Immobilization of Hyperthermophilic Archaeon Thermococcus onnurineus NA1 on Amine-coated Silica Material for H2 Production

Abstract

Hyperthermophilic archaeon, Thermococcus onnurineus NA1 has high potential for H2 production on carbon monoxide, sodium formate and starch. For H2 production using immobilization of T. onnurineus NA1, celite and porous silica beads as supporting materials were investigated to adsorb cells of this strain. Experimental results of adsorption test and scanning electron microscopy showed that silica particles with properties such as regular spherical shape, amine-coated surface and porosity are favorable for adsorbing cells of T. onnurineus NA1. The maximum adsorptive capacity of the support was estimated to be 71.7 mg-dry cell weight per g-support. In repeated batch on sodium formate, immobilized T. onnurineus NA1 on the support showed the stability and reproducibility for H2 production. The initial H2 production rate was linearly increased as the batch culture was repeated probably due to the increase of concentration of immobilized cells. From this study, it was demonstrated that T. onnurineus NA1 can be simply immobilized by adsorption using amine-coated porous silica beads and H2 production using immobilized T. onnurineus NA1was feasible.rting materials were investigated to adsorb cells of this strain. Experimental results of adsorption test and scanning electron microscopy showed that silica particles with properties such as regular spherical shape, amine-coated surface and porosity are favorable for adsorbing cells of T. onnurineus NA1. The maximum adsorptive capacity of the support was estimated to be 71.7 mg-dry cell weight per g-support. In repeated batch on sodium formate, immobilized T. onnurineus NA1 on the support showed the stability and reproducibility for H2 production. The initial H2 production rate was linearly increased as the batch culture was repeated probably due to the increase of concentration of immobilized cells. From this study, it was demonstrated that T. onnurineus NA1 can be simply immobilized by adsorption using amine-coated porous silica beads and H2 production using immobilized T. onnurineus NA1was feasible.