Search results for "bacteri"

Modulation of Fatty Acid Patterns During Protoplast Isolation

1983

Protoplast isolation and regeneration is known from numerous plant species (Binding et al. 1). But there are plant species which show very unconstant regeneration or no reaction at all, even if the isolation showed high viability of the protoplasts. Does this lacking response only depend on medium composition and effectors or are there other unknown conditions? The procedure of protoplast isolation and the use of strong hypertonic media is a dramatic disturbance of cell metabolism and might be a stress situation, which cannot be overcome by the cell. Fleck et al. (2) reported “osmotic-stress proteins” in Nicotiana sylvestris protoplasts and Kaiser et al. (3) showed a remarkable influence of…

Biogas Cleaning by Hydrogen Sulfide Scrubbing and Bio-oxidation of Captured Sulfides

2015

Hydrogen sulfide and partially carbon dioxide can be absorbed into alkaline washing liquid with nitrates for upgrading a quality of biogas. Sulfides captured into the washing liquid are consequently biologically oxidized in an anoxic bioreactor by autotrophic denitrifying bacteria. Nitrates in the washing liquid serve as electron acceptors for sulfide bio-oxidation. Washing of hydrogen sulfide from biogas was examined in a lab-scale countercurrent scrubber that was packed with plastic carriers and operated at different biogas and washing liquid flows. The hydrogen sulfide concentration in treated biogas was investigated in the range from 3 to 12.3 g m–3. The influence of the hydrogen sulfid…

Identification of the 3-amino-3-carboxypropyl (acp) transferase enzyme responsible for acp3U formation at position 47 in Escherichia coli tRNAs

2019

AbstracttRNAs from all domains of life contain modified nucleotides. However, even for the experimentally most thoroughly characterized model organism Escherichia coli not all tRNA modification enzymes are known. In particular, no enzyme has been found yet for introducing the acp3U modification at position 47 in the variable loop of eight E. coli tRNAs. Here we identify the so far functionally uncharacterized YfiP protein as the SAM-dependent 3-amino-3-carboxypropyl transferase catalyzing this modification and thereby extend the list of known tRNA modification enzymes in E. coli. Similar to the Tsr3 enzymes that introduce acp modifications at U or m1Ψ nucleotides in rRNAs this protein conta…

2-Oxoglutarate decarboxylase ofLeuconostoc oenos

1990

InLeuconostoc oenos, the typical organism of the malolactic fermentation of wine, a 2-oxoglutarate decarboxylase was detected. This inducible enzyme decarboxylates 2-oxoglutarate but not pyruvate. The resulting succinaldehydate is rapidly reduced to 4-hydroxybutyrate or oxidized to succinate in further reactions. 2-Oxoglutarate decarboxylase is thiamin-diphosphate-dependent; the pH optimum is at 5.3 and theK m value for 2-oxoglutarate is 1.8 mmol/L.

Corrigendum to “Biomolecule-corona formation confers resistance of bacteria to nanoparticle-induced killing: Implications for the design of improved …

2020

A49 LACTOBACILLI DEGRADE WHEAT AMYLASE TRYPSIN INHIBITORS (ATI) TO AMELIORATE GUT DYSFUNCTION INDUCED BY IMMUNOGENIC WHEAT PROTEINS

2019

BACKGROUND: Wheat-related disorders involve a wide spectrum of conditions, triggered by the ingestion of gluten-containing cereals. The induction of gluten-specific immune responses in celiac disease is well established. However, the contribution of gluten and/or non-gluten proteins in the generation of symptoms in other wheat-related disorders is controversial. Amylase trypsin inhibitors (ATIs) are pest-resistant molecules in modern wheat with TLR4-activating capacities. AIMS: We investigated the role of ATIs in the generation of gut barrier dysfunction and dysmotility in wild-type mice as well as in the severity of gluten-induced immunopathology in genetically predisposed mice. We also de…

Lactobacillus vini sp. nov., a wine lactic acid bacterium homofermentative for pentoses.

2006

Six strains with more than 99·5 % 16S rRNA gene sequence similarity, identical internal spacer region profiles and restriction analysis of the amplified 16S rRNA gene patterns were isolated from fermenting grape musts during independent studies carried out in France and Spain many years apart. Strains are Gram-positive, motile, facultatively anaerobic rods that do not exhibit catalase activity and have the ability to utilize pentose sugars (ribose and/or l-arabinose), although they are homofermentative bacteria. Strains ferment pentoses exclusively yielding lactic acid as the end product. A broad set of molecular techniques has been applied to characterize these strains and the results show…

Novel Sortase A Inhibitors to Counteract Gram-Positive Bacterial Biofilms

2019

Sortase A (SrtA) is a membrane enzyme responsible for the covalent anchoring of surface proteins on the cell wall of Gram-positive bacteria. Nowadays it is considered an interesting target for the development of new anti-infective drugs which aim to interfere with important Gram-positive virulence mechanisms. Along the years, we studied the anti-staphylococcal and anti-biofilm activity of some natural and synthetic polyhalogenated pyrrolic compounds, called pyrrolomycins. Some of them were active on Gram-positive pathogens at a μg/mL range of concentration (1.5-0.045 μg/mL) and showed a biofilm inhibition in the range of 50-80%. [1-3] In light of these encouraging results, herein we present…

The dcuD (former yhcL ) gene product of Escherichia coli as a member of the DcuC family of C4-dicarboxylate carriers: lack of evident expression

1999

The dcuD gene (formerly yhcL) of Escherichia coli shows significant sequence similarity only to the dcuC gene of E. coli, which encodes a C4-dicarboxylate carrier (DcuC) that functions during anaerobic growth. Inactivation of dcuD had no effect on the growth of E. coli under a large number of conditions and led to no detectable changes in phenotype. Translational dcuD'-'lacZ gene fusions were not significantly expressed in the presence of dicarboxylates or monocarboxylates under oxic or anoxic conditions. Other potential substrates such as amino sugar derivatives, amino acids, and alpha-aspartyl dipeptides also did not lead to expression of dcuD. Changes in medium composition, pH, ionic str…

Inorganic Polyphosphate in Eukaryotes: Enzymes, Metabolism and Function

1999

Inorganic polyphosphates (polyP) are linear polymers of orthophosphate (Pi) residues linked by high-energy phosphoanhydride bonds. These polymers are widely distributed in nature, from archaebacteria, eubacteria, fungi, algae, and protozoa to higher plants and animals (for reviews, see Kulaev 1979; Wood and Clark 1988; Kornberg 1994, 1995). PolyP molecules are stable in neutral aqueous solutions, but are hydrolyzed by heat-treatment, and under acidic or alkaline conditions. The chain length of polyP may range from 3 to more than 1000 Pi residues; it can be analyzed on urea/polyacrylamide gels (Clark and Wood 1987; Lorenz et al. 1994a). In contrast to the linear polymer, branched inorganic p…