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

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.

1985 ◽  
Vol 48 (2) ◽  
pp. 162-165 ◽  
Author(s):  
LLOYD B. BULLERMAN

Effects of potassium sorbate on growth and ochratoxin production by Aspergillus ochraceus NRRL 3174 and Penicillium sp. isolated from cheese were studied. Potassium sorbate at 0.05, 0.10 and 0.15% delayed or prevented spore germination and initiation of growth, and decreased the rate of growth of both organisms in yeast-extract sucrose (YES) broth at 12°C. However, at 25°C germination and growth of A. ochraceus was more rapid. Increasing concentrations of sorbate caused more variation in the amount of total mycelial growth of Penicillium sp. and generally resulted in a decrease in total mycelial mass. Potassium sorbate also greatly reduced or prevented production of ochratoxin by Penicillium sp. for up to 70 d at 12°C. At 0.05 and 0.10% sorbate, ochratoxin production was greatly reduced over the control, and was eliminated at 0.15%. Overall, ochratoxin production by Penicillium sp. in the presence of sorbate was very low or eliminated. On the other hand, A. ochraceus responded somewhat differently to sorbate. At 12°C, A. ochraceus was similarly inhibited by all three levels of sorbate, and did not produce ochratoxin. When incubated at 25°C, A. ochraceus grew quite readily and appeared to produce greater amounts of ochratoxin in the presence of sorbate, especially at the 0.05% level. Considerably higher levels of ochratoxin were produced at 0.05% sorbate than the control, and somewhat higher levels were obtained at 0.10 and 0.15% sorbate.


2016 ◽  
Vol 10 (1) ◽  
pp. 197-201 ◽  
Author(s):  
Roshanak Daie Ghazvini ◽  
Ebrahim Kouhsari ◽  
Ensieh Zibafar ◽  
Seyed Jamal Hashemi ◽  
Abolfazl Amini ◽  
...  

Food and feedstuff contamination with aflatoxins (AFTs) is a serious health problem for humans and animals, especially in developing countries. The present study evaluated antifungal activities of two lactic acid bacteria (LAB) against growth and aflatoxin production of toxigenic Aspergillus parasiticus. The mycelial growth inhibition rate of A. parasiticus PTCC 5286 was investigated in the presence of Bifidobacterium bifidum PTCC 1644 and Lactobacillus fermentum PTCC 1744 by the pour plate method. After seven days incubation in yeast extract sucrose broth at 30°C, the mycelial mass was weighed after drying. The inhibitory activity of LAB metabolites against aflatoxin production by A. parasiticus was evaluated using HPLC method. B. bifidum and L. fermentum significantly reduced aflatoxin production and growth rate of A. parasiticus in comparison with the controls (p≤0.05). LAB reduced total aflatoxins and B1, B2, G1 and G2 fractions by more than 99%. Moreover, LAB metabolites reduced the level of standard AFB1, B2, G1 and G2 from 88.8% to 99.8% (p≤0.05). Based on these findings, B. bifidum and L. fermentum are recommended as suitable biocontrol agents against the growth and aflatoxin production by aflatoxigenic Aspergillus species.


1987 ◽  
Vol 50 (11) ◽  
pp. 959-963 ◽  
Author(s):  
ABDELMAJID MAHJOUB ◽  
LLOYD B. BULLERMAN

Growth and aflatoxin production by Aspergillus parasiticus NRRL 2999 and Aspergillus flavus NRRL 6555 were studied on fresh olives, fresh olives supplemented with nutrients, and fresh olives treated with heat, lye, and freezing temperatures. Studies were also done on yeast extract sucrose agar (YESA) either mixed with chopped fresh olives or made with aqueous extracts of fresh and treated olives. Samples were incubated at 25°C for 7 d. Olive paste supplemented with zinc and sucrose supported little growth and no aflatoxin B1 production. Amino acids, yeast extract, and a combination of zinc, carbohydrate, and amino acids exhibited extensive growth and moderate amounts of aflatoxin. Fresh and frozen olive pastes supported poor growth and no aflatoxin production. Heat- and lye-treated olives supported extensive growth and little aflatoxin production. Heavy growth and moderate amounts of aflatoxin B1 were supported by YES A mixed with olive pastes. YES A made with aqueous extracts of olives supported extensive growth and moderate toxin production, except on YES A made with extract from frozen olives which exhibited poor growth and low toxin amounts. A. flavus grew similarly to A. parasiticus but was unable to produce any aflatoxin except on heat- and lye-treated olives, where traces were detected. Olives are a poor substrate for mold development and may contain inhibiting substances against growth and aflatoxin production.


