Quantization of total fumonisins produced by Fusarium verticillioides strains in some maize and sorghum genotypes by ELISA (original) (raw)
Related papers
Toxins
Fumonisins are mycotoxins (MTs) produced mainly by the fungus Fusarium verticillioides, the main pathogens of maize which cause ear rot. The aim of this work was to evaluate some factors that may lead to high fumonisin production by F. verticillioides in maize grains, correlating the pathogen inoculation method with different genotypes grown in four Brazilian states. Experiments were conducted in 2015–2016 in maize crops from experimental maize fields located in four distinct states of Brazil. Results showed that contamination by fumonisin mycotoxins occurred even on symptomatic or asymptomatic grains. In all municipalities, the samples showed levels of fumonisin B1 that were higher than would be tolerable for the human consumption of corn products (the current tolerance limit for fumonisin is 1.5 μg g−1). High severity of grains infected with F. verticillioides does not always show high concentrations of fumonisins. Environments with higher temperatures may influence the production...
Journal of the Science of Food and Agriculture, 2012
BACKGROUND: Fusarium species are common fungal contaminants of maize and a number of them can produce mycotoxin fumonisins. China is one of the largest maize producers in the world. This study investigated the contamination of maize samples from three areas in eastern China by Fusarium and fumonisin-producing fungi as well as their fumonisin-producing potential. RESULTS: A total of 22 Fusarium strains were isolated, 19 of which were able to produce fumonisin. Among the 19 strains, 16 belonged to F. verticillioides, two to F. subglutinans and one to F. proliferatum. The majority (17/19) of the fumonisin-forming strains were high FB 1 producers, which is a potential health risk for the population in these areas. Fusarium contamination in samples from the mideastern area was the most serious (11 Fusarium strains, with nine producing fumonisin, isolated from 24 samples), followed by the northeastern area (nine Fusarium strains, with all nine producing fumonisin, isolated from 21 samples) and the southeastern area (two Fusarium strains, with one producing fumonisin, isolated from 19 samples). CONCLUSION: Although the overall levels of FBs and contamination by fumonisin-producing fungi in corn samples were not serious, the contaminating Fusarium strains possessed fairly strong toxicogenic ability and potential risk for food safety.
Infection of maize by Fusarium species and contamination with fumonisin in Africa
2004
Fusarium is one of the major fungal genera associated with maize in Africa. This genus comprises several toxigenic species including F. verticillioides and F. proliferatum, which are the most prolific producers of fumonisins. The fumonisins are a group of economically important mycotoxins and very common contaminants of maize-based foods and feeds throughout the world. They have been found to be associated with several animal diseases such as leukoencephalomalacia in horses and pulmonary oedema in pigs. Effects of fumonisins on humans are not yet well understood. However, their occurrence in maize has been associated with high incidences of oesophageal and liver cancer. Infection of maize by Fusarium species and contamination with fumonisins are generally influenced by many factors including environmental conditions (climate, temperature, humidity), insect infestation and pre-and postharvest handling. Attempts to control F. verticillioides and to detoxify or reduce fumonisin levels in maize have been undertaken. However, more research studies are urgently needed in order to understand more about this toxin. Fumonisins are less documented because they are recently discovered mycotoxins compared to aflatoxins. To date in Africa, apart from South Africa, very little information is available on Fusarium infection and fumonisin contamination in maize. It is a matter of great concern that on this continent, millions of people are consuming contaminated maize and maize-based foods daily without being aware of the danger.
Journal of food protection, 2007
Sixty samples of corn from both conventional and organic farms were tested for internal fungal contamination. Molds were identified to genus, and those belonging to the genus Fusarium were identified to species. Twenty isolates of Fusarium verticillioides were tested with a high-performance liquid chromatography-naphthalene dicarboxaldehyde-fluorescence method for their ability to produce fumonisins B1 and B2. The internal fungal infection in organic maize (63.20%) was significantly higher than that in conventional maize (40.27%) (P < 0.05). However, the distribution of fungal genera indicated a significantly higher prevalence of Fusarium in conventional (34.93%) than in organic (18.15%) maize, making Fusarium the predominant fungus in conventional maize. This difference in mold distribution between organic and conventional maize was attributed to the difference in cultivation system. The dominant Fusarium species in both conventional and organic samples was F. verticillioides. T...
