scholarly journals Poly-3-Hydroxybutyrate in Legionella pneumophila, an Energy Source for Survival in Low-Nutrient Environments

1999 ◽  
Vol 65 (2) ◽  
pp. 822-827 ◽  
Author(s):  
Brian W. James ◽  
W. Stuart Mauchline ◽  
P. Julian Dennis ◽  
C. William Keevil ◽  
Robin Wait
Keyword(s):  
Legionella Pneumophila ◽  
Tap Water ◽  
Water Environment ◽  
Nile Red ◽  
Dry Weight ◽  
Gas Chromatography Mass Spectrometry ◽  
Resonance Spectroscopy ◽  
Term Survival ◽  
Reliable Determination ◽  
Nonculturable Cells

ABSTRACT Chloroform-soluble material was extracted from two strains ofL. pneumophila serogroup 1 following growth in continuous culture. The purified material was identified as poly-3-hydroxybutyrate (PHB) by nuclear magnetic resonance spectroscopy and by gas chromatography-mass spectrometry. PHB yields of up to 16% of cell dry weight were extracted from culture samples. The PHB was located in electron-dense intracellular inclusions, which fluoresced bright yellow when stained with the lipophilic dye Nile red. A Nile red spectrofluorometric assay provided a more accurate and reliable determination of the PHB content. PHB accumulation increased threefold during iron-limited culture and was inversely related to the concentration of iron metabolized. Chemostat-grown cells survived in a culturable state for at least 600 days when incubated at 24°C in a low-nutrient tap water environment. Nile red spectrofluorometry and flow cytometry demonstrated that PHB reserves were utilized during starvation. PHB utilization, as revealed by the decline in mean cellular fluorescence and cell complexity, correlated with loss of culturability. Fluorescence microscopy provided visual evidence of PHB utilization, with a marked reduction in the number of Nile red-stained granules during starvation. Heat shock treatment failed to resuscitate nonculturable cells. This study demonstrates that L. pneumophila accumulates significant intracellular reserves of PHB, which promote its long-term survival under conditions of starvation.

scholarly journals csrR, a Paralog and Direct Target of CsrA, Promotes Legionella pneumophila Resilience in Water

mBio ◽  
2015 ◽  
Vol 6 (3) ◽  
Author(s):  
Zachary D. Abbott ◽  
Helen Yakhnin ◽  
Paul Babitzke ◽  
Michele S. Swanson
Keyword(s):  
Legionella Pneumophila ◽  
Tap Water ◽  
Bacterial Species ◽  
Regulatory Protein ◽  
Opportunistic Pathogen ◽  
Water Systems ◽  
Phenotypic Analysis ◽  
Term Survival ◽  
Content Type

ABSTRACTCritical to microbial versatility is the capacity to express the cohort of genes that increase fitness in different environments.Legionella pneumophilaoccupies extensive ecological space that includes diverse protists, pond water, engineered water systems, and mammalian lung macrophages. One mechanism that equips this opportunistic pathogen to adapt to fluctuating conditions is a switch between replicative and transmissive cell types that is controlled by the broadly conserved regulatory protein CsrA. A striking feature of the legionellae surveyed is that each of 14 strains encodes 4 to 7csrA-like genes, candidate regulators of distinct fitness traits. Here we focus on the onecsrAparalog (lpg1593) that, like the canonicalcsrA, is conserved in all 14 strains surveyed. Phenotypic analysis revealed that long-term survival in tap water is promoted by thelpg1593locus, which we namecsrR(for “CsrA-similar protein forresilience”). As predicted by its GGA motif,csrRmRNA was bound directly by the canonical CsrA protein, as judged by electromobility shift and RNA-footprinting assays. Furthermore, CsrA repressed translation ofcsrRmRNAin vivo, as determined by analysis ofcsrR-gfpreporters,csrRmRNA stability in the presence and absence ofcsrAexpression, and mutation of the CsrA binding site identified on thecsrRmRNA. Thus, CsrA not only governs the transition from replication to transmission but also represses translation of its paralogcsrRwhen nutrients are available. We propose that, during prolonged starvation, relief of CsrA repression permits CsrR protein to coordinateL. pneumophila's switch to a cell type that is resilient in water supplies.IMPORTANCEPersistence ofL. pneumophilain water systems is a public health risk, and yet there is little understanding of the genetic determinants that equip this opportunistic pathogen to adapt to and survive in natural or engineered water systems. A potent regulator of this pathogen's intracellular life cycle is CsrA, a protein widely distributed among bacterial species that is understood quite well. Our finding that every sequencedL. pneumophilastrain carries severalcsrAparalogs—including two common to all isolates—indicates that the legionellae exploit CsrA regulatory switches for multiple purposes. Our discovery that one paralog, CsrR, is a target of CsrA that enhances survival in water is an important step toward understanding colonization of the engineered environment by pathogenicL. pneumophila.

