Alcohol fermentation in olive oil extraction effluents

Abstract Eight culture-collection yeast strains of various species and five newly isolated strains were tested for both growth in olive oil extraction effluents and fermentation of the sugars in the same media. The culture-collection yeast strains did not grow in an effluent containing 2·86% sugar (w/v), 8 g/litre phenolic substances, 4·58 g/litre titratable acidity and pH 4·96, whereas the newly isolated strains of Torulopsis sp. MK-1, Saccharomyces norbensis MC-1, S. oleaceus MC-2 and S. oleaginosus grew well and fermented the sugars. In the medium mentioned above, they produced alcohol in amounts of 1·63 to 1·38%, respectively. None of the yeasts grew in an olive oil extraction effluent vacuum-concentrated to over 13–14% of dry matter. The strain of T . sp. MK-1 showed a hogher stability.