BOD biosensor based on the yeast Debaryomyces hansenii immobilized in poly(vinyl alcohol) modified by N-vinylpyrrolidone

Abstract

An amperometric biosensor for assessing the biochemical oxygen demand (BOD) was formed by immobilizing Debaryomyces hansenii VKM Y-2482 yeast cells in poly(vinyl alcohol) modified by N-vinylpyrrolidone. Modification provided for a high sensitivity and stability of the bioreceptor. A high oxidative activity of the receptor element and the absence of any toxic effect of assayed compounds were shown for 34 substrates (alcohols, carbohydrates, carboxylic acids, amino acids, nitrophenols and surfactants) that may occur in wastewaters. Estimates of the measurement range and region of the linear dependence of signals on the BOD level, pH and temperature sensitivities, dependences of signals on concentrations of salts, stability, Michaelis kinetic constants and assay rates were obtained. The BOD values determined by the biosensor in assayed wastewater samples were shown to have a high correlation with those obtained by the standard dilution method.

A yeast co-culture-based biosensor for determination of waste water contamination levels

“…The greatest correlation with the standard method is observed for the sensor based on the co-culture of P. angusta, A. adeninivorans and D. hansenii immobilized in PVA modified by N-vinylpyrrolidone. It is important to note that the correlation coefficient for the data obtained by the standard method and using a biosensor based on the developed co-cultures was higher than in most counterparts described [4,6], including the biosensor based on the single D. hansenii strain [10]. For all biosensors the BOD values coincide with those obtained by the standard method with account for confidential intervals.…”

“…Thus, a single BOD assay using the developed analyzer requires less time (3-4 min) as compared with a BOD assay done by means of other models of biosensor analyzers (10-15 min) [13,22,23]. The lower boundary of the determined BOD 5 values by the developed biosensors is somewhat inferior to the biosensor based on the single strain D. hansenii VKM Y-2482, immobilized in gel of chemically modified PVA, described in [10]. However, for most real-life samples this value of the lower boundary is acceptable.…”

“…It is important to note that, unlike the biosensor based on the single strain D. hansenii immobilized in gel of chemically modified PVA [10], the use of the biosensor based on the coculture of three microorganisms makes it possible to significantly broaden the range of substrates oxidized by the bioreceptor. This will lead to increase the correctness of assaying real-life samples of waste waters and will ensure a wide application of the developed biosensor in practice.…”

“…Gel of poly(vinyl alcohol) modified by N-vinylpyrrolidone was used in the development of biosensors' recognition elements to immobilize the co-cultures. The use of N-vinylpyrrolidone for modification of PVA makes it possible to significantly increase the longtime stability of produced receptor elements at a high sensitivity and broad substrate specificity preserved [10].…”

“…To prepare PVA modified by N-vinylpyrrolidone, an aqueous solution of cerium ammonium nitrate (NH 4 ) 2 Ce(NO 3 ) 6 and N-vinylpyrrolidone were added to an aqueous solution of PVA (molecular mass, 1.0·10 5 -1.1·10 5 amu) at constant mixing at 40°С for 3 h [10].…”