Photosynthesis and primary production in Lake Kasumigaura (Japan) monitored monthly since 1981

This study reports the primary production of phytoplankton determined with a ¹³C tracer, and their related variables, in Lake Kasumigaura, a shallow, hyper-eutrophic lake, and the second largest lake in Japan. Measurements were conducted monthly from August 1981 to December 2013 at four stations within the lake. Monitoring was a component of the Lake Kasumigaura Long-term Environmental Monitoring program, conducted by the National Institute for Environmental Studies (NIES) since 1977. The program collects data on water quality, and plankton and benthic communities. Lake Kasumigaura is registered as a core site of the Japan Long-term Ecological Research Network (JaLTER), which is a member of the International Long-term Ecological Research Network (ILTER). This dataset includes daily primary production (Pzd gC m^?2 d^?1) and the six parameters required to calculate Pzd: maximum photosynthesis rate (P _max gC gC^?1 h^?1); light irradiance at the junction of the initial slope (α (gC gC^?1 h^?1) (μmol photon m^?2 s^?1)^?1) and P _max of the photosynthesis vs. irradiance (P vs. E) curve (E _k μmol photon m^?2 s^?1); attenuation coefficient of photosynthetically available radiation (PAR) (K _PAR m^?1); water depth at each sampling station (Z _b , m); dissolved inorganic carbon (DIC mgC L^?1) and particulate organic carbon concentrations (POC gC m^?3); and chlorophyll a amounts (Chl.a μg L^?1). Daily primary production was calculated by obtaining a P vs. E curve over a short-term incubation (approximately 1 h) in a water tank using in situ water temperature in the laboratory, based on the field conditions of the sampling date. The dataset has been used for ecological studies as well as for management studies on water quality and ecosystems. This dataset is unique among the available published papers concerning lakes or primary production in various ecosystems, collected over a long period of time and freely available.     

Phylogeography of mitochondrial DNA in South Asian Dolly Varden char <Emphasis Type="Italic">Salvelinus curilus</Emphasis> Pallas, 1814 (Salmoniformes,Salmonidae): Mediated gene introgression?

In 41 individuals of South Asian Dolly Varden char Salvelinus curilus, nucleotide sequences of tRNA-Pro gene fragment (27 bp) and mtDNA control region (483–484 bp) were analyzed. The fish were collected in 20 localities covering virtually the whole range of the species: Kuril Islands, Sakhalin Island, and Primorye. In addition, six individuals of three other char species (S. albus, S. malma, and S. leucomaenis), which are closely related to S. curilus and inhabit the Russian Far East, were examined. In all, we detected 12 different variants of mtDNA haplotypes that formed three distinct groups differing in 14–20 nucleotide positions. The first group consisted of six haplotypes found in S. curilus in Kuril Islands, Sakhalin, and Primorye (mtDNA phylogroup OKHOTSKIA). The second group comprised four haplotypes representing the mtDNA phylogroup BERING, which had been described earlier (Brunner et al, 2001); they were found in S. curilus in Kuril Islands and Sakhalin, as well as in S. albus and S. malma in Kamchatka and northern Kurils. The third group included two haplotypes detected in S. leucomaenis. The existence of two mtDNA lineages (OKHOTSKIA and BERING) in S. curilus from Kurils and Sakhalin was explained by hybridization and mtDNA transfer from S. malma to S. curilus. The absence of the BERING haplotypes in S. curilus from Primorye water reservoirs is related to the physical isolation of the Sea of Okhotsk and Sea of Japan basins in past epochs. On the basis of comparing phylogenetic trees, constructed from the data on allozyme and mtDNA variation, we suggest that in this case, a mediated transfer of mtDNA in Alpinoid chars → S. malma → S. curilus chain could occur.     

