Simultaneous saccharification and cofermentation of peracetic acid-pretreated biomass

Previous work in our laboratories has demonstrated the effectiveness of per acetic acid for improving enzymatic digestibility of lignocellulosic materi als. The use of dilute alkali solutions as a pre-pretreatment prior to pera cetic acid lignin oxidation increased carbohydrate hydrolysis yields in a s ynergistic as opposed to additive manner. Deacetylation of xylan is easily achieved using dilute alkali solutions under mild conditions. In this artic le, we evaluate the effectiveness of peracetic acid combined with an alkali ne pre-pretreatment through simultaneous saccharification and cofermentatio n (SSCF) of pretreated hybrid poplar wood and sugar cane bagasse. Respectiv e ethanol yields of 92.8 and 91.9% of theoretical are achieved using 6% NaO H/15% peracetic acid-pretreated substrates and recombinant Zymomonas mobili s CP4/pZB5. Reduction of acetyl groups of the lignocellulosic materials is demonstrated following alkaline pre-pretreatments. Such processing may be h elpful in reducing peracetic acid requirements. The influence of deacetylat ion is more significant in combined pretreatments using lower peracetic aci d loadings.