scholarly journals Isolation and Characterization of a Novel Antialgal Allelochemical from Phragmites communis

2005 ◽  
Vol 71 (11) ◽  
pp. 6545-6553 ◽  
Author(s):  
Feng-Min Li ◽  
Hong-Ying Hu
Keyword(s):  
Metal Ion ◽  
Membrane Integrity ◽  
Chlorella Pyrenoidosa ◽  
Gas Chromatography Mass Spectrometry ◽  
Ion Leakage ◽  
Phragmites Communis ◽  
Allelopathic Activity ◽  
Isolation And Characterization ◽  
Species Specific

ABSTRACT Antialgal allelochemicals were isolated from Phragmites communis Tris. The isolated allelopathic fraction showed strong inhibition activity on the growth of Chlorella pyrenoidosa and Microcystis aeruginosa but had no inhibition on Chlorella vulgaris. The 50% effective concentrations (EC50) of the allelopathic fractions on C. pyrenoidosa and M. aeruginosa were 0.49 and 0.79 mg/liter, respectively. The allelopathic activity of the fraction was species-specific. The isolated allelopathic fraction caused metal ion leakage from algal cells. The fraction decreased the activities of antioxidant enzymes, such as superoxide dismutase and peroxidase. The addition of the isolated fraction increased the concentration of unsaturated lipid fatty acids in cell membrane of C. pyrenoidosa and M. aeruginosa. This caused a change in plasma membrane integrity and the leakage of ions in the protoplast. The allelopathic compound was identified by nuclear magnetic resonance and gas chromatography-mass spectrometry as ethyl 2-methylacetoacetate. Synthesized ethyl 2-methylacetoacetate also showed allelopathic activity on C. pyrenoidosa and M. aeruginosa. The EC50 of synthesized ethyl 2-methylacetoacetate on C. pyrenoidosa and M. aeruginosa were 0.49 and 0.65 mg/liter, respectively.

scholarly journals Isolation and Characterization of 4-tert-Butylphenol-Utilizing Sphingobium fuliginis Strains from Phragmites australis Rhizosphere Sediment

2010 ◽  
Vol 76 (20) ◽  
pp. 6733-6740 ◽  
Author(s):  
Tadashi Toyama ◽  
Naonori Momotani ◽  
Yuka Ogata ◽  
Yuji Miyamori ◽  
Daisuke Inoue ◽  
...  
Keyword(s):  
Cell Growth ◽  
Phragmites Australis ◽  
Gas Chromatography Mass Spectrometry ◽  
Side Chains ◽  
Isolation And Characterization ◽  
Alkyl Side Chains ◽  
Basal Salts ◽  
Growth Experiments ◽  
Rhizosphere Sediment

ABSTRACT We isolated three Sphingobium fuliginis strains from Phragmites australis rhizosphere sediment that were capable of utilizing 4-tert-butylphenol as a sole carbon and energy source. These strains are the first 4-tert-butylphenol-utilizing bacteria. The strain designated TIK-1 completely degraded 1.0 mM 4-tert-butylphenol in basal salts medium within 12 h, with concomitant cell growth. We identified 4-tert-butylcatechol and 3,3-dimethyl-2-butanone as internal metabolites by gas chromatography-mass spectrometry. When 3-fluorocatechol was used as an inactivator of meta-cleavage enzymes, strain TIK-1 could not degrade 4-tert-butylcatechol and 3,3-dimethyl-2-butanone was not detected. We concluded that metabolism of 4-tert-butylphenol by strain TIK-1 is initiated by hydroxylation to 4-tert-butylcatechol, followed by a meta-cleavage pathway. Growth experiments with 20 other alkylphenols showed that 4-isopropylphenol, 4-sec-butylphenol, and 4-tert-pentylphenol, which have alkyl side chains of three to five carbon atoms with α-quaternary or α-tertiary carbons, supported cell growth but that 4-n-alkylphenols, 4-tert-octylphenol, technical nonylphenol, 2-alkylphenols, and 3-alkylphenols did not. The rate of growth on 4-tert-butylphenol was much higher than that of growth on the other alkylphenols. Degradation experiments with various alkylphenols showed that strain TIK-1 cells grown on 4-tert-butylphenol could degrade 4-alkylphenols with variously sized and branched side chains (ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-heptyl, n-octyl, tert-octyl, n-nonyl, and branched nonyl) via a meta-cleavage pathway but not 2- or 3-alkylphenols. Along with the degradation of these alkylphenols, we detected methyl alkyl ketones that retained the structure of the original alkyl side chains. Strain TIK-1 may be useful in the bioremediation of environments polluted by 4-tert-butylphenol and various other 4-alkylphenols.

scholarly journals Isolation and Characterization of a Novel Single-Stranded RNA Virus Infecting the Bloom-Forming Diatom Rhizosolenia setigera

