Molecular biology: Fantastic toolkits to improve knowledge and application of acetic acid bacteria.

Acetic acid bacteria (AAB) are a group of gram-negative, obligate aerobic bacteria within the Acetobacteraceae family of the alphaproteobacteria class, which are distributed in a wide variety of different natural sources that are rich in sugar and alcohols, as well as in several traditionally fermented foods. Their versatile capabilities are not limited to producing acetic acid and brewing vinegar, as their names suggest. They can also be used for fixing nitrogen, yielding pigments and exopolysaccharides (EPS), and most typically, producing a variety of aldehydes, ketones and other organic acids from the incomplete oxidation of the corresponding alcohols and/or sugars (also referred to as oxidative fermentation).

Bacterial nanocellulose production and biomedical applications.

Bacterial nanocellulose (BNC) is a homopolymer of β-1,4 linked glycose, which is synthesized by using simple culturing methods to allow inexpensive and environmentally friendly small- and large-scale production. Depending on the growth media and types of fermentation methods, ultra-pure cellulose can be obtained with different physio-chemical characteristics. Upon biosynthesis, bacterial cellulose is assembled in the medium into a nanostructured network of glucan polymers that are semitransparent, mechanically highly resistant, but soft and elastic, and with a high capacity to store water and exchange gasses.

Two Major Clades of Bradyrhizobia Dominate Symbiotic Interactions with Pigeonpea in Fields of Côte d'Ivoire.

In smallholder farms of Côte d'Ivoire, particularly in the northeast of the country, (pigeonpea) has become an important crop because of its multiple beneficial facets. Pigeonpea seeds provide food to make ends meet, are sold on local markets, and aerial parts serve as forage for animals. Since it fixes atmospheric nitrogen in symbiosis with soil bacteria collectively known as rhizobia, also improves soil fertility and reduces fallow time.

Intracellular amorphous carbonates uncover a new biomineralization process in eukaryotes.

Until now, descriptions of intracellular biomineralization of amorphous inclusions involving alkaline-earth metal (AEM) carbonates other than calcium have been confined exclusively to cyanobacteria (Couradeau et al., 2012). Here, we report the first evidence of the presence of intracellular amorphous granules of AEM carbonates (calcium, strontium, and barium) in unicellular eukaryotes.

Gnomoniopsis smithogilvyi causes chestnut canker symptoms in Castanea sativa shoots in Switzerland.

A screening of Castanea sativa scions for grafting for the presence of endophytes showed that the opportunistic fungal pathogen Gnomoniopsis smithogilvyi was the most abundant member of the endophytic flora. This fungus is known as a pathogen affecting chestnut fruits in Italy and Australia. Here, we present evidence that it causes cankers very similar to the ones due to Cryphonectria parasitica infection on twigs and scions of chestnut trees.

Metaproteomics and ultrastructure characterization of Komagataeibacter spp. involved in high-acid spirit vinegar production.

Acetic acid bacteria (AAB) are widespread microorganisms in nature, extensively used in food industry to transform alcohols and sugar alcohols into their corresponding organic acids. Specialized strains are used in the production of vinegar through the oxidative transformation of ethanol into acetic acid. The main AAB involved in the production of high-acid vinegars using the submerged fermentation method belong to the genus Komagataeibacter, characterized by their higher ADH stability and activity, and higher acetic acid resistance (15-20%), compared to other AAB.

Updates on quick identification of acetic acid bacteria with a focus on the 16S-23S rRNA gene internal transcribed spacer and the analysis of cell proteins by MALDI-TOF mass spectrometry.

Acetic acid bacteria have attracted much attention over the past few years, due mainly to their metabolic traits that are of interest to the biotechnology industry. In addition, it turns out that their ecological habitats are almost unlimited since they have been found as symbionts in different insects and also as emerging opportunistic human pathogens. Very surprising is the finding that they colonize niches considered anaerobic, disproving the generalized statement that they are strict aerobes.

Zur (FurB) is a key factor in the control of the oxidative stress response in Anabaena sp. PCC 7120.

