Ameliorative effects of Lactobacillus against Aflatoxin B1 / Efeitos benéficos do Lactobacillus contra a Aflatoxin B1

Abstract Lactobacilli are probiotics with Aflatoxin (AF) detoxification ability, found in fermented products, GIT of animals and environment. Purpose of this study was to investigate the ability of broiler isolates of Lactobacillus against Aflatoxin B1 (AFB1). For this purpose, 5 isolates of Lactobacillus from broiler gut were incubated with 100 ppb AFB1 in aqueous environment and effect of different parameters (cell fractions, time, temperature, pH) on detoxification was determined by HPLC. The ameliorative effect of Lactobacillus salivarius (LS) against AFB1 was studied in broiler. The results revealed that LS (CR. 4) showed the best results (in vitro) as compared to other isolates (L. salivarius (CR. 3, CR, 4), L. agilis (CE. 2.1, CE. 3.1) and L. crispatus (CE. 28). Cell debris of CR. 4 showed significantly higher detoxification (P<0.05). Maximum amount of AFB1 was detoxified at 30°C (97%), pH 4.0 (99%) and 6 h (99.97%). In vivo study showed that AFB1 decreased weight gain (1,269 ± 0.04 gm/ bird), feed consumed (2,161 ± 0.08 gm/ bird), serum total protein (2.42 ± 0.34 gm/ dl), serum albumin (0.5 ± 0.2 2 gm/dl) and antibody titer (4.2 ± 0.83). Liver function enzymes were found (alanine transaminase (ALT): 32 ± 10.7 U/L) and aspartate transaminase (AST): 314.8 ± 27 U/L) elevated in AFB1 fed broilers. Treatment with 1% LS not only decreased the toxic effects of AFB1 (group D) but also improved the overall health of broilers due to its probiotic effects (p<0.05) as compared to control negative (group A). The detoxification ability of LS was better than commercial binder (CB) (0.2% Protmyc). It was concluded that detoxification of AFB1 by Lactobacillus was strain, temperature, pH and time dependent. LS has detoxification ability against AFB1 in vivo.

Resumo Os lactobacilos são probióticos com capacidade de desintoxicação da Aflatoxina (AF), encontrados em produtos fermentados, TGI de animais e meio ambiente. O objetivo deste estudo foi investigar a capacidade de isolados de frango de corte de Lactobacillus contra a Aflatoxina B1 (AFB1). Para tanto, 5 isolados de Lactobacillus de intestino de frango foram incubados com 100 ppb AFB1 em meio aquoso, e o efeito de diferentes parâmetros (frações celulares, tempo, temperatura, pH) na desintoxicação foi determinado por CLAE. O efeito melhorador de Lactobacillus salivarius (LS) contra AFB1 foi estudado em frangos de corte. Os resultados revelaram que LS (CR. 4) apresentou os melhores resultados (in vitro) em comparação com outros isolados [L. salivarius (CR. 3, CR. 4), L. agilis (CE. 2.1, CE. 3.1) e L. crispatus (CE. 28)]. Detritos celulares de CR. 4 mostraram desintoxicação significativamente maior (P < 0.05). A quantidade máxima de AFB1 foi desintoxicada a 30 °C (97%), pH 4.0 (99%) e 6 h (99,97%). O estudo in vivo mostrou que AFB1 diminuiu o ganho de peso (1,269 ± 0.04 g / ave), alimento consumido (2,161 ± 0.08 g / ave), proteína total sérica (2.42 ± 0.34 g / dl), albumina sérica (0.5 ± 0.22 gm / dl) e título de anticorpo (4.2 ± 0.83). As enzimas da função hepática foram encontradas (alanina transaminase (ALT): 32 ± 10.7 U / L) e aspartato transaminase (AST): 314.8 ± 27 U / L) elevadas em AFB1 alimentados com frangos. O tratamento com 1% LS não só diminuiu os efeitos tóxicos de AFB1 (grupo D), mas também melhorou a saúde geral dos frangos devido aos seus efeitos probióticos (p < 0.05) em comparação com o controle negativo (grupo A). A capacidade de desintoxicação do LS foi melhor do que o aglutinante comercial (CB) (0.2% Protmyc). Concluiu-se que a desintoxicação de AFB1 por Lactobacillus foi dependente da cepa, temperatura, pH e tempo. LS tem capacidade de desintoxicação contra AFB1 in vivo.

