A review of the mycotoxin adsorbing agents, with an emphasis on their multi-binding capacity, for animal feed decontamination

Microbial synthesis of zinc oxide nanoparticles and their potential application as an antimicrobial agent and a feed supplement in animal industry: a review

In recent years, zinc oxide nanoparticles (ZnO NPs) have gained tremendous attention attributed to their unique properties. Notably, evidence has shown that zinc is an important nutrient in living organisms. As such, both prokaryotes and eukaryotes including bacteria, fungi and yeast are exploited for the synthesis of ZnO NPs by using microbial cells or enzyme, protein and other biomolecules compounds in either an intracellular or extracellular route. ZnO NPs exhibit antimicrobial properties, however, the properties of nanoparticles (NPs) are depended upon on their size and shape, which make them specific for various applications. Nevertheless, the desired size and shape of NPs can be obtained through the optimization process of microbes mediated synthesis by manipulating their reaction conditions. It should be noted that ZnO NPs are synthesized by various chemical and physical methods. Nonetheless, these methods are expensive and not environmentally friendly. On that account, the microbes mediated synthesis of ZnO NPs have rapidly evolved recently where the microbes are cleaner, eco-friendly, non-toxic and biocompatible as the alternatives to chemical and physical practices. Moreover, zinc in the form of NPs is more effective than their bulk counterparts and thus, they have been explored for many potential applications including in animals industry. Notably, with the advent of multi-drug resistant strains, ZnO NPs have emerged as the potential antimicrobial agents. This is mainly due to their superior properties in combating a broad spectrum of pathogens. Moreover, zinc is known as an essential trace element for most of the biological function in the animal's body. As such, the applications of ZnO NPs have been reported to significantly enhance the health and production of the farm animals. Thus, this paper reviews the biological synthesis of ZnO NPs by the microbes, the mechanisms of the biological synthesis, parameters for the optimization process and their potential application as an antimicrobial agent and feed supplement in the animal industry as well as their toxicological hazards on animals.

Probiotic microorganisms detoxify ochratoxin A in both a chicken liver cell line and chickens

BACKGROUND

The administration of probiotics and prebiotics (synbiotics) is a promising method for detoxification of ochratoxin A (OTA) in animals. The aim of this study was to investigate the ability of five probiotic strains of lactic acid bacteria (LAB) and one Saccharomyces cerevisiae yeast strain, from three different synbiotics for poultry, to detoxify OTA. In addition, we also investigated the genotoxicity of faecal water (FW) of chickens after administering OTA and/or synbiotics for 42 days.

RESULTS

All tested LAB and yeast strains had the ability to detoxify OTA by significant (P < 0.05) reducing its concentration (by 31.3-47.7% and 31.9%, respectively, after 24 h incubation) and genotoxicity (by 22.6-51.8% and 52.7%, respectively). Synbiotics composed of four and five probiotic strains significantly (P < 0.05) decreased FW genotoxicity of chicks, after exposure to OTA, to the level seen in the control group (21.8% ± 1.7%) and were more effective than synbiotics composed of three probiotic strains (31.5%).

CONCLUSION

These results showed that there was a beneficial effect of the synbiotics on the gastrointestinal tract of animals. Furthermore, synbiotic preparations containing four or five of tested strains can be considered as preventive agents in the contamination of poultry with OTA. © 2019 Society of Chemical Industry.

Aflatoxin B1-Adsorbing Capability of Pleurotus eryngii Mycelium: Efficiency and Modeling of the Process

Aflatoxin B₁ (AfB₁) is a carcinogenic mycotoxin that contaminates food and feed worldwide. We determined the AfB₁-adsorption capability of non-viable Pleurotus eryngii mycelium, an edible fungus, as a potential means for removal of AfB₁ from contaminated solutions. Lyophilized mycelium was produced and made enzymatically inert by sterilization at high temperatures. The material thus obtained was characterized by scanning electron microscopy with regard to the morpho-structural properties of the mycotoxin-adsorbing surfaces. The active surfaces appeared rough and sponge-like. The AfB₁-mycelium system reached equilibrium at 37°C, 30 min, and pH 5–7, conditions that are compatible with the gastro-intestinal system of animals. The system remained stable for 48 h at room temperature, at pH 3, pH 7, and pH 7.4. A thermodynamic study of the process showed that this is a spontaneous and physical adsorption process, with a maximum of 85 ± 13% of removal efficiency of AfB₁ by P. eryngii mycelium. These results suggest that biosorbent materials obtained from the mycelium of the mushroom P. eryngii could be used as a low-cost and effective feed additive for AfB₁ detoxification.

