Aflatoxin and cyclopiazonic acid production by Queensland isolates of Aspergillus flavus and Aspergillus parasiticus

1989 ◽  
Vol 40 (2) ◽  
pp. 395 ◽  
Author(s):  
BJ Blaney ◽  
MA Kelly ◽  
AL Tyler ◽  
MD Connole
Keyword(s):  
Aspergillus Flavus ◽  
Acid Production ◽  
Aspergillus Parasiticus ◽  
Cyclopiazonic Acid ◽  
Aflatoxin Production ◽  
Quantitative Correlation ◽  
Low Concentrations ◽  
Maize Meal ◽  
High Concentrations ◽  
Relative Prevalence

The production of aflatoxins (AFB1, AFB2, AFG1, AFG2) and cyclopiazonic acid (CPA) by 50 Queensland isolates of thc Aspergillusflavus-Aspergillus parasiticus group was examined for the purposes of chemotaxonomy and toxicology. lsolatcs were cultured on Czapek Dox agar at 28�C and examined microscopically after 5, 7 and 10 days. Conidial heads were classified as either bearing phialides only or phialidcs and metulac, while conidia were classified according to degree of roughness. Isolates were also sown onto maize meal incubated at 28�C for 28 days and assayed for aflatoxins and CPA. A. flavus types were classified as having biseriate sterigmata in 40-100% of cases and slightly to moderately rough conidia, whereas A. paraszticus types were those with 0-35% biseriate sterigmata and spikey conidia. Of the 38 isolates classed as A. flavus, 34 produced CPA (range 1-70 mg kg-1). Three isolates produced neither aflatoxins (t0.02 mg kg-1) nor CPA (< 1 mg kg-1). Seven produced CPA but no aflatoxins. The remaining 28 isolates produced AFB1 (0.02-280 mg kg-1); seven of these produced low concentrations of AFG1(0.02-0.08 mg kg-1); and only one did not produce CPA. There was no quantitative correlation between CPA and aflatoxin production by the A. fIavus isolates. Of the 12 isolates classed as A. parasiticus, none produced CPA; all produced AFB1 (4-400 mg kg-1); all produced high concentrations of AFG1 (1-400 mg kg-1). The relative prevalence of the two fungi in Queensland is discussed as a guide to the likelihood of aflatoxin and CPA contamination of different agricultural commodities.

Effects of Some Spices on Acid Production by Starter Cultures

1979 ◽  
Vol 42 (7) ◽  
pp. 572-576 ◽  
Author(s):  
LAURA L. ZAIKA ◽  
JOHN C. KISSINGER
Keyword(s):  
Liquid Medium ◽  
Lactobacillus Plantarum ◽  
Acid Production ◽  
Bacterial Population ◽  
Starter Culture ◽  
Starter Cultures ◽  
Red Pepper ◽  
Bacterial Counts ◽  
Low Concentrations ◽  
High Concentrations

Ginger, red pepper, mustard, mace, cinnamon and clove were examined to determine their effects on growth of and acid production by a starter culture containing Lactobacillus plantarum and Pediococcus cerevisiae in a liquid medium. At 4, 8, and 12 g/l levels all spices except clove stimulated acid production by the starter bacteria but did not stimulate increases in bacterial population. Clove was inhibitory to the starter bacteria at and above the 4 g/l level, but low concentrations (0.5 – 2.0 g/l) stimulated acid production. High concentrations of cinnamon (8 and 12 g/l) delayed acid production, but bacterial counts were similar to those of the control.

Effects of Potassium Sorbate on Growth and Aflatoxin Production by Aspergillus parasiticus and Aspergillus flavus1

1983 ◽  
Vol 46 (11) ◽  
pp. 940-942 ◽  
Author(s):  
LLOYD B. BULLERMAN
Keyword(s):  
Aspergillus Flavus ◽  
Yeast Extract ◽  
Aflatoxin B1 ◽  
Spore Germination ◽  
Mycelial Growth ◽  
Aspergillus Parasiticus ◽  
Aflatoxin Production ◽  
Potassium Sorbate ◽  
Mycelial Mass ◽  
Yeast Extract Sucrose

Growth and aflatoxin production by selected strains of Aspergillus parasiticus and Aspergillus flavus in the presence of potassium sorbate at 12°C were studied. Potassium sorbate at 0.05, 0.10 and 0.15% delayed or prevented spore germination and initiation of growth, and slowed growth of these organisms in yeast-extract sucrose broth at 12°C. Increasing concentrations of sorbate caused more variation in the amount of total mycelial growth and generally resulted in a decrease in total mycelial mass. Potassium sorbate also greatly reduced or prevented production of aflatoxin B1 by A. parasiticus and A. flavus for up to 70 d at 12°C. At 0.10 and 0.15% of sorbate, aflatoxin production was essentially eliminated. A 0.05% sorbate, aflatoxin production was greatly decreased in A. flavus over the control, but only slightly decreased in A. parasiticus.

