Sphingomonas gimensis sp. nov., a novel Gram-negative bacterium isolated from abandoned lead–zinc ore mine

A novel bacterial strain designated 9PNM-6^T was isolated from an abandoned lead–zinc ore mine site in Meizhou, Guangdong Province, China. The isolate was found to be Gram-negative, rod-shaped, orange-pigmented, strictly aerobic, oxidase- and catalase-positive. Growth occurred at 0–4 % NaCl (w/v, optimum, 0 %), at pH 6.0–8.0 (optimum, pH 7.0) and at 15–32 °C (optimum, 28–30 °C). Phylogenetic analysis based on 16S rRNA gene sequence similarities showed that strain 9PNM-6^T belongs to the genus Sphingomonas, with the highest sequence similarities with Sphingomonas jejuensis NBRC 107775^T (99.7 %), Sphingomonas koreensis KCTC 2882^T (95.1 %) and Sphingomonas dokdonesis KCTC 12541^T (95.1 %). The chemotaxonomic characteristics of strain 9PNM-6^T were consistent with those of the genus Sphingomonas. The predominant respiratory quinone was identified as ubiquinone Q-10, the major polyamine as sym-homospermidine, and the major cellular fatty acids as C_18:1 ω7c, C_16:0, C_16:1 ω7c and/or C_16:1 ω6c and C_14:0 2-OH. The major polar lipids are sphingoglycolipid, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatideylcholine, an unidentified phospholipid and four unidentified aminolipids. The genomic DNA G+C content of strain 9PNM-6^T was determined to be 69.2 ± 0.6 mol%. Based on comparative analyses of morphological, physiological and chemotaxonomic data, and levels of DNA–DNA relatedness values, strain 9PNM-6^T is considered to represent a novel species of the genus Sphingomonas, for which the name Sphingomonas gimensis sp. nov. (Type strain 9PNM-6^T = GIMCC 1.655^T = CGMCC 1.12671^T = DSM 27569^T) is proposed.     

Effect of Temperature on Development and Reproduction of <Emphasis Type="Italic">Epilachna dodecastigma</Emphasis> (Wied.) (Coleoptera: Coccinellidae)

The effect of five constant temperatures of 21, 24, 27, 30 and 33 °C on adult life span, reproduction, oviposition behavior and larval developmental time of a bitter gourd inhabited coleopteran insect Epilachna dodecastigma (Wied.) (Coccinellidae) was determined in laboratory conditions under 70 ± 5 % relative humidity and a photoperiod of 12 L : 12 D. Larval developmental time of E. dodecastigma decreased as temperature increased from 21 to 33 °C. Life table data revealed that overall mortality was lowest at 27 °C and highest at 21 °C. Females lived longer than males at all temperatures; but longevity decreased with increase in temperature. Pre-oviposition period decreased significantly with increase in temperature up to 27 °C and thereafter increased at a slower rate; whereas oviposition period decreased significantly with increase in temperature. Fecundity and egg viability increased significantly with an increase in temperature up to 27 °C and thereafter decreased at a slower rate. The intrinsic rate of increase (r _m ) was 0.1703, 0.1984, 0.2235, 0.2227 and 0.2181 day^?1 at 21, 24, 27, 30 and 33 °C, respectively. The net reproductive rate and finite rate of increase was highest at 27 °C (R _o  = 112.05; λ = 1.4233) and lowest at 21 °C (R _o  = 51.23; λ = 1.2581).     

Numerical analysis of the influence of nucleus pulposus removal on the biomechanical behavior of a lumbar motion segment

Nucleus replacement was deemed to have therapeutic potential for patients with intervertebral disc herniation. However, whether a patient would benefit from nucleus replacement is technically unclear. This study aimed to investigate the influence of nucleus pulposus (NP) removal on the biomechanical behavior of a lumbar motion segment and to further explore a computational method of biomechanical characteristics of NP removal, which can evaluate the mechanical stability of pulposus replacement. We, respectively, reconstructed three types of models for a mildly herniated disc and three types of models for a severely herniated disc based on a L4–L5 segment finite element model with computed tomography image data from a healthy adult. First, the NP was removed from the herniated disc models, and the biomechanical behavior of NP removal was simulated. Second, the NP cavities were filled with an experimental material (Poisson's ratio = 0.3; elastic modulus = 3 MPa), and the biomechanical behavior of pulposus replacement was simulated. The simulations were carried out under the five loadings of axial compression, flexion, lateral bending, extension, and axial rotation. The changes of the four biomechanical characteristics, i.e. the rotation degree, the maximum stress in the annulus fibrosus (AF), joint facet contact forces, and the maximum disc deformation, were computed for all models. Experimental results showed that the rotation range, the maximum AF stress, and joint facet contact forces increased, and the maximum disc deformation decreased after NP removal, while they changed in the opposite way after the nucleus cavities were filled with the experimental material.     

