Effect of Primary By-Product (Nejayote) of the Nixtamalization on Fungal Growth

BACKGROUND Nejayote is an alkaline agro-industrial residue that is generated from the nixtamalization process of maize, whose chemical composition is made up of carbohydrates, fiber, and lipids that come mainly from the pericarp of the maize from which it comes. Furthermore, the presence of phenolic compounds has been detected when Nejayote comes particularly from pigmented maize. As an agro-industrial residue, Nejayote can be used as substrate for the growth of microorganisms, like fungi. METHODS Three culture media were formulated using Potato Dextrose Agar (PDA) combined with filtered Nejayote extracts from 3 types of maize (withe -NWM-, red -NRM-, and purple -NPM-) and the growth capacities of Fusarium solani , Colletotrichum orbiculare , Alternaria alternata , Botrytis cinerea , and Phytophthora capsici were measured. Also, the fungi were evaluated by macroscopic parameters like mycelial growth rate and colony morphology for 7 days. RESULTS Growth increased in all fungi strains, however, A . alternata , B. cinerea, and P. capsici showed changes in the morphology and color of the colonies, which suggests the production of secondary metabolites like pigments due to the utilization of components of Nejayote extracts as growth substrate. CONCLUSION Filtered Nejayote extracts in combination with traditional synthetic culture media, improved a growth of fungi strains. In addition, the inherent composition of Nejayote wastewater allows it utilization to promote the synthesis of secondary metabolites from fungi cultures with potential biotechnological applications Graphical Abstract