Natively oxidized amino acid residues in the spinach cytochrome <Emphasis Type="Italic">b</Emphasis><Subscript><Emphasis Type="Italic">6</Emphasis></Subscript><Emphasis Type="Italic">f</Emphasis> complex

The cytochrome b ₆ f complex of oxygenic photosynthesis produces substantial levels of reactive oxygen species (ROS). It has been observed that the ROS production rate by b ₆ f is 10–20 fold higher than that observed for the analogous respiratory cytochrome bc₁ complex. The types of ROS produced (O₂^{??, 1}O₂, and, possibly, H₂O₂) and the site(s) of ROS production within the b ₆ f complex have been the subject of some debate. Proposed sources of ROS have included the heme b _p , PQ _p ^?? (possible sources for O₂^??), the Rieske iron–sulfur cluster (possible source of O₂^?? and/or ¹O₂), Chl a (possible source of ¹O₂), and heme c _n (possible source of O₂^?? and/or H₂O₂). Our working hypothesis is that amino acid residues proximal to the ROS production sites will be more susceptible to oxidative modification than distant residues. In the current study, we have identified natively oxidized amino acid residues in the subunits of the spinach cytochrome b ₆ f complex. The oxidized residues were identified by tandem mass spectrometry using the MassMatrix Program. Our results indicate that numerous residues, principally localized near p-side cofactors and Chl a, were oxidatively modified. We hypothesize that these sites are sources for ROS generation in the spinach cytochrome b ₆ f complex.     

Fish assemblage structure in an estuary of the Atlantic Forest biodiversity hotspot (southern Brazil)

We described the fish assemblage in the estuary of the Guaraguaçu River (one of the largest tributaries of the Paranaguá Bay Estuary, located within Brazil’s Atlantic Forest Biosphere Reserve) from June 2005 to May 2006, and assessed the seasonal and spatial effects of abiotic environmental attributes on the fish assemblage structure. Despite some oscillations in salinity, the upper and lower estuaries had year-round persistent oligohaline and polyhaline conditions, respectively. Despite high species richness (55 species), the Guaraguaçu River Estuary fish community contains a few dominant taxa; 11% of the richness accounts for >60% of its density and biomass. The most abundant species (in terms of both biomass and density) was Atherinella brasiliensis. Species whose densities were most strongly associated with the upper estuary were Centropomus parallelus, Ctenogobius schufeldti, Eucinostomus melanopterus, Platanichthys platana, Trinectes paulistanus, and Eugerres brasilianus. Those whose densities were most strongly associated with the lower estuary were A. brasiliensis, Sphoeroides greeleyi, Eucinostomus argenteus, Sphoeroides testudineus, Diapterus rhombeus, and Harengula clupeola. Throughout the year, canonical correspondence analysis identified: (1) the pattern of horizontal stratification of salinity along the river as being the most important variable for explaining most of the fish fauna structure; and (2) a strong relationship between the fish fauna and the salinity gradient along the estuary. Analysis of similarity further confirmed that each estuarine zone supports a year-round persistent and relatively homogeneous fish species assemblage. Total mean density and biomass remained constant over time in each estuarine habitat, but density shifted in the most abundant species, which appears related to recruitment patterns. Such species and abundance persistence likely occurs because seasonal rainfall-induced changes in river discharge are not sufficient to significantly shift runoff and salinity and thus fish assemblage structure (species composition, density and biomass) along the estuary. Such a lack of seasonal fish fauna movement as a response to changes in river flow contrasts with other estuarine systems around the world.     