Halomonas zhaodongensis sp. nov., a slightly halophilic bacterium isolated from saline–alkaline soils in Zhaodong, China

A slightly halophilic bacterium (strain NEAU-ST10-25^T) was isolated from saline–alkaline soils in Zhaodong City, Heilongjiang Province, China. The strain is a Gram-negative, aerobic motile rod. It accumulates poly-β-hydroxyalkanoate and produces exopolysaccharide. It produces beige-yellow colonies. Growth occurs at NaCl concentrations (w/v) of 0–15 % (optimum 3 %), at temperatures of 4–60 °C (optimum 35 °C) and at pH 6–12 (optimum pH 9). Its G+C content is 53.8 mol%. Phylogenetic analyses based on the separate 16S rRNA gene and concatenation of the 16S rRNA, gyrB and rpoD genes indicate that it belongs to the genus Halomonas in the class Gammaproteobacteria. The most phylogenetically related species is Halomonas alkaliphila DSM 16354^T, with which strain NEAU-ST10-25^T showed 16S rRNA, gyrB and rpoD gene sequence similarities of 99.2, 82.3 and 88.2 %, respectively. The results of DNA–DNA hybridization assays showed 60.47 ± 0.69 % DNA relatedness between strain NEAU-ST10-25^T and H. alkaliphila DSM 16354^T, 42.43 ± 0.37 % between strain NEAU-ST10-25^T and Halomonas venusta DSM 4743^T and 30.62 ± 0.43 % between strain NEAU-ST10-25^T and Halomonas hydrothermalis DSM 15725^T. The major fatty acids are C_18:1 ω7c (62.3 %), C_16:0 (17.6 %), C_16:1 ω7c/C_16:1 ω6c (7.7 %), C_14:0 (2.9 %), C_12:0 3-OH (2.8 %), C_10:0 (2.1 %) and C_18:1 ω9c (1.6 %) and the predominant respiratory quinone is ubiquinone 9 (Q-9). The proposed name is Halomonas zhaodongensis, NEAU-ST10-25^T (=CGMCC 1.12286^T = DSM 25869^T) being the type strain.     

Phytoplankton as a monitoring tool in a tropical urban shallow reservoir (Garças Pond): the assemblage index application

This study aimed at evaluating phytoplankton as a monitoring tool for water quality assessment in an urban shallow eutrophic reservoir considering temporal and vertical scales. Garças Reservoir is located in the Parque Estadual das Fontes do Ipiranga Biological Reserve (23°38′08″S and 23°40′18″S; 46°36′48″W and 46°38′00″W) that lies in the southeastern part of the Municipality of São Paulo, southeast Brazil. Samplings were carried out monthly during 8 consecutive years (1997–2004) following the water column vertical profile (5 depths: subsurface, 1, 2, 3 m and ~20 cm from the bottom). Abiotic variables analyzed were: water temperature, electric conductivity, DO, pH, total alkalinity, free CO₂, dissolved inorganic carbon, N series, P series and SiO₄H₄. Biological variables studied were: total density, total biomass and chlorophyll a, which were integrated arithmetically. At the beginning of the 8 year series, Garças Reservoir was an eutrophic ecosystem with 20% of its surface covered by Eichhornia crassipes (phase I: January 1997–March 1998). Water hyacinth reached 70% of pond surface coverage (phase II: April 1998–August 1999), and then it was mechanically removed (phase III: September 1999–December 2004). After this intervention, drastic alteration in the limnological features was detected, leading to the conclusion that removal of the aquatic macrophyte modified nutrient dynamics drastically reduced water transparency and led to photosynthetic productivity and phytoplankton biomass increase, the latter becoming a physical barrier to light penetration. Twenty one functional groups ‘sensu’ Reynolds were identified. Cyanobacteria contribution played the main role during the drastic alterations that occurred after water hyacinth removal. Results of ecological status of reservoir using Q index showed statistical difference among the 3 limnological phases (one way ANOVA; F = 119.4; P = 0.000). Regarding Q index classification, Garças Reservoir limnological phases were characterized as follows: (1) phase I: 0 ≥ Q ≤ 2.9, medium to bad; (2) phase II: 1.4 ≥ Q ≤ 3, tolerable to medium; and (3) phase III: 0 ≥ Q ≤ 1.5, bad to tolerable ecological states.     

