New data on the flora of diatom algae (Centrophyceae) in waterbodies of Sakhalin Island

The first studies of phytoplankton in inland waterbodies of Sakhalin Island by electron microscopy have revealed 19 representatives of the class Centrophyceae, including some that are new for the flora of the region (Aulacoseira subarctica, Coscinodiscopsis commutata, Stephanodiscus delicatus, S. makarovae, Thalassiosira baltica, and T. cf. hyalina). Species of centric diatoms that are new for these waterbodies have been documented in lakes Vavaiskiye and Tunaicha, and the species composition of Centrophyceae have been revised. The first complete data on the taxonomical spectrum of Centrophyceae in Lake Sladkoye, lakes of Mount Spamberg, and the Tym River have been obtained. A revision of the species composition of Centrophyceae in the waterbodies of Sakhalin Island has been made, and the list of the class has been broadened to 44 taxa from 17 genera.     

Reversible metabolic depression in lamprey hepatocytes during prespawning migration: dynamics of mitochondrial membrane potential

The lamprey (Lampetra fluviatilis L.) is an extant representative of the ancient vertebrate group of Agnathans. During the prespawning migration (the river period of life from autumn until spring) lamprey hepatocytes exhibit widely different energy states: a high-energy state in autumn and spring, corresponding to a normal physiological standard, and a low-energy state in winter, which is provoked by prolonged starvation and profound metabolic arrest. In spring the restoration of energy status (return to an active state) is associated with hormonally induced lipolysis of the lipid droplets stored in the cells. Lamprey hepatocytes demonstrate an aerobic metabolism based on oxidation of free fatty acids. The dynamics of mitochondrial membrane potential (MMP) were measured throughout the prespawning migration. Pharmacological inhibition of the electron transport chain decreased the MMP and caused extensive depletion of cellular ATP without loss of cell viability. The potential molecular mechanisms responsible for winter metabolic depression in lamprey hepatocytes are discussed.     

Antioxidant Properties of Galanin and Its N-Terminal Fragments in in vitro and in vivo Oxidative Stress Modeling

Biochemistry (Moscow) - Antioxidant properties of rat galanin GWTLNSAGYLLGPHAIDNHRSFSDKHGLT-NH2 (Gal), N-terminal fragment of galanin (2-15 aa) WTLNSAGYLLGPHA (G1), and its modified analogue...     

Microbial Biofilms in the Proshchal’naya Karst Cave (Far East,Russia)

Microbiology - Effect of abiotic (composition of drip and fracture water) and biotic factors (composition and activity of microbial complexes) on biofilm formation in the Proshchal’naya karst...     

Methylcatechol 1,2-dioxygenase of <Emphasis Type="Italic">Rhodococcus opacus</Emphasis> 6a is a new type of the catechol-cleaving enzyme

The strains Rhodococcus sp. 400, R. rhodochrous 172, and R. opacus 6a utilize 4-methylbenzoate as the only carbon and energy source. 4-Methylcatechol is a key intermediate of biodegradation. Its further conversion by all the strains proceeds via ortho-cleavage. The specific activity of catechol 1,2-dioxygenase assayed in crude extracts of Rhodococcus sp. 400 and R. rhodochrous 172 with 3- and 4-methylcatechols does not exceed the enzyme activity assayed with catechol. Two catechol 1,2-dioxygenases have been purified from the biomass of R. opacus strain 6a grown with 4-methylbenzoate. These enzymes differed in molecular mass and physicochemical and catalytic properties. One of these enzymes belongs to the type of enzymes cleaving the catechol ring and known as methylcatechol 1,2-dioxygenases. In bacteria of the Rhodococcus genus, such an enzyme is described here for the first time.     

Age Dynamics of Helminth Fauna in Longfin Baikal Sculpin Cottocomephorus inermis (Cottidae)

Journal of Ichthyology - This is the first report on the infection of longfin Baikal sculpin Cottocomephorus inermis of Barguzinsky Bay (Lake Baikal) by helminths. A total of eight species of...     

Isolation and preliminary characterization of carotenoids from pink-pigmented methylotrophs

An effective method was developed for complete removal of pigments from the cells and solvent mixture for further separation of pigments using thin layer chromatography on silica gel. Carotenoid samples that have been obtained in this way are of good purity for further investigations. Carotenoid pigments of pink-pigmented facultative methylotrophic bacteria Methylobacterium have been characterized. These carotenoids are represented mainly by xanthophylls, particularly hydroxycarotenoids. Strains M. fujisawaense B-3365 and M. mesophilicum B-3352 also have nonpolar carotenes in a small amount. Physico-chemical properties of carotenoids have been studied.     

Seasonal dynamics of phytoplankton in a lagoon-type lake Izmenchivoye (Southeast Sakhalin)

The seasonal changes in taxonomic structure, dynamics of number, and biomass of phytoplankton in the Izmenchivoye lagoon lake (southeast Sakhalin) were studied. In all, 266 species and intraspecies taxa of microalgae were revealed. The greatest species diversity (according to the Shannon index) was observed in May, August and October (H = 2.76–2.89), the least (H = 0.5–0.86), in April and January of 2006. The monthly average number varied from 997 up to 84 282 cells/l, and biomass from 18.98 up to 878.62 mg/m³. The average annual number of phytoplankton and its biomass were 32 650 cells/l and biomass 172.13 mg/m³ respectively. The maximum number was registered in August, 2005, and maximum biomass was recorded in January, 2006. Winter, spring and summer peaks of number coinciding with those of biomass were registered. For the first time, winter bloom of phytoplankton was registered in inland waters of the Sakhalin Island. In the winter and spring the basic input to formation of the parameters was composed of diatoms; in summer and autumn it was composed of by flagellates (dinophyta and cryptophyta).