Potential Mold Growth, Aflatoxin Production, and Antimycotic Activity of Selected Natural Spices and Herbs

1981 ◽  
Vol 64 (4) ◽  
pp. 955-960
Author(s):  
Gerald C Llewellyn ◽  
Mary Lee Burkett ◽  
Thomas Eadie
Keyword(s):  
Mycelial Growth ◽  
Sesame Seed ◽  
Strain Differences ◽  
Aflatoxin Production ◽  
Mold Growth ◽  
Sterile Water ◽  
Natural Materials ◽  
Antimycotic Activity ◽  
Celery Seed ◽  
Toxigenic Strains

Abstract Ground spices and herbs are evaluated as substrates for mycelial growth, sporulation, and aflatoxin production. Three toxigenic strains of Aspergilli, A. flavus ATCC 15548, A. flavus NRRL 3251, and A. parasiticus NRRL 2999, were cultured on moist, commercially packaged herbs and spices. All substrates used were ground and included thyme, celery seed, oregano, cinnamon, ginger, caraway seed, clove, mustard, sesame seed, and rosemary leaves. Following inoculation of the natural materials in sterile bottles containing sterile water, the cultures were incubated 30 days at 23 ± 4°C. Not all strains of Aspergilli grew, sporulated, or produced toxins. There were definite strain differences and definite substrate differences for the variables evaluated. Sesame seed produced toxins B1, G1, and G2, with a mean of 167 ppm for 3 strains. A. flavus ATCC 15548 was the greatest overall toxin producer followed by A. partsiticus NRRL 2999 and A. flavus NRRL 3251. Ginger and rosemary leaves were also substantial producer-substrates. Mustard, caraway seed, and celery seed were judged as intermediate-producing substrates. Absolute antimycotic substrates were cinnamon and clove. Antiaflatoxigenic substrates were thyme and oregano. Mustard also may be antimycotic. Aflatoxins B1 and G1 were the more commonly found toxins

Growth and Synthesis of Aflatoxin by Aspergillus parasificus in the Presence of Ginseng Products

1983 ◽  
Vol 46 (3) ◽  
pp. 210-215 ◽  
Author(s):  
JAERIM BAHK ◽  
ELMER H. MARTH
Keyword(s):  
Aflatoxin B1 ◽  
Mycelial Growth ◽  
Aflatoxin Production ◽  
Mold Growth ◽  
Red Ginseng ◽  
Maximum Accumulation ◽  
Ginseng Saponin ◽  
White Ginseng

Red ginseng saponin (0.36%) inhibited mycelial growth, sporulation and aflatoxin production by Aspergillus parasificus during 9 d at 28°C. The mold caused no change in pH of the medium when it contained red ginseng saponin or ginseng tea (9%). Most ginseng products permitted mycelial growth and production of aflatoxin B1, but inhibited production of aflatoxin G1. However, when compared to the control, aflatoxin production by A. parasiticus was reduced by the presence in the medium of most of the ginseng products that were tested, Ginseng tea (9%) resulted in a higher index of maximum accumulation of aflatoxins per interval of mold growth than occurred in the control. Red ginseng was more effective than white ginseng for inhibiting mold growth and aflatoxin production.

Susceptibility of Strawberries, Blackberries, and Cherries to Aspergillus Mold Growth and Aflatoxin Production

1982 ◽  
Vol 65 (3) ◽  
pp. 659-664 ◽  
Author(s):  
Gerald C Llewellyn ◽  
Thomas Eadie ◽  
William V Dashek
Keyword(s):  
Acetic Acid ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Mycelial Growth ◽  
Methylene Chloride ◽  
Aflatoxin Production ◽  
Solvent System ◽  
Mold Growth ◽  
Tlc Plates ◽  
Layer Chromatography

