Production of fumonisins by Fusarium moniliforme strains isolated from corn grain

Fusarium moniliforme is the predominant fusarium species in the grain mycoflora of corn grown in Northern Caucasus, accounting for 95% of fusarium isolates. Eighty-five Fusarium moniliforme strains were grown on grain substrate and checked for the presence of fumonisins (B1 + B2 + B3) by indirect solid-phase enzyme immunoassay (EIA). All strains were capable of producing fumonisins (0.95 to 32,000 mg/kg). Strains sampled in the Krasnodar krai produced the highest fumonisin levels (averaging 5490 mg/kg).     

Production of Fumonisins by Fusarium moniliforme Cultures Isolated from Jimsonweed in Mississippi

Eight Fusarium spp. were isolated from greenhouse-grown jimsonweed (Datura stramonium L.) in Mississippi in 1990. Four isolates of Fusarium moniliforme were obtained and when grown on autoclaved rice, produced 115 to 3,200 mg/kg fumonisin B₁, (FB₁). Other fumonisin-related compounds, such as FB₂, FB₃ and FB₄ were also produced at levels of 240, 210 and 160 mg/kg, respectively. F. semitectum (1 isolates) was negative for production of fumonisin and other phyto-toxins. F. oxysporutn (1 isolate) produced only 3.5 g/kg moniliformin. This is the first report of production of fumonisins by F. moniliforme isolated from weeds such as jimsonweed.     

Fusarium moniliforme Sheldon — Pathogenicity to Wheat Seedlings and Ability to Produce Fumonisins

All 17 examined Polish isolates of Fusarium moniliforme Sheldon [syn. F. verticillioides (Sacc.) Nirenberg], originating from wheat, maize and barley kernels, exhibited pathogenicity to wheat seedlings of the cultivar ‘Almari’ (5 isolates-very strong, 3 strong, 3 medium, 5 weak and only one very weak). The same isolates were able to produce the mycotoxins fumonisins on rice under laboratory conditions. Fumonisin B₁ (FB1) was detected in concentrations ranging from 1.3 to 2240mg/kg and fumonisin B₂(FB₂) from 0.7 to 600 mg/kg. The yield of the fumonisins produced in vitro was not related to the pathogenicity of individual isolates.     

Production of fumonisins byFusarium species of Taiwan

Twenty-nineFusarium species isolated from various sources in different districts of Taiwan were tested for their ability to produce fumonisins in corn cultures. OnlyFusarium moniliforme produced fumonisin B₁ (FB₁) and fumonisin B₂ (FB₂). The finding that the other 28Fusarium species produced neither FB₁ nor FB₂ is preliminary because only one strain per species was studied. The detection of FB₁ and FB₂ in cultures ofF. moniliforme was demonstrated by TLC and HPLC, and FB₁ was further confirmed by mass spectrometry. In a separate experiment, in which 38 strains ofF. moniliforme were tested for fumonisins, approximately 66% (25/38) produced FB₁ and/or FB₂. Of the 25 strains, 14 produced only FB₁ and 11 produced both FB₁ and FB₂, and the amounts of FB₁ and FB₂ produced by different strains varied greatly. This is the first report that fumonisins are found in corn cultures experimentally infected withF. moniliforme strains from Taiwan. It is safe to assume that fumonisin producing strains ofF. moniliforme are widely distributed among the economic crops such as corn, rice, sugarcane, and sorghum throughout the Island.Abbreviations FB₁ Fumonisin B₁ - FB₂ Fumonisin B₂ - OPA o-phthalidialdehyde     

Developmental toxicity of fumonisin in Syrian hamsters

The effects of fumonisin on development of Syrian hamster fetuses were studied using fumonisin B₁ and B₂ extracted fromFusarium moniliforme corn-culture and purified fumonisin B₁. A significant increase in litters with fetal deaths occurred with the high doses of purified (18 mg FB₁/kg) and culture-extracted (18 mg FB₁ plus 4.5 mg FB₂) fumonisin. It is concluded that prenatal exposure to fumonisin on days 8 and 9 of gestation is detrimental to fetal hamster survivability but does not induce clinical maternal intoxication at these doses. Equivalent doses of fumonisin B₁, whether from culture-extract or pure solution produced similar results.     

