Microbial CAZymes and their industrial applications

GHIO, SILVINA; PICCINNI, FLORENCIA; ONTAÑON, ORNELLA MAILÉN; GARRIDO, MERCEDES M; CAMPOS, ELEONORA

Buenos Aires

Simposio; 3rd Argentinian Symposium on Glycobiology; 2019

Lignocellulosic biomass is formed by a complex network of cellulose, hemicellulose and lignin that provides plants with strength and resistance and also results in recalcitrance to degradation. As it is a highly abundant renewable resource, its use to obtain biofuels and bioproducts is being strongly studied. In order to deconstruct the structural polysaccharides of biomass it is necessary the concerted action of multiple enzymes, collectively referred to as CAZymes. The main enzymes are endo and exo-acting glucanases (EC 3.2.1.4, EC 3.2.1.91/ EC 3.2.1.176), xylanases (EC 3.2.1.8), β-glucosidases (EC 3.2.1.21) and β-xylosidases (EC 3.2.1.37) as well as enzymes with oxidative activity (LPMOs). We have studied the microbial enzymatic mechanisms of hydrolysis of polysaccharides in order to develop enzymes for agro-industrial applications. By characterizing the secreted CAZome of cellulolytic bacteria, we have identified the key enzymes involved in cellulose and hemicellulose utilization. In particular we have focused on the enzymatic systems of Cellulomonas sp. B6 and Paenibacillus sp. A59, as well as enzymes from the fungi Pycnoporus sanguineus. The analysis of the activity profile and mechanism of action of individual enzymes, expressed as recombinants, has allowed as an insight into their contribution to biomass degradation. We have applied thermally stable xylanases in high solids processes to obtain bioethanol from residual biomass.