Abstract The susceptibility of blackberries, cherries, and strawberries to Aspergillus growth and aflatoxin production has been examined. Three aflatoxigenic isolates of Aspergillus, A. flavus ATCC 15548 and NRRL 3251 as well as A. parasiticus NRRL 2999, were cultured on homogenates of the fruits for 14 days at 28 ± 2°C. Percent mycelial growth and spore infestation were determined each day with a calibrated grid. At day 14 each culture was frozen at –5°C until aflatoxins were extracted with methylene chloride and water. Aflatoxins were separated by thin layer chromatography (TLC) with benzene-methanol-acetic acid (90 + 5 + 5). This extraction and solvent system provided satisfactory separations of the aflatoxins and was free of background interference on the TLC plates. Although all fruits served as substrates for both Aspergillus growth and aflatoxin production, cherries appeared to be a more favorable substrate than did blackberries, and the latter was more favorable than strawberries. Whereas A. flavus produced both B1 and G1 on all substrates, it yielded B2 and G2 only on cherries. Although A. parasiticus NRRL 2999 synthesized B1, B2, G1, and G2 on both blackberries and cherries, no aflatoxins were detected on strawberries. In contrast, A. flavus NRRL 3251 failed to produce detectable levels of aflatoxin on any substrate. All substrates supported both mycelial growth and subsequent sporulation with cherries > blackberries > strawberries.

Inhibition of Aflatoxin-Producing Fungi by Welsh Onion Extracts

1999 ◽  
Vol 62 (4) ◽  
pp. 414-417 ◽  
Author(s):  
J. J. FAN ◽  
J. H. CHEN
Keyword(s):  
Aspergillus Flavus ◽  
Mycelial Growth ◽  
Ethanol Extract ◽  
Aflatoxin Production ◽  
Inhibitory Effects ◽  
Welsh Onion ◽  
Extract Concentration ◽  
Ph Values ◽  
Ethanol Extracts ◽  
Yeast Extract Sucrose

Welsh onion ethanol extracts were tested for their inhibitory activity against the growth and aflatoxin production of Aspergillus flavus and A. parasiticus. The survival of spores of A. flavus and A. parasiticus depended on both the extract concentration and the exposure time of the spores to the Welsh onion extracts. The mycelial growth of two tested fungi cultured on yeast extract–sucrose broth was completely inhibited in the presence of the Welsh onion ethanol extract at a concentration of 10 mg/ml during 30 days of incubation at 25°C. The extracts added to the cultures also inhibited aflatoxin production at a concentration of 10 mg/ml or permitted only a small amount of aflatoxin production with extract concentration of 5 mg/ml after 2 weeks of incubation. Welsh onion ethanol extracts showed more pronounced inhibitory effects against the two tested aflatoxin-producing fungi than did the same added levels of the preservatives sorbate and propionate at pH values near 6.5.

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.

Inhibition of Mold Growth and Aflatoxin Production by Lactobacillus spp1

1990 ◽  
Vol 53 (3) ◽  
pp. 230-236 ◽  
Author(s):  
ANJANI KARUNARATNE ◽  
ELENORA WEZENBERG ◽  
LLOYD B. BULLERMAN
Keyword(s):  
Lactobacillus Acidophilus ◽  
Ph Effect ◽  
Aflatoxin Production ◽  
Individual Species ◽  
Mold Growth ◽  
Microbial Competition ◽  
Growing Cell ◽  
Metabolic Products ◽  
Different Strains ◽  
Silage Inoculant

The effect of three individual species of lactobacilli (Lactobacillus acidophilus, L. bulgaricus, and L. plantarum) and a commercial silage inoculant, containing three different strains of the same species, on growth and aflatoxin production of A. flavus subsp. parasiticus NRRL 2999 was determined. The study was done in three substrates; a liquid semi-synthetic broth, rice, and corn. The effect of the growing cell masses of the lactobacilli as well as the effect of metabolic products contained in cell free filtrates were determined in the liquid medium. The cells were effective in preventing growth of the mold, and bacterial metabolites were effective in reducing the amount of aflatoxin produced, although growth was not affected. The prevention of growth that was observed was determined to be relative to a pH effect and microbial competition; however, the lower levels of aflatoxin obtained in the presence of cell free supernatant culture fluids could not be explained on the basis of pH or competition. Mold growth was not affected by the presence of the silage inoculant on the rice and corn. However, increased levels of aflatoxin B1 were observed in the presence of the silage inoculant on rice, and decreased levels of aflatoxin G1 were observed on the presence of the silage inoculant on corn.

