METHOD OF IDENTIFYING MICROBIAL CONTAMINATION OF AN AQUEOUS MEDIUM BY ANALYZING ENZYME DEHYDROGENASE ACTIVITY Russian patent published in 2020 - IPC G01N33/18 G01N21/78 

FIELD: ecology.

SUBSTANCE: invention relates to geoecology and can be used for identification of microbial contamination of aquatic environment. For this purpose, grazing area is determined on the territory of pastoral cattle breeding, according to a map-scheme of large scale, M 1:200,000 and larger. Then averaged representative sample of manure is taken from grazing place, which is dried (at room temperature) and sieved (through sieve with cell diameter of 3 mm) to obtain dry sample. Sample is sampled with weight of 1 g in amount of 5 batches of 6 each; i.e. total 30 samples. First batch is dry samples of manure and goes under number No.1 (manure : water ratio in it is equal to 1:0). Remaining 4 batches of dry samples of manure are placed into centrifugal tubes on a filter paper with pore size of 12–15 mcm (for example, "Black Ribbon" according to international classification). Then distilled water is added to the test tubes without mixing with the sample in manure : water ratio equal to 1:1 for the second batch, 1:2 for the third batch, 1:3 for the fourth batch and 1:4 for the fifth batch. Thus, low-volume humidity of manure is simulated, which is characteristic in case of rain (manure : water ratio within 1:1÷1:2), and high-volume humidity of manure, which is characteristic in case of snow thawing (manure : water ratio within 1:3÷1:4). Centrifugal test tubes with samples are inserted into the centrifuge rotor and centrifuged at the same time for at least 5 minutes to obtain water samples of manure from them, respectively, under numbers No.2, No.3, No.4 and No.5. After that each sample of the first batch and each water sample of the remaining batches is placed into individual modified Erlenmeyer flasks with addition of the required reagents and incubated in a thermostat at +30 °C for one day. After the incubation is completed, the activity of the dehydrogenase enzyme is analyzed in samples No.1, No.2, No.3, No.4 and No.5 using a spectrophotometric method with the required mathematical processing of the obtained results for each batch of samples.

EFFECT: higher efficiency and simplification of identification.

1 cl, 2 dwg, 1 tbl