Modelling photosynthesis in shallow algal production ponds

Shallow ponds with rapidly photosynthesising cyanobacteria or eukaryotic algae are used for growing biotechnology feedstock and have been proposed for biofuel production but a credible model to predict the productivity of a column of phytoplankton in such ponds is lacking. Oxygen electrodes and Pulse Amplitude Modulation (PAM) fluorometer technology were used to measure gross photosynthesis (P _G) vs. irradiance (E) curves (P _G vs. E curves) in Chlorella (chlorophyta), Dunaliella salina (chlorophyta) and Phaeodactylum (bacillariophyta). P _G vs. E curves were fitted to the waiting-in-line function [P _G = (P _Gmax × E/E_opt) × exp(1 — E/E_opt)]. Attenuation of incident light with depth could then be used to model P _G vs. E curves to describe P _G vs. depth in pond cultures of uniformly distributed planktonic algae. Respiratory data (by O2-electrode) allowed net photosynthesis (P _N) of algal ponds to be modelled with depth. Photoinhibition of photosynthesis at the pond surface reduced P _N of the water column. Calculated optimum depths for the algal ponds were: Phaeodactylum, 63 mm; Dunaliella, 71 mm and Chlorella, 87 mm. Irradiance at this depth is ≈ 5 to 10 μmol m^?2 s^?1 photosynthetic photon flux density (PPFD). This knowledge can then be used to optimise the pond depth. The total net P _N [μmol(O2) m^?2 s^?1] were: Chlorella, ≈ 12.6 ± 0.76; Dunaliella, ≈ 6.5 ± 0.41; Phaeodactylum ≈ 6.1 ± 0.35. Snell’s and Fresnel’s laws were used to correct irradiance for reflection and refraction and thus estimate the time course of P _N over the course of a day taking into account respiration during the day and at night. The optimum P _N of a pond adjusted to be of optimal depth (0.1–0.5 m) should be approximately constant because increasing the cell density will proportionally reduce the optimum depth of the pond and vice versa. Net photosynthesis for an optimised pond located at the tropic of Cancer would be [in t(C) ha^?1 y^?1]: Chlorella, ≈ 14.1 ± 0.66; Dunaliella, ≈ 5.48 ± 0.39; Phaeodactylum, ≈ 6.58 ± 0.42 but such calculations do not take weather, such as cloud cover, and temperature, into account.     

Computational design of zinc-ion-responsive two-photon fluorescent probes with conjugated multi-structures

A series of conjugated multi-structured fluorescent probe molecules based on a salen ligand were designed and investigated in dimethyl sulfoxide solvent using a quantum-chemical method. The results indicate that the one-photon absorption and fluorescence emission spectra (λ ^O and λ ^EM) of these molecules generally show redshifts (of 23.1–74.5 and 22.7–116.6 nm, respectively) upon the coordination of the molecules to Zn²⁺. Large Stokes shifts (1511.2–11744.1 cm^?1) were found for the molecules, meaning that interference between λ ^O and λ ^EM can be avoided for these molecules. The two-photon absorption spectra of the molecules usually present blueshifts, but the two-photon absorption cross-section (δ) greatly increases (by 221.5–868.0 GM) upon the coordination of the molecules with Zn²⁺. Most of the molecules show strong two-photon absorption peaks in the range 678.2–824.4 nm, i.e., in the near-infrared region. In a word, the expanded π-conjugated frameworks of these molecules lead to redshifted λ ^O and λ ^EM and enhanced δ values. Moreover, (L-phenyl)?₂ and (L-phenyl-ethynyl)₂ are the most suitable of the multi-structured molecules examined in this work for use as two-photon fluorescent probes for zinc ion detection in vivo.

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Graphical Abstract Scheme of the calculated transition energies (E_0k and E_0n) and the transition dipole moments (M_0k and M_kn). NTO 109, NTO 197 and NTO 228 of Zn(L-phenyl-ethynyl), Zn₂(L-phenyl-ethynyl)₂ and Zn₃(L-phenyl)₃ for one-photon  absorption, respectively.

     

<Emphasis Type="Italic">glyA</Emphasis> gene knock-out in <Emphasis Type="Italic">Escherichia coli</Emphasis> enhances L-serine production without glycine addition

In E. coli, glyA encodes for serine hydroxymethyltransferase (SHMT), which converts L-serine to glycine. When engineering L-serine-producing strains, it is therefore favorable to inactivate glyA to prevent L-serine degradation. However, most glyA knockout strains exhibit slow cell growth because of the resulting lack of glycine and C₁ units. To overcome this problem, we overexpressed the gcvTHP genes of the glycine cleavage system (GCV), to increase the C₁ supply before glyA was knocked out. Subsequently, the kbl and tdh genes were overexpressed to provide additional glycine via the L-threonine degradation pathway, thus restoring normal cell growth independent of glycine addition. Finally, the plasmid pPK10 was introduced to overexpress pgk, serA ^Δ197 , serC and serB, and the resulting strain E4G2 (pPK10) accumulated 266.3 mg/L of L-serine in a semi-defined medium without adding glycine, which was 3.18-fold higher than the production achieved by the control strain E3 (pPK10). This strategy can accordingly be applied to disrupt the L-serine degradation pathway in industrial production strains without causing negative side-effects, ultimately making L-serine production more efficient.     

