Optimizing heterotrophic production of Chlorella sorokiniana SU-9 proteins potentially used as a sustainable protein substitute in aquafeed. (February 2023)

• Record Type: Journal Article
• Authors: Chen, Chun-Yen; Lu, Jhih-Ci; Chang, Yu-Han; Chen, Jih-Heng; Nagarajan, Dillirani; Lee, Duu-Jong; Chang, Jo-Shu
• Is Part Of: Bioresource technology. Volume 370(2023)
• Publication Date: 2023-02
• Subjects: Microalgal proteins -- Heterotrophic growth -- Aquafeed -- Amino acid profile -- Chlorella sorokiniana; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2022.128538
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: Chlorella sorokiniana SU-9 is capable of heterotrophic growth and protein accumulation. Glucose and sodium nitrate are the optimal sources of carbon and nitrogen, respectively. Maximal protein productivity reached of SU-9 reached 382 ± 36 mg/ L/d. Nitrogen source concentration influenced the amino acid composition of algal biomass. SU-9 proteins are rich in the essential amino acids arginine, lysine and cysteine. Abstract: Alternative protein sources for the reduction/replacement of fish meal in aqua-feeds are in urgent demand. Microalgae are considered sustainable protein sources for aquaculture due to their high-quality proteins with a complete profile of essential amino acids. This study examined the heterotrophic production of proteins from Chlorella sorokiniana SU-9. Culture parameters for maximal biomass and protein production are as follows: glucose – 10 g/L glucose, sodium nitrate – 1.5 g/L, and iron – 46 μM iron in BG-11 medium. Under optimal conditions, biomass content, protein content and protein productivity of SU-9 reached 4.14 ± 0.20 g/L, 403 ± 33 mg/g and 382 ± 36 mg/L/d, respectively. The protein profile of Chlorella sorokiniana SU-9 is comparable to fishmeal and soybean meal. The essential amino acids arginine, lysine and cysteine, along with glutamine and glutamate, were high. The production cost of SU-9 can be significantly reduced under heterotrophic cultivation conditions, making it a potential protein substitute in aquafeed.