Perspectives on optimizing microalgae cultivation: Harnessing dissolved CO2 and lactose for sustainable and cost-efficient protein production

• Published in: Journal of agriculture and food research 2024-12, Vol.18, p.101387, Article 101387
• Main Authors: Chen, Sunni, Zhu, Honglin, Radican, Emily, Wang, Xinhao, D'Amico, Dennis J., Xiao, Zhenlei, Luo, Yangchao
• Format: Article
• Language: English
• ISSN: 2666-1543; 2666-1543
• DOI: 10.1016/j.jafr.2024.101387

Microalgae, known for their land-sparing cultivation and remarkable photosynthetic efficiency, play a crucial role in advancing sustainable development goals. This study explored the use of cost-effective inorganic carbon (the ionic form of CO2) and organic carbon sources (lactose, a primary sugar in whey wastewater) to support the growth of Chlorellasorokiniana UTEX 1230, and improved protein content through nitrogen supply optimization. NaHCO3 proved to be more effective than Na2CO3, resulting in a 3.4-fold increase in biomass concentration, with an initial 5 mM HCO3‾ concentration compared to the basal medium. Further addition of 0.75 % lactose led to a 4.05-fold increase in biomass concentration, with the maximum specific growth rate at 1.28/d, maximum biomass concentration at 695.88 mg/L, and maximum biomass productivity at 250.91 mg/L/d. Nitrogen supplementation greatly increased protein concentration from 16.41 % (250 mg/L NaNO3) to 52.95 % (1000 mg/L NaNO3). These results support the potential for utilizing whey wastewater bioremediation to produce high-value protein via microalgal cultivation. [Display omitted] •Lactose effectively supported the mixotrophic growth of C. sorokiniana UTEX 1230.•NaHCO3could serve as an inorganic carbon source for C. sorokiniana UTEX 1230.•Nitrogen input increased the protein level of C. sorokiniana UTEX 1230 over 50 %.•The strain showed the potential to utilize whey wastewater for protein production.