Results: The engineered diploid strain, which contained multiple copies of three cellulase genes integrated into its
genome, was precultured in molasses medium (381.4 mU/g wet cell), and displayed approximately six-fold higher
phosphoric acid swollen cellulose (PASC) degradation activity than the parent haploid strain (63.5 mU/g wet cell).
When used to ferment PASC, the diploid strain produced 7.6 g/l ethanol in 72 hours, with an ethanol yield that
achieved 75% of the theoretical value, and also produced 7.5 g/l ethanol from pretreated rice straw in 72 hours.