Reproductive biology and management of two commercially important groupers in the SW Atlantic

The reproductive biology of Epinephelus morio (red grouper) and Mycteroperca bonaci (black grouper) were evaluated based on 533 specimens collected from artisanal fisheries landings in the Abrolhos Bank, Brazil, between May 2005 and September 2012. Sex ratio for the black grouper was 1:14 (n = 155 females and 11 males; 26.1–147 cm TL) and 1:10 for the red grouper (n = 334 females and 33 males; 15.0–96.0 cm TL). For both species, highest values of the gonadosomatic index (GSI) for females were recorded between July and October, indicating spawning during the austral winter. The length at first maturity (L₅₀) for females was estimated at 62.0 and 47.0 cm TL for the black and red grouper, respectively. Batch fecundity based on TL and TW ranged from 2 to 15.4^?10⁶ and 1.5 to 13.7^?10⁶ for the black and red grouper, respectively. Interviews with experienced fishers revealed that spawning seasons of both groupers are largely unrecognized. Results demonstrate a positive relationship between GSI peaks, lower temperatures and stronger winds. The information provided herein may help decision-making regarding fisheries management and conservation for E. morio and M. bonaci at various levels of governance in the Abrolhos Bank, the region with the largest and richest coralline reefs in the South Atlantic.     

<Emphasis Type="Italic">Limnobacter humi</Emphasis> sp. nov., a thiosulfate-oxidizing,heterotrophic bacterium isolated from humus soil,and emended description of the genus <Emphasis Type="Italic">Limnobacter</Emphasis> Spring <Emphasis Type="Italic">et al.</Emphasis> 2001

Three Gram-negative, strictly aerobic, chemolithoheterotrophic bacterial strains, designated UCM-30, UCM-33, and UCM-39^T, were isolated in South Korea. Based on their 16S rRNA gene sequences, the three isolated strains were found to be similar to Limnobacter thiooxidans CS-K2^T (97.41–97.68%), Limnobacter litoralis KP1-19^T (95.55–95.76%), and various genera belonging to the class Betaproteobacteria (90.34–93.34%). DNA-DNA hybridization showed 79.3–83.9% similarity between the genomic DNA of UCM-39^T, UCM-30, and UCM-33, while the sequence similarity between UCM-39^T and L. thiooxidans KACC 13837T or L. litoralis LMG 24869T was 23.7% and 18.6%, respectively. The DNA G+C content of UCM 39T was 59.7 mol%, the major ubiquinone was Q-8, and the optimal oxidation rate was observed at 10 mM thiosulfate. The major fatty acids (≥ 10%) were summed features 3 (C_16:1 ω7c and/or C_16:1 ω6c) and 8 (C_18:1 ω7c and/or C_18:1 ω6c), and C_16:0. The major polar lipids (diphosphatidylglycerol, phosphatidylethanolamine, and phosphatidylglycerol) were found in all members of genus Limnobacter. Based on phenotypic, physiological, and phylogenetic analyses, the UCM-39T strain was found to be significantly distinct to represent a novel species affiliated to the genus Limnobacter. We propose to name it Limnobacter humi sp. nov. with the type strain UCM-39^T (=KACC 18574^T =NBRC 111650^T).     

Age validation and seasonal growth patterns of a subtropical marsh fish: The Gulf Killifish, <Emphasis Type="Italic">Fundulus grandis</Emphasis>

