Enzymatic hydrolysis followed by alcoholic fermentation of prickly pears (Opuntia ficus-indica L.) cladodes and fruits using Saccharomyces cerevisiae E1A

Mr. John Karalis Dr. Dimitrios Arapoglou Dr. Giorgos Markou Mr. Christos Eliopoulos Prof. Seraphim Papanikolaou
Session: Biowaste
CEST ID: 790 Poster
The cultivation and production of biomass of prickly pear is of particular interest due to the fact that it can be grown in arid areas, producing higher amounts of biomass with lower inputs (water, fertilizers etc.) compared to other crops. The present study examines whether enzyme hydrolysis is capable to increase the amount of reducing sugars available to S. cerevisiae E1A strain to be used during alcoholic fermentation. Enzymatic hydrolysis was performed using the commercial enzymes Termamyl and Celluclast applied at various concentrations of dried cladodes and of dried fruit and added juice from discarded fresh prickly pears in order to enrich the quantity of sugars into the solution. The substrate used in the bioreactor experiment consisted of 100 g/L of dried cladodes with 40 g/L of dried fruit, which after the addition of the juice resulted in the synthesis of a liquid growth medium containing 48 g/L of sugars. The microorganism finally managed to produce a significant amount of endopolysaccharides inside the yeast biomass (22.12% w/w) while biomass (DCW) production was of 4.35 g/L. Ethanol at 21.54 g/L with a yield of ethanol produced per unit of sugar consumed YEtOH/S was equal to 0.49 g EtOH / g of substrate.