scholarly journals Production of a Blue Pigment (Glaukothalin) by MarineRheinheimeraspp.

2009 ◽  
Vol 2009 ◽  
pp. 1-7 ◽  
Author(s):  
Hans-Peter Grossart ◽  
Marc Thorwest ◽  
Inken Plitzko ◽  
Thorsten Brinkhoff ◽  
Meinhard Simon ◽  
...  
Keyword(s):  
Wadden Sea ◽  
Pigment Production ◽  
Single Amino Acid ◽  
Blue Pigment ◽  
Molecular Formula ◽  
Blue Color ◽  
Bacterial Strains ◽  
Phylogenetic Groups ◽  
Deep Blue

Twoγ-Proteobacteriastrains, that is, HP1 and HP9, which both produce a diffusible deep blue pigment, were isolated from the German Wadden Sea and from the Øresund, Denmark, respectively. Both strains affiliate with the genusRheinheimera. Small amounts of the pigment could be extracted from HP1 grown in a 50 L fermenter and were purified chromatographically. Chemical analysis of the pigment including NMR and mass spectrometry led to a molecular formula ofC34H56N4O4(m.w. 584.85) which has not yet been reported in literature. The molecule is highly symmetrically and consists of two heterocyclic halves to which aliphatic side chains are attached. The pigment has been named glaukothalin due to its blue color and its marine origin (glaukos,gr.=blue,thalatta,gr.=sea). Production of glaukothalin on MB2216 agar plates by ourRheinheimerastrains is affected in the presence of other bacterial strains either increasing or decreasing pigment production. The addition of a single amino acid, arginine (5 gl−1), greatly increases pigment production by ourRheinheimerastrains. Even though the production of glaukothalin leads to inhibitory activity against three bacterial strains from marine particles, ourRheinheimeraisolates are inhibited by various bacteria of different phylogenetic groups. The ecological role of glaukothalin production byRheinheimerastrains, however, remains largely unknown.

scholarly journals New Blue Pigment Produced byPantoea agglomeransand Its Production Characteristics at Various Temperatures

2010 ◽  
Vol 77 (1) ◽  
pp. 172-178 ◽  
Author(s):  
Hiroshi Fujikawa ◽  
Ryo Akimoto
Keyword(s):  
Initial Density ◽  
Agar Plate ◽  
Water Soluble ◽  
Pigment Production ◽  
Blue Pigment ◽  
Bacterial Cells ◽  
Initial Cell ◽  
Low Temperature Storage ◽  
Deep Blue ◽  
Production Characteristics

ABSTRACTA bacterium capable of producing a deep blue pigment was isolated from the environment and identified asPantoea agglomerans. The pigment production characteristics of the bacterium under various conditions were studied. The optimal agar plate ingredients for pigment production by the bacterium were first studied: the optimal ingredients were 5 g/liter glucose, 10 g/liter tryptic soy broth, and 40 g/liter glycerol at pH 6.4. Bacterial cells grew on the agar plate during the incubation, while the pigment spread into the agar plate, meaning that it is water soluble. Pigment production was affected by the initial cell density. Namely, at higher initial cell densities ranging from 106.3to 108.2CFU/cm2on the agar plate, faster pigment production was observed, but no blue pigment was produced at a very high initial density of 109.1CFU/cm2. Thus, the cell population of 108.2CFU/cm2was used for subsequent study. Although the bacterium was capable of growing at temperatures above and below 10°C, it could produce the pigment only at temperatures of ≥10°C. Moreover, the pigment production was faster at higher temperatures in the range of 10 to 20°C. Pigment production at various temperature patterns was well described by a new logistic model. These results suggested that the bacterium could be used in the development of a microbial temperature indicator for the low-temperature-storage management of foods and clinical materials. To our knowledge, there is no otherP. agglomeransstrain capable of producing a blue pigment and the pigment is a new one of microbial origin.

10 THE ROLE OF DIETARY L-SERINE IN THE REGULATION OF INTESTINAL MUCUS BARRIER DURING INFLAMMATION

2020 ◽  
Vol 26 (Supplement_1) ◽  
pp. S42-S42
Author(s):  
Kohei Sugihara ◽  
Nobuhiko Kamada
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Gut Microbiota ◽  
Control Diet ◽  
Bacterial Strains ◽  
Germ Free ◽  
Intestinal Mucus ◽  
Gnotobiotic Mice ◽  
Mucus Barrier