Fundulus grandis (Baird and Girard), the Gulf Killifish, is an abundant species throughout the marshes of the northern Gulf of Mexico. Its wide distribution and high site fidelity makes it an ideal indicator species for brackish and salt marshes, which experience a variety of anthropogenic disturbances. Despite the ecological, commercial, and scientific importance of F. grandis, age determination methods have not been validated and little is known of its growth pattern. By combining a tag-recapture study with a chemical marker to stain otoliths, we validated an ageing method for F. grandis adults (49–128 mm TL) using whole sagittal otoliths and determined growth rates of recaptured individuals in winter (n = 58) and summer (n = 36) in Louisiana. Mean somatic growth in length was significantly greater during the winter (0.085 mm d^?1) than summer (0.054 mm d^?1). In contrast, mean otolith growth was significantly greater in summer (1.37 μm d^?1) than winter (0.826 μm d^?1). The uncoupling of somatic and otolith growth may be primarily attributed to warm summer temperatures, which led to enhanced otolith growth while simultaneously reducing somatic growth. Fundulus grandis was aged to a maximum of 2.25 years. The parameters of the von Bertalanffy growth model were estimated as: L _∞  = 87.27 mm, k = 2.43 year^?1, and t ₀ = ?0.022. These findings reveal essential age and growth information for F. grandis and provide a benchmark to evaluate responses to environmental disturbances.     

Association of polymorphic markers of chemokine genes,their receptors,and <Emphasis Type="Italic">CD14</Emphasis> gene with coronary atherosclerosis

Atherosclerosis represents an inflammatory response to the disturbance of the endothelial layer in the arterial bloodstream. In the present study, an analysis of associations of polymorphic markers for the genes controlling synthesis of proteins involved in atherosclerosis pathogenesis in coronary atherosclerosis (CA) patients (217 subjects) and in a control group (250 subjects) was conducted. The following genes were examined: rs991804 (CCL2 gene), rs1126579 (CXCR2 gene), rs4074 (CXCL1 gene), rs4073 (CXCL8 gene), rs333 (CCR5 gene), rs2471859 (CXCR4 gene), rs1801157 (CXCL12 gene), and rs2569190 (CD14 gene). Using the Monte Carlo and Markov chain (APSampler) method, allele/genotype combinations associated with both low and high CA risk were revealed. The most important findings included the following: CXCR4*T/T + CCL2*C + CCR5*I/I (P_perm = 1 × 10^–6, OR = 0.44, 95% CI 0.3–0.63), CXCR2*C + CD14*C + CXCL12*G + CCL2*C + CCR5*D (P_perm = 4 × 10^–6, OR = 5.78, 95% CI 2.34–14.28), CD14*C + CCL2*C/C + CCR5*D (P_perm = 6.3 × 10^–6, OR = 5.81, 95% CI 2.17–15.56), CXCL8*A + CXCR2*C + CD14*T + CXCR4*C (P_perm = 0.01, OR = 3.21, 95% CI 1.63–6.31).     

<Emphasis Type="Italic">Nibribacter flagellatus</Emphasis> sp. nov., isolated from rhizosphere of <Emphasis Type="Italic">Hibiscus syriacus</Emphasis> and emended description of the genus <Emphasis Type="Italic">Nibribacter</Emphasis>

A Gram-stain negative, aerobic, motile by flagella, rod-shaped strain (THG-T16^T) was isolated from rhizosphere of Hibiscus syriacus. Growth occurred at 10–40 °C (optimum 28–30 °C), at pH 6.0–8.0 (optimum 7.0) and at 0–1.0% NaCl (optimum 0%). Based on 16S rRNA gene sequence analysis, the near phylogenetic neighbours of strain THG-T16^T were identified as Nibribacter koreensis KACC 16450^T (98.6%), Rufibacter roseus KCTC 42217^T (94.7%), Rufibacter immobilis CCTCC AB 2013351^T (94.5%) and Rufibacter tibetensis CCTCC AB 208084^T (94.4%). The DNA G+C content of strain THG-T16^T was determined to be 46.7 mol%. DNA–DNA hybridization values between strain THG-T16^T and N. koreensis KACC 16450^T, R. roseus KCTC 42217^T, R. immobilis CCTCC AB 2013351^T, R.tibetensis CCTCC AB 208084^T were 33.5?±?0.5% (31.7?±?0.7% reciprocal analysis), 28.1?±?0.2% (25.2?±?0.2%), 17.1?±?0.9% (10.2?±?0.6%) and 8.1?±?0.3% (5.2?±?0.1%). The polar lipids were identified as phosphatidylethanolamine, two unidentified aminophospholipids, an unidentified aminolipid and three unidentified lipids. The quinone was identified as MK-7 and the polyamine as sym-homospermidine. The major fatty acids were identified as C_16:1 ω5c, C_17:1 ω6c, iso-C_15:0, summed feature 3 (C_16:1 ω7c and/or C_16:1 ω6c) and summed feature 4 (iso-C_17:1 I and/or anteiso-C_17:1 B). On the basis of the phylogenetic analysis, chemotaxonomic data, physiological characteristics, and DNA–DNA hybridization data, strain THG-T16^T represents a novel species of the genus Nibribacter, for which the name Nibribacter flagellatus sp. nov. is proposed. The type strain is THG-T16^T(=?KACC 19188^T?=?CCTCC AB 2016246^T).     

