Use of the yeast-like cells of Tremella fuciformis as a cell factory to produce a Pleurotus ostreatus hydrophobin.

Objectives: To obtain hydrophobin, a Class I hydrophobin gene, Po.hyd from Pleurotus ostreatus, was transformed into the yeast-like cells of Tremella fuciformis using Agrobacterium tumefaciens.

Results: The hydrophobin Po.HYD from P. ostreatus was heterogeneously expressed by the yeast-like cells of T. fuciformis. Plasmids harboring the Po.hyd gene driven by endogenous glyceraldehyde-3-phosphate dehydrogenase promoter were transformed by A. tumefaciens. The integration and expression of the rPo.HYD in the T. fuciformis cells were confirmed by PCR, Southern blot, fluorescence microscopy and quantitative real-time PCR. SDS-PAGE demonstrated that the rPo.HYD was extracted with the expected MW of 14 kDa. The yield of purified rPo.HYD was 0.58 mg/g dry wt. The protein, with its ability to stabilize oil droplets, exhibited a better emulsifying activity than the typical food emulsifiers Tween 20 and sodium caseinate.

Conclusion: Tremella fuciformis can be used as a cell factory to produce hydrophobin on a large scale for the food industry.