Utilization of Cheese Whey and Cellulosic Biomass for Production of Ethanol by Selected Fungi Strain from Brazilian Savannas

Abstract

The objective of this study was to produce ethanol using cheese whey, cellulosic biomass and crude enzymatic extract from wild-type fungi isolated from Brazilian Savanna (Cerrado). A total of 64 samples of material (flowers, fruit and soil) were collected and cellulase production by isolated fungal strains was evaluated using enzymatic activity index methodology.
The selected fungi was used to produce ethanol in a two step process: a) crude enzyme complex was produced by solid-state fermentation followed by the extraction of the enzyme complex from the fermented biomass using milk whey and hydrolyzed milk whey (0.1 % H₂SO₄, 0.5 atm, 30 min); b) enzymatic extract was used (Simultaneous Saccharification and Fermentation) to produce ethanol from Saccharomyces cerevisiae and steam-exploded sugarcane bagasse.
According to the results obtained, the use of cheese whey was effective in improving the ethanol yield. The use of cheese whey to extract enzyme complex increased the ethanol production in 20.4 % compared to a control test using water in place of cheese whey and the use of hydrolyzed cheese whey increased ethanol production in 55.1 % compared to water extraction. The best result for ethanol fermentation (17.9 g/L of ethanol) was obtained after 48 h of fermentation.