Formation of moniliformin by Fusarium sporotrichioides and Fusarium culmorum

Two strains of Fusarium sporotrichioides and one strain of F. culmorum were shown to produce the mycotoxin moniliformin in rice culture. Identification was by reverse-phase liquid chromatography, thin-layer chromatography, and mass spectrometry.     

Screeing of toxic isolates of Fusarium poae and Fusarium sporotrichiodes involved in causing alimentary toxic aleukia.

A total of 131 isolates of Fusarium poae and F. sporotrichioides from overwintered cereals, which were associated with the alimentary toxic aleukia toxicoses in the Soviet Union, were tested for their ability to produce T-2 toxin [4 beta, 15 diacetoxy-8alpha-(3-methylbutyryloxy)-12,13-epoxytrichothec-9-en 3alpha-ol]. The presence of T-2 toxin was determined by thin-layer chromatography, gas-liquid chromatography, spectroscopic analyses, and the rabbit skin test. A good correlation was demonstrated between T-2 toxin dectetion by thin-layer chromatography and inflammatory skin reactions of rabbits.     

Analysis of deoxynivalenol from cultures of Fusarium species

Eight isolates of Fusarium roseum and three of Fusarium colmorum were found to produce deoxynivalenol in rice cultures. Deoxynivalenol was extracted with aqueous methanol (40%) and purified by partitioning with ethyl acetate and acetonitrile-petroleum ether (boiling point, 60--70 degrees C). The toxin was identified by gas chromatography/mass spectrometry and quantified by gas-liquid chromatography. High recoveries (80%) of deoxynivalenol were obtained from rice cultures, and as low as 0.250 microgram of the toxin per g was detected.     

Production of fumonisins by Fusarium moniliforme and Fusarium proliferatum isolates associated with equine leukoencephalomalacia and a pulmonary edema syndrome in swine

Fumonisin B1 (FB1) and FB2 were isolated from corn cultures of both Fusarium moniliforme and Fusarium proliferatum. Respective concentrations in culture materials of FB1 and FB2 ranged from 960 to 2,350 and 120 to 320 micrograms/g for F. moniliforme and from 1,670 to 2,790 and 150 to 320 micrograms/g for F. proliferatum. Thin-layer chromatography, gas chromatography-mass spectroscopy, high-performance liquid chromatography, and liquid secondary ion mass spectroscopy were used for detection. Fumonisins from F. proliferatum have not previously been reported.     

Analysis of deoxynivalenol from cultures of Fusarium species.

Eight isolates of Fusarium roseum and three of Fusarium colmorum were found to produce deoxynivalenol in rice cultures. Deoxynivalenol was extracted with aqueous methanol (40%) and purified by partitioning with ethyl acetate and acetonitrile-petroleum ether (boiling point, 60--70 degrees C). The toxin was identified by gas chromatography/mass spectrometry and quantified by gas-liquid chromatography. High recoveries (80%) of deoxynivalenol were obtained from rice cultures, and as low as 0.250 microgram of the toxin per g was detected.     

Production of fumonisins by Fusarium moniliforme and Fusarium proliferatum isolates associated with equine leukoencephalomalacia and a pulmonary edema syndrome in swine.

Fumonisin B1 (FB1) and FB2 were isolated from corn cultures of both Fusarium moniliforme and Fusarium proliferatum. Respective concentrations in culture materials of FB1 and FB2 ranged from 960 to 2,350 and 120 to 320 micrograms/g for F. moniliforme and from 1,670 to 2,790 and 150 to 320 micrograms/g for F. proliferatum. Thin-layer chromatography, gas chromatography-mass spectroscopy, high-performance liquid chromatography, and liquid secondary ion mass spectroscopy were used for detection. Fumonisins from F. proliferatum have not previously been reported.     

