Research Article: The effect of temperature and different carbon and nitrogen sources on the growth and fatty acid profile of a newly isolated microorganism Aurantiochytrium sp. strain SHY

Thraustochytrids have received a great deal of attention in recent years for producing a significant amount of omega-۳ fatty acids. However, their commercial and sustainable production from microalgae sources faces technical and economic limitations. In this study, the effect of temperature and different carbon and nitrogen sources in YEP calture on the growth and fatty acids profile in a newly isolated strain of Aurantiochytrium sp. SHY has been conducted. Glucose produced more biomass, but galactose was more suitable for lipid formation. Galactose promoted the highest production of fatty acids (۳۶.۴%), but the ratio of docosahexaenoic acid to fatty acids was ۱۹.۰۵% which was less than glycerol. With an increased glucose concentration, EPA is considerably higher and DHA is only slightly increased. This is the first study that has been carried out on this new isolate wherein a mixed carbon source was used in the culture media and the results showed the microorganism’s preferences for carbohydrate consumption is in the following pattern: glucose > galactose > fructose> sucrose. The meat extract was the most suitable nitrogen source for biomass development (۷ g L-۱), but the maximum DHA to fatty acids ratio (۲۵%) was achieved when the microorganism consumed monosodium glutamate as a nitrogen source. The strain produced more biomass at ۲۵°C, and lowering the temperature achieved a higher DHA formation. The results of this study show that if this strain is going to introduce as a good potential candidate for food industries and aquaculture, it needs more study in bioreactor that’s going on.

Keywords:

Fatty acids , Mangrove forest , Nitrogen sources , Persian Gulf , Temperature