NOVELTY - Production of fatty acid lower alkyl esters by transesterification of triglycerides or fatty acid esters with 1-6C aliphatic alcohols, involves in a first reactor source of carbohydrates is subjected to fermentation to provide broth mainly containing aqueous aliphatic 1-6C alcohol; in a second reactor triglyceride and/or ester of fatty acid with higher alcohol is placed together with biocatalyst capable to effect transesterification reaction; and the aqueous aliphatic alcohol is transferred into the second reactor to effect the transesterification reaction in two-phase system.    USE - For production of fatty acid lower alkyl esters useful as a fuel or fuel additive, for food and feed products, cosmetic applications or as chemical intermediates; for food and feed applications (claimed). Also useful as biodiesel that is used as a substitute for liquid petroleum gas or as a adjuvant for conventional fuels.    ADVANTAGE - The energy input for the producing the alkyl esters is significantly decreased, mainly by using the water-based fermentation broth directly as an alcohol source for the transesterification. The process avoids any energy-consuming procedure to separate or even reduce the water content in ethanol obtained from fermentation to make a transesterification possible, that provides high conversion and selectivity, although conducted under aqueous conditions. The process represents a closed circle, since also the by-products like glycerol or its derivatives can be used, in particular as feed for growing the alcohol-producing biocatalysts. Since, all starting materials are obtained from renewal resources, the process represents a contribution to sustainable production of industrial products.    DETAILED DESCRIPTION - Production of fatty acid lower alkyl esters of formula R1CO-OR2 (I) by transesterification of triglycerides or fatty acid esters with 1-6C aliphatic alcohols, involves in a first reactor a source of carbohydrates is subjected to fermentation to provide a broth mainly consisting of an aqueous aliphatic 1-6C alcohol; in a second reactor a triglyceride and/or an ester of a fatty acid with an higher alcohol is placed together with a biocatalyst capable to effect a transesterification reaction; and the aqueous aliphatic 1-6C alcohol obtained from the first reactor is transferred into the second reactor to effect the transesterification reaction in a two-phase system.    R1CO=linear or branched 6-22C acyl radical having 0-6 double bonds;    R2=linear or branched 1-6C alkyl radical.