Contamination status and exposure risk of mycotoxins in Coicis Semen / 中国中药杂志

By investigating the contamination status and predicting the exposure risk of mycotoxin in Coicis Semen, we aim to provide guidance for the safety supervision of Chinese medicinal materials and the formulation(revision) of mycotoxin limit standards. The content of 14 mycotoxins in the 100 Coicis Semen samples collected from five major markets of Chinese medicinal materials in China was determined by UPLC-MS/MS. The probability evaluation model based on Monte Carlo simulation method was established after Chi-square test and One-way ANOVA of the sample contamination data. Health risk assessment was performed on the basis of margin of exposure(MOE) and margin of safety(MOS). The results showed that zearalenone(ZEN), aflatoxin B_1(AFB_1), deoxynivalenol(DON), sterigmatocystin(ST), and aflatoxin B_2(AFB_2) in the Coicis Semen samples had the detection rates of 84%, 75%, 36%, 19%, and 18%, and the mean contamination levels of 117.42, 4.78, 61.16, 6.61, and 2.13 μg·kg~(-1), respectively. According to the limit standards in the Chinese Pharmacopoeia(2020 edition), AFB_1, AFs and ZEN exceeded the standards to certain extents, with the over-standard rates of 12.0%, 9.0%, and 6.0%, respectively. The exposure risks of Coicis Semen to AFB_1, AFB2, ST, DON, and ZEN were low, while 86% of the samples were contaminated with two or more toxins, which needs more attention. It is suggested that the research on the combined toxicity of different mycotoxins should be strengthened to accelerate the cumulative exposure assessment of mixed contaminations and the formulation(revision) of toxin limit standards.

Rapid detection of aflatoxin B_1 in Chinese herbal medicines by indirect and direct competitive enzyme-linked immunosorbent assays: a comparative analysis / 中国中药杂志

The indirect competitive enzyme-linked immunosorbent assay(ic-ELISA) and direct competitive enzyme-linked immunosorbent assay(dc-ELISA) were performed for the rapid detection of aflatoxin B_1(AFB_1) in Astragali Radix, Zingiberis Rhizoma Recens, Jujubae Fructus, and Nelumbinis Semen with self-made antigens and antibodies. Different extraction methods were investigated to reduce the matrix effects of different medicinal parts in Chinese herbal medicines. The sensitivity of dc-ELISA method was improved by optimizing the molar ratio of AFB_1 to horseradish peroxidase(HRP). In this study, the sensitivity(IC_(50)) of ic-ELISA and dc-ELISA was 0.046 and 0.023 ng·mL~(-1), with the limit of detection(LOD) of 0.007 and 0.004 ng·mL~(-1), respectively. The detection time was 3 h and 50 min for ic-ELISA and dc-ELISA, respectively. The recovery rates were within the range of 62.96%-104.4%, with RSDs of less than 10%. Confirmed by LC-MS/MS, three positive samples of Nelumbinis Semen were detected from 53 samples. Two ELISA methods established in this study were accurate, rapid and sensitive, and can be used for rapid screening of AFB_1 in Chinese herbal medicines such as Astragali Radix, Zingiberis Rhizoma Recens, Jujubae Fructus, and Nelumbinis Semen. In addition, the advantages and limitations of the two methods were compared and discussed, which can provide a reference for the testing institutions to choose the proper method.

