scholarly journals Analysis of impact of anaerobic condition on the aflatoxin production in Aspergillus parasiticus Speare

2019 ◽  
Vol 39 (1) ◽  
Author(s):  
Maneesh Department of Biotechnology, Mag Kumar ◽  
Harish Kumar ◽  
Roshan Kamal Topno ◽  
Jainendra Kumar
Keyword(s):  
High Performance ◽  
Aspergillus Parasiticus ◽  
Quantitative Estimation ◽  
Fungal Growth ◽  
Aflatoxin Production ◽  
Agricultural Products ◽  
Aflatoxin Biosynthesis ◽  
Anaerobic Conditions ◽  
Toxic Contamination ◽  
Aerobic And Anaerobic

Aflatoxins are the natural carcinogens that are the best characterized as fungal secondary metabolites. The producers that are responsible for aflatoxin biosynthesis are strongly associated in toxic contamination of essential agricultural products. Aspergillus parasiticus is an exclusive fungus that participates in causing hepatic problems in humans and cattle. These mycotoxins are greatly influenced by abiotic stresses. The fungal growth, proliferation and its toxigenicity are highly influenced by these stresses. Present study aimed to restrict the mycelial growth and to prevent aflatoxin preparation in A. parasiticus under the anoxic stress. The monosporic strains of A. parasiticus were grown in two different Erlenmeyer conical flasks containing Czapek Dox Broth and Czapek Dox Agar under both aerobic and anaerobic conditions. The anoxic condition was maintained using Anaero Bag System. Aflatoxin was isolated after 10 days, and quantitative estimation was done by using High Performance Liquid Chromatography (HPLC). The experimental outcome showed that there was a drastic decrease in both the morphological growth and the aflatoxin biosynthesis of A. parasiticus in anoxic state.

scholarly journals Cyclo(l-Leucyl-l-Prolyl) Produced by Achromobacter xylosoxidans Inhibits Aflatoxin Production by Aspergillus parasiticus

2004 ◽  
Vol 70 (12) ◽  
pp. 7466-7473 ◽  
Author(s):  
Pei-Sheng Yan ◽  
Yuan Song ◽  
Emi Sakuno ◽  
Hiromitsu Nakajima ◽  
Hiroyuki Nakagawa ◽  
...  
Keyword(s):  
High Performance ◽  
Aspergillus Parasiticus ◽  
Fungal Growth ◽  
Culture Method ◽  
Aflatoxin Production ◽  
Alkaline Treatment ◽  
Achromobacter Xylosoxidans ◽  
Toxic Substances ◽  
Inhibitory Substance ◽  
Reverse Transcription Pcr

ABSTRACT Aflatoxins are potent carcinogenic and toxic substances that are produced primarily by Aspergillus flavus and Aspergillus parasiticus. We found that a bacterium remarkably inhibited production of norsolorinic acid, a precursor of aflatoxin, by A. parasiticus. This bacterium was identified as Achromobacter xylosoxidans based on its 16S ribosomal DNA sequence and was designated A. xylosoxidans NFRI-A1. A. xylosoxidans strains commonly showed similar inhibition. The inhibitory substance(s) was excreted into the medium and was stable after heat, acid, or alkaline treatment. Although the bacterium appeared to produce several inhibitory substances, we finally succeeded in purifying a major inhibitory substance from the culture medium using Diaion HP20 column chromatography, thin-layer chromatography, and high-performance liquid chromatography. The purified inhibitory substance was identified as cyclo(l-leucyl-l-prolyl) based on physicochemical methods. The 50% inhibitory concentration for aflatoxin production by A. parasiticus SYS-4 (= NRRL2999) was 0.20 mg ml−1, as determined by the tip culture method. High concentrations (more than 6.0 mg ml−1) of cyclo(l-leucyl-l-prolyl) further inhibited fungal growth. Similar inhibitory activities were observed with cyclo(d-leucyl-d-prolyl) and cyclo(l-valyl-l-prolyl), whereas cyclo(d-prolyl-l-leucyl) and cyclo(l-prolyl-d-leucyl) showed weaker activities. Reverse transcription-PCR analyses showed that cyclo(l-leucyl-l-prolyl) repressed transcription of the aflatoxin-related genes aflR, hexB, pksL1, and dmtA. This is the first report of a cyclodipeptide that affects aflatoxin production.

