Sampling procedure

Field soil for microbiological analyses will be sampled from the layer 0-20 cm with the soil stock. The leaves and stones and other material from the soil surface will be removed. For each sampling site (point), about 40 subsamples will be taken with the soil stock, and then joined to an average soil sample. The analysis shell be done immediately after sampling, if it is possible. In the other case, the samples shell be stored without drying in the temperature 4°C.

Incubation of soil samples in the laboratory conditions

For laboratory investigations, soil samples will be incubated in plastic bags, by 60% of the maximal field water capacity and temperature 20°C (if specific other conditions are not required in experiment). The water content will be supplemented with dest. water. Before sampling, content of the plastic bag will be carefully mixed.

EXPERIMENTAL INSTRUMENTS

Bioscreen

The Bioscreen instrument from Labsystem Corp. is a equipment to measure of the microbial growth, up to 200 samples simultaneously. The changes in the optical density of the medium with culture allow obtaining a growth curves. It is possible to test the sensibility of bacterial strains to stress factors or determine the counts of microorganisms in different samples.

BacTrac 4100

BacTrac 4100, produced by Sy-Lab VgmbH, Austria, is an instrument to determinate the microorganisms growth by measuring the changes in the impendance of the culture medium. It is possible to detect the changes in growth intensity and determine the microbial counts in different samples.

Ultragas U4S

Automatic CO2 analyser produced by Wöhstoff OHG, Germany. Permanent determination of carbon dioxide evaluated from soil with conductometric method. The sensibility is 0,0001% vol.

METHODS

Determination of the soil microbial biomass (SIR-method)

The amount of microbial biomass in soil will be analysed using a physiological method (Anderson and Domsch 1978). Maximal initial respiration rate of the soil is determined. Then, the soil is amended with adequate amount of glucose as mixture with talcum (1:5) and the CO2 production measured during 3 hours (in temperature 22°C). The amount of microbial biomass is calculated from the equation: y = 40,04x + 0,37 (where x = CO2 production, y = microbial biomass).

Determination of the count of: bacteria, actinomyces, fungi, amylolitic organisms, proteolitic organisms, lipolitic organisms in the soil

The count of bacteria, actinomyces, fungi, amylolitic organisms, proteolitic organisms, lipolitic organisms in the soil will be determined with plate dilution method, using adequate media: Bunt-Rovira for bacteria, Martin for fungi, Küster for actinomyces, Emerson for amylolitic organisms, Kedzia and Konar for proteolitic organisms, medium with tributirin for lipolitic organisms.

Cellulolitic activity of the soil

Cellulolitic activity of the soil will be determined with Kuzniar method. A sheets of cellulose will be deposed in soil for 1 month. The loo of weight of the sheets during this time is a measure of cellulolitic activity of the soil microflora.

Nitrification activity in the soil

Tested soil will be amended with 200 mg/kg (NH4)2SO4 and incubated in laboratory conditions for 21 days. The amount of the nitrate will be determined weekly with electron selective electrode or colorimetric with use of diphenylsuphonic acid. The increase of nitrate amount is a measure of the nitrification activity in soil.

REFERENCES

Anderson J. P. E., Domsch K. H. (1978). A physiological method for the quantitative measurement of microbial biomass in soils. Soil Biol. Biochem. 10, 215-221.

Bunt J. S., A. D. Rovira (1955). Microbiologocal studies of some subantarctic, J. Soil Sci., vol. 6, No 1, s. 119-128.

Burbianka M., Pliszka A., (1971) Mikrobiologia zywnosci. PZWN, Warszawa.

Cooney D. G., Emerson R.(1964), Termophilic fungi. Freeman and Co., London.

Fenglerowa W., (1965) Simple method for counting Azotobacter in soil samples Acta Microb. Pol. 14 (21)203.

Kedzia W., Konar H., (1974) Diagnostyka mikrobiologiczna, PZWL, Warszawa.

Küster E., S. T. Williams (1964). Selektion of Media for Isolation of Streptomycetes, Nature, London, 202, s. 928-929.

Martin J. P. (1950). Use acid rose bengale and strptomycin in the plate method for estimating soil fungi. Soil Sci.,6, s. 215-233.

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