Screening of exopolysaccharide production and evaluation of biofilm formation capacity in aspergillus strains isolated from stored peanut seeds

The preservation and conservation of foodstuffs are steps that ensure better food safety. Indeed, in our countries, the storage of fruits, vegetables and seeds maintain temperature and humidity conditions favorable to the emergence of several microorganisms including molds. These moulds develop mechanisms that allow them to adapt to the support and the food stored. In order to assess the food safety of stored peanut seeds, peanut samples were analyzed for molds in their microbiological quality. Four strains of moulds of the genus Aspergillus isolated were analysed in their capacity of production of exopolysaccharides and the formation of biofilms. The production of exopolysaccharides was detected by colorimetric methods by culturing the moulds on Sabouraud medium with Congo Red added. Screening of biofilms was carried out on microplate wells by staining with crystal violet of the culture. Quantification of biofilm production was done by following the kinetics by spectrophotometric method. The results obtained from the phenotypic screening showed exopolysaccharide production in all strains. The kinetics of biofilm formation showed a better quantity in the sucrose supplemented medium. The adaptive mechanisms developed by molds in food can be the cause of the formation of toxic compounds that constitute a public health problem, hence the need to take $preventive measures for the conditions of food preservation and storage.