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.

Glucose biosensor based on screen-printed electrode modified with silicone sol–gel conducting matrix containing carbon nanotubes

“…Heterogenic electron transfer constant equaling 0.0098 ± 0.0005 cm/s confirms quite a high efficiency of the studied matrix as compared to the matrices based on organic materials and CNT described in Nguyen and Zink (2002)and Ngo et al (2019). Although the received constants are slightly lower than the constants of matrices based on multi-walled CNT and high-oriented polyaniline nanotubes (Ponamoreva et al 2018), generally it may be still suggested that the developed electrodes have high analytical properties.…”

“…5) to determine the main characteristics of the electrochemical process. Anodic peak was reached at potential E pa = − 400 mV, cathodic peak at E pc = − 490 mV; difference of peaks (ΔE p ) amounted to 90 mV, which corresponds with the electrochemical behavior of glucose oxidase (Ponamoreva et al 2018). This is suggestive of glucose oxidase coenzyme's (FAD) capability to reduce to FADH 2 and oxidize in such conditions.…”

Novel Organochlorinated Xerogels: From Microporous Materials to Ordered Domains

“…Organically modified silicates (ORMOSILs) are hybrid silicon xerogels that combine the mechanical, thermal, and structural rigidity and stability of inorganic materials with the flexibility and functionality of organic molecules [ 1 ]. These properties favor their utilization as chemical and optical sensors [ 2 , 3 , 4 , 5 , 6 , 7 ], catalysts [ 8 , 9 ], coatings [ 10 , 11 , 12 , 13 , 14 ], chromatographic agents [ 15 , 16 ], nanoprobes, and photovoltaic cells [ 17 , 18 ], among others.…”

Hybrid Xerogels: Study of the Sol-Gel Process and Local Structure by Vibrational Spectroscopy

“…The data in Table S3 (Supplementary Material) for the three chloroalkyl series show that the contribution of the LO 4 band (attributable to the total percentage of (SiO) 4 rings) increases with higher percentage of precursor. This is a relevant finding, given that this band is also associated with the presence of ordered structures in the literature [ 5 , 51 , 65 ]. Its presence is closely related to a decrease in the degree of crosslinking in the xerogel, in agreement with the shifts at lower wavelengths of the TO 4 band, which is associated with the silicon network [ 13 ].…”

“…Organically modified silicon xerogels (ORMOSILs) are attracting considerable interest for their application in new-generation technologies, being utilized in chemical and optical sensors [ 1 , 2 , 3 , 4 , 5 , 6 ], for catalysis [ 4 , 5 ], in coatings [ 6 , 7 , 8 , 9 , 10 ], for chromatography [ 11 , 12 ], and in pharmacy [ 13 ]. They have great chemical versatility and can be efficiently modified for specific applications due to their combination of highly varied mechanical, optical and textural properties [ 14 ].…”