NOVELTY - Obtaining fatty acid involves pulverizing dried bamboo leaves to obtain its powder. The obtained bamboo powder is then passed through 80 mesh sieves to obtain fine bamboo powder. The obtained fine bamboo powder is then subjected to enzymatic hydrolysis with acid solution and lignocellulase to obtain lignocellulosic hydrolyzates. The obtained lignocellulosic hydrolyzates are refrigerated at certain conditions to obtain fresh or thawed lignocellulosic hydrolyzates, which are then mixed with water to adjust its total carbohydrate concentration.    USE - Method for obtaining fatty acid by recovery of an ionic liquid from hydrolysate of lignocellulosic biomass (claimed).    ADVANTAGE - The method efficiently utilizes hydrolysate of lignocellulosic biomass as renewable biomass resources, and thus able to obtain fatty acid in an environmental-friendly manner. The method is also capable of solving the problem of chemical synthesis of fatty acids during petrochemical resource shortages.    DETAILED DESCRIPTION - Obtaining fatty acid involves pulverizing dried bamboo leaves to obtain its powder. The obtained bamboo powder is then passed through 80 mesh sieves to obtain fine bamboo powder. The obtained fine bamboo powder is then subjected to enzymatic hydrolysis with acid solution and lignocellulase to obtain lignocellulosic hydrolyzates. The obtained lignocellulosic hydrolyzates are refrigerated at certain conditions to obtain fresh or thawed lignocellulosic hydrolyzates, which are then mixed with water to adjust its total carbohydrate concentration. Seed medium is then prepared, where Escherichia coli is then inoculated to the prepared seed medium, and then kept in an incubator for 16-20 hours. The certain amount of activated Escherichia coli cells i.e. 5-10% inoculum is inoculated into the fermentation medium, and then kept in an incubator at 30-37 degrees C hours for 24-72 hours to obtain fatty acids in the fermentation broth as the finished product. Fermentation medium is then prepared by dissolving nitrogen source and inorganic salts with pH buffers. The seed medium apprises 10-20 g/L peptones, 5-10 g/L yeast powder, and 5-10 g/L sodium chloride.