Validation of a liquid chromatography/tandem mass spectrometry method for the detection of aflatoxin B1 residues in broiler liver / Validación de una técnica para detectar aflatoxina B1 en hígado de pollo por cromatografía líquida de alta performance acoplada a espectrómetro de masas en tándem

Aflatoxin B1 is a carcinogenic and mutagenic mycotoxin produced mainly by Aspergillus flavus and Aspergillus parasiticus. It is the predominant mycotoxin found in raw materials used for the manufacture of broiler feeds. The aim of the present study was to develop a new and optimized method for the detection and quantification of aflatoxin B1 (AFB1) residues in broiler liver using solid phase extraction (SPE) clean-up and liquid chromatography-electrospray ionization/tandem mass spectrometry (LC-ESI-MS/MS) detection. The method was validated for linearity, accuracy, precision, limit of detection (LOD) and limit of quantification (LOQ). The validation parameters indicated satisfactory linearity (r² >0.99), accuracy and precision (4.57% intra-day RSD; 14.65% inter-day RSD) a very high recovery (99 ±13%) and high sensitivity achieved for AFB1 in animal samples (LOD = 0.017 and LOQ= 0.050 ng/g). The method was effective for the detection and quantification of AFB1 residues in broiler liver and could also be potentially used for detecting AFB1 in other edible animal tissues after natural or experimental AFB1 exposure with high sensitivity and precision.

La aflatoxina B1 (AFB1) es una micotoxina carcinogénica y mutagénica producida principalmente por Aspergillus flavus y Aspergillus parasiticus. Es la principal toxina que contamina las materias primas utilizadas para la elaboración de alimentos balanceados destinados a la alimentación de pollos parrilleros. El objetivo de este trabajo fue desarrollar un método nuevo y optimizado para detectar y cuantificar bajos niveles de AFB1 en hígado de pollo, usando limpieza por extracción en fase sólida (SPE) y cromatografía líquida acoplada a detección por espectrometría de masa en tándem con ionización por electrospray (LC-ESI-MS/MS). Se validaron la linealidad, la exactitud, la precisión, el límite de detección (LOD) y el límite de cuantificación (LOQ). El método resultó tener linealidad (r²>0,99), exactitud y precisión muy satisfactorias (4,57% RSD intradía; 14,65% RSD interdía), un alto porcentaje de recupero (99 ± 13%) y la sensibilidad más alta lograda para la detección de AFB1 en muestras de origen animal (LOQ=0.050 ng/g y LOD = 0.017). El método fue muy efectivo para detectar y cuantificar bajos niveles de AFB1 en hígados de pollos parrilleros. Este método podría potencialmente utilizarse para la detección de esta toxina en otros tejidos y subproductos de origen animal luego de su exposición a AFB1 con una mayor sensibilidad y precisión.

Efectos de la temperatura, la actividad de agua y el tiempo de incubación en el crecimiento fúngico y la producción de aflatoxina B1 por aislados toxicogénicos de Aspergillus flavus en sorgo / Effects of temperature, water activity and incubation time on fungal growth and aflatoxin B1 production by toxinogenic Aspergillus flavus isolates on sorghum seeds

Sorghum, which is consumed in Tunisia as human food, suffers from severe colonization by several toxigenic fungi and contamination by mycotoxins. The Tunisian climate is characterized by high temperature and humidity that stimulates mold proliferation and mycotoxin accumulation in foodstuffs. This study investigated the effects of temperature (15, 25 and 37 °C), water activity (a w, between 0.85 and 0.99) and incubation time (7, 14, 21 and 28 d) on fungal growth and aflatoxin B1 (AFB1) production by three Aspergillus flavus isolates (8, 10 and 14) inoculated on sorghum grains. The Baranyi model was applied to identify the limits of growth and mycotoxin production. Maximum diameter growth rates were observed at 0.99 a w at 37 °C for two of the isolates. The minimum a w needed for mycelial growth was 0.91 at 25 and 37 °C. At 15 °C, only isolate 8 grew at 0.99 a w. Aflatoxin B1 accumulation could be avoided by storing sorghum at low water activity levels (≤0.91 a w). Aflatoxin production was not observed at 15 °C. This is the first work on the effects of water activity and temperature on A. flavus growth and AFB1 production by A. flavus isolates on sorghum grains.

