Nitrification and nitrifying bacteria in the lower Seine River and estuary (France)

The Achères wastewater treatment plant, located just downstream of Paris, discharges its effluents into the lower Seine River. The effluents contain large numbers of heterotrophic bacteria, organic matter, and ammonium and are a source of nitrifying bacteria. As a result, degradation of organic matter by heterotrophic bacteria and subsequent oxygen depletion occur immediately downstream of the effluent outlet, whereas nitrifying bacteria apparently need to build up a significant biomass before ammonium oxidation significantly depletes the oxygen. We quantified the potential total nitrifying activity and the potential activities of the ammonia- and nitrite-oxidizing communities along the Seine River. In the summer, the maximum nitrifying activity occurs in the upper freshwater estuary, approximately 200 km downstream of Achères. The quantities of nitrifying bacteria, based on amoA gene copy numbers, and of Nitrobacter organisms, based on 16S rRNA gene copy numbers, were correlated with the potential nitrifying activities. The species composition of ammonia-oxidizing bacteria was investigated at two sites: the Triel station just downstream from Achères (km 84) and the Seine freshwater estuary at the Duclair station (km 278). By means of PCR primers targeting the amoA gene, a gene library was created. Phylogenetic analysis revealed that the majority of the analyzed clones at both sites were affiliated with the genus NITROSOMONAS: The Nitrosomonas oligotropha- and Nitrosomonas urea-related clones represented nearly 81% of the community of ammonia-oxidizing bacteria at Triel and 60% at Duclair. Two other ammonia-oxidizing clusters of the beta subclass of the Proteobacteria, i.e., Nitrosomonas europaea- and Nitrosospira-like bacteria, were found in smaller numbers. The major change in the ammonia-oxidizing community between the two stations along the Seine River-upper estuary continuum was the replacement of the N. oligotropha- and N. urea-related bacteria by the Nitrosospira-affiliated bacteria. Although the diversities of the ammonia oxidizers appear to be similar for the two sites, only half of the restriction patterns are common to both sites, which could be explained by the differences in ammonium concentrations, which are much lower in the upper estuary than in the river at the effluent outlet. These results imply a significant immigration and/or selection of the ammonia-oxidizing bacterial population along the continuum of the Seine River from Paris to the estuary.     

Mikrocytos roughleyi taxonomic affiliation leads to the genus Bonamia (Haplosporidia)

Microcell-type parasites of oysters are associated with a complex of diseases in different oyster species around the world. The etiological agents are protists of very small size that are very difficult to characterize taxonomically. Associated lesions may vary according to the host species, and their occurrence may be related to variations in tissue structure. Lesion morphology cannot be used to distinguish the different agents involved. Ultrastructural observations on Mikrocytos roughleyi revealed similarities with Bonamia spp., particularly in regard to the presence of electron-dense haplosporosomes and mitochondria, whose absence from M. mackini also indicate that M. roughleyi and M. mackini are not congeneric. A partial small subunit (ssu) rRNA gene sequence of M. roughleyi was determined. This partial sequence, 951 nucleotides in length, has 95.2 and 98.4% sequence similarities with B. ostreae and B. exitiosus ssu rDNA sequences, respectively. Polymorphisms among the ssu rDNA sequences of B. ostreae, B. exitiosus and M. roughleyi allowed identification of restriction enzyme digestion patterns diagnostic for each species. Phylogenetic analysis based on the ssu rDNA data suggested that M. roughleyi belongs in the phylum Haplosporidia and that it is closely related to Bonamia spp. On the basis of ultrastructural and molecular considerations, M. roughleyi should be considered a putative member of the genus Bonamia.     

Correction to: Preliminary insights into the population characteristics and distribution of reef (Mobula alfredi) and oceanic (M. birostris) manta rays in French Polynesia

Coral Reefs - This erratum has been initiated as many corrections which were submitted during proofing were overlooked by vendor.     

Les urgences andrologiques en milieu urbain au Cameroun : aspects cliniques et thérapeutiques

Goal

Describe clinical and therapeutic aspects of andrologic emergencies in an urban area, received in a university teaching hospital in Cameroon.

Methodology

We prospectively studied during 36 months all andrologic emergencies received at Laquintinie Hospital of Douala.

Results

We had a total of 291 patients. The mean age was 42.50 years. Most of our patients?? age was between 0 and 45 years. The most frequent lesion was genito-urinary trauma (51.50%) and uro-genital infections (23.71%). Priapism and torsion of the spermatic cord were also frequent. We carried out 185 emergency surgical interventions. Exploration and suture of wounds of the external genitalia (38.91%) and the exploratory scrototomy (21.62%) were the main emergency procedures.

Conclusion

Genito-urinary trauma are the most encountered andrologic emergencies in an urban area of Cameroon. Priapism and torsion of the spermatic cord were not rare.     

Le metabolisme du soufre dans la rhumerie

Résumé Le rhum, comparativement aux autres eaux-de-vie, se singularise par la variété et les teneurs relativement élevées de composés organo-soufrés qu'il contient. La composition de la canne à sucre ainsi que les apports de sulfate et d'acide sulfurique tout au long de la filière industrielle font que les milieux de fermentations sont riches en dérivés soufrés. En aval de la distillerie, la méthanisation des effluents pose le problème d'un équilibre précaire entre les flores méthanigène et sulfato-réductrice. La fraction organo-soufrée mérite une étude approfondie et systématique, car elle présente un intérêt analytique et organoleptique pour la caractérisation des rhums.

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The metabolism of sulphur during the manufacture of rum

Summary Rum distinguishes itself from other brandies by the variety and the relatively high content of organic sulphur compounds. Composition of sugar-cane as well as additions of sulphate and sulphuric acid along the industrial process gives fermentation media that are rich in sulphur-compounds. Downstream from the distillery, biomethanation of effluents is difficult because of a precarious equilibrium between the methanogenic and the sulphate-reducing bacterial floras. The organic sulphur-fraction requires a systematic study because the latter are involved in the organoleptic properties of rums.

     

The presence of two populations of sensory-type cells in the pineal organ of the five-bearded rockling,Ciliata mustela L. (Teleostei)

The pineal organ of the five-bearded rockling, Ciliata mustela L., was examined by means of electron microscopy. Two categories of sensory cells are described: 1) Sensory cells 1 (or photoreceptor cells sensu stricto) showing the characteristic ultrastructure of photoreceptor cells with a well-developed receptor pole (outer segment) and a transmitter pole (ribbon-type synapse in the basal pedicle contacting dendritic processes), and a segmental organization of organelles. 2) Sensory cells 2 (or photoneuroendocrine cells) displaying no particular segmentation. The ultrastructure of the receptor pole (outer segment) is variable in shape (with either long or short disks) and in the number of disks; some outer segments are simple cilia of the 9 + 0 type. This second cell category is rich in smooth endoplasmic reticulum, beta-particles of glycogen, dense inclusions of variable size and content, and dense-core vesicles 130 nm in diameter. These cells have an extended contact area with the perivascular space. The functional significance of both cell categories is discussed in terms of the known physiological responses of the pineal organ. A possible confusion in identification of interstitial cells and neuroendocrine cells in some teleost species is discussed.