Abstract Background Recent accumulating evidence suggests that amino acids have crucial roles in the maintenance of intestinal homeostasis. In inflammatory bowel disease (IBD), amino acid metabolism is changed in both host and the gut microbiota. Among amino acids, L-serine plays a central role in several metabolic processes that are essential for the growth and survival of both mammalian and bacterial cells. However, the role of L-serine in intestinal homeostasis and IBD remains incompletely understood. In this study, we investigated the effect of dietary L-serine on intestinal inflammation in a murine model of colitis. Methods Specific pathogen-free (SPF) mice were fed either a control diet (amino acid-based diet) or an L-serine-deficient diet (SDD). Colitis was induced by the treatment of dextran sodium sulfate (DSS). The gut microbiome was analyzed by 16S rRNA sequencing. We also evaluate the effect of dietary L-serine in germ-free mice and gnotobiotic mice that were colonized by a consortium of non-mucolytic bacterial strains or the consortium plus mucolytic bacterial strains. Results We found that the SDD exacerbated experimental colitis in SPF mice. However, the severity of colitis in SDD-fed mice was comparable to control diet-fed mice in germ-free condition, suggesting that the gut microbiota is required for exacerbation of colitis caused by the restriction of dietary L-serine. The gut microbiome analysis revealed that dietary L-serine restriction fosters the blooms of a mucus-degrading bacterium Akkermansia muciniphila and adherent-invasive Escherichia coli in the inflamed gut. Consistent with the expansion of mucolytic bacteria, SDD-fed mice showed a loss of the intestinal mucus layer. Dysfunction of the mucus barrier resulted in increased intestinal permeability, thereby leading to bacterial translocation to the intestinal mucosa, which subsequently increased the severity of colitis. The increased intestinal permeability and subsequent bacterial translocation were observed in SDD-fed gnotobiotic mice that colonized by mucolytic bacteria. In contrast, dietary L-serine restriction did not alter intestinal barrier integrity in gnotobiotic mice that colonized only by non-mucolytic bacteria. Conclusion Our results suggest that dietary L-serine regulates the integrity of the intestinal mucus barrier during inflammation by limiting the expansion of mucus degrading bacteria.

The Only Function of Grauzone Required for Drosophila Oocyte Meiosis Is Transcriptional Activation of the cortex Gene

Genetics ◽  
2000 ◽  
Vol 155 (4) ◽  
pp. 1831-1839
Author(s):  
Emily Harms ◽  
Tehyen Chu ◽  
Gwénola Henrion ◽  
Sidney Strickland
Keyword(s):  
Zinc Finger ◽  
Transcriptional Activation ◽  
Single Amino Acid ◽  
Primary Role ◽  
Extra Copy ◽  
Oocyte Meiosis ◽  
Zinc Finger Motifs ◽  
High Level ◽  
Transcriptional Pathway

Abstract The grauzone and cortex genes are required for the completion of meiosis in Drosophila oocytes. The grauzone gene encodes a C2H2-type zinc-finger transcription factor that binds to the cortex promoter and is necessary for high-level activation of cortex transcription. Here we define the region of the cortex promoter to which Grauzone binds and show that the binding occurs through the C-terminal, zinc-finger-rich region of the protein. Mutations in two out of the five grauzone alleles result in single amino acid changes within different zinc-finger motifs. Both of these mutations result in the inability of Grauzone to bind DNA effectively. To determine the mechanism by which Grauzone regulates meiosis, transgenic flies were produced with an extra copy of the cortex gene in homozygous grauzone females. This transgene rescued the meiosis arrest of embryos from these mutants and allowed their complete development, indicating that activation of cortex transcription is the primary role of Grauzone during Drosophila oogenesis. These experiments further define a new transcriptional pathway that controls the meiotic cell cycle in Drosophila oocytes.

Unraveling the Important Role of High‐Lying Triplet–Lowest Excited Singlet Transitions in Achieving Highly Efficient Deep‐Blue AIE‐Based OLEDs

2021 ◽  
Vol 33 (11) ◽  
pp. 2006953
Author(s):  
Xiaomin Guo ◽  
Peisen Yuan ◽  
Jianzhong Fan ◽  
Xianfeng Qiao ◽  
Dezhi Yang ◽  
...  
Keyword(s):  
Excited Singlet ◽  
Highly Efficient ◽  
Deep Blue

scholarly journals Role of the Ser-287-Asn Replacement in the Hydrolysis Spectrum Extension of AmpC β-Lactamases in Escherichia coli

2008 ◽  
Vol 53 (1) ◽  
pp. 323-326 ◽  
Author(s):  
Hedi Mammeri ◽  
Moreno Galleni ◽  
Patrice Nordmann
Keyword(s):  
Escherichia Coli ◽  
Biochemical Characterization ◽  
Catalytic Efficiency ◽  
Phylogenetic Groups ◽  
Extended Spectrum ◽  
Group A

ABSTRACT Two AmpC variants harboring the S287N substitution were obtained by mutagenesis from cephalosporinases representative of the phylogenetic groups A and B2 of Escherichia coli. Their biochemical characterization revealed that the S287N replacement led to an important increase in the catalytic efficiency toward extended-spectrum cephalosporins in the AmpC β-lactamase of group A only.

scholarly journals Pyrrolnitrin Biosynthesis From Rhizospheric Serratia Spp. With Antifungal Activity and Binding Interactions of PrnF With Ligands

2020 ◽  
Author(s):  
Shraddha P. Pawar ◽  
Ambalal B. Chaudhari
Keyword(s):  
Antifungal Activity ◽  
Phytopathogenic Fungi ◽  
Bacterial Strains ◽  
Rrna Sequence ◽  
16S Rrna Sequence ◽  
Protein Model ◽  
Stenotrophomonas Rhizophila ◽  
K 12 ◽  
Layer Chromatography

