The Capacity of Manno-Oligosaccharides, Thermolysed Yeast and Active Yeast to Attenuate Aflatoxicosis

How does active yeast supplementation reduce the deleterious effects of aflatoxins in Wistar rats? A radiolabeled assay and histopathological study

The aim of this study was to investigate the mechanisms by which yeasts (Saccharomyces cerevisiae) control the toxic effects of aflatoxins, which are not yet fully understood. Radiolabeled aflatoxin B1 (AFB13H) was administered by gavage to Wistar rats fed with aflatoxin (AflDiet) and aflatoxin supplemented with active dehydrated yeast Y904 (AflDiet + Yeast). The distribution of AFB13H and its metabolites were analyzed at 24, 48 and 72 h by tracking back of the radioactivity. No significant differences were observed between the AflDiet and AflDiet + Yeast groups in terms of the distribution of labeled aflatoxin. At 72 h, for the AflDiet group the radiolabeled aflatoxin was distributed as following: feces (79.5%), carcass (10.5%), urine (1.7%), and intestine (7.4%); in the AflDiet + Yeast the following distribution was observed: feces (76%), carcass (15%), urine (2.9%), and intestine (4.9%). These values were below 1% in other organs. These findings indicate that even after 72 h considerable amounts of aflatoxins remains in the intestines, which may play a significant role in the distribution and metabolism of aflatoxins and its metabolites over time. The presence of yeast may not significantly affect this process. Furthermore, histopathological examination of hepatic tissues showed that the presence of active yeast reduced the severity of liver damage caused by aflatoxins, indicating that yeasts control aflatoxin damage through biochemical mechanisms. These findings contribute to a better understanding of the mechanisms underlying the protective effects of yeasts against aflatoxin toxicity.

Bioremoval of Cylindrospermopsis raciborskii cells and cylindrospermopsin toxin in batch culture by the yeast Aureobasidium pullulans

This study describes the ability of a yeast strain, Aureobasidium pullulans KKUY0701 isolated from eutrophic lake to eliminate Cylindrospermopsis raciborskii and cylindrospermopsin (CYN) toxin. The anti-cyanobacterial activity of this yeast strain was evaluated by growing with living cells and filtrate of C. raciborskii. CYN bioremoval was assayed using living and heat-inactivated yeast cells. Both living cells and filtrate of this yeast strain were able to suppress the growth of C. raciborskii, with total cell death occurring at day 2 and day 3, respectively. Living and inactivated yeast cells, but not yeast filtrate, reduced CYN concentrations released into cyanobacterial cultures, indicating that this toxin might be removed from the culture medium via absorption onto yeast surface rather than enzymatic biodegradation. The adsorption experiments also confirmed the elimination of CYN by living and heat-inactivated yeast. Nevertheless, inactivated yeast exhibited higher capacity (K = 3.3) and intensity (n = 1.4) than living yeast (K = 1.9, n = 1) for CYN adsorption. The study suggests that this yeast strain could be employed for bioremediation of Cylindrospermopsis blooms in freshwaters. Additionally, heat-inactivated yeast biomass could be used in slow sand filters for elimination of CYN in drinking water treatment plants.

Applications of Probiotic-Based Multi-Components to Human, Animal and Ecosystem Health: Concepts, Methodologies, and Action Mechanisms

Probiotics and related preparations, including synbiotics and postbiotics, are living and non-living microbial-based multi-components, which are now among the most popular bioactive agents. Such interests mainly arise from the wide range and numerous beneficial effects of their use for various hosts. The current minireview article attempts to provide an overview and discuss in a holistic way the concepts, methodologies, action mechanisms, and applications of probiotic-based multi-components in human, animal, plant, soil, and environment health. Probiotic-based multi-component preparations refer to a mixture of bioactive agents, containing probiotics or postbiotics as main functional ingredients, and prebiotics, protectants, stabilizers, encapsulating agents, and other compounds as additional constituents. Analyzing, characterizing, and monitoring over time the traceability, performance, and stability of such multi-component ingredients require relevant and sensitive analytical tools and methodologies. Two innovative profiling and monitoring methods, the thermophysical fingerprinting thermogravimetry-differential scanning calorimetry technique (TGA-DSC) of the whole multi-component powder preparations, and the Advanced Testing for Genetic Composition (ATGC) strain analysis up to the subspecies level, are presented, illustrated, and discussed in this review to respond to those requirements. Finally, the paper deals with some selected applications of probiotic-based multi-components to human, animal, plant, soil and environment health, while mentioning their possible action mechanisms.