Long-term survival of human rotavirus in raw and treated river water

1985 ◽  
Vol 31 (2) ◽  
pp. 124-128 ◽  
Author(s):  
Roderick A. Raphael ◽  
Syed A. Sattar ◽  
V. Susan Springthorpe
Keyword(s):  
River Water ◽  
Water Samples ◽  
Tap Water ◽  
Water Environment ◽  
Virus Titre ◽  
Virus Infectivity ◽  
Raw Water ◽  
Significant Drop ◽  
Term Survival ◽  
Human Rotavirus

This study was aimed at assessing the role of water as a vehicle for rotavirus spread by determining how well these viruses survive in the water environment. A cell culture adapted strain of human rotavirus subgroup 2, grown in MA-104 cells, was used as a model. Virus survival was tested in the following types of water samples, derived from the Ottawa River, at two different times of the year: (i) raw water (RW), (ii) municipally treated tap water (TW), and (iii) raw water that had been filtered (FW) through a membrane (0.22 μm). The water samples, with approximately 5.0 × 104 plaque-forming units (PFU) of the virus, were held at either 4 or 20 °C and tested for infectious virus over a period of 64 days. The TW samples had a total and free chlorine content of 0.05 and <0.05 mg/L, respectively. The chlorine in these samples was not neutralized before virus contamination. Irrespective of the holding temperature, the virus titre in FW remained essentially unaltered throughout the test period. In TW held at 4 °C, there was no significant drop in the virus titre even after 64 days, whereas at 20 °C the titre in TW was reduced by about 2 log10 over the same period. Even though the loss of virus infectivity was most rapid in RW held at 20 °C, it took about 10 days for a 99.0% reduction in the plaque titre of the virus. These findings, therefore, indicate that rotaviruses can survive for several days in raw and treated river water thus making recreational and potable waters potential vehicles for the transmission of rotavirus infections.

Identification of new lignans in Norway spruce knotwood extracts

Holzforschung ◽  
2012 ◽  
Vol 66 (5) ◽  
pp. 553-567 ◽  
Author(s):  
Annika I. Smeds ◽  
Iveta Češková ◽  
Patrik C. Eklund ◽  
Stefan M. Willför
Keyword(s):  
Mass Spectrometry ◽  
Norway Spruce ◽  
High Performance ◽  
Mass Spectra ◽  
Ethanol Extract ◽  
Dry Weight ◽  
Flash Chromatography ◽  
Gas Chromatography Mass Spectrometry ◽  
Resonance Spectroscopy ◽  
Hydrophilic Extract

