In a purchasing district of two dairies in the South Bohemian region, total counts of mesophilic aerobic and facultatively anaerobic microorganisms were investigated in samples of raw milk from different farms and in bulk samples of milk supplied to dairies; this investigation folowed a modification of the standard of evaluation of microbiological quality of raw milk. It was found out that in the course of several months the total counts of microorganisms in bulk samples were considerably reduced. Most farms began to produce grade A milk, which can contain maximally 500 000 microorganisms per 1 ml milk; an overall average was about 400 000 microorganisms per 1 ml. The samples of bulk milk of tanks still had high counts of microorganisms (about 800 000 per 1 ml); this suggests that the microbiological quality of raw milk continues to be a topical problem, and its solution must be a complex one.

Hygienic conditions of milk production on ten farms of the Pozorice Cooperative Farm near Brno were investigated by means of a modified reductase test in 1989. Total counts of microorganisms and the group of coliform, thermophilic and psychrotrophic bacteria were investigated simultaneously. The correlation coefficients ranging from 0.587 to 0.973 were determined for the total counts of microorganisms and the Lakto-la-test in the quarters of the year. The values of the coefficients of correlation between the total counts of microorganisms and the number of coliform bacteria were significant (r=0.615 to 0.837). On the other hand, the values of the coefficients of correlation between the total counts of microorganisms and the counts of psychrotrophic microorganisms ranged from 0.234 to 0.749. The Lakto-la-test helps to find out and to reveal shortcomings of the hygiene of milk production; if it is used systematically, it contributes efficiently to an increase in the microbiological quality of milk.

It has been hypothesized that vegetation in certain ecosystems inhibits nitrification in soil by producing phenolic compounds that inhibit oxidation of ammonia by nitrifying microorganisms. This hypothesis is based largely on a report that very low concentrations (10(-6) M-10(-8) M) of several phenolic acids (notably ferulic acid) completely inhibited NO2- production in an aqueous suspension of soil treated with (NH4)2SO4 and a nutrient solution suitable for growth of Nitrosomonas and other autotrophic nitrifying microorganisms. To evaluate this hypothesis, we determined the effects of three phenolic acids (ferulic acid, caffeic acid, and p-coumaric acid) on nitrite production by representatives of three genera of terrestrial autotrophic nitrifying microorganisms (Nitrosospira, Nitrosomonas, or Nitrosolobus) grown on a defined medium containing NH4+. We found that nitrite production by the Nitrosospira was not inhibited by ferulic acid, caffeic acid, or p-coumaric acid at concentrations of 10(-6) or 10(-5) M and was only slightly inhibited when these acids were at a concentration of 10(-4) M. We also found that ferulic acid did not markedly inhibit nitrite production by the three genera of nitrifying microorganisms studied, even when its concentration was as high as 10(-3) M. These observations invalidate the hypothesis tested because the phenolic acids studied did not significantly retard ammonia oxidation by autotrophic microorganisms even when their concentration in cultures of these microorganisms greatly exceeded their concentrations in soils.

Various microorganisms inhabit at deep sea in spite of the severe circumstances such as high hydraulic pressure, low temperature and darkness. In order to study the deep sea microorganisms bionomics, high performance sampler would be necessary for collecting microorganisms and keeping the in site circumstances. The pressure-retaining type sampler was developed for deep sea microorganisms to the depth of 7,000m. The functional aspects of the deep sea sampler comprise the following: -to preserve the in site conditions, such as hydraulic pressure and temperature, -to collect the deep sea water to enrich microorganisms by filtration method without contamination, -to compose the sampler simplify and for easy handling. The sampling vessel was designed in keeping the pressure within 95% of the in site value by means of a pressure preservative device with gas accumulator. The sampling vessel was made of titanium alloy to minimize the weight so that the disjointed vessel would have high handling performance. Also, slide type valve with O-ring seals was used in the sampling vessel so that the leak tight reliability has been improved. The result of the field test to the depth of 5,600m confirmed the possibility to preserve the pressure above 95% compared with the in site pressure