1999 ◽  
Vol 62 (4) ◽  
pp. 414-417 ◽  
Author(s):  
J. J. FAN ◽  
J. H. CHEN

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.


2015 ◽  
Vol 3 (1) ◽  
pp. 6-9 ◽  
Author(s):  
Geeta Rajbhandari Shrestha ◽  
Amin Udhin Mridha

Aflatoxins are the potent mycotoxins produced by Aspergillus flavus, which is hepatotoxic causing hepatocellular carcinoma. A. flavus produces sufficient amount of Aflatoxin B1 under favourable environments. Inhalation of spores and use of Aflatoxin B1, contaminated food by Aspergillus spp., could transfuse the toxins in the blood streams. The presence of these toxins in body fluid can be detected by immunological assays and which provides an effective technique for the diagnosis of the disease caused by A. flavus. Aflatoxins producing strain of A. flavus were screened in Aflatoxin Producing Medium. Production of Aflatoxin B1 by A. flavus was studied in different parameters such as incubation periods, temperatures, pH variations, sucrose concentration in Yeast Extract Sucrose medium and different natural media such as par-boiled rice, corn and groundnuts. The detection of toxins was done by TLC using silica gel (Merk) coated plates and confirmative test was done by Association of Official Analytical Chemists (AOAC) method. Presence and quantization was done by Enzyme Linked Immunosorbent Assay (ELISA) technique. Highest amount of Aflatoxin B1 was reported 68.56 ng/ml by ELISA in synthetic medium (Yeast Extract Sucrose) with 2% sucrose, pH 5.5, on 14th days of incubation, at 28±1°C (p-value 0.05). Similarly, highest amount was recorded in groundnuts (121.20ng/g) by ELISA and (500ng/kg) by TLC methods. ELISA is one of the most efficient methods used for detection and diagnosis of human diseases cause due to exposure of Aflatoxin B1 and A. flavus.Nepal Journal of Biotechnology. Dec. 2015 Vol. 3, No. 1: 6-9


1994 ◽  
Vol 57 (3) ◽  
pp. 256-258 ◽  
Author(s):  
M. L. ABARCA ◽  
M. R. BRAGULAT ◽  
G. CASTELLÁ ◽  
F. J. CABAÑES

The mycoflora of 69 samples of animal mixed feeds were studied. Fungal counts ranged from 102 to 108 CFU/g, the lowest counts corresponding to the samples of rabbit feeds. Seventy-one fungal species belonging to 26 genera were identified. The pre- dominant species were Aspergillus flavus, Fusarium moniliforme, and Penicillium chrysogenum. Thirty-six strains of A. flavus and one strain of A. parasiticus were screened for aflatoxin production in yeast extract-sucrose medium. The final pH, weight of mycelium, and production of aflatoxins were determined after 14 days of incubation. Five strains (13.5%) were aflatoxigenic. No statistical differences were observed in mycelial dry weights and final pH between aflatoxin-producing strains and nonaflatoxigenic strains.


1988 ◽  
Vol 51 (2) ◽  
pp. 139-144 ◽  
Author(s):  
HASSAN GOURAMA ◽  
LLOYD B. BULLERMAN

Potassium sorbate at 500, 1000 and 1500 μg/ml delayed initiation of growth and sporulation by Aspergillus ochraceus 0L24 in yeast extract-sucrose (YES) broth at 15°C, 25°C and 35°C. At 25°C, sporulation and growth were more rapid. Potassium sorbate at 500 μg/ml resulted in an increase in mycelial weight, but at 1000 and 1500 μg/ml the mycelial mass was decreased. Potassium sorbate also reduced or prevented production of penicillic acid, especially at 15 and 35°C. Natamycin at 1, 10 and 20 μg/ml delayed initiation of growth and sporulation in YES broth. At 20 μg of natamycin/ml, mycelial growth was inhibited by 80 to 100% and penicillic acid production was completely inhibited. Growth and penicillic acid production on olive paste by A. ochraceus in the presence of potassium sorbate and natamycin showed that sorbate at 1500, 3000, and 6000 μg/g delayed growth and sporulation. Also, the extent of growth was greatly reduced by 3000 and 6000 μg of potassium sorbate/g. Penicillic acid production was reduced over the control at all the potassium sorbate levels. At 6000 μg of sorbate/g, no penicillic acid was detected after 21 d of incubation. Natamycin at 85, 175, and 350 μg/g delayed growth and sporulation by A. ochraceus on olive paste. Increasing levels of natamycin resulted in decreased growth. Production of penicillic acid was also decreased by natamycin, 350 μg of natamycin/g decreased penicillic acid production by 96%.


