Breeding and fermentation characterization of Pachysolen Tannophilus mutant with high ethanol productivity from xylose

Currently, few strains can utilize xylose to produce ethanol with very low productivity. By the method of mutation breeding to these strains the rate of lignocellulosic utilization could be improved. In this study, the initial Pachysolen tannophilus As 2.1585 was treated by N+ ions implantation of 15 keV. The survival curve showed a saddle model. Considering the survival rate and range of positive mutation, the N+ ions implantation of 12.5 × 1014 ions/cm for mutation breeding of Pachysolen tannophilus was selected. A Pachysolen tannophilus mutant mut-54, which had perfect genetic stability of producing ethanol was screened out after continuous 7 passages. The mut-54 had a higher xylose consumption rate, biomass accumulation and ability of ethanol-resistant than the parent strain. Compared with the parent strain, the ethanol concentration fermented by the mut-54 for 72 h increased by 12.74%, which was more suitable for producing ethanol from xylose than the parent strain. (authors)