Natural occurrence of Fusarium species and fumonisin-production by toxigenic strains isolated from poultry feeds in Argentina

Fusarium species and fumonisin production by toxigenic strains were investigated. During 1996–1998, 158 samples of poultry feeds were collected from a factory located in the department of Río Cuarto Córdoba province, Argentina. The most common species of Fusarium were F. moniliforme (60.7%) and F. nygamai (35.4%) followed by F. semitectum, F. subglutinans, F. proliferatum, F. dlamini, F. solani, F. oxysporum and F. napiforme. Fungal counts ranged from 1 × 10³ to 8 × 10⁵ CFU/g with mean values from 1.5 × 10³ to 2.3 × 10⁵ CFU/g. The highest counts were for F. dlamini, F. subglutinans, F. moniliforme and F. nygamai. Strains of F. moniliforme, F. nygamai, and F. proliferatum were screened for their potential to produce fumonisin B₁ (FB₁), fumonisin B₂ (FB₂) and fumonisin B₃ (FB₃) in corn grain. The samples were analysed using a modified high performance liquid chromatography method. The strains assayed, 43 strains, produced three fumonisins. There was a high degree of variability in the quantities of FB₁, FB₂, and FB₃ produced. The toxin produced in highest levels by the majority of the strains was FB₁. The range of concentration varied from 5.4 to 3,991, 1.01 to 189 and 0.4 to 765 ppm per gram of corn for FB₁, FB₂ and FB₃ respectively. The toxigenic pattern of strains was normal, although two strains of F. moniliforme produced exceptionally high concentrations of FB₃ and minor concentrations of FB₂ and FB₁. This is the first report from Argentina on Fusarium species in poultry feeds and fumonisin production by these strains.This revised version was published online in October 2005 with corrections to the Cover Date.     

A new fumonisin from solid cultures of Fusarium moniliforme

A new fumonisin has been isolated from Fusarium moniliforme isolate MRC826 grown on corn. It was shown by NMR and mass spectrometry to be an isomer of fumonisin B₂ that has free hydroxyl groups at C-3 and C-10 instead of the normal C-3 and C-5. This new fumonisin was detected in cultures of most isolates of F. moniliforme that were examined and was usually present at concentrations similar to those of fumonisin B₂. Two isolates of F. moniliforme that produce significantly higher levels of this new isomer were identified.Abbreviations ELEM equine leukoencephalomalacia Mention of companies or products by name does not imply their endorsement by the US Department of Agriculture over others not cited.     

Mycoflora and fumonisin-producing strains ofFusarium moniliforme in mixed poultry feeds and component raw material

In a survey of the mycoflora and mycotoxins in foods and feeds, 66 samples of mixed poultry feeds and some component raw materials were investigated. Fungal counts ranged from < 10² to 1.3 × 10⁶ CFU/g.Fusarium spp. counts ranged from 10² to 1.0 × 10⁶ CFU/g. TheFusarium spp. strains isolated were screened for their potential to produce fumonisin B₁ (FB₁) and fumonisin B₂ (FB₂) in maize cultures. Samples and maize cultures were analysed for FB₁ and FB₂ using TLC and fluorescamine-derivative HPLC. No fumonisins were detected in the samples (<6 ppm).Fusarium moniliforme was isolated in 59.1% of samples, and 97.4% of the strains produced FB₁ and 79.4% of strains produced FB₂ in maize cultures. Some isolates produced higher FB₁ and FB₂ levels than the reference strainF. moniliforme MRC 826.     

Fumonisins — Importance and occurence of a new group of mycotoxins

This paper describes the importance of fumonisins for human beings and animals and shows data for the occurence in food. Corn-based food samples (n = 299) purchased in the area of munich were analyzed for fumonisin content using an enzyme immunoassay. Fumonisins are mycotoxins produced byFusarium species, especially byFusarium moniliforme andFusarium proliferatum. Occurrence of fumonisins in corn and in cornbased foods and feeds has been reported from almost all over the world. In several animal species different diseases are traced back to fumonisin toxicosis. Fumonisin levels of 5–10 ppm inhorse feed induce “Equine Leucoencephalomalacia” and hepatic lesions. Hepatotoxic (10 150 ppm fumonisin in feed) and pneumotoxic (>150 ppm fumonisin in feed) effects have been reported for swine. Cattle and poultry appear to be less susceptible to fumonisins. Fumonisin B₁ Revels of 50 ppm in the diet of rats cause hepatotoxic and nephrotoxic effects, long time exposure results in hepatic cancer. A possible role of fumonisins in the etiology of human esophageal cancer is under discussion, although no direct causal evidence is known so far. The mode of action of the fumonisins is probably based on inhibition of sphingolipidbiosynthesis caused by the blockade of the enzyme sphyngosine (sphinganine)-N-acyltrans-ferase.     