Estrogenic Metabolite Produced by Fusarium graminearum in Stored Corn

A derivative of resorcinylic acid, produced by the fungus Fusarium graminearum, has been found to be responsible for the estrogenic signs in swine and laboratory rats. An estrogenic response in rats can be incited by injecting intramuscularly as little as 20 mug of the estrogen (F-2). Stimulation in growth of rats was noted at the lower concentrations (20 to 40 mug) of a series. Up to 3,500 ppm of the estrogen was produced on a solid corn medium. The compound is relatively stable to heat and ultraviolet irradiation. Methods of analysis have been developed and include: extraction procedures, evaluations by ultraviolet absorption spectrophotometry, thin-layer chromatography, and gas-liquid chromatography.     

Mycotoxin formation by different geographic isolates of Fusarium crookwellense

Eighteen Fusarium crookwellense isolates from the continents of Australia, Europe, and North America were compared for their ability to produce mycotoxins on corn at 25 °C after 2 weeks. Extracts from corn fermented with each Fusarium isolate were analyzed by thin-layer chromatography (TLC) and gas chromatography/mass spectroscopy (GS/MS) for mycotoxins. Toxins detected were zearalenone (13 isolates), fusarin C (11 isolates), nivalenol (4 isolates), and diacetoxyscirpenol (2 isolates). Zearalenone and fusarin C were produced by isolates from each continent, while nivalenol was detected in the Fusarium isolates originating from Australia and one isolate from the United States.The mention of firm names or trade products does not imply that they are endorsed or recommended by the U.S. Department of Agriculture over other firms or similar products not mentioned     

Correlation of Biological to Chromatographic Data for Two Mycotoxins Elaborated by Fusarium

Thirty-seven identified strains of Fusarium, most of them isolated from fescue grass, were tested for their ability to elaborate mycotoxins in laboratory culture. The presence of the toxins was determined by infrared light, thin-layer chromatography, mouse toxicity, fungistatic effects, and phytotoxic properties. A good correlation was demonstrated between T-2 toxin detection by thin-layer chromatography and inhibition of Rhodotorula rubra by culture extracts. All of the strains producing either butenolide or T-2 toxin were toxic to mice with but one exception; those producing T-2 toxin inhibited growth of the yeast.     

Purification by affinity chromatography and physicochemical properties of the guanine-specific ribonuclease of Fusarium moniliforme

Ribonuclease F1, the guanine-specific ribonuclease of Fusarium moniliforme, was purified to homogeneity by a combination of ethanol fractionation, affinity chromatography and DEAE-cellulose column chromatography. The adsorbent for the affinity chromatography was synthesized by the coupling of periodate-oxidized guanosine 5'-monophosphate to aminohexyl agarose followed by sodium borohydride reduction. Ribonuclease F2, the minor component, was also purified to near homogeneity by the same procedure. Ribonucleases F1 and F2 had the same molecular weight (about 11,000) as determined by gel filtration and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. They also showed the same amino acid composition and differed only in the isoelectric point: 4.10 for F1 and 3.96 for F2.     

Mycotoxin Production by Fusarium Species Isolated from Bananas

The ability of Fusarium species isolated from bananas to produce mycotoxins was studied with 66 isolates of the following species: F. semitectum var. majus (8 isolates), F. camptoceras (3 isolates), a Fusarium sp. (3 isolates), F. moniliforme (16 isolates), F. proliferatum (9 isolates), F. subglutinans (3 isolates), F. solani (3 isolates), F. oxysporum (5 isolates), F. graminearum (7 isolates), F. dimerum (3 isolates), F. acuminatum (3 isolates), and F. equiseti (3 isolates). All isolates were cultured on autoclaved corn grains. Their toxicity to Artemia salina L. larvae was examined. Some of the toxic effects observed arose from the production of known mycotoxins that were determined by thin-layer chromatography, gas chromatography, or high-performance liquid chromatography. All F. camptoceras and Fusarium sp. isolates proved toxic to A. salina larvae; however, no specific toxic metabolites could be identified. This was also the case with eight isolates of F. moniliforme and three of F. proliferatum. The following mycotoxins were encountered in the corn culture extracts: fumonisin B(inf1) (40 to 2,900 (mu)g/g), fumonisin B(inf2) (150 to 320 (mu)g/g), moniliformin (10 to 1,670 (mu)g/g), zearalenone (5 to 470 (mu)g/g), (alpha)-zearalenol (5 to 10 (mu)g/g), deoxynivalenol (8 to 35 (mu)g/g), 3-acetyldeoxynivalenol (5 to 10 (mu)g/g), neosolaniol (50 to 180 (mu)g/g), and T-2 tetraol (5 to 15 (mu)g/g). Based on the results, additional compounds produced by the fungal isolates may play prominent roles in the toxic effects on larvae observed. This is the first reported study on the mycotoxin-producing abilities of Fusarium species that contaminate bananas.     