Abstract In a hydrophilic extract of Norway spruce knotwood, the dominating lignan, 7-hydroxymatairesinol, was partially removed by precipitation, and the resulting mixture was fractionated by flash chromatography and preparative high-performance liquid chromatography (HPLC). In the HPLC fractions, 7S- and 7R-todolactol A, 7′-hydroxylariciresinol, and two stereoisomers of 9′-hydroxylariciresinol were identified by gas chromatography-mass spectrometry (GC-MS) analyses, and their structures were confirmed by nuclear magnetic resonance spectroscopy. The 9′-hydroxylariciresinols were suggested to have the 7S,8R,8′R,9′Rand 7R,8R,8′R,9′Rconfigurations, and (-)-7′-hydroxylariciresinol 7S*,7′R*,8R*,8′S*, which indicates a configuration of this structure that has not been reported previously. 7S- and 7R-isoliovil were identified by comparison with previously published GC-MS data, and 7′-oxolariciresinol was tentatively identified on the basis of its mass spectrum. Of these lignans, only 7′-hydroxylariciresinol has been identified previously in Norway spruce. Several other lignans with similar mass spectra as the todolactols, isoliovils, and 7′-hydroxylariciresinol were detected, indicating that they are different stereoisomers of these lignans and/or of liovils. In addition to these lignans, the mass spectra of several other unidentified minor lignans indicated the presence of several tens of previously unidentified minor lignans in Norway spruce knotwood, accounting altogether for approximately 6% of the dry weight of the ethanol extract. 7S-Todolactol A, which was dominating among the new lignans, was found to be very unstable in aqueous solutions. Identification of more of these unidentified lignans may be possible only by access to pure reference compounds.

scholarly journals Effect of Salinity Levels (NaCl) on Yield, Yield Components and Quality Content of Sesame (Sesamum Indicum L.) Cultivars

2016 ◽  
Vol 5 (2) ◽  
pp. 104
Author(s):  
Helale Bahrami ◽  
Amir Ostadi Jafari ◽  
Jamshid Razmjoo
Keyword(s):  
Plant Height ◽  
Yield Components ◽  
Seed Oil ◽  
Tap Water ◽  
Dry Weight ◽  
Salinity Level ◽  
Shoot Dry Weight ◽  
Weight Yield ◽  
Yield And Yield Components ◽  
Salinity Levels

<p class="emsd-body"><span lang="EN-GB">Seeds of ten sesame cultivars (Karaj, Darab, Safiabad, Jiroft, Borazjan, Yellow-white, Felestin, Ultan, Isfahan and Abpakhsh) were sown into soil filled pots in 2008 and 2009. Pots were watered with six levels of salts (0.0038 (tap water as control), 4.89, 8.61, 10.5, 14.54, 17.74 ds.m<sup>-1</sup> NaCl) until full maturity. Plant height, root and shoot dry weight, yield and yield components, seed oil and protein contents of cultivars were measured. Increasing salinity caused significant reduction in plant height, root and shoot dry weight, yield and yield components, seed oil and protein contents of all cultivars. However, there were significant differences among the cultivars for measured traits for each salinity level. Based on seed oil yield data, Safiabad and Kraj at 0.0038ds.m<sup>-1</sup>, Safiabad and Ultan at 4.89ds.m<sup>-1</sup>, Ultan, Safiabad and Darab at 8.61 salinity levels were the superior cultivars. High variability in tolerance to salinity among the tested sesame cultivars suggests that selection of more salt tolerant cultivars for planting or breeding purposes is possible.</span></p><p class="emsd-body"><span lang="EN-GB">Highlights</span></p><p class="emsd-body"><span lang="EN-GB">Effects of contrasting salinity levels (0.0038 (tap water as control), 4.89, 8.61, 10.5, 14.54, 17.74 ds.m<sup>-1</sup>NaCl) on sesame cultivars were tested. Salinity reduced plant growth and yield and seed oil and protein contents. However, there were significant differences among the cultivars for measured traits for each salinity level. </span></p>

scholarly journals Isolation and Characterization of a Mutant of the Marine Bacterium Alcanivorax borkumensis SK2 Defective in Lipid Biosynthesis

