Minimum Information about a Biosynthetic Gene cluster

A wide variety of enzymatic pathways that produce specialized metabolites in bacteria, fungi and plants are known to be encoded in biosynthetic gene clusters. Information about these clusters, pathways and metabolites is currently dispersed throughout the literature, making it difficult to exploit. To facilitate consistent and systematic deposition and retrieval of data on biosynthetic gene clusters, we propose the Minimum Information about a Biosynthetic Gene cluster (MIBiG) data standard.Chemistry and Chemical Biolog

Fluorescence insitu hybridization of Microcystis strains producing microcystin using specific mRNA probes

International audienceCyanobacteria are ubiquitous micro-organisms that can produce toxic compounds, the cyanotoxins. The monitoring of such producers in the environment is of prime importance for human health. An attractive technology for such monitoring is fluorescence insitu hybridization (FISH), which allows the detection and enumeration of environmental micro-organisms. We present here the application of tyramide signal amplification fluorescence insitu hybridization (TSA-FISH) to the detection of microcystin-producing Microcystis strains. We used a 16S rRNA-specific probe, MICR3, to specifically label and observe by epifluorescence microscopy Microcystis aeruginosa strains. Using confocal laser scanning microscopy and a specific probe, MCYA, targeting the mcyA mRNA we have labelled M.aeruginosa PCC 7806, which produces microcystins. Microcystis aeruginosa PCC 7005 which does not produce microcystins is not labelled by this probe. Furthermore, we show here that this specific mRNA labelling in M.aeruginosa PCC 7806 is enhanced in cells illuminated for 1h just after a dark period of cultivation of 24h, conditions in which the mcyA gene is up regulated. The data presented here might be applicable to the monitoring of toxic Microcystis strains in the environment. Significance and Impact of the StudyCyanobacteria producing toxic compounds (cyanotoxins) are present in the environment and in water bodies. Their presence poses a threat on human and animal health. It is thus important to detect, identify and enumerate these toxic Cyanobacteria. Using tyramide signal amplification fluorescence insitu hybridization (TSA-FISH) and specific probes, with confocal laser scanning microscopy, we have specifically detected Microcystis strains producing microcystin toxins. The data presented here might be applied to the monitoring of water bodies at early stages and all along the formation of Microcystis blooms

Interactions entre objets biologiques et surfaces nanostructurées : quelques illustrations

Les interactions entre les objets biologiques (protéines, cellules, bactéries, ...) et les surfaces jouent un rôle primordial en sciences du vivant, dans le domaine biomédical notamment. Le présent texte est plus particulièrement focalisé sur l'échelle nanométrique de ces interactions. Des surfaces nanostructurées, tant du point de vue chimique que topographique, sont de bons outils pour analyser de telles interactions. Ainsi, quelques aspects concernant : (i) l'adsorption de protéines sur des surfaces moléculaires auto-organisées ou autres surfaces nanostructurées, (ii) l'adhésion bactérienne sur des surfaces polymères nano-organisées, (iii) l'adhésion cellulaire et bactérienne sur des surfaces à nanotopographie et chimie contrôlées (surfaces patternées, arrangement compact de nanobilles, ...), sont brièvement présentés et discutés