Iron and zinc are necessary nutrients whose homeostasis is tightly controlled by members of the ferric uptake regulator (FUR) superfamily in the cyanobacterium Anabaena sp. PCC7120. Although the link between iron metabolism and oxidative stress management is well documented, little is known about the connection between zinc homeostasis and the oxidative stress response in cyanobacteria.

Rapid identification of acetic acid bacteria using MALDI-TOF mass spectrometry fingerprinting.

Acetic acid bacteria (AAB) are widespread microorganisms characterized by their ability to transform alcohols and sugar-alcohols into their corresponding organic acids. The suitability of matrix-assisted laser desorption-time of flight mass spectrometry (MALDI-TOF MS) for the identification of cultured AAB involved in the industrial production of vinegar was evaluated on 64 reference strains from the genera Acetobacter, Gluconacetobacter and Gluconobacter. Analysis of MS spectra obtained from single colonies of these strains confirmed their basic classification based on comparative 16S rRNA gene sequence analysis.

Proteome analysis of Acetobacter pasteurianus during acetic acid fermentation.

Acetic acid bacteria (AAB) are Gram-negative, strictly aerobic microorganisms that show a unique resistance to ethanol (EtOH) and acetic acid (AcH). Members of the Acetobacter and Gluconacetobacter genera are capable of transforming EtOH into AcH via the alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) enzymes and are used for the industrial production of vinegar. Several mechanisms have been proposed to explain how AAB resist high concentrations of AcH, such as the assimilation of acetate through the tricarboxylic acid (TCA) cycle, the export of acetate by various transporters and modifications of the outer membrane.

Characterization of Neurospora crassa α-actinin.

α-Actinin, an actin-binding protein of the spectrin superfamily, is present in most eukaryotes except plants. It is composed of three domains: N-terminal CH-domains, C-terminal calcium-binding domain (with EF-hand motifs), and a central rod domain. We have cloned and expressed Neurospora crassa α-actinin as GST and GFP fusion proteins for biochemical characterization and in vivo localization, respectively.

Genome sequences of the high-acetic acid-resistant bacteria Gluconacetobacter europaeus LMG 18890T and G. europaeus LMG 18494 (reference strains), G. europaeus 5P3, and Gluconacetobacter oboediens 174Bp2 (isolated from vinegar).

Bacteria of the genus Gluconacetobacter are usually involved in the industrial production of vinegars with high acetic acid concentrations. We describe here the genome sequence of three Gluconacetobacter europaeus strains, a very common bacterial species from industrial fermentors, as well as of a Gluconacetobacter oboediens strain.

Overexpression of FurA in Anabaena sp. PCC 7120 reveals new targets for this regulator involved in photosynthesis, iron uptake and cellular morphology.

Previous genomic analyses of the filamentous nitrogen-fixing cyanobacterium Anabaena sp. PCC 7120 have identified three ferric uptake regulator (Fur) homologs with low sequence identities and probably different functions in the cell. FurA is a constitutive protein that shares the highest homology with Fur from heterotrophic bacteria and appears to be essential for in vitro growth.

Mutants of Anabaena sp. PCC 7120 lacking alr1690 and alpha-furA antisense RNA show a pleiotropic phenotype and altered photosynthetic machinery.

Fur proteins are global regulators present in all prokaryotes. In Anabaena sp. PCC 7120 FurA controls iron uptake and modulates an important set of genes related primarily to photosynthesis, nitrogen metabolism and oxidative stress defense.

Preventing mitochondrial fission impairs mitochondrial function and leads to loss of mitochondrial DNA.

Mitochondria form a highly dynamic tubular network, the morphology of which is regulated by frequent fission and fusion events. However, the role of mitochondrial fission in homeostasis of the organelle is still unknown. Here we report that preventing mitochondrial fission, by down-regulating expression of Drp1 in mammalian cells leads to a loss of mitochondrial DNA and a decrease of mitochondrial respiration coupled to an increase in the levels of cellular reactive oxygen species (ROS).

Specificity of commercial anti-spectrin antibody in the study of fungal and Oomycete spectrin: cross-reaction with proteins other than spectrin.

