Development of a flexible system for the simultaneous conversion of biomass to industrial chemicals and the production of industrial biocatalysts

A flexible system was developed for the simultaneous conversion of biomass to industrial chemicals and the production of industrial biocatalysts. In particular, the expression of a bacterial enzyme, beta-glucuronidase (GUS), was investigated using a genetically modified starch-degrading Saccharomyces strain in suspension cultures in starch media. Different sources of starch, including corn and waste potato starch, were used for yeast biomass accumulation and GUS expression studies under controls of inducible and constitutive promoters. A thermostable bacterial cellulase (El beta-1,4-endoglucanase) gene of Acidothermus cellulolyticus was also cloned into an episomal plasmid expression vector and expressed in the starch-degrading Saccharomyces strain.