Fresh Ulva lactuca alcoholic fermentation products and yields

Abstract

The optimization of the ethanol yield obtained by alcoholic fermentation of fresh Ulva lactuca in the presence of cellulase and Saccharomyces cerevisiae yeast was performed. Three main factors affecting the process were considered: the solid-to-liquid ratio (S), cellulase-to-algal biomass ratio (R), expressed as cellulase units (U) per gram of dry matter (DM), and the alcoholic fermentation temperature (t). The optimal parameters were: S=1/24 g/g, R=16 U/ g DM and t=35°C, when alcohol yield was 0.34 g/100 g fresh alga, within the range of other authors’ experimental data. Over 200 compounds were identified in the distillate from the fermentation broth, recommending Ulva lactuca as a sustainable source of drugs, intermediates for biosyntheses and biomaterials. The yield of these compounds was 5.92 g/100 g fresh alga, in the same conditions. The yields of ethanol (0.013-0.023 g/g DM) and volatile compounds (0.199-0.398 g/g DM) were predicted depending on the process factors using regression equations obtained by ANOVA analysis of experimental data.