El sorgo, que se consume en Túnez como alimento humano, puede sufrir la colonización severa de varios hongos toxicogénicos, con la consiguiente bioacumulación de micotoxinas. Además, el clima de Túnez, caracterizado por las altas temperaturas y humedad, estimula el crecimiento fúngico y la acumulación de micotoxinas en los productos alimenticios. Este estudio investigó los efectos de la temperatura (15, 25 y 37 °C), la actividad de agua (a w) (entre 0,85 y 0,99) y el tiempo de incubación (7, 14, 21 y 28 días) sobre el crecimiento y la producción de aflatoxina B1 (AFB1) de 3 aislados de Aspergillus flavus (designados como 8, 10 y 14) que se inocularon sobre granos de sorgo. El modelo Baranyi se aplicó para identificar los límites del crecimiento y la producción de micotoxinas. Las tasas máximas de crecimiento para 2 de los aislados se observaron en la combinación 0,99 a w y 37 °C. La a w mínima necesaria para el crecimiento del micelio fue de 0,91 a 25 °C y 37 °C. A 15 °C, solo el aislado 8 creció a 0,99 a w, pero fue incapaz de producir la aflatoxina B1. Es posible evitar la acumulación de aflatoxina B1 en el sorgo almacenándolo a baja actividad de agua (≤ 0,91 a w). Este es el primer trabajo que ha estudiado el efecto de la actividad del agua y la temperatura sobre el crecimiento de aislados de A. flavus y su producción de aflatoxina B1 en granos de sorgo.

In vitro ability of beer fermentation residue and yeast-based products to bind aflatoxin B1

This study aimed to verify the in vitro ability of beer fermentation residue (BFR) containing Saccharomyces cerevisiae cells and five commercial products that differed in the viability and integrity of S. cerevisiae cells to remove aflatoxin B1 (AFB1) from a citrate-phosphate buffer solution (CPBS). BFR was collected at a microbrewery and prepared by drying and milling. The commercial yeast-based products were as follows: inactive intact yeast cells from beer alcoholic fermentation, inactive intact yeast cells from sugarcane alcoholic fermentation, hydrolyzed yeast cells, yeast cell walls and active yeast cells. Adsorption assays were performed in CPBS spiked with 1.0 μg AFB1/mL at pH 3.0 and 6.0 for a contact time of 60 min at room temperature. Analysis of AFB1 in the samples was performed by high performance liquid chromatography. AFB1 adsorption by the products ranged from 45.5% to 69.4% at pH 3.0 and from 24.0% to 63.8% at pH 6.0. The higher percentages (p < 0.05) of AFB1 binding at both pH values were achieved with products containing hydrolyzed yeast cells or yeast cell walls rather than intact cells. The AFB1 binding percentages of BFR were 55.0 ± 5.0% at pH 3.0 and 49.2 ± 4.5% at pH 6.0, which was not significantly different (p > 0.05) from commercial products containing inactive intact yeast cells. The results of this trial indicate that the yeast-based products tested, especially the BFR, have potential applications in animal feeds as a suitable biological method for reducing the adverse effects of aflatoxins.

