Simultaneous production of xylooligosaccharides and antioxidant compounds from sugarcane bagasse via enzymatic hydrolysis

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Advances in industrial biotechnology offer potential opportunities for economic utilization of agroindustrial residues such as sugarcane bagasse, which is the major by-product of the sugarcane industry. Due to its abundant availability and despite the complex chemical composition, it can be considered an ideal substrate for microbial processes for the production of value-added products. In the present study we evaluated the enzymatic production of xylooligosaccharides (XOS) and antioxidant compounds from sugarcane bagasse using XynZ from Clostridium thermocellum, a naturally chimeric enzyme comprising activities of xylanase and feruloyl esterase along with a carbohydrate binding module (CBM6). In order to reveal the biotechnological potential of XynZ, the XOS released after enzymatic hydrolysis using different substrates were characterized by capillary electrophoresis and quantified by high performance anion exchange chromatography. In parallel, the antioxidant capacity related to the release of phenolic compounds was also determined. The results indicated noteworthy differences regarding the amount of XOS and antioxidant phenolic compounds produced, as well as the XOS profile, functions of the pre-treatment method employed. The ability of XynZ to simultaneously produce xylooligosaccharides, natural probiotics, phenolic compounds and antioxidant molecules from natural substrates such as sugarcane bagasse demonstrated the biotechnological potential of this enzyme. Production of value-added products from agro-industrial residues is of great interest not only for advancement in the biofuel field, but also for pharmaceutical and food industries. (C) 2013 Elsevier B.V. All rights reserved.52770775Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)CNPq [474022/2011-4, 310177/2011-1, 142685/2010-0]FAPESP [2008/58037-9, 2011/14200-6, 2012/18859-5, 2013/03061-0

Characterization of a Hexameric Exo-Acting GH51 alpha-l-Arabinofuranosidase from the Mesophilic Bacillus subtilis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)alpha-l-Arabinofuranosidases (alpha-l-Abfases, EC 3.2.1.55) display a broad specificity against distinct glycosyl moieties in branched hemicellulose and recent studies have demonstrated their synergistic use with cellulases and xylanases for biotechnological processes involving plant biomass degradation. In this study, we examined the structural organization of the arabinofuranosidase (GH51 family) from the mesophilic Bacillus subtilis (AbfA) and its implications on function and stability. The recombinant AbfA showed to be active over a broad temperature range with the maximum activity between 35 and 50 A degrees C, which is desirable for industrial applications. Functional studies demonstrated that AbfA preferentially cleaves debranched or linear arabinan and is an exo-acting enzyme producing arabinose from arabinoheptaose. The enzyme has a canonical circular dichroism spectrum of alpha/beta proteins and exhibits a hexameric quaternary structure in solution, as expected for GH51 members. Thermal denaturation experiments indicated a melting temperature of 53.5 A degrees C, which is in agreement with the temperature-activity curves. The mechanisms associated with the unfolding process were investigated through molecular dynamics simulations evidencing an important contribution of the quaternary arrangement in the stabilization of the beta-sandwich accessory domain and other regions involved in the formation of the catalytic interface of hexameric Abfases belonging to GH51 family.553260267Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [2008/58037-9, 10/51890-8, 2011/14200-6, 2011/13242-7, 2010/11499-1]CNPq [133394/2011-5, 475022/2011-4, 310177/2011-1, 2011/17658-3, 140420/2009-6