Acinetobacter refrigeratorensis sp. nov., Isolated from a Domestic Refrigerator

A Gram-negative bacterial strain, designated WB1^T, was isolated from a domestic refrigerator in Guangzhou, PR China. Cells of strain WB1^T were oxidase-negative, catalase-positive, strictly aerobic, non-spore-forming and non-motile coccobacilli with peritrichous fimbriae-like structures. The strain was able to grow at 10–40 °C with optimum growth at 28–30 °C, pH 6.0–8.0 (optimum, pH 7.0) and 0–6 % NaCl (w/v, optimum, 0.5 %). Phylogenetic analyses based on 16S rRNA gene and rpoB gene sequences revealed that strain WB1^T belonged to the genus Acinetobacter and was most closely related to A. indicus DSM 25388^T (97.2 % 16S rRNA gene sequence similarity) and A. radioresistens NBRC 102413^T (96.8 %). The DNA G + C content of strain WB1^T was 46.74 ± 0.04 mol % and the major fatty acids comprised summed feature 3 (C_16:1 ω7c and/or C_16:1 ω6c), C_18:1 ω9c, C_16:0 and C_12:0. The predominant respiratory quinone was identified as Q-9 and the polar lipids as diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine and an unidentified phospholipid. Phenotypic, phylogenetic and chemotaxonomic data, including low DNA–DNA relatedness with closely related type strains, supported that strain WB1^T represents a distinct novel species in the genus Acinetobacter, for which the name Acinetobacter refrigeratorensis sp. nov. was proposed. The type strain is WB1^T (=GIMCC 1.663^T = CCTCC AB 2014197^T = KCTC 42011^T).     

<Emphasis Type="Italic">Streptomyces caldifontis</Emphasis> sp. nov., isolated from a hot water spring of Tatta Pani,Kotli, Pakistan

A Gram-staining positive, non-motile, rod-shaped, catalase positive and oxidase negative bacterium, designated NCCP-1331^T, was isolated from a hot water spring soil collected from Tatta Pani, Kotli, Azad Jammu and Kashmir, Pakistan. The isolate grew at a temperature range of 18-40 °C (optimum 30 °C), pH 6.0–9.0 (optimum 7.0) and with 0–6 % NaCl (optimum 2 % NaCl (w/v)). The phylogenetic analysis based on 16S rRNA gene sequence revealed that strain NCCP-1331^T belonged to the genus Streptomyces and is closely related to Streptomyces brevispora BK160^T with 97.9 % nucleotide similarity, followed by Streptomyces drosdowiczii NRRL B-24297^T with 97.8 % nucleotide similarity. The DNA–DNA relatedness values of strain NCCP-1331^T with S. brevispora KACC 21093^T and S. drosdowiczii CBMAI 0498^T were 42.7 and 34.7 %, respectively. LL-DAP was detected as diagnostic amino acid along with alanine, glycine, leucine and glutamic acid. The isolate contained MK-9(H₈) as the predominant menaquinone. Major polar lipids detected in NCCP-1331^T were phosphatidylethanolamine, phosphatidylinositol and unidentified phospholipids. Major fatty acids were iso-C_{16: 0}, summed feature 8 (18:1 ω7c/18:1 ω6c), anteiso-C_15:0 and C_16:0. The genomic DNA G + C content was 69.8 mol %. On the basis of phylogenetic, phenotypic and chemotaxonomic analysis, it is concluded that strain NCCP-1331^T represents a novel species of the genus Streptomyces, for which the name Streptomyces caldifontis sp. nov. is proposed. The type strain is NCCP-1331^T (=KCTC 39537^T = CPCC 204147^T).     

