A rapid microwave-assisted phosphoric-acid treatment on carbon fiber surface for enhanced cell immobilization in xylitol fermentation.

Abstract

A rapid microwave-assisted phosphoric-acid treatment (MP) was applied to modify the surface of carbon fibers (CFs) for cell immobilization and fermentation. After the novel treatment, the surface of CFs subjected to MP (CF-MP) contained the CPO and COP bonds and the surface area and hydrophilicity were enhanced, which improved the cell adhesion and growth compared with the raw CF. Because of these structural advantages, the biocompatibilities of the CF-MP as a cell carrier were improved according to the immobilization behavior of microorganisms and batch fermentation. The optimized immobilization efficiency of Candida tropicalis on the CF-MP was improved to 0.587 g g-1, and the maximum xylitol yield and volumetric productivity were 67.15% and 1.16 g h-1 L-1, respectively, which were substantially higher than that in case of the untreated CF. This indicated that the biocompatibility of CF improved after the favorable MP surface treatment, resulting in the enhancement of immobilized efficiency and xylitol fermentation.