Saturated and Polyunsaturated Fatty Acids Production by IAurantiochytrium limacinum/I PKU#Mn4 on IEnteromorpha/I Hydrolysate

• Published in: Marine drugs Vol. 21; no. 4
• Main Authors: He, Yaodong, Zhu, Xingyu, Ning, Yaodong, Chen, Xiaohong, Sen, Biswarup, Wang, Guangyi
• Format: Journal Article
• Language: English
• Published: MDPI AG 01.03.2023
• Subjects: Chemical properties; Environmental aspects; Fatty acids; Identification and classification; Marine algae; Production processes; China
• ISSN: 1660-3397; 1660-3397
• DOI: 10.3390/md21040198

Thraustochytrids are unicellular marine heterotrophic protists, which have recently shown a promising ability to produce omega-3 fatty acids from lignocellulosic hydrolysates and wastewaters. Here we studied the biorefinery potential of the dilute acid-pretreated marine macroalgae (Enteromorpha) in comparison with glucose via fermentation using a previously isolated thraustochytrid strain (Aurantiochytrium limacinum PKU#Mn4). The total reducing sugars in the Enteromorpha hydrolysate accounted for 43.93% of the dry cell weight (DCW). The strain was capable of producing the highest DCW (4.32 ± 0.09 g/L) and total fatty acids (TFA) content (0.65 ± 0.03 g/L) in the medium containing 100 g/L of hydrolysate. The maximum TFA yields of 0.164 ± 0.160 g/g DCW and 0.196 ± 0.010 g/g DCW were achieved at 80 g/L of hydrolysate and 40 g/L of glucose in the fermentation medium, respectively. Compositional analysis of TFA revealed the production of equivalent fractions (% TFA) of saturated and polyunsaturated fatty acids in hydrolysate or glucose medium. Furthermore, the strain yielded a much higher fraction (2.61–3.22%) of eicosapentaenoic acid (C20:5n-3) in the hydrolysate medium than that (0.25–0.49%) in the glucose medium. Overall, our findings suggest that Enteromorpha hydrolysate can be a potential natural substrate in the fermentative production of high-value fatty acids by thraustochytrids.