Spectrin was first described in erythrocytes where it forms a filamentous network in the cytoplasmic face of the plasma membrane and participates in the membrane's structural integrity in addition to controlling the lateral mobility of integral membrane proteins. In fungi, spectrin-like proteins have been described in the plasma membrane, concentrated mainly in the region of maximum apical expansion. This localization led to the idea of a spectrin based membrane skeleton in fungi participating in mechanical integrity of the plasma membrane, generating and maintaining cell polarity.

Inhibiting the mitochondrial fission machinery does not prevent Bax/Bak-dependent apoptosis.

Apoptosis, induced by a number of death stimuli, is associated with a fragmentation of the mitochondrial network. These morphological changes in mitochondria have been shown to require proteins, such as Drp1 or hFis1, which are involved in regulating the fission of mitochondria. However, the precise role of mitochondrial fission during apoptosis remains elusive.

Proteolytic cleavage of a spectrin-related protein by calcium-dependent protease in Neurospora crassa.

To investigate the functional significance of a cytoskeletal spectrin-like protein, we studied its localization pattern in Neurospora crassa and sought the answer to whether it is a substrate for another apically localized protein, the calcium-dependent protease (CDP II). Immunoblots of crude extracts from exponentially growing mycelia, separated by one- and two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis using antichicken alpha/beta-spectrin antibodies, revealed a single band of approximately relative mass (Mr) 100 kDa with an isoeletric point (pI) in the range of 6.5 to 7.

Effects of lindane on the photosynthetic apparatus of the cyanobacterium Anabaena: fluorescence induction studies and immunolocalization of ferredoxin-NADP+ reductase.

Intention, Goal, Scope, Background: Cyanobacteria have the natural ability to degrade moderate amounts of organic pollutants. However, when pollutant concentration exceeds the level of tolerance, bleaching of the cells and death occur within 24 hours. Under stress conditions, cyanobacterial response includes the short-term adaptation of the photosynthetic apparatus to light quality, named state transitions.

Spatial and cellular localization of calcium-dependent protease (CDP II) in Allomyces arbuscula.

Immunogold labeling of calcium-dependent neutral protease II (CDPII) with specific antibodies in near median longitudinal ultrathin sections of Allomyces arbuscula showed that the enzyme is predominantly localized in the growing hyphal and rhizoidal apices. The tips in both cell type had more enzyme than the distal regions and showed a gradient distribution. Labeling of the ultrathin sections and western blot analysis of purified subcellular fractions showed that CDPII is mainly cytosolic.

Swarming of Pseudomonas aeruginosa is dependent on cell-to-cell signaling and requires flagella and pili.

We describe swarming in Pseudomonas aeruginosa as a third mode of surface translocation in addition to the previously described swimming and twitching motilities. Swarming in P. aeruginosa is induced on semisolid surfaces (0.

Purification of a 47-kDa calmodulin-binding polypeptide as an actin-binding protein from Neurospora crassa.

We have enriched a 47-kDa polypeptide (p47) from Neurospora crassa on the basis of its affinity to calmodulin. The p47 was purified to homogeneity by chromatography on a Mono S cation exchange column and evidence is presented that the polypeptide co-sediments specifically with F-actin. The intracellular distribution of p47 and actin was also examined using indirect double immunofluorescence staining of cells at different stages of development.

Characterization of subpopulations of lipoprotein particles isolated from human cerebrospinal fluid.

The aim of the present study was to define lipoprotein complexes within cerebrospinal fluid (CSF) in terms of their apolipoprotein composition, using fractionation procedures considered optimal for maintaining lipoprotein structural integrity. Five apolipoproteins were identified, namely apolipoproteins A-I, A-IV, D, E and J. These were differentially distributed amongst lipoprotein particles of which three major subpopulations were identified.

A stringent role of F-actin in the ascogonial differentiation of Neurospora crassa fluffy mutant.

Cytochalasin D, an inhibitor of actin polymerization, interferes with ascogonial differentiation in the fertile fluffy mutant of Neurospora crassa. As the total level of actin and its mRNA remain unchanged, this suggests that it is in its microfilamentous form (F-form) that actin is stringently required for female differentiation.