Magnetic-Propelled Janus Yeast Cell Robots Functionalized with Metal-Organic Frameworks for Mycotoxin Decontamination.

Cell robots that transform natural cells into active platforms hold great potential to enrich the biomedical prospects of artificial microrobots. Here, we present Janus yeast cell microrobots (JYC-robots) prepared by asymmetrically coating Fe3O4 nanoparticles (NPs) and subsequent in situ growth of zeolitic imidazolate framework-67 (ZIF-67) on the surface of yeast cells. The magnetic actuation relies on the Fe3O4 NPs wrapping. As the compositions of cell robots, the cell wall with abundant polysaccharide coupling with porous and oxidative ZIF-67 can concurrently remove mycotoxin (e.g., zearalenone (ZEN)). The magnetic propulsion accelerates the decontamination efficiency of JYC-robots against ZEN. Although yeast cells with fully coating of Fe3O4 NPs and ZIF-67 (FC-yeasts) show faster movement than JYC-robots, higher toxin-removal efficacy is observed for JYC-robots compared with that of FC-yeasts, reflecting the vital factor of the yeast cell wall in removing mycotoxin. Such design with Janus modification of magnetic NPs (MNPs) and entire coating of ZIF-67 generates active cell robot platform capable of fuel-free propulsion and enhanced detoxification, offering a new formation to develop cell-based robotics system for environmental remediation.

Effects of Citric and Lactic Acid on the Reduction of Deoxynivalenol and Its Derivatives in Feeds.

Exposure to mycotoxin-contaminated feeds represents a serious health risk. This has necessitated the need for the establishment of practical methods for mycotoxin decontamination. This study investigated the effects of citric acid (CA) and lactic acid (LA) on common trichothecene mycotoxins in feeds contaminated with Fusarium mycotoxins. Contaminated feed samples were processed either with 5% CA or 5% LA solutions in a ratio of 1:1.2 (w/v) for 5, 24, or 48 h, and analyzed for multiple mycotoxin metabolites using a liquid chromatography-tandem mass spectrometric method. The analyses showed that treating the feed with CA and LA lowered the concentration of deoxynivalenol (DON), whereby 5% LA lowered the original DON concentration in the contaminated feed samples by half, irrespective of the processing time. Similar lowering effects were observed for the concentrations of 15Ac-DON, 5-hydroxyculmorin, and sambucinol. The concentration of nivalenol was only lowered by the LA treatment. In contrast, CA and LA treatments showed no or only small effects on the concentration of several mycotoxins and their derivatives, including zearalenone, fumonisins, and culmorin. In conclusion, the present results indicate that the use of 5% solutions of LA and CA might reduce the concentration of common trichothecene mycotoxins, especially DON and its derivate 15Ac-DON. However, further research is required to determine the effect on overall toxicity and to identify the underlying mechanisms.

Evaluation of the supplementation of a feed additive as a potential protector against the adverse effects of 2. 5 ppm T-2 toxin on growing broiler chickens / Avaliação da suplementação de um aditivo alimentar como um protetor potencial contra os efeitos adversos de 2, 5ppm de toxina T-2 em frangos em crescimento

A trial was conducted to evaluate a feed additive containing epoxidase activity from a bacterium (Mycofix-S) as a potential protection against the adverse effects of 2.5 ppm dietary T-2 toxin in male growing broiler chickens. A total of 144 one-day-old Ross 308 male chicks were individually wing-banded and allotted into each of the four experimental groups. Group 1: negative control, no T-2 toxin or additive; group 2: Mycofix-S, 2.5 g/kg; group 3: positive control, 2.5 ppm T-2 toxin; group 4: 2.5 ppm T-2 toxin + 2.5 g/kg Mycofix-S. Feed and water were provided ad libitum for 28 days (days 1 to 28 of age). Each experimental treatment was replicated 6 times, with 6 birds per replicate pen. Response variables included performance parameters, serum activity of alkaline phosphatase (ALP) and amylase, relative weight of selected organs and histology of the upper digestive system. T-2 toxin at 2.5 ppm significantly (P = 0.016) decreased the 28-day body weight gain and cumulative feed intake without affecting feed conversion. The feed additive counteracted these adverse effects. Serum enzyme activities were not significantly (P>0.05) affected for the four experimental groups but when data from the groups receiving T-2 toxin was pooled and compared against the pooled data from groups without the toxin a significant decrease in amylase activity was observed in chickens receiving T-2 toxin. The histological examination of the upper digestive system revealed lesions in mouth, esophagus, proventriculus, gizzard and duodenum in the chickens fed T-2 toxin without the additive. Chickens fed T-2 toxin plus the additive showed lesions in the same tissues except in the duodenum. The results of the present study show that the addition of 2.5 g/kg of the feed additive tested protects against adverse effects on performance and also the integrity of the duodenal mucosa.(AU)

