Differentiation of Closely Related Oak-Associated Gram-Negative Bacteria by Label-Free Surface Enhanced Raman Spectroscopy (SERS)

Due to the harmful effects of chemical fertilizers and pesticides, the need for an eco-friendly solution to improve soil fertility has become a necessity, thus microbial biofertilizer research is on the rise. Plant endophytic bacteria inhabiting internal tissues represent a novel niche for research into new biofertilizer strains. However, the number of species and strains that need to be differentiated and identified to facilitate faster screening in future plant-bacteria interaction studies, is enormous. Surface enhanced Raman spectroscopy (SERS) may provide a platform for bacterial discrimination and identification, which, compared with the traditional methods, is relatively rapid, uncomplicated and ensures high specificity. In this study, we attempted to differentiate 18 bacterial isolates from two oaks via morphological, physiological, biochemical tests and SERS spectra analysis. Previous 16S rRNA gene fragment sequencing showed that three isolates belong to Paenibacillus, 3—to Pantoea and 12—to Pseudomonas genera. Additional tests were not able to further sort these bacteria into strain-specific groups. However, the obtained label-free SERS bacterial spectra along with the high-accuracy principal component (PCA) and discriminant function analyses (DFA) demonstrated the possibility to differentiate these bacteria into variant strains. Furthermore, we collected information about the biochemical characteristics of selected isolates. The results of this study suggest a promising application of SERS in combination with PCA/DFA as a rapid, non-expensive and sensitive method for the detection and identification of plant-associated bacteria

Zinc oxide nanoparticle and bovine serum albumin interaction and nanoparticles influence on cytotoxicity in vitro

Bovine serum albumin (BSA) and zinc oxide nanoparticles (ZnO NPs) are chosen as a model system to investigate NPs-protein corona complex formation. ZnO NPs with average size of ∼20 nm are coated with BSA using covalent and non-covalent conjugation at temperatures of 4 ◦C and 20 ◦C. The interaction mechanism between ZnO NPs and BSA is studied by using UV–vis absorption, fluorescence, synchronous fluorescence and Raman spectroscopy. Raman spectra of BSA in the presence of ZnO NPs are registered for the first time and confirm decreased -helix content, increased unstructured folding and -sheet content in BSA structure. The synchronous fluorescence spectra revealed that the hydrophobicity of the tyrosine residue is decreased and that of the tryptophan is increased. The relation of elucidated changes in BSA structure of BSA-coated ZnO NPs cytotoxicity is tested for CHO cell viability and reactive oxygen species (ROS) generation in vitro. Covalent and non-covalent binding of BSA to ZnO NPs reduces ZnO NPs cytotoxicity and ROS generation, however changes in BSA conformation makes corona less protective against ZnO NPsBiochemijos katedraKauno technologijos universitetasVytauto Didžiojo universiteta

Entrepreneurship and its impact for economic growth

In this paper there is taking a closer look at how the figure of the entrepreneur and entrepreneurship are treated in economic theory. Entrepreneurship is seen by many authors as a very important economic phenomenon. This due to, among other considerations, the possibility that economic growth can be enhanced, employment opportunities created through encouragement of entrepreneurship and self-employment. The research has taken a new direction, bringing out the separate and distinct function of the entrepreneur in contrast to that of the manager. A great deal of emphasis is placed on this difference, because entrepreneurship has a quality of its own. The essence of entrepreneurship is being different: while manager must operate under normal conditions and in routine business, a successful entrepreneurship requires exactly the opposite qualities. Astonishingly in Lithuania, in the literature on economics the entrepreneur and entrepreneurship has been largely left out. The paper emphasize successful implementation of entrepreneurship development strategy into the Lithuanian economy is the key to business growth that would build extra job places and would be a considerable support of enhancing the country's economic activit

Impact of graphene oxide on viability of Chinese hamster ovary and mouse hepatoma MH-22A cells

Impact Factor: 3.207The evaluation of the cyto- and bio-compatibility is a critical step in the development of graphene oxide (GO) as a new promising material for in vivo biomedical applications. In this study, we report the impact of GO, with and without the addition of bovine serum albumin, on healthy (Chinese hamster ovary) and a cancer (mouse hepatoma MH-22A) cells viability and the estimation of the intracellular distribution of GO inside the cells in vitro. The viability tests were performed using a colony formation assay. The intracellular distribution of GO was estimated using Raman spectroscopy and imaging. The viability of both cell lines decreased with increasing concentration of graphene oxide (12.5–50.0 μg/ml): in the case of Chinese hamster ovary cells viability decreased from 44% to 11%, in the case of mouse hepatoma MH-22A cells – from 22% to 3%. These cell lines significantly differed in their response to GO and GO–BSA formulations. The results of viability tests correlate with results of atomic force microscopy and Raman spectroscopy and imaging findings. The GO influence on cell morphology changes, cell structure, cells colony growth dynamics and GO accumulation inside the cells was higher in the case of mouse hepatoma MH-22A cellsBiologijos katedraKauno technologijos universitetasVytauto Didžiojo universiteta

Increase of the roughness of the electrode surface due to the exposure to high-voltage electric pulses as revealed by atomic force microscopy

The changes of the surface topography of stainless-steel and aluminium electrodes occurring due to the action of electric pulses which are commonly utilized in cell electroporation procedures, have been studied by using atomic force microscopy. The surfaces of the polished stainless-steel electrodes were smooth - the average roughness was 13-17 mm and the total roughness 140-180 mm. The total roughness of the aluminium electrodes was about 320 mm.[...]Biologijos katedraKauno technologijos universitetasVytauto Didžiojo universiteta