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Enzyme and Microbial Technology Jan 2020A mediator biosensor based on Paracoccus yeei bacteria for assaying the toxicity of perfumery and cosmetics samples was developed. An approach to selecting an...
A mediator biosensor based on Paracoccus yeei bacteria for assaying the toxicity of perfumery and cosmetics samples was developed. An approach to selecting an electron-transport mediator based on the heterogeneous electron transfer constants for investigated mediators (k) and the mediator-biomaterial interaction constants (k) was proposed. Screening of nine compounds as potential mediators showed a ferrocene mediator immobilized in graphite paste to have the highest efficiency of electron transfer to the graphite-paste electrode (the heterogeneous transfer constant, 0.4 ± 0.1 cm/s) and a high constant of interaction with P. yeei (0.023 ± 0.001 dm/(g·s)). A biosensor for toxicity assessment based on the ferrocene mediator and P. yeei bacteria was formed. The biosensor was tested on samples of four heavy metals (Cu, Zn, Pb, Cd) and two phenols (phenol and p-nitrophenol). Proceeding from the EC index, it was found that the use of the ferrocene mediator made the biosensor more sensitive to investigated toxicants than most analogues described. Toxicity determination of four perfumery and cosmetics samples by the developed biosensor showed prospects of using this system for real-time toxicity monitoring of samples.
Topics: Biosensing Techniques; Metals, Heavy; Nitrophenols; Paracoccus; Perfume; Phenols; Toxicity Tests
PubMed: 31731957
DOI: 10.1016/j.enzmictec.2019.109435 -
Clinical Laboratory Aug 2019Parotid cyst is a common problem in patients treated by surgeons. However, Paracoccus yeei was isolated from an aerobic blood culture in a patient with parotid cyst as...
BACKGROUND
Parotid cyst is a common problem in patients treated by surgeons. However, Paracoccus yeei was isolated from an aerobic blood culture in a patient with parotid cyst as an unusual etiologic opportunistic agent.
METHODS
Since old biochemical identification kits are not able to identify this species, MALDI-TOF MS correctly was recommended to identify this isolate. Its identity was confirmed by sequencing of the 16S rRNA gene.
RESULTS
The aligned sequences (16S rRNA gene) were used for a phylogenetic analysis (phylogenetic tree), which was produced using the BLAST pair-wise alignments. The sequence analysis determined that the best matches were with Paracoccus yeei.
CONCLUSIONS
Paracoccus yeei has been reported as a rare opportunistic human pathogen, we should actively com-municate to the clinic to improve the real positive rate.
Topics: Bacterial Typing Techniques; Cysts; DNA, Bacterial; Humans; Male; Middle Aged; Paracoccus; Parotid Diseases; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
PubMed: 31414739
DOI: 10.7754/Clin.Lab.2019.190125