Aspergillus flavus aswA , a gene homolog of Aspergillus nidulans oefC , regulates sclerotial development and biosynthesis of sclerotium-associated secondary metabolites

2017 ◽  
Vol 104 ◽  
pp. 29-37 ◽  
Author(s):  
Perng-Kuang Chang ◽  
Leslie L. Scharfenstein ◽  
Robert W. Li ◽  
Natalia Arroyo-Manzanares ◽  
Sarah De Saeger ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Aspergillus Nidulans ◽  
Aspergillus Flavus ◽  
Sclerotial Development

scholarly journals Vibrio gazogenes inhibits aflatoxin production through downregulation of aflatoxin biosynthetic genes in Aspergillus flavus

2022 ◽  
Author(s):  
Shyam L. Kandel ◽  
Rubaiya Jesmin ◽  
Brian M. Mack ◽  
Rajtilak Majumdar ◽  
Matthew K. Gilbert ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Secondary Metabolite ◽  
Aspergillus Flavus ◽  
Fungal Biomass ◽  
Expression Profiles ◽  
Health Hazard ◽  
Gene Clusters ◽  
Aflatoxin Contamination ◽  
Aflatoxin Biosynthesis ◽  
Control Samples

Aspergillus flavus is an opportunistic pathogen of oilseed crops such as maize, peanut, cottonseed, and tree nuts and produces carcinogenic secondary metabolites known as aflatoxins during seed colonization. Aflatoxin contamination not only reduces the value of the produce but also is a health hazard to humans and animals. Previously, we observed inhibition of A. flavus aflatoxin biosynthesis upon exposure to the marine bacterium, Vibrio gazogenes (Vg). In this study, we used RNA sequencing to examine the transcriptional profiles of A. flavus treated with both live and heat-inactivated dead Vg and control samples. Fungal biomass, total accumulated aflatoxins, and expression profiles of genes constituting secondary metabolite biosynthetic gene clusters were determined at 24, 30, and 40 h after treatment. Statistically significant reductions in total aflatoxins were detected in Vg-treated samples as compared to control samples at 40 h. But no statistical difference in fungal biomass was observed upon these treatments. The Vg treatments were most effective on aflatoxin biosynthesis as was reflected in significant downregulation of majority of the genes in the aflatoxin gene cluster including the aflatoxin pathway regulator gene, aflR. Along with aflatoxin genes, we also observed significant downregulation in some other secondary metabolite gene clusters including cyclopiazonic acid and aflavarin, suggesting that the treatment may inhibit other secondary metabolites as well. Finally, a weighted gene correlation network analysis identified an upregulation of ten genes that were most strongly associated with Vg-dependent aflatoxin inhibition and provide a novel start-point in understanding the mechanisms that result in this phenomenon.

scholarly journals عزل وتعريف واختبار كفاءة بعض الفطريات في تحلل الهيدروكربون من التربة الملوثة بالنفط

2020 ◽  
Vol 3 (1) ◽  
pp. 78-90
Author(s):  
سعاد محمد خليفة أبوالغيث ◽  
أحلام القمودي محمد زعيط
Keyword(s):  
Aspergillus Niger ◽  
Aspergillus Fumigatus ◽  
Aspergillus Nidulans ◽  
Aspergillus Flavus ◽  
Malt Extract Agar ◽  
Malt Extract ◽  
Extract Agar

استهدفت هذه الدراسة عزل بعض أنواع الفطريات من التربة الملوثة بالهيدروكربون بمصفاة الزاوية لتكرير النفط، حيث تم عزل وتعريف بعض الفطريات مثل Rhizopus, Aspergillus fumigatus, Aspergillus niger, Aspergillus flavus, Aspergillus nidulans وأوضحت نتائج هذه الدراسة أن تواجد وتنوع فطر Aspergillus قد تفوق معنويا مقارنة بتواجد وتنوع فطرRhizopus. كما تم في هذه الدراسة اختبار قدرة وكفاءة الفطريات المعزولة على النمو واستغلال المركبات الهيدروكربونية المتمثلة في زيت الحمادة وزيت الشرارة بتركيز 1% و3%، حيث أوضحت النتائج بأن جنس Rhizopus سجل أعلى معدل للنمو على الوسط الغذائي Malt Extract Agar، وسجل كلا من فطر A. fumigatus وفطر A. flavus معدّل النمو القطري أعلى معنويا من النمو القطري لفطرA. niger  وفطر A. nidulans. هذه المعدّلات العالية تدل على إمكانية استخدام الفطريات المعزولة في المعالجة البيولوجية للتربة الملوّثة بالنفط.