Effect of Saccharomyces cerevisiae addition to feed contaminated with aflatoxin B1 on the health and performance indices of tambaqui (Colossoma macropomum) fingerlings

The objective of this study was to evaluate the effects of the addition of Saccharomyces cerevisiae to feed contaminated with aflatoxin B1 (AFB1) on the performance and health of tambaqui fingerlings. A fully randomised study design was used, represented by four treatments: (T1) with 0.0 μg/kg of AFB1 and 0.0 colony forming unit (cfu)/g of yeast (control); (T2) with 0.0 μg/kg of AFB1 and 106 cfu/g of yeast; (T3) with 100 μg/kg of AFB1 and 0.0 cfu/g of yeast and (T4) with 100 μg/kg of AFB1 and 106 cfu/g of yeast, with four repetitions per treatment. Over a period of 34 days, 192 fingerlings with an initial weight of 2.9±0.2 g and length of 26.1±1.3 mm were used, distributed in 16 tanks with 12 fish per experimental unit. The following parameters were evaluated: water quality, zootechnical performance, histopathological analysis, counting and isolation of yeasts from the feed and intestine. No significant differences were observed (P>0.05) in the initial weight, initial length, final length, specific growth rate, mean length gain, Fulton condition factor (K Factor) or survival rate of the tambaqui fingerlings during the trial period. Statistical differences (P<0.05) were found between the treatments with respect to fingerling final weight, mean weight gain and average feed intake. Histopathological changes in the liver and kidney tissues from tambaqui fingerlings were more pronounced in T3 and T4. Based on histopathological findings, the yeast was unable to reduce the characteristic effects of aflatoxicosis in tambaqui fingerlings fed with 100 μg/kg AFB1. The S. cerevisiae A8L2 strain was able to colonise the intestine of tambaqui fingerlings, however, its addition in conjunction with 100 μg/kg AFB1 to fingerling feed did not promote improvements in performance indices or the histopathological parameters of these animals.

Enhancement of β-Glucan Biological Activity Using a Modified Acid-Base Extraction Method from Saccharomyces cerevisiae

Beta glucan (β-glucan) has promising bioactive properties. Consequently, the use of β-glucan as a food additive is favored with the dual-purpose potential of increasing the fiber content of food products and enhancing their health properties. Our aim was to evaluate the biological activity of β-glucan (antimicrobial, antitoxic, immunostimulatory, and anticancer) extracted from Saccharomyces cerevisiae using a modified acid-base extraction method. The results demonstrated that a modified acid-base extraction method gives a higher biological efficacy of β-glucan than in the water extraction method. Using 0.5 mg dry weight of acid-base extracted β-glucan (AB extracted) not only succeeded in removing 100% of aflatoxins, but also had a promising antimicrobial activity against multidrug-resistant bacteria, fungi, and yeast, with minimum inhibitory concentrations (MIC) of 0.39 and 0.19 mg/mL in the case of resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa, respectively. In addition, AB extract exhibited a positive immunomodulatory effect, mediated through the high induction of TNFα, IL-6, IFN-γ, and IL-2. Moreover, AB extract showed a greater anticancer effect against A549, MDA-MB-232, and HepG-2 cells compared to WI-38 cells, at high concentrations. By studying the cell death mechanism using flow-cytometry, AB extract was shown to induce apoptotic cell death at higher concentrations, as in the case of MDA-MB-231 and HePG-2 cells. In conclusion, the use of a modified AB for β-glucan from Saccharomyces cerevisiae exerted a promising antimicrobial, immunomodulatory efficacy, and anti-cancer potential. Future research should focus on evaluating β-glucan in various biological systems and elucidating the underlying mechanism of action.

Identification of degradation products of aflatoxin B1 and B2 resulting after their biodetoxification by aqueous extracts of Acacia nilotica

Contamination of food and feed items with mycotoxins causes extensive economic damage. It is therefore important to explore environmentally friendly approaches to manage these toxins with less drawbacks. Phytochemicals can provide a safe alternative to synthetic chemicals. This study was designed to investigate the detoxification potential of water-based extracts of Acacia nilotica against aflatoxins B1 and B2. First trials were carried out to standardise temperature, pH and incubation time for biodetoxification in spiked maize. A significant percentage of detoxification was observed under all tested conditions, showing an increasing detoxifying potential with an increase in all three parameters. Leaf extract was found to be more effective than shoot extract. Leaf extract resulted in 86-90% detoxification of both aflatoxin B1 and B2 when incubated for 72 h at 60 °C and pH 10. To avoid the detrimental effects of very high temperature and pH, experiments on spiked maize were conducted at 30 °C and pH 8. A significant detoxification of 82-83% was recorded during trials with spiked maize. MS/MS analyses showed conversion of aflatoxins B1 into seven and aflatoxins B2 into two new compounds. Most of the compounds were formed due to the removal of the double bond in the terminal furan ring and modification of the lactone group, indicating less toxicity as compared to the parent compounds. Decontamination and reduction in toxicity of treated aflatoxins was corroborated by a brine shrimps bioassay.

