Aflatoxin-Binding Saccharomyces cerevisiae RC16 Strain Improves Production Parameters In Rats Fed with Aflatoxin B1-Contaminated Feed

MARÍA L. GONZALEZ PEREYRA; AYELÉN TORRES, ; CARINA PEREYRA, ; SOFÍA N. CHULZE*, ; ANA M. DALCERO, ; LILIA R. CAVAGLIERI.

Congreso; MYCORED North America 2012; 2012

Yeast is frequently fed to livestock for its nutritional value in the form of commercially formulated additives. In previous studies, Saccharomyces cerevisiae strain RC16 isolated from pig intestine was able to in vitro bind AFB1. In this study, S. cerevisiae RC16 ability to counteract detrimental AFB1 effects in Wistar rats was evaluated. Thirty-six animals (male, 8 weeks old, similar weight) were kept in metabolic cages for 60 days. Six diet treatments (n=6) were applied: T1) control: uncontaminated feed, T2) yeast control: daily oral dose of S. cerevisiae 108 cells ml-1, T3) feed amended 40 µg kg-1 AFB1, T4) feed amended 100 µg kg-1 AFB1, T5) feed amended 40 µg kg-1 AFB1 + daily oral dose of S. cerevisiae 108 cells ml-1 and T6) feed amended 100 µg kg-1 AFB1 + daily oral dose of S. cerevisiae 108 cells ml-1. Animals were fed 30 g of feed per day and water ad libitum. Animals were weighed three (3) times a week and the total weight gain (TWG), progressive weight gain (PWG), feed efficiency (FE) and feed conversion (FC) parameters were determined. Genotoxicity was evaluated trough the rodent bone marrow micronuclei assay. Histopathological lesions were evaluated in liver tissue. Saccharomyces cerevisiae RC16 was able to improve all production parameters in animals fed 40 and 100 µg kg-1 AFB1 (P≤0.05). In T6, genotoxicity was significantly reduced compared with T3, T4 and T5 (P≤0.05). Treatments with yeasts attenuated necrotic lesions from moderate to sparse (T5) and from sparse to none (T6). The beneficial effect may be due to the adsorption of the mycotoxin by the yeast cell wall in the intestine which reduces its bioability improving animal performance. Moreover, an increment in AFB1 concentration in feces of yeast-treated rats was detected by HPLC, confirming in vivo adsorption. These results indicate a potential use of strain RC16 for the formulation of feed additives destined to livestock.