This Invention Patent (IP) concerns the use of the recipe liquid from the alkaline pre-treatment of agricultural residues or agro-industrial products, also known as liqueur, more specifically from cob corn, repaired by different compounds among which can be highlighted xyloses, arabinoses, glucose, cellobiose, hemicelluloses, lignin and micronutrients, as a culture medium, therefore being considered as an important source of carbon, micro and macronutrients to be used in the process fermentative, preferably using bacteria of the genus Xanthomonas sp., in the production of xanthan gum, which has wide application in the industry chemical, petrochemical, pharmaceutical and food industries.