Natural occurrence of fumonisins in corn puff in Argentina

Maize presents a substantial contamination by fumonisins (FB) throughout the world. In particular, Argentina presents a high frequency of positive samples and levels of up to 10,000 μg/kg of total FB, depending on the harvest campaign studied. Corn puff, an extruded product of high consumption among children and adolescent populations, was analyzed with the aim of determining the presence and levels of fumonisins B₁, B₂ and B₃. In the present study, 20 samples of different brands were collected from commercial stores. Two solvent systems, two types of agitation, and the number of extractions were tested in order to find the most suitable method to establish the level of fumonisins in corn puff. Extracts were analyzed by high performance liquid chromatography (HPLC) with fluorescence detection. A C18 column and precolumn derivatization with orthophtalaldialdehyde were utilized. The average of fumonisins found in 20 samples was 257.5 μg/kg (n?=?19), 70.4 μg/kg (n??=?14) and 73.3 μg/kg (n??=?6) for FB₁, FB₂ and FB₃, on positive samples, respectively. These are the first analyses in Argentina of this type of product, highlighting the need to continue the studies in the processing industries because, despite the extrusion process that the raw material suffers, a sample was found with a contamination of 1,649 μg/kg total fumonisins.     

Trends of fumonisin contamination and animal intoxication through monitoring 1991 to 1997 corn crop in the State of Paraná, Brazil

Eleven feed samples associated with six animal (horse and poultry) intoxication outbreaks (1991) in the state of Paraná, Brazil, were evaluated for fungal and fumonisin contamination. In order to estimate the␣trend of livestock intoxication, fumonisin contamination was monitored in corn produced both at the commercial level (1991, 1995 crop), and in an experimental field at a local Agronomy Institute (1997 crop). The total mould count in the feed samples ranged from 2.9 × 10³ to 1.9 × 10⁷ CFU/g, with Fusarium verticillioides as the predominant species, at a high count of 2.4 × 10⁴–6.5 × 10⁵ CFU/g. Fumonisins (FB₁ + FB₂) were detected in all corn-based feed samples at levels ranging from 2.89 to 14.54 μg/g. All 27 Northern corn samples (1991 crop) were contaminated with fumonisins at levels ranging from 2.32 to 16.64 μg/g. Twenty-six (96.3%) out of 27 corn samples from the Central-Southern region (1995 crop) were positive for fumonisins (FB₁+FB₂), with the range of 0.07–3.66 μg/g, while all 37 Northern samples (1995 crop) were contaminated with fumonisins ranging from 0.57 to 9.97 μg/g. Twenty-one out of 37 corn samples from the Northern region (1997 crop) were positive for fumonisins, but at low level (range of 0.05–2.67 μg/g). The results showed a decreasing trend in fumonisin contamination over the years. Nowadays animal intoxication outbreaks rarely occur in this State, as both animal producers and feed industries have become conscious about monitoring of corn and other raw materials at the quality control level.     

Occurrence of Fusarium Mycotoxin Fumonisin B1 and B2 in Animal Feeds in Korea

The objective of this study was to monitor the occurrence and levels of fumonisin B₁ (FB₁) and fumonisin B₂ (FB₂) in animal feeds distributed in South Korea in 2011. The contamination levels of FB₁ and FB₂ were investigated in 150 samples of compound feeds and in 40 samples of feed ingredients. The contamination rate of feed ingredients with FB₁ and FB₂ was 50 and 40 %, respectively. FB₂ was only found in samples contaminated with FB₁. Of the compound feeds, 85 % were contaminated by FB₁ and 47 % were contaminated by FB₂. The highest contamination rate of FBs was observed in compound feeds for cattle (FB₁: 100 %; FB₂: 80 %), followed by poultry feed (FB₁: 78 %; FB₂: 40 %) and swine feed (FB₁: 76 %; FB₂: 22 %). The highest contamination level (14,600 ng/g) for FB₁ were found in poultry broiler feed (early feeding period) samples, which had 82 % contamination rate (9/11), and the highest level of FB₂ (2,280 ng/g) was found in feed for fatting calves,which had a contamination rate of 100 %.     