Growth inhibition of Microcystis aeruginosa and adsorption of microcystin toxin by the yeast Aureobasidium pullulans, with no effect on microalgae

This study evaluates the inhibitory effect of a yeast strain, Aureobasidium pullulans KKUY0701, isolated from decayed cyanobacterial bloom against harmful cyanobacterium Microcystis aeruginosa and determines the ability of this strain to remove microcystin (MC) toxin from the water. The antialgal activity of this yeast strain was assayed by co-cultivation with M. aeruginosa, diatom, and green algal species. The MC adsorption experiment was conducted in the presence of living and heat-inactivated yeast cells. Both yeast cells and filtrates caused a rapid reduction in the growth of M. aeruginosa, with complete death and cell lysis occurring after 3 days. The yeast strain did not exhibit any inhibitory effect on either green algae or diatoms. Both living and heat-inactivated yeast cells were capable of adsorption of MC on their surfaces. Inactivated yeast exhibited higher adsorption capacity and lower intensity than living yeast for the adsorption of MC toxin. The results of this study suggest that this yeast strain could be employed to selectively reduce cyanobacterial blooms in freshwaters. Moreover, the application of heat-inactivated yeast's biomass for toxin adsorption gives new possibilities in drinking water treatment plants.

Zearalenone and its metabolites: Effect on human health, metabolism and neutralisation methods

Mycotoxins are natural compounds produced as secondary metabolites by mold fungi belonging mainly to the Fusarium family, commonly found on plants such as corn or small grains in the temperate climate zone. One of these mycotoxins is zearalenone, which is classified as a xenoestrogen, an exogenous compound which resembles the structure of naturally occurring estrogens with its chemical structure. This property of zearalenone determines its ability to bind to estrogen receptors of cell and its bioaccumulation. This leads to disorders of the hormonal balance of the body, which in consequence may lead to numerous diseases of reproductive system such as prostate, ovarian, cervical or breast cancers. High risk posed by long-term exposure to contaminated food forces the modern science to develop and implement effective methods of zearalenone neutralisation. This work is a review of current state of knowledge on toxic effects of zearalenone, its metabolism in biological systems and proposed methods of its neutralisation.

The Effect of Probiotic Supplementation on Performance and the Histopathological Changes in Liver and Kidneys in Broiler Chickens Fed Diets with Aflatoxin B₁

The aim of the study was to investigate the toxic effects of aflatoxin B₁ (AFB₁) and efficacy of a probiotic preparation containing L. reuteri, L. plantarum, L. pentosus, L. rhamnosus and L. paracasei and Saccharomyces cerevisiae yeasts to ameliorate their effects in broiler chickens. A total of 168 one-day-old female Ross 308 broilers were randomly allocated to six groups. Three wheat and soybean meal-based diets were prepared: Control diet and diets contaminated with 1 or 5 mg/kg AFB₁ supplied in moldy wheat. All diets were unsupplemented or supplemented with probiotic, cold pelleted and fed from 1 to 35 day of life. Feeding diet with 1 mg AFB₁/kg did not affect performance, but a diet with 5 mg AFB₁ resulted in a significant reduction of feed intake and BWG, both diets induced liver and kidneys enlargement. The probiotic supplementation of the diets partially ameliorated those negative effects and resulted in a significant increase of AFB₁ excretion. It was accompanied by the reduced level of AFB₁ residues in the liver from 8.9 to 3.7 and from 11.8 to 5.9 µg/kg, in kidneys from 7.9 to 2.5 and from 13.7 to 4.1 µg/kg in birds fed the less and more contaminated diets, respectively. AFB₁ exposure caused many severe histopathological changes in the liver and kidneys of broilers, probiotic supplementation significantly reduced the changes of these organs. It may be concluded that the probiotic supplementation can be used to alleviate the negative effects of contamination of broiler feed with AFB₁ on bird health and product security.

Effects on the color, taste, and anthocyanins stability of blueberry wine by different contents of mannoprotein

Blueberry wine is a new fruit wine with good taste and rich nutrition, but color change and anthocyanins (ACNs) content readily decrease during the production process. The effects of different content (0.2 g/L, 0.25 g/L, and 0.3 g/L) of mannoprotein (MP) on the blueberry wine were investigated in this study. The result showed that MP treatment inhibited the decrease in ACN content, reduced the content of total acid, increased the content of alcohol content in blueberry wine, maintained the color and improved the taste of blueberry wine. In addition, the effect was more pronounced as the MP concentration increased, with the optimum effect at 0.3 g/L. However, MP has no significant effect on the total sugar in blueberry wine. The results arising from this study provide new insights into blueberry wine production, by which treatment with MP maintain the color and ACNs contents, and improve the taste of blueberry wine.