Biosynthesis of labeled fumonisins in liquid cultures of Fusarium moniliforme

Fumonisins were readily produced in cultures of Fusarium moniliforme using a defined liquid medium. Addition of 200 mg of d₃-methyl L-methionine to 100-ml cultures of F. moniliforme gave increased overall yields and high levels of deuterium (²H) incorporation into fumonisin B₁. Approximately 90% of the resulting fumonisin B₁ contained 6 deuterium atoms, while 9% of the product contained 3 deuterium atoms. Deuterium was shown to be incorporated exclusively in the methyl groups of the fumonisin backbone. The addition of as little as 5 mg of labeled methionine stimulated fumonisin production, but only about 5% of the fumonisin produced contained 3 deuterium atoms.Abbreviations ELEM equine leukoencephalomalacia Mention of companies or products by name does not imply their endorsement by the US Department of Agriculture over others not cited.     

Phytotoxic effects of fumonisin B1 on maize seedling growth

Fumonisin B₁ toxin is produced by the fungusFusarium moniliforme Sheldon, which is systemic to maize (Zea mays L.) and maize seeds. The effects of zero to 100 parts per million fumonisin B₁ on the germination process of maize seeds was determined. The presence of fumonisin had no effect on percent seed germination, but fumonisin inhibited radicle elongation by up to 75% after 48 hours of imbibition. An analysis of amylase secretion in the maize endosperm indicated that fumonisins inhibited amylase production in the germinating seed. Isoelectric focusing of endosperm extracts indicated that secretion of the low pI class of amylases was affected more that other amylase isozymes. The results suggested that the presence of high levels of fumonisin in maize seed may have deleterious effects on seedling emergence.     

Absence of detectable fumonisins in the milk of cows fed Fusarium proliferatun (Matsushima) Nirenberg culture material

Fumonisins, a group of mycotoxins produced by the ubiquitous fungi Fusarium moniliforme and F. proliferatum, were first identified about eight years ago. They have been shown to cause a variety of health effects in animals, including epidemiological evidence of esophageal cancer in humans. Cattle are less sensitive to ill effects than horses and swine. Fumonisins are common contaminants of low quality grain fed to cattle. Culture material containing fumonisins (FB1, FB2, and FB3) was mixed into the total diet and fed for 14 days to two midlactation Jersey cows to determine if fumonisins are excreted in milk. The dietary equivalent of fumonisin was approximately 75 ppm and the two cows consumed an average of 3 mg fumonisin Bl /kg body weight (b wt)/day. Fumonisins were not detected in any of the milk samples by two analytical laboratories using methods with a sensitivity of 5 ng/ml. Except for transient diarrhea at the beginning of the contaminant feeding period and an increase in serum cholesterol, clinical and hematologie changes were not observed in the animals. The appearance or carry over of fumonisins from feed to milk in dairy cows does not appear to be significant and likely not a hazard or food safety concern for humans.     

A review and update of animal toxicoses associated with fumonisin-contaminated feeds and production of fumonisins by Fusarium isolates

During the 1989 corn harvest season, numerous reports of equine leukoencephalomalacia (ELEM) outbreaks and a pulmonary edema (PPE) syndrome in swine from several regions of the United States were received by the National Veterinary Services Laboratories (NVSL), Ames, Iowa. Previous and concurrent research linked Fusarium moniliforme and fumonisin-contaminated feeds to both diseases. Chemical and mycological investigations revealed fumonisin B₁ (FB₁) concentrations of 20 to 360 ppm in suspect swine feeds and 8 to 117 ppm in suspect equine feeds. Nonproblem feeds contained concentrations below 8 ppm. Fusarium moniliforme and Fusarium proliferatum were isolated from both problem and nonproblem equine and swine feeds. When cultured on autoclaved corn, the F. moniliforme and F. proliferatum isolates produced respective FB₁ and fumonisin B₂ (FB₂) that range from less than 5 to more than 2450 ppm and less than 5 to more than 1000 ppm, respectively. Isolates from both problem and nonproblem feeds produced high levels (greater than 500 ppm) in culture. Reported here is a review of chemical and mycological data resulting from the study of several cases of PPE and ELEM.     

