ABSTRACT
The efficiency of interaction (efficiency of energy transfer) between various quantum dots (QDs) and photosynthetic reaction centers (RCs) from the purple bacterium Rhodobacter sphaeroides and conditions of long-term stability of functioning of such hybrid complexes in film preparations were investigated. It was found that dry films containing RCs and QDs and maintained at atmospheric humidity are capable to keep their functional activity for at least some months as judging by results of measurement of their spectral characteristics, efficiency of energy transfer from QDs to RCs, and RC electron-transport activity. Addition of trehalose to the films giving them still greater stability is especially expressed for films maintained at low humidity. These stable hybrid film structures are promising for further biotechnological studies for developing new phototransformation devices.
Subject(s)
Biotechnology , Photosynthetic Reaction Center Complex Proteins/metabolism , Quantum Dots/metabolism , Rhodobacter sphaeroides/metabolism , Electron Transport , Energy Transfer , Protein Stability , TrehaloseABSTRACT
AIM: VNTR-typing of Vibrio cholerae strains isolated in the territory of Russian Federation in 2012. MATERIALS AND METHODS: 71 Vibrio cholerae O3 and 3 V cholerae O1/O139 strains were used in the study. Genotyping was performed by using PCR for 5 VNTR-loci. RESULTS: Multilocus VNTR-typing allowed to group the strains into 31 VNTR-genotypes. Genotypes were divided among 10 discrete clusters by results of a cluster analysis. The presence of tcpA gene is clearly linked with the presence of VcB locus. Each geographic region was characterized by their own VNTR-genotypes. CONCLUSION: In the course of the carried out VNTR-genotyping of V. cholerae isolated in 2012, 2 types of vibrio population formation were detected. A geographic attachment to specific regions was characteristic for most of the genotypes.
Subject(s)
Fimbriae Proteins/genetics , Minisatellite Repeats , Phylogeny , Vibrio cholerae/genetics , Cholera/epidemiology , Cholera/microbiology , Culture Media , Fimbriae Proteins/classification , Gene Expression , Genetic Loci , Genotype , Humans , Multilocus Sequence Typing/methods , Phylogeography , Polymerase Chain Reaction , Russia/epidemiology , Vibrio cholerae/classification , Vibrio cholerae/isolation & purificationABSTRACT
Computer analysis revealed seven potential variable-number tandem-repeat (VNTR) loci in the Vibrio cholerae genome. Specific primers were designed to amplify locus VcA located on chromosome 2 and containing a TGCTGT repeat. The locus was found in all tested strains from a V. cholerae strain collection, the repeat number varying 3 to 23. In total, 14 VcA alleles were observed. The VcA locus was proposed as a marker for the molecular typing of V. cholerae strains.
Subject(s)
Minisatellite Repeats , Vibrio cholerae/genetics , Algorithms , Alleles , Bacterial Typing Techniques/methods , Base Sequence , DNA Primers , Databases, Nucleic Acid , Molecular Sequence Data , Polymerase Chain Reaction/methods , Vibrio cholerae/classificationABSTRACT
Y. pestis cells have been shown capable of binding fibronectin (FN), the presence of adhesion pili considerably enhancing FN binding. The study has established that, along with FN, native adhesive pili, but not subunits, are capable of binding mucin and ganglioside. Structures similar to FN-binding curlings of Escherichia have been found on the surface of Y. pestis cells. The expression of curling-like structures does not depend on the presence of plasmids in Y. pestis cells.