Tabrizicola aquatica gen. nov. sp. nov., a novel alphaproteobacterium isolated from Qurugöl Lake nearby Tabriz city, Iran

A novel Gram-negative, aerobic, non-motile and rod-shaped bacterium was isolated from Qurugöl Lake near Tabriz city. The bacterium grew chemoorganolheterotrophically and chemolithoautotrophically. However, photo-organoheterotrophic, photo-lithoautotrophic and fermentative growth could not be demonstrated. The presence of photosynthesis genes pufL and pufM was not shown and photosynthesis pigments were not formed. Strain RCRI19^T grew without NaCl and tolerated up to 3 % NaCl. Growth occurred at pH 6–9 (optimum, pH 7) and 15–55 °C (optimum 40–45 °C). Vitamins were not required for growth. The major fatty acids are C_18:1 ω7C, 11-methyl C_18:1 ω7C, C_18:0 3-OH. The predominant respiratory quinone is ubiquinone Q-10. The G+C content of genomic DNA is 65.9 mol%. Analysis of 16S rRNA sequences showed that strain RCRI19^T has the highest similarities with uncultured environmental sequences followed by members of the genera Rhodobacter (≤95.75 %), Haematobacter (≤95.53 %), Gemmobacter (≤95.17 %) and Falsirhodobacter (94.60 %) in the family Rhodobacteraceae. DNA–DNA relatedness between strain RCRI19^T and the closest phylogenetically related strain, Rhodobacter blasticus LMG 4305^T, was 20 %. Based on its phenotypic and chemotaxonomic characteristics and considering that it does not form photosynthetic pigments and is unable to grow phototrophically, it is concluded that strain RCRI19^T cannot be included into the genus Rhodobacter and any of the other related genera. Therefore, we propose to place the new bacterium into a new genus and species for which the name Tabrizicola aquatica gen. nov. and sp. nov. is proposed. The type strain is RCRI19^T (=BCCM/LMG 25773^T = JCM 17277^T = KCTC 23724^T).     

Two novel species Enterococcus lemanii sp. nov. and Enterococcus eurekensis sp. nov., isolated from a swine-manure storage pit

A polyphasic taxonomic study using morphological, biochemical, chemotaxonomic and molecular genetic methods was performed on six strains of unknown Gram-positive, nonspore-forming, facultative anaerobic coccus-shaped bacteria isolated from a swine-manure storage pit. On the basis of the 16S rRNA, RNA polymerase α-subunit (rpoA) and 60 kDa chaperonin (cpn60) gene sequence analyses, it was shown that all the isolates were enterococci but formed two separate lines of descent. Pairwise 16S rRNA gene sequence comparisons demonstrated that the two novel organisms were most closely related to each other (97.9 %) and to Enterococcus aquimarinus (97.8 %). Both organisms contained major amounts of C_16:0, C_16:1 ω7c, C_16:1 ω7c, and C_18:1 ω7c/12t/9t as the major cellular fatty acids. Based on biochemical, chemotaxonomic and phylogenetic evidence, the names Enterococcus lemanii sp. nov. (type strain PC32^T = CCUG 61260^T = NRRL B-59661^T) and Enterococcus eurekensis sp. nov. (type strain PC4B^T = CCUG 61259^T = NRRL B-59662^T) are proposed for these hitherto undescribed species.     

<Emphasis Type="Italic">Sphingomonas aeria</Emphasis> sp. nov. from indoor air of a pharmaceutical environment

A proteobacterial strain designated R1-3^T was isolated from indoor air of a pharmaceutical environment. Cells were Gram-stain-negative, oxidase- and catalase-positive, aerobic, motile and rod-shaped. Strain R1-3^T grew optimally at pH 7, 30 °C and in 0–2 % NaCl on R2A agar. The 16S rRNA gene sequence analysis indicated that strain R1-3^T belongs to the genus Sphingomonas, and is closely related to Sphingomonas paucimobilis ATCC 29837^T (98.4 % sequence similarity). However, the DNA–DNA relatedness between the two strains was 43 ± 5 % (reciprocal = 37 ± 3 %), which was well below the suggested level for species distinction. Sphingomonas yabuuchiae GTC868^T (97.7 % 16S rRNA gene sequence similarity) and Sphingomonas pseudosanguinis G1-2^T (97.6 %) were also found as distantly related taxa. Strain R1-3^T was sensitive to most of the tested antibiotics except for erythromycin and streptomycin. The major fatty acid was a summed feature consisting of C_18:1 ω7c and/or C_18:1 ω6c, and minor proportions of C_14:0 2-OH, C_16:0 and a summed feature consisting of C_16:1 ω7c and/or C_16:1 ω6c were also present. The DNA G + C content was 67.2 ± 1.0 mol%. The major polyamines were sym-homospermidine and spermidine. The major polar lipids were phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, and minor amounts of a sphingoglycolipid, a phospholipid, an aminoglycolipid and an unidentified lipid were also present. The phenotypic, phylogenetic and chemotaxonomic data not only supported the affiliation of strain R1-3^T to the genus Sphingomonas, but also distinguished R1-3^T from related species. On the basis of physiological, chemotaxonomic and phylogenetic evidences, strain R1-3^T clearly merits recognition as a novel species of Sphingomonas, for which the name Sphingomonas aeria sp. nov. is proposed. The type strain is R1-3^T (= KCTC 42061^T = JCM 19859^T).     

