JP3141633B2 - Method for detecting surfactant-degrading microorganisms - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for detecting surfactant-degrading microorganisms. More specifically, the present invention relates to a method for detecting a surfactant-degrading microorganism by a simple qualitative method.

[0002]

2. Description of the Related Art In screening microorganisms, a method for simultaneously detecting several tens to several hundreds of samples at a time is desired. In screening for surfactant-degrading microorganisms, they are cultured in a medium containing a surfactant, and the culture is centrifuged to collect bacteria, and the supernatant is sterilized by a filter. As a degradation measurement sample, a method of measuring the degradation ability based on the rate of decrease in the elution ability of the surfactant with a differential refractometer before and after culturing has been performed.
This method can quantitatively measure the degradation ability, but in screening a large number of microorganisms, the first step is to qualitatively determine whether it has surfactant-degrading ability. Measurement results are required.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for screening a surfactant-degrading microorganism by a simple and qualitative method.

[0004]

SUMMARY OF THE INVENTION The object of the present invention is as follows.
After culturing microorganisms in a medium containing a surfactant, a polymer film is placed on the resulting colony to adsorb the surfactant in the medium, and the surfactant adsorbed film forms a complex salt with the surfactant. This is achieved by a method of immersing in a solution of the coloring substance to be obtained and detecting surfactant-degrading microorganisms according to the coloring state of the dried film.

Conventionally, a method using a coloring substance has been adopted for qualitative analysis of a surfactant. For example, in the case of an anionic surfactant, the methylene blue-chloroform method is used.
The bromophenol blue method is used for a cationic surfactant, the sodium tetraphenylboron complex back titration method is used for a nonionic surfactant, and the phosphotungstic acid method is used for an amphoteric surfactant. These methods are based on the principle that various surfactants form a complex salt with the corresponding coloring substance and are colored. In the method of the present invention, such a principle is effectively used.

In the method for detecting a surfactant-degrading microorganism according to the present invention, first, one or more microorganisms to be screened are separately inoculated in a medium containing a surfactant and cultured at 37 ° C. for a predetermined number of days. Thereafter, a polymer film is placed on each colony, and a surfactant or a decomposition product thereof is adsorbed on the film. As the polymer membrane, a nitrocellulose membrane, a polysulfone membrane, a polyvinyl alcohol membrane, or the like is used for each of the various microorganisms as one or a plurality of sheets.

Thereafter, the membrane is removed from the medium, immersed in a solution containing a coloring substance such as methylene blue, thymol blue, bromophenol blue, erythrosin, toluidine, etc., pulled up from the solution and air-dried. The decomposition activity of the surfactant is determined. That is, if the surfactant is not decomposed, the film is colored,
On the other hand, if decomposed, the degree of coloring is low.

[0008]

According to the method of the present invention, it is possible to easily and qualitatively confirm whether or not a target microorganism has a surfactant-decomposing ability, and to screen a large number of target microorganisms at one time. Can be.

[0009]

Next, the present invention will be described with reference to examples.

Example 1 MM medium containing 1% by weight of sodium alkylbenzenesulfonate [(NH ₄ ) ₂ SO ₄ 1 g / L, KH ₂ PO ₄ 10 g / L, MgSO ₄ .7H ₂ O
0.1 g / L, sodium citrate 0.5 g / L; pH 7.0 and agar added as a solidifying agent 15 g / L], and a polyethylene glycol-degrading microorganism, P. pseudoalkaligenis No.02A (FERM
P-13574; refer to Japanese Patent Application No. 5-107630) and B. subtilus
NIG 1121 was separately inoculated and cultured at 37 ° C for 5 days.

After the cultivation, a nitrocellulose membrane was placed on both colonies, and sodium alkylbenzenesulfonate or a decomposition product thereof was adsorbed on the membrane. Thereafter, the membrane was removed from the medium, and the membrane was immersed in a methylene blue-chloroform solution having a concentration of 0.003% by weight. After the immersion treatment, the film was taken out of the solution and air-dried, and the ability to decompose sodium alkylbenzenesulfonate was determined from the state of coloring with methylene blue.

[0012] The periphery of the colony of P. pseudo-alkaline genis No. 02A is lightly colored, while B. subtilus
In NIG 1121, the result that the periphery of the colony was colored with methylene blue was obtained.

Claims (1)

(57) [Claims] After culturing microorganisms in a culture medium containing a surfactant, a polymer film is put on the formed colony to adsorb the surfactant in the culture medium. A method for detecting surfactant-degrading microorganisms by the coloring state of a dried film thereof, wherein the microorganism is immersed in a solution of a coloring substance capable of forming a complex salt.