Candida utilis ATCC 9950 Cell Walls and β(1,3)/(1,6)-Glucan Preparations Produced Using Agro-Waste as a Mycotoxins Trap

Mycotoxins are harmful contaminants of food and feed worldwide. Feed additives with the abilities to trap mycotoxins are considered substances which regulate toxin transfer from feed to tissue, reducing its absorption in animal digestive tract. Market analysis emphasizes growing interest of feed producers in mycotoxins binders obtained from yeast biomass. The aim of the study was to prescreen cell walls (CW) and β(1,3)/(1,6)-glucan (β-G) preparations isolated from Candida utilis ATCC 9950 cultivated on waste potato juice water with glycerol as adsorbents for aflatoxin B1 (AFB1), zearalenone (ZEN), ochratoxin A (OTA), deoxynivalenol (DON), nivalenol (NIV), T-2 toxin (T-2) and fumonisin B1 (FB1). The adsorption was studied in single concentration tests at pH 3.0 and 6.0 in the presence of 1% of the adsorbent and 500 ng/mL of individual toxin. Evaluated CW and β-G preparations had the potential to bind ZEN, OTA and AFB1 rather than DON, NIV, T-2 toxin and FB1. The highest percentage of adsorption (about 83%), adsorption capacity (approx. 41 µg/ g preparation) and distribution coefficient (458.7mL/g) was found for zearalenone when CW preparation was used under acidic conditions. Higher protein content in CW and smaller particles sizes of the formulation could influence more efficient binding of ZEN, OTA, DON and T-2 toxin at appropriate pH compared to purified β-G. Obtained results show the possibility to transform the waste potato juice water into valuable Candida utilis ATCC 9950 preparation with mycotoxins adsorption properties. Further research is important to improve the binding capacity of studied preparations by increasing the active surface of adsorption.

Comparative efficacy of agricultural by-products in sequestering mycotoxins

BACKGROUND

Biosorption using agricultural by-products has been proven as a low-cost and safe way to sequester mycotoxins. Few agricultural by-products have been studied for their efficacy in adsorbing simultaneously a large range of mycotoxins. The present work compared the ability of 51 agricultural by-products to adsorb mycotoxins from liquid mediums simulating physiological pH values, and it studied the mechanism for mycotoxin adsorption by isotherm adsorption experiments.

RESULTS

Grape pomaces, artichoke wastes, and almond hulls were selected as promising biosorbents for mycotoxins, being quite effective towards aflatoxin B₁ (AFB₁ ), zearalenone (ZEA), and ochratoxin A (OTA). Their adsorption was not affected by medium pH, and the adsorbed fraction was not released when pH rose from acid to neutral values. Fumonisin B₁ (FB₁ ) was adsorbed to a lesser extent, and deoxynivalenol adsorption was not recorded. For the selected biosorbents, maximum adsorption capacity calculated by the best fitting model (Freundlich, Langmuir, or Sips equation) ranged from 1.2 to 2.9 µg mg^-1 for AFB₁ , 1.3 to 2.7 µg mg^-1 for ZEA, 0.03 from 2.9 µg mg^-1 for OTA, and 0.01-1.1 µg mg^-1 for FB₁ .

CONCLUSION

This study confirms that some agricultural by-products can find technological applications as feed/food additives for mycotoxin reduction. © 2018 Society of Chemical Industry.