Aflatoxigenic Potential for Aspergilli on Sucrose Substrates

1980 ◽  
Vol 63 (3) ◽  
pp. 622-625
Author(s):  
Gerald C Llewellyn ◽  
Hudson C Jones ◽  
James E Gates ◽  
Thomas Eadie
Keyword(s):  
Carbon Source ◽  
Mycelial Growth ◽  
Aspergillus Parasiticus ◽  
Growth Period ◽  
Aflatoxin Production ◽  
Food And Drink

Abstract Sucrose concentrations of 3, 10, 20, and 30% in Czapek Dox broth served as the carbon source for growth, aflatoxin production, and sporulation for Aspergillus parasiticus NRRL 2999 and A flavus NRRL 3557, 5862, and 5013. All cultures produced mycelial growth and sporulated in all sucrose concentrations during the 12-day growth period. The area of mycelial mat coverage per hour increased directly with increased sugar concentrations. The 20 and 30% sucrose concentrations inhibited mycelial growth for 5862. The 30% sucrose cultures of 3557 and 5862 failed to produce detectable levels of aflatoxins. All other isolates produced B1 and G1 in an approximately 4:1 ratio in all sucrose concentrations. Only 2999 was a substantial producer of aflatoxin in all 4 sucrose cultures, ranging from 72 to 96 μg/mL medium. A. flavus 5013 produced the most toxin, 144 and 126 μg/mL medium in the 10 and 20% sucrose cultures, respectively. The 10 and 20% sucrose cultures were most conducive to aflatoxin production. Since these sucrose levels correspond closely to the levels in many food and drink products, especially home-made products, care and attention should be taken to keep them free of aflatoxigenic spores. Extensive mycelial growth and sporulation, even in aflatoxigenic strains, do not necessarily result in comparably high aflatoxin levels. Routine extraction and quantitation procedures for aflatoxin were applicable and provided satisfactory results.

Growth and Synthesis of Aflatoxin by Aspergillus parasiticus in the Presence of Sorbic Acid

1981 ◽  
Vol 44 (10) ◽  
pp. 736-741 ◽  
Author(s):  
AHMED E. YOUSEF ◽  
ELMER H. MARTH
Keyword(s):  
Incubation Period ◽  
Aspergillus Parasiticus ◽  
Sorbic Acid ◽  
Aflatoxin Production ◽  
Potassium Sorbate ◽  
Mold Growth ◽  
Early Stages ◽  
Cumulative Data ◽  
The Media ◽  
Growth Ph

Two media [basal (M1) and enriched (M2)] containing potassium sorbate (0–300 ppm as sorbic acid) were inoculated with spores (104 – 106/flask) of Aspergillus parasiticus and incubated for 5 days at 28 C. The greater the amount of sorbate added, the higher was the pH of the media after incubation and the smaller was the yield of mold mycelium. Intermediate amounts of sorbate sometimes resulted in greater accumulation of aflatoxin than when media were free of sorbate. Sorbate more effectively inhibited mold growth and aflatoxin production in medium M2 than M1 and when the small rather than the large inoculum was used. A second trial was done with 106 or 105 spores/flask of M2 (ca. 27 ml) and 105 spores/flask of M2 (ca. 27 ml) containing sorbate (200 ppm of sorbic acid). Cumulative data for mold growth. pH and content of aflatoxin in the medium showed that relative effects of different treatments changed during the incubation period. An index to measure the capacity of molds to synthesize aflatoxins was developed. Application of the index indicates that sorbate delayed mold growth but did not inhibit biosynthesis of aflatoxin. The ability to synthesize aflatoxin was greatest in the early stages of mold growth and then decreased linearly as mold growth progressed.

