Ocean Sampling Day was initiated by the EU-funded Micro B3 (Marine Microbial Biodiversity, Bioinformatics, Biotechnology) project to obtain a snapshot of the marine microbial biodiversity and function of the world’s oceans. It is a simultaneous global mega-sequencing campaign aiming to generate the largest standardized microbial data set in a single day. This will be achievable only through the coordinated efforts of an Ocean Sampling Day Consortium, supportive partnerships and networks between sites. This commentary outlines the establishment, function and aims of the Consortium and describes our vision for a sustainable study of marine microbial communities and their embedded functional traits.

No abstract

Several strains isolated from Cytisus villosus nodules have been characterized based on their diverse genetic, phenotypic and symbiotic characteristics. According to 16S rRNA gene sequence analysis, the isolates formed a group that was closely related to Bradyrhizobium canariense BTA-1 T with 99.4 % similarity. Analysis of three housekeeping genes, recA, atpD and glnII, suggested that the C. villosus strains represent a novel Bradyrhizobium species most closely related to B. canariense BTA-1 T with similarities of 94.2, 96.7 and 94.5 %, respectively. All these differences were congruent with DNA-DNA hybridization analysis, which revealed 31 % relatedness between a representative strain (CTAW11 T ) isolated from C. villosus nodules and B. canariense BTA-1 T . Phenotypic differences among the strains isolated from C. villosus and B. canariense were based on assimilation of carbon and nitrogen sources. The nodC and nifH genes of strain CTAW11T were phylogenetically related to those of strains belonging to bv.genistearum and divergent from those of bv. glycinearum and, accordingly, they do not nodulate soybean. Based on the genotypic and phenotypic data obtained in this study, our strains should be classified as representatives of a novel species for which the name Bradyrhizobium cytisi sp. nov. is proposed; the type strain is CTAW11 T (5LMG 25866Hairybroom (Cytisus villosus Pourr., syn. Cytisus triflorus L'Hérit) is a perennial shrub of the Fabaceae family within the tribe Genisteae. This legume has potential for use in revegetation programmes due to its ability to establish N 2 -fixing symbiosis with slow-growing bacteria of the genus Bradyrhizobium (Weir et al., 2004; Rodríguez-Echeverría & Pérez-Fernández, 2005).The genus Bradyrhizobium currently contains several species, most of which have been isolated from nodules of diverse legumes. However, two species [Bradyrhizobium betae (Rivas et al., 2004) and Bradyrhizobium iriomotense (Islam et al., 2008), the name of which was recently validly published (Islam et al., 2010)] were isolated from plant tumours.In the present work, six strains isolated from effective nodules of Cytisus villosus growing in the Moroccan Rif were analysed by using molecular and phenotypic methods. Results showed that they should be classified as representatives of a novel Bradyrhizobium species.The six strains were isolated from effective nodules of C. villosus on yeast-mannitol agar (YMA) after incubation for 7 days at 28 u C according to Vincent (1970). Nodules were collected in the central-western region of the Moroccan Rif mountains (altitude of about 1600 m). All strains showed a slow growth rate and form mucoid Bradyrhizobium-like colonies.Amplification and sequencing of the 16S rRNA gene were done using the two opposing primers 41f and 1488r described previously by Herrera-Cervera et al. (1999). Partial sequences of atpD, recA and glnII genes were obtained using the primers described by Vinuesa et al.Abbreviations: ML, maximum-likelihood; MP, maximum-parsimony; NJ, neighbour-joinin...

No abstract

Astragalus gombiformis is a desert symbiotic nitrogen-fixing legume of great nutritional value as fodder for camels and goats. However, there are no data published on the rhizobial bacteria that nodulate this wild legume in northern Africa. Thirty-four rhizobial bacteria were isolated from root nodules of A. gombifomis grown in sandy soils of the South-Eastern of Morocco. Twenty-five isolates were able to renodulate their original host and possessed a nodC gene copy. The phenotypic and genotypic characterizations carried out illustrated the diversity of the isolates. Phenotypic analysis showed that isolates used a great number of carbohydrates as sole carbon source. However, although they were isolated from arid sandy soils, the isolates do not tolerate drought stress applied in vitro. The phenotypic diversity corresponded mainly to the diversity in the use of some carbohydrates. The genetic analysis as assessed by repetitive extragenic palindromic (REP)-polymerase chain reaction (PCR) showed that the isolates clustered into 3 groups at a similarity coefficient of 81 %. The nearly-complete 16S rRNA gene sequence from a representative strain of each PCR-group showed they were closely related to members of the genus Mesorhizobium of the family Phyllobactericeae within the Alphaproteobacteria. Sequencing of the housekeeping genes atpD, glnII and recA, and their concatenated phylogenetic analysis, showed they are closely related to Mesorhizobium camelthorni. Sequencing of the symbiotic nodC gene from each strain revealed they had 83.53 % identity with the nodC sequence of the type strain M. camelthorni CCNWXJ 40-4(T.)