Optimization of Submerged Fermentation of β-phenylethanol Production by Kluyveromyces marxious with Response Surface Methodology
Abstract: The cultivation conditions for β-Phenylethanol (β-PE) production using Kluyveromyces marxious AS 2.1440 were optimized statistically in shake flask experiments. Based on a single factor experiment design, we implemented the two-level Plackett–Burman (PB) design with 11 variables to screen related factors that significantly influence β-PE production. Inoculum, speed and L-Phenylalanine concentration were identified as the most important significant factors. Subsequently, the path of steepest ascent was used to approach the optimal region of the above three factors. Finally, Response surface methodology based on the Center Composite Design and response surface analysis was applied to determine these factors’ optimal levels and their mutual interactions for β-PE production. The predicted results showed that 930 mg/l of β-PE production was obtained after a 48-h fermentation period, with optimal condition of L-Phe (4.0g/L), inoculum (5.7%), and speed (163 rpm) in the flask fermentations. The optimized conditions allowed β-PE yield to be increased from 402 mg/l to 926 mg/l after verification experiments test.
Keywords: β-phenylethanol; Kluyveromyces marxious AS2.1440; Plackett-Burman design; response surface method; optimization
