JP2003236555A - Method and agent for preventing slime adhesion - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high safety method for preventing slime adhesion effectively preventing the slime adhesion to surfaces of members in contact with water in a cooling water system or in an industrial water system such as a paper industry water system and an agent for preventing slime adhesion. <P>SOLUTION: The method for preventing slime adhesion is characterized in that an intercellular communication mediator of microorganisms is added to the water system and the agent for preventing slime adhesion is characterized in that it contains the intercellular communication mediator of microorganisms. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a slime adhesion preventing method and a slime adhesion preventing agent. More specifically, the present invention provides a highly safe slime adhesion preventing method capable of effectively preventing adhesion of slime to a member surface in contact with water in a cooling water system, an industrial water system such as a papermaking water system, etc. And a slime adhesion preventive agent.

[0002]

2. Description of the Related Art In an industrial water system such as a cooling water system or a papermaking water system, microorganisms adhere to a pipe wall or a vessel wall while generating a viscous substance and proliferate to form slime. When such slime is generated, in the cooling water system, the heat exchange efficiency is reduced, the surface of the pipe is corroded, and the pipe system is clogged. In the papermaking water system, slime adhering to the wall surface falls off, causing paper breakage and spots. Problems caused by slime adhesion are not limited to cooling water systems and papermaking water systems, but also industrial water systems including metalworking liquid systems, ultrapure water production systems, wastewater membrane treatment water systems, textile production water systems, and household water systems. , Agricultural water systems and other water systems. In order to solve such a problem, conventionally, a chemical substance which is a biocide is added to an aqueous system to kill a microorganism or suppress its growth. However, such chemical substances are becoming more concerned about their toxicity to the human body and seafood and their adverse effects on the environment. Therefore, a more safe slime adhesion preventing method and slime adhesion preventing agent have been demanded.

[0003]

DISCLOSURE OF THE INVENTION The present invention provides a safety system capable of effectively preventing adhesion of slime to the surface of a member in contact with water in an industrial water system such as a cooling water system or a papermaking water system. The purpose of the present invention is to provide a high slime adhesion preventing method and a slime adhesion preventing agent.

[0004]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that effective addition of slime can be achieved by adding a microbial intercellular signaling substance to an aqueous system. The present invention has been completed based on this finding. That is, the present invention provides (1) a method for preventing slime adhesion, which comprises adding an intercellular signaling substance of a microorganism to an aqueous system, and (2) an intercellular signaling substance is N-acylhomoserine lactone. The slime adhesion preventing method according to item 1, (3) the slime adhesion preventing method according to item 2, wherein the N-acylhomoserine lactone is N-octanoyl-L-homoserine lactone, and (4) intercellular communication of microorganisms. A slime anti-adhesive agent comprising a substance. Furthermore, as a preferred embodiment of the present invention,
(5) The slime adhesion-preventing agent according to item 4, wherein the intercellular signaling substance is N-acylhomoserine lactone;
(6) The slime adhesion-preventing agent according to item 5, wherein the N-acylhomoserine lactone is N-octanoyl-L-homoserine lactone.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION In the method for preventing slime adhesion of the present invention, an intercellular signaling substance of a microorganism is added to an aqueous system. The slime adhesion-preventing agent of the present invention contains a cell-cell signaling substance of a microorganism. Known intercellular signaling substances of microorganisms are N-acyl homoserine lactone in Gram-negative bacteria and peptidic pheromone-like substances in Gram-positive bacteria. These are substances produced by the cells of microorganisms and are substances that sense the concentration of cells when they are excreted outside the cells. Cells that sense intercellular signaling substances express various genes. Adjust. The intercellular signaling substance transmits information to cells of other microorganisms of the same or different species to control its trait. Traits controlled include pathogenicity, symbiotic initiation, motility, and biofilm maturation. In the present invention, as the intercellular signaling substance, a substance produced by a microbial cell can be used, or the same substance as a substance produced by a microbial cell can be synthesized and used. Examples of the intercellular signaling substance used in the present invention include N-
Examples thereof include acyl homoserine lactone, peptidic pheromone-like substance, and γ-butyrolactone.
Of these, N-acyl homoserine lactone has a good effect of preventing slime adhesion and is relatively easy to synthesize, and thus can be preferably used. N-acyl homoserine lactone can be produced by subjecting homoserine to cyclodehydration under acidic conditions and reacting with acid anhydride to acylate.

The N-acyl homoserine lactone used in the present invention is not particularly limited, and examples thereof include N-butanoyl-L-
Homoserine lactone, N-[(3R) -3-hydroxybutanoyl) -L-homoserine lactone, N-hexanoyl-L-homoserine lactone, N- (3-oxohexanoyl-L-homoserine lactone, N-octanoyl-
L-homoserine lactone, N- (3-oxooctanoyl) -L-homoserine lactone, N-decanoyl-L-
Homoserine lactone, N- (3-oxodecanoyl) -L
-Homoserine lactone, N- (3-oxododecanoyl)
-L-homoserine lactone and the like can be mentioned.
Among these, N-octanoyl-L-homoserine lactone having the structure represented by the formula [1] has an excellent slime adhesion-preventing effect and thus can be particularly preferably used.

