Quantitative detection of the oil-degrading bacterium Acinetobacter sp. strain MUB1 by hybridization probe based real-time PCR

Quantitative detection of the oil-degrading bacterium Acinetobacter sp. strain MUB1 was performed using the SoilMaster^™ DNA Extraction Kit (Epicentre, Madison, Wisconsin) and hybridization probe based real-time PCR. The detection target was the alkane hydroxylase gene (alkM). Standard curve construction showed a linear relation between log values of cell concentrations and real-time PCR threshold cycles over five orders of magnitude between 5.4±3.0×10⁶ and 5.4±3.0×10² CFU ml⁻¹ cell suspension. The detection limit was about 540 CFU ml⁻¹, which was ten times more sensitive than conventional PCR. The quantification of Acinetobacter sp. strain MUB1 cells in soil samples resulted in 46.67%, 82.41%, and 87.59% DNA recovery with a detection limit of 5.4±3.0×10⁴ CFU g⁻¹ dry soil. In this study, a method was developed for the specific, sensitive, and rapid quantification of the Acinetobacter sp. strain MUB1 in soil samples.     

DFT and TDDFT study on the electronic structure and photoelectrochemical properties of dyes derived from cochineal and lac insects as photosensitizer for dye-sensitized solar cells

Essential parameters related to the photoelectrochemical properties, such as ground state geometries, electronic structures, oxidation potential and electron driving force, of cochineal insect dyes were investigated by DFT and TDDFT at the B3LYP/6-31+G(d,p) level of the theory. The results show that the major charge flow dynamic for all dyes is the HOMO→LUMO transition. The bi-coordinated binding mode, in which the dye uses one carboxyl- and hydroxyl oxygen bound to Ti(IV), is found for all dye-TiO₂ systems. Additionally, the doubly bi-coordinated binding mode in which the dye used both carboxyl groups bound to two Ti(IV) is also possible due to high energy distribution occupied at anchoring groups. This study highlights that most of these insect dyes can be good photosensitizers in dye-sensitized solar cells based on their strong binding to the TiO₂ surface, good computed excited state oxidation potential and thermodynamically favored electron driving force.