Mycotoxin production by Aspergillus niger aggregate strains isolated from harvested maize in three Portuguese regions

BackgroundMaize is considered one of the crops more susceptible to mycotoxins in the world. Two of the mycotoxins commonly associated with maize are fumonisins and ochratoxin A. Aspergillus niger is a known producer of ochratoxin A and is easily found in maize. Recently, however, A. niger has been reported to produce as well fumonisins, mainly fumonisin B₂.AimsThe aim of this study was to isolate A. niger strains from maize samples collected in three Portuguese maize growing regions and to detect the production of both fumonisin B₂ and ochratoxin A.MethodsNinety five maize samples were collected, plated, and all observable Aspergillus section Nigri strains were isolated. Strains were morphologically characterized and mycotoxin production was determined by HPLC-FD.ResultsIsolations resulted in a total of 270 strains of black Aspergillus from 73 samples (77% of the samples). About 14% of those strains were found to produce ochratoxin A and 39% of the strains were found to produce fumonisin B₂.ConclusionsAn association between the production of these two mycotoxins could not be found and no conclusions could be taken whether the presence of A. niger aggregate strains will increase the risk of maize contamination with fumonisins and more specifically with fumonisin B₂.     

Incidence of Fusarium spp. and Levels of Fumonisin B1 in Maize in Western Kenya

Maize kernel samples were collected in 1996 from smallholder farm storages in the districts of Bomet, Bungoma, Kakamega, Kericho, Kisii, Nandi, Siaya, Trans Nzoia, and Vihiga in the tropical highlands of western Kenya. Two-thirds of the samples were good-quality maize, and one-third were poor-quality maize with a high incidence of visibly diseased kernels. One hundred fifty-three maize samples were assessed for Fusarium infection by culturing kernels on a selective medium. The isolates obtained were identified to the species level based on morphology and on formation of the sexual stage in Gibberella fujikuroi mating population tests. Fusarium moniliforme (G. fujikuroi mating population A) was isolated most frequently, but F. subglutinans (G. fujikuroi mating population E), F. graminearum, F. oxysporum, F. solani, and other Fusarium species were also isolated. The high incidence of kernel infection with the fumonisin-producing species F. moniliforme indicated a potential for fumonisin contamination of Kenyan maize. However, analysis of 197 maize kernel samples by high-performance liquid chromatography found little fumonisin B₁ in most of the samples. Forty-seven percent of the samples contained fumonisin B₁ at levels above the detection limit (100 ng/g), but only 5% were above 1,000 ng/g, a proposed level of concern for human consumption. The four most-contaminated samples, with fumonisin B₁ levels ranging from 3,600 to 11,600 ng/g, were from poor-quality maize collected in the Kisii district. Many samples with a high incidence of visibly diseased kernels contained little or no fumonisin B₁, despite the presence of F. moniliforme. This result may be attributable to the inability of F. moniliforme isolates present in Kenyan maize to produce fumonisins, to the presence of other ear rot fungi, and/or to environmental conditions unfavorable for fumonisin production.     

Effects of beauvericin to mammalian tissue and its production by Austrian isolates ofFusarium proliferatum and Fusarium subglutinans

Austrian isolates ofFusarium subglutinans andFusarium proliferatum were studied for their ability to produce beauvericin, moniliformin and fumonisin B₁ and B₂ under laboratory conditions. Analytical methodology for beauvericin was specially adapted for this task. Our analyses showed that the strains produced beauvericin up to 687 mg /kg maize and moniliformin up to 70 mg/kg. The culture ofF. proliferatum in addition produced fumonisin B₁ and B₂ at levels of 106 and 61 mg/kg,respectively. The preliminary toxicity experiments performed in this study clearly indicated a toxic effect of beauvericin on the contractility of mammalian smooth muscle and thus on mammalian cells.     