[Chemical 1] In the method of the present invention, the concentration of the intercellular signaling substance of the microorganism added to the water system to be treated is not particularly limited, and can be appropriately selected depending on the strength of the slime generation tendency,
Usually, it is preferable that the concentration of the intercellular signaling substance in the target water is 0.005 to 10 mmol / L, and 0.0
It is more preferably 1 to 5 mmol / L. The intercellular signaling substance of the microorganism used in the present invention is a natural substance produced by cells, and has a very low bactericidal effect and growth inhibitory effect on bacteria, but has a high effect of inhibiting slime formation, and is effective in the water of bacteria. The formation of slime can be effectively prevented by preventing the adhesion of the slime to the surface of the member that is in contact therewith. In the slime adhesion preventing method and the slime adhesion preventing agent of the present invention, since the intercellular signal transmitting substance of the microorganism is used, there is no adverse effect on the human body and the environment, and the adhesion of slime can be safely prevented.

[0007]

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Example 1 A medium was prepared by dissolving 40 mg / L of D-glucose, 40 mg / L of polypeptone and 20 mg / L of sodium chloride in water obtained by treating water of Atsugi City with activated carbon and dechlorinating. 500 mL of this medium was placed in a 500 mL beaker, and N-octanoyl-L-homoserine lactone 113.5 mg (0.5 mmo)
l) was added and dissolved. This liquid has dimensions of 50 mm x 30 mm
Immerse a test piece made of stainless steel of × 1 mm, and use a magnetic stirrer and a rotor with a total length of 3 cm for about 30 mm.
The culture was carried out for 72 hours with stirring at 0 rpm. 72 hours later,
No slime adhered to the test piece. Example 2 Culturing was carried out for 72 hours in the same manner as in Example 1 except that the amount of N-octanoyl-L-homoserine lactone added to 500 mL of the medium was 11.4 mg (0.05 mmol).
After 72 hours, no slime had adhered to the test piece. Comparative Example 1 In the same manner as in Example 1 except that N-octanoyl-L-homoserine lactone was not added to 500 mL of the medium,
Incubation was carried out for 72 hours. After 72 hours, slime had adhered to the test piece. All slime adhering to the test piece was scraped off, centrifuged at 3,000 rpm for 10 minutes, and the wet volume was measured to determine the amount of slime adhering. The amount of slime adhered was 35 μL. Example 3 To the medium prepared in Example 1, a filtered material of river water was added as a microorganism source so that the turbidity was 50 degrees. 500 mL of the medium to which the filtrate of the river water was added was placed in a 500 mL beaker, and N-octanoyl-L-homoserine lactone 1 was added.
13.5 mg (1 mmol) was added and dissolved. A test piece made of stainless steel having a size of 50 mm × 30 mm × 1 mm was immersed in this liquid, and cultured for 72 hours while stirring at about 300 rpm using a magnetic stirrer and a rotor having a total length of 3 cm. After 72 hours, no slime had adhered to the test piece. Comparative Example 2 Culture was carried out for 72 hours in the same manner as in Example 3 except that N-octanoyl-L-homoserine lactone was not added to 500 mL of the medium to which the filtrate of river water was added.
After 72 hours, slime had adhered to the test piece.
Scrap all the slime adhering to the test piece,
Centrifugation was performed at 3,000 rpm for 10 minutes, and the wet volume was measured to determine the slime adhesion amount. The amount of slime adhered is 140
It was μL. The results of Examples 1 to 3 and Comparative Examples 1 and 2 are shown in Table 1.

[0008]

[Table 1]

As can be seen from Table 1, in the case of Comparative Example 1 in which no microbial source was added to the medium unless N-octanoyl-L-homoserine lactone was added, 35 μL of slime adhered and the microbial source was added to the medium. In Comparative Example 2, the adhered amount of slime is increased to 140 μL. On the other hand, when the microbial source was not added to the medium, 0.1 m of N-octanoyl-L-homoserine lactone was prepared as in Example 2.
Adhesion of slime can be completely prevented by adding mol / L, and even when microorganisms are added to the medium, 1 mmol / L of N-octanoyl-L-homoserine lactone is obtained as in Example 3. It is possible to completely prevent slime from adhering by adding. From this result, it is found that N-octanoyl-L-homoserine lactone has an excellent slime adhesion preventing effect.

[0010]

INDUSTRIAL APPLICABILITY According to the slime adhesion preventing method and slime adhesion preventing agent of the present invention, cell-to-cell information transfer of microorganisms having extremely low bactericidal effect and bacterial growth inhibiting effect on bacteria without using chemical substances that are biocides. By adding a substance to an aqueous system, it is possible to safely and effectively prevent slime from adhering to the surface of a member in contact with water in an industrial water system such as a cooling water system or a papermaking water system.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C02F 1/50 540 C02F 1/50 540C A01N 43/08 A01N 43/08 H D21H 17/07 D21H 17/07 21/04 21/04 F28F 19/01 F28F 19/00 501B (72) Inventor Saku Ikeda 6-32-3-901 F-term, Saijo Chuo, Higashihiroshima City, Hiroshima Prefecture (reference) 4H011 AA02 BA01 BB08 BC08 BC18 BC19 DA13 DD01 DH11 4L055 AG34 AG35 AH21 AH50 FA20 FA30

Claims (4)

[Claims] 1. A method for preventing adherence of slime, which comprises adding an intercellular signaling substance of a microorganism to an aqueous system. 2. The method for preventing slime adhesion according to claim 1, wherein the intercellular signaling substance is N-acyl homoserine lactone. 3. The method for preventing slime adhesion according to claim 2, wherein the N-acyl homoserine lactone is N-octanoyl-L-homoserine lactone. 4. A slime adhesion-preventing agent, which contains an intercellular signal transmitting substance of a microorganism.