Journal of Agricultural and Food Chemistry, 2005
Fumonisins are mycotoxins (MTs) produced mainly by the fungus Fusarium verticillioides, the main pathogens of maize which cause ear rot. The aim of this work was to evaluate some factors that may lead to high fumonisin production by F. verticillioides in maize grains, correlating the pathogen inoculation method with different genotypes grown in four Brazilian states. Experiments were conducted in 2015-2016 in maize crops from experimental maize fields located in four distinct states of Brazil. Results showed that contamination by fumonisin mycotoxins occurred even on symptomatic or asymptomatic grains. In all municipalities, the samples showed levels of fumonisin B1 that were higher than would be tolerable for the human consumption of corn products (the current tolerance limit for fumonisin is 1.5 µg g −1). High severity of grains infected with F. verticillioides does not always show high concentrations of fumonisins. Environments with higher temperatures may influence the production of high concentrations of fumonisin in maize hybrids. Spray inoculation methods and inoculation at the center of spikes did not influence fumonisin concentrations. Results showed that the hybrids P3630H, P32R48 and P3250 presented higher disease severity, as well as higher mycotoxin levels in the studied locations with higher temperatures.
High Fumonisin Content in Maize: Search for Source of Infection and Biological Function
Two fumonisin-nonproducing strains of Fusarium verticillioides (fum 1-3 and fum 1-4) and their progenitors (FUM 1-1) were tested for aggressiveness toward different plant species including maize, sorghum, rice and beetroot seedlings grown under greenhouse conditions. None of the plants showed obvious disease symptoms following root inoculation. The quantity of species-specific fungal biomass was measured by real-time PCR. No significant (P = 0.05) differences in colonization of tissues were detected between each wild type and the relevant mutant. F. verticillioides was not detected in any of the non-inoculated control plants. The fungus could transfer from the roots to the first two internodes/leaves of maize, rice/beetroot, regardless of fumonisin production. The symptomless systemic transmission rate, however, was low for sorghum. This phenomenon could be explained by different host preferences of biological species of Gibberella fujikuroi. The results indicate that in our system, fumonisin production was not required as a virulence factor for F. verticillioides to colonize the maize, rice and beetroot tissues.
1987
Many species of Fusarium are commonly associated wi th cereal s, particularly maize, but in New Zeal and , little is known of their significance as mycotoxin producers. These studies have examined the prevalence of fusari a and other fungi in maize and maize fi elds and have investi gated the presence and sources of some major Fusarium toxi ns in maize. Fung i in maize , husk , litter and soi l from maize fi el ds and in grain at harvest and in storage were assayed. The distribution of fungi was found to be uneven wi thin maize, husk and litter substrates wi thin a fi eld but in soi l was more homogeneous. Sampl ing techn iques were therefore developed to ensure representat ive subsamples were obtained from each source. Simi larly isol ation proc edures were chosen to ensure adequate recovery of fungi. Di lution and direct pla tings were used to prov ide informat ion on total populations and on fungi actual ly invading ker nel s, wi th two media, PDA-D and peNB. The med ium used showed no signi ficant influence on either viable counts or kernel contamination rates nor on the number of different Fus ari um spp recovered on the two media, but PDA-D supported a greater overal l variety of fungi. The numbers of genera and of Fusari um spp recorded by direct plating were significantly higher than wi th di lution pl ating. The total popul ation and the number of different genera and of Fusarium spp were compared for the four "field" substrates. A total of 25 genera was i sol ated , most bei ng recovered from soi 1 and 1 i tter. Fus arium was present in al l samples. Acremonium, Cladosporium, Penici llium and Mucor occurred regularly. The four substrates gave up to ten different Fusari um spp, F. gr ami nearum , F. culmorum and F. acumi natum being the most frequent. Husk and litter samples gave the highest viable counts for both total fungi and Fusarium spp. Field sample s of maize kernel s showed 13 genera and ten Fusari um spp. At harvest time total genera increased to 17 but Fusarium spp remai ned constant. Wh ile the total genera remained constant at 17 in stored sampl es, the number of Fusarium spp dropped to three, only � i i chromatography 1.5.2.3. Gas chromatographic and assoc i ated techniques 1.5.2.4. Multi-mycotoxin assay 1.5.2.5. Biological detection methods vi i TABLE OF CONTENTS (continued) CHAPTER 2. MATERIALS AND METHODS 2.1. MYCOLOGI CAL TECHNIQUES 2.1.1. Principal Med ia 2.