Recovery of cellulase activity after ethanol stripping in a novel pilot-scale unit

Recycling of enzymes has a potential interest during cellulosic bioethanol production as purchasing enzymes is one of the largest expenses in the process. By recycling enzymes after distillation, loss of sugars and ethanol are avoided, but depending on the distillation temperature, there is a potential risk of enzyme degradation. Studies of the rate of enzyme denaturation based on estimation of the denaturation constant K _D was performed using a novel distillation setup allowing stripping of ethanol at 50–65 °C. Experiments were performed in a pilot-scale stripper, where the effect of temperature (55–65 °C) and exposure to gas–liquid and liquid–heat transmission interfaces were tested on a mesophilic and thermostable enzyme mixture in fiber beer and buffer. Lab-scale tests were included in addition to the pilot-scale experiments to study the effect of shear, ethanol concentration, and PEG on enzyme stability. When increasing the temperature (up to 65 °C) or ethanol content (up to 7.5 % w/v), the denaturation rate of the enzymes increased. Enzyme denaturation occurred slower when the experiments were performed in fiber beer compared to buffer only, which could be due to PEG or other stabilizing substances in fiber beer. However, at extreme conditions with high temperature (65 °C) and ethanol content (7.5 % w/v), PEG had no enzyme stabilizing effect. The novel distillation setup proved to be useful for maintaining enzyme activity during ethanol extraction.     

An enzymatic method for the production of 6-oxohexanoic acid from 6-aminohexanoic acid by an enzyme oxidizing ω-amino compounds from Phialemonium sp. AIU 274

An enzymatic method for 6-oxohexanoic acid production was developed using 6-aminohexanoic acid and an ω-amino group-oxidizing enzyme (ω-AOX) from Phialemonium sp. AIU 274. 6-Oxohexanoic acid was produced from 6-aminohexanoic acid with 100% yield by incubation with 0.3 U of the ω-AOX and 20 U of catalase at 30 °C for 30 h in 0.1 M potassium phosphate buffer (pH 7.0).     

Theoretical Study of the Conformations of Pustulan [(1⇒6)-β-D)-Glucan]

Abstract

The total potential energy including nonbondedJuntorsional and hydrogen bond contributions has been computed for pustulan, a (1?6) linked β-D-glucan polysaccharide, as a function of rotational angles φ, ψ, and ω The (φ, ψ, ω)-space contains many local minima and at least three distinct deep minima. Two minima at (φ, ψ, ω)=(25°,190°,gg) and (φ, ψ, ω)=(65°,150°,gg) of almost equal energies have helical parameters (n=5.2, A=1.0Å) and (n=3.2, h= 1.5Å), respectively. A third minimum at (φ, ψ, ω)=(40°,70°gt) leads to an extended zig-zag structure (n=2.2, h=2.2Å). Energy maps obtained for gentiobiose, the disaccharide of pustulan, also reveal many local minima and the small energy differences among them indicate that gentiobiose is extremely flexible. Gentiodextrins, a family of cyclic molecules of (l?6)-β-D- glucose residues, were also studied. Conformations free from steric hindrance were found for cyclic molecules with three to six glucose residues.     

