Influence of Neighboring Clonal-Colonies on Aflatoxin Production by Aspergillus flavus

Aspergillus flavus is an ascomycete fungus that infects and contaminates corn, peanuts, cottonseed, and treenuts with acutely toxic and carcinogenic aflatoxins. The ecological function of aflatoxin production is not well understood; though not phytotoxic, aflatoxin may be involved in resisting oxidative stress responses from infection or drought stress in plants. Observation of aflatoxin stimulation in 48-well plates in response to increasing inoculated wells sparked an investigation to determine if A. flavus volatiles influence aflatoxin production in neighboring colonies. Experiments controlling several culture conditions demonstrated a stimulation of aflatoxin production with increased well occupancy independent of pH buffer, moisture, or isolate. However, even with all wells inoculated, aflatoxin production was less in interior wells. Only one isolate stimulated aflatoxin production in a large Petri-dish format containing eight small Petri dishes with shared headspace. Other isolates consistently inhibited aflatoxin production when all eight Petri dishes were inoculated with A. flavus. No contact between cultures and only shared headspace implied the fungus produced inhibitory and stimulatory gases. Adding activated charcoal between wells and dishes prevented inhibition but not stimulation indicating stimulatory and inhibitory gases are different and/or gas is inhibitory at high concentration and stimulatory at lower concentrations. Characterizing stimulatory and inhibito...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research

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In this study, three major SGs, i.e., glucosides of β-sitosterol, stigmasterol, and campesterol, were synthesized and used as standards for measurement of their contents in rice bran (RB)-based fermented food (FBRA) utilizing Aspergillus oryzae and raw material (RM). The compounds were quantified using liquid chromatography/electrospray ionization-tandem mass spectrometry. It was found that β-sitosteryl glucoside was most abundant among the analyzed glucosides in both samples, and the contents of each SG in FBRA decreased about 35% from those of RM. In contrast to SGs, the contents of ASGs in FBRA increased 1.5-f...
Source: Steroids - Category: Drugs & Pharmacology Source Type: research
Publication date: Available online 18 February 2020Source: Food ControlAuthor(s): Luísa Freire, Patrícia A.C. Braga, Marianna M. Furtado, Jeany Delafiori, Flávia L. Dias-Audibert, Giuliano E. Pereira, Felix G. Reyes, Rodrigo R. Catharino, Anderson S. Sant’AnaAbstractThe presence of ochratoxin A (OTA) in wine is mainly due to the contamination of grapes by Aspergillus carbonarius and A. niger, still in the vineyard or at stages prior to winemaking. Throughout winemaking process, although there is a reduction in OTA levels, modified mycotoxins may also be formed. In fact, modified mycotoxins are co...
Source: Food Control - Category: Food Science Source Type: research
n Bills Aspergillus pachycristatus is an industrially important fungus for the production of the antifungal echinocandin B and is closely related to model organism A. nidulans. Its secondary metabolism is largely unknown except for the production of echinocandin B and sterigmatocystin. We constructed mutants for three genes that regulate secondary metabolism in A. pachycristatus NRRL 11440, and evaluated the secondary metabolites produced by wild type and mutants strains. The secondary metabolism was explored by metabolic networking of UPLC-HRMS/MS data. The genes and metabolites of A. pachycristatus were compared t...
Source: Molecules - Category: Chemistry Authors: Tags: Article Source Type: research
This study provides a solid evidence to discover the biological functions of histone methyltransferase in pathogenic fungi.
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
Aspergilloma, also known as mycetoma or fungus ball, is the most common manifestation of pulmonary involvement by Aspergillus species. The fungal ball typically forms within preexisting cavities of the lungs. Diagnosis requires both radiographic evidence along with serologic or microbiologic evidence of Aspergillus species involvement. While clinical features such as hemoptysis, chest pain, shortness of breath, cough, and fever are helpful in diagnosis, they are non-specific symptoms. Surgery is currently the mainstay of treatment for aspergilloma but is associated with considerable mortality and morbidity.