Age,growth and reproduction of the Iranian goby, <Emphasis Type="Italic">Ponticola iranicus</Emphasis> (Perciformes: Gobiidae) from the southern Caspian Sea basin

To estimate reproductive biology of Ponticola iranicus Vasil’eva et al., 2015, in Sefidroud River in the southern Caspian Sea basin age, sex ratio, fecundity, oocytes diameter, gonadosomatic, modified gonadosomatic and dobriyal indices were measured. Regression analyses were used to find relations between fecundity and fish size (length and weight), gonad weight, and age. Mature females and males were longer than 46 and 49 mm in total length, +1 in age. The Von Bertalanffy growth models were L _∞ = 23.00 cm (TL), K = 0.21, t ₀ =–0.25 for all specimens. Sex ratio was 1: 1.32 in favor of males. The average egg diameter was 0.96 mm. The spawning period extended from late February to late April. The averages of absolute and relative fecundity were calculated as 536.9 and 81.3, respectively. The absolute fecundity was significantly related to the body length and weight, as well as gonad weight.     

<Emphasis Type="Italic">Gallaecimonas mangrovi</Emphasis> sp. nov., a novel bacterium isolated from mangrove sediment

A Gram-stain negative, rod-shaped, non-motile, strictly aerobic bacterium HK-28^T was isolated from a mangrove sediment sample in Haikou city, Hainan Province, China. Strain HK-28^T was able to grow at 10–45 °C (optimum 25–30 °C), pH 5.0–8.5 (optimum 6.0–7.0) and 0.5–12.0% (w/v) NaCl (optimum 1.0–3.0%, w/v). The major cellular fatty acids were C_16:0, Summed Feature 8 (C_18:1 ω7c and/or C_18:1 ω6c), Summed Feature 3 (C_16:1 ω7c and/or C_16:1 ω6c), C_17:0, C_12:0 3-OH and C_17:1ω8c. Ubiquinone-8 (Q-8) was the predominant respiratory quinone. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, two unidentified aminophospholipids, four unidentified phospholipids, two unidentified glycolipid, an unidentified glycophospholipid, an unidentified aminolipid and an unidentified lipid. The DNA G+C content was 50.2 mol%. Accoroding to 16S rRNA gene sequence similarities, strain HK-28^T shared 97.1 and 96.7% sequence similarities to the validly named species Gallaecimonas xiamenensis MCCC 1A01354^T and Gallaecimonas pentaromativorans MCCC 1A06435^T, respectively, and shared lower sequence similarities (<?92.0%) to all other genera. Phylogenetic analysis showed strain HK-28^T was clustered with G. pentaromativorans MCCC 1A06435^T and G. xiamenensis MCCC 1A01354^T. Strain HK-28^T showed low DNA–DNA relatedness with G. xiamenensis MCCC 1A01354^T (28.3?±?1.5%) and G. pentaromativorans MCCC 1A06435^T (25.2?±?2.4%). On the basis of phenotypic, chemotaxonomic and genotypic characteristics, strain HK-28^T is considered to represent a novel species in the genus Gallaecimonas, for which the name Gallaecimonas mangrovi sp. nov. is proposed. The type strain is HK-28^T (=?KCTC 62177^T?=?MCCC 1K03441).     