Vegetation of the <Emphasis Type="Italic">Hydrochari-Lemnete</Emphasis> and <Emphasis Type="Italic">Potametea</Emphasis> classes in the Danube-Tisza-Danube hydrosystem (Serbia)

Aquatic vegetation of Hydrochari-Lemnetea and Potametea classes in the Danube-Tisza-Danube hydrosystem (Hs DTD) was studied in 2009–2012, by applying the standard Braun-Blanquet method. The canal network vegetation comprises 14 associations, with Trapetum natantis and Ceratophylletum demersi being the most widely distributed. Hs DTD is also a habitat for several important endangered species, which serve as edificators of the following phytocenoses: Nymphaeetum albae, Nymphaeetum albo-luteae, Nymphoidetum peltatae, Trapetum natantis, Lemno-Spirodeletum, Salvinio-Spirodeletum polyrrhizae, Lemno-Utricularietum vulgaris, Potametum nodosi, Myriophyllo-Potametum and Najadetum marinae. In the studied vegetation, we also found an invasive phytocenosis Elodeetum canadensis that did not have an expanding tendency, and Ceratophyllo demersi-Vallisnerietum spiralis that had this tendency, which made monitoring its stands necessary. Physico-chemical analyses of water, conducted at localities in which the studied phytocenoses thrive, revealed that the development and distribution of most phytocenoses is closely linked with specific habitat conditions. Among the studied parameters, the most significant for the phytocenoses differentiation were: pH, alkalinity, COD-MnO₄, BOD₅, NO ₃ ^? , NO ₂ ^? , PO ₄ ^3? and the concentration of total phosphorus.     

Analysis of applicability of triplet-state emission of molecular hydrogen for spectral diagnostics of a DC discharge

The applicability of emission of the N ³Λ_σ triplet states of molecular hydrogen for spectral diagnostics of the positive column of a dc glow discharge in hydrogen at translational gas temperatures of 360–600 K, specific absorbed powers of 0.8–4.25 W/cm, gas pressures of p = 0.3–15.0 Torr, reduced fields of E/N = 30–130 Td, and electron densities of n _e = 4.0 × 10⁹–6.5 × 10¹⁰ cm^–3 is analyzed by using an advanced level-based semi-empirical collisional?radiative model. It is found that secondary processes make the main contribution to the population and decay of the N ³Λ_σ = a ³Σ⁺ _g , c ³Π _u , g ³Σ⁺ _g , h ³Σ⁺ _g , and i ³Π _g triplet states. The dipole-allowed transitions e ³Σ⁺ _g → a ³Σ⁺ _g , f ³Σ⁺ _g → a ³Σ⁺ _g , g ³Σ⁺ _g and k ³Π _u → a ³Σ⁺ _g can be used for spectral diagnostics of a dc discharge within a simplified coronal model.     

