Table 1.

Examples of genetic engineering of microalgae for pharmaceutical protein production.

Microalgae Strain	Gene/Target Site	Approach	Results	References
Chlamydomonas reinhardtii	Endolysins Cpl-1 and Pal	Foreign gene expression	Total recombinant protein yield was ~1.3 mg/g algal dry weight	Stoffels et al. [23]
Chlamydomonas reinhardtii	Birch pollen allergen Bet v 1	Codon-optimized gene and stably integrated	Allergen expression with yields between 0.01 and 0.04% of TSP	Hirschl et al. [27]
Thalassiosira pseudonana	Antigen IbpA DR2	Nuclear-based expression	Increased recombinant protein by 1.2%	Davis et al. [21]
Chlamydomonas reinhardtii	HIV antigen P24	Codon-optimized	The yield of the recombinant protein increased up to 0.25% of the total cellular protein	Barahimipour et al. [28]
Chlamydomonas reinhardtii and Chlorella vulgaris	SARS-CoV-2 receptor binding domain (RBD) and basic fibroblast growth factor (bFGF)	Nuclear transformation	Up to 1.14 mg/g RBD and 1.61 ng/g FGF in C. vulgaris and 1.61 mg/g RBD and 1.025 ng/g FGF in C. reinhardtii	Malla et al. [33]
Schizochytrium sp.	Epitopes from tumor associated antigens	Cloning and ex-pression	BCB protein was expressed at levels up to 637 μg/g fresh weight	Hernández-Ramírez et al. [34]
Haematococcus pluvialis	antimicrobial peptide piscidin-4	Expression of codon-optimized	Confirmed that the antimicrobial peptide could be expressed from H. pluvialis	Wang et al. [35]
Tetraselmis subcordiformis	rt-PA	nuclear transformation	rt-PA was integrated, and the expression product was bioactive	Wu et al. [36]
Fistulifera solaris	cox gene	Cloning and ex-pression	The total content of Prostaglandins (PGs) was 1290.4 ng/g of dry cell weight	Maeda et al. [37]
Schizochytrium sp.	LTB:RAGE vaccine	Algevir system (inducible geminiviral vector)	Led to yields of up to 380 μg LTB:RAGE/g fresh weight	Ortega-Berlanga et al. [38]
Schizochytrium sp.	vaccine against Zika virus (ZIKV)	Algevir technology to express an antigenic protein	Antigen yields of up to 365 μg g−1 microalgae fresh weight	Márquez-Escobar et al. [39]
Chlamydomonas reinhardtii	Human interferon (IFN)	Cloning and ex-pression	IFN-α2a is expressed and it is functionally active as anticancer and antiviral agent	El-Ayouty et al. [40]
Chlamydomonas reinhardtii	PfCelTOS Antigen	Chloroplast expressed	Expressed recombinant PfCelTOS accumulates as a soluble, properly folded and functional protein	Shamriz et al. [41]
Chlamydomonas reinhardtii	Human growth hormone (hGH)	Codon-optimized and new vectors	0.5 mg hGH per liter of culture	Wannathong et al. [22]