<Emphasis Type="Italic">Flavobacterium zaozhuangense</Emphasis> sp. nov., a new member of the family <Emphasis Type="Italic">Flavobacteriaceae</Emphasis>, isolated from metolachlor-contaminated soil

Strain ZZ-8^T, a Gram-negative, aerobic, non-spore-forming, non-motile, yellow-pigmented, rod-shaped bacterium, was isolated from metolachlor-contaminated soil in China. The taxonomic position was investigated using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain ZZ-8^T is a member of the genus Flavobacterium and shows high sequence similarity to Flavobacterium humicola UCM-46^T (97.2%) and Flavobacterium pedocola UCM-R36^T (97.1%), and lower (<?97%) sequence similarity to other known Flavobacterium species. Chemotaxonomic analysis revealed that strain ZZ-8^T possessed MK-6 as the major respiratory quinone; and iso-C_15:0 (28.5%), summed feature 9 (iso-C_17:1 w9c/C_16:0 10-methyl, 22.9%), iso-C_17:0 3-OH (17.0%), iso-C_15:0 3-OH (8.9%), iso-C_15:1 G (8.6%) and summed feature 3 (C_16:1 w7c/C_16:1 w6c, 5.7%) as the predominant fatty acids. The polar lipids of strain ZZ-8^T were determined to be lipids, a glycolipid, aminolipids and phosphatidylethanolamine. Strain ZZ-8^T showed low DNA–DNA relatedness with F. pedocola UCM-R36^T (43.23?±?4.1%) and F. humicola UCM-46^T (29.17?±?3.8%). The DNA G+C content was 43.3 mol%. Based on the phylogenetic and phenotypic characteristics, chemotaxonomic data and DNA–DNA hybridization, strain ZZ-8^T is considered a novel species of the genus Flavobacterium, for which the name Flavobacterium zaozhuangense sp. nov. (type strain ZZ-8^T?=?KCTC 62315 ^T?=?CCTCC AB 2017243^T) is proposed.     

Inheritance of Traits Controlled by Odd Chromosomes Using Data on Transmission of Monosomic Addition S<Superscript>t</Superscript> Chromosome of the <Emphasis Type="Italic">Elymus Sibiricus</Emphasis> Genome

On the basis of the winter bread wheat cultivar Obryi, two independent disomic addition lines BC₁₂F_∞ with the chromosome of the E. sibiricus S^t genome are created. A practical algorithm for determining the probabilities of transmission of the odd chromosome separately through male and female gametes in selfpollination of hemizygous hybrids from the equation p²–(1 + f₁–f₄) × p + f₁ = 0 is proposed, where p is the probability of the formation of viable gametes with the considered chromosome and f₁ and f₄ are the empirical frequencies of the corresponding homozygotes with and without the trait. The probability of transmission of an alien univalent chromosome through pollen (p_♂) is associated with the frequency of its transmission through the egg cell (p_♀) in backcrosses and in self-pollination (1–f₄) by the equation p_♂ = 1–f₄/(1–p_♀). The calculated empirically dependent estimates of the probabilities of transmission of the added chromosome through the egg cell p_♀ = 18.7% and through pollen p_♂ = 4.3% correspond to the empirical frequencies obtained for backcrosses. The coefficients of the gamete selection V_♀ = 0.748 and V_♂ = 0.172 are calculated, and the expected segregation for the alien trait controlled by a dominant gene located in the added chromosome is determined—with the trait: without the trait is 0.222: 0.778 in F₂; 0.187: 0.813 in equational and 0.043: 0.957 in certational backcrosses.     

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.     

