The health enhancer yeast Saccharomyces cerevisiae in two types of commercial products for animal nutrition.

The health enhancer yeast Saccharomyces cerevisiae (SC) is widely used in diets for different animals. Two main types of SC-based products are commercially available, one containing live yeasts and one containing SC fermentation by-products, which are supposedly not dependent on live yeasts for their physiological effects in vivo. Culture-based techniques were applied to study yeasts in two types of commercial products: a product containing live SC (LSC) and a SC fermentation product (SCFP). Three temperatures (25, 30 and 39°C) and two pH levels (4 and 7) were tested. The product with LSC contained an average of 1·21 × 109 colony-forming units (CFUs) of yeasts per g contents (min: 1 × 108 , max: 3 × 109 ). In contrast, the SCFP contained an average of 4·67 × 103 (min: 3 × 102 , max: 1·9 × 104 ) CFUs per g contents (c. 1 million times less than the concentration of yeasts in the product with LSC). Both temperature and pH level affected the number of CFUs but this effect differed between the two products. Biochemical tests identified the two yeasts as SC, which differed in their ability to ferment maltose (negative in the SCFP). This report encourages more research on commercial microbial strains for animal nutrition that can lead to a better understanding of their mode of action in vivo. SIGNIFICANCE AND IMPACT OF THE STUDY: Probiotics (or direct fed microbials) are increasingly popular in Animal Nutrition. Different products containing live micro-organisms or microbial-derived products are commercially available to enhance health and boost commercial traits. The characteristics of these products dictate their physiological effects and determine their potential to increase profitability from livestock. For the first time, this report presents data about the numbers and phenotype of the health enhancer Saccharomyces cerevisiae in two widely available commercial products in Animal Nutrition. These findings may be useful for scientists and producers around the globe and have the potential to open up novel venues for research.

Mycotoxins in a changing global environment--a review.

Mycotoxins are toxic metabolites produced by fungal species that commonly contaminate staple foods and feeds. They represent an unavoidable problem due to their presence in globally consumed cereals such as rice, maize and wheat. Most mycotoxins are immunosuppressive agents and some are carcinogens, hepatotoxins, nephrotoxins, and neurotoxins. Worldwide trends envision a stricter control of mycotoxins, however, the changing global environment may not be the ideal setting to control and reduce the exposure to these toxins. Although new technologies allow us to inspect the multi-mycotoxin presence in foods, new sources of exposure, gaps in knowledge of mycotoxins interactions, appearance of "emergent" mycotoxins and elucidation of consequent health effects can complicate their control even more. While humans are adapting to cope with environmental changes, such as food scarcity, decreased food quality, mycotoxin regulations, crop production and seasonality, and other climate related modifications, fungal species are also adapting and increased cases of mycotoxin adverse health effects are likely to occur in the future. To guarantee access to quality food for all, we need a way to balance global mycotoxin standards with the realistic feasibility of reaching them, considering limitations of producers and designing strategies to reduce mycotoxin exposure based on sound research.