Glycerol production through TPI1 defective Kluyveromyces marxianus at high temperature with glucose, fructose, and xylose as feedstock

Glucose, xylose, and fructose from biomass are renewable sources for glycerol production. Here, a TPI1 gene encoding triose phosphate isomerase (TPI) was identified in Kluyveromyces marxianus NBRC1777. The TPI1 gene was deleted in the KU70 defective K. marxianus, resulting in YZB115. YZB115 could grow with glucose, fructose, and xylose as sole carbon sources, which is contrary to the Saccharomyces cerevisiae TPI1 deletion strain. Under aerobic conditions, YZB115 fermented 80 g/L glucose, fructose, and xylose, producing 40.32, 41.84, and 18.64 g/L glycerol with productivities of 0.84, 0.50, and 0.22 g/L/h at 42 degrees C without by-product, respectively. The yields were about 0.5 g/g when hexoses were used, which is 98 % of the theoretical maximum. The yield decreased to 0.22 g/g when xylose was used. In summary, our study showed the potential of K. marxianus to produce glycerol and glycerol derivatives from cellulose, lignocellulosic, and inulin biomass at high temperature.