Parasitism Rate of <Emphasis Type="Italic">Habrobracon hebetor</Emphasis> to <Emphasis Type="Italic">Ephestia kuehniella</Emphasis> Larvae: Residual Effect of Deltamethrin,Fenvalerate and Azadirachtin

Sublethal concentrations of chemical insecticides may cause changes in some behavioral characteristics of natural enemies such as functional responses. The residual effect of three synthetic insecticides including deltamethrin, fenvalerate and azadirachtin were studied on functional response of Habrobracon hebetor Say to Ephestia kuehniella Zeller larvae. Seven host densities (2, 4, 8, 16, 32, 64 and 96) were used during a 24 h period. The resulting data were appropriately fit to Type II functional response models in all treatments: (1) control (0.0916 h^?1; and T _h  = 0.2011 h); (2) deltamethrin (a = 0.0839 h^?1; and T _h  = 0.3560 h); (3) fenvalerate (a = 0.0808 h^?1 and T _h  = 0.3623 h); and (4) azadirachtin (a = 0.0900 h^?1 and T _h  = 0.2042 h). Maximum theoretical parasitism rate (T/T _h ) was 119.34 estimated for control wasps. There was no significant difference between the values of attack rates (a and a + D _a ) in all treatments while the handling time was statistically affected in female wasps treated with fenvalerate. Our findings will be useful in safe application of these insecticides in pest management programmes.     

Short-term effects of crop rotation,residue management,and soil water on carbon mineralization in a tropical cropping system

The purpose of this study was to investigate the short-term effects of maize (Zea mays)-fallow rotation, residue management, and soil water on carbon mineralization in a tropical cropping system in Ghana. After 15 months of the trial, maize–legume rotation treatments had significantly (P?C ₀ (μg CO₂–C g^?1) than maize–elephant grass (Pennisetum purpureum) rotations. The C ₀ for maize–grass rotation treatments was significantly related to the biomass input (r?=?0.95; P?=?0.05), but that for the maize–legume rotation was not. The soil carbon mineralization rate constant, k (per day), was also significantly related to the rotation treatments (P?k values for maize–grass and maize–legume rotation treatments were 0.025 and 0.036 day^?1 respectively. The initial carbon mineralization rate, m ₀ (μg CO₂–C g^?1 day ^?1), was significantly (P?θ. The m ₀ ranged from 3.88 to 18.67 and from 2.30 to 15.35 μg CO₂–C g^?1 day^?1 for maize–legume and maize–grass rotation treatments, respectively, when the soil water varied from 28% to 95% field capacity (FC). A simple soil water content (θ)-based factor, f _w, formulated as: \(f_{\text{w}} = \left[ {\frac{{\theta - \theta _{\text{d}} }}{{\theta _{{\text{FC}}} - \theta _{\text{d}} }}} \right]\), where θ _d and θ _FC were the air-dry and field capacity soil water content, respectively, adequately described the variation of the m ₀ with respect to soil water (R ²?=?0.91; RMSE?=?1.6). Such a simple relationship could be useful for SOC modeling under variable soil water conditions.     

Aspects of the reproductive biology of the data-deficient <Emphasis Type="Italic">Mustelus minicanis</Emphasis> and <Emphasis Type="Italic">M. norrisi</Emphasis> (Chondrichthyes: Triakidae) in the southern Caribbean Sea