scholarly journals Use of Selected Essential Oils to Control Aflatoxin Contaminated Stored Cashew and Detection of Aflatoxin Biosynthesis Gene

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Abeer R. M. Abd El-Aziz ◽  
Mohamed A. Mahmoud ◽  
Monira R. Al-Othman ◽  
Munirah F. Al-Gahtani
Keyword(s):  
Essential Oils ◽  
High Performance ◽  
Biosynthetic Pathway ◽  
Culture Media ◽  
Uv Light ◽  
Fungal Growth ◽  
Aflatoxin Production ◽  
Significant Inhibition ◽  
Aflatoxin Biosynthesis ◽  
Biosynthesis Gene

Aspergillusspp. associated with cashew from the regions of Riyadh, Dammam, and Abha were isolated and three different culture media were used to qualitatively measure aflatoxin production byAspergillusvia UV light (365 nm), which was expressed as positive or negative. The obtained data showed that six isolates ofA. flavusand four isolates ofA. parasiticuswere positive for aflatoxin production, while all isolates ofA. nigerwere negative. Five commercially essential oils (thyme, garlic, cinnamon, mint, and rosemary) were tested to determine their influence on growth and aflatoxin production inA. flavusandA. parasiticusby performing high-performance liquid chromatography (HPLC). The results showed that the tested essential oils caused highly significant inhibition of fungal growth and aflatoxin production inA. flavusandA. parasiticus. The extent of the inhibition of fungal growth and aflatoxin production was dependent on the type and concentration of essential oils applied. The results indicate that cinnamon and thyme oils show strong antimicrobial potential. PCR was used with four sets of primer pairs fornor-1, omt-1, ver-1, andaflRgenes, enclosed in the aflatoxin biosynthetic pathway. The interpretation of the results revealed that PCR is a rapid and sensitive method.

Control of Aspergillus flavus and aflatoxin production with spices in culture medium and rice

2013 ◽  
Vol 6 (1) ◽  
pp. 43-50 ◽  
Author(s):  
V. Aiko ◽  
A. Mehta
Keyword(s):  
Aspergillus Flavus ◽  
High Performance ◽  
Fungal Growth ◽  
Aflatoxin Production ◽  
Culture Broth ◽  
Minimum Inhibitory Concentrations ◽  
Food Grains ◽  
Star Anise ◽  
Aflatoxin B ◽  
Layer Chromatography

Cinnamon, cardamom, star anise and clove were studied for their effect on growth of Aspergillus flavus and aflatoxin B1 (AFB1) synthesis. The experiments were carried out in yeast extract sucrose culture broth as well as in rice supplemented with spices. AFB1 produced was analysed qualitatively and quantitatively using thin layer chromatography and high performance liquid chromatography, respectively. At a concentration of 10 mg/ml, cardamom and star anise did not exhibit any antifungal or anti-aflatoxigenic activity in culture broth, whereas cinnamon and clove inhibited A. flavus growth completely. The minimum inhibitory concentrations of cinnamon and clove were 4 and 2 mg/ml, respectively. Concentrations of cinnamon and clove below their minimum inhibitory concentrations showed enhanced fungal growth, while AFB1 synthesis was reduced. Clove inhibited the synthesis of AFB1 significantly up to 99% at concentrations ≥1.0 mg/ml. The spices also inhibited AFB1 synthesis in rice at 5 mg/g, although fungal growth was not inhibited. Clove and cinnamon inhibited AFB1 synthesis significantly up to 99 and 92%, respectively, and star anise and cardamom by 41 and 23%, respectively. The results of this study suggest the use of whole spices rather than their essential oils for controlling fungal and mycotoxin contamination in food grains.

