TECHNOLOGY FOCUS - BIOLOGY - Preferred Components: The biocatalysts show a high acyl transferase activity particularly in the presence of water and no or very low activity for the hydrolyzation of ester bonds. The biocatalysts are selected from species consisting of Candida, Kluyveromyces, Geotrichum, Fusarium, Aeromonas, Debaryomyces, Arxula, Zygoascus, Emercilla, Aspergillus, Malassezia, Gibberella, Kurzmanomyces, Ustillago, Nocardia, Cordyceps, Mycobacterium, Rhodococcus, Saccharopolyspora, Burkholderia, Corynebacterium, Saccharopolyspora, Pseudomonas, Streptomyces and Pichia. The transesterification biocatalysts are selected from micro-organisms consisting of Aeromonas aerophila, Arxula adeninivorans, Aspergillus fumigatus, Aspergillus niger, Burkholderia cenocepacia, Candida albicans, Candida antarctica Trychosporon oryzae, Pseudozyma antarctica, Candida cylindracea, Candida glabrata, Candida maltosa, Candida parapsilosis, Candida rugosa, Candida tropicalis, Candida viswanathii, Chromobacterium viscosum, Cordyceps bassania, Corynebacterium diphtheriae, Debaryomyces hansenii, Emercilla nidulans, Fusarium oxysporum, Fusarium solani, Fusarium sporotrichioides, Geotrichum candidum, Gibberella zeae, Issatchenkia orientalis (Candida krusei), Kluyveromyces marxianus (C. kefyr, C. pseudotropicalis), Kurzmanomyces sp., Malassezia pachydermatis, Mucor javanicus, Mycobacterium tuberculosis, Mycobacterium bovis, Mycobacterium avium, Nocardia farcinica, Penicilium camenberti Pichia guilliermondii (Candida guilliermondii), Porcine pancreas, Pseudomonas fluorescens, Rhizomucor miehei, Rhizopus javanicus, Rhizopus oryzae, Rhodococcus sp., Saccharopolyspora spinosa, Saccharopolyspora pogona, Streptomyces coelicolor, Thermomyces lanugenosus, Ustillago maydis and/or Zygoascus hellenicus (preferably Candida parapsilosis or Candida albicans). The transesterification enzymes are either free enzymes or enzymes immobilized on suitable carriers. The enzymes are used in an amount of 0.001-5 wt.% calculated on the total amount of triglycerides and/or fatty acid esters. The enzymes showing a high esterification activity are added to the transesterification process to convert free fatty acids, which may have been formed from hydrolysis into the desired lower alkyl esters.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: The fermentation takes place in the presence of yeasts or a bacteria, where the yeast has a food grade quality. The fermentation is conducted at 20-80degrees C. The fermentation broth comprises 1-6C aliphatic alcohol (5-30 wt.%) and water (70-95 wt.%). The concentration of the aqueous lower alcohol from fermentation in the second reactor is adjusted to a level, which is always higher than the critical concentration limit where hydrolysis starts as a side reaction. The lower alcohol concentration is adjusted to 2-20 wt.% calculated on the water phase. The transesterification is conducted at 10-80degrees C. The aqueous phase is separated from the organic phase. The glycerol or higher alcohols from the aqueous phase are reobtained either by distillation or membrane separation. The glycerol obtained from the aqueous phase is used as a feed for growing the yeasts or bacteria used in the fermentation step. Preferred Components: The aliphatic alcohol is ethanol. The source of carbohydrates is a sugar or a starch, inulin, cellulose or lignocellulose. The triglycerides are selected from palm oil, palm kernel oil, coconut oil, olive oil, rape seed oil, sunflower oil, safflor oil, soy oil, line seed oil, fish oil and/or beef or pork tallow. The triglycerides show an acid value of 0-10. The esters of fatty acids and short chain alcohols are of formula R1CO-OR2 (I). EXAMPLE - A fermentation was performed by using the method as as described in Alfenore et al. (Appl. Microbiol. Biotechnol. 63:537-542, 2004) in a fermentor at 30degrees C, pH 5 regulated with NH3 (14 vol.%/vol.%). Aeration was set and stirring adjusted to keep dissolved oxygen to 20% of saturation. The fermentation was performed with an exponential feeding of biotin based on the growth profile (total biotin concentration added 32 micrograms 1-1). The fermentor was supplied with a sterile glucose feed (700 g/l) using a peristaltic pump. Fermentation was started with a glucose concentration of 100 g 1-1 and inoculated with a Saccharomyces cerevisiae (1 g/l) strain previously grown on the same medium. When residual glucose concentration was lower than 20 g 1-1, glucose feeding was carried out to restore a glucose concentration of 100 g 1-1 or 50 g 1-1 respectively when ethanol concentration was lower or higher than 90 g 1-1. When ethanol concentration in the fermentor reached 110 g/l, the enzyme bioreactor was continuously fed with the fermentation liquid phase, and cells were recycled into the fermentor. The aqueous phase from the enzyme bioreactor, containing remaining ethanol (100 g/l) and glycerol from transesterification was also continuously recycled into the fermentor. The enzyme bioreactor had no specific pH or temperature control and worked in the conditions set by the fermentor (pH 5, 30degrees C). The bioreactor contained immobilized lipase/acyltranferase (3500 U) (-350 mg) from C. parapsilosis per liter of fermentation broth (one U is the amount of enzyme that catalyzes the release of 1 micronsol ethyl ester/min in the presence ethanol (2M) and rapeseed oil at 30degrees C, pH 5). In these conditions, biomass concentration was 20 g/l (dry weight) and produced ethanol/l/hour (10 g) when ethanol concentration was 110 g/l. The ethanol produced was converted into ethyl ester (67 g/l/h) by enzymatic transesterification of rapeseed oil. After 15 hours of transesterification, the fermentor contained ethanol (110 g/l) and glycerol (100 g/l) in the supernatant. The total amount of ester produced by transesterification was 1 kg/l fermentation broth. The main production step was then terminated by stopping the glucose feed and the enzyme bioreactor was switched to another fermentor in production. After glucose depletion by fermentation, the yeast in the original fermentor started oxidizing ethanol, glycerol and free fatty acids (from oil or released in the enzyme bioreactor by residual hydrolytic side-reaction), leading to a final production of fodder yeast biomass (140 g/l) after complete oxidation of substrates. The whole process converted, for fermentation medium (1 l), glucose (550 g) and rapeseed oil (950 g) into ethyl ester (1000 g) and yeast biomass (140 g).