Reproduction and maturation in the economically important, but data-deficient, Mustelus minicanis and M. norrisi were analysed using catches of populations exploited by a gillnet fishery during two years in the southern Caribbean Sea. In total, 691 female (mean ± SD total length–TL of 55.3 ± 5.8 cm) and 503 male (50.4 ± 4.9 cm TL) M. minicanis were assessed, with ~95% of all specimens deemed mature. Almost 25% of females were gravid (occurring between January and October) and with variable temporal development of up to six embryos (3.3 ± 1.2), implying protracted temporal parturition. Parity in the sex ratio of embryos, but not in landed catches, suggested sexual segregation across the fished area. The 50% sizes at maturity (M ₅₀) (± SE) were similarly estimated at 45.11 (± 0.39) and 45.48 (± 0.42) cm TL for females and males, respectively. Relatively fewer (235) M. norrisi were landed, with samples comprising 150 females (82.6 ± 18.1 cm TL) and 85 males (75.5 ± 17.7 cm TL). More than 30% of both sexes were immature. Ten percent of females were gravid (up to 11 embryos) and present in catches between October and February, coinciding with the northern hemisphere autumn/winter. Female and male M ₅₀s were 76.65 (± 1.16) and 69.63 (± 1.92) cm TL, respectively. The results imply variable inter-specific reproductive plasticity and the need for further life-history studies. Increasing gillnet selectivity might represent a simple precautionary management option for concurrently regulating catches of the smaller-bodied M. minicanis during peak abundances of gravid females and similar-sized juvenile M. norrisi.     

An NADPH-dependent <Emphasis Type="Italic">Lactobacillus composti</Emphasis> short-chain dehydrogenase/reductase: characterization and application to (<Emphasis Type="Italic">R</Emphasis>)-1-phenylethanol synthesis

A new anti-Prelog short-chain dehydrogenase/reductase (SDR) encoding gene lcsdr was cloned from Lactobacillus composti DSM 18527, and heterologously expressed in Escherichia coli. LcSDR is nicotinamide adenine dinucleotide phosphate (NADPH)-dependent and has a molecular weight of approximately 30 kDa. The optimal pH and temperature were 6.5 and 30?°C, respectively. The maximal reaction rate V_max was 133.9 U mg^?1; the Michaelis–Menten constant K _m of LcSDR were 0.345 mM for acetophenone (1a), and 0.085 mM for NADPH. Through introducing an EsGDH-catalyzed NADPH regeneration system, a biocatalytic process for (R)-1-phenylethanol ((R)-1b) was developed with outstanding time–space yield. Under the optimized conditions, 50 g l^?1 1a was converted to (R)-1b in 2 h with a yield of 93.8%, enantiomeric excess of product (e.e._p) above 99% and space–time yield of 562.8 g l^?1 d^?1.     

Influence of latitudinal variation in environmental gradients and population structure on the demography of a widespread pelagic fish, <Emphasis Type="Italic">Arripis trutta</Emphasis> (Forster, 1801)

Knowledge of the influence of both spatial and temporal environmental gradients on life history traits and population demographics is a critical requirement in the management of exploited fish populations. This study examined variation in the demographics of Arripis trutta, an economically-important pelagic fish species with a broad latitudinal distribution in the waters of coastal south-eastern (SE) Australia, a region dominated by the influence of the East Australian Current (EAC). A validated ageing protocol was first developed using sectioned sagittal otoliths, which in turn permitted examination of latitudinal variation in A. trutta growth, size compositions and age compositions. The von Bertalanffy growth function parameters for A. trutta in SE Australia were estimated to be L _∞?=?63.20?±?0.37 cm fork length (FL), k?=?0.26?±?0.01 yr^?1 and t _o?=??0.14?±?0.03 yr, with a maximum estimated age of 12.7 years. Growth was shown to be faster with decreasing latitude likely due to a simple relationship with the latitudinal gradient in water temperature; fastest growth occurring in northern NSW and slowest growth occurring in Tasmania. Latitudinal patterns in growth were remarkably similar to those previously reported for this species, despite age being estimated using scale readings some 40 years ago. This consistency in latitudinal growth patterns of a temperate fish can be attributed to the life history-related movements undertaken by A. trutta in this region. This temporally-consistent movement pattern is supported by the spatial gradient in the size and age composition of A. trutta sampled from different latitudes in both the current and historical research, whereby numbers of large and old fish increase progressively from Tasmania to northern NSW. These results highlight the need to consider the potential for spatial size- or age-structuring in the development of sampling designs and interpretation of results for any study examining spatial or temporal variation in demographic parameters of exploited fish populations.     

