Acid hydrolysis conditions for the production of fine chemicals from Gracilaria birdiae alga biomass

• Published in: Algal research (Amsterdam) Vol. 53; p. 102139
• Main Authors: Albuquerque, José Cirlanio Sousa, Araújo, Márjory Lima Holanda, Rocha, Maria Valderez Ponte, de Souza, Bartolomeu Warlene Silva, de Castro, George Meredite Cunha, Cordeiro, Edna Maria Silva, Silva, Jouciane de Sousa, Benevides, Norma Maria Barros
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.2021
• Subjects: 5-HMF; Formic acid; Galactose; Glucose; Levulinic acid; Seaweed; Seaweed; 5-HMF; Glucose; Levulinic acid; Galactose; Formic acid
• ISSN: 2211-9264; 2211-9264
• DOI: 10.1016/j.algal.2020.102139

Gracilaria birdiae is a tropical agarophytes species of red seaweed that is rich in carbohydrates and presents a great potential for mariculture and economic use. However, it is still understudied as a potential renewable resource. In this study, the hydrolysis conditions of G. birdiae algal biomass, reaction time, and sulfuric acid concentration for obtaining monosaccharides, organic acids, and furanic compounds were optimized. Glucose and galactose concentrations were found to be more affected by algal biomass concentration, while the production of 5-hydroxymethylfurfural (5-HMF) and organic acid were most affected by sulfuric acid concentration. The most suitable conditions to produce glucose (28.56 ± 0.72 g·L−1) and galactose (108.03 ± 1.32 g·L−1) were at 121 °C, with sulfuric acid 1.3 mol·L−1, 841.59 g·L−1 of algal biomass and time of 20 min. For cellobiose (25.39 ± 0.43 g·L−1), the condition was sulfuric acid 0.6 mol·L−1, 680 g·L−1 of biomass, and 10 min. For 5-HMF (19.82 ± 0.43 g·L−1), it was sulfuric acid 0.6 mol·L−1, 680 g·L−1 of biomass and 30 min. Finally, for levulinic (38.88 ± 0.58 g·L−1) and formic acids (26.75 ± 0.54 g·L−1) and, the best conditions were sulfuric acid 2.0 mol·L−1, 680 g·L−1 of biomass and 30 min. Thus being, Gracilaria birdiae is a promising renewable resource to produce fine chemicals and fermentable compounds by optimizing its acid hydrolysis conditions. [Display omitted] •Gracilaria birdiae biomass was easily hydrolysed under acid condition•The variables affected differently the release of fine chemicals•Maximum of 28.56 g·L−1 glucose and 108.03 g·L−1 galactose were obtained•Sulfuric acid had the greatest effect on 5-hydroxymethylfurfural and organic acids•Levulinic and Formic acids are obtained with slight variations in sulfuric acid