Massilia norwichensis sp. nov., isolated from an air sample

A Gram-negative, rod-shaped and motile bacterial isolate, designated strain NS9T, isolated from air of the Sainsbury Centre for Visual Arts in Norwich, UK, was subjected to a polyphasic taxonomic study including phylogenetic analyses based on partial 16S rRNA, gyrB and lepA gene sequences and phenotypic characterization. The 16S rRNA gene sequence of NS9T identified Massilia haematophila CCUG 38318T, M. niastensis 5516S-1T (both 97.7% similarity), M. aerilata 5516S-11T (97.4 %) and M. tieshanensis TS3T (97.4 %) as the next closest relatives. In partial gyrB and lepA sequences, NS9T shared the highest similarities with M. haematophila CCUG 38318T (94.5 %) and M. aerilata 5516-11T (94.3 %), respectively. These sequence data demonstrate the affiliation of NS9T to the genus Massilia. The detection of the predominant ubiquinone Q-8, a polar lipid profile consisting of the major compounds diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol and a polyamine pattern containing 2- hydroxyputrescine and putrescine were in agreement with the assignment of strain NS9T to the genus Massilia. Major fatty acids were summed feature 3 (C16 : 1v7c and/or iso-C15 : 0 2-OH), C16 : 0, C18 : 1v7c and C10 : 0 3-OH. Dissimilarities in partial lepA and gyrB gene sequences as well as results from DNA–DNA hybridizations demonstrate that strain NS9T is a representative of an as-yet undescribed species of the genus Massilia that is also distinguished from its close relatives based on physiological and biochemical traits. Hence, we describe a novel species, for which we propose the name Massilia norwichensis sp. nov., with the type strain NS9T (5CCUG 65457T5LMG 28164T)

Rubrobacter aplysinae sp. nov., isolated from the marine sponge Aplysina aerophoba

A Gram-stain-positive, non-spore-forming bacterium (strain RV113(T)) was isolated from the marine sponge Aplysina aerophoba. 16S rRNA gene sequence analysis showed that strain RV113(T) belongs to the genus Rubrobacter, and is related most closely to Rubrobacter bracarensis VF70612_S1(T) (96.9% similarity) and more distantly related (<93%) to all other species of the genus Rubrobacter. The peptidoglycan diamino acid was lysine. Strain RV113(T) exhibited a quinone system with menaquinone MK-8 as the predominant compound. The polar lipid profile of strain RV113(T) consisted of the major compounds phosphatidylglycerol and two unidentified phosphoglycolipids. The major fatty acid was anteiso-C17 : 0ω9c. These chemotaxonomic traits are in agreement with those of other species of the genus Rubrobacter. The results of physiological and biochemical tests allowed the clear phenotypic differentiation of strain RV113(T) from all recognized Rubrobacter species. Strain RV113(T) is thus considered to represent a novel species, for which the name Rubrobacter aplysinae sp. nov. is proposed. The type strain is RV113(T) ( = DSM 27440(T) = CECT 8425(T))

Actinokineospora spheciospongiae sp. nov., isolated from the marine sponge Spheciospongia vagabunda

A Gram-positive staining, aerobic organism, isolated from the the Red Sea sponge Spheciospongia vagabunda was investigated for its taxonomic position. Based on 16S rRNA gene sequence analysis strain EG49T was most closely related to Actinokineospora cibodasensis and Actinokineospora baliensis (both 97.3%) and Actinokineospora diospyrosas and Actinokineospora auranticolor (both 97.0%). The 16S rRNA gene sequence similarity to all other Actinokineospora species was < 97.0 %. The quinone system of strain EG49T contains the menaqinone MK-9(H4), (47%), MK-9(H6), (27%) and MK-9(H2), (15%) in major amounts. Minor amounts of MK-7(H4), (2%), MK-9(H0), (1%), MK-9(H8) (3%) and MK-10(H4) (3%) were detected as well in addition to MK-8(H4), MK-8(H6), MK-10(H2) and MK-10(H6) (all <1%). The diagnostic diaminoacid of the peptidoglycan is meso-diaminopimelic acid. In the polar lipid profile, diphosphatidylglycerol, phosphatidylethanolamine, and hydroxyl-phosphatidylethanolamine are predominant. Phosphatidylinositol-mannoside, two unidentified phospholipids and two glycoglipids as well as one aminoglycolipid, one aminolipid and one unidentified lipid are found in addition. Fatty acid profile composed of mainly iso-branched fatty acids: iso-C16:0, iso-C14:0, iso-C15:0, and iso-C16:1 H. All these data clearly supported the allocation of the strain to the genus Actinokineospora. In addition, the results of physiological and biochemical tests also allowed phenotypic differentiation of strain EG49T from the most closely related Actinokineospora species. Strain EG49T represents a new species of the genus Actinokineospora, for which we propose the name Actinokineospora spheciospongiae sp. nov., with strain EG49T (= DSM 45935T = CCM 8480T = LMG 27700T) as the type strain

