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Infrared monitoring of the adhesion of Catenaria anguillulae zoospores to solid surfaces

Electron microscopic studies of nematodes infected with the chytridiomycetous fungusCatenaria anguillulae indicated that zoospores of the fungus adhered to the cuticle of nematodes by a layer of extracellular polymers. The chemical composition of the adhesive polymers and their interaction with a solid surface were examined with Fourier transform infrared spectroscopy, using an attenuated total re

Importance of leaf litter fragmentation for bacterial growth

Four fragment size groups of maple leaf litter (Acer platanoides) were leached with sterile water. The fragments and leachates were inoculated with bacteria isolated from maple leaf litter and bacterial activity and growth were determined. About 80-90% of the dissolved organic carbon (DOC) released from the leaf fragments was released during the 1st day; the release was negatively correlated with

Analysis of carbon steels affected by bacteria using electrochemical impedance and direct current techniques

The failure of metal structures in contact with natural, untreated waters is frequently ascribed to bacterial corrosion. This study compares the corrosive effects of Vibrio natriegens (V. natriegens) when in batch and continuous flow culture. Evidence is presented for enhanced corrosion of carbon steel resulting from aerobic culture of V. natriegens with two sulfate-reducing bacteria (SRB). The co

Growth of bacteria in the rhizoplane and the rhizosphere of rape seedlings

The growth of 10 isolates of rhizosphere bacteria was compared in the rhizoplane (RP), rhizosphere (RS) and non-rhizosphere soil of a model system with rape seedlings growing in sterile sand. The colonization of the RP differed little among isolates. However, the bacterial isolates differed according to their degree of dependence on the root for growth, as judged by RS:RP and plant:non-plant ratio

Differences in lipid composition between free-living and initially adhered cells of a Gram-negative bacterium

The phospholipid fatty acid composition and poly-β-hydroxybutyrate (PHB) content of initially adhered and free-living cells of a Pseudomonas sp. isolated from the rape plant Brassica napus were examined with gas chromatography (GC). Five different adhesion experiments were made including variations in surface charge (hydrophilic and lipophilic), temperature, media composition and time of adhesion.

Mass spectrometric determination of selected microbial constituents using fused silica and chiral glass capillary gas chromatography

Applications of quantitative gas chromatography/mass spectrometry (selected ion monitoring) to clinical and ecological microbiology are described. The technique permits determination of selected microbial metabolites and can be used for the rapid diagnosis of, for example, tuberculosis by ion-focusing of specific branch-chain fatty acids. The technique is also used to determine diaminopimelic and

Determination of 13C-enrichment in bacterial fatty acids using chemical ionization mass spectrometry with negative ion detection

Saturated, monoenoic and β-hydroxysubstituted fatty acids, 13C-labelled at the carboxyl group, were prepared from natural or synthetic unlabelled analogues. The synthetic route involves decarboxylation of the unlabelled fatty acid to the next lower iodide, displacement of iodide for [13C]cyanide and hydrolysis. The fatty acids were converted to their pentafluorobenzyl esters and analysed by select

Recycling of fecal pellets in isopods : Microorganisms and nitrogen compounds as potential food for Oniscus asellus L

The isopod Oniscus asellus was fed wood pieces. The fecal pellets produced during 6 days were reingested twice. Both fresh and ageing pellets were examined for microorganisms and nitrogen compounds including proteins and bacterial cell wall compounds, d-alanine and diaminopimelic acid. In old pellets, the plate counts of fungi decreased but that of bacteria as well as the concentrations of protein

Pollination by deceit, floral sex ratios and seed set in dioecious Rubus chamaemorus L.

Male and female flowers of the dioecious perennial herb Rubus chamaemorus L. are similar in general appearance. However, female flowers are somewhat smaller, do not produce any pollen, and contain very small amounts of nectar. Syrphids and bumblebees, which are important pollinators of R. chamaemorus, showed a strong preference for male flowers. Male flowers were also less often rejected by flower

Model system for studies of microbial dynamics at exuding surfaces such as the rhizosphere.