Fossil Shell Flour in Livestock Production: A Review

Fossil shell flour (FSF), also known as Diatomaceous earth, or diatomite, consists of amorphous silicates with important physical and chemical characteristics, including porosity and permeability, low density and thermal conductivity, tiny particle size, high surface area, solubility, hydrophobia, and absorption capabilities, which are molecular filter actors, substituting their integral cations without physical changes. The substance is nontoxic, cheap, and readily available in large quantity in many countries. Recently, FSF has been modified as additives for several uses. Recent studies have supported its use as animal growth promoter, vaccine adjuvant in livestock, water purifier, mycotoxin binder, inert dust applications in stored-pest management, pesticide, animal feed additive, as a natural source of silicon in livestock and as natural anthelmintic. Numerous advantages of FSF include its low-cost and availability, its nontoxic characteristics, and the fact that food grade diatomaceous earth is safe for human consumption. In this paper, we review the main uses of FSF in the livestock industry, with reference to similar works earlier published that elucidate their important roles.

Evaluation of Cellulosic Polymers and Curcumin to Reduce Aflatoxin B1 Toxic Effects on Performance, Biochemical, and Immunological Parameters of Broiler Chickens

To evaluate the effect of cellulosic polymers (CEL) and curcumin (CUR) on aflatoxin B1 (AFB1) toxic effects on performance, and the biochemical and immunological parameters in broiler chickens, 150 one-day-old male broiler chicks were randomly allocated into five groups with three replicates of 10 chickens per pen: Negative Control (feed); AFB1 (feed + 2 ppm AFB1); CUR (feed + 2 ppm AFB1 + Curcumin 0.2%); CEL (feed + 2 ppm AFB1 + 0.3% Cellulosic polymers); and, CEL + CUR (feed + 2 ppm AFB1 + 0.3% Cellulose polymers + 0.2% Curcumin). Every week, body weight, body weight gain, feed intake, and feed conversion ratio were calculated. On day 21, liver, spleen, bursa of Fabricius, and intestine from five broilers per replicate per group were removed to obtain relative organ weight. Histopathological changes in liver, several biochemical biomarkers, antibody titers, and muscle and skin pigmentation were also recorded. Dietary addition of 0.3% CEL and 0.2% CUR separately significantly diminished some of the toxic effects resulting from AFB1 on performance parameters, relative organs weight, histopathology, immune response, and serum biochemical variables (P < 0.05); however, the combination of CUR and CEL showed a better-integrated approach for the management of poultry health problems that are related with the consumption of AFB1, since they have different mechanisms of action with different positive effects on the responses of broiler chickens.

Modified Palygorskite Improves Immunity, Antioxidant Ability, Intestinal Morphology, and Barrier Function in Broiler Chickens Fed Naturally Contaminated Diet with Permitted Feed Concentrations of Fusarium Mycotoxins

This study investigated effects of modified palygorskite (MPal) on immunity, antioxidant capacity, and intestinal barrier integrity in broiler chickens challenged with permitted feed Fusarium mycotoxin concentrations. One-day-old chicks were allocated into three treatments with eight replicates. Chickens in three groups were fed a basal diet with normal corn (control), contaminated diet containing moldy corn, with Fusarium mycotoxins contents in the diets lower than permitted feed mycotoxin concentrations, and the contaminated diet supplemented with 1 g/kg MPal for 42 days, respectively. Compared with control, moldy corn decreased bursa of Fabricius weight, jejunal secreted immunoglobulin A concentration, ileal superoxide dismutase (SOD) activity, jejunal and ileal villus height (VH) and VH/crypt depth (CD) ratio, and jejunal zonula occludens-1 and mucin 2 mRNA abundances at 42 days as well as ileal VH/CD ratio at 21 days; while they increased jejunal malondialdehyde accumulation at 21 and 42 days, jejunal SOD activity at 21 days, and serum diamine oxidase activity at 42 days, which were almost recovered by MPal. Moreover, dietary MPal upregulated ileal claudin-2 mRNA abundance compared with other two groups. The results indicated that MPal addition exerted protective effects on immunity, oxidative status, and intestinal barrier integrity in chickens challenged with permitted feed Fusarium mycotoxins levels.

