Abstract

The search for biotechnological alternatives for the use of residuals generated in the agro-industrial processing of coffee is a current problem. This study evaluated the biotransformation of the liquid residual of the humid coffee benefit using the yeast Kluyveromyces marxianus CCEBI 2011. It was demonstrated that this strain is able to effectively use the reducing and neutral sugars in 24 h, for a yield of 40% in the production of alcohol. Pectin oligomers were obtained with an average size between 5.4 and 5.8 units of anhydrogalacturonic acid, with potential biological activity. In the fermented residuals, a decrease of more than 30% in the concentration of caffeine was observed. The pectinolytic yeast K. marxianus CCEBI 2011 significantly reduces the content of soluble proteins in the liquid residual. The results indicate that the residuals of the coffee benefit are viable substrate to be used by means of alcoholic fermentation in the presence of the pectinolitic yeast K. marxianus CCEBI 2011, reducing its environmental impact and propitiating alternatives for their better use in the agricultural sector.

Key words: Kluyveromyces marxianus, pectinolitic yeast, coffee residuals.