2010 ◽  
Vol 76 (9) ◽  
pp. 2884-2894 ◽  
Author(s):  
Efraín Manilla-Pérez ◽  
Alvin Brian Lange ◽  
Stephan Hetzler ◽  
Marc Wältermann ◽  
Rainer Kalscheuer ◽  
...  
Keyword(s):  
Carbon Source ◽  
Sole Carbon Source ◽  
Marine Bacterium ◽  
Neutral Lipids ◽  
Nile Red ◽  
Dry Weight ◽  
Wax Ester ◽  
Gene Encoding ◽  
Isolation And Characterization ◽  
Key Enzyme

ABSTRACT In many microorganisms, the key enzyme responsible for catalyzing the last step in triacylglycerol (TAG) and wax ester (WE) biosynthesis is an unspecific acyltransferase which is also referred to as wax ester synthase/acyl coenzyme A (acyl-CoA):diacylglycerol acyltransferase (WS/DGAT; AtfA). The importance and function of two AtfA homologues (AtfA1 and AtfA2) in the biosynthesis of TAGs and WEs in the hydrocarbon-degrading marine bacterium Alcanivorax borkumensis SK2 have been described recently. However, after the disruption of both the AtfA1 and AtfA2 genes, reduced but substantial accumulation of TAGs was still observed, indicating the existence of an alternative TAG biosynthesis pathway. In this study, transposon-induced mutagenesis was applied to an atfA1 atfA2 double mutant to screen for A. borkumensis mutants totally defective in biosynthesis of neutral lipids in order to identify additional enzymes involved in the biosynthesis of these lipids. At the same time, we have searched for a totally TAG-negative mutant in order to study the function of TAGs in A. borkumensis. Thirteen fluorescence-negative mutants were identified on Nile red ONR7a agar plates and analyzed for their abilities to synthesize lipids. Among these, mutant 2 M131 was no longer able to synthesize and accumulate TAGs if pyruvate was used as the sole carbon source. The transposon insertion was localized in a gene encoding a putative cytochrome c family protein (ABO_1185). Growth and TAG accumulation experiments showed that the disruption of this gene resulted in the absence of TAGs in 2 M131 but that growth was not affected. In cells of A. borkumensis SK2 grown on pyruvate as the sole carbon source, TAGs represented about 11% of the dry weight of the cells, while in the mutant 2 M131, TAGs were not detected by thin-layer and gas chromatography analyses. Starvation and lipid mobilization experiments revealed that the lipids play an important role in the survival of the cells. The function of neutral lipids in A. borkumensis SK2 is discussed.

scholarly journals THE INFLUENCE OF SPRAYING WITH POTASSIUM SILICATE AND IRRIGATION WITH SALINE WATER IN SANDY SOIL ON Calendula officinalis L.

2019 ◽  
pp. 39-56
Keyword(s):  
Agricultural Research ◽  
Saline Water ◽  
Tap Water ◽  
Block Design ◽  
Foliar Spray ◽  
Dry Weight ◽  
Potassium Silicate ◽  
Research Station ◽  
Calendula Officinalis ◽  
Calendula Officinalis L

Two pots experiments were conducted at the Experimental Farm of El-Qassasin Horticultural Research Station, Agricultural Research Center, Ismailia Governorate, Egypt, during two successive seasons of 2016/2017 – 2017/2018, to investigate the effect of potassium silicate at (0, 4, 6, and 8 cm3/l) as a foliar spray under different levels of water salinity (tap water, 1000, 2000 and 3000 ppm) on Calendula officinalis L. plant. The experiment was performed in complete randomized block design as factorial experiment with 3 replicates. The obtained results cleared that using salinity levels decreased growth parameters (plant height, number of branches/plant, fresh and dry weights of herb/plant), flowering parameters (flower diameter, number of flowers/plant, fresh and dry weight of flowers (g/plant) during eight cuts and fresh and dry weight of flowers (g/plant/season)) and chemical constituents (chlorophyll a, chlorophyll b, carbohydrate and carotenoid contents) compared to control. Moreover, the highest values in these parameters were registered by potassium silicate at 8 cm3/l concentration. Proline content increased in leaves with using saline water at 3000 ppm + potassium silicate at 8 cm3/l. Generally, it could be concluded that potassium silicate at 8 cm3/l, showed a uniform impact in alleviating inhibition of Calendula officinallis L. plant growth and productivity under moderate salinity stress condition.

scholarly journals Comparative study of procedures for isolation and cultivation of Legionella pneumophila from tap water in hospitals.