Pathogenicity of Alternaria alternata and Fusarium moniliforme and Phytotoxicity of AAL-toxin and Fumonisin B1 on Tomato Cultivars

Phytotoxicity of AAL-toxin and fumonisin B₁ to six cultivars of tomato was compared with the pathogenicity of their fungal sources, Alternaria alternata and Fusarium moniliforme, respectively. These include two AAL-toxin susceptible cultivars with genotypes(asc/asc), three resistant cultivars (Asc/Asc), and a heterozygous cultivar (Asc/asc.) A. alternata spores were pathogenic to the susceptible but not to the resistant cultivars F. moniliforme was not pathogenic to any of the tomatoes. Filtrates of both fungi grown on rice containing their respective toxins caused necrosis within 48 h and eventually mortality on susceptible cultivars but not on the resistant lines. The heterozygous cultivar Asc/asc showed minimal damage and no mortality after 14 days exposure to both filtrates and both toxins. The spores of both fungi had no effect on heterozygous intact plants. Tomato leaf disc bioassays with AAL-toxin and fumonisin B₁ at 1μM caused cellular leakage and reduced chlorophyll content in susceptible cultivars and minimal effects on the heterozygous and resistant varieties.     

Mycoflora and mycotoxins natural occurrence in corn from entre rios province, Argentina

Corn samples were collected in 1999 from three departments of Entre Réos province, Argentina, and were surveyed for mould contamination and natural occurrence ofFusarium mycotoxins, ochratoxin A and aflatoxins.Fusarium verticillioides was the most prevalent fungal species recorded at all departments. Zearalenone, deoxynivalenol and ochratoxin A were not found in any samples. Only one of the 52 corn samples analysed was contaminated with aflatoxin B₁ (17 μg/kg). Fumonisin B₁ was found in 58 % of samples (range of positive samples: 47– 3,347 μg/kg), fumonisin B₂ in 33.0 % (range of positive samples: 23–537 μg/kg) and fumonisin B₃ in 25.0 % (range of positive samples: 24–287 μg/kg) of them. This is the first report on the natural occurrence of mycotoxins in corn from Entre Ríos province, Argentina. Levels of fumonisins were lower than detected in other Argentinian provinces.     

Fungi,Aflatoxins, Fumonisin B<Subscript>l</Subscript> and Zearalenone Contaminating Sorghum-based Traditional Malt,Wort and Beer in Botswana

Brewing and consumption of traditional beer have social–economic significance in most African countries including Botswana. Traditional sorghum malt, wort, and beer samples were collected from three villages around Gaborone, Botswana. Forty-six malt samples were analyzed for fungi on three different media and developing colonies were subcultured for identification. Rhizopus, Fusarium, Mucor, and Aspergillus were the most common genera isolated. Out of the 46 malt samples, 72% contained Rhizopus stolonifer, 63% Fusarium verticillioides (syn. Fusarium moniliforme), and 37% Aspergillus flavus. Although Aspergillus flavus was isolated from malt samples, aflatoxins (B₁, B₂, G₁, and G₂) were not detected in any of the samples analyzed. When the malt, wort, and beer samples were analyzed for fumonisin B_l and zearalenone, fumonisin B₁ was detected in 3 malt samples, with concentrations ranging from 47 to 1316 μg/kg, while zearalenone was detected in 56%, 48% and 48% of the malt, wort and beer samples, respectively. Zearalenone concentration in samples ranged from 102 to 2213 μg/kg in malt, 26 to 285 μg/l in wort and 20 to 201 μg/l, in beer. Zearalenone carry-over from wort to beer ranged from 23 to 403%. Therefore, although aflatoxins and fumonisin B₁ do not appear to be major contaminants, zearalenone is common and could pose a potential problem in traditional beer in Botswana.     

Fumonisin B1 production and vegetative compatibility of strains from Gibberella fujikuroi mating population “A” (Fusarium moniliforme)

We examined 25 strains of Fusarium moniliforme from eight states known to be associated with equine leukoencephalomalacia, a disease caused by the mycotoxin fumonisin B₁. We determined the mating population, mating type, and vegetative compatibility group to which each of these strains belonged. All 25 strains were in the A mating population; 12 were A⁺ and 13 were A^–. Seventeen of the 25 strains were female fertile; these strains also averaged higher levels of fumonisin B₁ production than did the strains that were female sterile. Nitrate non-utilizing (nit) mutants were generated in all 25 strains and each strain was assigned to a unique vegetative compatibility group based on the inability of the derived nit mutants to form a prototrophic heterokaryon with complementary nit mutants derived from any of the other strains examined. From these data, we concluded that the production of fumonisin B₁ is a general characteristic of strains from the A mating population of Gibberella fujikuroi associated with equine leukoencephalomalacia, since all 25 of the isolates that we examined were genetically distinct individuals.