Effects of carbon and silicon nanotubes and carbon nanofibers on marine microalgae Heterosigma akashiwo.

The effect of carbon and silicon nanotubes (CNTs and SiNTs) and carbon nanofibers (CNFs) to microscopic marine algae Heterosigma akashiwo was studied, using algal growth inhibition for 3 days (acute effect) and 7 days (chronic effect) as toxicity endpoints. The criterion of the toxic effect was the statistically significant reduction of the number of algal cells in the exposed samples compared to the control. Samples did not demonstrate toxic effects at doses 1 mg/l and 10 mg/l. CNTs and SiNTs samples at 100 mg/l exhibited both acute and chronic toxic effects. We assume that the main cause of cell death in these samples was related to the mechanical damage of cell integrity. CNFs at concentrations of 100 mg/l did not inhibit algal growth, but cells with irregular shapes were observed, which were not observed after exposure to CNTs and SiNTs. Nickel impurities present in CNFs samples are presumably the main cause of observed cell deformations.

Glycosidases of marine organisms.

This review discusses the catalytic properties, activity regulation, structure, and functions of O-glycoside hydrolases from marine organisms exemplified by endo-1→3-ß-D-glucanases of marine invertebrates.

Effects of multiwalled carbon nanotubes received orally during 6 days on the gastrointestinal tract.

The effects of multiwalled carbon nanotubes on epitheliocytes of different compartments of the gastrointestinal tract and urothelium of different compartments of the renal nephron were studied in CBA mice. The nanotubes affected mouse gastrointestinal mucosa and renal urothelium. The cell reaction in the macula densa of the renal distal tubules and the immune system reaction to oral nanotubes were detected. A possible effect of nanotubes administered orally on the renal filtration function was hypothesized.

Catalytic properties and amino acid sequence of endo-1→3-ß-D-glucanase from the marine mollusk Tapes literata.

A specific 1→3-ß-D-glucanase with molecular mass 37 kDa was isolated in homogeneous state from crystalline style of the commercial marine mollusk Tapes literata. It exhibits maximal activity within the pH range from 4.5 to 7.5 at 45°C. The 1→3-ß-D-glucanase catalyzes hydrolysis of ß-1→3 bonds in glucans as an endoenzyme with retention of bond configuration, and it has transglycosylating activity. The K(m) for hydrolysis of laminaran is 0.25 mg/ml. The enzyme is classified as a glucan endo-(1→3)-ß-D-glucosidase (EC 3.2.1.39). The cDNA encoding this 1→3-ß-D-glucanase from T. literata was sequenced, and the amino acid sequence of the enzyme was determined. The endo-1→3-ß-D-glucanase from T. literata was assigned to the 16th structural family (GHF 16) of O-glycoside hydrolases.

Polyphenols of Perilla frutescens of the family Lamiaceae identified by tandem mass spectrometry.

Perilla frutescens is mainly cultivated as an oilseed crop. Perilla seeds contain 40-53 % of oil, 28 % of protein. The growing season is 100-150 days. In Russia, perilla is grown in the Far East, where the yield is 0.8-1.2 t/ha. Perilla of different geographical origin has its own special, sharply different features that characterize two geographical groups: Japanese and Korean-Chinese. These groups differ from each other in the length of the growing season, the height of plants, the color of the stem, the surface and the size of the leaves, the shape of the bush, the shape and size of the inflorescences, the size of the cups, the size and color of the seeds. P. frutescens contains a large number of polyphenolic compounds that are biologically active components. The purpose of this research was a metabolomic study of extracts from leaves of P. frutescens obtained from the collection of Federal Research Center the N.I. Vavilov All-Russian Institute of Plant Genetic Resources, grown on the fields of the Far East Experiment Station - Branch of Federal Research Center (Primorsky Krai, Russia). To identify target analytes in extracts, HPLC was used in combination with an ion trap. Preliminary results showed the presence of 23 biologically active compounds corresponding to P. frutescens. In addition to the reported metabolites, a number of metabolites were newly annotated in P. frutescens. There were hydroxycoumarin Umbelliferone; triterpene Squalene; omega-3 fatty acid Stearidonic [Moroctic] acid; higher-molecular-weight carboxylic acid: Tetracosenoic acid and Salvianic acid C; lignan Syringaresinol and cyclobutane lignan Sagerinic acid, etc. A wide range of biologically active compounds opens up rich opportunities for the creation of new drugs and dietary supplements based on extracts of perilla of the family Lamiaceae, subfamily Lamioideae, tribe Satureji and subtribe Perillinae.

[Catalytic properties of endo-1,3-beta-D-glucanase from the Vietnamese edible mussel Perna viridis].

A beta-1,3-glucanase with a molecular mass of 33 kDa was isolated in the homogeneous state from a crystalline stalk of the commercially available Vietnamese edible mussel Perna viridis. It hydrolyzes beta-1,3-bonds in glucans and is capable of catalyzing the transglycosylation reaction. The beta-1,3-glucanase has a K(m) value of 0.3 mg/ml for the hydrolysis of laminaran and shows a maximum activity in the pH range from 4 to 6.5 and at 45 degrees C. Its half-inactivation time is 180 min at 45 degrees C and 20 min at 50 degrees C. The enzyme was ascribed to glucan-endo-(1-3)-beta-D-glucosidases (EC 3.2.1.39). The enzyme could be used in the structure determination of beta-1,3-glucans and enzymatic synthesis of new carbohydrate-containing compounds.

Toxicity bioassay of waste cooking oil-based biodiesel on marine microalgae.

