Registration of BOD using Paracoccus yeei bacteria isolated from activated sludge.

This work investigated the properties of Paracoccus yeei VKM B-3302 bacteria isolated from activated sludge and immobilized in an N-vinylpyrrolidone-modified poly(vinyl alcohol) matrix. The developed hydrogel formed a network structure to enable the entrapment of microbial cells with their viability and biocatalytic properties preserved, which ensured the technological possibility of replicating expendable biosensor receptor elements. A new ratio of the components for the synthesis selected in this work enabled producing a copolymer of an earlier undescribed chemical structure, which can be efficiently used for immobilization of highly sensitive P. yeei bacteria. A biological oxygen demand (BOD) biosensor with these bacteria and matrix was shown to possess a long-time stability exceeding that described earlier, to have a broad substrate specificity and to exceed approximately tenfold the nearest analogues by its sensitivity and the lower boundary value of 0.05 mg/dm(3). The biosensor enabled assays of water samples initially attributed to pure samples (the BOD range, 0.05-5.0 mg/dm(3)). BOD assays of water samples from various sources showed the use of the receptor element of this composition to enable the data that closely correlated with the standard method (R (2) = 0.9990).