Preparation and characterization of yeast cell wall beta-glucan encapsulated humic acid nanoparticles as an enhanced aflatoxin B1 binder

This study aimed to assess the effect of encapsulating humic acid inside yeast cell walls (YCW) to detoxify AFB₁ in in vitro gastrointestinal models. Glucan Mannan Lipid Particles (GMLPs) from Saccharomyces cerevisiae cell walls showed the highest AFB₁ adsorption in simulated gastric fluid (SGF) after 10 min, and in simulated intestinal fluid (SIF) after 1 h. GMLPs are hollow 3-4 micron porous microspheres that provide an efficient system for the synthesis and encapsulation of AFB₁-absorbing nanoparticles (NPs). Humic acid nanoparticles (HA-NPs) were synthesized within the GMLP cavity by complexation with ferric chloride. Encapsulating HA-NPs in GMLPs increased HA-NP stability in SIF. The hybrid GMLP HA-NP formulation synergistically enhanced AFB₁ binding compared to individual GMLP and HA components in SGF and in SIF. Cytotoxicity on a murine macrophage cell line demonstrated that GMLP HA-NP-AFB₁ complexes were stable in both SGF and SIF, detoxified AFB₁ and are suitable for in vivo testing.

Mitigation potential of distillery sludge against ochratoxin A induced immunological alterations in broiler chicks

Ochratoxin A (OTA) is a potent mycotoxin injurious to poultry health and an alarming factor for poultry industry while distillery sludge (DS) is a waste product of molasses based industries rich in proteins and certain essential vitamins and other nutrients. The present study was done to estimate the immunological alterations induced by OTA in broiler chicks and amelioration of these alterations by dietary supplementation of DS. For this purpose, 480 one-day old broiler chicks procured from a local hatchery, were divided into sixteen equal groups and were given different combinations of OTA (150, 300 and 1000 µg/kg feed) and DS (5, 10 and 20 g/kg feed). Parameters studied were antibodies response to sheep red blood cells (SRBCs), lymphoproliferative response to PHA-P and phagocytic index as studied by carbon clearance assay. The results of this study showed that feeding DS with 150 and 300 µg/kg OTA ameliorated OTA induced alterations, but this amelioration was partial when 1000 µg/kg OTA was used along with DS. From this study it could be concluded that DS has beneficial effects in birds suffering from ochratoxicosis. However, the proper level of DS to produce such mitigation against specific level of OTA is yet to be determined.

Effect of dietary macronutrients on aflatoxicosis: a mini-review

Aflatoxin is a toxin produced by Aspergillus species of fungi. The main route of aflatoxin exposure is through the diet. Indeed, long-term aflatoxin exposure is linked to the development of hepatocellular carcinoma (HCC). Aflatoxin causes aflatoxicosis, which can be affected by several factors and is prevalent in many developing Asian and African countries. This mini-review discusses the effects of carbohydrate, fat and protein on aflatoxicosis based on findings from animal and human studies. It was found that high carbohydrate intake enhanced aflatoxicosis occurrence, while low ingestion of carbohydrate with caloric restriction slowed the symptoms associated with aflatoxicosis. Additionally, diets with low protein content worsened the symptoms related to HCC due to aflatoxin exposure. Nevertheless, a study reported that a high-protein diet favored detoxification of aflatoxin in vivo. There were also conflicting results on the influence of dietary fat, as high ingestion of fat enhanced aflatoxicosis development as compared with a low-fat diet. Moreover, the type of fat also plays a significant role in influencing aflatoxin toxicity. In regard to food safety, understanding the influence of macronutrients toward the progression of aflatoxicosis can improve preventive measures against human and animal exposure to aflatoxin. © 2017 Society of Chemical Industry.