scholarly journals The effect of Propolis on inhibition of Aspergillus parasiticus growth, aflatoxin production and expression of aflatoxin biosynthesis pathway genes

2020 ◽  
Vol 18 (1) ◽  
pp. 297-302 ◽  
Author(s):  
Hamideh Mahmoodzadeh Hosseini ◽  
Siavash Hamzeh Pour ◽  
Jafar Amani ◽  
Sima Jabbarzadeh ◽  
Mostafa Hosseinabadi ◽  
...  
Keyword(s):  
Aspergillus Parasiticus ◽  
Aflatoxin Production ◽  
Biosynthesis Pathway ◽  
Aflatoxin Biosynthesis

Growth and Aflatoxin Production by Aspergillus parasiticus in a Medium Containing Plant Hormones, Herbicides or Insecticides

1987 ◽  
Vol 50 (12) ◽  
pp. 1044-1047 ◽  
Author(s):  
R. S. FARAG ◽  
M. A. EL-LEITHY ◽  
A. E. BASYONY ◽  
Z. Y. DAW
Keyword(s):  
Acetic Acid ◽  
Gibberellic Acid ◽  
Plant Hormones ◽  
Aspergillus Parasiticus ◽  
Synthetic Medium ◽  
Fungal Growth ◽  
Aflatoxin Production ◽  
Inhibitory Effect ◽  
Indol Acetic Acid ◽  
Acid Herbicides

The effect of some widely used plant hormones (indol-3-acetic acid and gibberellic acid), herbicides (gramoxone, stomp and treflan) and insecticides (malathion, actellic and guthion) on Aspergillus parasiticus growth and aflatoxin production in a synthetic medium was studied. Addition of indol acetic acid to the medium increased aflatoxin production more than gibberellic acid. Treflan at 5, 10 and 20 ppm levels caused a highly significant stimulatory effect on A. parasiticus growth and aflatoxin production. In contrast, stomp at 10 and 20 ppm produced the reverse effect. Guthion, an insecticide, caused a marked decrease in fungal growth and aflatoxin production. The inhibitory effect of insecticides under study on both fungal growth and aflatoxin production in effectiveness followed the sequence: guthion>actellic>malathion. At the recommended application rate (10 ppm), with the exception of indol acetic acid and treflan, all compounds suppressed mold growth and aflatoxin production.

Aspergillus parasiticus Growth and Aflatoxin Synthesis on Florunner Peanuts Grown in Gypsum-Supplemented Soil

1993 ◽  
Vol 56 (7) ◽  
pp. 593-594 ◽  
Author(s):  
CINDY L. C. REDING ◽  
MARK A. HARRISON ◽  
CRAIG K. KVIEN
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Fungal Biomass ◽  
Aspergillus Parasiticus ◽  
Calcium Supplementation ◽  
Fungal Growth ◽  
Growing Season ◽  
Aflatoxin Production ◽  
Layer Chromatography

Five levels of gypsum supplementation (0, 550, 1100, 2200, and 4400 kg ha−1) were applied to peanut fields 35 d after planting. After the growing season, peanuts were harvested, ground, and inoculated with 1 × 107 Aspergillus parasiticus (NRRL 5139) conidia. After 14 d at 25°C, aflatoxin was extracted and quantified by thin-layer chromatography. Fungal growth was assayed using a modified chitin assay. Peanuts from gypsum-supplemented fields at each level of supplementation supported significantly less aflatoxin production when compared to control peanuts (no calcium supplementation). Results from the chitin assay showed a decrease in fungal biomass which correlated with the decreased aflatoxin synthesis.

