[Bacteriologic and virologic hygienic studies on waste water ponds]. / Bakteriologische und virologische Hygieneuntersuchungen an Abwasserteichen.

Many problems arise with the overflow of wastewater after heavy rainfalls. Therefore a research project was started to investigate the possibilities of biological treatment for such sporadically occurring sewage. In this paper a helophyte bed is compared with a simple wastewater pond regarding virological and bacteriological hygiene parameters. The number of coliphages is an evident indicator for enteroviruses and its enumeration can be done easily and safely. It is suggested that the kind of sewage treatment described here is not suitable for municipal wastewater but for domestic sewage in the countryside. Furthermore the quantification of coliphages should become a constant part of routine hygiene examination.

Serological responses to herpes simplex virus type 1 (HSV-1) analysed with enzyme-linked immunosorbent assay (ELISA) and western blot (WB).

Serological response of 56 patients to primary and recurrent herpes simplex virus type 1 (HSV-1) infection were studied by enzyme-linked immunosorbent assay (ELISA) and by Western blot analysis (WB). ELISA test showed a high sensitivity in detecting IgG, IgM, and IgA antibodies. From 27 patients with recurrent infection, 13 (48%) had IgM antibody. The percentage of patients positive for IgA was similar among those with primary (72.4%) or recurrent (81%) infection. The band pattern in WB alone did not allow to distinguish between patients with primary or recurrent infections. Furthermore, no correlation between the particular viral proteins and clinical manifestation could be determined. The kinetics of antibody response could be followed with both methods.

[Electron microscopy of extracellular polymeric substances in activated sludge]. / Elektronenmikroskopische Darstellung extrazellulärer polymerer Substanzen in Belebtschlammflocken.

Many problems arise with the TEM preparation of activated sludge flocs because the specimen material contains up to 98% of water. It is difficult to preserve the ultrastructure beyond dehydration and to make the polymers visible, which cannot be visualized with standard methods. The method presented here renders satisfying results. The important role of the exocellular polymers for the structure, size and density of flocs can be well illustrated. Furthermore many structure patterns could be found differing largely from each other but occurring regularly as structure elements.

[Scanning electron microscopic studies of the microbial colonization of slow sand filters]. / Rasterelektronenmikroskopische Untersuchung über die mikrobielle Besiedlung von Langsamsandfiltern.

Using scanning electron microscopy (SEM), we studied the periphyton on the filter material of slow sand filters (SSF)--main basins--from the water-works in Geisecke/Ruhr. Table 1 presents information about the quantitative vertical distribution of the filter material with its size and shape, water-storage, nutrient content and the presence of bacteria. The proportion of microbial growth to microbial content was high with 80% found in the upper and about 70% in the lower part of the filter body. Larger sand particles supported proportionally higher populations than did small grains. Depressions were well populated. Heavier microbial concentrations resulted in attachment and colonization on exposed grain surfaces. Only some microorganisms adhered through slime-nets and stalks, and no sample showed any general or special mechanisms. The photographic reproduction of the effects was difficult, because of the amount of adherent organic and inorganic matter as well as the different topographic surfaces of the grains. Therefore we have not attempted a quantitative evaluation. 3 plates with SEM micrographs show the locations of colonizing bacteria on sand grains and organisms and their mode of attachment.

Microbial communities in the saturated groundwater environment I: Methods of isolation and characterization of heterotrophic bacteria.

In this paper we present a method of isolation and morphological and physiological characterization of groundwater bacteria based on numerical taxonomy and cluster analysis, and using a miniaturized test system (microtiter plates). Bacteria were isolated randomly on P-agar, and each strain was characterized in regard to 155 features. The media for biochemical differentiation are listed as well as methods of morphological discrimination. 246 strains of heterotrophic and oligotrophic bacteria, isolated from five water samples from different depths of the saturated groundwater area, were used for optimizing media and test reactions.

Microbial communities in the saturated groundwater environment II: Diversity of bacterial communities in a Pleistocene sand aquifer and their in vitro activities.

Bacterial cell numbers obtained from 103 water and sediment samples from a Pleistocene sandy aquifer in the Lower Rhine region (Bocholt, FRG) were determinated on P-agar and by direct count. Below 5 m under the surface, colony-forming unit (cfu) numbers in water samples were less than 100/ml, and in many cases less than 50/ml. In sediment samples, they were 10- to 100-fold higher (10(2)-10(4) cfu/g dry wt), but changing markedly between different depths. Direct cell counts yielded numbers two to three orders of magnitude higher.About 2,700 strains of bacteria from 60 samples were isolated randomly and characterized by morphological and physiological properties. Of all the isolates, 71.6% were gram-negative, and 52.2% were gram-negative straight rods. Water communities, with one exception, had low proportions of gram-positive bacteria (<11%), whereas in all but one of the sediment communities percentages of gram-positive isolates were three- to sevenfold higher (35-43%). Water and sediment communities, as well as communities from different sampling sites and communities from different depths of the same sampling site, differed in their qualitative and quantitative morphotype composition and physiological capabilities.The in vitro activities of strains within a single community were quite different, indicating that each community is composed of many diverse bacteria, several having extremely different capabilities. Thus, each community has its own specific activity pattern. Gram-positive bacteria showed on an average lower total activities than did gram-negative bacteria. Grampositive bacteria as well as gram-negative bacteria from sediment had higher values of in vitro activities than the corresponding groups isolated from water. Many water and sediment bacteria preferred the same substrates which were utilized at high rates. However, there were differences in the degradation of the various other substrates present, and each community showed preferences for particular substrates, which they degraded best.The results of cell morphology and physiology studies indicated that all eight characterized communities were very different from one another and very diversely structured.