2004 ◽  
Vol 70 (2) ◽  
pp. 704-711 ◽  
Author(s):  
Keizo Nagasaki ◽  
Yuji Tomaru ◽  
Noriaki Katanozaka ◽  
Yoko Shirai ◽  
Kensho Nishida ◽  
...  
Keyword(s):  
Host Specificity ◽  
Rna Virus ◽  
Biological Properties ◽  
Rna Molecules ◽  
Isolation And Characterization ◽  
Ssrna Virus ◽  
Ecological Relationship ◽  
Rhizosolenia Setigera ◽  
Species Specific

ABSTRACT A novel single-stranded RNA (ssRNA) virus specifically infecting the bloom-forming diatom Rhizosolenia setigera (R. setigera RNA virus [RsRNAV]) was isolated from Ariake Sea, Japan. Viral replication occurred within the cytoplasm, and the virus particle was icosahedral, lacked a tail, and was 32 nm in diameter on average. The major nucleic acid extracted from the RsRNAV particles was an ssRNA molecule 11.2 kb in length, although smaller RNA molecules (0.6, 1.2, and 1.5 kb) were occasionally observed. The major structural proteins of RsRNAV were 41.5, 41.0, and 29.5 kDa. Inter- and intraspecies host specificity tests revealed that RsRNAV is not only species specific but also strain specific and that its intraspecies host specificity is diverse among virus clones. The latent period of RsRNAV was 2 days, and the burst sizes were 3,100 and 1,010 viruses per host cell when viruses were inoculated into the host culture at the exponential and stationary growth phases, respectively, at 15°C under a 12-h-12-h light-dark cycle of ca. 110 μmol of photons m−2 s−1 with cool white fluorescent illumination. To our knowledge, this is the first report describing the biological properties of a virus infecting a diatom. Further studies on RsRNAV will be helpful in understanding the ecological relationship between diatoms and viruses in nature.

scholarly journals Isolation and Characterization of Brachyspira spp. from Dogs in the Czech Republic

2010 ◽  
Vol 79 (3) ◽  
pp. 437-442
Author(s):  
Daniel Šperling ◽  
František Čada ◽  
Alois Čížek
Keyword(s):  
Czech Republic ◽  
Biochemical Activity ◽  
Animal Shelters ◽  
The Czech Republic ◽  
Specific Pcr ◽  
Isolation And Characterization ◽  
High Prevalence ◽  
Species Specific

The objectives of this study were to establish the prevalence of intestinal Spirochetes of the genusBrachyspirain Czech dogs and to determine the susceptibility of obtainedB. pilosicoliisolates to selected antibacterial substances. Spirochetes were diagnosed microscopically in 23 out of 1139 samples of dogs’ excrements, primarily intended for a parasitological testing. The cultivation of positive samples provided 10 brachyspira isolates, which were, on the basis of their biochemical activity and the results of the species-specific PCR, identified asB. pilosicoli(9 isolates) andB. hyodysenteriae(1 isolate). These dogs came from households. All the 7 tested isolatesB. pilosicoliwere sensitive to metronidazole and doxycycline, uniformly resistant to erythromycin, partly sensitive to cefazoline, lincomicine and ampicilline except for one isolate ofB. pilosicoli, which was resistant to ampicilline. The second part of study was focused on dogs with diarrhoea that came from animal shelters, where a high prevalence of 58% (10/17) ofB. pilosicoliwas found.

scholarly journals Construction of soil defined media using quantitative exometabolomic analysis of soil metabolites

2017 ◽  
Author(s):  
Stefan Jenkins ◽  
Tami L Swenson ◽  
Rebecca Lau ◽  
Andrea Rocha ◽  
Alex Aaring ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Molecular Weight ◽  
Organic Carbon ◽  
Quantitative Information ◽  
Water Soluble ◽  
Gas Chromatography Mass Spectrometry ◽  
Isolation And Characterization ◽  
Defined Media ◽  
Chromatography Mass Spectrometry