Determination of mycobiota and mycotoxins in pig feed in central Argentina

Aims: To evaluate the mycobiota and natural levels of aflatoxins, fumonisins and zearalenone present in compound feed and home‐corn grains intended for fattening pigs. Methods and Results: Total fungi, Fusarium and Aspergillus species occurrence were examined. Aflatoxins and zearalenone were detected by thin‐layer chromatography and fumonisins by high‐pressure liquid chromatography. Fungal counts were generally higher than 1 × 10⁵ colony forming units (CFU) ml^?1. Aspergillus flavus, Aspergillus parasiticus and Fusarium verticillioides were the most prevalent species. FB₁ and FB₂ were detected in all feed and corn samples. Aflatoxin B₁ was detected in 33·33% of initial and growing feed and in 44·44% of final feed samples. It was not detected in corn samples. All feed and corn samples were negative for AFB₂, AFG₁, AFG₂ and ZEA presence during all growing stages tested. Conclusions: Fungal counts at all growing periods exceeded the levels proposed as feed hygienic quality limits. Aflatoxin levels in all feeds and fumonisin levels in many samples were higher than the established regulations. Significance and Impact of the Study: The presence of mycotoxins indicates the existence of contamination. This fact requires periodic monitoring to prevent the occurrence of mycotoxicosis in animal production, to reduce the economic losses and to minimize hazards to human health.     

Production of fumonisins B1, B2 and B3 byFusarium proliferatum Isolated from rye grains

Using the seed- plate technique, we have isolated a strain ofF. proliferatum from rye grains that produces 3 fumonisins, fumonisin B₁ (FB₁), FB₂ and FB₃ on inoculated rice and corn. Inoculated corn and rice were extracted with an aqueous methanol solution and fumonisin concentrations estimated using high performance liquid chromatography. Production of all 3 fumonisins (FB₁, FB₂ and FB₃) was much higher on rice than corn; ranging from 3816, 1068 and 985 ppm to 1643, 350 and 162 ppm respectively. We conclude that all natural substrates whereF. proliferatum is present as a component of the mycoflora should be monitored for the presence of fumonisins.     

Production of fumonisin B1 and B2 byFusarium moniliforme isolated from Korean corn kerneis for feed

The natural occurrence of fumonisin B₁ (FB₁) and B₂ (FB₂), a promoter for hepatocarcinogenesis, was investigated in Korean corn kernels for feed by HPLC with fluorescence detection. From the 12 corn kernel samples, FB₁ was detected in 5 samples at levels ranging from 53 to 1327ng/g, while FB₂ was found in 4 samples from 69 to 680ng/g. In the positive samples, the average concentrations of FB₁ and FB₂ were 506 and 288ng/g, respectively. One sample (No. K3) showed the highest FB₁ and FB₂ contents as 1327 and 680ng/g, respectively. In the micrological survey on 5 positive samples for FB₁ and FB₂, 6 strains ofFusarium monlliforme were isolated, and all these isolates had a producibility of FB₁ and FB₁, with maximum levels of 80.7 to 180.9 g/g.Thisis the first report on the natural co-contamination of FB₁ and FB₂ in Korean corn kernels for feed, and on the ability ofF. moniliforme isolated from corn kernels for feed in Korea to produce FB₁ and FB₂.     

Natural occurrence of fumonisins and their correlation to Fusarium contamination in commercial corn hybrids growth in Argentina

Fifty commercial corn hybrids with different endosperm characteristics, vegetative cycle length and cross class grown in the same geographical area (Cordoba Province, Argentina) were analysed for fumonisin accumulation. All hybrids analysed showed fumonisin B₁ and B₂ contamination ranging from 185 to 27,050 ng/g for FB₁ and from 40 to 9950 ng/g for FB₂. Although most of the hybrids analysed had flint-type endosperm, two hybrids with dent-type endosperm (e.g. Prozea 10 and AX 746) showed the highest level of fumonisin (37,000 ng/g) and more FB₂ than FB₁ (FB₂/FB₁ ratio 2.42), respectively. There was no correlation between fumonisin concentration and length of the vegetative cycle. Among 18 hybrids examined for Fusarium species contamination there was also no correlation between fumonisin contamination and the level of infection with Fusarium species (Section Liseola). Eighteen hybrids showed fumonisin levels lower than 1000 ng/g. This result suggests that there is some possibility of selecting hybrids resistant or less susceptible to fumonisin and Fusarium contamination.     

