ABSTRACT
14C-Fumonisin B(1) (FB(1)) was produced by Fusarium proliferatum M-5991 in modified Myro liquid medium and purified to >95% purity with a specific activity of 1.7 mCi/mmol. Nine male and nine female F344/N rats were each dosed by gavage with 0.69 micromol of (14)C-FB(1), (14)C-hydrolyzed FB(1), or (14)C-FB(1)-fructose/kg body weight. Urinary excretion of (14)C-FB(1) and (14)C-FB(1)-fructose was 0.5% and 4.4% of the total dose, respectively, and was similar between male and female rats. Urinary excretion of (14)C-hydrolyzed HFB(1) was significantly greater (P > 0.05) in female rats as compared with male rats (17.3% vs 12.8% of the total dose, respectively). There were no significant (P > 0.05) differences in biliary excretion of the three fumonisin compounds with a mean of 1. 4% of the dose excreted at 4 h after dosing. Lesser amounts continued to be excreted up to 9.25 h after dosing. Although biliary excretion of the (14)C-FB(1), (14)C-hydrolyzed FB(1), and (14)C-FB(1)-fructose was similar, increased urinary excretion of the (14)C-hydrolyzed FB(1) as compared to (14)C-FB(1) and (14)C-FB(1)-fructose indicated a greater absorption of the hydrolyzed form.
Subject(s)
Carboxylic Acids/pharmacokinetics , Carcinogens, Environmental/pharmacokinetics , Food Preservation , Fructose/pharmacokinetics , Fumonisins , Mycotoxins/pharmacokinetics , Animals , Carbon Radioisotopes , Carboxylic Acids/urine , Female , Fructose/analogs & derivatives , Fructose/urine , Humans , Male , Mycotoxins/urine , Rats , Rats, Inbred F344 , Rats, Sprague-Dawley , Sex FactorsABSTRACT
This study investigated the role of intracellular and extracellular bacteria in the production of paralytic shellfish toxins by dinoflagellated algal cells. Three strains of the toxic dinoflagellate species, Alexandrium tamarense, were purified by external bacteria using penicillin G (Pen. G) at levels of 500 and 1000 p.p.m. Levels of toxicity of the resulting purified dinoflagellate cultures were similar to those of the original strains contaminated with external bacteria, indicating that the external bacteria had no influence on toxicity. No bacterial colony forming units (cfu) arose from disruption of algal cells derived from penicillin-treated cultures, indicating that intracellular bacteria were not responsible for the toxicity of cultures.
Subject(s)
Bacillus/metabolism , Dinoflagellida/metabolism , Dinoflagellida/microbiology , Marine Toxins/biosynthesis , Moraxella/metabolism , Animals , Anti-Bacterial Agents , Anti-Infective Agents/pharmacology , Bacillus/drug effects , Bacillus/isolation & purification , Eukaryota/metabolism , Eukaryota/microbiology , Male , Marine Toxins/toxicity , Mice , Mice, Inbred BALB C , Moraxella/drug effects , Moraxella/isolation & purification , Penicillin G/pharmacology , Yeasts/drug effects , Yeasts/isolation & purificationABSTRACT
Fusarium proliferatum strain M5991 cultures were grown in shake flasks containing modified Myro (MM) medium (MgSO4 reduced to 0.5 g/L) plus 0, 0.25, 0.50, 0.75, 1.00, or 1.25% (v/v) hot-water and corn-hull-extract (CHE) for 69 days. After 4 days of incubation, shake flask liquid cultures with 0.75, 1.00, and 1.25% (v/v) CHE showed a reduction in pH from 6.0 to 2.6 and consumed sucrose at > 6.3 g/L/d. After 69 days of incubation, the same shake flask cultures produced over 7.8 g/L cell mass and over 990 mg/L fumonisin B1 (FB1). A minimum CHE level of 0.75% was recommended for enhanced FB1 production by F. proliferatum strain M5991. During three serial (10, 12, and 12 L) batch fermentations in MM medium + 1.00% (v/v) CHE (first batch only), F. proliferatum strain M5991 produced FB1 concentrations of 619, 659, and 375 mg/L after 35, 47, and 52 days of incubation, respectively. By analysis, a total yield of 20 g FB1 was obtained from three serial batch fermentations.