatoxin producing strains were conducted and compared the three mycotoxin biosynthetic gene clusters (aflatoxin, cyclopiazonic acid, and aflatrem) and fermentation-related genes against those of reference strain A. oryzae RIB40. In some strains, gene sequences confirmed the absence of mycotoxin production, but differences in fermentation-related enzyme activities could not be explained well by amino acid substitutions. We classified the 26 isolates into 6 morphology types based on the appearance of colonies and mating types, and it was found that strains of the same morphology type had similar enzymatic profiles and gene sequences. Our results show that koji molds with various properties occur in the environment, and it will expand the possibilities of koji mold in industrial use.
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Affiliation(s)
- Kanae Sakai
- Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Keigo Sato
- Niigata Prefectural Sake Research Institute, 2-5932-133 Suido-cho, Chuo-ku, Niigata 951-8121, Japan
| | - Mitsuoki Kaneoke
- Niigata Prefectural Sake Research Institute, 2-5932-133 Suido-cho, Chuo-ku, Niigata 951-8121, Japan
| | - Ken-Ichi Kusumoto
- Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
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Han DM, Baek JH, Choi DG, Jeon MS, Eyun SI, Jeon CO. Comparative pangenome analysis of Aspergillus flavus and Aspergillus oryzae reveals their phylogenetic, genomic, and metabolic homogeneity. Food Microbiol 2024; 119:104435. [PMID: 38225047 DOI: 10.1016/j.fm.2023.104435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 11/17/2023] [Accepted: 11/25/2023] [Indexed: 01/17/2024]
Abstract
Aspergillus flavus and Aspergillus oryzae are closely related fungal species with contrasting roles in food safety and fermentation. To comprehensively investigate their phylogenetic, genomic, and metabolic characteristics, we conducted an extensive comparative pangenome analysis using complete, dereplicated genome sets for both species. Phylogenetic analyses, employing both the entirety of the identified single-copy orthologous genes and six housekeeping genes commonly used for fungal classification, did not reveal clear differentiation between A. flavus and A. oryzae genomes. Upon analyzing the aflatoxin biosynthesis gene clusters within the genomes, we observed that non-aflatoxin-producing strains were dispersed throughout the phylogenetic tree, encompassing both A. flavus and A. oryzae strains. This suggests that aflatoxin production is not a distinguishing trait between the two species. Furthermore, A. oryzae and A. flavus strains displayed remarkably similar genomic attributes, including genome sizes, gene contents, and G + C contents, as well as metabolic features and pathways. The profiles of CAZyme genes and secondary metabolite biosynthesis gene clusters within the genomes of both species further highlight their similarity. Collectively, these findings challenge the conventional differentiation of A. flavus and A. oryzae as distinct species and highlight their phylogenetic, genomic, and metabolic homogeneity, potentially indicating that they may indeed belong to the same species.
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Affiliation(s)
- Dong Min Han
- Department of Life Science, Chung-Ang University, Seoul 06974, Republic of Korea
| | - Ju Hye Baek
- Department of Life Science, Chung-Ang University, Seoul 06974, Republic of Korea
| | - Dae Gyu Choi
- Department of Life Science, Chung-Ang University, Seoul 06974, Republic of Korea
| | - Min-Seung Jeon
- Department of Life Science, Chung-Ang University, Seoul 06974, Republic of Korea
| | - Seong-Il Eyun
- Department of Life Science, Chung-Ang University, Seoul 06974, Republic of Korea
| | - Che Ok Jeon
- Department of Life Science, Chung-Ang University, Seoul 06974, Republic of Korea.
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Djenontin E, Costa JM, Mousavi B, Nguyen LDN, Guillot J, Delhaes L, Botterel F, Dannaoui E. The Molecular Identification and Antifungal Susceptibility of Clinical Isolates of Aspergillus Section Flavi from Three French Hospitals. Microorganisms 2023; 11:2429. [PMID: 37894087 PMCID: PMC10609271 DOI: 10.3390/microorganisms11102429] [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: 09/07/2023] [Revised: 09/20/2023] [Accepted: 09/22/2023] [Indexed: 10/29/2023] Open
Abstract
(1) Background: Aspergillus flavus is a cosmopolitan mold with medical, veterinary, and agronomic concerns. Its morphological similarity to other cryptic species of the Flavi section requires molecular identification techniques that are not routinely performed. For clinical isolates of Aspergillus section Flavi, we present the molecular identification, susceptibility to six antifungal agents, and clinical context of source patients. (2) Methods: One hundred forty fungal clinical isolates were included in the study. These isolates, recovered over a 15-year period (2001-2015), were identified based on their morphological characteristics as belonging to section Flavi. After the subculture, sequencing of a part of the β-tubulin and calmodulin genes was performed, and resistance to azole antifungals was screened on agar plates containing itraconazole and voriconazole. Minimum inhibitory concentrations were determined for 120 isolates by the European Committee on Antimicrobial Susceptibility Testing (EUCAST) broth microdilution method. (3) Results: Partial β-tubulin and calmodulin sequences analysis showed that 138/140 isolates were A. flavus sensu stricto, 1 isolate was A. parasiticus/sojae, and 1 was A. nomiae. Many of the isolates came from samples collected in the context of respiratory tract colonization. Among probable or proven aspergillosis, respiratory infections were the most frequent, followed by ENT infections. Antifungal susceptibility testing was available for isolates (n = 120, all A. flavus ss) from one hospital. The MIC range (geometric mean MIC) in mg/L was 0.5-8 (0.77), 0.5-8 (1.03), 0.125-2 (0.25), 0.03-2 (0.22), 0.25-8 (1.91), and 0.03-0.125 (0.061) for voriconazole, isavuconazole, itraconazole, posaconazole, amphotericin B, and caspofungin, respectively. Two (1.67%) isolates showed resistance to isavuconazole according to current EUCAST breakpoints with MICs at 8 mg/L for isavuconazole and voriconazole. One of these two isolates was also resistant to itraconazole with MIC at 2 mg/L. (4) Conclusions: The present characterization of a large collection of Aspergillus belonging to the Flavi section confirmed that A. flavus ss is the predominant species. It is mainly implicated in respiratory and ENT infections. The emergence of resistance highlights the need to perform susceptibility tests on section Flavi isolates.