Occurrence of fumonisins in asparagus (asparagus officinalis L.) and garlic (allium sativum L.) from Germany

Fusarium proliferatum is able to produce fumonisins and is considered a pathogen of many economically important plants (e.g. corn, rice, asparagus) [1]. The occurrence of fumonisin FB₁ inF. proliferatum infected asparagus spears from Germany was investigated using a liquid chromatography/electrospray ionization-mass spectrometry (LC-ESI-MS) method with isotopically labeled fumonisin FB₁-d₆ as internal standard. Asparagus samples were harvested in July 2000 and screened forFusarium species. AltogetherF. oxysporum, F. proliferatum and F. sambucinum were isolated from the spears. The samples infected with F.proliferatum were subsequently analyzed for fumonisins. FB₁ was detected in 9 of the 10 samples in amounts ranging from 36.4 ng/g to 4513.7 ng/g (based on dry weight). Fumonisins FB₂ and FB₃ were found in six samples in lower concentrations. In asparagus spears of June 2002 we could findF. proliferatum in 6% of the samples, however no fumonisins were detectable. Furthermore the capability of producing FB₁ by the fungus in garlic bulbs was investigated. Therefore garlic was cultured inF. proliferatum contaminated soil and the bulbs were screened for infection with F.proliferatum and for the occurrence of fumonisins by LC-MS. F.proliferatum was detectable in the garlic tissue and all samples contained FB₁ (26.0 ng/g to 94.6 ng/g). This is the first report of the natural occurrence of FB₁ in German asparagus spears and furthermore our findings suggest a potential for natural contamination of garlic bulbs with fumonisins. For detailed results and methods see Ref. [2].     

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     

Occurrence of fumonisin B1 and B2 in corn-based foodstuffs in Taiwan market

Corn-based human foodstuffs purchased in Taiwan were analyzed for fumonisin B₁ (FB₁) and fumonisin B₂ (FB₂) using high-performance liquid chromatography. Fifty-two (33.9%) and 32 (20.9%) of 153 samples were found to contain FB₁ (73–2395 ng/g) and FB2 (120–715 ng/g), respectively. The highest frequency of detection and also the highest FB1 concentrations were found in sweetcorn (50%, 1089 ng/g) and cornflour (50%, 608 ng/g), followed by corn snacks (33.3%, 2395 ng/g), miscellaneous corn products (33.3%, 73 ng/g), popcorn (31.8%, 1003 ng/g) and cornflakes (23.5%, 1281 ng/g). 16 corn snacks (= approximately 20.5% of the samples) had an average FB₁ and FB₂ content of 456 and 145 ng/g, respectively, while six sweetcorn (= 25%) samples were contaminated with an average of 400 ng/g of FB₁ and 65 ng/g of FB₂. Of the 22 pop-corn samples examined, 7 had an average of 347 ng/g and 116 ng/g of FB₁ and FB₂, respectively. During an analysis of the distribution pattern for the combined fumonisin levels of FB₁ and FB₂, it became apparent that more than 69% of tested samples had fumonisin concentrations below 100 ng/g, while 11.1% (or 17 samples) contained in excess of 600 ng toxins per g. These results clearly illustrated that commercially available corn-based foodstuffs for human consumption in Taiwan are frequently contaminated with FB₁ and FB₂.This revised version was published online in October 2005 with corrections to the Cover Date.     

Occurrence of fumonisins in maize imported into Iran during 2001–2002

Fumonisins, fungal toxins found primarily in maize and produced by various Fusarium species, have been shown to cause a variety of significant adverse health effects in livestock and experimental animals, and are probable human carcinogens. Thirty-three maize samples were collected at ports from bulk shipments, which were imported into Iran from six countries during 2001–2002, and analysed by HPLC for the most abundant of the naturally occurring fumonisin analogues, namely fumonisins B₁ (FB₁), B₂ (FB₂) and B₃ (FB₃). Of the 33 samples, 21 (64%) were found to contain FB₁ (58–512 μg/kg) at levels above 10 μg/kg. The frequency of FB₁ found in maize samples imported from Uruguay and Canada was 75%, followed by China and Argentina (67%), USA (60%), and Brazil (50%). The average FB₁ level was 266 and 169 μg/kg for positive and all samples, respectively. Medians were 250 and 146 μg/kg for positive and all samples, respectively. FB₂ levels ranged from not detected (<10 μg/kg) to 53 μg/kg, whereas no sample had an FB₃ level above the detection level (10 μg/kg). This is the first report of fumonisin contamination of imported maize in Iran. Although, the level of all detected fumonisins were below the Iranian and FDA tolerance levels for foods and feeds, It is necessary to maintain the strict rules to ensure continued safety of imported maize.     