1993 ◽  
Vol 56 (8) ◽  
pp. 718-721 ◽  
Author(s):  
AGUSTIN A. ARINO ◽  
LLOYD B. BULLERMAN

Spores of Aspergillus parasiticus strain NRRL 2999 were inoculated into yeast extract sucrose broth containing different levels of iprodione (0, 1, 3, 5, 10, 15, and 20 (μg/ml) and incubated at 25°C for 4, 7, 10, 14, and 21 d. Iprodione inhibited mold growth and subsequent toxin production, beginning at the 5 μg/g level up to 7 d of incubation. Results showed that as the iprodione level increased, more time was required by the organism to initiate mycelial development. At any given time, the lower the iprodione level, the more dry mycelial weight and aflatoxin production (B1, B2, G1, and G2) were observed.


1976 ◽  
Vol 39 (3) ◽  
pp. 170-174 ◽  
Author(s):  
M. D. NORTHOLT ◽  
C. A. H. VERHULSDONK ◽  
P. S S. SOENTORO ◽  
W. E. PAULSCH

The effect of water activity (aw) on growth and aflatoxin production by Aspergillus parasiticus NRRL 2999 was determined using submerged cultures in which the aw was adjusted by addition of glycerine, glucose, or a mixture of salts. At a sub-optimal aw aflatoxin production was low in the glycerol and glucose media while no strong inhibition of mycelial growth occurred. A similar effect was obtained in surface cultures on agar media in which the aw was adjusted by addition of glycerine or sucrose. The effect of a sub-optimal temperature was the reverse; compared to inhibition of mycelial growth in surface cultures, the effect on aflatoxin production was slight. No detectable quantities of aflatoxin B1 were formed at 0.83 aw and at 10 C nor at four combinations of higher aw and temperature. The aw was measured by a recently developed device using the dewpoint principle.


1999 ◽  
Vol 62 (10) ◽  
pp. 1223-1227 ◽  
Author(s):  
NACHMAN PASTER ◽  
ZHOU LECONG ◽  
MAZAL MENASHROV ◽  
RONI SHAPIRA

The effects of nisin and propionic acid (PA) on aflatoxin production and on mycelial growth and spore germination of the mycotoxigenic fungi Aspergillus parasiticus, A. ochraceus, and Fusarium moniliforme were investigated. The growth of A. ochraceus was completely inhibited on media containing PA with nisin in concentrations of 0.05% PA with 1,000 ppm nisin, and 0.1% PA with 500 or 1,000 ppm nisin. The growth of both F. moniliforme and A. parasiticus was completely inhibited by PA with nisin at a concentration of 0.1% PA with 1,000 ppm nisin. Nisin alone caused a significant increase in mycelial growth when applied to A. ochraceus at 500 or 1,000 ppm and when applied to A. parasiticus at 1,000 ppm. Spore germination of A. ochraceus was completely inhibited on media containing 0.1% PA with 500 or 1,000 ppm nisin. Spores of F. moniliforme failed to germinate in 0.05% PA with 500 or 1,000 ppm nisin, whereas spores of A. parasiticus did not germinate on media containing 0.1% PA with 1,000 ppm nisin. For all three fungi tested, the inhibitory effect on mycelial growth was found to be fungistatic rather than fungicidal. The combined treatment of PA with nisin produced better fungistatic activity than treatment involving either material alone. Nisin, applied alone, did not stimulate aflatoxin production (expressed by μg toxin/mg mycelium), but the combined treatment at certain concentrations was inhibitory to aflatoxin B1 or G1. The production of aflatoxin G1, but not of B1, was stimulated in 0.05% PA with 1,000 ppm nisin and on media containing 0.1% PA with 100 ppm nisin. Nisin is currently applied in foods to prevent spoilage induced by bacteria but not by mold. The results of the present study indicate that a combined treatment of nisin in small concentrations of PA might be useful in preventing mold damage in certain foods and stored grain.


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