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Affiliation(s)
- Elie Djenontin
- Dynamyc UPEC, EnvA, USC Anses, Faculté de Médecine de Créteil, 94010 Créteil, France; (E.D.); (B.M.); (F.B.)
- Service de Parasitologie-Mycologie, Hôpital Universitaire Mondor, AP-HP, 8 Rue du Général Sarrail, 94010 Créteil, France
| | - Jean-Marc Costa
- Laboratoire CERBA, 11 Rue de l’Équerre, 95310 Saint-Ouen-l’Aumône, France;
| | - Bita Mousavi
- Dynamyc UPEC, EnvA, USC Anses, Faculté de Médecine de Créteil, 94010 Créteil, France; (E.D.); (B.M.); (F.B.)
| | | | - Jacques Guillot
- Unité pédagogique de Dermatologie, Parasitologie, Mycologie, Ecole Nationale Vétérinaire Agroalimentaire et de l’Alimentation Nantes Atlantique, Oniris, 44300 Nantes, France;
| | - Laurence Delhaes
- Laboratoire de Parasitologie-Mycologie, CNR des Aspergilloses Chroniques—CHU de Bordeaux, INSERM U1045—Univ. Bordeaux, 33000 Bordeaux, France;
| | - Françoise Botterel
- Dynamyc UPEC, EnvA, USC Anses, Faculté de Médecine de Créteil, 94010 Créteil, France; (E.D.); (B.M.); (F.B.)
- Service de Parasitologie-Mycologie, Hôpital Universitaire Mondor, AP-HP, 8 Rue du Général Sarrail, 94010 Créteil, France
| | - Eric Dannaoui
- Dynamyc UPEC, EnvA, USC Anses, Faculté de Médecine de Créteil, 94010 Créteil, France; (E.D.); (B.M.); (F.B.)
- Faculté de Médecine, Université Paris Cité, 75006 Paris, France
- Unité de Parasitologie-Mycologie, Hôpital Necker Enfants Malades, AP-HP, 149 Rue de Sèvres, 75015 Paris, France
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Chang PK, Hua SST. Are Current Aspergillus sojae Strains Originated from a Native Aflatoxigenic Aspergillus Species Population Also Present in California? MYCOBIOLOGY 2023; 51:139-147. [PMID: 37359951 PMCID: PMC10288891 DOI: 10.1080/12298093.2023.2217495] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 05/18/2023] [Accepted: 05/19/2023] [Indexed: 06/28/2023]
Abstract
Aspergillus sojae has long been considered a domesticated strain of Aspergillus parasiticus. This study delineated relationships among the two species and an Aspergillus PWE36 isolate. Of 25 examined clustered aflatoxin genes of PWE36, 20 gene sequences were identical to those of A. sojae, but all had variations to those of A. parasiticus. Additionally, PWE36 developmental genes of conidiation and sclerotial formation, overall, shared higher degrees of nucleotide sequence identity with A. sojae genes than with A. parasiticus genes. Examination of defective cyclopiazonic acid gene clusters revealed that the PWE36 deletion pattern was identical only to those of A. sojae. Using A. sojae SMF134 genome sequence as a reference, visualization of locally collinear blocks indicated that PWE36 shared higher genome sequence homologies with A. sojae than with A. parasiticus. Phylogenetic inference based on genome-wide single nucleotide polymorphisms (SNPs) and total SNP counts showed that A. sojae strains formed a monophyletic clade and were clonal. Two (Argentinian and Ugandan) A. parasiticus isolates but not including an Ethiopian isolate formed a monophyletic clade, which showed that A. parasiticus population is genetically diverse and distant to A. sojae. PWE36 and A. sojae shared a most recent common ancestor (MRCA). The estimated divergence time for PWE36 and A. sojae was about 0.4 mya. Unlike Aspergillus oryzae, another koji mold that includes genetically diverse populations, the findings that current A. sojae strains formed a monophyletic group and shared the MRCA with PWE36 allow A. sojae to be continuously treated as a species for food safety reasons.
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Affiliation(s)
- Perng-Kuang Chang
- Southern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, New Orleans, LA, USA
| | - Sui Sheng T. Hua
- Western Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, Albany, CA, USA
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Abastabar M, Shabanzadeh S, Valadan R, Mayahi S, Haghani I, Khojasteh S, Nargesi S, Seyedmousavi S, Hedayati MT. Development of RFLP method for rapid differentiation of Aspergillus flavus and Aspergillus oryzae, two species with high importance in clinical and food microbiology. J Mycol Med 2022; 32:101274. [DOI: 10.1016/j.mycmed.2022.101274] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 02/18/2022] [Accepted: 03/07/2022] [Indexed: 01/11/2023]
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6
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Daba GM, Mostafa FA, Elkhateeb WA. The ancient koji mold (Aspergillus oryzae) as a modern biotechnological tool. BIORESOUR BIOPROCESS 2021; 8:52. [PMID: 38650252 PMCID: PMC10992763 DOI: 10.1186/s40643-021-00408-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Accepted: 06/16/2021] [Indexed: 01/07/2023] Open
Abstract
Aspergillus oryzae (A. oryzae) is a filamentous micro-fungus that is used from centuries in fermentation of different foods in many countries all over the world. This valuable fungus is also a rich source of many bioactive secondary metabolites. Moreover, A. oryzae has a prestigious secretory system that allows it to secrete high concentrations of proteins into its culturing medium, which support its use as biotechnological tool in veterinary, food, pharmaceutical, and industrial fields. This review aims to highlight the significance of this valuable fungus in food industry, showing its generosity in production of nutritional and bioactive metabolites that enrich food fermented by it. Also, using A. oryzae as a biotechnological tool in the field of enzymes production was described. Furthermore, domestication, functional genomics, and contributions of A. oryzae in functional production of human pharmaceutical proteins were presented. Finally, future prospects in order to get more benefits from A. oryzae were discussed.
