Enhanced growth and lipid productivity by living Chlorella sorokiniana immobilized in Ca-alginate beads

Abstract

The bottleneck for the production of biofuels from microalgae consists on costly harvesting processes and low lipid production, immobilization technology could play a part on making the production of biofuels more feasible. The aim of this study was to evaluate the effect of alginate immobilization on the growth and lipid productivity of the microalgae Chlorella sorokiniana, so far, the main focus of immobilization technology has been its use for wastewater treatment and nutrient removal from effluents. The microalgae Chlorella sorokiniana was cultured in both free and immobilized forms under optimal autotrophic growth conditions. Microalgae were immobilized in calcium alginate beads generated by mixing algal cells with a sodium alginate solution, followed by extrusion into a CaCl2 solution. The results obtained in this study showed that the growth of the microalgae immobilized in alginate beads, was enhanced and achieved a dry cell weight 1.4-fold higher than that of a free cell culture, a higher light transmittance was also achieved in the alginate immobilized culture, and the lipid productivity was increased from 54.21 ± 2.48 mg/L/d in the free cell culture to 82.22 ± 8.48 mg/L/d in the immobilized culture. These results demonstrate the effectiveness of immobilization technology for promoting growth and lipid productivity in the microalgae Chlorella sorokiniana.

Calcium alginate elastic capsules for microalgal cultivation

“…For these reasons, calcium alginate hydrogel beads have been investigated thoroughly for microalgal cell cultivation-related applications such as agricultural uses, biofuel, chemical production, food supplements, and wastewater treatment. [17][18][19][20] For instance, de Jesus et al successfully utilized calcium alginate hydrogel beads containing immobilized Desmodesmus subspicatus microalgal strain for the removal of potassium, carbon, and nitrogen from sugarcane vinasse. Detailed analysis demonstrated the stability of the hydrogel beads throughout the cultivation experiments, leading to a signicant removal of potassium, carbon, and nitrogen (up to 28%, 38%, and 27% respectively) due to microalgae metabolism.…”

Comparison of Immobilized and Free Amyloglucosidase Process in Glucose SyrupsProduction from White Sorghum Starch

“…The use of alginate can provide several advantages including broad availability; cost effectiveness, good biocompatibility without toxicity and good hydrogel-forming ability upon the addition of divalent cations such as Ca 2 + . [25,26] For these benefits, the purpose of this research was to evaluate the performance of calcium alginate beads as a support material for Rhizopus mold amyloglucosidase entrapment and their subsequent utilization in the hydrolysis of white sorghum starch. It involves the determination of optimum conditions of immobilization and glucose syrups production.…”