Assessment of photosynthetic potential of indoor plants under cold stress

Photosynthetic parameters including net photosynthetic rate (P_N), transpiration rate (E), water-use efficiency (WUE), and stomatal conductance (g_s) were studied in indoor C₃ plants Philodendron domesticum (Pd), Dracaena fragans (Df), Peperomia obtussifolia (Po), Chlorophytum comosum (Cc), and in a CAM plant, Sansevieria trifasciata (St), exposed to various low temperatures (0, 5, 10, 15, 20, and 25°C). All studied plants survived up to 0°C, but only St and Cc endured, while other plants wilted, when the temperature increased back to room temperature (25°C). The P_N declined rapidly with the decrease of temperature in all studied plants. St showed the maximum P_N of 11.9 μmol m^?2 s^?1 at 25°C followed by Cc, Po, Pd, and Df. E also followed a trend almost similar to that of P_N. St showed minimum E (0.1 mmol m^?2 s^?1) as compared to other studied C₃ plants at 25°C. The E decreased up to ≈4-fold at 5 and 0°C. Furthermore, a considerable decline in WUE was observed under cold stress in all C₃ plants, while St showed maximum WUE. Similarly, the g_s also declined gradually with the decrease in the temperature in all plants. Among C₃ plants, Pd and Po showed the maximum g_s of 0.07 mol m^?2 s^?1 at 25°C followed by Df and Cc. However, St showed the minimum g_s that further decreased up to ～4-fold at 0°C. In addition, the content of photosynthetic pigments [chlorophyll a, b, (a+b), and carotenoids] was varying in all studied plants at 0°C. Our findings clearly indicated the best photosynthetic potential of St compared to other studied plants. This species might be recommended for improving air quality in high-altitude closed environments.     

Nitrogen Metabolism Genes from Temperate Marine Sediments

In this study, we analysed metagenomes along with biogeochemical profiles from Skagerrak (SK) and Bothnian Bay (BB) sediments, to trace the prevailing nitrogen pathways. NO₃ ^? was present in the top 5 cm below the sediment-water interface at both sites. NH₄ ⁺ increased with depth below 5 cm where it overlapped with the NO₃ ^? zone. Steady-state modelling of NO₃ ^? and NH₄ ⁺ porewater profiles indicates zones of net nitrogen species transformations. Bacterial protease and hydratase genes appeared to make up the bulk of total ammonification genes. Genes involved in ammonia oxidation (amo, hao), denitrification (nir, nor), dissimilatory NO₃ ^? reduction to NH₄ ⁺ (nfr and otr) and in both of the latter two pathways (nar, nap) were also present. Results show ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) are similarly abundant in both sediments. Also, denitrification genes appeared more abundant than DNRA genes. 16S rRNA gene analysis showed that the relative abundance of the nitrifying group Nitrosopumilales and other groups involved in nitrification and denitrification (Nitrobacter, Nitrosomonas, Nitrospira, Nitrosococcus and Nitrosomonas) appeared less abundant in SK sediments compared to BB sediments. Beggiatoa and Thiothrix 16S rRNA genes were also present, suggesting chemolithoautotrophic NO₃ ^? reduction to NO₂ ^? or NH₄ ⁺ as a possible pathway. Our results show the metabolic potential for ammonification, nitrification, DNRA and denitrification activities in North Sea and Baltic Sea sediments.     

Enhanced succinic acid productivity by expression of <Emphasis Type="Italic">mgtCB</Emphasis> gene in <Emphasis Type="Italic">Escherichia coli</Emphasis> mutant

In this study, a novel engineering Escherichia coli strain (CBMG111) with the expression of mgtCB gene was constructed for the enhanced fermentative production of succinic acid by utilizing the synergetic effect of mgtC gene to improve the growth of strains at the environment of low Mg²⁺ concentration and mgtB to enhance the transport of Mg²⁺ into cells. After the effect of the expression of the individual genes (mgtA, mgtB, mgtC) on the growth of E. coli was clarified, the fermentative production of succinic acid by CBMG111 was studied with the low-price mixture of Mg(OH)₂ and NH₃·H₂O as the alkaline neutralizer and the biomass hydrolysates as the carbon sources, which demonstrated that the expression of mgtCB gene can significantly increase the productivity of succinic acid (2.97 g L^?1 h^?1) compared with that by using the engineering strain with the overexpression of mgtA gene.     