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Affiliation(s)
- Ghoson M Daba
- Chemistry of Natural and Microbial Products Department, Pharmaceutical Industries Researches Division, National Research Centre, El Buhouth Street, Dokki, Giza, 12311, Egypt.
| | - Faten A Mostafa
- Chemistry of Natural and Microbial Products Department, Pharmaceutical Industries Researches Division, National Research Centre, El Buhouth Street, Dokki, Giza, 12311, Egypt.
| | - Waill A Elkhateeb
- Chemistry of Natural and Microbial Products Department, Pharmaceutical Industries Researches Division, National Research Centre, El Buhouth Street, Dokki, Giza, 12311, Egypt
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7
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Moore GG. Practical considerations will ensure the continued success of pre-harvest biocontrol using non-aflatoxigenic Aspergillus flavus strains. Crit Rev Food Sci Nutr 2021; 62:4208-4225. [PMID: 33506687 DOI: 10.1080/10408398.2021.1873731] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
There is an important reason for the accelerated use of non-aflatoxigenic Aspergillus flavus to mitigate pre-harvest aflatoxin contamination… it effectively addresses the imperative need for safer food and feed. Now that we have decades of proof of the effectiveness of A. flavus as biocontrol, it is time to improve several aspects of this strategy. If we are to continue relying heavily on this form of aflatoxin mitigation, there are considerations we must acknowledge, and actions we must take, to ensure that we are best wielding this strategy to our advantage. These include its: (1) potential to produce other mycotoxins, (2) persistence in the field in light of several ecological factors, (3) its reproductive and genetic stability, (4) the mechanism(s) employed that allow it to elicit control over aflatoxigenic strains and species of agricultural importance and (5) supplemental alternatives that increase its effectiveness. There is a need to be consistent, practical and thoughtful when it comes to implementing this method of mycotoxin mitigation since these fungi are living organisms that have been adapting, evolving and surviving on this planet for tens-of-millions of years. This document will serve as a critical review of the literature regarding pre-harvest A. flavus biocontrol and will discuss opportunities for improvements.
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Affiliation(s)
- Geromy G Moore
- United States Department of Agriculture, Agricultural Research Service, New Orleans, USA
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8
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Watarai N, Yamamoto N, Sawada K, Yamada T. Evolution of Aspergillus oryzae before and after domestication inferred by large-scale comparative genomic analysis. DNA Res 2020; 26:465-472. [PMID: 31755931 PMCID: PMC6993814 DOI: 10.1093/dnares/dsz024] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Accepted: 11/21/2019] [Indexed: 12/22/2022] Open
Abstract
Aspergillus oryzae is an industrially useful species, of which various strains have been identified; however, their genetic relationships remain unclear. A. oryzae was previously thought to be asexual and unable to undergo crossbreeding. However, recent studies revealed the sexual reproduction of Aspergillus flavus, a species closely related to A. oryzae. To investigate potential sexual reproduction in A. oryzae and evolutionary history among A. oryzae and A. flavus strains, we assembled 82 draft genomes of A. oryzae strains used practically. The phylogenetic tree of concatenated genes confirmed that A. oryzae was monophyletic and nested in one of the clades of A. flavus but formed several clades with different genomic structures. Our results suggest that A. oryzae strains have undergone multiple inter-genomic recombination events between A. oryzae ancestors, although sexual recombination among domesticated species did not appear to have occurred during the domestication process, at least in the past few decades. Through inter- and intra-cladal comparative analysis, we found that evolutionary pressure induced by the domestication of A. oryzae appears to selectively cause non-synonymous and gap mutations in genes involved in fermentation characteristics, as well as intra-genomic rearrangements, with the conservation of industrially useful catalytic enzyme-encoding genes.
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Affiliation(s)
- Naoki Watarai
- Department of Life Science and Technology, Tokyo Institute of Technology, Tokyo 152-8550, Japan
| | - Nozomi Yamamoto
- Department of Life Science and Technology, Tokyo Institute of Technology, Tokyo 152-8550, Japan
| | | | - Takuji Yamada
- Department of Life Science and Technology, Tokyo Institute of Technology, Tokyo 152-8550, Japan
- To whom correspondence should be addressed. Tel. +81 3 5734 3591. Fax. +81 3 5734 3591.
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9
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Chang P. Genome‐wide nucleotide variation distinguishesAspergillus flavusfromAspergillus oryzaeand helps to reveal origins of atoxigenicA. flavusbiocontrol strains. J Appl Microbiol 2019; 127:1511-1520. [DOI: 10.1111/jam.14419] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 08/13/2019] [Accepted: 08/15/2019] [Indexed: 11/30/2022]
Affiliation(s)
- P.‐K. Chang
- Southern Regional Research Center Agricultural Research Service U. S. Department of Agriculture New Orleans LA USA
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Ayofemi Olalekan Adeyeye S. Aflatoxigenic fungi and mycotoxins in food: a review. Crit Rev Food Sci Nutr 2019; 60:709-721. [DOI: 10.1080/10408398.2018.1548429] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Samuel Ayofemi Olalekan Adeyeye
- Department for Management of Science and Technology Development, Ton Duc Thang University, Ho Chi Minh City, Vietnam
- Faculty of Environment and Labour Safety, Ton Duc Thang University, Ho Chi Minh City, Vietnam
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Frisvad JC, Møller LLH, Larsen TO, Kumar R, Arnau J. Safety of the fungal workhorses of industrial biotechnology: update on the mycotoxin and secondary metabolite potential of Aspergillus niger, Aspergillus oryzae, and Trichoderma reesei. Appl Microbiol Biotechnol 2018; 102:9481-9515. [PMID: 30293194 PMCID: PMC6208954 DOI: 10.1007/s00253-018-9354-1] [Citation(s) in RCA: 194] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 08/28/2018] [Accepted: 08/29/2018] [Indexed: 12/11/2022]
Abstract
This review presents an update on the current knowledge of the secondary metabolite potential of the major fungal species used in industrial biotechnology, i.e., Aspergillus niger, Aspergillus oryzae, and Trichoderma reesei. These species have a long history of safe use for enzyme production. Like most microorganisms that exist in a challenging environment in nature, these fungi can produce a large variety and number of secondary metabolites. Many of these compounds present several properties that make them attractive for different industrial and medical applications. A description of all known secondary metabolites produced by these species is presented here. Mycotoxins are a very limited group of secondary metabolites that can be produced by fungi and that pose health hazards in humans and other vertebrates when ingested in small amounts. Some mycotoxins are species-specific. Here, we present scientific basis for (1) the definition of mycotoxins including an update on their toxicity and (2) the clarity on misclassification of species and their mycotoxin potential reported in literature, e.g., A. oryzae has been wrongly reported as an aflatoxin producer, due to misclassification of Aspergillus flavus strains. It is therefore of paramount importance to accurately describe the mycotoxins that can potentially be produced by a fungal species that is to be used as a production organism and to ensure that production strains are not capable of producing mycotoxins during enzyme production. This review is intended as a reference paper for authorities, companies, and researchers dealing with secondary metabolite assessment, risk evaluation for food or feed enzyme production, or considerations on the use of these species as production hosts.
