Floristic Composition and Taxonomic Structure of Algae in the Hyperhaline Reservoirs of the Northwestern Azov Sea Coast (Ukraine)

The article represents the results of long-term algological studies of hyperhaline reservoirs of the northwestern coast of the Azov Sea. The features of the floristic composition and taxonomic structure of algae in aquatic (water column and bottom), aquatic-terrestrial (water’s edge, dried up water bodies, drying area) and terrestrial (elevated non-flooding areas) habitats of these objects are displayed. A specificity of the studied algoflora lies in the absence of representatives of certain characteristic phyla for the salt-water and non-saline land and water habitats of the territory of Ukraine. It was established that species composition of the studied reservoirs is depleted in comparison with other non-saline and marine ecosystems. Totally, 123 algae species were identified. They represented 7 divisions, 10 classes, 27 orders, 47 families, 68 genera. The largest number of species included three phyla: Cyanoprokaryota – 65 species (52.9% of the total number of identified species), Bacillariophyta – 26 (21.1%), Chlorophyta – 22 (17.9%). The first places among the six leading orders were taken by cyanoprocaryotes from Oscillatoriales, Nostocales, Chroococcales and diatoms from Naviculales. The most numerous species at the family level are trichomous cyanoprocaryotes from Nostocaceae, Pseudanabaenaceae, and Phormidiaceae. There were found 23 leading genera – their species richness exceeds the average indicator (1.81 species). According to the results of original studies, it was noted that all taxonomic levels of algoflora of the hyperhaline reservoirs shows features of not only saline habitats, but also of the freshwater, marine and terrestrial extreme ecosystems. Such diversity of the algal population indicates an unstable hydrological regime and complex relations of water exchange between the hyperhaline reservoirs and nearby terrestrial and aquatic habitats

Fatty Acid Composition of Benthic Macroscopic Algal Growths and Peloids in the Ephemeral Reservoirs

The fatty acid composition of benthic macroscopic growths of algae and peloids in the ephemeral reservoirs on the Berdyansk Spit (near the Krasne Lake) and Arabat Spit (near the Zyablovs’ke Lake) was studied and analyzed. It is shown that fatty acid spectrum of benthic macroscopic algal growths and peloids largely coincides

Investigations of heme distortion, low-frequency vibrational excitations, and electron transfer in cytochrome c

Cytochrome (cyt) c is an important electron transfer protein. The ruffling deformation of its heme cofactor has been suggested to relate to its electron transfer rate. However, there is no direct experimental evidence demonstrating this correlation. In this work, we studied Pseudomonas aeruginosa cytochrome c551 and its F7A mutant. These two proteins, although similar in their X-ray crystal structure, display a significant difference in their heme outof- plane deformations, mainly along the ruffling coordinate. Resonance Raman and vibrational coherence measurements also indicate significant differences in ruffling-sensitive modes, particularly the low-frequency γa mode found between ~50-60 cm-1. This supports previous assignments of γa as having a large ruffling content. Measurement of the photoreduction kinetics finds an order of magnitude decrease of the photoreduction cross-section in the F7A mutant, which has nearly twice the ruffling deformation as the WT. Additional measurements on cytochrome c demonstrate that heme ruffling is correlated exponentially with the electron transfer rates and suggest that ruffling could play an important role in redox control. A major relaxation of heme ruffling in cytochrome c, upon binding to the mitochondrial membrane, is discussed in this context

Species Structure of Algae of the Saline Coastal Reservoirs of the Pryazov National Natural Park, Ukraine

The paper is devoted to the research of the species composition and taxonomic structure of algae in the saline coastal reservoirs of the Pryazov National Natural Park (PNNP). It is established that the species composition of algae in the studied reservoirs under modern conditions includes 153 species. These species represented 7 phyla, 11 classes, 32 orders, 61 families, 92 genera. The highest species richness at the phyla level showed Cyanoprokaryota (43.8% of the total number of species), Bacillariophyta (32.0%) and Chlorophyta (20.9%). These phyla include 148 species and form the basis of the species composition in the studied water bodies. The leading orders of algae in the researched reservoirs were Oscillatoriales and Synechococcales (23 and 20 species, respectively). The most diversely represented families were: Oscillatoriaceae (13 species), Nostocaceae, Leptolyngbyaceae, Naviculaceae (8 each), Microcoleaceae, and Bacillariaceae (7 each). The top list of the genera by this parameter: Leptolyngbya (6 species), Lyngbya, Nostoc, Phormidium, Nitzschia (5 each), Calothrix, Kamptonema, Cocconeis, Navicula (4 each). The highest frequency of occurrence among the identified species had also diatoms, cyanoprokaryotes and green algae: Halamphora coffeiformis (5.26%), Lyngbya aestuarii (4.21%), Cladophora siwaschensis (3.51%), Hantzschia amphioxys (3.33%), Nodularia harveyana (2.98%). Our research demonstrates that the species composition of algae of the studied saline coastal reservoirs of PNNP is quite impoverished in comparison with the partial soil algae flora, as well as the species list of algae in the freshwater reservoirs of Ukraine and seas. Specific features of the taxonomic composition of the saline coastal reservoirs are manifested in the association of organisms of fresh, marine and terrestrial habitats