Abstract Pyrrolnitrin (PRN) from rhizobacteria displays a key role in biocontrol of phytopathogenic fungi in rhizospheric soil. Therefore, different rhizospheric soils were investigated for the prevalence of PRN producer in minimal salt (MS) medium containing tryptophan (0.2 M NaCl; pH 8) using three successive enrichments. Of 12% isolates, only five bacterial strains had shown PRN secretion, screened with Thin Layer Chromatography (Rf 0.8) and antifungal activity (27 mm) against phytopathogen. The phenetic and 16S rRNA sequence revealed the close affiliation of isolates (KMB, M-2, M-11, TW3, and TO2) to Stenotrophomonas rhizophila (KY800458), Enterobacter spp. (KY800455), Brevibacillus parabrevis (KY800454), Serratia marcescens (KY800456) and Serratia nemtodiphila (KY800457). Purified compound from isolates was characterised using UV, IR, HPLC, LCMS and GCMS as PRN. However, BLASTn hit of prn gene sequences from both Serratia species showed 99% similarity with NADPH dependent FMN reductase component (prnF). The homology protein model of prnF was developed from translated sequence of S. marcescens TW3 with chromate reductase of Escherichia coli K-12. Docking with FMN and NADPH was performed. The study demonstrated the possible role of prnF NADPH dependent FMN reductases in prnD for supply of reduced flavin in rhizobacterial strain of Serratia spp. which may pave a way to understand PRN production.

scholarly journals Towards Blue AIE/AIEE: Synthesis and Applications in OLEDs of Tetra-/Triphenylethenyl Substituted 9,9-Dimethylacridine Derivatives

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 445 ◽  
Author(s):  
Monika Cekaviciute ◽  
Aina Petrauskaite ◽  
Sohrab Nasiri ◽  
Jurate Simokaitiene ◽  
Dmytro Volyniuk ◽  
...  
Keyword(s):  
Solid State ◽  
Quantum Yields ◽  
Yellow Emission ◽  
Blue Color ◽  
Television System ◽  
Fluorescence Quantum Yields ◽  
Deep Blue ◽  
Wide Range ◽  
Cyano Groups ◽  
High Yields

Aiming to design blue fluorescent emitters with high photoluminescence quantum yields in solid-state, nitrogen-containing heteroaromatic 9,9-dimethylacridine was refined by tetraphenylethene and triphenylethene. Six tetra-/triphenylethene-substituted 9,9-dimethylacridines were synthesized by the Buchwald-Hartwig method with relatively high yields. Showing effects of substitution patterns, all emitters demonstrated high fluorescence quantum yields of 26–53% in non-doped films and 52–88% in doped films due to the aggregation induced/enhanced emission (AIE/AIEE) phenomena. In solid-state, the emitters emitted blue (451–481 nm) without doping and deep-blue (438–445 nm) with doping while greenish-yellow emission was detected for two compounds with additionally attached cyano-groups. The ionization potentials of the derivatives were found to be in the relatively wide range of 5.43–5.81 eV since cyano-groups were used in their design. Possible applications of the emitters were demonstrated in non-doped and doped organic light-emitting diodes with up to 2.3 % external quantum efficiencies for simple fluorescent devices. In the best case, deep-blue electroluminescence with chromaticity coordinates of (0.16, 0.10) was close to blue color standard (0.14, 0.08) of the National Television System Committee.

scholarly journals The Role of Fusobacterium nucleatum in Colorectal Carcinogenesis

Pathobiology ◽  
2020 ◽  
pp. 1-14
Author(s):  
José Guilherme Datorre ◽  
Ana Carolina de Carvalho ◽  
Denise Peixoto Guimarães ◽  
Rui Manuel Reis
Keyword(s):  
Clinical Utility ◽  
Therapy Response ◽  
Fusobacterium Nucleatum ◽  
Colorectal Carcinogenesis ◽  
Intestinal Microbiome ◽  
Bacterial Strains ◽  
Molecular Features ◽  
Important Target ◽  
Intestinal Dysbiosis

Colorectal cancer (CRC) is one of the most frequent and deadly neoplasms worldwide. Genetic factors, lifestyle habits, and inflammation are important risk factors associated with CRC development. In recent years, growing evidence has supporting the significant role of the intestinal microbiome in CRC carcinogenesis. Disturbances in the healthy microbial balance, known as dysbiosis, are frequently observed in these patients. Pathogenic microorganisms that induce intestinal dysbiosis have become an important target to determine the role of bacterial infection in tumorigenesis. Interestingly, the presence of different bacterial strains, such as <i>Fusobacterium nucleatum</i>, has been detected in tissue and stool from patients with CRC and associated with substantial clinical and molecular features, as well as with patient therapy response. Therefore, understanding how the presence and levels of <i>F. nucleatum</i>strains in the gut affect the risk of CRC onset and progression may inform suitable candidates for interventions focused on modulation of this bacteria. Here we review new insights into the role of gut microbiota in CRC carcinogenesis and the clinical utility of using the detection of <i>F. nucleatum</i> in different settings such as screening, prognosis, and microbiota modulation as a means to prevent cancer, augment therapies, and reduce adverse effects of treatment.

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