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Affiliation(s)
- Jens C Frisvad
- Department of Biotechnology and Biomedicine (DTU Bioengineering), Technical University of Denmark, Søltofts Plads, B. 221, 2800, Kongens Lyngby, Denmark.
| | - Lars L H Møller
- Department of Product Safety, Novozymes A/S, Krogshoejvej 36, 2880, Bagsvaerd, Denmark
| | - Thomas O Larsen
- Department of Biotechnology and Biomedicine (DTU Bioengineering), Technical University of Denmark, Søltofts Plads, B. 221, 2800, Kongens Lyngby, Denmark
| | - Ravi Kumar
- Department of Genomics and Bioinformatics, Novozymes Inc., 1445 Drew Ave., Davis, CA, 95618, USA
| | - José Arnau
- Department of Fungal Strain Technology and Strain Approval Support, Novozymes A/S, Krogshoejvej 36, 2880, Bagsvaerd, Denmark
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12
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Hua SST, Parfitt DE, Sarreal SBL, Lee BG, Wood DF. First report of an atypical new Aspergillus parasiticus isolates with nucleotide insertion in aflR gene resembling to A. sojae. Mycotoxin Res 2018; 34:151-157. [PMID: 29464607 DOI: 10.1007/s12550-018-0309-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 02/01/2018] [Accepted: 02/06/2018] [Indexed: 11/30/2022]
Abstract
Aflatoxins are toxic and carcinogenic secondary metabolites produced primarily by the filamentous fungi Aspergillus flavus and Aspergillus parasiticus and cause toxin contamination in food chain worldwide. Aspergillus oryzae and Aspergillus sojae are highly valued as koji molds in the traditional preparation of fermented foods, such as miso, sake, and shoyu. Koji mold species are generally perceived of as being nontoxigenic and are generally recognized as safe (GRAS). Fungal isolates were collected from a California orchard and a few were initially identified to be A. sojae using β-tubulin gene sequences blasted against NCBI data base. These new isolates all produced aflatoxins B1, B2, G1, and G2 and were named as Pistachio Winter Experiment (PWE) strains. Thus, it is very important to further characterize these strains for food safety purposes. The full length of aflR gene of these new isolates was sequenced. Comparison of aflR DNA sequences of PWE, A. parasiticus and A. sojae, showed that the aflatoxigenic PWE strains had the six base insertion (CTCATG) similar to domesticated A. sojae, but a pre-termination codon TGA at nucleotide positions 1153-1155 was absent due to a nucleotide codon change from T to C. Colony morphology and scanning microscopic imaging of spore surfaces showed similarity of PWE strains to both A. parasiticus and A. sojae. Concordance analysis of multi locus DNA sequences indicated that PWE strains were closely linked between A. parasiticus and A. sojae. The finding documented the first report that such unique strains have been found in North America and in the world.
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Affiliation(s)
- Sui Sheng T Hua
- US Department of Agriculture, Agricultural Research Service, Western Regional Research Center, 800 Buchanan Street, Albany, CA, 94710, USA.
| | - Dan E Parfitt
- Department of Plant Sciences, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA
| | - Siov Bouy L Sarreal
- US Department of Agriculture, Agricultural Research Service, Western Regional Research Center, 800 Buchanan Street, Albany, CA, 94710, USA
| | - Bertram G Lee
- US Department of Agriculture, Agricultural Research Service, Western Regional Research Center, 800 Buchanan Street, Albany, CA, 94710, USA
| | - Delilah F Wood
- US Department of Agriculture, Agricultural Research Service, Western Regional Research Center, 800 Buchanan Street, Albany, CA, 94710, USA
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LAMP-based group specific detection of aflatoxin producers within Aspergillus section Flavi in food raw materials, spices, and dried fruit using neutral red for visible-light signal detection. Int J Food Microbiol 2017; 266:241-250. [PMID: 29272724 DOI: 10.1016/j.ijfoodmicro.2017.12.013] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 12/13/2017] [Accepted: 12/14/2017] [Indexed: 01/10/2023]
Abstract
Aflatoxins can be produced by 21 species within sections Flavi (16 species), Ochraceorosei (2), and Nidulantes (3) of the fungal genus Aspergillus. They pose risks to human and animal health due to high toxicity and carcinogenicity. Detecting aflatoxin producers can help to assess toxicological risks associated with contaminated commodities. Species specific molecular assays (PCR and LAMP) are available for detection of major producers, but fail to detect species of minor importance. To enable rapid and sensitive detection of several aflatoxin producing species in a single analysis, a nor1 gene-specific LAMP assay was developed. Specificity testing showed that among 128 fungal species from 28 genera, 15 aflatoxigenic species in section Flavi were detected, including synonyms of A. flavus and A. parasiticus. No cross reactions were found with other tested species. The detection limit of the assay was 9.03pg of A. parasiticus genomic DNA per reaction. Visual detection of positive LAMP reactions under daylight conditions was facilitated using neutral red to allow unambiguous distinction between positive and negative assay results. Application of the assay to the detection of A. parasiticus conidia revealed a detection limit of 211 conidia per reaction after minimal sample preparation. The usefulness of the assay was demonstrated in the analysis of aflatoxinogenic species in samples of rice, nuts, raisins, dried figs, as well as powdered spices. Comparison of LAMP results with presence/absence of aflatoxins and aflatoxin producing fungi in 50 rice samples showed good correlation between these parameters. Our study suggests that the developed LAMP assay is a rapid, sensitive and user-friendly tool for surveillance and quality control in our food industry.