Growth and Aflatoxin Production by Aspergillus parasiticus NRRL 2999 in the Presence of Lactic Acid and at Different Initial pH values

1987 ◽  
Vol 50 (11) ◽  
pp. 940-944 ◽  
Author(s):  
FATHY E. EL-GAZZAR ◽  
GULAM RUSUL ◽  
ELMER H. MARTH
Keyword(s):  
Lactic Acid ◽  
Aflatoxin B1 ◽  
High Performance ◽  
Aspergillus Parasiticus ◽  
Ph Value ◽  
Aflatoxin Production ◽  
Reversed Phase ◽  
Ph Values ◽  
Initial Ph ◽  
Medium Weight

Twenty-five milliliters of glucose-yeast-salts medium containing 0, 0.5, 0.75, 1.0, 1.5 and 2.0% lactic acid with an initial pH of 3.5 or 4.5 were inoculated with 1 ml of a spore suspension containing 106 conidia of Aspergillus parasiticus NRRL 2999 and incubated at 28°C for 10 d. The pH of the medium, weight of mycelium and aflatoxin production were determined after 3, 7, and 10 d of incubation. Amounts of aflatoxin produced were determined using reversed-phase high-performance liquid chromatography. Cultures grown in the presence of 0.5 and 0.75% lactic acid at an initial pH of 4.5 produced more aflatoxin B1 than did the other cultures at the end of 3 d of incubation. This was not true for aflatoxin G1; with increasing concentrations of lactic acid, cultures produced decreasing amounts of aflatoxin G1. Also, cultures growing in the medium with an initial pH of 3.5 produced more aflatoxin B1 in the presence of lactic acid at the end of 3 d of incubation than did control cultures. Cultures growing in the presence of 0.5 and 0.75% lactic acid produced the most aflatoxin. Maximum amounts of aflatoxin G1 were produced after 7 d of incubation, with cultures growing in the presence of 0.5 and 0.75% lactic acid producing the most. Lactic acid did not inhibit growth (mycelium weight) of cultures in the medium with initial pH values of 3.5 or 4.5 except there was a slight decrease in mycelial weight when the medium contained 0.5% lactic acid and had an initial pH value of 3.5.

scholarly journals Inhibitory Effect of Vitamin C on Aspergillus parasiticus Growth and Aflatoxin Gene Expression

2018 ◽  
Author(s):  
Maryam Akbari Dana ◽  
Sasan Rezaie ◽  
Parivash Kordbacheh ◽  
Roshanak Daei Ghazvini ◽  
Maryam Moazeni ◽  
...  
Keyword(s):  
Gene Expression ◽  
Vitamin C ◽  
Aspergillus Parasiticus ◽  
Human Life ◽  
Fungal Spores ◽  
Aflatoxin Production ◽  
Inhibitory Effect ◽  
Hplc Method ◽  
Agricultural Products ◽  
Expression Level

Abstract Objective: Aflatoxin is known as one of the most important mycotoxins that threatens of human life. The toxin is produced by Aspergillus species which are common cause of contamination of agricultural products. For this reason, the use of organic compounds has always been considered in order to inhibit the growth of fungi and production of toxin. The aim of this study was to investigate the effect of vitamin C on the growth rate of fungi and the level of aflR gene expression (gene responsible for aflatoxin production). Material and method: At first, Aspergillus parasiticus ATCC15517 was cultured in SDA medium containing vitamin C with concentrations of 200, 100, 50, 25, 12.5, 6.25, 3.1 mg / ml at 28 ° C for 72 hours. Then, the amount of aflatoxin produced in the presence of vitamin C was measured by HPLC method. Finally, by extracting the DNA of cultured samples, the aflR gene expression level was evaluated by real-time PCR at different concentrations of vitamin C. Result: The results showed that the deformation of mycelium was started in medium with 50 mg / ml of vitamin C and only fungal spores were observed at higher concentrations. The results of measurement of toxin showed that the level of total aflatoxin and the subset of B 1, B 2, G 1 and G 2 were 5.9, 1.9, 0.2, 3.5 and 0.3 ppm in the presence of vitamin, respectively. While without the presence of vitamin C, these values were 207.5, 73.6, 4.5, 123.4, 6 ppm, respectively. Measuring the expression level of aflR genes, showed that at a concentration of 25 mg / ml of vitamin C, the level of gene expression is down 68%, and at the concentration of 50 mg / ml, the level of gene expression is decreased up to 81%. Conclusion: This study showed that vitamin C, as a human-compatible compound, could be considered as a good way to keep agricultural products from fungal aflatoxin.

