Isolation and characterization of mutated alcohol oxidases from the yeast Hansenula polymorpha with decreased affinity toward substrates and their use as selective elements of an amperometric biosensor.

Background: Accurate, rapid, and economic on-line analysis of ethanol is very desirable. However, available biosensors achieve saturation at very low ethanol concentrations and thus demand the time and labour consuming procedure of sample dilution.

Results: Hansenula polymorpha (Pichia angusta) mutant strains resistant to allyl alcohol in methanol medium were selected.

Metabolically engineered methylotrophic yeast cells and enzymes as sensor biorecognition elements.

An extended definition of the term metabolic engineering is given and its successful use in the construction of biorecognition elements of sensors is demonstrated. It is shown that genetic and chemical modifications of methylotrophic yeast cells provide directed changes in their physiological responses towards methanol, ethanol and formaldehyde resulting in enhanced selectivity and shorter time response of the corresponding potentiometric and amperometric biosensors.