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14
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Karahalil E, Demirel F, Evcan E, Germeç M, Tari C, Turhan I. Microparticle-enhanced polygalacturonase production by wild type Aspergillus sojae. 3 Biotech 2017; 7:361. [PMID: 28979834 DOI: 10.1007/s13205-017-1004-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 09/26/2017] [Indexed: 11/28/2022] Open
Abstract
Polygalacturonases (PGs), an important industrial enzyme group classified under depolymerases, catalyze the hydrolytic cleavage of the polygalacturonic acid chain through the introduction of water across the oxygen bridge. In order to produce and increase the concentration of this enzyme group in fermentation processes, a new approach called microparticle cultivation, a promising and remarkable method, has been used. The aim of this study was to increase the PG activity of Aspergillus sojae using aluminum oxide (Al2O3) as microparticles in shake flask fermentation medium. Results indicated that the highest PG activity of 34.55 ± 0.5 U/ml was achieved with the addition of 20 g/L of Al2O3 while the lowest activity of 15.20 ± 0.2 U/mL was obtained in the presence of 0.1 g/L of Al2O3. In fermentation without microparticles as control, the activity was 15.64 ± 3.3 U/mL. Results showed that the maximum PG activity was 2.2-fold higher than control. Additionally, smaller pellets formed with the addition of Al2O3 where the lowest pellet diameter was 955.1 µm when 10 g/L of the microparticle was used. Also, it was noticed that biomass concentration gradually increased with increasing microparticle concentration in the fermentation media. Consequently, the PG activity was significantly increased in microparticle-enhanced shake flask fermentation. In fact, these promising preliminary data can be of significance to improve the enzyme activity in large-scale bioreactors.
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Affiliation(s)
- Ercan Karahalil
- Department of Food Engineering, Faculty of Engineering, Akdeniz University, 07058 Antalya, Turkey
| | - Fadime Demirel
- Department of Food Engineering, Faculty of Engineering, Akdeniz University, 07058 Antalya, Turkey
| | - Ezgi Evcan
- Department of Food Engineering, Izmir Institute of Technology, Gulbahce Campus, 35430 Izmir, Turkey
| | - Mustafa Germeç
- Department of Food Engineering, Faculty of Engineering, Akdeniz University, 07058 Antalya, Turkey
| | - Canan Tari
- Department of Food Engineering, Izmir Institute of Technology, Gulbahce Campus, 35430 Izmir, Turkey
| | - Irfan Turhan
- Department of Food Engineering, Faculty of Engineering, Akdeniz University, 07058 Antalya, Turkey
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Zhu Y, Liang X, Zhang H, Feng W, Liu Y, Zhang F, Linhardt RJ. A comparative secretome analysis of industrial Aspergillus oryzae and its spontaneous mutant ZJGS-LZ-21. Int J Food Microbiol 2017; 248:1-9. [PMID: 28237882 DOI: 10.1016/j.ijfoodmicro.2017.02.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 01/24/2017] [Accepted: 02/05/2017] [Indexed: 10/20/2022]
Abstract
Aspergillus oryzae koji plays a crucial role in fermented food products due to the hydrolytic activities of secreted enzymes. In the present study, we performed a comparative secretome analysis of the industrial strain of Aspergillus oryzae 3.042 and its spontaneous mutantZJGS-LZ-21. One hundred and fifty two (152) differential protein spots were excised (p<0.05), and 25 proteins were identified. Of the identified proteins, 91.3% belonged to hydrolytic enzymes acting on carbohydrates or proteins. Consistent with their enzyme activities, the expression of 14 proteins involved in the degradation of cellulose, hemicellulose, starch and proteins, increased in the ZJGS-LZ-21isolate. In particular, increased levels of acid protease (Pep) may favor the degradation of soy proteins in acidic environments and promote the cleavage of allergenic soybean proteins in fermentation, resulting in improvements of product safety and quality. The ZJGS-LZ-21 isolate showed higher protein secretion and increased hydrolytic activities than did strain 3.042, indicating its promising application in soybean paste fermentation.
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Affiliation(s)
- Yuanyuan Zhu
- Department of Biochemical Engineering, Zhejiang Gongshang University, Hangzhou 310025, China
| | - Xinle Liang
- Department of Biochemical Engineering, Zhejiang Gongshang University, Hangzhou 310025, China.
| | - Hong Zhang
- Department of Biochemical Engineering, Zhejiang Gongshang University, Hangzhou 310025, China
| | - Wei Feng
- Zhejiang Wuweihe Food Co. Ltd, Huzhou 313213, China
| | - Ye Liu
- Zhejiang Wuweihe Food Co. Ltd, Huzhou 313213, China
| | - Fuming Zhang
- Department of Chemical and Biological Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - Robert J Linhardt
- Department of Chemical and Biological Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
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16
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Park HS, Jun SC, Han KH, Hong SB, Yu JH. Diversity, Application, and Synthetic Biology of Industrially Important Aspergillus Fungi. ADVANCES IN APPLIED MICROBIOLOGY 2017; 100:161-202. [PMID: 28732553 DOI: 10.1016/bs.aambs.2017.03.001] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The filamentous fungal genus Aspergillus consists of over 340 officially recognized species. A handful of these Aspergillus fungi are predominantly used for food fermentation and large-scale production of enzymes, organic acids, and bioactive compounds. These industrially important Aspergilli primarily belong to the two major Aspergillus sections, Nigri and Flavi. Aspergillus oryzae (section Flavi) is the most commonly used mold for the fermentation of soybeans, rice, grains, and potatoes. Aspergillus niger (section Nigri) is used in the industrial production of various enzymes and organic acids, including 99% (1.4 million tons per year) of citric acid produced worldwide. Better understanding of the genomes and the signaling mechanisms of key Aspergillus species can help identify novel approaches to enhance these commercially significant strains. This review summarizes the diversity, current applications, key products, and synthetic biology of Aspergillus fungi commonly used in industry.
