Aflatoxin Production in a Meat Mix Model System in the Presence of Pediococcus and Lactobacillus

1992 ◽  
Vol 55 (8) ◽  
pp. 583-587 ◽  
Author(s):  
ROSA H. LUCHESE ◽  
JOSÉ F. P. MARTINS ◽  
WILKIE F. HARRIGAN

The effect on aflatoxin production by Aspergillus parasiticus of eight individual strains of Pediococcus and Lactobacillus was determined. The study was conducted in an axenic cultural system in which irradiated meat was employed in the formulation of a meat medium. The medium composition and incubation temperatures were simulations of Brazilian salami processing conditions. All single cultures of A. parasiticus supported aflatoxin production. More aflatoxin was produced in samples treated by the addition of lactic acid than in nontreated ones. Aflatoxin was not detected when A. parasiticus was grown with lactic acid bacteria, although visible mold growth was observed in all such cultures.

2017 ◽  
Vol 38 (1) ◽  
Author(s):  
Rooholla Ghanbari ◽  
Ebrahim Molaee Aghaee ◽  
Sassan Rezaie ◽  
Gholamreza Jahed Khaniki ◽  
Mahmoud Alimohammadi ◽  
...  

2021 ◽  
Vol 12 ◽  
Author(s):  
Cleide Oliveira de Almeida Møller ◽  
Luisa Freire ◽  
Roice Eliana Rosim ◽  
Larissa Pereira Margalho ◽  
Celso Fasura Balthazar ◽  
...  

The increased consumption of plant-based foods has intensified the concern related to mycotoxin intoxication. This study aimed to investigate the effect of selected lactic acid bacteria (LAB) strains on the growth of Aspergillus parasiticus NRRL 2999 and its production of aflatoxin (AF). The ability of the heat-killed (100°C for 1 h) LAB strains to bind aflatoxin M1 (AFM1) in milk and aflatoxin B1 (AFB1), ochratoxin A (OTA), and zearalenone (ZEN) in potassium phosphate buffer (PPB) was also evaluated in vitro. Ten LAB strains were tested individually, by inoculating them simultaneously with the fungus or after incubation of the fungus for 24 or 48 h at 25°C. Double layer yeast extract sucrose (YES) agar, de Man Rogosa and Sharpe (MRS) agar, and YES broth were incubated for 7 days at 25°C to follow the development of the fungus. Levilactobacillus spp. 3QB398 and Levilactobacillus brevis 2QB422 strains were able to delay the growth of A. parasiticus in YES broth, even when these strains were inoculated 24 h after the fungus. The inhibitory effect of these LAB strains was confirmed by the reduction of fungus colony size, suggesting dominance of LAB by competition (a Lotka-Voltera effect). The production of AFB1 by A. parasiticus was inhibited when the fungus was inoculated simultaneously with Lactiplantibacillus plantarum 3QB361 or L. plantarum 3QB350. No AFB1 was found when Levilactobacillus spp. 2QB383 was present, even when the LAB was inoculated 48 h after the fungus. In binding studies, seven inactivated LAB strains were able to promote a reduction of at least 50% the level of AFB1, OTA, and ZEN. This reduction varied depending on the pH of the PPB. In milk, however, only two inactivated LAB strains were able to reduce AFM1, with a reduction of 33 and 45% for Levilactobacillus spp. 3QB398 (Levilactobacillus spp.) and L. brevis 2QB422, respectively. Nevertheless, these results clearly indicate the potential of using LAB for mycotoxin reduction.


1981 ◽  
Vol 44 (10) ◽  
pp. 736-741 ◽  
Author(s):  
AHMED E. YOUSEF ◽  
ELMER H. MARTH

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.