Antibody Microarray Immunoassay for Simultaneous Quantification of Multiple Mycotoxins in Corn Samples

We developed and tested a prototype of an antibody microarray immunoassay for simultaneous quantitative detection of four typical mycotoxins (aflatoxin B₁, ochratoxin A, zearalenone, and fumonisin B₁) in corn samples. The test kit consisted of a nitrocellulose membrane layered with immobilized monoclonal antibodies against mycotoxins. During the assay, the mycotoxin-protein conjugates were biotinylated. The signal detection was enhanced by a combination of the biotin-streptavidin system and enhanced chemiluminescence (ECL). This improved the sensitivity of the assay. Under the optimized conditions, four calibration curves with goodness of fit (R² > 0.98) were plotted. The results showed that the detection limits for aflatoxin B₁, ochratoxin A, zearalenone, and fumonisin B₁ were 0.21, 0.19, 0.09, and 0.24 ng/mL, with detection ranges of 0.47⁻55.69, 0.48⁻127.11, 0.22⁻31.36, and 0.56⁻92.57 ng/mL, respectively. The limit of detection (LOD) of this antibody microarray for aflatoxin B₁, ochratoxin A, zearalenone, and fumonisin B₁ in corn was 5.25, 4.75, 2.25, and 6 μg/kg, respectively. The recovery rates from the spiked samples were between 79.2% and 113.4%, with coefficient of variation <10%. The results of the analysis of commercial samples for mycotoxins using this new assay and the liquid chromatography-tandem mass spectrometry (LC-MS/MS) were comparable and in good agreement. This assay could also be modified for the simultaneous detection of other multiple mycotoxins, as well as low-weight analytes, hazardous to human health.

Development of a Magnetic Nanoparticles-Based Screen-Printed Electrodes (MNPs-SPEs) Biosensor for the Quantification of Ochratoxin A in Cereal and Feed Samples

A rapid and sensitive electrochemical biosensor based on magnetic nanoparticles and screen-printed electrodes (MNPs-SPEs sensor) was developed for the detection of ochratoxin A (OTA) in cereal and feed samples. Different types of magnetic nanoparticles-based ELISA (MNPs-ELISA) were optimized, and the signal detection, as well as sensitivity, was enhanced by the combined use of screen-printed electrodes (SPEs). Under the optimized conditions, the calibration curve of the MNPs-SPEs sensor was y = 0.3372x + 0.8324 (R² = 0.9805). The linear range of detection and the detection limit were 0.01–0.82 ng/mL and 0.007 ng/mL, respectively. In addition, 50% inhibition (IC50) was detectable at 0.10 ng/mL. The limit of detection (LOD) of this MNPs-SPEs sensor in cereal and feed samples was 0.28 μg/kg. The recovery rates in spiked samples were between 78.7% and 113.5%, and the relative standard deviations (RSDs) were 3.6–9.8%, with the coefficient of variation lower than 15%. Parallel analysis of commercial samples (corn, wheat, and feedstuff) showed a good correlation between MNPs-SPEs sensor and liquid chromatography tandem mass spectrometry (LC/MS-MS). This new method provides a rapid, highly sensitive, and less time-consuming method to determine levels of ochratoxin A in cereal and feedstuff samples.

Effects of Feeding a Mycotoxin Binder on Nutrient Digestibility, Alkaloid Recovery in Feces, and Performance of Lambs Fed Diets Contaminated with Cereal Ergot

