Aproveitamento de resíduos agroindustriais lignocelulósicos para produção enzimática de oligossacarídeos visando a obtenção de agente prebiótico para a saúde humana

Author(s)

Patrícia Felix Ávila

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia de Alimentos
• Defense date: 2022-02-25

Examining board members

Rosana Goldbeck; Raquel Cristine Kuhn; Patrícia Poletto; Eliana Setsuko Kamimura; Fátima Aparecida de Almeida Costa

• Advisor: Rosana Goldbeck

Abstract

Lignocellulosic materials represent a source of raw material that is under-explored in biotechnological processes, since a large surplus of waste from the industrial processing of agricultural raw materials is generated annually. Thus, the production of xylooligosaccharides (XOS) from the enzymatic hydrolysis of xylan present in hemicellulose from these residues, as well as celloligosaccharides (COS) from cellulose present an intelligent and sustainable alternative for their valorization. This study aimed to produce oligosaccharides (XOS and COS) from enzymatic hydrolysis of lignocellulosic agroindustrial residues (sugarcane straw and coffee husk) as a source of arabinoxylan and cellulose, in order to evaluate their prebiotic potential in human health. Different strategies were used to improve the integrated alkaline process for fractionation of arabinoxylan and cellulose from the prior delignified lignocellulosic materials which provided yields and efficiency of arabinoxylan extraction around 40.35% and 82.32%, respectively with insignificant values of lignin content. In a second step, central rotating composite rotating designs (CCRD) were used to develop mixtures of enzymes for the production of XOS and COS from the extracted arabinoxylans and the cellulose-rich products obtained, respectively. Efficient enzyme mixtures were developed with endoxylanase (GH11), ?-l-arabinofuranosidase (GH51), and feruloyl esterase (CE1), providing high concentrations of XOS reaching values of up to 511.5 (mg).(gsubstrate)-1. As well as using endo-1,4-?-D-glucanase (GH12), exo-1,4-?-D-glucanase (GH5) and feruloyl esterase (CE1) for the production of COS reaching values maximized around 63.56 (mg).(g substrate)-1. As a second strategy to increase the COS production and and investigate the possible effects of inhibiting by cellobiose, a study employing adsorbed endo-1,4-?-D-glucanase (GH12) to substrates in multiple stages of enzymatic hydrolysis was performed, where it was possible to reach values around 85.43 (mg). (g substrate) -1. As the last step of the process, a fractionation process of the oligosaccharides was carried out using nanofiltration membranes in series in order to assess the prebiotic potential of the previous fractions. In vitro steps showed that oligosaccharides developed exhibited resistance to hydrolysis by enzymes of the gastro-intestinal system. As well as that probiotic cultures of Lactobacillus and Bifidobacterium stream growth on media containing XOS and COS as the sole carbon source. The microorganisms consumed preferentially xylobiose (X2) and xylotriosis (X3) and in relation to the media containing COS they consumed mostly as fractions cellobiose (C2) and cellotriosis (C3). Thus, the results found that both biomasses use are potential sources for the production of prebiotic oligosaccharides and that their fractionation into fractions of lower molecular weight contributes to increase the prebiotic potential of both XOS and COS as from both biomass (AU)

• FAPESP's process: 17/24503-2 - Use of agroindustrial lignocellulosic waste for the production of oligosaccharides aiming at obtaining a prebiotic agent in human health
• Grantee: Patricia Felix Avila
• Support Opportunities: Scholarships in Brazil - Doctorate