Effect of β-glucan on stress tolerances and biocontrol efficacy of Cryptococcus laurentii against Penicillium expansum in pear fruit

The objective of this study was to determine the effect of β-glucan on stress tolerances and biocontrol efficacy of Cryptococcus laurentii against Penicillium expansum in pear fruit. The results showed that biocontrol efficacy and the population growth of C. laurentii harvested from nutrient yeast dextrose broth amended with β-glucan at 0.5 % (NYGB) were significantly higher compared to that harvested from nutrient yeast dextrose broth. Moreover, the viability of C. laurentii under heat, oxidative and water stress was markedly improved by cultivating in NYGB. In addition, the activity of superoxide dismutase in yeast cells was induced after exposure to heat, oxidative and water stresses. These results indicate that the application of β-glucan might be an effective method to improve the stress tolerances and biocontrol efficacy of C. laurentii. To our knowledge, this is the first report regarding the function of β-glucan in enhancing various stress tolerances of post-harvest biocontrol yeasts.