Erratum to: Two novel species Enterococcus lemanii sp. nov. and Enterococcus eurekensis sp. nov., isolated from a swine-manure storage pit

A polyphasic taxonomic study using morphological, biochemical, chemotaxonomic and molecular genetic methods was performed on six strains of an unknown Gram-positive, nonspore-forming, facultative anaerobic coccus-shaped bacterium isolated from a swine-manure storage pit. On the basis of 16S rRNA, RNA polymerase-subunit (rpoA), and the 60-kilodalton chaperonin (cpn60) gene sequence analyses, it was shown that all the isolates were enterococci but formed two separate lines of descent. Pairwise 16S rRNA sequence comparisons demonstrated that the two novel organisms were most closely related to each other (97.9 %) and to Enterococcus aquimarinus (97.8 %). Both organisms contained major amounts of C_16:0, C_16:1 ω7c, and C_18:1 ω7c/12t/9t as the major cellular fatty acids. Based on biochemical, chemotaxonomic, and phylogenetic evidence, the names Enterococcus lemanii sp. nov. (type strain PC32^T = CCUG 61260^T = NRRL B-59661^T) and Enterococcus eurekensis sp. nov. (type strain PC4B^T = CCUG 61259^T = NRRL B-59662^T) are proposed for the hitherto undescribed species.     

Simulated dynamics of Ne@C60 aggregates beyond dissociation

Molecular dynamics (MD) computer simulations are utilized to better understand the dynamics of small (N = 5) endohedral Ne@C₆₀ aggregates. Multiple runs at various temperatures are used to increase the reliability of our statistics. The aggregate holds together until somewhere between T = 1150 and 1200 K, where it dissociates, showing no intermediate sign of melting or fullerene disintegration. When the temperature is increased to around T = 4000 K, the encapsulated neon atoms begin to leave the aggregate, with the fullerene molecules still remaining intact. At temperatures near T = 4400 K, thermal disintegration of the fullerenes preempts the aggregate dissociation. Above this temperature neon atoms are more quickly released and the fullerenes form a larger connected structure, with bonding taking place in atom pairs from different original fullerene molecules. Escape constants and half lives are calculated for the temperature range 4000 K ≤ T ≤ 5000 K. The agreements and disagreements of results of this work with experiments suggest that classical MD simulations are useful in describing fullerene systems at low temperatures and near disintegration, but require development of new techniques before it is possible to accurately model windowing at temperatures below T = 3000 K.     

Computational study of dynamic motions and possibility of crossing between surfaces in 3-hydroxy-5-(1H-pyrrol-2-yl)-2H-pyrrol-2-one

Potential energy surfaces (PESs) for tautomerism and two dynamic motions of 3-hydroxy-5-(1H-pyrrol-2-yl)-2H-pyrrol-2-one and its tautomer were calculated using density functional theory. Calculated energies confirm that T1 is 10.95 kJ mol^? 1 more stable than T2. Dynamic study of possible motions shows the high energy-level transition state at D8 = 90° for ring rotation and at D15 = 80° and 90° for rotation of OH bond, respectively, in T1 and T2. In addition, calculated rate constant for conversion of T1 to T2 (tautomerism) is 116 M^? 1 s^? 1, for relative rotations of rings in T1 and T2 are, respectively, 5.62 × 10^? 2 and 1.53 M^? 1 s^? 1 and for rotations of OH bond in T1 and T2 are, respectively, 3.56 × 10⁵ and 6.15 × 10⁴ M^? 1 s^? 1. In the next part of the study, orbital occupancies, natural bond orbitals (NBO) charges and hybridisation in relative rotation of rings and internal reaction coordinate (IRC) steps have been extracted to study the possibility of level crossing. These data show that PESs for IRC and ring rotation have different symmetries. So that these two potential curves cannot have effective non-adiabatic level crossing. However, the levels are weakly avoided or the possibility of level crossing is higher than related system because the energy difference between their barrier energies is not very high.     