Efficacy of aqueous garlic extract on growth, aflatoxin B1 production, and Cyto-morphological aberrations of Aspergillus flavus, causing human ophthalmic infection: topical treatment of A. flavus keratitis

By using agar well diffusion assay, antifungal activity of aqueous extract prepared from Egyptian garlic (Allium sativum L.) was evaluated in vitro against two strains of Aspergillus flavus (OC1 and OC10) causing human ocular infection. The recorded minimum inhibitory concentration (MIC) for growth inhibition of both strains was 3.60 mg/ml. Aqueous garlic extract (AGE) was used in successive in vivo tests as an attempt to cure rabbit's fungal keratitis caused by A. flavus OC1. Findings showed that diluted preparation of AGE was effective topical antifungal agent and succeeded to cure severe A. flavus keratitis in a time course less than 10 days without any observable side effects. Microscopic examination showed that AGE induced deleterious cyto-morphological aberrations inA. flavus target cells. AGE applied to Czapek's broth via contact method was more effective on growth, spores and aflatoxin B1 production than AGE applied to the same broth at the same concentration via fumigation method.

Occurrence of aflatoxin B1 in natural products

The media claims for the consumption of natural resource-based food have gradually increased in both developing and developed countries. The interest in the safety of these products is partially due to the possible presence of toxigenic fungi acting as mycotoxin producers, such as aflatoxins produced during the secondary metabolism of Aspergillus flavus, A. parasiticus and A. nomius. Aflatoxins, mainly aflatoxin B1, are directly associated with liver cancer in human beings. This paper is aimed at evaluating the presence of aflatoxin B1 in a few vegetable drugs, dried plant extracts and industrialized products traded in 2010 in the city of Belo Horizonte, State of Minas Gerais, Brazil. The method used for the quantification of aflatoxin B1 was based on extraction through acetone:water (85:15), immunoaffinity column purification followed by separation and detection in high efficiency liquid chromatography. Under the conditions of analysis, the Limits of Detection and Quantification were 0.6 µg kg-1 and 1.0 µg kg-1respectively. The complete sets of analyses were carried out in duplicate. Aflatoxin B1 was noticed in a single sample (< 1.0 µg kg-1). The results revealed low aflatoxin B1contamination in the products under analysis. However, it is required to establish a broad monitoring program in order to obtain additional data and check up on the actual extension of contamination.

Effect of gamma radiation on the inactivation of aflatoxin B1 in food and feed crops / Efeito da radiação gama na inativação de aflatoxina B1 em alimentos e ração

Samples of food crops (peanut, peeled pistachio, unpeeled pistachio, rice, and corn) and feed (barley, bran, corn) were autoclave-sterilized, and inoculated with 10(6) of spore suspension of an isolate of Aspergillus flavus fungus known to produce aflatoxin B1 (AFB1) . Following a 10-day period of incubation at 27 C to allow for fungal growth, food and feed samples were irradiated with gamma radiation at the doses 4, 6, and 10 kGy. Results indicated that degradation of AFB1 was positively correlated with the increase in the applied dose of gamma ray for each tested sample. At a dose of 10 kGy percentages of AFB1 degradation reached highest values at 58.6, 68.8, 84.6, 81.1 and 87.8 percent for peanuts, peeled pistachios, unpeeled pistachios, corn and rice samples, respectively. In feed samples percentages of AFB1 degradation were 45, 66, and 90 percent in barley, 47, 75, and 86 percent in bran, and 31, 72, and 84 percent in corn for the doses of 4, 6, and 10 kGy, respectively. AFB1 degradation in food samples correlated negatively with oil content in irradiated samples. Thus, in peanuts, which contained the highest oil content, percentage of AFB1 degradation at 10 kGy was not more than 56.6 percent, whereas, the corresponding value in corn, which contained the lowest oil content, reached as high as 80 percent. The above results indicate the possibility of using gamma radiation as a means of degradation of AFB1 in food and feed crops to levels lower than the maximum allowed levels.