scholarly journals Comparative Study of the Secondary Metabolites of Sponge-derived Aspergillus flavus

2017 ◽  
Vol 1 (2) ◽  
pp. 45-51
Author(s):  
Kamilia Tawfik ◽  
Mostafa Mesbah ◽  
Sherief Khalifa ◽  
Eric Schmidt ◽  
Diaa Youssef
Keyword(s):  
Secondary Metabolites ◽  
Comparative Study ◽  
Aspergillus Flavus

scholarly journals Efficacy of Caspofungin against Aspergillus flavus, Aspergillus terreus, and Aspergillus nidulans

2006 ◽  
Vol 50 (12) ◽  
pp. 4202-4205 ◽  
Author(s):  
J. C. Bowman ◽  
G. K. Abruzzo ◽  
A. M. Flattery ◽  
C. J. Gill ◽  
E. J. Hickey ◽  
...  
Keyword(s):  
Aspergillus Nidulans ◽  
Amphotericin B ◽  
Filamentous Fungi ◽  
Aspergillus Flavus ◽  
Aspergillus Terreus ◽  
Potent Inhibitor ◽  
Murine Models ◽  
Glucan Synthase ◽  
Fungal Burden

ABSTRACT The echinocandin caspofungin is a potent inhibitor of the activity of 1,3-β-d-glucan synthase from Aspergillus flavus, Aspergillus terreus, and Aspergillus nidulans. In murine models of disseminated infection, caspofungin prolonged survival and reduced the kidney fungal burden. Caspofungin was at least as effective as amphotericin B against these filamentous fungi in vivo.

scholarly journals Aspergillic Acids Produced by Mixed Cultures of Aspergillus flavus and Aspergillus nidulans

Microbiology ◽  
1984 ◽  
Vol 130 (2) ◽  
pp. 319-323 ◽  
Author(s):  
M. J. Perry ◽  
J. F. Makins ◽  
M. W. Adlard ◽  
G. Holt
Keyword(s):  
Aspergillus Nidulans ◽  
Aspergillus Flavus ◽  
Mixed Cultures

scholarly journals Distinct Roles for VeA and LaeA in Development and Pathogenesis of Aspergillus flavus

2009 ◽  
Vol 8 (7) ◽  
pp. 1051-1060 ◽  
Author(s):  
Saori Amaike ◽  
Nancy P. Keller
Keyword(s):  
Aspergillus Flavus ◽  
Copy Number ◽  
Intermediate Phenotype ◽  
Agricultural Crops ◽  
Wild Type ◽  
Nuclear Complex ◽  
Fungal Biology ◽  
Seed Colonization ◽  
Regulatory Functions ◽  
Sclerotial Development

ABSTRACT Aspergillus flavus, a mycotoxigenic filamentous fungus, colonizes several important agricultural crops, such as maize and peanuts. Two proteins, VeA and LaeA, known to form a nuclear complex in Aspergillus nidulans have been found to positively regulate developmental processes in several Aspergillus species. Here, an examination of near-isogenic A. flavus mutants differing in copy number of veA and laeA alleles (0, 1, or at least 2 each) revealed critical roles for VeA and LaeA in A. flavus development and seed colonization. In contrast to the wild type, both null mutants were unable to metabolize host cell lipid reserves and were inhibited by oleic acid in growth assays. The copy number of LaeA but not VeA appeared critical for a density-dependent sclerotial-to-conidial shift, since the multicopy laeA (MClaeA) strain produced relatively constant sclerotial numbers with increasing population size rather than showing the decrease in sclerotia seen in both the wild-type and MCveA strains. The MCveA-laeA strain yielded an intermediate phenotype. This study revealed unique roles of VeA and LaeA in seed pathogenesis and fungal biology, distinct from their cooperative regulatory functions in aflatoxin and sclerotial development.