Temperature affects the limitation of Daphnia magna by eicosapentaenoic acid,and the fatty acid composition of body tissue and eggs

1. Poikilothermic animals incorporate more polyunsaturated fatty acids (PUFAs) into their cellular membranes as temperature declines, suggesting an increased sensitivity to PUFA limitation in cool conditions. To test this we raised Daphnia magna at different temperatures and investigated the effect of varying dietary PUFA on life history parameters (i.e. growth, reproduction) and the PUFA composition of body tissue and eggs. 2. Upon a PUFA‐rich diet (Cryptomonas sp.) females showed higher concentrations of several ω3 PUFAs in their body tissue at 15 °C than at 20 °C and 25 °C, indicating a greater structural requirement for ω3 PUFAs at low temperature. Their eggs had an equal but higher concentration of ω3 PUFAs than their body tissue. 3. In a life history experiment at 15 and 20 °C we supplemented a diet of a PUFA‐free cyanobacterium with the ω3 PUFA eicosapentaenoic acid (EPA). The growth of D. magna was more strongly EPA limited at low temperature. A greater requirement for structural EPA at 15 °C was indicated by a steeper increase in somatic EPA content with dietary EPA compared to 20 °C. 4. At 20 °C the development of eggs to successful hatching was high when EPA was supplied to the mothers. At 15 °C the hatching success was generally poor, despite of a higher maternal provision of EPA to eggs, compared to that at 20 °C, suggesting that EPA alone was insufficient for proper neonatal development at the low temperature. The growth of offspring from mothers raised at 20 °C without EPA supplementation was very low, indicating that the negative effects of EPA deficiency can be carried on to the next generation. 5. The fatty acid composition of Daphnia sp. in published field studies shows increasing proportions of saturated fatty acids with increasing environmental temperature, whereas ω3 PUFAs and EPA show no clear pattern, suggesting that variations in dietary PUFA may mask temperature‐dependent adjustments in ω3 PUFA concentrations of cladocerans in nature.     

Devosia epidermidihirudinis sp. nov. isolated from the surface of a medical leech

A Gram-negative, rod-shaped organism, isolated from the surface of the medical leech Hirudo verbana was characterized phenotypically and genotypically. The calculated 16S rRNA gene sequence similarities to those of the most closely related species grouped strain E84^T into the genus Devosia showing the highest similarities to Devosia limi (98.1 %), followed by Devosia psychrophila (97.9 %), Devosia neptuniae (97.3 %), and Devosia glacialis (97.5 %). Chemotaxonomic analyses showed that the major quinone was ubiquinone Q-10. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol and three glycolipids. The major fatty acid profile consisted of C_18:1 ω7c 11-methyl, C_19:0 cyclo ω8c, and C_16:0, C_18:0 and C_18:1 ω7c with C_18:0 3OH as hydroxylated fatty acid. This profile is very similar to those of the patterns reported for the already described Devosia species. The results of DNA–DNA hybridization, physiological and biochemical tests allowed both genotypic and phenotypic differentiation of strain E84^T from all other Devosia species suggesting a novel species for which the name Devosia epidermidihirudinis sp. nov. is proposed, with the type strain E84^T (=CIP 110375^T = LMG 26909^T = CCM 8398^T).     

Sphingobacterium pakistanensis sp. nov., a novel plant growth promoting rhizobacteria isolated from rhizosphere of Vigna mungo

The taxonomic status of a bacterium, strain NCCP-246^T, isolated from rhizosphere of Vigna mungo, was determined using a polyphasic taxonomic approach. The strain NCCP-246^T can grow at 16–37 °C (optimum 32 °C), at pH ranges of 6–8 (optimum growth occurs at pH 7) and in 0–4 % (w/v) NaCl. Phylogenetic analysis based upon on 16S rRNA gene sequence comparison revealed that strain NCCP-246^T belonged to genus Sphingobacterium. Strain NCCP-246^T showed highest similarity to the type strain of Sphingobacterium canadense CR11^T (97.67 %) and less than 97 % with other species of the genus. The DNA–DNA relatedness value of strain NCCP-246^T with S. canadense CR11^T and Sphingobacterium thalpophilum JCM 21153^T was 55 and 44.4 %, respectively. The chemotaxonomic data revealed the major menaquinone as MK-7 and dominant cellular fatty acids were summed feature 3 [C_16:1 ω7c/C_16:1 ω6c] (37.07 %), iso-C_15:0 (28.03 %), C_16:0 (11.85 %), C_17:0 cyclo (8.84 %) and C_14:0 (2.42 %). The G+C content of the strain was 39.2 mol%. On the basis of DNA–DNA hybridization, phylogenetic analyses, physiological and, biochemical data, strain NCCP-246^T can be differentiated from the validly named members of genus Sphingobacterium and thus represents as a new species, for which the name, Sphingobacterium pakistanensis sp. nov. is proposed with the type strain NCCP-246^T (= JCM18974 ^T = KCTC 23914^T).