부산대학교 도서관

• Successful application of ozonation to reduce the lignocellulosic crystallinity. • Rice husks chemical treatment lead to high fermentable sugar yields. • Succinoglycan sustainable production by R. radiobacter fermentation. • All over multivariate design employed to optimize the experiments. Rice husk (RH) was submitted to ozonation followed by pressurized acid hydrolysis with the aim of reducing the lignocellulosic recalcitrance and freeing the fermentable monosaccharides from cellulose and hemicellulose. The hydrolysate was then detoxified and used as a fermentative substrate for the production of succinoglycan biopolymer, which is an exopolysaccharide. The use of pH 7.0, and 25% RH (w v−1) solution, and the effects of ozonization for 60 min (1.5 g h-1 de O 3), made the lignocellulosic matrix more susceptible to subsequent pressurized acid hydrolysis (2.5% H 2 SO 4 w v−1 , 45 min treatment, 145 °C), and produced up to 16.1 g sugars L-1. Detoxification with activated carbon (4.0% v v -1, 60 min, 80 °C) reduced the inhibition and made the broth more fermentable. The Rhizobium radiobacter (LMG196 and ATCC4720) then produced 69.0 g succinoglycan L-1 under optimized conditions. Once extracted (91.2% purity) and characterized (FT-IR, NMR, GPC and SEM), this led to a new set of results that were better than those found in the literature, since they included the exploitation of the left-over biomass for the production of a valuable exopolysaccharide (41.6 g 100 g-1 RH). The unconstrained multivariate optimization allied to the RH ozonation strategy, followed by pressurized acid hydrolysis, gave rise to promising yields, which confirms the technical viability and the innovative feature of succinoglycan production. [ABSTRACT FROM AUTHOR]