Purification and properties of an extracellular beta-xylosidase from a newly isolated Fusarium proliferatum

An extracellular beta-xylosidase from a newly isolated Fusarium proliferatum (NRRL 26517) capable of utilizing corn fiber xylan as growth substrate was purified to homogeneity from the culture supernatant by DEAE-Sepharose CL-6B batch adsorption chromatography, CM Bio-Gel A column chromatography, Bio-Gel A-0.5 m gel filtration and Bio-Gel HTP Hydroxyapatite column chromatography. The purified beta-xylosidase (specific activity, 53 U/mg protein) had a molecular weight of 91,200 as estimated by SDS-PAGE. The optimum temperature and pH for the action of the enzyme were 60 degrees C and 4.5, respectively. The purified enzyme hydrolyzed xylobiose and higher xylooligosaccharides but was inactive against xylan substrates. It had a Km value of 0.77 mM (p-nitrophenol-beta-D-xyloside, pH 4.5, 50 degrees C) and was competitively inhibited by xylose with a Ki value of 5 mM. The enzyme did not require any metal ion for activity and stability. Comparative properties of this enzyme with other fungal beta-xylosidases are presented.     

Purification and characterization of the sesquiterpene cyclase trichodiene synthetase from Fusarium sporotrichioides

The sesquiterpene cyclase, trichodiene synthetase, has been purified from a supernatant fraction of Fusarium sporotrichioides by hydrophobic interaction, anion exchange, and gel filtration chromatography. Purified enzyme had a specific activity 15-fold higher than that previously reported for preparations of terpene cyclases. Molecular weight determinations by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration chromatography indicated the enzyme to be a dimer with a subunit of Mr 45,000. The requirement of Mg2+ (Km 0.1 mM) for activity could be partially substituted with Mn2+ at a concentration of 0.01 mM, but higher concentrations of Mn2+ were inhibitory. Maximum activity was observed between pH 6.75 and pH 7.75. The Km for farnesyl pyrophosphate was 0.065 microM.     

Linamarase from Fusarium equiseti

Summary Linamarase from Fusarium equiseti was purified 56-fold by ammonium sulphate fractionation, gel filtration on sephadex G-150 and ion-exchange chromatography on DEAE-sephadex A-50-120. The enzyme has Kms of 0.36 mM and 0.51 mM with respect to the artifical substrate, p-nitrophenyl--d-glucoside and its natural substrate, linamarin, respectively. -Gluconolactone is a strong competitive inhibitor of the enzyme with Ki of 0.2 mM when p-nitrophenyl--d-glucoside is the substrate. The pH optimum of the enzyme is 6.0 and further analysis indicates that the carboxyl of aspartate or glutamate, imidazole of histidine and the sulphhydryl group of cysteine may be involved in enzyme catalysis. The F. equiseti linamarase is significantly inhibited by such thiol-group reagents as iodoacetate, p-hydroxymercuribenzoate and iodosobenzoate indicating that sulphhydryl group may be present at the active site of the enzyme. The enzyme is stable up to 45°C which corresponds approximately with the optimum temperature of the linamarase-catalysed hydrolysis whose Ea was found to be 8.21 kcal/mole.     

The cellulase of Fusarium solani. Resolution of the enzyme complex

1. Culture filtrates from Fusarium solani were fractionated by ion-exchange chromatography on DEAE-Sephadex, followed by gel chromatography on Sephadex G-100, into a C(1) component, a C(x) component (CM-cellulase) and a beta-glucosidase (cellobiase) component. 2. The individual components showed little capacity for the solubilization of cotton fibre (cellulase activity), but when recombined in their original proportions 81% of the original cellulase activity was recovered. 3. The C(1) components of F. solani and Trichoderma koningii were similar in their pH optima, heat stabilities over the pH range 5-8 and elution volumes on Sephadex G-100. 4. The C(1) component of F. solani synergized with the C(x) component of T. koningii and conversely. 5. The C(1) and the beta-glucosidase components of F. solani were devoid of the swelling-factor (S-factor) activity associated with the C(x) component.     

