Biocompatible Silica-Polyethylene Glycol-Based Composites for Immobilization of Microbial Cells by Sol-Gel Synthesis.

Biocatalysts based on the methylotrophic yeast VKM Y-2559 immobilized in polymer-based nanocomposites for the treatment of methanol-containing wastewater were developed. The organosilica composites with different matrix-to-filler ratios derived from TEOS/MTES in the presence of PEG (SP-composite) and from silicon-polyethylene glycol (STP-composite) differ in the structure of the silicate phase and its distribution in the composite matrix. Methods of fluorescent and scanning microscopy first confirmed the formation of an organosilica shell around living yeast cells during sol-gel bio-STP-composite synthesis.

Impact of hydrophilic polymers in organosilica matrices on structure, stability, and biocatalytic activity of immobilized methylotrophic yeast used as biofilter bed.

The impact of hydrophilic polymers in an organosilica matrix on the features and performance of immobilized methylotrophic yeast cells used as biocatalysts was investigated and described. Yeast cells were immobilized in a matrix made of tetraethoxysilane (TEOS) and methyltriethoxysilane (MTES) by one-step sol-gel route of synthesis in the presence of polyethylene glycol (PEG) or polyvinyl alcohol (PVA). Organosilica shells were spontaneously built around cells as a result of yeast immobilization at a TEOS to MTES ratio of 85/15 vol% and hydrophilic polymer (PEG or PVA).

Silica sol-gel encapsulated methylotrophic yeast as filling of biofilters for the removal of methanol from industrial wastewater.

This research suggests the use of new hybrid biomaterials based on methylotrophic yeast cells covered by an alkyl-modified silica shell as biocatalysts. The hybrid biomaterials are produced by sol-gel chemistry from silane precursors. The shell protects microbial cells from harmful effects of acidic environment.