Biomedical subjects

M M Maĭdan

Publications and source records attributed to M M Maĭdan.

3 recordsLinked to original sources

PubMedDate not supplied

[Metabolic engineering in design of cellular elements of biosensors].

An extended definition of the term "metabolic engineering" is given and main spheres of its using in fundamental studies and modern biotechnology are discussed in this article. Emphasis is made on specific using the approaches of metabolic engineering in construction of the cell elements of sensors based on the use of mutant and chemically modified cells of methylotrophic yeasts. This investigation is designed in the laboratory of Biochemical Genetics of the Division of Cell Regulatory Systems, A. V. Palladin Institute of Biochemistry. Genetic and chemical modifications have allowed to provide some directed changes in cell sensoring output toward methanol, ethanol and formaldehyde that result in enhanced selectivity and shortened time-output of the corresponding potentiometric and amperometric sensors.

Biomedical Engineering↗

PubMedDate not supplied

[A new oxidase method for analyzing L-lactate].

A new oxidase-coupled colorimetric method for analysis of L-lactate in biological fluids has been developed without use of peroxidase. The method is based on lactate oxidase-catalysed transformation of lactate to pyruvate which is determined photometrically in the next dye-producing reaction of 3-methyl-2-benzothiazolinone hydrazone (MBTH) in the presence of ferric ions. Sensitivity of the method is estimated as 0.1 micromole of analyte in 4-ml of reaction mixture. Linearity is observed in the range 0.1-1.0 micromole of L-lactate in sample (r = 0.99943; p < 0.0001). The developed method has been adapted for assay of L-lactic acid in kefirs and yogurts.

Catalysis↗

PubMedDate not supplied

[Modern methods for formaldehyde, methanol and ethanol analysis].

It is necessary to create very specific and sensitive methods for assaying formaldehyde and methanol which are produced on the large scale and are very toxic and have mutagenic and carcinogenic action on living organisms. The methods for determination of formaldehyde, methanol and ethanol in the environment and fermentation products published and developed by the authors are reviewed in this paper. Most of the known methods are not sufficiently selective and sensitive and some of them are very expensive. Classical chemical, enzymatic, chemosensor and biosensor approaches used for methanol and formaldehyde assay are described. Enzymatic methods exploiting alcohol oxidase isolated from the mutant over-producing strain of methylotrophic yeast Hansenula polymorpha permit efficient determination of formaldehyde in industrial wastewaters. Enzymatic-chemical method based on the use of alcohol oxidase and 4-amino-5-hydrazine-3-mercapto-1,2,4-triazole (AHMT) allows simultaneous determination of methanol and formaldehyde. The technology of biosensor construction and their bioanalytical characteristics are described. Experimental data concerning amperometric and potentiometric biosensors based on the use of genetically modified cells of methylotrophic yeast Hansenula polymorpha are reviewed. The possibility to use alcohol oxidase-based biosensor for the assay of methanol in wastewater is demonstrated.

Biosensing Techniques↗