Combining Ultrasound and Microwave to Improve the Yield and Quality of Single-Cell Oil from Mortierella isabellina NTG(1-121)

In this article, to increase the extraction efficiency and quality of single-cell oil (SCO) from Mortierella isabellina NTG(1-121) (MIN) in the SCO extraction, ultrasound in combination with microwave was applied. The best extraction conditions (microwave power 400 W; microwave time 3.7 min; ultrasonic time 40.5 min; ultrasonic power 500 W; and the material to solvent ratio 1:12.3 [w/v]) were achieved at room temperature of 25 +/- 5 degrees C, using response surface methodology (RSM). Under these conditions, the extraction yield of SCO was up to 92.24% and the SCO yield was 178.13 +/- 0.17 mg g(-1) (wet cell). Compared with ultrasound-assisted extraction (UAE) and acid-heating extraction (AHE), the quality and yield of SCO obtained using the ultrasonic-assisted/microwave-assisted extraction (UMAE) were improved. The present study suggests that UMAE can be an alternative for the extraction of SCO from MIN. The oil is rich in oleic acid (ca. 43.98%), linoleic acid (ca. 11.56%), and gamma linolenic acid (ca. 11.38%), which is comparable to the fatty-acid composition of several edible oils.