Aflatoxins and Saccharomyces cerevisiae: yeast modulates the intestinal effect of aflatoxins, while aflatoxin B1 influences yeast ultrastructure

The gastrointestinal tract (GIT) is the main site where absorption of food components takes place and the first system coming into contact with mycotoxins of dietary origin. The aim of this work was to study the effect of probiotic Saccharomyces cerevisiae RC016 on intestinal villi of rats exposed to aflatoxins for 60 days. Moreover, the effect of in vitro aflatoxin B1 (AFB1) exposure on yeast cell ultrastructure was evaluated. Six treatments were applied (n=6) to inbred male Wistar rats: (1) uncontaminated feed control (F); (2) yeast control; (3) F + 40 μg/kg AFB1 + 20 μg/kg aflatoxin G1 (AFG1); (4) F + 100 μg/kg AFB1 + 50 μg/kg AFG1; (5) F + 40 μg/kg AFB1 + 20 μg/kg AFG1 + daily oral dose 108 viable S. cerevisiae cells; and (6) F + 100 μg/kg AFB1 + 50 μg/kg AFG1 + daily oral dose 108 viable S. cerevisiae cells. Morphometric measurements (villus length and width, crypt depth, quantification of goblet cells) were assessed using image analysis. S. cerevisiae RC016 cells were exposed to 20 μg/ml of AFB1 in intestinal solutions or in phosphate buffered saline and cells processed for transmission electron microscopy and high resolution light microscopy studies. Dietary exposure to the yeast did not induce significant differences in villus width but increased villus length and crypt depth. Aflatoxin-contaminated diets induced an increase in villus length, width and crypt depth and a significant decrease in the number of goblet cells which were improved by the addition of S. cerevisiae RC016. A significant increase in the yeast cell diameter was observed when RC016 was exposed to aflatoxins, suggesting this as an advantage since a larger cell would be able to adsorb mycotoxins more efficiently. The ability of this strain to act as probiotic and aflatoxin binder makes it a candidate for the formulation of new additives to improve animal performance.

Patulin adsorption of a superior microorganism strain with low flavour-affection of kiwi fruit juice

The aim of this study was to isolate a microbial strain with higher patulin adsorption capability and lower flavour-affection on kiwi fruit juice, and study patulin adsorption behaviour effects on cell morphology and adsorption kinetics. Electronic-nose and physicochemical analysis methods were combined to evaluate the flavour and quality of treated kiwi fruit juice. The results showed that yeasts had a good performance on biomass, patulin adsorption and flavour maintenance. Besides, patulin adsorption behaviour and kinetic study of yeast strain N-10 was investigated, the results showed that patulin adsorption capability was influenced by cell morphology, its adsorption behaviour followed pseudo-first-order reaction kinetics, and equilibrium experiments fit the Langmuir isotherm model. The investigation revealed that patulin adsorption is a spontaneous endothermic physic-sorption behaviour. During adsorption, patulin moved from the liquid to the adsorbent surface and the capability of adsorbents was associated with their cell surface morphology. This study provides a basis for the selection of strains with improved patulin adsorption from kiwi fruit juice and provides the experimental foundation and theoretical basis for future studies of patulin adsorption in fruit juice, it has great potential application for the control of patulin in the juice processing industry.

Effect of Yeast Cell Morphology, Cell Wall Physical Structure and Chemical Composition on Patulin Adsorption

The capability of yeast to adsorb patulin in fruit juice can aid in substantially reducing the patulin toxic effect on human health. This study aimed to investigate the capability of yeast cell morphology and cell wall internal structure and composition to adsorb patulin. To compare different yeast cell morphologies, cell wall internal structure and composition, scanning electron microscope, transmission electron microscope and ion chromatography were used. The results indicated that patulin adsorption capability of yeast was influenced by cell surface areas, volume, and cell wall thickness, as well as 1,3-β-glucan content. Among these factors, cell wall thickness and 1,3-β-glucan content serve significant functions. The investigation revealed that patulin adsorption capability was mainly affected by the three-dimensional network structure of the cell wall composed of 1,3-β-glucan. Finally, patulin adsorption in commercial kiwi fruit juice was investigated, and the results indicated that yeast cells could adsorb patulin from commercial kiwi fruit juice efficiently. This study can potentially simulate in vitro cell walls to enhance patulin adsorption capability and successfully apply to fruit juice industry.

Saccharomyces cerevisiae cell wall components as tools for ochratoxin a decontamination

The aim of this study was to evaluate the usefulness of Saccharomyces cerevisiae cell wall preparations in the adsorption of ochratoxin A (OTA). The study involved the use of a brewer’s yeast cell wall devoid of protein substances, glucans obtained by water and alkaline extraction, a glucan commercially available as a dietary supplement for animals and, additionally, dried brewer’s yeast for comparison. Fourier Transform Infrared (FTIR) analysis of the obtained preparations showed bands characteristic for glucans in the resulting spectra. The yeast cell wall preparation, water-extracted glucan and the commercial glucan bound the highest amount of ochratoxin A, above 55% of the initial concentration, and the alkaline-extracted glucan adsorbed the lowest amount of this toxin. It has been shown that adsorption is most effective at a close-to-neutral pH, while being considerably limited in alkaline conditions.

