Impacto de las condiciones de cultivo sobre la estructura de la pared celular de Kluyveromyces marxianus VM004 y su influencia en la adsorción de la aflatoxina B1

Abstract The aim of this study was to determine the impact of Kluyveromyces marxianusVM004 culture conditions on the cell wall (CW) structure and its influence on aflatoxin B1 binding.The yeast was inoculated into two types of culture media: yeast extract-peptone-dextrose (YPD)broth and dried distiller’s grains with solubles (DDG). The CW was extracted from the biomassproduced in these media. AFB1 (150 ng/ml) adsorption tests using the biomass (1 × 107 cells/ml)and the CW (0.001 g) were performed at pH 2 and pH 8. Transmission electron microscopy (TEM)evaluated the CW thickness, and infrared spectroscopy (IR) determined the CW composition.Biomass production in YPD was higher than that in DDG. Cell diameter (m) and CW thickness(m) increased in the DDG medium. The CW percentage obtained in DDG was higher than that inYPD. The absorbance of carbohydrates by IR was higher in YPD. pH influenced AFB1 adsorption,which was lower at pH 8. The proportion of -glucan and chitin present in CW was higher inthe YPD medium. The IR method allowed to study the CW carbohydrate variation under theinfluence of these carbon sources. In conclusion, the culture media composition influenced the-glucan and chitin composition and consequently, AFB1 adsorption.