Studies on extraction of fumonisins from rice, corn-based foods and beans

Different solvent mixtures were examined for extraction of fumonisins from various naturally contaminated and spiked foods and foodstuffs: rough rice, retail rice, rice flour, white corn flour, corn meal, corn starch, corn flakes, tortilla/corn chips, white bean flour, white beans, mung beans, adzuki beans and infant cereals. Most of the naturally contaminated samples were analyzed using the extraction solvent mixtures methanol-acetonitrile-water (25:25:50) (solvent A) and methanol-water (75:25 or 80:20) (solvents B, BB); some were extracted with 0.1 M sodium hydrogen phosphate-acetonitrile (1:1, adjusted to pH 3.0 with o-phosphoric acid) (solvent C) and methanol-0.025 M borate buffer (3:1, adjusted to pH 9.2 with 1 N sodium hydroxide) (solvent D). A 1-ml SAX solid phase extraction column was used for the cleanup in all cases except for infant cereals, for which immunoaffinity chromatography was used; fumonisin concentrations were determined by liquid chromatography. Solvent A gave slightly better extraction of fumonisins from one of two samples of naturally contaminated rough rice than solvent B (fumonisin B₁: 4080 ng/g versus 3150 ng/g; fumonisin B₂:1100 ng/ g versus 922 ng/g) and much better extraction than solvent C (1210 ng/g fumonisin B₁ and 315 ng/g fumonisin B₂) or solvent D (372 ng/ g fumonisin B1 and 191 ng/g fumonisin B2). However, spike recoveries on a similar rice naturally contaminated at a lower level were only in the 43–53% range (solvent A). Recovery of fumonisins was very poor from spiked white rice flour but satisfactory from other rice foods. Solvent A similarly gave slightly better extraction of fumonisins from a sample of naturally contaminated white corn flour than solvent B (fumonisin B₁ 1260 ng/g versus 931 ng/g; fumonisin B₂: 511 ng/g versus 447 ng/g ) and better extraction than solvents C and D. Solvent A was also a better solvent for extraction of fumonisins from naturally contaminated tortilla chips and infant cereals. Study of naturally contaminated corn starch was confounded by instability of fumonisins in this food. Recovery of fumonisins from spiked corn meal, tortilla chips, corn flakes, various types of beans and infant cereals with solvent A and/or solvent B (or BB) was satisfactory.     

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.     

Effect of<Emphasis Type="Italic">in vitro</Emphasis> digestion on fumonisin B<Subscript>1</Subscript> in corn flakes

Low levels of fumonisins have been found frequently in corn based breakfast cereals and can occur bound to protein and other matrix components.In vitro digestion of two samples of corn flakes was carried out under "fed conditions." Fumonisins were measured as o-phthaldialdehyde/mercaptoethanol derivatives by LC-fluorescence. One sample of corn flakes (FN12) had high concentrations of fumonisin B₁ (FB) (average 125 ng/g) and total bound FB₁, (TB FB₁) (average 92 ng/g) and the other (FN11) had a low level of free FB₁ (average 29 ng/g) and no detectable TB FB₁. After incubation of the samples with gastrointestinal tract solutions simulating saliva plus stomach and duodenal juices, chyme was analysed for FB₁, hydrolyzed FB₁ (HFB₁) and partially hydrolyzed fumonisin B₁ (PHFB₁). The bioaccessibility (percentage of FB₁ released from corn flakes into chyme) was 38-78% for incurred FB₁ in FN12, 8-54% for incurred plus spiked FB₁ in FN12, and 19-66% for incurred plus spiked FB₁ in FN11. HFB₁ and PHFB₁ were not detected. If free FB₁ was first extracted from sample FN12, no FB1 was detected in the chyme, indicating no contribution from TB FB₁. Concentrations were corrected for method recovery of FB₁ or, for bound FB₁, partial method recovery of HFB₁ Presented at the XIIth IUPAC International Symposium on Mycotoxins and Phycotoxins, Istanbul, Turkey, 21–25 May, 2007     

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.     

A survey of fumonisins (B1, B2, B3) in Indonesian corn-based food and feed samples

In this paper a survey is described for determination of contamination level of fumonisins (B¹, B², B³) in Indonesian cornbased feed and food samples. The survey was conducted from February to May 2001. Foodstuffs, which are consumed directly such as snacks and other products, were investigated for fumonisin contamination. Of 105 food and feed samples purchased from local retail stores and local poultry shops around Yogyakarta, Java, Indonesia were analyzed using ELISA. Results indicate that 74.3% of samples analyzed were contaminated in a large range of 10.0 – 3307 μg/kg, and the concentration of fumonisins depends on the type of samples. Detection limit of the method used was 9 μg/kg.From eight food samples of maize flour, and corn-based beverages and cereals, none was contaminated (below detection limit). For food samples of industrial products (19 samples), 13 were contaminated in the range of 22.8 – 105 μg/kg and 19 of 20 samples from home made products were contaminated between 12.9 – 234 μg/kg. The food samples contaminated in highest level occurred in corn. Of ten samples, 6 were contaminated from 68.0 – 2471 μg/kg. For feed samples, 17 corn samples were evaluated. Of those samples, 16 contained in a large range of 17.6 – 3306 μg/kg.     

