The phospholipid fatty acid (PLFA) pattern was analyzed in a forest humus and in an arable soil experimentally polluted with Cd, Cu, Ni, Pb, or Zn at different concentrations. In both soil types, there were gradual changes in the PLFA patterns for the different levels of metal contamination. The changes in the forest soil were similar irrespective of which metal was used, while in the arable soil

A major problem in accurately defining bacterial adhesion mechanisms and processes occurring in biofilms on surfaces is the lack of techniques that nondestructively provide on-line information about the microorganisms, their extracellular polymers, and metabolites. The attenuated total reflectance (ATR) technique of Fourier transform infrared spectroscopy (FT-IR) is ideally suited to monitor molec

Several studies have indicated that the capture of nematodes by the nematophagous fungus Arthrobotrys oligospora is mediated by a lectin on the fungal surface. One of the major surface proteins of this fungus showed haemagglutinating activity and was isolated by affinity chromatography using a mucin Sepharose column. Biochemical analysis showed that the protein was a dimeric glycoprotein with a mo

The adhesion mechanisms in three nematophagous fungi are reviewed. In all these fungi the infection and subsequent digestion of nematodes is initiated by the firm adhesion of the fungus to the nematode surface. In Arthrobotrys oligospora the adhesive phase is restricted to special three-dimensional structures. Drechmeria coniospora conidia attach to the nematode cuticle by an adhesive bud while Ca

The nematophagous fungus Arthrobotrys oligospora produced extracellular proteases when grown in a liquid culture, as revealed by measuring the hydrolysis of the chromogenic substrate Azocoll. The extracellular protease activity was inhibited by phenylmethylsulfonyl fluoride (PMSF) and other serine protease inhibitors and partly inhibited by the aspartate protease inhibitor pepstatin and by a cyste

Chemical speciation and partitioning of radiolabeled HgCl2 were studied in model aquatic systems consisting of undisturbed entrophic lake sediment and water in plastic cylinders. The cylinders were either gradually made anaerobic by a gentle flow of N2-CO2 or kept aerobic by air flow. The proportion of methylated 203Hg was significantly higher, in both water and sediment, in the anaerobic systems

The use of total lipid phosphate as a measure of biomass was evaluated in soils with different organic matter content. Lipids were extracted with a one-phase mixture of chloroform, methanol, and a buffer, and digested with either persulfate or perchloric acid to liberate lipid-bound phosphate. This procedure was evaluated by varying the extraction buffer, the extraction and digestion times, the am

Examination of ester-linked phospholipid fatty acids (PLFA) have provided a means to characterize the community structure of microbial assemblies. Attempts to analyze such acids at low picomolar levels in environmental samples by gas chromatography and chemical ionization mass spectrometry (CIMS) using positive or negative ion detection, showed that the limit of detection (LOD) was mainly dependen

In Salix myrsinifolia-phylicifolia, males and females produced approximately the same number of catkins per individual, but males produced more flowers per catkin. Females had a higher concentration of sugars in the nectar than males, but the standing crop of nectar did not differ between sexes. Females had a hexoserich nectar, males a sucrose-dominated nectar. Bumblebees discriminated between mal

The nematophagous fungus Arthrobotrys oligospora captures nematodes using adhesive polymers present on special hyphae (traps) which form a three-dimensional network. To understand further the adhesion mechanisms, A. oligospora surface polymers were visualized by transmisson electron microscopy and characterized by chemical methods. Both traps and hyphae were surrounded by a fibrillar layer of extr

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

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

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

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

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.

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

The therapeutic management of Sjögren syndrome (SjS) has not changed substantially in recent decades: treatment decisions remain challenging in clinical practice, without a specific therapeutic target beyond the relief of symptoms as the most important goal. In view of this scenario, the European League Against Rheumatism (EULAR) promoted and supported an international collaborative study (EULAR S

A semi-analytic model is developed to describe the flow through an inlet between a lagoon and the sea due to a simple tide and the related morphological response of the inlet. The governing equation for the water level variation in the lagoon is derived from the continuity and momentum equations and then solved for quasi-steady conditions yielding analytic expression for the main flow-related prop