Enhanced Aflatoxin Production by Aspergillus flavus and Aspergillus parasiticus after Gamma Irradiation of the Spore Inoculum

1980 ◽  
Vol 43 (1) ◽  
pp. 7-9 ◽  
Author(s):  
A. F. SCHINDLER ◽  
A. N. ABADIE ◽  
R. E. SIMPSON
Keyword(s):  
Radiation Dose ◽  
Aspergillus Flavus ◽  
Gamma Rays ◽  
Aspergillus Parasiticus ◽  
Aflatoxin Production ◽  
Distilled Water ◽  
Mycotoxin Production ◽  
High Production ◽  
Dose Levels ◽  
Medium Dose

Distilled water plus 0.1% surfactant suspensions of spores of Aspergillus flavus and Aspergillus parasiticus were exposed to several radiation levels of cobalt-60 gamma rays. Spores of A. flavus isolate M-141 were exposed to radiation levels of approximately 16, 90 and 475 Krads and inoculated onto a sterile rice substrate which was then monitored for aflatoxin production. In this initial trial with A. flavus M-141, aflatoxins B1 and M production on rice increased as radiation dose increased. At the highest dose, this increase was more than 50 times higher than the non-irradiated controls. Spores of an aflatoxin G1-producing A. parasiticus isolate, M-1094, were exposed to 90, 215 and 430 Krads and resulted in increased production of aflatoxins G1, B1, and M. Aflatoxin production by M-1094 was highest at the low and medium dose levels. Irradiation of spores of this isolate with 430 Krads produced no observable spore germination or growth on rice and no detectable aflatoxin after 1 week of incubation at 27 C. A typical colonies from irradiated spores were selected and their mycotoxin production was determined. Increase in aflatoxin production by these strains, as compared to non-irradiated controls, was 67:1 for aflatoxin B1, 136:1 for B2, and 138:1 for M. This potential for greatly increased mycotoxin production must be considered when food is irradiated or when a high production of aflatoxins is desired.

Effect of ochratoxin A on aflatoxin production by Aspergillus parasiticus

1991 ◽  
Vol 69 (1) ◽  
pp. 16-17 ◽  
Author(s):  
M. Serafini ◽  
S. Foddai ◽  
S. Pieretti ◽  
L. Tomassini ◽  
M. Nicoletti
Keyword(s):  
Key Words ◽  
Ochratoxin A ◽  
Aspergillus Parasiticus ◽  
Aflatoxin Production ◽  
High Concentrations ◽  
Key Words Aspergillus ◽  
Stimulation Of

The effect of ochratoxin A on growth and aflatoxin production by Aspergillus parasiticus was investigated. High concentrations had a significant effect, causing stimulation of aflatoxin production. Key words: Aspergillus parasiticus, aflatoxin production, ochratoxin A.

Temperature Limits for Production of Aflatoxin by Twenty-five Isolates of Aspergillus flavus and Aspergillus parasiticus

1977 ◽  
Vol 40 (1) ◽  
pp. 39-40 ◽  
Author(s):  
A. F. SCHINDLER
Keyword(s):  
Aspergillus Flavus ◽  
Aspergillus Parasiticus ◽  
Agar Medium ◽  
Aflatoxin Production ◽  
Wort Agar

Aflatoxicogenic isolates of Aspergillus were tested for their aflatoxin production after 8 weeks of growth on wort agar medium at high (41, 46 ± 1 C) and low (2, 7 ± 0.5 C) temperatures. Controls were grown at approximately 22 C, a temperature known to be favorable for aflatoxin production. There were two replications of each treatment. All replicate cultures of the 25 isolates grown at 22 C were positive for aflatoxin. Aflatoxins were not detected in wort agar when cultures were incubated at other test temperatures. It appears that both Aspergillus flavus and Aspergillus parasiticus will not produce aflatoxins when grown at ⩽ 7.5 C or at ⩾ 40 C.

