High-solid enzymatic hydrolysis of sugarcane bagasse and ethanol production in repeated batch process using column reactors.

Unlabelled: Alkaline sulfite pretreated sugarcane bagasse was enzymatically hydrolyzed in a packed-bed column reactor and a bubble column reactor was evaluated to produce ethanol from the hydrolysate. Initial solid loadings of 9-16% were used in column reactor in the hydrolysis step, and the use of lower value (9%) resulted in 41 g L of glucose in the hydrolysate, corresponding to 87% of cellulose hydrolysis yield. This yield was reduced to 65% for a solid loading of 16%, corresponding to a glucose concentration of 54 g L.

Hydrated fractions of cellulosics probed by infrared spectroscopy coupled with dynamics of deuterium exchange.

This article presents a novel method to selectively probe the non-crystalline, hydrated fractions of cellulosic biomass. The method is based on time-resolved infrared spectra analyzed to provide information on spectral and dynamical features of deuterium exchange (OH → OD) in D2O atmosphere. We assign deuterium exchange spectral regions (700-3800 cm(-1)) and explore changes due to relative humidity, different cellulosic samples, and infrared polarization.

Tissue-specific cell wall hydration in sugarcane stalks.

Plant cell walls contain water, especially under biological and wet processing conditions. The present work characterizes this water in tissues of sugarcane stalks. Environmental scanning electron microscopy shows tissue deformation upon drying.

Enzymatic digestion of alkaline-sulfite pretreated sugar cane bagasse and its correlation with the chemical and structural changes occurring during the pretreatment step.

Sugar cane bagasse is recalcitrant to enzymatic digestion, which hinders the efficient conversion of its polysaccharides into fermentable sugars. Alkaline-sulfite pretreatment was used to overcome the sugar cane bagasse recalcitrance. Chemical and structural changes that occurred during the pretreatment were correlated with the efficiency of the enzymatic digestion of the polysaccharides.

Enzymatic hydrolysis of chemithermomechanically pretreated sugarcane bagasse and samples with reduced initial lignin content.

Chemithermomechanical (CTM) processing was used to pretreat sugarcane bagasse with the aim of increasing cell wall accessibility to hydrolytic enzymes. Yields of the pretreated samples were in the range of 75-94%. Disk refining and alkaline-CTM and alkaline/sulfite-CTM pretreatments yielded pretreated materials with 21.

Actin immobilization on chitin for purifying myosin II: A laboratory exercise that integrates concepts of molecular cell biology and protein chemistry.

This article presents our experience on teaching biochemical sciences through an innovative approach that integrates concepts of molecular cell biology and protein chemistry. This original laboratory exercise is based on the preparation of an affinity chromatography column containing F-actin molecules immobilized on chitin particles for purifying skeletal myosin II. It favors the active learning of protein extraction and purification, the learning of concepts such as muscle contraction, cytoskeleton structure, and its importance for the living cell.