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Affiliation(s)
- Hee-Soo Park
- Kyungpook National University, Daegu, Republic of Korea
| | | | | | | | - Jae-Hyuk Yu
- University of Wisconsin, Madison, WI, United States
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17
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Zhu Y, Li J, Yao K, Zhao N, Zhou K, Hu X, Zou L, Han X, Liu A, Liu S. Degradation of 3-phenoxybenzoic acid by a filamentous fungus Aspergillus oryzae M-4 strain with self-protection transformation. Appl Microbiol Biotechnol 2016; 100:9773-9786. [DOI: 10.1007/s00253-016-7847-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 08/04/2016] [Accepted: 09/08/2016] [Indexed: 11/25/2022]
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18
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Wirth HP, Yang M. Different Pathophysiology of Gastritis in East and West? A Western Perspective. Inflamm Intest Dis 2016; 1:113-122. [PMID: 29922666 DOI: 10.1159/000446300] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 04/13/2016] [Indexed: 12/11/2022] Open
Abstract
Background Gastritis results from multifactorial gastric mucosal injury. Helicobacter pylori (Hp) is the main cause, and associated diseases have typical underlying patterns of gastritis. Gastric ulcer and gastric cancer (GC) develop from chronic atrophic corpus gastritis (CAG) which therefore represents the most important pattern. GC incidences in East Asia are substantially higher than elsewhere, and this should be also reflected by higher prevalences of CAG and characteristic differences in pathophysiology compared to the West. Summary The few available comparative studies of gastritis in Eastern and Western patients are summarized. The main pathogenic factors of gastritis are discussed together with their limitations to explain local differences in disease outcome. Emphasis was put to also include less well-established pathogenic host and environmental factors of possible impact. Conclusions CAG is more prevalent in East Asian areas with high GC incidences than the West. Geographic heterogeneity of associated diseases is due to differences in Hp prevalence and virulence as well as modulating host and environmental factors. The following may contribute to the higher burden of CAG in the East: ABD type of CagA with vacA s1 and babA2 alleles of Hp, host Lewis(b) expression in sej/sej nonsecretors, H. heilmannii, low parietal cell mass, high sodium and nitrate intake, preferences in vegetable and fruit consumption, cigarette smoking, air pollution, alcohol. Conversely, green tea, nonfermented soy products and rice may confer protective effects. Hp is on the decline, but also in a world cleared from this bacterium, differences in host genetics will continue to modify gastric disease outcome together with maintained customs as part of cultural diversity.
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Affiliation(s)
| | - Manqiao Yang
- GastroZentrumKreuzlingen, Kreuzlingen, Switzerland
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19
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Chang PK, Scharfenstein LL, Solorzano CD, Abbas HK, Hua SST, Jones WA, Zablotowicz RM. High sequence variations in the region containing genes encoding a cellular morphogenesis protein and the repressor of sexual development help to reveal origins of Aspergillus oryzae. Int J Food Microbiol 2015; 200:66-71. [PMID: 25689355 DOI: 10.1016/j.ijfoodmicro.2015.01.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Revised: 01/21/2015] [Accepted: 01/28/2015] [Indexed: 01/28/2023]
Abstract
Aspergillus oryzae and Aspergillus flavus are closely related fungal species. The A. flavus morphotype that produces numerous small sclerotia (S strain) and aflatoxin has a unique 1.5 kb deletion in the norB-cypA region of the aflatoxin gene cluster (i.e. the S genotype). Phylogenetic studies have indicated that an isolate of the nonaflatoxigenic A. flavus with the S genotype is the ancestor of A. oryzae. Genome sequence comparison between A. flavus NRRL3357, which produces large sclerotia (L strain), and S-strain A. flavus 70S identified a region (samA-rosA) that was highly variable in the two morphotypes. A third type of samA-rosA region was found in A. oryzae RIB40. The three samA-rosA types were later revealed to be commonly present in A. flavus L-strain populations. Of the 182 L-strain A. flavus field isolates examined, 46%, 15% and 39% had the samA-rosA type of NRRL3357, 70S and RIB40, respectively. The three types also were found in 18 S-strain A. flavus isolates with different proportions. For A. oryzae, however, the majority (80%) of the 16 strains examined had the RIB40 type and none had the NRRL3357 type. The results suggested that A. oryzae strains in the current culture collections were mostly derived from the samA-rosA/RIB40 lineage of the nonaflatoxigenic A. flavus with the S genotype.
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Affiliation(s)
- Perng-Kuang Chang
- Southern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, New Orleans, LA 70124, United States.
| | - Leslie L Scharfenstein
- Southern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, New Orleans, LA 70124, United States
| | - Cesar D Solorzano
- Biological Control of Pests Research Unit, Agricultural Research Service, U.S. Department of Agriculture, Stoneville, MS 38776, United States
| | - Hamed K Abbas
- Biological Control of Pests Research Unit, Agricultural Research Service, U.S. Department of Agriculture, Stoneville, MS 38776, United States
| | - Sui-Sheng T Hua
- Western Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, Albany, CA, 94710, United States
| | - Walker A Jones
- Biological Control of Pests Research Unit, Agricultural Research Service, U.S. Department of Agriculture, Stoneville, MS 38776, United States
| | - Robert M Zablotowicz
- Crop Production Systems Research Unit, Agricultural Research Service, U.S. Department of Agriculture, Stoneville, MS 38776, United States
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20
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Heerd D, Diercks-Horn S, Fernández-Lahore M. Efficient polygalacturonase production from agricultural and agro-industrial residues by solid-state culture of Aspergillus sojae under optimized conditions. SPRINGERPLUS 2014; 3:742. [PMID: 25674471 PMCID: PMC4320240 DOI: 10.1186/2193-1801-3-742] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 12/09/2014] [Indexed: 11/10/2022]
Abstract
Previously identified fungal pectinase producers of the species Aspergillus sojae were used for optimization of polygalacturonase production in solid-state fermentation applying Design of Experiment. The effects of media composition and several process parameters, like inoculum size, moisture level, incubation time and temperature on polygalacturonase activity were studied in screening and optimization investigations. Utilization of agricultural and agro-industrial by-products provided the establishment of a cost-efficient and sustainable process for enzyme production. Comparison of pectinase production by A. sojae ATCC 20235 and A. sojae CBS 100928 under optimized conditions yielded 6.9 times higher polygalacturonase activity by A. sojae ATCC 20235. Highest enzyme yield (909.5 ± 2.7 U/g) was obtained by A. sojae ATCC 20235 after 8 days at 30°C applying 30% sugar beet pulp as inducer substrate in combination with wheat bran as medium wetted at 160% with 0.2 M HCl. Furthermore, an overview of pectinolytic enzyme activities present in the extracts of both strains is provided. Protein profiles of both strains are given by SDS-PAGE electrophoresis, as well as zymograms for pectinolytic enzymes in comparison to commercial pectinase preparations.
