Adsorption of aflatoxin B1 (AFB1) by Kasachstania bovine showing a cooperative effect that increases their efficiency

PIZZOLITTO ROMINA; ARMANDO MARIA; COMBINA MARIANA; CAVAGLIERI LILIA; DALCERO ANA; SAVANO MARIO

Huerta Grande, Córdoba

Jornada; XVII Jornadas Científicas de la Sociedad de Biología de Córdoba; 2009

Many microorganisms, mainly yeasts and lactic acid bacteria are able to eliminate mycotoxins from liquid medium. In our laboratory, we developed a model which quantifies the efficiency of the process (M x Keq) by determining the total number of sites for adsorption (M) and the equilibrium constant (Keq) involved. The purpose of this study was to evaluate the ability of yeast detoxifying Kasachstania bovine isolated from chicken feces. 107 cells ml-1 were incubated at 37 ° C with increasing concentrations of AFB1 (0.3-20 ug ml-1) for 10 min. Centrifugation at 5000 g 15 min, allowed us to determine AFB1 concentration in  supernatant by HPLC. Adsorption isotherms showed a biphasic curve whose inverse values corresponds to M and Keq. When the concentration of AFB1 in the medium exceeded 2.5 ug ml-1, M increased 6-fold and the Keq declined only 40% so that the efficiency increased by almost 4 times. The results indicate that Kasachstania bovine is potentially a very effective bioeliminator AFB1 in liquid medium, as in the presence of high concentrations of the toxin, showed a cooperative effect at the level of its cell wall that increases the number of adsorption sites and hence their efficiency.