Kinetic Analyses of the Substrate Inhibition of <Emphasis Type="Italic">Paramecium</Emphasis> Arginine Kinase

Paramecium tetraurelia expresses four types of arginine kinase (AK1–AK4). In a previous study, we showed that AK3 is characterized by typical arginine substrate inhibition, where enzymatic activity markedly decreases near a concentration of 1 mM of arginine substrate. This is in sharp contrast to the three other AK types, which obey the Michaelis–Menten reaction curve. Since cellular arginine concentration in another ciliate Tetrahymena is estimated to be 3–15 mM in vivo, Paramecium AK3 likely functions in conditions that are strongly affected by substrate inhibition. The purpose of this work is to find some novel aspect on the kinetic mechanism of the substrate inhibition of Paramecium AK3 enzyme. Substrate inhibition kinetics for AK3 were analyzed using three models and their validity were evaluated with three static parameters (R², AICc, and Sy.x). The most accurate model indicated that not only ES but also the SES complex reacts to form products, the latter being the complex with two substrates in the active center. The maximum reaction rate for the SES complex, V_max^SES?=?30.4 µmol Pi/min/mg protein, was one-eighth of the ES complex, V_max^ES?=?241.7. The dissociation constant for the SES complex (K_i^SES: 0.34 mM) was two times smaller than that of the ES complex (K_s^ES: 0.61 mM), suggesting that after the primary binding of the arginine substrate (ES complex formation), the binding of a second arginine to the secondarily induced inhibitory site is accelerated to form an SES complex with a lower V_max^SES. The same kinetics were used for the S79A, S80A, and V81A mutants. The results indicate that the S79 residue is significantly involved in the process of binding the second arginine substrate. Herein, the K_i^SES value was ten times (3.62 mM) the value for the wild-type (0.34 mM), weakening substrate inhibition. In contrast, V_max^ES and V_max^SES values for the mutants decreased by one-third, except for the V_max^SES of the S79A mutant, which had a value that was comparable with the value for the wild-type.     

Carbon Inputs from <Emphasis Type="Italic">Miscanthus</Emphasis> Displace Older Soil Organic Carbon Without Inducing Priming

The carbon (C) dynamics of a bioenergy system are key to correctly defining its viability as a sustainable alternative to conventional fossil fuel energy sources. Recent studies have quantified the greenhouse gas mitigation potential of these bioenergy crops, often concluding that C sequestration in soils plays a primary role in offsetting emissions through energy generation. Miscanthus is a particularly promising bioenergy crop and research has shown that soil C stocks can increase by more than 2 t C ha^?1 yr^?1. In this study, we use a stable isotope (¹³C) technique to trace the inputs and outputs from soils below a commercial Miscanthus plantation in Lincolnshire, UK, over the first 7 years of growth after conversion from a conventional arable crop. Results suggest that an unchanging total topsoil (0–30 cm) C stock is caused by Miscanthus additions displacing older soil organic matter. Further, using a comparison between bare soil plots (no new Miscanthus inputs) and undisturbed Miscanthus controls, soil respiration was seen to be unaffected through priming by fresh inputs or rhizosphere. The temperature sensitivity of old soil C was also seen to be very similar with and without the presence of live root biomass. Total soil respiration from control plots was dominated by Miscanthus-derived emissions with autotrophic respiration alone accounting for ～50 % of CO₂. Although total soil C stocks did not change significantly over time, the Miscanthus-derived soil C accumulated at a rate of 860 kg C ha^?1 yr^?1 over the top 30 cm. Ultimately, the results from this study indicate that soil C stocks below Miscanthus plantations do not necessarily increase during the first 7 years.     