Evaluation of growth and phycobiliprotein composition of cyanobacteria isolates cultivated in different nitrogen sources

Phycobiliproteins, light-harvesting pigments found in cyanobacteria and in some eukaryotic algae, have numerous commercial applications in food, cosmetic, and pharmaceutical industries. Colorant production from cyanobacteria offers advantages over their production from higher plants, as cyanobacteria have fast growth rate and high photosynthetic efficiency and require less space. In this study, three cyanobacteria strains were studied for phycobiliprotein production and the influence of sodium nitrate, potassium nitrate and ammonium chloride on the growth and phycobiliprotein composition of the strains were evaluated. In the batch culture period of 12 days, Phormidium sp. and Pseudoscillatoria sp. were able to utilize all tested nitrogen sources; however, ammonium chloride was the best nitrogen source for both strains to achieve maximum growth rate μ?=?0.284?±?0.03 and μ?=?0.274?±?0.13 day^?1, chlorophyll a 16.2?±? 0.5 and 12.2?±? 0.2 mg L^?1, and phycobiliprotein contents 19.38?±?0.09 and 19.99?±?0.14% of dry weight, whereas, for Arthrospira platensis, the highest growth rate of μ?=?0.304?±?0.0 day^?1, chlorophyll a 19.1?±?0.5 mg L^?1, and phycobiliprotein content of 22.27?±?0.21% of dry weight were achieved with sodium nitrate. The phycocyanin from the lyophilized cyanobacterial biomass was extracted using calcium chloride and food grade purity (A₆₂₀/A₂₈₀ ratio >?0.7) was achieved. Furthermore, phycocyanin was purified using two-step chromatographic method and the analytical grade purity (A₆₂₀/A₂₈₀ ratio >?4) was attained. SDS-PAGE demonstrated the purity and presence of two bands corresponding to α- and β-subunits of the C-phycocyanin. The results showed that Phormidium sp. and Pseudoscillatoria sp. could be good candidates for phycocyanin production.     

Toxin Gene Contents and Activity of <Emphasis Type="Italic">Bacillus thuringiensis</Emphasis> Strains Against Two Sugarcane Borer Species, <Emphasis Type="Italic">Diatraea saccharalis</Emphasis> (F.) and <Emphasis Type="Italic">D. flavipennella</Emphasis> (Box)

Bacillus thuringiensis (Berliner) bears essential characteristics in the control of insect pests, such as its unique mode of action, which confers specificity and selectivity. This study assessed cry gene contents from Bt strains and their entomotoxicity against Diatraea saccharalis (F.) and Diatraea flavipennella (Box) (Lepidoptera: Crambidae). Bioassays with Bt strains were performed against neonates to evaluate their lethal and sublethal activities and were further analyzed by PCR, using primers to identify toxin genes. For D. saccharalis and D. flavipennella, 16 and 18 strains showed over 30% larval mortality in the 7th day, respectively. The LC₅₀ values of strains for D. saccharalis varied from 0.08 × 10⁵ (LIIT-0105) to 4104 × 10⁵ (LIIT-2707) spores + crystals mL^?1. For D. flavipennella, the LC₅₀ values of strains varied from 0.40 × 10⁵ (LIIT-2707) to 542 × 10⁵ (LIIT-2109) spores + crystals mL^?1. For the LIIT-0105 strain, which was the most toxic to D. saccharalis, the genes cry1Aa, cry1Ab, cry1Ac, cry1B, cry1C, cry1D, cry1F, cry1I, cry2Aa, cry2Ab, cry8, and cry9C were detected, whereas for the strain LIIT-2707, which was the most toxic to D. flavipennella, detected genes were cry1Aa, cry1Ab, cry1Ac, cry1B, cry1D, cry1F, cry1I, cry2Aa, cry2Ab, and cry9. The toxicity data and toxin gene content in these strains of Bt suggest a great variability of activity with potential to be used in the development of novel biopesticides or as source of resistance genes that can be expressed in plants to control pests.     

