Effect of pre-treatment on chemical composition, structure and enzymatic hydrolysis sugar cane straw

The sugarcane straw is a by-product of the sugar and alcohol industries and is available in abundance in Brazil (around 7Mi t/year) being an important source of sugars for cellulose ethanol obtainment. This work aimed to study the effect of pre-treatment of sugar cane straw (dried leaves) with 2 min of microwave radiation in presence of glycerol diluted in water, sulphuric acid and sodium hydroxide on the chemical composition, fiber structure and on subsequent enzyme hydrolysis with enzyme produced by M. thermophila M.7.7. Infrared spectra, thermal analysis (TGA, DTG, DSC,) and optical and transmission electron microscopy showed that acid and alkaline pre-treatments presented action mainly on deconstruction of lignin and hemicellulose polymers preserving the cellulose. The chemical analysis of solid fraction also indicate lignin and the hemicellulose decrease and the analysis of liquid fraction corroborated this results, since showed high phenol and pentose content. In the hydrolysis assays, the highest yield of reducing sugars from treated material confirm that the treatment improve the enzyme saccharification.