An autoclavable all-glass system for studying microbial dynamics at permeable surfaces is described. Standard hydrophobic or hydrophilic membranes (46-mm diameter) of various pore sizes were supported on a glass frit through which nutrient solutions were pumped by a peristaltic pump. The pump provided a precisely controlled flow at speeds of 0.5 to 500 ml of defined or natural cell exudates per h,

Chemical changes in cell envelope and poly-β-hydroxybutyrate during short term starvation of a marine bacterial isolate

Qualitative and quantitative changes were observed in lipids, poly-β-hydroxybutyrate (PHB), and a cell wall peptidoglycan consitutent in a marine bacterial isolate during starvation for 24 h in an energy and nutrient-free medium. While the amount and composition of the membrane fatty acids fluctuated within the first hours of starvation, the total amount of fatty acids decreased during the starvat

Physiological and morphological changes during short term starvation of marine bacterial islates

Three marine bacteria were examined for physiological and morphological changes in the initial phase of starvation. It was found that the starvation process was induced in a similar way irrespective of whether the cells were suspended in nutrient and energy free artificial seawater (NSS) or NSS supplemented with nitrogen and phosphorus. An initial phase of increased activity was consistent with a

Precision and sensitivity of the measurement of 15 N enrichment in D-alanine from bacterial cell walls using positive/negative ion mass spectrometry

Sensitive detection of cellular components from specific groups of microbes can be utilized as 'signatures' in the examination of microbial consortia from soils, sediments or biofilms. Utilizing capillary gas chromatography/mass spectrometry and stereospecific derivatizing agents, D-alanine, a component localized in the prokaryotic (bacteria) cell wall, can be detected reproducibly. Enrichments o

Diastereoisomeric determination of R‐alanine in bacteria using capillary gas chromatography and positive/negative ion mass spectrometry

The possibilities of using combined capillary gas chromatography mass spectrometry for highly sensitive and selective determinations of enantiomeric alanines of bacterial origin have been evaluated. The alanines were separated as their diastereoisomeric N‐heptafluorobutyryl‐2‐butyl ester derivatives on a 25 m fused silica capillary column coated with SE‐54 as stationary phase. The mass spectra of

Determination of microbial fatty acid profiles at femtomolar levels in human urine and the initial marine microfouling community by capillary gas chromatography-chemical ionization mass spectrometry with negative ion detection

Room temperature esterification with the electron capturing pentafluorobenzyl bromide in glass capillaries, with analysis by capillary gas-liquid chromatography coupled with chemical ionization mass spectrometry and negative ion detection in the selected ion mode, allowed detection and identification of fatty acids from microbial biofilms at the femtomolar level. This sensitivity was achieved wit

Capillary gas chromatography using electron capture or selected ion monitoring detection for the determination of muramic acid, diaminopimelic acid and the ratio of d/l-alanine in bacteria

Gas chromatographic analyses of muramic acid, diaminopimelic acid and D-alaline, which are specific components of the bacterial cell wall, have been performed using electron capture or selected ion monitoring detection. Intact cells or peptidogylycan preparations were hydrolyzed in HCl and DCl. After purification by cation exchange chromatography, followed by conversion to the N-heptafluobutyrliso

Emergency Department Workload and Crowding During a Major Electronic Health Record Breakdown

Background: Emergency Departments (EDs) today rely heavily on Electronic Health Records (EHRs) and associated support systems. EHR updates are known to be associated with adverse events, but reports on the consequences of breakdowns in EDs are lacking. Objectives: To describe the effects on workload, occupancy, patient Length Of Stay (LOS), and admissions at three EDs (a regional trauma center, a

The Offender, the crime and the victim

In addition to Malmö having the most reported crimes in relation to its population, it is also one of the cities in the country with the highest percentage of gun-related violence. Our earlier studies show that people who commit serious crimes such as homicide or attempted homicide in Malmö are primarily single, have no psychiatric diagnosis and mainly use knives or other sharp weapons to commit t