Valorization of Xylan in Residual Plant Biomass through Enzymatic Degradation

CAMPOS, ELEONORA

Queretaro

Congreso; VIII Congreso de Fisicoquímica, Estructura y Diseño de Proteínas; 2023

Sociedad Mexicana de Bioquimica y Red de Estructura, Función y Evolución de Preoteínas

The valorization of the hemicellulose fraction of plant biomass plays a critical role in enhancing the sustainability of lignocellulosic biorefineries. Aerobic bacteria employ a complex array of enzymes to degrade plant cell wall polysaccharides. In this study, we focus on the extracellular proteome of two Gram-positive strains, Cellulomonas sp. B6 and Paenibacillus xylanivorans, isolated from soil. Extensive investigations were conducted to understand the culture conditions that lead to high secretion of xylanases, allowing the use of a cost-effective enzymatic extract. Furthermore, we identified the enzymes most likely responsible for this activity and expressed them in recombinant hosts to purify and characterize their enzymatic activity as well as to identify structural determinants. Additionally, we explored the specificity and synergy of xylanases in conjunction with enzymes that remove xylan decorations. I will present the results on CsXyn10A, an endoxylanase with high activity, and the synergy with CsAbf62A, an α-arabinofuranosidase, as well as CsAgu67A, an α-glucuronidase. The results obtained from these investigations enabled us to design specific enzymatic cocktails for the treatment of different lignocellulosic biomass feedstocks to produce fermentable xylose, as well as to obtain a range of substituted and unsubstituted xylo-oligosaccharides, with prebiotic potential.