Exometabolomics enables analysis of metabolite utilization of low molecular weight organic substances by soil isolates. Environmentally-based defined media are needed to examine ecologically relevant patterns of substrate utilization. Here, we describe an approach for the construction of defined media using untargeted characterization of water soluble soil metabolites. To broadly characterize soil metabolites, both liquid chromatography mass spectrometry (LC/MS) and gas chromatography mass spectrometry (GC/MS) were used. With this approach, 96 metabolites were identified, including amino acids, amino acid derivatives, sugars, sugar alcohols, mono- and di-carboxylic acids, osmolytes, nucleobases, and nucleosides. From this pool of metabolites, 25 were quantified. Water soluble organic carbon was fractionated by molecular weight and measured to determine the fraction of carbon accounted for by the quantified metabolites. This revealed that, much like soil microbial community structures, these soil metabolites have an uneven quantitative distribution, with a single metabolite, trehalose accounting for 9.9 percent of the (< 1 kDa) water extractable organic carbon. This quantitative information was used to formulate two soil defined media (SDM), one containing 23 metabolites (SDM1) and one containing 46 (SDM2). To evaluate SDM for supporting the growth of bacteria found at this field site, we examined the growth of 30 phylogenetically diverse soil isolates obtained using standard R2A medium. The simpler SDM1 supported the growth of up to 13 isolates while the more complex SDM2 supported up to 25 isolates. One isolate, Pseudomonas corrugata strain FW300-N2E2 was selected for a time-series exometabolomics analysis to investigate SDM1 substrate preferences. Interestingly, it was found that this organism preferred lower-abundance substrates such as guanine, glycine, proline and arginine and glucose and did not utilize the more abundant substrates maltose, mannitol, trehalose and uridine. These results demonstrate the viability and utility of using exometabolomics to construct a tractable environmentally relevant media. We anticipate that this approach can be expanded to other environments to enhance isolation and characterization of diverse microbial communities.

Isolation and characterization of species-specific microsatellite markers for blue and black wildebeest (Connochaetes taurinus and C. gnou)

2018 ◽  
Vol 97 (S1) ◽  
pp. 101-109 ◽  
Author(s):  
Anna M. Van Wyk ◽  
Antoinette Kotzé ◽  
J. Paul Grobler ◽  
Bettine Janse Van Vuuren ◽  
Lisa N. Barrow ◽  
...  
Keyword(s):  
Microsatellite Markers ◽  
Isolation And Characterization ◽  
Black Wildebeest ◽  
Species Specific ◽  
Connochaetes Taurinus

scholarly journals Characterization of a Highly Thermostable Alkaline Phosphatase from the Euryarchaeon Pyrococcus abyssi

2001 ◽  
Vol 67 (10) ◽  
pp. 4504-4511 ◽  
Author(s):  
Sébastien Zappa ◽  
Jean-Luc Rolland ◽  
Didier Flament ◽  
Yannick Gueguen ◽  
Joseph Boudrant ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Disulfide Bonds ◽  
Metal Ion ◽  
Divalent Cations ◽  
E Coli ◽  
Isolation And Characterization ◽  
Pyrococcus Abyssi ◽  
Increased Activity ◽  
Metal Ion Chelators

ABSTRACT This work reports the first isolation and characterization of an alkaline phosphatase (AP) from a hyperthermophilic archaeon. An AP gene from Pyrococcus abyssi, a euryarchaeon isolated from a deep-sea hydrothermal vent, was cloned and the enzyme expressed in Escherichia coli. Analysis of the sequence showed conservation of the active site and structural elements of theE. coli AP. The recombinant AP was purified and characterized. Monomeric and homodimeric active forms were detected, with a monomer molecular mass of 54 kDa. Apparent optimum pH and temperature were estimated at 11.0 and 70°C, respectively. Thus far,P. abyssi AP has been demonstrated to be the most thermostable AP, with half-lives at 100 and 105°C of 18 and 5 h, respectively. Enzyme activity was found to be dependent on divalent cations: metal ion chelators inhibited activity, whereas the addition of exogenous Mg(II), Zn(II), and Co(II) increased activity. The enzyme was inhibited by inorganic phosphate, but not by molybdate and vanadate. Strong inhibitory effects were observed in the presence of thiol-reducing agents, although cysteine residues of the P. abyssi AP were not found to be incorporated within intra- or interchain disulfide bonds. In addition,P. abyssi AP was demonstrated to dephosphorylate linear DNA fragments with dephosphorylation efficiencies of 93.8 and 84.1% with regard to cohesive and blunt ends, respectively.

Preparation, isolation, and characterization of permethylated galactosides and fucosides

1999 ◽  
Vol 77 (3) ◽  
pp. 319-325 ◽  
Author(s):  
Daniel D Asres ◽  
Hélène Perreault
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Gas Chromatography ◽  
Gas Chromatography Mass Spectrometry ◽  
Characterization Methods ◽  
Isolation And Characterization ◽  
Nmr Data ◽  
Layer Chromatography ◽  
Structural Aspects

Sugar analysis involving permethylation followed by methanolysis can lead to significant results, given that permethylated monosaccharide standards are available for comparison of spectral and chromatographic data. Such standards are not readily commercially available, especially the furanoside forms. This note describes the isolation and characterization of permethylated pyranoside and furanoside species of D(+)-galactose and L(-)-fucose. Separation of the isomers was optimized using a combination of column chromatography and continuous elution thin-layer chromatography (TLC). TLC, gas chromatography - mass spectrometry, and 1H nuclear magnetic resonance (NMR) spectroscopy were used as the characterization methods. The isolation of furanosides is emphasized, since no specific NMR data have been reported on those to date, while several reports have already discussed the structural aspects of pyranosides.Key words: permethylation, monosaccharide, GC-MS, TLC, NMR.

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