scholarly journals A comparative analysis of mycotoxin contamination of supermarket and premium brand pelleted dog food in Durban, South Africa

2017 ◽  
Vol 88 ◽  
Author(s):  
Sanil D. Singh ◽  
Anil A. Chuturgoon
Keyword(s):  
South Africa ◽  
Comparative Analysis ◽  
Aspergillus Fumigatus ◽  
South African ◽  
Ochratoxin A ◽  
Aspergillus Flavus ◽  
Aspergillus Parasiticus ◽  
Marketing Channel ◽  
Dog Food ◽  
Low Concentrations

Dry pelleted dog food in the South African market is available via supermarkets, pet stores (standard brands [SBs]) and veterinary channels (premium brands [PBs]). For the purpose of this study, the supermarket channel included the cheaper quality foods and PBs were sold via the veterinary channel (n = 20). These feeds were analysed for four main mycotoxins (aflatoxins [AF], fumonisin [FB], ochratoxin A [OTA] and zearalenone [ZEA]) using standard welldescribed extraction, characterisation and quantitation processes. Irrespective of the brand or marketing channel, all foods were contaminated with fungi (mainly Aspergillus flavus, Aspergillus fumigatus and Aspergillus parasiticus) and mycotoxins (most prevalent being aflatoxins and fumonisins). This was observed in all 20 samples irrespective of the marketing channel or perceived quality. Also, many samples within each marketing channel failed the 10 ppb limit for aflatoxin set by regulations in South Africa. Although fumonisin was detected in all samples, a single sample failed the Food and Drug Administration (FDA) limit of 100 ppb. Both OTA and ZEA were found at low concentrations and were absent in some samples. This study suggested that higher priced dog food does not ensure superior quality or that it is free from contamination with fungi or mycotoxins. However, analysis of the more expensive PBs did reveal contamination concentrations lower than those of the SBs.

Polymerase Chain Reaction–Mediated Characterization of Molds Belonging to the Aspergillus flavus Group and Detection of Aspergillus parasiticus in Peanut Kernels by a Multiplex Polymerase Chain Reaction

2002 ◽  
Vol 65 (5) ◽  
pp. 840-844 ◽  
Author(s):  
RUEY-SHYANG CHEN ◽  
JWU-GUH TSAY ◽  
YU-FEN HUANG ◽  
ROBIN Y.-Y. CHIOU
Keyword(s):  
Polymerase Chain Reaction ◽  
Aspergillus Flavus ◽  
Aspergillus Parasiticus ◽  
Regulatory Protein ◽  
Aflatoxin Production ◽  
Dna Fragments ◽  
Chain Reaction ◽  
Target Dna ◽  
Polymerase Chain ◽  
Aspergillus Flavus Group

The Aspergillus flavus group covers species of A. flavus and Aspergillus parasiticus as aflatoxin producers and Aspergillus oryzae and Aspergillus sojae as koji molds. Genetic similarity among these species is high, and aflatoxin production of a culture may be affected by cultivation conditions and substrate composition. Therefore, a polymerase chain reaction (PCR)-mediated method of detecting the aflatoxin-synthesizing genes to indicate the degree of risk a genotype has of being a phenotypic producer was demonstrated. In this study, 19 strains of the A. flavus group, including A. flavus, A. parasiticus, A. oryzae, A. sojae, and one Aspergillus niger, were subjected to PCR testing in an attempt to detect four genes, encoding for norsolorinic acid reductase (nor-1), versicolorin A dehydrogenase (ver-1), sterigmatocystin O-methyltransferase (omt-1), and a regulatory protein (apa-2), involved in aflatoxin biosynthesis. Concurrently, the strains were cultivated in yeast-malt (YM) broth for aflatoxin detection. Fifteen strains were shown to possess the four target DNA fragments. With regard to aflatoxi-genicity, all seven aflatoxigenic strains possessed the four DNA fragments, and five strains bearing less than the four DNA fragments did not produce aflatoxin. When peanut kernels were artificially contaminated with A. parasiticus and A. niger for 7 days, the contaminant DNA was extractable from a piece of cotyledon (ca. 100 mg), and when subjected to multiplex PCR testing using the four pairs of primers coding for the above genes, they were successfully detected. The target DNA fragments were detected in the kernels infected with A. parasiticus, and none was detected in the sound (uninoculated) kernels or in the kernels infected with A. niger.

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