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Affiliation(s)
- Doreen Heerd
- Downstream Processing Laboratory, Jacobs University Bremen gGmbH, Campus Ring 1, 28759 Bremen, Germany
| | - Sonja Diercks-Horn
- Downstream Processing Laboratory, Jacobs University Bremen gGmbH, Campus Ring 1, 28759 Bremen, Germany
| | - Marcelo Fernández-Lahore
- Downstream Processing Laboratory, Jacobs University Bremen gGmbH, Campus Ring 1, 28759 Bremen, Germany
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21
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Anticipation of future notifications to EFSA of microbial taxonomic units intentionally introduced into the food chain. EFSA J 2013. [DOI: 10.2903/j.efsa.2013.3340] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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22
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Yu L, Ding F, Ye H. Analysis of characteristic flavour compounds in Chinese rice wines and representative fungi in wheatQusamples from different regions. JOURNAL OF THE INSTITUTE OF BREWING 2012. [DOI: 10.1002/jib.13] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Lijuan Yu
- School of Life Science; Nantong University; 9 Seyuan Rd; Nantong; 226019; Jiangsu; People's Republic of China
| | - Fei Ding
- School of Life Science; Nantong University; 9 Seyuan Rd; Nantong; 226019; Jiangsu; People's Republic of China
| | - Hui Ye
- School of Life Science; Nantong University; 9 Seyuan Rd; Nantong; 226019; Jiangsu; People's Republic of China
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23
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Bellanger AP, Roussel A, Millon L, Delaforge M, Reboux G. Jewelry boxes contaminated by Aspergillus oryzae: an occupational health risk? JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2012; 9:460-466. [PMID: 22702230 DOI: 10.1080/15459624.2012.691332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
In 2009, 100,000 jewelry boxes, manufactured in China, were delivered to a jewelry manufacturer in Besançon, France. All the boxes were contaminated by mold. Because the workers refused to handle these jewelry boxes, the company contacted our laboratory to determine how to deal with the problem. Three choices were available: (1) decontaminate the boxes, (2) return the boxes to the Chinese manufacturer, or (3) destroy the entire shipment. Based on microscopic identification, the culture analysis was positive for A. oryzae. This could not be confirmed by molecular techniques because of the genetic proximity of A. oryzae and A. flavus. Because A. flavus can produce aflatoxins, we tested for them using mass spectrometry. Aflatoxins B1, B2, G1, G2, and M1 were not detected; however, given the specifics of this situation, we could not discard the possibility of the presence of other aflatoxins, such as P1, B3, GM2, and ethoxyaflatoxin B2. We concluded that the contamination by A. oryzae was probably due to food products. However, because of the possible presence of aflatoxins, occupational health risks could not be entirely ruled out. The decision was therefore taken to destroy all the jewelry boxes by incineration. To avoid a similar situation we propose: (1) to maintain conditions limiting mold contamination during production (not eating on the work site, efficient ventilation systems); (2) to desiccate the products before sending them; and (3) to closely control the levels of dampness during storage and transport.
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Varga J, Frisvad J, Samson R. Two new aflatoxin producing species, and an overview of Aspergillus section Flavi. Stud Mycol 2011; 69:57-80. [PMID: 21892243 PMCID: PMC3161756 DOI: 10.3114/sim.2011.69.05] [Citation(s) in RCA: 208] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Aspergillus subgenus Circumdati section Flavi includes species with usually biseriate conidial heads, in shades of yellow-green to brown, and dark sclerotia. Several species assigned to this section are either important mycotoxin producers including aflatoxins, cyclopiazonic acid, ochratoxins and kojic acid, or are used in oriental food fermentation processes and as hosts for heterologous gene expression. A polyphasic approach was applied using morphological characters, extrolite data and partial calmodulin, β-tubulin and ITS sequences to examine the evolutionary relationships within this section. The data indicate that Aspergillus section Flavi involves 22 species, which can be grouped into seven clades. Two new species, A. pseudocaelatus sp. nov. and A. pseudonomius sp. nov. have been discovered, and can be distinguished from other species in this section based on sequence data and extrolite profiles. Aspergillus pseudocaelatus is represented by a single isolate collected from Arachis burkartii leaf in Argentina, is closely related to the non-aflatoxin producing A. caelatus, and produces aflatoxins B & G, cyclopiazonic acid and kojic acid, while A. pseudonomius was isolated from insects and soil in the USA. This species is related to A. nomius, and produces aflatoxin B(1) (but not G-type aflatoxins), chrysogine and kojic acid. In order to prove the aflatoxin producing abilities of the isolates, phylogenetic analysis of three genes taking part in aflatoxin biosynthesis, including the transcriptional regulator aflR, norsolonic acid reductase and O-methyltransferase were also carried out. A detailed overview of the species accepted in Aspergillus section Flavi is presented.
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Affiliation(s)
- J. Varga
- CBS Fungal Biodiversity Centre, Uppsalalaan 8, NL-3584 CT Utrecht, the Netherlands
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, H-6726 Szeged, Közép fasor 52, Hungary
| | - J.C. Frisvad
- Center for Microbial Biotechnology, Department of Systems Biology, Building 221, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - R.A. Samson
- CBS Fungal Biodiversity Centre, Uppsalalaan 8, NL-3584 CT Utrecht, the Netherlands
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25
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Sheih IC, Fang TJ, Wu TK, Chang CH, Chen RY. Purification and properties of a novel phenolic antioxidant from Radix astragali fermented by Aspergillus oryzae M29. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2011; 59:6520-6525. [PMID: 21557623 DOI: 10.1021/jf2011547] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The Chinese herb Radix astragalus (RA) has been widely used as a dietary supplement in Asia, and there are numerous reports on its bioactivities. However, there are no reports to date regarding the use of Aspergillus spp. in the culture medium of the RA plant for the production of phenolic antioxidants. In this study, utilizing the fungus Aspergillus to ferment the native RA has successfully resulted in a significant increase in the phenolic contents of RA, and the fermented RA also revealed much better antioxidant activity toward 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radicals, hydroxyl radical, superoxide radical and peroxyl radical than those of unfermented RA. Among these phenolics, a potent novel antioxidant was isolated and identified as 3,4-di(4'-hydroxyphenyl) isobutyric acid with a molecular weight of 272, by ESI-MS (electrospray ionization mass), ¹H NMR (nuclear magnetic resonance), ¹³C NMR, DEPT (distortionless enhancement by polarization transfer)-NMR, HMQC (heteronuclear multiple quantum coherence), and HMBC (heteronuclear multiple bond correlation) spectra. These data demonstrated that the solid-state bioprocessing strategy could be an innovative approach to enhance the antioxidant activity of RA.
