초록
<P><B>Abstract</B></P> <P>Microbial immobilization is a key approach to enhance fermentation performance, especially with the advantages of low costs and the good surface properties of the lignocellulosic wastes, which can serve as natural carriers. This study investigated the capability of hydrothermal modification to improve the physicochemical properties of corn stalk carriers for microbial immobilization. Hydrothermal modification can degrade lignocellulosic structure by dissolving part of the components at different conditions. A temperature of 200 °C for 20 min with a carrier side length of 1 cm were selected as the optimal modification conditions. With these conditions, the specific surface area and porosity of the modified corn stalk carriers were 2.44 m<SUP>2</SUP>/g and 0.011 cm<SUP>3</SUP>/g, respectively, which were twice the values of untreated carriers. Immobilization tests showed that bacteria and yeast grew stably inside the modified carriers and that the immobilized biomass was 49% greater than that of the untreated carriers. After fermentation with bacteria, ethanol production in the modified carrier system was increased by 57% and 99% compared to the untreated carrier system and free bacteria, respectively. These findings confirmed that hydrothermal modification is efficient to improve lignocellulosic carrier properties to achieve better immobilization and fermentation performance, thus benefiting to the utilization of lignocellulosic wastes and their bioconversion processes.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Lignocellulosic waste can serve as a microbial carrier in bioconversion processes. </LI> <LI> Lignocellulosic carriers were hydrothermally modified for microbial immobilization. </LI> <LI> Specific surface area and porosity of corn stalks were improved by the modification. </LI> <LI> Conditions of 200 °C for 20 min with a 1 cm size were optimal for modifying the carriers. </LI> <LI> Modified carriers showed better immobilization and ethanol fermentation performance. </LI> </UL> </P>