Karyotypic study of five Lutjanid species using conventional and Ag-NORs banding techniques

The first cytogenetic comparisons of five snapper species from Thailand were presented here. Renal cell samples were taken from blacktail snapper (Lutjanus fulvus), five lined snapper (L. quinquelineatus), dory snapper (L. fulviflamma), brownstripe red snapper (L. vitta), and mangrove red snapper (L. argentimaculatus). The mitotic chromosome preparation was prepared directly from kidney cells. Conventional staining and Ag-NOR banding techniques were applied to stain the chromosomes. The results exhibited that all five snapper species have the diploid chromosome numbers of 2n = 48 and the fundamental numbers (NF) of 48. The presences of large, medium, and small telocentric chromosomes were 22-24-2, 24-20-4, 36-10-2, 28-16-4 and 36-10-2, respectively. The Ag- NORs banding technique provides the pair of nucleolar organizer regions (NORs) at subcentromeric region of the long arm of the respective telocentric chromosome pairs 9, 1, 3, 4 and 9. Their karyotype formulas is as follows: L. fulvus (2n = 48): L ₂₂ ^t + M ₂₄ ^t + S ₂ ^t , L. quinquelineatus (2n = 48): L ₂₄ ^t + M ₂₀ ^t + S ₄ ^t , L. fulviflamma (2n = 48): Lt36 + Mt10 + St2, L. vitta (2n = 48): L ₂₈ ^t + M ₁₆ ^t + S ₄ ^t , and L. argentimaculatus (2n = 48): L ₃₆ ^t + M ₁₀ ^t + S ₂ ^t .     

Protective Effects of <Emphasis Type="Italic">Mekabu</Emphasis> Aqueous Solution Fermented by <Emphasis Type="Italic">Lactobacillus plantarum</Emphasis> Sanriku-SU7 on Human Enterocyte-Like HT-29-luc Cells and DSS-Induced Murine IBD Model

Most wakame Undaria pinnatifida, a brown algae, products are made from the frond portion. In this study, the polysaccharide content and antioxidant property of aqueous extract solutions (AESs) of the four parts (frond: wakame, stem of the frond: kuki-wakame, sporophyll: mekabu, and kuki-mekabu) of wakame were investigated. Polysaccharide content was high in both the wakame and mekabu. Superoxide anion (O₂ ^?) radical-scavenging capacities were high in the mekabu. These AESs could be fermented by Lactobacillus plantarum Sanriku-SU7. The O₂ ^? radical-scavenging activity of the kuki-wakame, mekabu, and kuki-mekabu were increased by the fermentation. Fermented mekabu clearly showed a protective effect on human enterocyte-like HT-29-luc cells and in a mouse model of dextran sodium sulphate-induced inflammatory bowel disease (IBD). These results suggest that the mekabu fermented by L. plantarum Sanriku-SU7 has anti-IBD effect related to O₂ ^? radical-scavenging.     

Microorganisms of low-temperature heavy oil reservoirs (Russia) and their possible application for enhanced oil recovery

Physicochemical and microbiological characteristics of formation waters low-temperature heavy oil reservoirs (Russia) were investigated. The Chernoozerskoe, Yuzhno-Suncheleevskoe, and Severo-Bogemskoe oilfields, which were exploited without water-flooding, were shown to harbor scant microbial communities, while microbial numbers in the water-flooded strata of the Vostochno-Anzirskoe and Cheremukhovskoe oilfields was as high as 10⁶ cells/mL. The rates of sulfate reduction and methanogenesis were low, not exceeding 1982 ng S^2–/(L day) and 9045 nL СН₄/(L day), respectively, in the samples from water-flooded strata. High-throughput sequencing of microbial 16S rRNA gene fragments in the community of injection water revealed the sequences of the Proteobacteria (74.7%), including Betaproteobacteria (40.2%), Alphaproteobacteria (20.7%), Gammaproteobacteria (10.1%), Deltaproteobacteria (2.0%), and Epsilonproteobacteria (1.6%), as well as Firmicutes (7.9%), Bacteroidetes (4.1%), and Archaea (0.2%). DGGE analysis of microbial mcrA genes in the community of injection water revealed methanogens of the genera Methanothrix, Methanospirillum, Methanobacterium, Methanoregula, Methanosarcina, and Methanoculleus, as well as unidentified Thermoplasmata. Pure cultures of bacteria of the genera Rhodococcus, Pseudomonas, Gordonia, Cellulomonas, etc., capable of biosurfactant production when grown on heavy oil, were isolated. Enrichment cultures of fermentative bacteria producing significant amounts of volatile organic acids (acetic, propionic, and butyric) from sacchariferous substrates were obtained. These acids dissolve the carbonates of oil-bearing rock efficiently. Selection of the efficient microbial technology for enhanced recovery of heavy oil from terrigenous and carbonate strata requires model experiments with microbial isolates and the cores of oil-bearing rocks.     

