Johanna F. Alberts

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Aflatoxin contamination of food and grain poses a serious economic and health problem worldwide, but particularly in Africa. Aflatoxin B(1) (AFB(1)) is extremely mutagenic, toxic and a potent carcinogen to both humans and livestock and chronic exposure to low levels of AFB(1) is a concern. In this study, the biodegradation of aflatoxin B(1) (AFB(1)) by(More)
Biological degradation of aflatoxin B(1) (AFB(1)) by Rhodococcus erythropolis was examined in liquid cultures and in cell-free extracts. Dramatic reduction of AFB(1) was observed during incubation in the presence of R. erythropolis cells (17% residual AFB(1) after 48 h and only 3-6% residual AFB(1) after 72 h). Cell-free extracts of four bacterial strains,(More)
The enzymatic degradation of aflatoxin B(1) (AFB(1)) by white rot fungi through laccase production was investigated in different liquid media. A significant (P<0.0001) correlation was observed between laccase activity and AFB(1) degradation exhibited by representatives of Peniophora and Pleurotus ostreatus cultivated in minimal salts (MSM) (r=0.93) and(More)
The kinetics of the production of fumonisin B1 (FB1) by Fusarium moniliforme MRC 826 in corn cultures was investigated as a function of fungal growth at various incubation temperatures. The growth rate of F. moniliforme, as measured by ergosterol concentration, was higher at 25 degrees C than at 20 degrees C, reaching a stationary phase after 4 to 6 weeks(More)
Kinetics of growth and fumonisin production by Fusarium moniliforme MRC 826 in corn "patty" cultures were investigated, and a technique was developed for the production of [14C]fumonisin B1 ([14C]FB1) by using L-[methyl-14C]methionine as the precursor. A significant (P < 0.01) correlation exists between fungal growth and FB1 (r = 0.89) and FB2 (r = 0.87)(More)
Fumonisin B1 (FB1), a toxic and carcinogenic secondary metabolite of the fungus Fusarium moniliforme Sheldon, was administered either by i.v. injection or by gavage to vervet monkeys (Cercopithecus aethiops). FB1 dosed by i.v. injection to two female vervet monkeys was rapidly eliminated from plasma with a mean half-life during the elimination phase of 40(More)
Production of fumonlsins B1 (FB1) and B2 (FB2) by 5 lyophillzation batches ofFusarium moniliforme strain MRC 826 was studied in several liquid media and vermlculite supplemented with liquid media. In addition the effect of different parameters including pH, Inert material, shake versus stationary cultures as well as different carbon sources on the(More)
The biliary excretion of the mycotoxin fumonisin B1 (FB1), produced by the fungus Fusarium moniliforme Sheldon, has been measured in male Wistar rats. After ip injection of a solution of FB1 (7.5 mg/kg body weight), 67% of the applied dose was recovered in bile over a 24-hr period, 88% of this recovery being excreted in the first 4 hr after dosing. In(More)
An in vitro study on the interaction and biotransformation of the [14C]fumonisin B mycotoxins was conducted, using primary rat hepatocyte cultures and subcellular enzyme preparations. At the same concentration, fumonisin B2 (FB2) exhibited a higher cytotoxicity and specific binding to primary rat hepatocytes than fumonisin B1 (FB1). However, if the(More)
The extraction and purification methods used in the maleyl derivatization HPLC technique was evaluated with respect to the pH of the extraction mixture, the extraction solvent and the purification methods used in order to determine optimum conditions for quantification of fumonisins B1, B2, and B3 in corn cultures. The highest recovery of the three(More)