Search results for "Erich"

One-step synthesis, crystallographic studies and antimicrobial activity of new 4-diazopyrazole derivatives

1996

Summary A number of new 4-diazopyrazole derivatives were prepared by the reaction of 1- R -3-methyl-5(R 1 -substituted)benzamidopyrazoles with a sevenfold excess of nitrous acid in acetic medium. The compounds were tested for activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus faecalis, Listeria monocytogenes, Candida albicans, Candida tropicalis and Paecilomyces varioti . The highest microbial susceptibility was shown by Gram-positive bacteria, with minimum inhibitory concentrations (MIC) in the range 0.5–12.5 μg/mL. For S aureus the R 1 substituents were screened utilizing the Topliss operational scheme. The 4-nitro g…

TiO2 Supported over Hβ and HZSM-5 Photocatalysts for Salmonelle and Escherichia Coli Disinfection

2008

Functioning of DcuC as the C 4 -Dicarboxylate Carrier during Glucose Fermentation by Escherichia coli

1999

ABSTRACT The dcuC gene of Escherichia coli encodes an alternative C 4 -dicarboxylate carrier (DcuC) with low transport activity. The expression of dcuC was investigated. dcuC was expressed only under anaerobic conditions; nitrate and fumarate caused slight repression and stimulation of expression, respectively. Anaerobic induction depended mainly on the transcriptional regulator FNR. Fumarate stimulation was independent of the fumarate response regulator DcuR. The expression of dcuC was not significantly inhibited by glucose, assigning a role to DcuC during glucose fermentation. The inactivation of dcuC increased fumarate-succinate exchange and fumarate uptake by DcuA and DcuB, suggesting a…

Regulation of aerobic and anaerobic D-malate metabolism of Escherichia coli by the LysR-type regulator DmlR (YeaT).

2010

ABSTRACT Escherichia coli K-12 is able to grow under aerobic conditions on d -malate using DctA for d -malate uptake and the d -malate dehydrogenase DmlA (formerly YeaU) for converting d -malate to pyruvate. Induction of dmlA encoding DmlA required an intact dmlR (formerly yeaT ) gene, which encodes DmlR, a LysR-type transcriptional regulator. Induction of dmlA by DmlR required the presence of d -malate or l - or meso -tartrate, but only d -malate supported aerobic growth. The regulator of general C 4 -dicarboxylate metabolism (DcuS-DcuR two-component system) had some effect on dmlA expression. The anaerobic l -tartrate regulator TtdR or the oxygen sensors ArcB-ArcA and FNR did not have a m…

Thermostability of Two Cyanobacterial GrpE Thermosensors

2011

GrpE proteins act as co-chaperones for DnaK heat-shock proteins. The dimeric protein unfolds under heat stress conditions, which results in impaired interaction with a DnaK protein. Since interaction of GrpE with DnaK is crucial for the DnaK chaperone activity, GrpE proteins act as a thermosensor in bacteria. Here we have analyzed the thermostability and function of two GrpE homologs of the mesophilic cyanobacterium Synechocystis sp. PCC 6803 and of the thermophilic cyanobacterium Thermosynechococcus elongatus BP1. While in Synechocystis an N-terminal helix pair of the GrpE dimer appears to be the thermosensing domain and mainly mediates GrpE dimerization, the C-terminal four-helix bundle i…

Synthesis of recombinant atrial natriuretic peptide (rANP) using hybrid fusion protein-phage fr coat/ANP (CP/ANP).

1997

Abstract Baumanis, V., I. Jansone, A. Skangals, I. Mandrika and V. Berzins. Synthesis of recombinant atrial natriuretic peptide (rANP) using hybrid fusion protein-phage fr coat/ANP (CP/ANP). Peptides 18(8) 1229–1235, 1997.—Recombinant atrial natriuretic peptide (rANP) was expressed in and isolated from E. coli. rANP was purified using HPLC. Amino acid analysis, partial sequencing, and molecular mass were determined. Fused protein was used to rise polyclonal antibodies and to develop of immunoenzymatic assays of rANP and CP/ANP. Experiments were designed to study rANP effects on isolated rabbit aortic strips and to examine hypotensive, diuretic, and natriuretic activity, as well as renal cre…

Identification of the Weevil immune genes and their expression in the bacteriome tissue

2008

Abstract Background Persistent infections with mutualistic intracellular bacteria (endosymbionts) are well represented in insects and are considered to be a driving force in evolution. However, while pathogenic relationships have been well studied over the last decades very little is known about the recognition of the endosymbionts by the host immune system and the mechanism that limits their infection to the bacteria-bearing host tissue (the bacteriome). Results To study bacteriome immune specificity, we first identified immune-relevant genes of the weevil Sitophilus zeamais by using suppressive subtractive hybridization (SSH) and then analyzed their full-length coding sequences obtained b…

Identification of a plasminogen-binding motif in PAM, a bacterial surface protein.

1995

Surface-associated plasmin(ogen) may contribute to the invasive properties of various cells. Analysis of plasmin(ogen)-binding surface proteins is therefore of interest. The N-terminal variable regions of M-like (ML) proteins from five different group A streptococcal serotypes (33, 41, 52, 53 and 56) exhibiting the plasminogen-binding phenotype were cloned and expressed in Escherichia coli. The recombinant proteins all bound plasminogen with high affinity. The binding involved the kringle domains of plasminogen and was blocked by a lysine analogue, 6-aminohexanoic acid, indicating that lysine residues in the M-like proteins participate in the interaction. Sequence analysis revealed that the…

Self-reporting hydrogels rapidly differentiate among enterohemorrhagic Escherichia coli (EHEC) and non-virulent Escherichia coli (K12)

2016

Abstract We report on the development of an autonomously reporting indicator hydrogel for the rapid and selective detection of enzymes secreted by the food-borne biosafety level 3 pathogen enterohemorrhagic Escherichia coli (E. coli) O157:H7 (EHEC) and the differentiation of this pathogen from the non-virulent E. coli strain K12. To introduce the sensing functionality, chitosan hydrogel films were equipped with fluorogenic substrates for the detection of α-galactosidase (α-Gal) and β-galactosidase (β-Gal), which are secreted by E. coli O157:H7, and β-glucuronidase (β-GUS), which is produced by the non-virulent E. coli K12 strain, but not by E. coli O157:H7, respectively. In the presence of …

Straightforward Approach for Preparing Durable Antibacterial ZnO Nanoparticle Coatings on Flexible Substrates

2022

Flexible antibacterial materials have gained utmost importance in protection from the distribution of bacteria and viruses due to the exceptional variety of applications. Herein, we demonstrate a readily scalable and rapid single-step approach for producing durable ZnO nanoparticle antibacterial coating on flexible polymer substrates at room temperature. Substrates used are polystyrene, poly(ethylene-co-vinyl acetate) copolymer, poly(methyl methacrylate), polypropylene, high density polyethylene and a commercial acrylate type adhesive tape. The deposition was achieved by a spin-coating process using a slurry of ZnO nanoparticles in toluene. A stable modification layer was obtained when tolu…