scholarly journals Genetic Profiling of Aspergillus Isolates with Varying Aflatoxin Production Potential from Different Maize-Growing Regions of Kenya

Toxins ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 467
Author(s):  
Richard Dooso Oloo ◽  
Sheila Okoth ◽  
Peter Wachira ◽  
Samuel Mutiga ◽  
Phillis Ochieng ◽  
...  
Keyword(s):  
Internal Transcribed Spacer ◽  
Genetic Factors ◽  
Its Region ◽  
Aflatoxin Production ◽  
Fungal Species ◽  
Aflatoxin Biosynthesis ◽  
Production Potential ◽  
Genetic Profiling ◽  
Obvious Association ◽  
Toxigenic Strains

Highly toxigenic strains of Aspergillus flavus have been reported to frequently contaminate maize, causing fatal aflatoxin poisoning in Kenya. To gain insights into the environmental and genetic factors that influence toxigenicity, fungi (n = 218) that were culturally identified as A. flavus were isolated from maize grains samples (n = 120) from three regions of Kenya. The fungi were further characterized to confirm their identities using a PCR-sequence analysis of the internal transcribed spacer (ITS) region of rDNA which also revealed all of them to be A. flavus. A subset of 72 isolates representing ITS sequence-based phylogeny cluster and the agroecological origin of maize samples was constituted for subsequent analysis. The analysis of partial calmodulin gene sequences showed that the subset consisted of A. flavus (87%) and Aspergillus minisclerotigenes (13%). No obvious association was detected between the presence of seven aflatoxin biosynthesis genes and fungal species or region. However, the presence of the aflD and aflS genes showed some association with aflatoxin production. The assessment of toxigenicity showed higher aflatoxin production potential in A. minisclerotigenes isolates. Given that A. minisclerotigenes were mainly observed in maize samples from Eastern Kenya, a known aflatoxin hotspot, we speculate that production of copious aflatoxin is an adaptative trait of this recently discovered species in the region.

Effect of Temperature, Water Activity and Other Toxigenic Mold Species on Growth of Aspergillus flavus and Aflatoxin Production on Corn, Pinto Beans and Soybeans

1988 ◽  
Vol 51 (5) ◽  
pp. 361-363 ◽  
Author(s):  
MARY W. TRUCKSESS ◽  
LEONARD STOLOFF ◽  
PHILIP B. MISLIVEC
Keyword(s):  
Aspergillus Flavus ◽  
Aflatoxin Production ◽  
Aflatoxin Contamination ◽  
Penicillium Citrinum ◽  
Effect Of Temperature ◽  
Mold Growth ◽  
Additional Water ◽  
Pinto Beans ◽  
Native Strains ◽  
Temperature Water

Portions of corn, a commodity in which aflatoxin is frequently found, were held at 16, 26 and 32°C after the moisture contents were adjusted to achieve water activities (aw) ranging from too low to ample for support of mold growth. Suspensions of mold spores from toxigenic cultures of Aspergillus flavus, A. ochraceus, Penicillium citrinum, P. cyclopium and P. urticae were added to the test portions, either as A. flavus alone, as A. flavus with one of the other molds or as a mixture of all 5 species. Additional water was used to obtain the proper moisture levels. A temperature of 16°C was generally too low for aflatoxin production by either the added or native strains of A. flavus, although the mold was able to grow at 16°C at aw values as low as 0.80, 0.77 and 0.85 on corn, soybeans and pinto beans, respectively. Aflatoxin production was essentially the same at 26 and 32° C with limiting aw values in the range of 0.85–0.89. Limiting aw values for mold growth at 26 and 32°C were 0.73, 0.69 and 0.75 for corn, soybeans and pinto beans, respectively. This study provided no evidence that substrate suitability at limiting temperatures and aw levels is a factor in the observed difference in the risk of aflatoxin contamination for these commodities. The study did indicate that the associated mold flora, when the seed is exposed to mold invasion, is a risk determinant.

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