The effect of ultrasonication on protein content and recovery of protein extract from Chlorella vulgaris

Abstract An upward trend in animal protein consumption presents potential concerns regarding the environmental sustainability of livestock systems. An alternative protein source is Chlorella vulgaris , which has a protein content of 42-58% of its dry-weight biomass. However, the rigid cell wall in C. vulgaris can hinder protein extraction; therefore, methods such as ultrasonication are necessary to disrupt the cell wall. This study aims to test the effectiveness of ultrasonication in protein extraction. Sample solubilization and precipitation were performed at a pH of 11 and 4, respectively. The results showed that ultrasonication significantly increased the protein content (dry basis) and protein recovery. The extracted material without ultrasonication had a protein content of 29.05 ± 1.87% and a protein recovery of 0.11% ± 0.00%, whereas with ultrasonication, these values were 85.18 ± 10.44% and 0.32% ± 0.02%, respectively. However, the low yield necessitates further optimization and combination with other techniques to enhance mass recovery.