No abstract

Alkalinea nd biological lignocellulosep re-treatments are commonly used to enhance enzymatic hydrolysis and improve ethanol production. In this study, 13 CC PMAS NMR spectroscopy was used to describec hanges in sugarcane bagasse( SCB) pretreated with NaOH, Ca(OH) 2 andw ith Pycnoporus sanguineus. Changes in the contentso fa lkyl C, Carboxyl C, Aromatic C (tertiary, quaternary and p-hydroxyphenyl C), O-alkyl C, amino acids, ergosterol and chitin, as well as in the crystallinity index of cellulose were observed. Through am ultivariate analysis, relations betweenc hanges in the chemical compositiono fS CB and enzymatic hydrolysis were established. P. sanguineus promotes better lignin decay,g lucoser elease and hydrolysis yields than chemical pre-treatments, and increases the amount of amino acids and ergosterol in SCB, while NaOH increases the cellulose crystallinity index. The hydrolysates weref ermented with Saccharomyces cerevisiae for 96 h, and analysed through HPLC. The initial compositionofthe hydrolysates [mg.ml À1 ]and biomass production (cells.ml À1 )w ere then relatedt ot he ethanol production and fermentation yields. We found that ethanol production and fermentation yields were negatively correlated with cell growth in Saccharomyces,b ut positively correlated with glucose consumption in the P. sanguineus pretreatment. We conclude that the biological pre-treatmentusing P. sanguineus in the conditions hereby described, has a potentialtoincreaseethanol productivity.