Polymorphism of the genes for antioxidant defense enzymes and their association with the development of chronic obstructive pulmonary disease in the population of Bashkortostan

In this study, frequencies of the polymorphic variants of the genes encoding antioxidant enzymes, GSTM1, GSTT1, GSTP1, CAT, GPX1, NQO1, SOD1, and SOD3 were examined in three ethnic groups of healthy subjects from the Republic of Bashkortostan (Russians, Tatars, and Bashkirs). An association of these markers with the development of chronic obstructive pulmonary disease (COPD) was tested. Interethnic differences relative to the distribution of the polymorphic variants of the GSTP1 locus Ile105Val and the NQO1 locus 609C/T were revealed. Relative to the genotype distribution at the Ile105Val locus of the GSTP1 gene, ethnic group of Bashkirs was found to be statistically significantly different from Tatars (χ² = 8.819; d.f. = 2; P = 0.012). Relative to the genotype frequency distribution pattern at the NQO1 locus 609C/T, the group of Bashkirs differed from Russians (χ² = 8.913; d.f. = 2; P = 0.012). An association of genotype Val/Val of the GSTP1 Ile105Val locus with the risk of COPD in Russians (χ² = 5.25; P = 0.022; P _cor = 0.044; OR = 4.09), and of the GSTP1 haplotype *D in Tatars, was demonstrated (χ² = 11.575; P = 0.0014; P _cor = 0.0042; OR = 3.178). Genotype TT of the CAT ?262C/T locus marked resistance to the COPD development in Russians (χ² = 6.82; P = 0.0098; P _cor = 0.0196; OR = 0.31; 95%CI, 0.119 to 0.77). The risk for COPD in the ethnic group of Tatars was associated with the CAT haplotype (?262)C/(1167)T (χ² = 6.038; P = 0.0147; P _cor = 0.044; OR = 1.71). Analysis of the NQO1 haplotypes at the 465C/T and 609C/T loci showed that haplotype 465C/609T was associated with COPD in Russians (χ² = 4.571; P = 0.0328; P _cor = 0.01; OR = 1.799). It was demonstrated that Gly allele of the Arg213Gly polymorphic locus of the SOD3 gene marked the risk for COPD in the ethnic group of Tatars (OR = 2.23; 95%CI, 1.22 to 4.1). Thus, GSTP1, CAT, NQO1, and SOD3 polymorphisms play an important role in the development of COPD among the population of Bashkortostan.     

The effect of genetic environment on locus-specific instability of the <Emphasis Type="Italic">yellow</Emphasis> gene in the Uman’ population of <Emphasis Type="Italic">Drosophila melanogaster</Emphasis>

The effects of genotype of the laboratory strains, C(1)DX, ywf/Y, 23.5 MRF/CyL ⁴, and C(1)DX,yf; π₂, on locus-specific instability in the yellow gene of the strains y ^2-217, y ^2-715, and y ^2-700 from Uman’ population of Drosophila melanogaster was studied. Crosses of the males from Uman’-derived lines with the C(1)DX,ywf/Y females yielded a cascade of derivatives, mostly consisting of y ⁺ and y ² alleles, while their crosses with the 23.5 MRF/CyL ⁴ and C(1)DX,yf; π₂ females mostly resulted in the appearance of y ⁺ and y ¹ derivatives. The genomes of laboratory strains used in the study contained the full-sized hobo elements, which could differ from one another relative to the structure of variable region and affinity to different DNA sequences.