In vitro aflatoxin B1 binding capacity by two Enterococcus faecium strains isolated from healthy dog faeces

AIM

This study evaluated the binding capacity of aflatoxin B1 (AFB1 ) by two Enterococcus faecium strains (MF4 and GJ40) isolated from faeces from healthy dogs.

MATERIALS AND METHODS

The binding assay was performed using 50 and 100 ppb of AFB1 analysing the effects of the viability, incubation time and pH on AFB1 binding. Binding stability was determined by washing three times the bacteria-AFB1 complexes with phosphate buffer saline.

RESULTS

Both GJ40 and MF4 strains have the ability to remove AFB1 from aqueous solution. Viable cells were slightly more effective in AFB1 binding than nonviable ones for both strains. Enterococcus faeciumGJ40 removes 24-27% and 17-24%, and Ent. faeciumMF4 removes 36-42% and 27-32% of AFB1 (50 and 100 ppb, respectively) throughout a 48 h incubation period. In general, the removal of AFB1 was highest at pH 7.00 for both strains. The stability of the bacteria-AFB1 complex formed was found to be high (up to 50% of AFB1 remained bounded in bacterial cell after three washes with phosphate buffered saline).

CONCLUSION

The Ent. faecium strains assayed are capable of removing AFB1 under different conditions in vitro.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first AFB1 binding assay performed with Ent. faecium strains isolated from dog faeces, being an interesting strategy for AFB1 decontamination of pet food.

The effect of Leiber Beta-S (1,3-1,6-β-D-glucan) on the phagocytic activity and oxidative metabolism of peripheral blood granulocytes and monocytes in calves

The effect of the Leiber Beta-S (1,3-1,6-β-D-glucan) dietary supplement on the phagocytic activity (Phagotest) and oxidative metabolism (Phagoburst) of peripheral blood granulocytes and monocytes in calves was determined by flow cytometry. Fourteen animals were divided into two groups: a control group without dietary supplementation and an experimental group administered 50 mg/kg body weight/day of 1,3-1,6-β-D-glucan for 60 days. At the beginning of the experiment (day 0) and on days 15, 30 and 60, blood was sampled from the jugular vein to determine and compare immunological indicators. Leiber Beta-S significantly influenced (P ≤ 0.05, P ≤ 0.01, P ≤ 0.001) the percentages of phagocytic granulocytes (days 15 and 30) and monocytes (days 15, 30 and 60), and the percentage of bacteria engulfed by granulocytes (days 15 and 30) and monocytes (day 30). Leiber Beta-S increased the percentage of cells generating a respiratory burst in the population of granulocytes stimulated with fMLP (N-formyl-met-leu-phe) (day 15), PMA (4-phorbol-12-β-myristate-13-acetate) and Escherichia coli bacteria (days 15 and 30), and in the population of monocytes stimulated with fMLP (day 30), PMA (days 30 and 60) and E. coli (days 15, 30 and 60). The analyzed supplement increased mean fluorescence intensity in granulocytes stimulated with E. coli and fMLP (days 15 and 30) and PMA (days 30 and 60) as well as in monocytes stimulated with PMA, E. coli and fMLP (day 60). The findings of this study contribute to a better understanding of the effects of Leiber Beta-S on phagocytosis in calves, which have not been investigated to date.

Effects of β-glucan on some environmental toxins: An overview

BACKGROUND

Beta-glucans are naturally occurring polysaccharides and constituents of the cell wall of certain pathogenic bacteria and fungi. They have proven healing and immunostimulating properties, linked to enhanced macrophage and natural killer cell function which likely involves specific interaction with several cell surface receptors, such as lactosylceramide, selected scavenger receptors, and dectin-1 (betaGR). In particular, glucan reduces the immunosuppressive effects of a number of agents including chemo therapy and radiation. More recent studies suggest a positive function for glucan in the immunosuppression caused by toxic agents in the environment.

AIM

An overview of the effects of glucan on the mycotoxin, aflotoxin and other environmental toxins (mercury-thimerosal, depleted uranium).

CONCLUSION

Glucan is effective as a natural immunomodulator and could be used as an inexpensive solution to reducing the adverse effects of some environmental toxins.

