Analysis of the Effect of Agitation and Aeration on Xylitol Production by Fermentation in Bioreactor with Kluyveromyces marxianus Using Hydrolized Tamarind Seed as Substrate

Abstract

Xylitol is a compound with high industrial value due to its chemical and physical properties; at an industrial level, xylitol is produced by catalytic hydrogenation of xylose, a process both costly and low-yield. As a viable alternative, xylitol can be produced by fermentation with yeasts that use xylose as an energy source, such as Kluyveromyces marxianus. As a substrate source we proposed the use of tamarind seed, with high xylose content in its structure. Making use of xylose by yeast plus the resulting xylitol, depend on various factors among which that of greatest impact is the presence of oxygen in the fermentation medium. Therefore, in this study, the effects of aeration and agitation on xylitol production using hydrolyzed tamarind seed as a substrate medium were evaluated, employing a 22 factorial experimental design with a central point. In this way, aeration and interaction of the factors (both aeration and agitation) were the ones which had a significant effect on xylitol production. The highest yield reached was of 0.71 g of xylitol/g of xylose with agitation at 100 rpm and, aeration at 0.1 vvm in semi anaerobic conditions.