World Journal of Microbiology and Biotechnology, 2010
Fumonisins are a group of fungal toxins, occurring worldwide in maize infected mainly by Fusarium verticillioides. This paper describes the level of fumonisins in maize seed samples and the ability of F. verticillioides strains isolated from maize seeds grown in India to produce fumonisins. Forty-three seed samples intended to be used for consumption were collected from different regions of Karnataka and Andhra Pradesh. The samples were subjected to the agar plate method for the detection of F. verticillioides. Identification of F. verticillioides was done based on morphological characters and further confirmed by polymerase chain reaction. The majority of the samples were infected by F. verticillioides and infection percentage in the individual samples ranged from 5 to 51%. Twenty-three out of 35 (65%) strains were positive for fumonisin production in high performance liquid chromatography (HPLC) and competitive directenzyme linked immuno sorbent assay (CD-ELISA). Fumonisin level in seed samples ranged from 200 to 1,722 lg/g using CD-ELISA. HPLC could differentiate FB1 and FB2 toxins; out of 35 strains, 14 (40%) showed both FB1 and FB2 production. These findings indicate that there may be a risk of human exposure to fumonisins through the consumption of F. verticillioides infected cornbased foods in India.
2008
A quantitative detection tool was developed to enable the monitoring of fumonisin-producing fungi in food and feed commodities. To this end, a quantitative PCR (TaqMan) was developed that targets a conserved region in the polyketide synthase gene fum1, which is involved in the biosynthesis of fumonisin. Hence, this method specifically detected isolates from the fumonisin-producing species Fusarium verticillioides, F. proliferatum, F. nygamai and F. globosum whereas isolates of the fumonisin non-producing species F. equiseti, F. graminearum, F. oxysporum, F. semitectum and F. subglutinans that commonly occur on maize were not detected. Moreover, a few fumonisin non-producing F. verticillioides isolates did not generate any fluorescent signals and were therefore not detected. The correlation between quantitative PCR and mycotoxin content was determined using field samples collected at homestead farms in South Africa. Among 40 samples from the Eastern Cape collected in 2005 a good correlation (R 2 =0.8303) was found between pg fungal DNA and fumonisin content. A similar correlation (R 2 =0.8658) was found among 126 samples collected from four provinces in South Africa in 2007. These observations indicate that samples containing ≥ 40 pg fungal DNA/mg sample are suspected of also exceeding the 1 mg/kg total fumonisin level and therefore do not comply with the European Commission limit for fumonisins B 1 +B 2 for maize intended for direct human consumption that applies from 1 October 2007. Combined with the very high maize intake, our results indicate that fumonisin levels in maize from South African homesteads regularly exceed the tolerable daily intake for fumonisins.
DETECTION OF FUSARIUM SPECIES THAT PRODUCE FUMONISIN B1 IN MAIZE KERNELS USING
Eighty eight Maize grains samples were collected between November 2013 and May 2014 from local markets and silo of Baghdad city. The aim of study was to identification of associated with maize kernels and their ability to produce FB1 by using traditional and molecular methods. The results revealed that eight (58.6 %) was predominant fungus followed b Alternaria predominant species among F. proliferatum only thirteen isolates belong to F. proliferatum. F. proliferatum