Towards protein production and application by using Chlorella species as circular economy

• Published in: Bioresource technology 2019-10, Vol.289, p.121625-121625, Article 121625
• Main Authors: Lai, Yu-Cheng, Chang, Chien-Hsiang, Chen, Chun-Yen, Chang, Jo-Shu, Ng, I-Son
• Format: Article
• Language: English
• Subjects: Antibacterial activity; Chlorella; Microalgal proteins; Prebiotic properties
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2019.121625

[Display omitted] •Two Chlorella were cultured in optimized medium with nutrients for highly protein production.•Protein productivity increased by 4.86 folds and 2.77 folds for C. vulgaris FSP-E and C. sorokiniana.•The highest protein production was enhanced up to 852.2 mg/L in semi-continuous operation.•Two algal proteins had 40% essential amino acids.•Chlorella proteins owned the antibacterial and prebiotic activities. In this study, productions of microalgal proteins were explored via a circular economy concept. First, production of proteins from Chlorella vulgaris FSP-E (CV) and Chlorella sorokiniana (CS) was optimized by using favorable cultivation conditions and strategies. The optimal CO2 concentration for the growth of both microalgae was 5% (v/v), while the optimal nitrogen source for CV and CS were 12 mM of NaNO3 and NH4Cl, respectively. Addition of 12 mg/L ammonium iron (III) citrate enhanced protein production. Next, semi-batch cultivation strategy was employed to achieve a protein production of 793.3 and 812.8 mg/L for CV and C S, representing a 4.86 and 2.77 fold increase, respectively, in protein productivity. The obtained microalgal proteins consist of 40% essential amino acids. The CV and CS proteins possess prebiotic activities as they enhanced the growth of Lactobacillus rhamnosus ZY by 48 and 74%, respectively, with a good antibacterial activity against predominant pathogens.