Selection of rational parameters for the extraction of algae polysaccharides using enzymatic hydrolysis

In recent years, there has been a growing interest in the development of new polymeric, non-toxic, biodegradable materials extracted from renewable resources, such as cellulose. The aim of this work is selection of rational parameters for the extraction of algal polysaccharides (including cellulose) using enzymatic hydrolysis. Extraction of polysaccharides from algal biomass has been carried out using dilute mineral acids, alkali and water. For hydrolysis, algae thalli have been divided into parts and crushed into pieces of different sizes (5–10 cm) and dried for 15 hours in an oven at 105–106 °C to facilitate fine grinding. The dried biomass has been crushed to particle sizes of 0.1; 1.0; 5.0 and 10.0 cm. A solid load with a mass fraction of 10% is effective. The hydrolysis has been performed using the enzyme «Cellulase Ultra», which is an enzymatic preparation for the breakdown of xylans and other non-starch polysaccharides. A spectrophotometric method based on the interaction of sugars with an anthrone reagent has been used to determine sugars. The polysaccharide content in extracts isolated at 100 °C ranged from 0.77±0.09 g for red algae to 1.31±0.14 g for brown algae, depending on the extraction duration. It has been established that the following rational parameters for the enzymatic extraction of cellulose are: a sample fineness of 0.1– 0.5 cm, a temperature range of 180–200 °C, and a pressure of 1.0–1.5 MPa. The selected conditions allow for the extraction of fibers ranging from light beige to brownish in color without charring. The data obtained on the enzymatic hydrolysis of algae for the decomposition of cellulose indicate that the efficiency of this process and the composition of the resulting products depend significantly on the structural properties of the raw material, the balance and activity of the cellulase enzyme complex, and the hydrolysis methods used.