Foi realizado um experimento com o objetivo de avaliar um aditivo alimentar contendo atividade de epoxidase de uma bactéria (Mycofix-S) como proteção potencial contra os efeitos adversos de uma dieta com 2,5ppm de toxina T-2 em frangos de corte machos. Um total de 144 pintos machos Ross 308 de um dia de idade foram marcados na asa individualmente e alocados em um de quatro grupos experimentais: grupo 1: controle negativo, sem toxina T-2 ou aditivo; grupo 2: 2,5g/kg de Mycofix-S; grupo 3: controle positivo, 2,5ppm de toxina T-2; grupo 4: 2,5ppm de toxina T-2 + 2,5g/kg de Mycofix-S. Alimento e água foram fornecidos ad libitum por 28 dias (dias um a 28 de idade). Cada tratamento experimental foi replicado seis vezes, com seis pintos por gaiola de replicação. As variáveis de resposta incluíram parâmetros de desempenho, atividade sérica de fosfatase alcalina (ALP) e amilase, peso relativo de órgãos selecionados e histologia do sistema digestivo superior. A toxina T-2 a 2,5ppm diminuiu significativamente (P = 0.016) o ganho de peso corporal aos 28 dias e o consumo de alimento acumulado, sem afetar a conversão alimentar. O aditivo diminuiu os efeitos adversos. As atividades séricas das enzimas não foram afetadas significativamente (P>0.05) nos quatro grupos experimentais, porém, quando os dados dos grupos que receberam a toxina T-2 foram combinados e comparados com o pool de dados dos grupos sem toxina, foi observado um decréscimo significativo da atividade de amilase nos frangos que receberam a toxina T-2. O exame histológico do sistema digestivo superior revelou lesões em boca, esôfago, pró-ventrículo, moela e duodeno nos frangos alimentados com toxina T-2 sem aditivo. Frangos alimentados com toxina T-2 mais aditivo mostraram lesões nos mesmos tecidos, exceto no duodeno. Os resultados do presente estudo mostram que a adição de 2,5g/kg do aditivo alimentar testado protege contra os efeitos adversos sobre o desempenho e a integridade da mucosa duodenal.(AU)

Effectiveness of hand sorting, flotation/washing, dehulling and combinations thereof on the decontamination of mycotoxin-contaminated white maize.

Maize is one of the major staple foods of Sub-Saharan Africa and is consumed as whole or dehulled grain. In this region, where the environmental conditions favour fungal growth and mycotoxin production, the majority of the population are subsistence consumers who, unfortunately, have little or no access to mycotoxin testing of their food. In an attempt to develop feasible reduction strategies in dietary mycotoxin exposure of the population, a three-factorial design experiment was conducted to examine and compare the efficacy of hand sorting, flotation, dehulling and combinations thereof in removing naturally occurring aflatoxins, fumonisins, nivalenol, deoxynivalenol and alternariol in shelled white maize. Regression analysis was used to determine the significant (p < 0.05) process variables on the removal of mycotoxins from the maize. Results from this experiment indicated that hand sorting had the greatest effect on mycotoxin removal, while flotation yielded the least effect. In particular hand sorting left < 6% of aflatoxin B1 and < 5% of fumonisin B1. Based on these results, hand sorting of maize grains is being recommended as a last line of defence against mycotoxin exposure among subsistence consumers.