1994 ◽  
Vol 58 (8) ◽  
pp. 1412-1415 ◽  
Author(s):  
Osamu Tanaka ◽  
Hidetoshi Kimura ◽  
Eiji Takahashi ◽  
Seiya Ogata ◽  
Sadahiro Ohmomo

2020 ◽  
Vol 47 (2) ◽  
pp. 119-129
Author(s):  
Mirjana Grujović ◽  
Katarina Mladenović ◽  
Ljiljana Čomić

In this paper, the effect of different temperatures, pH, and NaCl concentration on the growth of autochthonous lactic acid bacteria isolated from traditionally made Serbian cheese (Sokobanja area) was investigated by using the spectrophotometric method. Growth of tested Lactobacillus (Lb. fermentum, Lb. plantarum, and Lb. brevis) and Lactococcus lactis subsp. lactis biovar. diacetylactis five isolates were better in acidic pH, while the growth of Enterococcus isolates (E. durans, E. faecium, and E. faecalis) was better in basic pH, at 37 °C. At 4 °C after 24 h, none of the tested bacteria showed growth. Since the autochthonous isolates were tolerant to a tested range of dairy processing conditions, further studies need to include the characterization of enzymatic activity of selected isolates, as well as the ability to use these isolates like starter cultures or food supplements in dairy or non-dairy products.


1986 ◽  
pp. 184-184
Author(s):  
Z. Libudzisz ◽  
B. Mansfeld ◽  
E. Kacki ◽  
H. Oberman

1996 ◽  
Vol 59 (7) ◽  
pp. 739-745 ◽  
Author(s):  
GUILLERMO L. KOCIUBINSKI ◽  
PABLO F. PÉREZ ◽  
MARIA C. AÑÓN ◽  
GRACIELA L. DE ANTONI

A rapid method of screening for lactic acid bacteria with high inhibitory power was developed. The methodology employed was the agar-diffusion assay, which was standardized for the indicator strain, medium composition, and incubation conditions. The assay was performed in nutrient agar at 30°C with 108 spores of Bacillus subtilis per plate as indicator strain. The inhibition produced by supernatants of lactic acid bacteria cultures harvested at stationary phase was determined. The inhibitory powers of different strains were compared with a standard curve obtained with racemic lactic acid. Results obtained with lactic acid and supernatants of bacterial cultures demonstrate that the diameter of the inhibition zone (d) was related to the pH by the exponential relation d = a exp (− b pH). Results obtained with strains that produced inhibitory substances other than lactic acid could not be fitted into the standard linear curves obtained in the plot of ln d versus pH of lactic acid.


1995 ◽  
Vol 1 (2-3) ◽  
pp. 129-136 ◽  
Author(s):  
M.L. Silva ◽  
F.X. Malcata ◽  
T.A. Hogg

The independent and combined effects of the addition of tartaric acid, the addition of pectinases, and the time of fermentation (and the material of the container) on the specific rates of death of lactic acid bacteria and yeasts were experimentally evaluated through a full (or fractional) two-way factorial design for pomace fermentation from the Alvarinho (and the Loureiro) varieties. Microbes present in the pomace prior to fermentation were identified in a preliminary fashion. Knowledge of the behavior of the microflora in grape pomace as a function of each major processing parameter during the step of anaerobic fermentation is important in attempts to eventually standardize and optimize the manufacture of these distilled beverages.


1994 ◽  
Vol 57 (2) ◽  
pp. 136-140 ◽  
Author(s):  
SHAO W. FANG ◽  
CHIN F. LI ◽  
DANIEL Y. C. SHIH

The inhibitory effect of chitosan, a deacetylated form of chitin, on the growth of Aspergillus niger and the aflatoxin production of Aspergillus parasiticus was evaluated. The inhibitory effect of chitosan against A. niger was increased as the chitosan concentration was increased from 0.1 to 5.0 mg/ml (pH 5.4). At concentrations of 4.0 or 5.0 mg/ml, chitosan was less effective than potassium sorbate in inhibiting the growth of A. niger. The greatest inhibitory effect of chitosan against A. parasiticus was found at 3.0–5.0 mg/ml. In addition, chitosan could completely prevent aflatoxin production by A. parasiticus at the concentration of 4.0–5.0 mg/ml. Chitosan (2.0 and 5.0 mg/ml) induced considerable leakage of UV-absorbing and proteinaceous material of A. niger at pH 4.8. Using the response surface methodology, a second order polynomial model was derived and used to predict the number of days to obtain visible mold growth under various combinations of chitosan concentrations and °Brix in candied kumquat. The results showed that there was no significant difference in shelf-life extension of candied kumquat at chitosan concentration of 3.5–6.5 mg/ml. However, °Brix had a significant effect on shelf life. Candied kumquat with 6.0 mg/ml chitosan concentration and 61.9° Brix had a predicted mold-free shelf life of 65.3 d.


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