Preferential binding of radiolabeled zearalenone to a protein fraction of Fusarium roseum graminearum.

Zearalenone [6-(10-hydroxy-6-oxo-trans-1-undecenyl)beta-resorcyclic acid lactone] is a hormone produced by Fusarium spp. which regulates the sexual stage in F. roseum. 3H- and 14C-labeled zearalenone were found to bind preferentially to one of two peaks containing uncharacterized proteins obtained from the cytosol of young mycelium and resolved by gel column chromatography. The proteins were partially purified by successive resolution on Sephadex G-100, Sephadex G-200, and BioGel P-300. Free zearalenone (37%) was reisolated from the purified proteins after resolution by thin-layer chromatography or partitioning with ethyl acetate.     

Simple method for isolation of 4-deoxynivalenol from rice inoculated with Fusarium graminearum.

A new method for preparative isolation of 4-deoxynivalenol (DON) is presented. This method avoids the loss of material during purification on silica gel by column chromatography. DON and 3-acetyldeoxynivalenol in crude extracts of rice inoculated with Fusarium graminearum were converted to triacetyldeoxynivalenol; the acetylated product was easier to purify by silica gel chromatography than DON is. After hydrolysis and further purification on a charcoal-alumina column, the 71% pure DON was recovered in yields as high as 450 mg of DON per kg of rice. Subsequent separation on a Sephadex LH20 column yielded DON that was greater than 90% pure.     

Preparation of 4,15-diacetoxyscirpenol from cultures of Fusarium sambucinum NRRL 13495

Filtrates of Fusarium sambucinum NRRL 13495 grown in a stagnant culture for 9 days contained up to 458 +/- 60 (mean +/- standard error; n = 3) mg of 4,15-diacetoxyscirpenol per liter depending on culture conditions. Extraction with ethyl acetate, chromatography on a column of silica gel, and crystallization from mixtures of ethyl acetate and hexane provided pure material in 96% yield.     

Analysis of Fusarium toxins in maize and wheat using thin layer chromatography

Thin layer chromatography (TLC) methods for identifying and quantifying deoxynivalenol (DON), fumonisin B1 (FB1) and zearalenone in grain samples were compared to immunoassay (ELISA) and high performance liquid chromatography (HPLC) methods to determine the reliability of the less expensive TLC. There was a very good agreement between levels of DON measured by TLC and competitive-direct ELISA, and between levels of fumonisin B1 measured by TLC and HPLC, over a wide range of concentrations. Correlation coefficients (Pearson's) were 0.978, 0.914 and 0.953 for DON in maize, DON in wheat and FB1 in maize respectively. A lower correlation coefficient (r = 0.672) was obtained when zearalenone was quantified by TLC and HPLC. Possible reasons for this are discussed. A cost comparison of the various methods revealed that TLC was the least expensive for sample analysis. It is recommended that researchers choose which analytical method to use based upon individual considerations of cost and precision. This revised version was published online in June 2006 with corrections to the Cover Date.     

海洋真菌Fusarium sp.次级代谢产物的研究

采用硅胶柱色谱、Sephadex LH-20凝胶柱色谱、开放ODS柱色谱以及HPLC等方法从海洋真菌Fusarium sp.的菌丝体中分离得到5个化合物,通过波谱数据及理化性质分别鉴定为3β,15β-二羟基-(22E,24R)-麦角甾-5,8(14),22-三烯-7-酮(1)、3β,5α,9α-三羟基-(22E,24R)-麦角甾-7,22-二烯-6-酮(2)、(22E,24R)-麦角甾-7,22-二烯-3β,5α,6β-三醇(3)、5α,8α-过氧-(22E,24R)-麦角甾-6,22-二烯-3β-醇(4)和丁二酸(5).其中化合物1和2首次从该属真菌中分离得到.