Detoxification of mycotoxins by probiotic preparation for broiler chickens

Biological decontamination of mycotoxins using microorganisms is one of the well known strategies for the management of mycotoxins in foods and feeds. Among the different potential decontaminating microorganisms,Saccharomyces cerevisiae and lactic acid bacteria represent unique groups, which are widely used in food fermentation and preservation. The aim of this study was to determine the influence of spontaneous fermentation with the use of probiotic bacteria and yeast (Lactobacillus paracasei/casei ŁOCK 0920,L. brevis ŁOCK 0944,L. plantarum ŁOCK 0945,Saccharomyces cerevisiae ŁOCK 0142), on reduction of sum of aflatoxines (B1, B2, G1, G2) and ochratoxin A concentration during fermentation and the microflora pattern during fermentaton. The probiotic bacteria and yeast applied creates a starter culture for flour fermentation that has a stable feature of detoxication of aflatoxines and especially ochratoxin A.

Anthocyanins and their variation in red wines. II. Anthocyanin derived pigments and their color evolution

Originating in the grapes, anthocyanins and their derivatives are the crucial pigments responsible for the red wine color. During wine maturation and aging, the concentration of monomeric anthocyanins declines constantly, while numerous more complex and stable anthocyanin derived pigments are formed, mainly including pyranoanthocyanins, polymeric anthocyanins produced from condensation between anthocyanin and/or flavan-3-ols directly or mediated by aldehydes. Correspondingly, their structural modifications result in a characteristic variation of color, from purple-red color in young red wines to brick-red hue of the aged. Because of the extreme complexity of chemical compounds involved, many investigations have been made using model solutions of know composition rather than wine. Thus, there is a large amount of research still required to obtain an overall perspective of the anthocyanin composition and its change with time in red wines. Future findings may well greatly revise our current interpretation of the color in red wines. This paper summarizes the most recent advances in the studies of the anthocyanins derived pigments in red wines, as well as their color evolution.

Yeast cell based feed additives: studies on aflatoxin B₁ and zearalenone

Thirty commercially available yeast cell wall products and two reference bentonites were tested for their ability to bind aflatoxin B(1) (AFB1) and zearalenone (ZON) in buffer solutions at pH 3 and pH 6.5 as well as in real gastric juice. For most products, the binding efficacy of AFB1 correlated with the ash content, which was between 2.6 and 89%, and constituted the inorganic non-volatile components, such as mineral clays, of the samples. Samples with smectite as the main ash component showed the highest binding efficacy; yet, a correlation with the content of mannanooligosaccharides (MOS) and β-glucans from yeast cell walls was not observed. Products containing >30% ash showed AFB1 adsorption values >90% at least in one of the investigated media whereas most products with <10% ash did not exceed adsorption rates of 20%. In the case of ZON, adsorption efficiency ranged between 10 and 60%. It tended to be lowest for products with MOS and β-glucan contents <10% and greatest for products with MOS and β-glucan contents >50%. However, there was no general correlation between the adsorption of ZON and the concentration of MOS and β-glucans. Different products of one brand sold in different countries were observed to bind AFB1 to different degrees, which was explained by the difference in ash contents and mineral composition. In the case of ZON, differences in adsorption between products of the same brand were less pronounced.

Microbial strategies to control aflatoxins in food and feed

Aflatoxins are a group of toxic and carcinogenic fungal metabolites. They are commonly found in cereals, nuts and animal feeds and create a significant threat to the food industry and animal production. Several strategies have been developed to avoid or reduce harmful effects of aflatoxins since the 1960s. However, prevention of aflatoxin contamination pre/post harvest or during storage has not been satisfactory and control strategies such as physical removing and chemical inactivating used in food commodities have their deficiencies, which limit their large scale application. It is expected that progress in the control of aflatoxin contamination will depend on the introduction of technologies for specific, efficient and environmentally sound detoxification. The utilisation of biological detoxification agents, such as microorganisms and/or their enzymatic products to detoxify aflatoxins in contaminated food and feed can be a choice of such technology. To date, many of the microbial strategies have only showed reduced concentration of aflatoxins and the structure and toxicity of the detoxified products are unclear. More attention should be paid to the detoxification reactions, the structure of biotransformed products and the enzymes responsible for the detoxification. In this article, microbial strategies for aflatoxin control such as microbial binding and microbial biotransformation are reviewed.

Beneficial effects of probiotic and food borne yeasts on human health

Besides being important in the fermentation of foods and beverages, yeasts have shown numerous beneficial effects on human health. Among these, probiotic effects are the most well known health effects including prevention and treatment of intestinal diseases and immunomodulatory effects. Other beneficial functions of yeasts are improvement of bioavailability of minerals through the hydrolysis of phytate, folate biofortification and detoxification of mycotoxins due to surface binding to the yeast cell wall.