<Emphasis Type="Italic">Hoeflea prorocentri</Emphasis> sp. nov., isolated from a culture of the marine dinoflagellate <Emphasis Type="Italic">Prorocentrum mexicanum</Emphasis> PM01

A Gram-stain negative, aerobic, rod-shaped, non-motile, yellow-pigmented and non-spore-forming bacterial strain, designated PM5-8^T, was isolated from a culture of a marine toxigenic dinoflagellate Prorocentrum mexicanum PM01. Strain PM5-8^T grew at 15–35 °C (optimum, 25–30 °C) and pH 6–11 (optimum, 7.5–8). Cells required at least 1.5% (w/v) NaCl for growth, and can tolerate up to 7.0% with the optimum of 4%. Phylogenetic analysis based on 16S rRNA gene sequence revealed that the strain PM5-8^T is closely related to members of the genus Hoeflea, with high sequence similarities with Hoeflea halophila JG120-1^T (97.06%) and Hoeflea alexandrii AM1V30^T (97.01%). DNA–DNA hybridization values between the isolate and other type strains of recognized species of the genus Hoeflea were between 11.8 and 25.2%, which is far below the value of 70% threshold for species delineation. The DNA G?+?C content was 50.3 mol%. The predominant cellular fatty acids of the strain were identified as summed feature 8 (C_16:1 ω7c and/or C_16:1 ω6c; 51.5%), C_18:1 ω7c 11-methyl (20.7%), C_16:0 (17.2%) and C_18:0 (5.7%). The major respiratory quinone was Q-10. Polar lipids profiles contained phosphatidylcholine, phosphatidylglycerol, sulfoquinovosyl diacylglycerol, phosphatidylmono- methylethanolamine, phosphatidylethanolamine and four unidentified lipids. On the basis of the polyphasic taxonomic data presented, strain PM5-8^T (=?CCTCC AB 2016294^T?=?KCTC 62490^T) represents a novel species of the genus Hoeflea, for which the name Hoeflea prorocentri sp. nov. is proposed.     

<Emphasis Type="Italic">Corynebacterium defluvii</Emphasis> sp. nov., isolated from Sewage

A Gram-positive, aerobic, non-motile, rod-shapeds, catalase-positive, and oxidase-negative strain, designated Y49^T, was isolated from sewage collected from Jilin Agricultural University, China. It grew at 20–40°C (optimum at 30°C), at pH 6.0–8.0 (optimum at 7.0) and at 0–1.0% sodium chloride (optimum at 0%). The major isoprenoid quinone was menaquinone-8 (MK-8) and the polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylmethylethanolamine, four unidentified lipids, and two unidentified aminolipids. The peptidoglycan was meso-diaminopimelic acid. The cell-wall sugars were galactose, arabinose, and glucose. The fatty acids were C_9:0, C_16:0, C_16:1 ω9c, C_17:1 ω9c, C_18:3 ω6c (6,9,12), C_18:1 ω9c, and C_18:0. The DNA G+C content was 51.4 mol%. Based on the 16S rRNA gene sequence analysis, the nearest phylogenetic neighbors of strain Y49^T were Corynebacterium efficiens DSM 44549^T (97.5%), Corynebacterium callunae DSM 20147^T (97.2%), Corynebacterium deserti GIMN 1.010^T (96.8%), Corynebacterium glutamicum ATCC 13032^T (96.4%), and other species belonging to this genus (92.3–95.4%). The DNA-DNA relatedness value between strain Y49^T and C. efficiens DSM 44549^T, C. callunae DSM 20147^T, C. deserti GIMN1.010^T, and C. glutamicum ATCC 13032^T was 25.5±2.0%, 21.1±1.0%, 16.5±0.5%, and 13.5±0.9%, respectively. Based on the phylogenetic analysis, chemotaxonomic data, physiological characteristics and DNA-DNA hybridization data, strain Y49^T represents a novel species of the genus Corynebacterium, for which the name Corynebacterium defluvii sp nov. is proposed. The type strain is Y49^T (= KCTC 39731^T =CGMCC 1.15506^T).