scholarly journals Lack of Host Specialization inAspergillus flavus

2000 ◽  
Vol 66 (1) ◽  
pp. 320-324 ◽  
Author(s):  
Raymond J. St. Leger ◽  
Steven E. Screen ◽  
Bijan Shams-Pirzadeh
Keyword(s):  
Aspergillus Fumigatus ◽  
Aspergillus Nidulans ◽  
Aspergillus Flavus ◽  
Galleria Mellonella ◽  
Host Specialization ◽  
Plant Tissues ◽  
Animal Hosts ◽  
Insect Hemocytes ◽  
Corn Kernels ◽  
Bean Leaves

ABSTRACT Aspergillus spp. cause disease in a broad range of organisms, but it is unknown if strains are specialized for particular hosts. We evaluated isolates of Aspergillus flavus,Aspergillus fumigatus, and Aspergillus nidulansfor their ability to infect bean leaves, corn kernels, and insects (Galleria mellonella). Strains of A. flavus did not affect nonwounded bean leaves, corn kernels, or insects at 22°C, but they killed insects following hemocoelic challenge and caused symptoms ranging from moderate to severe in corn kernels and bean leaves injured during inoculation. The pectinase P2c, implicated in aggressive colonization of cotton bolls, is produced by most A. flavus isolates, but its absence did not prevent colonization of bean leaves. Proteases have been implicated in colonization of animal hosts. All A. flavus strains produced very similar patterns of protease isozymes when cultured on horse lung polymers. Quantitative differences in protease levels did not correlate with the ability to colonize insects. In contrast to A. flavus, strains ofA. nidulans and A. fumigatus could not invade living insect or plant tissues or resist digestion by insect hemocytes. Our results indicate that A. flavus has parasitic attributes that are lacking in A. fumigatus and A. nidulans but that individual strains of A. flavus are not specialized to particular hosts.

scholarly journals A Cellular Fusion Cascade Regulated by LaeA Is Required for Sclerotial Development in Aspergillus flavus

2017 ◽  
Vol 8 ◽  
Author(s):  
Xixi Zhao ◽  
Joseph E. Spraker ◽  
Jin Woo Bok ◽  
Thomas Velk ◽  
Zhu-Mei He ◽  
...  
Keyword(s):  
Aspergillus Flavus ◽  
Sclerotial Development ◽  
Cellular Fusion

scholarly journals Secondary Metabolites and Bioactivity of Hyophila involuta (Hook) Jaeg.

2015 ◽  
Vol 7 (4) ◽  
pp. 456-459
Author(s):  
Amos M. MAKINDE ◽  
Eunice A. FAJUYIGBE ◽  
Musibau O. ISA
Keyword(s):  
Staphylococcus Aureus ◽  
Secondary Metabolites ◽  
Aspergillus Flavus ◽  
Cardiac Glycosides ◽  
Therapeutic Potential ◽  
Ethanolic Extract ◽  
Acetone Extract ◽  
Significant Activity ◽  
Phytochemical Screening ◽  
Ethanolic Extracts

The phytochemical screening of Hyophila involuta collected from the Biological Garden of the Obafemi Awolowo University, Ile-Ife, Nigeria, was carried out to investigate the presence or absence of some secondary metabolites and its antibiotic potentials, using different extracts (with acetone and ethanol) on selected organisms. The extracts obtained were screened for the presence of secondary metabolites like alkaloids, anthraquinones, cardiac glycosides, flavonoids, phlobatanins, saponins, steroids, tannins, triterpenes and xanthoproteins. Antimicrobial activity of the extracts was carried out on Escherichia coli, Staphylococcus aureus, Aspergillus flavus and Candida albicans. Only acetone extract tested positive for the presence of flavonoids, while alkaloids and cardiac glycosides were detected present in both the acetone and ethanolic extracts. Flavonoids were detected present only in the acetone extract. Saponins were detected present only in the ethanolic extract. The extracts (acetone and ethanolic) showed significant activity on Staphylococcus aureus and Aspergillus flavus. The results obtained from this study indicated that H. involuta has medicinally important compounds, having therapeutic potential from which effective antimicrobial medicine can be sourced.

Sign in / Sign up

Export Citation Format

Share Document