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Affiliation(s)
- I-Chuan Sheih
- Department of Food Science and Biotechnology, National Chung Hsing University , 250 Kuokuang Road, Taichung 40227, Taiwan, Republic of China
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Kato N, Tokuoka M, Shinohara Y, Kawatani M, Uramoto M, Seshime Y, Fujii I, Kitamoto K, Takahashi T, Takahashi S, Koyama Y, Osada H. Genetic Safeguard against Mycotoxin Cyclopiazonic Acid Production in Aspergillus oryzae. Chembiochem 2011; 12:1376-82. [DOI: 10.1002/cbic.201000672] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2010] [Indexed: 11/11/2022]
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Liu WC, Li CQ, Zhu P, Yang JL, Cheng KD. Phylogenetic diversity of culturable fungi associated with two marine sponges: Haliclona simulans and Gelliodes carnosa, collected from the Hainan Island coastal waters of the South China Sea. FUNGAL DIVERS 2010. [DOI: 10.1007/s13225-010-0022-8] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Abstract
Aflatoxins are decaketide-derived secondary metabolites which are produced by a complex biosynthetic pathway. Aflatoxins are among the economically most important mycotoxins. Aflatoxin B1 exhibits hepatocarcinogenic and hepatotoxic properties, and is frequently referred to as the most potent naturally occurring carcinogen. Acute aflatoxicosis epidemics occur in several parts of Asia and Africa leading to the death of several hundred people. Aflatoxin production has incorrectly been claimed for a long list of Aspergillus species and also for species assigned to other fungal genera. Recent data indicate that aflatoxins are produced by 13 species assigned to three sections of the genus Aspergillus: section Flavi (A. flavus, A. pseudotamarii, A. parasiticus, A. nomius, A. bombycis, A. parvisclerotigenus, A. minisclerotigenes, A. arachidicola), section Nidulantes (Emericella astellata, E. venezuelensis, E. olivicola) and section Ochraceorosei (A. ochraceoroseus, A. rambellii). Several species claimed to produce aflatoxins have been synonymised with other aflatoxin producers, including A. toxicarius (=A. parasiticus), A. flavus var. columnaris (=A. flavus) or A. zhaoqingensis (=A. nomius). Compounds with related structures include sterigmatocystin, an intermediate of aflatoxin biosynthesis produced by several Aspergilli and species assigned to other genera, and dothistromin produced by a range of non-Aspergillus species. In this review, we wish to give an overview of aflatoxin production including the list of species incorrectly identified as aflatoxin producers, and provide short descriptions of the 'true' aflatoxin producing species.
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Affiliation(s)
- J. Varga
- CBS Fungal Biodiversity Centre, P.O. Box 85167, 3508 AD Utrecht, the Netherlands
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Közép fasor 52, 6726 Szeged, Hungary
| | - J. Frisvad
- Department of Systems Biology, Center for Microbial Biotechnology, Building 221, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - R. Samson
- CBS Fungal Biodiversity Centre, P.O. Box 85167, 3508 AD Utrecht, the Netherlands
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Jørgensen TR, Goosen T, Hondel CAMJJVD, Ram AFJ, Iversen JJL. Transcriptomic comparison of Aspergillus niger growing on two different sugars reveals coordinated regulation of the secretory pathway. BMC Genomics 2009; 10:44. [PMID: 19166577 PMCID: PMC2639373 DOI: 10.1186/1471-2164-10-44] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2008] [Accepted: 01/23/2009] [Indexed: 11/24/2022] Open
Abstract
Background The filamentous fungus, Aspergillus niger, responds to nutrient availability by modulating secretion of various substrate degrading hydrolases. This ability has made it an important organism in industrial production of secreted glycoproteins. The recent publication of the A. niger genome sequence and availability of microarrays allow high resolution studies of transcriptional regulation of basal cellular processes, like those of glycoprotein synthesis and secretion. It is known that the activities of certain secretory pathway enzymes involved N-glycosylation are elevated in response to carbon source induced secretion of the glycoprotein glucoamylase. We have investigated whether carbon source dependent enhancement of protein secretion can lead to upregulation of secretory pathway elements extending beyond those involved in N-glycosylation. Results This study compares the physiology and transcriptome of A. niger growing at the same specific growth rate (0.16 h-1) on xylose or maltose in carbon-limited chemostat cultures. Transcription profiles were obtained using Affymetrix GeneChip analysis of six replicate cultures for each of the two growth-limiting carbon sources. The production rate of extracellular proteins per gram dry mycelium was about three times higher on maltose compared to xylose. The defined culture conditions resulted in high reproducibility, discriminating even low-fold differences in transcription, which is characteristic of genes encoding basal cellular functions. This included elements in the secretory pathway and central metabolic pathways. Increased protein secretion on maltose was accompanied by induced transcription of > 90 genes related to protein secretion. The upregulated genes encode key elements in protein translocation to the endoplasmic reticulum (ER), folding, N-glycosylation, quality control, and vesicle packaging and transport between ER and Golgi. The induction effect of maltose resembles the unfolded protein response (UPR), which results from ER-stress and has previously been defined by treatment with chemicals interfering with folding of glycoproteins or by expression of heterologous proteins. Conclusion We show that upregulation of secretory pathway genes also occurs in conditions inducing secretion of endogenous glycoproteins – representing a more normal physiological state. Transcriptional regulation of protein synthesis and secretory pathway genes may thus reflect a general mechanism for modulation of secretion capacity in response to the conditional need for extracellular enzymes.
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Affiliation(s)
- Thomas R Jørgensen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense M, Denmark.
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