Amostras de alimentos (amendoim, pistache descascada, pistache com casca, arroz e milho) e de ração (cevada, farelo de trigo e milho) foram esterilizadas por autoclavação e inoculadas com uma suspensão de esporos (10(6)) de um isolado de Aspergillus flavus produtor de aflatoxina B1 (AFB1). Após incubação por 10 dias a 27ºC para multiplicação do fungo, as amostras foram irradiadas com radiação gama nas doses de 4, 6 e 10 kGy. Os resultados indicaram que a degradação da AFB1 correlacionou-se positivamente com o aumento da dose de radiação gama. As porcentagens de degradação da AFB1 foram mais altas na dose de 10kGy, obtendo-se valores de 58,6, 68,8, 84,6, 81,1 e 87,8 por cento para amendoim, pistache descascada, pistache com casca, milho e arroz, respectivamente. Nas rações, as porcentagens de degradação de AFB1 foram 45, 66 e 90 por cento para cevada, 47, 75 e 86 por cento para farelo de trigo e 31, 72 e 84 por cento para milho, nas doses de 4, 6 e 10 kGy, respectivamente. A degradação de AFB1 correlacionou-se negativamente com o teor de gordura nas amostras irradiadas. Assim, em amendoim, que apresentou o teor de gordura mais alto, a porcentagem de degradação com 10 kGy foi inferior a 56,6 por cento, enquanto o valor correspondente em milho, que apresentou o teor de gordura mais baixo, foi de 80 por cento. Os resultados indicam a possibilidade de uso da radiação gama como meio de degradação de AFB1 em alimentos e ração a níveis inferiores ao máximo permitido.

Inactivación de aflatoxina B1 y aflatoxicol por nixtamalización tradicional del maíz y su regeneración por acidificación de la masa / Inactivation of aflatoxin B1 and aflatoxicol through traditional

OBJETIVO: Confirmar el efecto de la nixtamalización tradicional sobre la aflatoxina, identificar el compuesto remanente en masa, evaluar su toxicidad y su regeneración por tratamiento ácido. MATERIAL Y MÉTODOS: Se utilizó maíz, sin y con aflatoxina, y se nixtamalizó. La toxicidad se evaluó en pollos de ocho días de edad. Se aplicó el tratamiento ácido a la masa. La cuantificación de aflatoxinas se realizó por cromatografía líquida de alta resolución (HPLC). RESULTADOS: La nixtamalización destruyó la aflatoxina (96 por ciento) y el aflatoxicol (70 por ciento); el remanente en masa fue aflatoxina B1. El tratamiento ácido in vitro no eleva las concentraciones de ninguna de las dos micotoxinas. Los pollos murieron al ingerir 260 mg de AFB1, y la masa con aflatoxina remanente no fue tóxica. CONCLUSIONES: Los resultados ilustran el beneficio de la nixtamalización tradicional en la inactivación de las aflatoxinas presentes en maíz y en su no reconstitución por efecto del tratamiento ácido.

Eficacia y estabilidad del proceso de amonificación como tecnología de descontaminación de aflatoxina B1 en arroz (Oriza sativa) / Efficacy and stability of ammoniation process as aflatoxin B1 decontamination technology in rice

Rice, a cereal widely used in Venezuela for human and animal nutrition, is susceptible to aflatoxin contamination in the field and during storage. Therefore, the goal of this research was the evaluation of the efficacy and permanence of the ammoniation process through high pressure/high temperature (HP/HT) and atmospheric pressure/moderate temperature (AP/MT) conditions applied to rice samples artificially contaminated with aflatoxin B1. For this purpose a 2k design was drawn up considering the temperature, the rice moisture and the process time as variables. Under both sets of conditions, aflatoxin B1 concentration was reduced in a range of 90 per cent to 100 per cent. After in vitro stomach digestion simulation, toxin reversion ranged from 0 per cent to 19 per cent. In conclusion, the process efficacy and permanence were achieved through the use of high temperature and long process time for both sets of conditions (HP/HT and AP/MT), respectively.