The world biodiesel production is increasing at a rapid rate. Despite its perceived safety for the environment, more detailed toxicity studies are mandatory, especially in the field of aquatic toxicology. While considerable attention has been paid to biodiesel combustion emissions, the toxicity of biodiesel in the aquatic environment has been poorly understood. In our study, we used an algae culture growth-inhibition test (OECD 201) for the comparison of the toxicity of B100 (pure biodiesel), produced by methanol transesterification of waste cooking oil (yellow grease), B0 (petroleum diesel fuel) and B20 (diesel-biodiesel blended of 20% biodiesel and 80% petroleum diesel fuel by volume). Two marine diatoms Attheya ussuriensis and Chaetoceros muelleri, the red algae Porphyridium purpureum and Raphidophyte Heterosigma akashiwo were employed as the aquatic test organisms. A sample of biodiesel from waste cooking oil without dilution with petroleum diesel (B100) showed the highest level of toxicity for the microalgae A. ussuriensis, C. muelleri and H. akashiwo, compared to hexane, methanol, petroleum diesel (B0) and diluted sample (B20). The acute EC50 in the growth-inhibition test (96 h exposure) of B100 for the four species was in the range of 3.75-23.95 g/L whereas the chronic toxicity EC50 (7d exposure) was in the range of 0.42-16.09 g/L.

Morphological and chemical composition of particulate matter in buses exhaust.

This research article investigates the particulate matter originated from the exhaust emissions of 20 bus models, within the territory of Vladivostok, Russian Federation. The majority of evaluated buses (17 out of 20) had emissions of large particles with sizes greater than 400 µm, which account for more than 80% of all measured particles. The analysis of the elemental composition showed that the exhaust emissions contained Al, Cd, Cu, Fe, Mg, Ni, Pb, and Zn, with the concentration of Zn prevailing in all samples by two to three orders of magnitude higher than the concentrations of the other elements.

Morphologic and chemical composition of particulate matter in motorcycle engine exhaust.

Despite the fact that environmental pollution due to motorcycle exhaust gases reports a great increase, motorcycle production exhibits a great increase through the last years. Countries of Asia and Africa are reported to be the major regions where two-wheeled vehicles are a major transportation mode, with tens of millions of units sold per year. Motorcycle exhaust particles are considered to be the major contributor to environmental pollution due to their airborne dispersion, containing great amount of polycyclic aromatic hydrocarbons (PAHs). This study aims at reporting an objective analysis of the main sources of the ambient air pollution as also particle size distribution and chemical composition analysis of particulate matter originated from the exhausts of two-wheeled vehicles used in the territory of Vladivostok, Russia. Various types of two-wheeled vehicles were examined (motorcycles, ATVs, scooters and wet bikes) using different types of engine and fuel system. Experimental results showed that there was no clear relation to the particle size distribution with the engine displacement of motorcycle and the number of strokes and the fuel system. Instead, there were reported two clear assumptions. The first one is that regarding to the motorcycle brand, a few samples did not exhibit a great percentage of PM10 fraction. The second one is that more modern vehicles, that have a harmful gas afterburning system, are usually the source of an increased percentage of PM10 emitted particles. At last, it should be mentioned that the laser particle size analysis method is capable of determining the particle sizes after their agglomeration whereas the optical morphometry method allows to determine the real particle size of emissions. In conclusion, it can be pointed out that the agglomeration of particles can lead to the reduction in the toxicity of particles emissions originated from two wheeled-vehicles.

Characterization of fume particles generated during arc welding with various covered electrodes.

Arc welding operations are considered to be risky procedures by generating hazardous welding fume for human health. This study focuses on the key characteristics, as well as dispersion models, of welding fumes within a work zone. Commercial and widely used types of electrodes with various types of covering (rutile, basic, acidic and rutile-cellulose) were used in a series of experiments on arc welding operations, under 100 and 150 amps of electric current. According to the results of this study, maximum levels of pollution with particles of PM10 fraction occur in the workspace during arc welding operations. Disregarding the types of electrodes used, the 3D models of dispersion of the РМ10 particles at the floor plane exhibit corrugated morphologies while also demonstrate high concentrations of the РМ10 particles at distances 0-3 m and 4-5 m from the emission source. The morphology of these particles is represented by solid and hollow spheres, 'nucleus-shell' structures, perforated spheres, sharp-edged plates, agglomerates of the tree-like (coral) shape. At last the bifractional mechanism of fume particle formation for this type of electrodes is also shown and described. In this article results are reported, which demonstrate the hazards of the arc welding process for human health. The results of the characterization of WFs reported improve our understanding of risks that these operations pose to human health and may strengthen the need for their control and mitigation.

Biochemical Content of Cambium of Abies nephrolepis Eaten by Bears on the Far East of Russia.

The peculiarity of bears behavior of stripping of bark is typical for all species. We have described the damage to trees, by Asiatic black bear (Ursus thibetanus) and brown bear (U. arctos) in Primorsky Krai and by brown bears on the Sakhalin Island during 1998-2015. In this study, we studied the damaged bark of the tree only in cases where it was clear that part of the cambium was eaten by bears. Cambium of species Abies nephrolepis is the most preferred for bear consumption in Primorsky Krai. We distinguished very large seasonal fluctuations in the amount of its consumption. The greatest interest of bears in this kind of food is in the summer time. We have analyzed the composition of the cambium of A. nephrolepis. These results suggest that the important purpose of the use of this kind of food is to restore and maintain the normal functioning of the intestines.