Penambahan Glukosa sebagai Kosubstrat dan Pengaruhnya terhadap Produksi Xilitol oleh Candida guilliermondii

Abstract

Xylitol is a five-carbon sugar alcohol and used commercially in various fields. Xylitol can be produced by solid-liquid extraction from fruits and vegetables, also chemical synthesis which is expensive and energy-intensive. Therefore, an alternative inexpensive production techniques is required, one of them is using microorganism. The purposes of this research were to determine the optimum incubation time for the growth of C. guilliermondii, and xylitol production, also to determine the best ratio variation of glucose:xylose. Fermentation was carried out at 300C with shaking speed 120 rpm. Ratio variation used in this research were (glucose:xylose) 1:25, 1:12, 1:5, 1:2.5. Xylitol concentration was measured with spectrophotometer based on D-sorbitol/Dxylose Kit. The results showed the log phase of the growth of C. guilliermondii at 12-36 hour, and the optimum incubation time to obtain the highest amount of xylitol at 72 hour. The best variation ratio of glucose:xylose is 1:5 with initial glucose concentration 9 g/L and xylose concentration 45 g/L. Xylitol obtained from ratio 1:5 was 2.85 g/L while xylitol obtained from control medium, which is the medium that contained only xylose 45 g/L was 0.57 g/L, thus the addition of glucose to fermentation medium can increase the production of xylitol.