Estudio de la relación entre aflatoxina B1 t cáncer de pulmón / Study of relatonship between lung cancer and aflatoxin B1

La relación entre el cáncer de hígado y las aflatoxinas está bien demostrada. Los productos químicos genotóxicos reaccionan con el ADN tanto en forma directa o después de la activación metabólica para formar uniones; este es un paso esencial con respecto a la carcinogénesis química. La presencia y el número de uniones específicas al ADN provee una buena indicación de la exposición química y del daño genético resultante del contacto a carcinógenos y la proporción de los mismos que afectan la susceptibilidad para padecer cáncer. Un análisis de las uniones al AND requiere metodología altamente sensible para detectar por lo menos una unión cada 109 nucleótidos normales. El método más confiable está basado en técnicas físico químicas como la cromatografía líquida de alta presión. (HPLC). Por otra parte la exposición por inhalación del carcinógeno AFB1 debe ser considerada como potencial inductora/productora de cáncer de pulmón. Así es que existen evidencias epidemiológicas circunstanciales que dicho compuesto produciría cáncer de pulmón. El propósito de esta investigación fue determinar la presencia de AFB1 en diferentes tipos de tabaco, a) Virginia de Jujuy, b) Brasileño y c) negro de Salta; así como en tejidos pulmonares obtenidos por biopsias de pacientes con cáncer de pulmón y bronquitis crónica. Los pacientes se dividieron por sus manifestaciones clínicas en: pacientes afectados con cáncer de pulmón (n:25) y aquellos que presentaban bronquitis crónica (n:14). En el grupo con cáncer de pulmón la estirpe epidermoide se presentó en 23 de 25 cánceres estudiados, todos ellos fumadores. Los otros 2 casos fueron adenocarcinoma, no fumadores. En los pacientes con bronquitis crónica se registraba el hábito de fumar en 12 de 14 casos. La determinación de AFB1 fue positiva en los tres tipos de tabaco y negativa en diluyente de PBS. Las biopsias de los carcinomas de estirpe epidermoide fueron positivas en los 23 casos, con un nivel de 0.68ñ0.82 mg/l. En los pacientes con adenocarcinoma (n:2) el resultado para AFB1 fue negativo, similar a los pacientes con bronquitis crónica (n:2) que no eran fumadores. Los 12 pacientes con bronquitis crónica, todos ellos fumadores, presentaron AFB1 en menor nivel que en el grupo cáncer epidermoide, 0.21ñ0.109 mg/l, p<.025. Conclusiones: 1º La AFB1 fue encontrada en las fuentes de tabaco , así como en el epitelio bronquial de los cánceres de estirpe epidermoide y en menor nivel en los pacientes con bronquitis crónica...

Efeito do ferro na biossíntese de aflatoxina B1 por Aspergillus flavus IMI 190443 após inoculaçäo em dois genótipos de amendoim / Effect of iron on the biosynthesis of aflatoxin B1 by Aspergillus flavus IMI 190443 after inoculation in two peanuts genotypes

Avaliou-se a produçäo de aflatoxina B1 pelo Aspergillus flavus IMI 190443 em sementes de amendoim, genótipos Tatu Vermelho e VRR-245, cultivados no Centro Experimental do Instituto Agronômico de Campinas em 1994/1995 e submetidos a adubaçäo com sulfato ferroso. Após a colheita, os gräos de amendoim foram previamente autoclavados a 121§C por minutos, e inoculados com uma suspensäo de esporos de Aspergillus flavus IMI 190443, em três concentraçöes: 10(3), 10(4), 10(5) esporos/mL. Observou-se uma menor produçäo de aflatoxina B1 no genótipo VRR-245, independente da concentraçäo de esporos de Aspergillus flavus IMI 190443 (10(3), 10(4), e 10(5) esporos/mL) e do tratamento com e sem sulfato ferroso (p<0,05), quando comparado ao Tatu Vermelho. Verificou-se uma menor contaminaçäo com aflatoxina B1 nos genótipos Tatu Vermelho e VRR-245, após adubaçäo e inoculaçäo com Aspergillus flavus IMI 190443, apenas na concentraçäo de 10(3) esporos/mL