Yeast Debaryomyces hansenii within ORMOSIL Shells as a Heterogeneous Biocatalyst

Abstract

The relevant sol-gel encapsulation methods to design ORMOSIL (organically modified silica) protective shells around Debaryomyces hansenii yeast cells have been studied. Encapsulation is based on spontaneous “cell-in-shell” 3D structures. The physiological activity of the sol-gel encapsulated cells was determined by measurement of the oxidative activity of a BOD biosensor containing ORMOSIL-encapsulated cells. It was shown that the shells around the microbial cells did not prevent substrate diffusion and had excellent protection from extreme environmental factors (heavy metal ions, high pH, and UV radiation). In addition, it was found that the BOD biosensor surpasses some other known biosensors in their basic characteristics, including sensitivity, stability, and reproducibility. These results are important for the development of innovative methods of cell encapsulation and the creation of biocatalysts used in biotechnology and ecology.