Currently, different origin waste oils have been used mostly as animal feed, raw material for soap makers, and feed stock for fatty acid production. The existent patents and commercial processes to make fatty acids from waste oils always refers to hydrolysis and acidification steps using strong acids such as sulphuric or hydrochloridic acids, producing a mixture of fatty acids, inorganic salts, water, and other small components such as glycerine or phospholipids. Waste technical fats can provide a raw material basis for the production of surfactants. This amount of waste oil will serve as raw material for obtaining bio-surfactant and ester oils by biotechnological processes.This project Bio-SURFEST will develop two biotechnological processes at semi-industrial scale in order to produce two different classes of bio-products, bio-surfactants and ester oils (non useful for biodiesel production). Bio-surfactants will be produced by fermentative process and ester oils will be produced by enzymatic catalysis. Both biotechnological methods will use as raw materials or feedstock fry waste oil or technical fats.The main goal of the project Bio-SURFEST is to obtain high-value compounds such as bio-surfactants and ester oils from waste oils or technical fats, which represent a low value residue from a great variety of industries like hotels, restaurants, vegetable oil industry, biodiesel producers, etc. The aim of the present project is to determine suitable technical and economical production methods in order to obtain biosurfactants and other bio-products of high added value. Bio-SURFEST is focusing on the biotechnological optimisation of bio-products synthesis, using techniques such as fermentation and enzymatic catalysis. Using this approach, tailor-made bio-products will be obtained, purified and finally tested for their use in different applications.