Development of periphytic diatoms on different artificial substrates in the Eastern Adriatic Sea

The settling of diatoms as fouling organisms on a certain substrate is greatly influenced by substrate characteristics and the preferences of a diatom community and diatom species. A distinction among substrates can be made by analysing the specific abundance and composition of diatoms on different substrates. In this study, 11 different artificial substrates were exposed to a marine environment for a period of 30 days. Abundance and taxonomic composition of periphytic diatoms was determined on each of the substrates and on shoots of the marine seagrass Posidonia oceanica. The aim was to compare diatom community structure on different newly colonized surfaces. On all surfaces examined, periphytic diatoms were the pioneering organisms with differences in quantitative and qualitative composition on the different substrates. Taxonomic analysis of diatom communities on the substrates examined revealed 41 diatom taxa, with the dominant genera Cylindrotheca, Amphora, Nitzschia, Cocconeis and Navicula. Given that all the examined artificial substrates were solid materials, differences in the abundance and species composition of diatoms found between the materials point to the substrates’ physical and chemical characteristics as a major influence on the final settling of diatoms. Knowledge from investigating the settlement of fouling organisms on anthropogenic substrates can have future use in management of waste materials that end up in the marine environment

Development of periphytic diatoms on different artificial substrates in the sea

Morski okoliš je specifično stanište u kojemu su svi supstrati vrlo brzo podložni procesu naseljavanja od strane živih organizama. U ovom istraživanju, koje je provedeno na lokaciji Puntamika kod Zadra, analiziran je perifiton na 11 različitih podloga nakon mjesec dana izlaganja u morskom okolišu (7. ožujak - 6. travanj 2012). Analizirana je abundancija perifitonskih dijatomeja na svakoj podlozi, te na dva izdanka morske cvjetnice Posidonia oceanica L. nađenih blizu lokacije gdje su podloge postavljene. Rezultati su pokazali da postoji, ponegdje i vrlo značajna, razlika u abundanciji dijatomeja ovisno o različitim fizičkim i kemijskim karakteristikama materijala podloge. Taksonomskom analizom zajednice dijatomeja utvrđen je 41 rod, od kojih su rodovi Amphora, Cylindrotheca, Nitzschia, Cocconeis i Navicula bili dominatni.Marine environment is a specific habitat where all substrates are very quickly subjected to colonisation process of living organisms. In this study, that took place at the location Puntamika near Zadar, 11 different artificial substrates were exposed to marine environment for a month (March 7th - April 6th 2012) and consequently periphytic diatoms analysed. The abundance of periphytic diatoms was determined on each of the substrate and on the two shoots of marine seagrass Posidonia oceanica L. Results showed significant differences in the abundance of diatoms between substrates. Such distinction is the consequence of different physical and chemical characteristics of the substrates. Taxonomic analysis of diatom communities revealed 41 diatom genera, and Amphora, Cylindrotheca, Nitzschia, Cocconeis and Navicula were recognized as dominant in peryphitic communities

Development of periphytic diatoms on different artificial substrates in the sea

Morski okoliš je specifično stanište u kojemu su svi supstrati vrlo brzo podložni procesu naseljavanja od strane živih organizama. U ovom istraživanju, koje je provedeno na lokaciji Puntamika kod Zadra, analiziran je perifiton na 11 različitih podloga nakon mjesec dana izlaganja u morskom okolišu (7. ožujak - 6. travanj 2012). Analizirana je abundancija perifitonskih dijatomeja na svakoj podlozi, te na dva izdanka morske cvjetnice Posidonia oceanica L. nađenih blizu lokacije gdje su podloge postavljene. Rezultati su pokazali da postoji, ponegdje i vrlo značajna, razlika u abundanciji dijatomeja ovisno o različitim fizičkim i kemijskim karakteristikama materijala podloge. Taksonomskom analizom zajednice dijatomeja utvrđen je 41 rod, od kojih su rodovi Amphora, Cylindrotheca, Nitzschia, Cocconeis i Navicula bili dominatni.Marine environment is a specific habitat where all substrates are very quickly subjected to colonisation process of living organisms. In this study, that took place at the location Puntamika near Zadar, 11 different artificial substrates were exposed to marine environment for a month (March 7th - April 6th 2012) and consequently periphytic diatoms analysed. The abundance of periphytic diatoms was determined on each of the substrate and on the two shoots of marine seagrass Posidonia oceanica L. Results showed significant differences in the abundance of diatoms between substrates. Such distinction is the consequence of different physical and chemical characteristics of the substrates. Taxonomic analysis of diatom communities revealed 41 diatom genera, and Amphora, Cylindrotheca, Nitzschia, Cocconeis and Navicula were recognized as dominant in peryphitic communities

Comparative study of antimicrobial potential and DNA/BSA binding affinity of silver(I) and gold(III) coordination compounds with 1,6-naphthyridine

In the present study, synthesis of silver(I) and gold(III) coordination compounds with 1,6-naphthyridine (1,6-naph), {[Ag(1,6-naph)(H2O)](BF4)}n (1) and [AuCl3(1,6-naph)] (2), was reported. The methods used for the structural characterization of a new compound 1 included IR, NMR (1H and 13C) and UV-Vis spectroscopy, cyclic voltammetry and single-crystal X-ray diffraction analysis. The crystallographic results showed that compound 1 represents silver(I) coordination polymer, in which 1,6-naph ligand acts as a bidentate bridging ligand connecting two Ag(I) ions via its N1 and N6 nitrogen atoms, while the third coordination site of the metal ion is occupied by the water oxygen atom, resulted in a T-shape geometry. Compounds 1 and 2 were evaluated in vitro for antimicrobial activity against five bacterial and two Candida species, while their cytotoxicity was tested on the normal human lung fibroblast cell line (MRC-5). Compound 1 has manifested a remarkable antifungal activity on both tested Candida strains (C. albicans and C. parapsilosis) with minimal inhibitory concentrations (MICs) of 1.43 and 11.38 µM (0.49 and 3.9 µg/mL), respectively, while no significant antimicrobial activity was observed for 2. Moreover, silver(I) coordination polymer 1 inhibits the hyphae formation of C. albicans at subinhibitory concentration. The binding affinity of both compounds 1 and 2 with calf thymus DNA (ct-DNA) and bovine serum albumin (BSA) was studied by fluorescence spectroscopy, indicating their ability to interact with these biomolecules, with compound 2 being more reactive