Formation of fumonisin artefacts in thermal treated food

In order to study the formation of fumonisin artefacts and the binding of fumonisins to matrix components (e.g. starch and protein) in thermal treated food, model experiments were performed by heating fumonisin FB₁ with amino acid derivatives (protein model) and methyl-a-D-glucopyranoside (starch model). The reaction products were analysed by highperformance liquid chromatography-electrospray ionisationtandem mass spectrometry (HPLC-MS/MS). Using MS/MS experiments the formed reaction products were characterized as conjugates between fumonisin B₁ and the used substrates. The reaction product between fumonisin B₁ and methyl-α-D-glucopyranoside was purified and identified by nuclear magnetic resonance (NMR) spectroscopy as the diester of fumonisin B₁ and methyl-α-D-glucopyranoside. These studies indicate that fumonisins can bind to matrix components via their TCA side chains.     

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.     

Mutagenic potentials of fumonisin contaminated corn following ammonia decontamination procedure

Naturally contaminated corn implicated in an outbreak of equine leukoencephalomalacia (ELEM) in southeastern Arizona was analyzed for mutagenic potential using the Salmonella/microsome mutagenicity assay before and after treatment with the ammonia procedure. Crude acetonitrile: water (1+1) extracts of high-pressure/ambient temperature (HP/AT) ammonia decontaminated, HP/AT plus low pressure/high temperature (LP/HT), and non-ammoniated fumonisin contaminated corn were tested for mutagenic potentials. Relatively pure (approx. 90%) fumonisin B₁ standard was also tested for comparison purposes. The results of this experiment indicate that there was no mutagenic potential for the fumonisin B₁ standard at the concentrations tested (100 g/plate). Also, neither the naturally-contaminated corn nor the ammonia decontaminated samples elicited a positive mutagenic response. Fumonisin B₁ levels, as determined by HPLC methods, were reduced by an average of 79% via the ammonia decontamination process. It is encouraging to note that, while further work is necessary to increase the efficacy of the ammonia process to reduce fumonisin levels, the ammonia process did reduce fumonisin levels and no mutagenic potentials were apparent in the treated corn.Abbreviations HP/AT high pressure/ambient temperature - LP/HT low pressure/high temperature - ELEM equine leukoencephalomalacia - FB₁ fumonisin B₁ - FB₂ fumonisin B₂     

Production of a phage-displayed mouse ScFv antibody against fumonisin B1 and molecular docking analysis of their interactions

Fumonisins produced by Fusarium pathogens are mycotoxins present in maize and other grains in the field as well as during storage worldwide and pose a serious threat to humans and domestic animals. Fumonisin B consists of different chemotypes, and fumonisin B₁ (FB₁) is the most predominant fumonisin found in food/feed commodities. Recombinant antibody can be deployed to analyze the fumonisin toxicological mechanism and develop a simple and cost-effective method for the detection of fumonisins, which is vitally important for monitoring and preventing fumonisins from entering food/feed chains. In this study, FB₁ conjugated to keyhole limpet hemocyanin was used to immunize mice, from which RNA was isolated to construct a recombinant antibody library. Successive panning of the library by phage display was used to select monoclonal phage clones reactive to FB₁ conjugated to bovine serum albumin. Subsequent phage ELISA and sequencing analyses revealed four different reactive scFv antibodies specific to FB₁. Soluble expression and ELISA analysis showed that one scFv antibody, FBMA1, had the highest reactivity and could be purified from bacterial cells in large quantities. Surface plasmon resonance measurements further revealed that the FBMA1 scFv antibody had a binding kinetics of K _D = 1.89 × 10^–7 M. Molecular modeling and docking analyses suggested that the FBMA1 antibody shaped a proper cavity to embed the whole FB₁ molecule and that a steady-state complex was formed relying on intermolecular forces, including hydrogen bonding, electrostatic force and hydrophobic interactions. Thus, the scFv antibody can be applied for mechanistic studies of intermolecular interactions and fumonisin toxicity, and for the development of an immunoassay for fumonisin-contaminated food/feed samples.