SU1472507A1 - Method of estimating contamination process bacterial cultures - Google Patents

Abstract

The invention relates to the microbiological industry and can be used to determine the purity of bacterial cultures grown under industrial conditions. The purpose of the invention is to simplify the method. The essence of the method is that in the selected sample the initial value of EH is determined, then one of the substances that change the intracellular PH, propionate or sodium acetate, is added to the sample. N, Nb is dicyclohexylcarbodiimide or carbonyl cyanide m-chlorophenylhydrazone and the EH value is re-recorded. If the value of EH does not change, it is concluded that there is extraneous microflora. With a sharp decrease in the value of EH compared with the initial one, it is concluded that there is no contamination of the culture. 1 zp

Description

one

This invention relates to the microbiological industry and can be used to determine the purity of bacterial cultures grown under production conditions.

The purpose of the invention is to simplify the method

Example 1. 20 ml of the culture of the production strain Escherichia coli M-17 grown on synthetic medium M-9 with a pH of 7.3 and below, is placed in a cell to measure Eh. After 10-15 minutes, sodium acetate was introduced into the well to a final concentration of 15 mM / L. In pure culture, an abrupt drop in Eh is observed at one side of negative values. If E. coli-contamination culture on extraneous microflora, for example, Serratia marcescens, shows no change in Eh with the addition of sodium acetate in the early stages and an increase in Eh in the later stages of contamination is possible. The sensitivity of the method is 100: 1 - 1000: 1 (i.e. in 100-1000 parts of the main culture, the presence of 1 part of extraneous microflora is revealed).

Example 2. A 20 ml culture of Bacillus subtilis VKM 428 grown on synthetic medium M-9 with a pH of 7.2 and below is placed in a cell for measuring Eh. As a reagent that causes changes in the intracellular pH, alcohol is added to the cell.

1HE SP

carbonyl cyanide m-chlorophenylhydrazone solution (Z.Z-Yu M / l). By the absence of a jump in Eh in the region of negative values, the presence of extraneous microflora in the culture is detected,

Example 3 The determination conditions are similar to those described in examples 1-2, except that 20 mM / l of EDTA is added to the culture taken from the fermenter and an alcohol solution is used as the agent that causes the change in intracellular pH. W, I-di-cyclohexylcarbodiimide, adding it to the measuring cell to a final concentration of 10 M / l. By the absence of a jump in Eh in the region of negative values, the presence of extraneous microflora in the culture is detected.

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The use of the method simplifies the control of the purity of the culture in laboratory and industrial conditions, reduces the time of testing, increases the sensitivity and does not require expensive equipment. When used as reagents.

by changing the intracellular pH, weak penetrating acids like acetate, the method can be applied directly in the fermenter during the cultivation of bacteria.

Claims (1)

Invention Formula  The method for determining contamination of industrial bacterial cultures by registering a change in a physical parameter in crop samples, characterized in that, in order to grow the method, the initial value of Eh is measured in the test sample, then the substance that changes the intracellular pH is added, the value of Eh is re-measured and the purity of the culture is determined by its decrease in comparison with the initial value, and in the absence of a change in the value of Eh, the presence of contamination is determined, 2, Method pop, I, and Y and. so that sodium acetate, sodium propionate, M, w-dicyclohexylcarbodiimide or carbonyl cyanide m-chlorophenylhydrazone are used as the substance that changes the intracellular pH.