Source: Respiratory Medicine - Category: Respiratory Medicine Authors: Tags: Review article Source Type: research
Publication date: Available online 15 February 2020Source: Biocatalysis and Agricultural BiotechnologyAuthor(s): Harshitha Madhusoodan Jathanna, Chandrayan Vaman Rao, Louella Concepta GoveasAbstractBiofuels and their production is the need of the hour considering the current fuel crisis. In this regard, ways of mitigating biodiesel production costs is being actively researched upon. With the same intention, in the present work, an investigation was carried out to test the capability of utilizing the hydrolysates of de-oiled Pongamia seed cake, a byproduct of biodiesel, for microbial lipid production using Aspergillus ochra...
Source: Biocatalysis and Agricultural Biotechnology - Category: Biotechnology Source Type: research
Authors: Meyer D, Smit DP Abstract Both infective and neoplastic eyelid and orbital conditions in human immunodeficiency virus (HIV) infected patients are often the result of opportunistic or co-infections (OI). In most cases, these clinical findings in younger patients alert the physician to suspected underlying HIV infection. When the eyelids and periorbital skin are primarily involved in OI with varicella-zoster virus it is called Herpes Zoster Ophthalmicus. Co-infection with a Pox virus manifests as molluscum contagiosum eruptions. Orbital cellulitis is secondary to various organisms (Mycobacterium tuberculosis...
Source: Ocular Immunology and Inflammation - Category: Allergy & Immunology Tags: Ocul Immunol Inflamm Source Type: research
Authors: Díaz Alcázar MDM, Ruiz Escolano E, Casado Caballero FJ, Cervilla Sáez de Tejada E Abstract A 72-year-old female presented with abdominal pain and constipation and intestinal dilation was found. Abdominal computed tomography showed two areas of thickening and stenosis in the proximal jejunum and preterminal ileum, with an unknown etiology. Exploratory laparotomy was proposed but the patient suffered a sudden and progressive decrease in consciousness. Cranial computed tomography showed an ischemic area and a midline shift. Brain biopsies suggested infection by Aspergillus Fumigatus. Desp...
Source: Revista Espanola de Enfermedades Digestivas - Category: Gastroenterology Tags: Rev Esp Enferm Dig Source Type: research
Publication date: March 2020Source: Biocatalysis and Agricultural Biotechnology, Volume 24Author(s): Ashraf S.A. El-Sayed, Ahmed H. Moustafa, Hussein A. Hussein, Aly A. El-Sheikh, Samah N. El-Shafey, Nahla A.M. Fathy, Gamal A. EnanAbstractSpodoptera littoralis has been recognized as the major destructive cause of various economic crops in Egypt. Chemical insecticides have been frequently used, however, the development of insecticidal resistance is the current challenge, thus searching for novel ecofriendly biocontrol agents is the prospective challenge. Fungal endophytes of plants have been recognized as a repertoire for b...
Source: Biocatalysis and Agricultural Biotechnology - Category: Biotechnology Source Type: research
Publication date: Available online 15 February 2020Source: Journal of Advanced ResearchAuthor(s): Mahwish Siddiqui, Atia-tul-Wahab, Almas Jabeen, Yan Wang, Wei Wang, Atta-ur-Rahman, M. Iqbal ChoudharyAbstractSeven new derivatives, 6α-hydroxy-1-methyl-3-oxo-5α-androst-1-en-17-yl acetate (2), 6α,17β-dihydroxy-1-methyl-3-oxo-5α-androst-1-en (3), 7β-hydroxy-1-methyl-3-oxo-5α-androst-1-en-17-yl acetate (4), 15β,20-dihydroxy-1-methyl-3-oxo-5α-androst-1-en-17-yl acetate (5), 15β-hydroxy-1-methyl-3-oxo-5α-androst-1-en-17-yl acetate (6), 12β,17β-dihydroxy-1-met...
Source: Journal of Advanced Research - Category: Research Source Type: research
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