Cyanoprokaryota of the Salt Marshes at the Pryazov National Natural Park, Ukraine

Cyanoprokaryota of salt marshes were investigated at three scientific sites: in the upper Utlyuk Estuary, on the coast of Lake Sivashik, and at Fedotov Spit. Data on species composition, systematic structure, leading families, and genera are provided. In total, 71 species of cyanoprokaryotes representing 3 orders, 10 families, and 22 genera. The dominant complex included representatives of the genera Schizothrix Kützing ex Gomont, Phormidium Kützing ex Gomont, Lyngbya C.Agardh ex Gomont, Leptolyngbya (Gomont) Anagnostidis & Komárek, Trichormus (Ralfs ex Bornet & Flahault) Komárek & Anagnostidis, Nostoc Vaucher ex Bornet & Flahault, and Nodularia Mert. ex Born. & Flah. The identified species are analyzed for their biotopic nature and their valence to the level of environmental salinity. The distribution of the identified species within the Ukrainian territory is considered

Heme-protein vibrational couplings in cytochrome c provide a dynamic link that connects the heme-iron and the protein surface

The active site of cytochrome c (Cyt c) consists of a heme covalently linked to a pentapeptide segment (Cys-X-X-Cys-His), which provides a link between the heme and the protein surface, where the redox partners of Cyt c bind. To elucidate the vibrational properties of heme c, nuclear resonance vibrational spectroscopy (NRVS) measurements were performed on 57Fe-labeled ferric Hydrogenobacter thermophilus cytochrome c 552, including 13C8-heme-, 13C 515N-Met-, and 13C15N-polypeptide (pp)-labeled samples, revealing heme-based vibrational modes in the 200- to 450-cm-1 spectral region. Simulations of the NRVS spectra of H. thermophilus cytochrome c552 allowed for a complete assignment of the Fe vibrational spectrum of the protein-bound heme, as well as the quantitative determination of the amount of mixing between local heme vibrations and pp modes from the Cys-X-XCys-His motif. These results provide the basis to propose that heme-pp vibrational dynamic couplings play a role in electron transfer (ET) by coupling vibrations of the heme directly to vibrations of the pp at the protein - protein interface. This could allow for the direct transduction of the thermal (vibrational) energy from the protein surface to the heme that is released on protein/protein complex formation, or it could modulate the heme vibrations in the protein/protein complex to minimize reorganization energy. Both mechanisms lower energy barriers for ET. Notably, the conformation of the distal Met side chain is fine-tuned in the protein to localize heme-pp mixed vibrations within the 250-to 400-cm-1 spectral region. These findings point to a particular orientation of the distal Met that maximizes ET

Cyanoprocaryota of Tubalskyi Estuary (Azov sea basin)

Information about species composition of Cyanoprocaryota representatives in the natural boundary of Tubalskyi Estuary within Pryazov National Natural Park is supplemented. Taxonomic structure of identified algae species is given, the data about occurrence of species in different habitats within national park is provided. We present a systematic structure and geographical affinity of discovered algae species. We registered 38 species of cyanoprocaryotic algae of orders: Chroococcales, Oscillatoriales and Nostocales with predominance of Oscillatoriales representatives in different habitats of Tubalskyi Estuary within the areas of Pryazov National Natural Park. The greatest number of algae species had genera Lyngbya, Phormidium, Microcoleus Leptolyngbya – 4 species per each genera. The majority of algae species were the cosmopolitans. Microcoleus tenerrimus was registered in all the studied plots of soil sampling and in the water reservoir of Tubalskyi Estuary. The most abundant and distributed species was Lyngbya aestuarii, which formed the macroscopic growths (cyanobacterial mats)