A Study of Aflatoxin Production by Aspergillus Flavus Growing on Wallboard

1997 ◽  
Vol 2 (4) ◽  
pp. 36-42 ◽  
Author(s):  
Carol Y. Rao ◽  
Richard C. Fink ◽  
Linda B. Wolfe ◽  
Daniel F. Liberman ◽  
Harriet A. Burge
Keyword(s):  
Aspergillus Flavus ◽  
High Performance ◽  
Building Materials ◽  
Culture Media ◽  
Fungal Growth ◽  
Aflatoxin Production ◽  
Culture Collection ◽  
Indoor Environments ◽  
Toxigenic Fungi ◽  
Aflatoxin Concentration

The potential for exposure to mycotoxins in indoor environments is of increasing concern. In order to evaluate the potential for mycotoxin production by toxigenic fungi growing on water-damaged building materials, two aflatoxin producing strains of Aspergillus flavus (American Type Culture Collection 16875 and 15547) were inoculated onto culture media, plain wallboard, and vinyl wallpapered wallboard (cellulose-based and wheat-based wallpaper paste) and incubated at high relative humidity and room temperature for up to 16 weeks. Each sample was extracted with 60% methanol and aflatoxins in the crude extract were collected by immunoaffinity chromatography and quantified by fluorometry. Analysis by high performance liquid chromatography was performed for confirmation. Varying degrees of fungal growth were evident on all tested substrate types. Up to 4800 ppb of aflatoxin was detected when strain ATCC 16875 was grown on potato dextrose agar. However, when inoculation was standardized to minimize initial aflatoxin concentration in the inoculum, aflatoxin production was not detected on any wallboard sample under any of the incubation conditions provided. The presence of a toxigenic fungal strain on an indoor substrate does not necessarily indicate that the fungus is producing mycotoxins and our data provide evidence that wet wallboard is unlikely to provide appropriate conditions for aflatoxin production.

Growth of and Aflatoxin Production by Aspergillus parasiticus in a Medium Containing Potassium Chloride or a Mixture of Potassium Chloride and Sodium Chloride

1986 ◽  
Vol 49 (11) ◽  
pp. 880-885 ◽  
Author(s):  
GULAM RUSUL ◽  
FATHY E. EL-GAZZAR ◽  
ELMER H. MARTH
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Sodium Chloride ◽  
Potassium Chloride ◽  
High Performance ◽  
Aspergillus Parasiticus ◽  
Dry Weight ◽  
Aflatoxin Production ◽  
Lag Phase ◽  
Reverse Phase

Twenty-five milliliters of glucose-yeast-salts medium containing 0, 2, 4, 6, 8 and 10% KCl or a mixture of NaCl (%) and KCl (%) (0:0, 1.5:0.5, 3.25:0.75, 4.75:1.25, 6.5:1.5, and 8:2) was inoculated with 1 ml of a spore suspension containing 106 conidia of Aspergillus parasiticus NRRL 2999 and incubated at 28°C for 10 d. The pH, dry weight of mycelium and aflatoxin production were determined after 3, 7 and 10 d of incubation. Amounts of aflatoxin produced were determined using reverse-phase high-performance liquid chromatography (HPLC). The mold growing in the presence of 0, 2 and 4% KCl produced maximum amounts of aflatoxin after 3 d, whereas in the presence of 6, 8 and 10% KCl it did so after 7 d. This trend was also true when the mold grew in the presence of mixtures of NaCl and KC1. Amounts of aflatoxin produced decreased with increasing concentrations of KCl or of the mixture of NaCl and KCl. The mycelial dry weight increased with increasing concentrations of KCl or the mixture of NaCl and KCl, although there was an extended lag phase at higher concentrations of both treatments.

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