Optimizing heterotrophic production of Chlorella sorokiniana SU-9 proteins potentially used as a sustainable protein substitute in aquafeed

Chun-Yen Chen; Jhih-Ci Lu; Yu-Han Chang; Jih-Heng Chen; Dillirani Nagarajan; Duu-Jong Lee; Jo-Shu Chang

doi:10.1016/j.biortech.2022.128538

Optimizing heterotrophic production of Chlorella sorokiniana SU-9 proteins potentially used as a sustainable protein substitute in aquafeed

Bioresour Technol. 2023 Feb:370:128538. doi: 10.1016/j.biortech.2022.128538. Epub 2022 Dec 26.

Authors

Chun-Yen Chen¹, Jhih-Ci Lu², Yu-Han Chang², Jih-Heng Chen³, Dillirani Nagarajan⁴, Duu-Jong Lee⁵, Jo-Shu Chang⁶

Affiliations

¹ University Center for Bioscience and Biotechnology, National Cheng Kung University, Tainan, Taiwan; Research Center for Circular Economy, National Cheng Kung University, Tainan 701, Taiwan.
² Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan.
³ Research Center for Smart Sustainable Circular Economy, Tunghai University, Taichung 407, Taiwan.
⁴ Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan; Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan.
⁵ Department of Mechanical Engineering, City University of Hong Kong, Kowloon, Tang, Hong Kong.
⁶ Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan; Research Center for Smart Sustainable Circular Economy, Tunghai University, Taichung 407, Taiwan; Department of Chemical and Materials Engineering, Tunghai University, Taichung 407, Taiwan; Department of Chemical Engineering and Materials Science, Yuan Ze University, Chung-Li 32003, Taiwan. Electronic address: changjs@mail.ncku.edu.tw.

PMID: 36581231
DOI: 10.1016/j.biortech.2022.128538

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.

Keywords: Amino acid profile; Aquafeed; Chlorella sorokiniana; Heterotrophic growth; Microalgal proteins.

MeSH terms

Amino Acids, Essential / metabolism
Animals
Biomass
Chlorella* / metabolism
Glucose / metabolism
Heterotrophic Processes
Microalgae* / metabolism

Substances

Glucose
Amino Acids, Essential