As contamination with cereal ergot has been increasing in western Canada, this study evaluated impacts of feeding a mycotoxin binder (Biomin^® II; BB) on nutrient digestibility, alkaloid recovery in feces, and lamb growth performance. Forty-eight ram lambs (25.9 ± 1.4 kg) were randomly assigned to one of four barley-based diets: Control (C), no added alkaloids, Control + BB fed at 30 g/head per day (CBB); Ergot, 2564 ppb total R + S epimers (E); Ergot + BB, 2534 ppb R + S epimers (EBB). Lambs were fed ab libitum for up to 11 weeks until slaughter at >46 kg live weight. Both average daily gain (ADG) and gain/feed ratio were greater (p < 0.01) for lambs fed C and CBB diets as compared with those containing added ergot, although dry matter intake was not affected by dietary ergot or BB. Serum prolactin concentrations were two times higher in EBB- compared with E-fed lambs (p < 0.05), although both were lower than in C or CBB (p < 0.001) lambs. Rectal temperatures were greater in lambs receiving dietary ergot (p ≤ 0.001) than in C- and CBB-fed lambs. In a digestibility study using eight ram lambs, treatment with BB increased neutral detergent fiber (NDF) digestibility (p = 0.01). Nitrogen retention (g) was greater (p < 0.05) for lambs receiving C or CBB compared with ergot-contaminated diets. Feces of EBB lambs had 38.5% greater (p < 0.001) recovery of alkaloids compared with those fed E. Based on sparing of prolactin, BB may reduce impacts of ergot alkaloids by increasing their excretion in feces. Accordingly, concentrations of dietary alkaloids, which would not harm sheep, would be increased by feeding BB.

Combination of Selenomethionine and N-Acetylcysteine Alleviates the Joint Toxicities of Aflatoxin B1 and Ochratoxin A by ERK MAPK Signal Pathway in Porcine Alveolar Macrophages

Our previous studies showed that aflatoxin B1 (AFB1) and ochratoxin A (OTA) could trigger joint immune toxicity. Little is known about the combined effects of selenomethionine (SeMet) and N-acetylcysteine (NAC) on the joint toxicities of the two toxins. In this study, results showed that SeMet or NAC alone or in combination significantly alleviated the downswing of cell viability, glutathione production, and phagorytosis induced by AFB1 and OTA in porcine alveolar macrophages. The uptrend of lactate dehydrogenase activities, apoptosis, reactive oxygen species levels, and the relative mRNA of inflammatory cytokines triggered by the two toxins was decreased. Combination of them was more effective than single application. Knockdown of p38, c-JUN N-terminal kinase (JNK), or extracellular signal-regulated kinase (ERK) via use of the corresponding specific siRNA could alleviate the joint toxicities of AFB1 and OTA. However, the ERK but not p38 or JNK pathway was involved in the protection of SeMet and NAC against the immunotoxicity. In conclusion, combination of SeMet and NAC might be a new therapeutic orientation for preventing the joint toxicities induced by AFB1 and OTA.

Probiotic characteristics and zearalenone-removal ability of a Bacillus licheniformis strain

Zearalenone (ZEN) is a mycotoxin produced by Fusarium species, which is one of the main animal feed contaminants causing reproductive disorders in livestock. The aim of this study was to evaluate the probiotic characteristics and ZEN removal ability of a Bacillus licheniformis strain CK1. The probiotic properties, including acidic tolerance, bile salt tolerance, adherence capability, and anti-pathogenic activities of CK1 were evaluated. CK1 survived after incubation at pH 2.0 or 3.0 for 3 h, grew well in LB broth containing 0.3% oxgall, possessed adherence capability to Caco-2 cells, and inhibited the growth of Escherichia coli O157:H7 and Listeria monocytogenes. The ZEN removal ability of CK1 was compared with a mineral mycotoxin-adsorbing agent, hydrated sodium calcium aluminosilicate (HSCAS), and a well-characterized biological mycotoxin-adsorbing agent, Lactobacillus rhamnosus GG (LGG). At 37°C in phosphate-buffered saline (PBS, pH 7.0) containing 5 μg mL^-1 of ZEN, the ZEN removal percentage of CK1 was 73.0%, which was significantly higher than that of HSCAS and LGG (45.9% and 48.4%, respectively). In the pH range of 2.5–8.0, CK1 removed up to 65% of ZEN. At temperatures between 4 and 42°C, CK1 removed more than 75% of ZEN. In the adsorption stability analysis, the amounts of ZEN removed by CK1 was over 30% even after five consecutive rounds of washing procedures. These findings demonstrated that CK1 displayed probiotic characteristics and removed ZEN effectively. Therefore, CK1 has a great potential for the development of feed additive to remove ZEN.