Protein increase and lysine production by a Paecilomyces variotii strain grown on two-phase olive mill waste.

Two-phase olive-mill waste, the so-called "ecological", has been treated with a Paecilomyces variotii isolate in solid state fermentation experiments. The growth of the microorganism was estimated by measuring the production of carbon dioxide, using gas chromatography. A 46% increase of the protein content was achieved at the fermented product, after molasses addition at the initial mixture. The amino acid profile of the produced protein, as far as the essential amino acids are concerned, was significantly improved, resulting in a product that has the potential to be used as animal feed. Furthermore, it contains lysine, one of the essential amino acids that did not exist at the original product and is produced during fermentation. This is the first report on solid state fermentation of the two-phase olive mill waste (TPOMW) as a substrate, using a Paecilomyces variotii strain.