5- (and 6-)Sulfofluorescein diacetate (SFDA), which is converted to a fluorescent product by intracellular esterase activity, was used to stain living microorganisms, including bacteria, Saccharomyces cerevisiae, and fungi, in soil. SFDA (1 mM) dissolved in ethyl alcohol was added to an intact soil sample, and the preparation was examined with an epifluorescence microscope. Bright single cells and colonies of live bacteria were observed without interference from the autofluorescence of soil minerals and detritus. Cultured Escherichia coli was killed through heat treatment; thus, SFDA was concluded to stain only living cells. Microbial colonies obtained from natural soils and various cultured strains were tested. It was found that 151 of 154 colonies from natural soils were stained and that hyphae and spores from 1 of 28 cultured microbial strains were not stained. The SFDA method was successfully used to visualize and count bacteria in soil samples from Mount Shiga in Japan.

Waste drilling-fluid-utilising microorganisms were isolated from drilling-mud cuttings, soil and creek water from a mangrove swamp oilfield location in the Delta area of Nigeria using waste drilling-fluid as the substrate. Eighteen bacterial isolates obtained were identified as species of Staphylococcus, Acinetobacter, Alcaligenes, Serratia, Clostridium, Enterobacter, Klebsiella, Nocardia, Bacillus, Actinomyces, Micrococcus and Pseudomonas, while the genera of fungi isolated were Penicillium, Cladosporium and Fusarium. Even though drilling-fluid-utilising genera were in higher numbers in the soil than in the two other sources examined, the percentages of the total heterotrophic bacteria that utilised waste drilling-fluid were 6.02 in the drilling-mud cuttings, 0.83 in creek water and 0.42 in soil. The screen tests for biodegradation potential of the bacterial isolates showed that, even though all the isolates were able to degrade and utilise the waste fluid for growth, species of Alcaligenes and Micrococcus were more active degraders of the waste. The significance of the results in environmental management in oil-producing areas of Nigeria is discussed.

Various species of nitrogen-fixing microorganisms were used in the investigation. The effectiveness of the studied species of nitrogen-fixing microorganisms depended on the nitrogen-fixing microorganisms and plant genotype and on the quantity of mineral nitrogen applied. The best and the worst effectiveness of the studied nitrogen-fixing microorganisms was achieved with the varieties PKB-111 and PKB-Lepoklasa, respectively. Azotobacter chroococcum and Beijerinckia Derx expressed the best effectiveness with PKB-Lepoklasa and PKB-111, respectively. Increased quantities of mineral nitrogen decreased the effectiveness of the studied species of nitrogen-fixing microorganisms. The application of highly effective nitrogen-fixing microorganisms in winter wheat can substitute a certain quantities of mineral nitrogen by biological nitrogen and increases yield.

A comparison of the efficiency of some preservatives used for instrumental analysis of microflora composition of milk is presented. The preservatives used in the trial involved potassium bichromate, Milkofix preparation on the basis of colloidal silver, sodium azide and Bronopol. Groups of microorganisms (mesophile microorganisms, coliform microorganisms, lactic fermentation bacteria, enterococci and staphylococci) were selected with respect to their expected occurrence with natural contamination of milk. There were highly significant differences (P=0.01 %) between the preservatives in preservation effect shown as the number of colonies of the particular groups of bacteria. The best preservation effect was determined in Bronopol for all groups of microorganisms somewhat worse preservation capacity was found out in potassium bichromate. Sodium azide and Milkofix had similar preservation characteristics; they had equivalent effects on lactic fermentation bacteria, Milkofix was more efficient in inhibition of enterococci while sodium azide was more efficient against mesophile microorganisms. The studied groups of bacteria can be divided on the basis of sensitivity to the used preservatives into organisms sensitive to preservatives including staphylococci and coliform microorganisms, and tolerant organisms that can grow even in the presence of preservatives, including enterococci, lactic fermentation bacteria and mesophile microorganisms.

To improve the flavor of modern cured meat products by means of microorganisms, Parma ham can serve as a model. Therefore, 29 dry-cured Parma hams representing six different stages in the manufacturing process were examined to reveal the relationship between the formation of flavor and the occurrence of microorganisms. Quantities of volatile compounds, chemical changes, sensory profiles, and quantitative isolation of microorganisms showed that flavor formation can be divided into two phases, the first including salting, drying, and ripening and the second including only ripening and postripening. The first phase is characterized by autoxidation, while the second phase reflects secondary metabolism of microorganisms, especially amino acid catabolism. The results suggest that flavor-improving microorganisms should possess a secondary metabolism which generates methyl-branched aldehydes, secondary alcohols, methyl ketones, ethyl esters, and dimethyl trisulfide in a distinct balance.

Decomposition dynamics of chloranilines (CA) in liquid media and soil suspensions inoculated with pure cultures able to degrade these compounds was studied. A strong dependence was established (with correlation 0.69 - 0.99) between the CA half-decomposition time, t0.5, and the logarithm of the initial concentration of CA-degrading microorganisms, x0. This dependence was approximated by a linear equation logx0=c-dt0.5, where c and d are empirical coefficients. As shown by kinetic analysis, this relationship holds if microorganism growth on the introduced substrate proceeds exponentally with a constant specific growth rate, Mm, and a constant biomass yield, Y, and without a lag phase. In this case, the coefficients c and d of the regression equation are equal to log(Ys0/2) and Mmloge, respectively, where s0 is the initial CA concentration in the solution. On this basis, a method for determining the total amount of CA-degrading microorganisms in soil was proposed. It consists of measuring the CA half-degradation time in the soil suspension and calculating the value of x0 with the use of coefficient c and d obtained for freshly grown bacterial strains. The proposed method is very sensitive, accurate, and yields reproducible results. It is easy to implement, and the analysis time does not normally exceed 4 to 6 days. The lower threshold for detection of CA-degrading microorganisms in soil is 10** (-11) mg/g soil, which corresponds to a population density of less than one cell per gram of soil

In a four-year field trial comparing four different maize cropping systems (conventional cropping, intercropping, maize with rye cover crop, and maize meadow) the earthworm and collembola populations as well as several activities of soil microorganisms were determined. Vegetation between the maize rows was beneficial to animals and soil microorganisms. This cover not only provided nutrients but created also a favourable microclimate. In maize meadow, which was never tilled except in the seed band, earthworm and collembola populations were highest. The large vegetation mass and root production of the rye system particularly stimulated the soil microorganisms