The comparative accumulation and depuration processes for several microorganisms (Escherichia coli, Salmonella typhimurium, Vibrio parahaemolyticus, Aeromonas hydrophila, Streptococcus faecalis, Staphylococcus aureus, and MS-2 coliphage) by the striped venus, Chamelea gallina, under controlled laboratory conditions were studied. Microorganisms accumulated rapidly in bivalves during the first 6 h, with accumulation rates between 3.2 to 360.5 organisms/h depending on the type of microorganism. The relative patterns and rates of elimination of the microorganisms suggest that they are eliminated from shellfish in two different ways. One is of a mechanical nature that results in microbial elimination during the first 12 h. The other elimination mechanism depends upon the microbial species and their accumulated number. All microorganisms tested were eliminated completely by the molluscs after 3 d of depuration, except MS-2 bacteriophages. Results indicate that MS-2 coliphages may be a more reliable indicator of the microbial depuration efficiency by the shellfish under laboratory conditions than E. coli.

A protected catheter brush introduced by fiberoptic bronchoscopy was used to sample the tracheal and bronchial mucosa in 28 horses with small airway disease. Tracheal and bronchial brushings were examined for the presence of fungi, aerobic and anaerobic bacteria, and a cytoiogical evaluation was also done on fluid collected by the bronchoalveolar lavage (BAL) technique. Microorganisms (bacteria and fungi) were isolated more often in tracheal brushings (53.6%) than in bronchial brushings (10.7%). Anaerobic bacteria were not isolated. Results of this study indicate that fiberoptic bronchoscopy using a protected catheter brush is an easy and practical technique to obtain minimally contaminated samples for isolation of microorganisms from the lower respiratory tract of horses. However, no association was observed between isolation of high numbers of microorganisms from the bronchi and severity of small airway disease.

These proceedings contain seventeen review chapters ordered in four sections: 1. importance of invertebrates and microorganisms as components of biodiversity, 2. importance of biodiversity in sustaining soil productivity, 3. importance of biodiversity to pest occurrence and management and 4. biotechnology and biodiversity among invertebrates and microorganisms. Additions are discussions between participants, summaries by the chairman of the sessions, and a statement of the findings of the workshop

Bioluminescence provides a novel tool with which to probe in real time the recovery of microorganisms such as Salmonella typhimurium from sub-lethal injury, a condition of immense importance in the enumeration of microorganisms in food and environmental samples such as from estuarine waters. We describe the application of in vivo bioluminescence to monitor the recovery of S. typhimurium from freeze injury and, in addition, we explore the effect of multiple stress conditions on microbial recovery, where we compare bioluminescence with viable count measurement.

A genetically engineered microorganism, Pseudomonas putida PPO301 (pRO103), and the plasmidless parent strain, PPO301, were added at approximately 10(7) CFU/g of soil amended with 500 ppm of 2,4-dichlorophenoxyacetate (2,4-D) (500 microgram/g). The degradation of 2,4-D and the accumulation of a single metabolite, identified by gas chromatography-mass spectrophotometry as 2,4-dichlorophenol (2,4-DCP), occurred only in soil inoculated with PPO301(pRO103), wherein 2,4-DCP accumulated to >70 ppm for 5 weeks and the concentration of 2,4-D was reduced to <100 ppm. Coincident with the accumulation of 2,4-DCP was a >400-fold decline in the numbers of fungal propagules and a marked reduction in the rate of CO2 evolution, whereas 2,4-D did not depress either fungal propagules or respiration of the soil microbiota. 2,4-DCP did not appear to depress the numbers of total heterotrophic, sporeforming, or chitin-utilizing bacteria. In vitro and in situ assays conducted with 2,4-DCP and fungal isolates from the soil demonstrated that 2,4-DCP was toxic to fungal propagules at concentrations below those detected in the soil.