1993 ◽  
Vol 31 (5) ◽  
pp. 1213-1216 ◽  
Author(s):  
F F Reinthaler ◽  
J Sattler ◽  
K Schaffler-Dullnig ◽  
B Weinmayr ◽  
E Marth
Keyword(s):  
Comparative Study ◽  
Legionella Pneumophila ◽  
Tap Water

Extraction and Characterization of Gibberellins from Hordeum vulgare L. Seedlings

1974 ◽  
Vol 1 (2) ◽  
pp. 183 ◽  
Author(s):  
KF Faull ◽  
BG Coombe ◽  
LG Paleg
Keyword(s):  
Mass Spectrometry ◽  
Dry Weight ◽  
Paper Electrophoresis ◽  
The Other ◽  
Gas Chromatography Mass Spectrometry ◽  
Gas Liquid Chromatography ◽  
Fresh Weight ◽  
Hordeum Vulgare L ◽  
Layer Chromatography

Two gibberellins, one GA1-like, the other GA3-like, were identified in the extracts of roots and tops of 8-,11- and 15-day-old barley seedlings by paper chromatography, paper electrophoresis, thin-layer chromatography, gas-liquid chromatography and bioassay procedures, followed by combined gas chromatography-mass spectrometry. The amounts of gibberellins in the seedlings ranged from 7 to 11 ng per plant. The concentrations of gibberellins in the seedlings were 32-320 ng/g dry weight and 5-28 ng/g fresh weight; concentrations in the roots were higher than those in the shoots.

scholarly journals Antimycobacterial potential of the juniper berry essential oil in tap water

2018 ◽  
Vol 69 (1) ◽  
pp. 46-54 ◽  
Author(s):  
Dolores Peruč ◽  
Ivana Gobin ◽  
Maja Abram ◽  
Dalibor Broznić ◽  
Tomislav Svalina ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Mycobacterium Avium ◽  
Morphological Changes ◽  
Tap Water ◽  
Microscopic Analysis ◽  
Water Systems ◽  
Hot Water ◽  
Gas Chromatography Mass Spectrometry ◽  
Mediterranean Plants ◽  
Common Juniper

Abstract Mycobacterium avium complex-related diseases are often associated with poorly maintained hot water systems. This calls for the development of new control strategies. The aim of this study was to investigate the activity of essential oils (EOs) from the Mediterranean plants, common juniper, immortelle, sage, lavandin, laurel, and white cedar against Mycobacterium avium ssp. avium, Mycobacterium intracellulare, and Mycobacterium gordonae in culturing broth and freshwater as their most common habitat. To do that, we developed a new method of water microdilution to determine their minimal effective concentrations (MEC). The most active EO was the one from the common juniper with the MEC of 1.6 mg mL-1. Gas chromatography / mass spectrometry the juniper EO identified monoterpenes (70.54 %) and sesquiterpenes (25.9 %) as dominant component groups. The main monoterpene hydrocarbons were α-pinene, sabinene, and β-pinene. The juniper EO significantly reduced the cell viability of M. intracellulare and M. gordonae at MEC, and of M. avium at 2xMEC. Microscopic analysis confirmed its inhibitory effect by revealing significant morphological changes in the cell membrane and cytoplasm of all three bacteria. The mode of action of the juniper EO on the cell membrane was confirmed by a marked leakage of intracellular material. Juniper EO has a great practical potential as a complementary or alternative water disinfectant in hot water systems such as baths, swimming pools, spa pools, hot tubs, or even foot baths/whirlpools.

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