The abundance of endofungal bacterium Rhizobium radiobacter (syn. Agrobacterium tumefaciens) increases in its fungal host Piriformospora indica during the tripartite sebacinalean symbiosis with higher plants

Rhizobium radiobacter (syn. Agrobacterium tumefaciens, syn. "Agrobacterium fabrum") is an endofungal bacterium of the fungal mutualist Piriformospora (syn. Serendipita) indica (Basidiomycota), which together form a tripartite Sebacinalean symbiosis with a broad range of plants. R. radiobacter strain F4 (RrF4), isolated from P. indica DSM 11827, induces growth promotion and systemic resistance in cereal crops, including barley and wheat, suggesting that R. radiobacter contributes to a successful symbiosis. Here, we studied the impact of endobacteria on the morphology and the beneficial activity of P. indica during interactions with plants. Low numbers of endobacteria were detected in the axenically grown P. indica (long term lab-cultured, lcPiri) whereas mycelia colonizing the plant root contained increased numbers of bacteria. Higher numbers of endobacteria were also found in axenic cultures of P. indica that was freshly re-isolated (riPiri) from plant roots, though numbers dropped during repeated axenic re-cultivation. Prolonged treatments of P. indica cultures with various antibiotics could not completely eliminate the bacterium, though the number of detectable endobacteria decreased significantly, resulting in partial-cured P. indica (pcPiri). pcPiri showed reduced growth in axenic cultures and poor sporulation. Consistent with this, pcPiri also showed reduced plant growth promotion and reduced systemic resistance against powdery mildew infection as compared with riPiri and lcPiri. These results are consistent with the assumption that the endobacterium R. radiobacter improves P. indica's fitness and thus contributes to the success of the tripartite Sebacinalean symbiosis

Elementary processes governing the evolution of road networks

Urbanisation is a fundamental phenomenon whose quantitative characterisation is still inadequate. We report here the empirical analysis of a unique data set regarding almost 200 years of evolution of the road network in a large area located north of Milan (Italy). We find that urbanisation is characterised by the homogenisation of cell shapes, and by the stability throughout time of high-centrality roads which constitute the backbone of the urban structure, confirming the importance of historical paths. We show quantitatively that the growth of the network is governed by two elementary processes: (i) `densification', corresponding to an increase in the local density of roads around existing urban centres and (ii) `exploration', whereby new roads trigger the spatial evolution of the urbanisation front. The empirical identification of such simple elementary mechanisms suggests the existence of general, simple properties of urbanisation and opens new directions for its modelling and quantitative description.Comment: 10 pages, 6 figure

Employment mobility in high-technology agglomerations: the cases of Oxfordshire and Cambridgeshire

This paper examines labour market behaviour of the highly skilled in high-tech local economies, taking the UK examples of Oxfordshire and Cambridgeshire as case studies. It reports on data from a survey of members of three scientific institutes to compare rates of employee mobility in the two locations and considers the likely explanations and implications of those patterns

Network Structure and City Size

Network structure varies across cities. This variation may yield important knowledge about how the internal structure of the city affects its performance. This paper systematically compares a set of surface transportation network structure variables (connectivity, hierarchy, circuity, treeness, entropy, accessibility) across the 50 largest metropolitan areas in the United States. A set of scaling parameters are discovered to show how network size and structure vary with city size. These results suggest that larger cities are physically more inter-connected. Hypotheses are presented as to why this might obtain. This paper then consistently measures and ranks access to jobs across 50 US metropolitan areas. It uses that accessibility measure, along with network structure variables and city size to help explain journey-to-work time and auto mode share in those cities. A 1 percent increase in accessibility reduces average metropolitan commute times by about 90 seconds each way. A 1 percent increase in network connectivity reduces commute time by 0.1 percent. A 1 percent increase in accessibility results in a 0.0575 percent drop in auto mode share, while a 1 percent increase in treeness reduces auto mode share by 0.061 percent. Use of accessibility and network structure measures is important for planning and evaluating the performance of network investments and land use changes