Effect of commercial mannoprotein addition on polysaccharide, polyphenolic, and color composition in red wines

Commercially available mannoprotein preparations were tested in Tempranillo winemaking to determine their influence on polysaccharide, polyphenolic, and color composition. No effect was found in the content of grape arabinogalactans, homogalacturonans, and type II rhamnogalacturonans. In contrast, mannoprotein-treated samples showed considerably higher values of high-molecular-weight mannoproteins (bMP) than controls from the beginning of alcoholic fermentation, although these differences diminished as vinification progressed. The bMP decrease observed in the mannoprotein-treated samples coincided with a substantial reduction in their proanthocyanidin content and wine stable color, suggesting a precipitation of the coaggregates mannoprotein-tannin and mannoprotein-pigment. Contrary to what is widely described, these results revealed that at the studied conditions, mannoproteins did not act as stabilizing colloids. Mannoprotein addition did not modify the content and composition of either monomeric anthocyanins or other monomeric phenolics, and it did not affect monomeric anthocyanin color.

New perspectives in safety and quality enhancement of wine through selection of yeasts based on the parietal adsorption activity

The present article aims to review research papers that focus on the parietal adsorption activity of wine yeast and on its contribution to the enhancement of wine safety and quality. There is a great diversity among yeasts for their parietal adsorption activity: the outermost layer of the cell wall has a chemical composition that notably varies from yeast to yeast. Parietal mannoproteins can contain phosphate, pyruvate, or glucuronic acid, which impart negative charges, modifying the electrostatic and ionic interactions with wine components. The following could give a good reason to propose a specific selection of wine yeasts based on their parietal adsorption activity to improve wine safety and quality: (a) ochratoxin A content of wines is greatly reduced by expressly selected yeasts, sequestering the toxin during winemaking; (b) yeast influences concentration and composition of phenolic compounds in wine, above all by adsorbing them on cell wall; (c) among grape pigments, anthocyanins, in particular, may be adsorbed by yeast cell wall; and (d) yeast can also interact with wine colour producing anthocyanin-beta-d-glucosidase, pyruvic acid, and acetaldehyde or releasing mannoproteins and different polysaccharides. Genomic strategies could also be used to obtain a further enhancement of the adsorption/non-adsorption activity of wine yeasts. Based on winemaking requirements and on parietal adsorption activity, a specific selection of yeasts might be performed: (a) to protect wine colour during red winemaking, (b) to remove residual wine colour during white winemaking, (c) to selectively remove ochratoxin A, and (d) to protect phenolic compounds responsible for antioxidant activity.

Enological functions of parietal yeast mannoproteins

Parietal yeast mannoproteins play a very important role in the overall vinification process. Their production and release, both during winemaking and aging on lees, depends on the specific yeast strain and the nutritional conditions. The following enological functions of parietal yeast mannoproteins have been described: (a) adsorption of ochratoxin A; (b) combination with phenolic compounds; (c) increased growth of malolactic bacteria; (d) inhibition of tartrate salt crystallization; (e) interaction with flor wines; (f) prevention of haze; (g) reinforcement of aromatic components; (h) wine enrichment during aging on fine lees; (i) yeast flocculation and autolysis in sparkling wines. Further discoveries related to their enological functions are foreseeable. Yeast-derived mannoproteins may well induce chemical, sensorial and health benefits, thus greatly improving wine quality.

Antioxidant enzymes stimulation in Aspergillus parasiticus by Lentinula edodes inhibits aflatoxin production

Biosynthesis of aflatoxins, toxic metabolites produced by Aspergillus parasiticus, is correlated to the fungal oxidative stress and cell ageing. In this paper, the mechanism underlying the aflatoxin-inhibiting effect of the Lentinula edodes culture filtrates was studied by analysing their anti-oxidant activity and beta-glucan content. Mushroom beta-glucans are pharmacologically active compounds stimulating anti-oxidant responses in animal cells. L. edodes lyophilised filtrates stimulate A. parasiticus anti-oxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase) and aflatoxin inhibition was better correlated with beta-glucan content than with anti-oxidant activity of the filtrates. RT-PCR analyses on treated mycelia showed a delay in the activation of aflR, and norA, genes of aflatoxin cluster and a synchronous activation of hsf2-like, a homologue of a yeast transcription factor involved in oxidative stress responses. The first evidence of hsf2-like in A. parasiticus and its activation during aflatoxin biosynthesis is reported. L. edodes filtrates could play a role as external stimulus affecting the anti-oxidant status in the fungal cell that, in turn, leads to aflatoxin inhibition. In the fungal cell, beta-glucans present in the filtrates could stimulate the activation of transcription factors related to anti-oxidant response and anti-oxidant enzyme activity with a contemporaneous delay of aflatoxin genes transcription, which led to a marked reduction of aflatoxin production. This research suggests new perspectives to set suitable strategies against aflatoxins and L. edodes could be considered a promising tool.