Anais CBFic - Volume 1 - 2018

Sociedade Brasileira de Ficologia - SBFic

Publicado em 26/11/2018

Volume 1 - 2019

Título do Trabalho

ACID HIDROLYSIS OF THE MACROALGAE SOLIERIA FILIFORMIS FOR CHEMICALS AND FERMENTABLE CARBOHYDRATES PRODUCTION

Autores

EDNA MARIA SILVA CORDEIRO, LETíCIA HOLANDA FREITAS, INGRID HOLANDA FREITAS, TANIMARA OLIVEIRA MOREIRA, RENATO CARRHá LEITãO, MARJORY LIMA HOLANDA ARAúJO, NORMA MARIA BARROS BENEVIDES

Modalidade

Resumo

Área Temática

3 BIOTECNOLOGIA E INOVAçõES

Data de Publicação

26/11/2018

País da Publicação

Brasil

Idioma da Publicação

Português

Página do Trabalho

http://sbfic.org.br/anais_show/94

ISSN

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Palavras-Chave

algae, monosaccharides, organic acids

Resumo

The biotechnological conversion of biomass to fuels and chemicals has been the subject of scientific studies due to the increasing environmental concern on the use of fossil resources. In this context, algae stand out as promising sources for such purposes because they are lignin-free and have high levels of easily hydrolyzable carbohydrates. The objective of this work was to obtain an optimized condition for acid hydrolysis process of the macroalgae Solieria filiformis, evaluating the effects of acid concentration, reaction time and temperature on the production of fermentable carbohydrates. Two rotational central composite designs (RCCD) were carried out with the algae, using sulfuric acid solution set at 1:10 (m/v). Initially, the RCCD was performed to assess the effect of the temperature (100-200 ºC), time (15-120 min) and sulfuric acid concentration (0.1-1.0 M). The first results show that the reaction time did not significantly affect the acid hydrolysis process. A second RCCD was carried out, with reaction time set at 15 min, but extending the temperature range (70-130 ºC), as well as sulfuric acid concentration range (0.1-1.0 M). The response variables of both DCCRs were the carbohydrates concentrations (cellobiose, arabinose, galactose and glucose), determined by high performance liquid chromatography. The algae polysaccharides conversion efficiency to monosaccharides was also evaluated. The optimized condition was observed when sulfuric acid 0.55 M, 100 °C and 67 min were used to produce 26.0 g/L of fermentable monosaccharides (19.0 g/L galactose, 5.0 g/L glucose and 2.0 g/L arabinose), leading to a conversion efficiency of 54%. A more severe hydrolysis conditions (150 ºC, sulfuric acid 0.55 M and 67 min) resulted in production of acetic acid (59.84 g/L) and formic acid (9.86 g/L), which is undesirable for further fermentation. The second experiment set resulted in a higher monosaccharides production (21.0 g/L galactose, 5.2 g/L glucose and 2.4 g/L arabinose) and conversion efficiency (67%), which was found at 100 °C, sulfuric acid 1 M, and 15 min. Reduced concentrations of acetic acid (1.76 g/L), formic acid (10.90 g/L), HMF (2.30 g/L) and furfural (0.62g/L) were also observed. Therefore, the macroalgae S. filiformis presented easily hydrolyzable structural polysaccharides composition, in which only the sulfuric acid concentration and temperature showed significant effects on the production of fermentable carbohydrates.