ARS | Publication request: Dilute-acid pretreated sugarcane bagasse with fungal treatment and fermentable by Saccharomyces cerevisiae

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: May 5, 2011
Publication Date: May 5, 2011
Citation: Da Cruz, S.H., Salgado, G.M., Cotta, M.A. 2011. Dilute-acid pretreated sugarcane bagasse with fungal treatment and fermentable by Saccharomyces cerevisiae [abstract]. In: Proceedings of the 33rd Symposium on Biotechnology for Fuels and Chemicals, May 2-5, 2011, Seattle, Washington. Paper No. 8-32.

Technical Abstract: Recovering fermentable sugars from sugarcane bagasse requires a pretreatment followed by enzymatic saccharification. During pretreatment inhibitory compounds are often formed that impede fermenting microorganisms. Biological detoxification has been identified as a potential method to prepare biomass hydrolysates for fermentation. The aim of this study was to examine the toxicity of hydrolysates prepared from sugarcane bagasse pretreated with dilute acid on the fungi Aspergillus niger and Phanerochaete chrysosporium. Ground sugarcane bagasse mixed with 0.5% (v/v) sulfuric acid was subjected to pretreatment at 121 deg C for 15 min. The pretreated material was then inoculated with either fungus and incubated at 28 deg C for 17 d. Hydrolyzates were obtained by extracting fungal digested material with 150 mL of distilled water followed by filtration after stirring for 1 h at ambient temperature. The resulting fungal treated hydrolysates were determined to be fermentable by Saccharomyces cerevisiae. Cell concentration was maintained, cell viability was greater than 60%, and total acidity of the medium remained close to 1.0 mg acid.L-1 after 24 h fermentation of hydrolyzate obtained after cultivation with A. niger. Hydrolysate obtained from P. chrysosporium cultivation in dilute-acid pretreated bagasse did not alter the acidity of the medium which remained around 3.0 mg acid.L-1; the same as that for uninoculated bagasse pretreated with acid. The results indicate that both fungi were able to grow on bagasse pretreated with acid, with or without prior neutralization, but each culture exhibited different behavior on the hydrolysate.