Juxtaposed membranes underpin cellular adhesion and display unilateral cell division of multicellular magnetotactic prokaryotes.

Multicellular magnetotactic prokaryotes (MMPs) exhibit peculiar coordination of swimming along geomagnetic field lines. Approximately 40-80 cells assemble, with a helical geometry or axisymmetry, into spherical or ellipsoidal MMPs respectively. To contribute to a comprehensive understanding of bacterial multicellularity here we took multiple microscopic approaches to study the diversity, assembly, reproduction and motility of ellipsoidal MMPs.

Identification of novel species of marine magnetotactic bacteria affiliated with Nitrospirae phylum.

Magnetotactic bacteria (MTB) are a group of Gram-negative bacteria characterized by synthesizing magnetosomes and swimming along geomagnetic field lines. Phylogenetically, they belong to different taxonomic lineages including Proteobacteria, Nitrospirae, Omnitrophica, Latescibacteria and Planctomycetes phyla on the phylogenetic tree. To date, six Nitrospirae MTB phylotypes have been identified from freshwater or low-salinity environments and described in the literature.

Glycosylate and move! The glycosyltransferase Maf is involved in bacterial flagella formation.

The flagella of various Gram-negative bacteria are decorated with diverse glycan structures, amongst them nonulosonic acids related to the sialic acid family. Although nonulosonic sugar biosynthesis pathways have been dissected in various pathogens, the enzymes transferring the sugars onto flagellin are still poorly characterized. The deletion of genes coding for motility associated factors (Mafs) found in many pathogenic strains systematically gives rise to nonflagellated bacteria lacking specific nonulosonic sugars on the flagellins, therefore, relating Maf function to flagellin glycosylation and bacterial motility.

The chimeric nature of the genomes of marine magnetotactic coccoid-ovoid bacteria defines a novel group of Proteobacteria.

Magnetotactic bacteria (MTB) are a group of phylogenetically and physiologically diverse Gram-negative bacteria that synthesize intracellular magnetic crystals named magnetosomes. MTB are affiliated with three classes of Proteobacteria phylum, Nitrospirae phylum, Omnitrophica phylum and probably with the candidate phylum Latescibacteria. The evolutionary origin and physiological diversity of MTB compared with other bacterial taxonomic groups remain to be illustrated.

Genomic and physiological analysis reveals versatile metabolic capacity of deep-sea Photobacterium phosphoreum ANT-2200.

Bacteria of the genus Photobacterium thrive worldwide in oceans and show substantial eco-physiological diversity including free-living, symbiotic and piezophilic life styles. Genomic characteristics underlying this variability across species are poorly understood. Here we carried out genomic and physiological analysis of Photobacterium phosphoreum strain ANT-2200, the first deep-sea luminous bacterium of which the genome has been sequenced.

Opposite and Coordinated Rotation of Amphitrichous Flagella Governs Oriented Swimming and Reversals in a Magnetotactic Spirillum.

Unlabelled: Current knowledge regarding the mechanism that governs flagellar motor rotation in response to environmental stimuli stems mainly from the study of monotrichous and peritrichous bacteria. Little is known about how two polar flagella, one at each cell pole of the so-called amphitrichous bacterium, are coordinated to steer the swimming. Here we fluorescently labeled the flagella of Magnetospirillum magneticum AMB-1 cells and took advantage of the magnetically controllable swimming of this bacterium to investigate flagellar rotation in moving cells.

Comparative genomic analysis provides insights into the evolution and niche adaptation of marine Magnetospira sp. QH-2 strain.

Magnetotactic bacteria (MTB) are capable of synthesizing intracellular organelles, the magnetosomes, that are membrane-bounded magnetite or greigite crystals arranged in chains. Although MTB are widely spread in various ecosystems, few axenic cultures are available, and only freshwater Magnetospirillum spp. have been genetically analysed.

Lactate dehydrogenase A promotes communication between carbohydrate catabolism and virulence in Bacillus cereus.

The diarrheal potential of a Bacillus cereus strain is essentially dictated by the amount of secreted nonhemolytic enterotoxin (Nhe). Expression of genes encoding Nhe is regulated by several factors, including the metabolic state of the cells. To identify metabolic sensors that could promote communication between central metabolism and nhe expression, we compared four strains of the B.

Crystal structure of inactivated Thermotoga maritima invertase in complex with the trisaccharide substrate raffinose.

Thermotoga maritima invertase (beta-fructosidase), a member of the glycoside hydrolase family GH-32, readily releases beta-D-fructose from sucrose, raffinose and fructan polymers such as inulin. These carbohydrates represent major carbon and energy sources for prokaryotes and eukaryotes. The invertase cleaves beta-fructopyranosidic linkages by a double-displacement mechanism, which involves a nucleophilic aspartate and a catalytic glutamic acid acting as a general acid/base.

The Clostridium botulinum GerAB germination protein is located in the inner membrane of spores.

Clostridium botulinum dormant spores germinate in presence of l-alanine via a specific receptor composed of GerAA, GerAB and GerAC proteins. In Bacillus subtilis spores, GerAA and GerAC proteins were located in the inner membrane of the spore. We studied the location of the GerAB protein in C.

The three-dimensional structure of invertase (beta-fructosidase) from Thermotoga maritima reveals a bimodular arrangement and an evolutionary relationship between retaining and inverting glycosidases.

Thermotoga maritima invertase (beta-fructosidase) hydrolyzes sucrose to release fructose and glucose, which are major carbon and energy sources for both prokaryotes and eukaryotes. The name "invertase" was given to this enzyme over a century ago, because the 1:1 mixture of glucose and fructose that it produces was named "invert sugar." Despite its name, the enzyme operates with a mechanism leading to the retention of the anomeric configuration at the site of cleavage.