JPH05245335A - Method for deodorizing organism - Google Patents

Abstract

PURPOSE:To remove hydrogen sulfide and methyl mercaptan and to enable proliferation and maintenance of odor removal activity even in the practical environment by bringing microorganisms belonging to Ochrobactrum genus into contact with odorous substance containing ions in a method for deodorizing the same. CONSTITUTION:Odorous substance containing hydrogen sulfide and methyl mercaptan or the like is generated in the process for decomposing and treating organic substance by microorganisms of drainage treatment in a sewage disposal plant. These are dangerous toxicant substance for organisms and severely regulated from being discharged in the circumferential environment. Therefor, the odorous substance is brought into contact with microorganisms belonging to Ochrobactrum genus, decomposed and removed. Further, since the microorganisms belonging to Ochrobactrum genus are subordinate nutritive microorganisms, culture is easy and the microorganisms are easily handled. Furthermore, hydrogen sulfide and methyl mercaptan are decomposed and removed even in the conditions of acidity caused in the process of deodorization, to say nothing of growth in a neutral region. The method is easy in management and practical.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel biological deodorizing method, and more particularly to the genus Ochrobaculum.
By using the action of microorganisms belonging to the group (trum ), it decomposes and removes sulfur-containing odorous substances such as hydrogen sulfide and methyl mercaptan, which are the main components of malodorous gas generated from human waste or sewage treatment plants, livestock and factories such as food It relates to a deodorizing method for

[0002]

2. Description of the Related Art Currently, in the treatment of wastewater in a human waste / sewage treatment plant or a livestock factory, there is usually a process of decomposing organic substances by microorganisms. Generates sulfur-containing odorous substances. In particular, hydrogen sulfide is a toxic substance which not only gives offensive odor but is dangerous to the living body, and hydrogen sulfide, methyl mercaptan and the like are strictly regulated to be released into the surrounding environment.

Therefore, in such conventional treatment plants and factories, these odors have been removed by various deodorizing devices utilizing the neutralization or oxidation reaction with chemical substances and the adsorption action of activated carbon or the like. However, due to problems such as the operating cost of the deodorizing device, a biological deodorizing device utilizing the degrading action of microorganisms has been attracting attention as a deodorizing device having a lower operating cost.

Among them, microorganisms belonging to the genus Thiobacillus and those belonging to the genus Hyphomicrobium are known as microorganisms having an action of decomposing sulfur-containing odorous substances such as hydrogen sulfide. .. However, these microorganisms, for example, microorganisms belonging to the genus Thiobacillus can remove hydrogen sulfide but not methylmercaptan,
It is said that it is difficult for one microorganism to remove multiple sulfur-containing odorants. In addition, due to the oxidizing substances such as sulfuric acid generated from sulfur-containing odor substances by the action of such microorganisms, when the environment in which the microorganisms grow is under acidic conditions, some microorganisms that grow even in a highly acidic environment are exceptions, It is said that the ability to remove sulfur-containing odorous substances is reduced in ordinary microorganisms having an active region near neutrality. Furthermore, many of such conventional microorganisms have strong autotrophic properties, and their growth is impaired in a device for practical use where a large amount of organic substances are mixed, or the growth rate of bacteria is slowed down. There was a problem.

[0005]

Means for Solving the Problems In the biological deodorization method for sulfur-containing odorous substances, the present inventors can remove hydrogen sulfide and methyl mercaptan in a wide range from neutral to acidic, and even in a practical environment. As a result of conducting a search and a study for a microorganism that can grow and maintain the odor eliminating activity, it was found for the first time that a specific microorganism can solve such a problem, and the present invention has been completed.

[0006] That is, the gist of the present invention resides in a method for deodorizing a sulfur-containing odor substance, which comprises contacting a microorganism belonging to the genus Ochrobactrum with a sulfur-containing odor substance. Hereinafter, the present invention will be described in detail.

In the present invention, the Ochrobactrum ( Ochr
Microorganisms belonging to the genus Obactrum ) are used. Such microorganisms include Ochrobactram ( Ochroba).
There is no particular limitation as long as it belongs to the genus ctrum ) and has the ability to decompose and remove sulfur-containing odorous substances. Specifically, the present inventors have isolated Ochrobactrum sp. ( Ochrobac ) from unaged compost.
trum sp. ) MJ-3 strain (hereinafter sometimes abbreviated as "this strain" or "MJ-3 bacterium").
This strain has been deposited at the Institute of Microbial Science and Technology of the Agency of Industrial Science and Technology as Micromachine Research Institute No. 12802 (FERM P-12802). The mycological properties of this strain are as follows.

[0008]

[Table 1] 1. Morphological properties ○ Characteristics of colonies after culturing on tryptosome agar medium at 30 ° C for 24 hours 1) Outer shape: circular shape 2) Surface ridge: semi-lens shape 3) Surface shape: smooth 4) Gloss: dull light 5) Color tone: Light blue 6) Transparency: Opaque 7) Edge: Full edge 8) Viscosity: Yes ○ Morphological properties after incubation on tryptosome agar at 30 ° C for 24 hours 1) Cell morphology: Rod-like 0.4 μm × 1 ~ 1.
7 μm 2) Polymorphism: None 3) Motility: Yes, with periflagellates 4) Sporulation: None 5) Gram stain: Negative 6) Anti-acidic: Negative 2. Physiological properties 1) Growth under anaerobic conditions: Negative 2) Growth in air: Positive 3) Catalase: Positive 4) Oxidase: Positive 5) OF test: O 6) Hydrolysis of gelatin: Negative 7) Litmus milk: Acidic, no peptonization, no coagulation 8) Nitrate reduction: Positive 9) VP test: Positive 10) Indole formation: Negative 11) Hydrogen sulfide formation: Negative 12) Starch hydrolysis: Negative 13) Quenching Utilization of acid: Positive (on Christensen medium) 14) Urease: Negative 15) Hydrolysis of casein: Positive 16) Utilization of inorganic nitrogen source NaNO ₃ : Negative (NH ₄ ) ₂ SO ₄ : Positive 17) Dye formation: None 18) Growth temperature range: 15 to 40 ° C. Growth pH: pH 3 to 11 19) DNase activity: Negative 20) Degradation of Tween 80: Negative 21) Degradation of esculin: Negative 22) Hydrolysis of arginine: Negative 23) β-Galactosidase: Negative 24) Utilization of N-acetylglucosamine: Positive 25) Generation of acid from carbon source

[0009]

[Table 2]

26) Utilization of organic acid

[0011]

[Table 3]

[0012]

[Table 4] 3. Chemotaxonomic properties 1) GC content in DNA (Tm method): 57 mol% 2) Ubiquinone: Q-10

4. Taxonomic consideration ○ Identification of genus level This strain (MJ-3 strain) shows 1) Gram-negative,
2) shows absolute aerobic property, 3) has morphological and physiological properties such as having periflagellates, and chemotaxonomic properties 4)
5) Having ubiquinone Q-10 as an isoprenoid quinone, 5) It has a feature that the GC content in DNA is 57%. Ber for genus with these characteristics
gay's Annual of System
ic Bacteriology Volume 1 and Inter
national Journal of System
atic Bacterology Volume 38, 406
-Searching based on page 416 (1988),
Rhizobium genus known as plant parasitic fungus, Ag
It has been suggested that they are closely related to the genus Ractobacterium and the genus Ochrobacterium that is mainly isolated from human clinical specimens.

Then, when the present strain was compared with these genera, as shown in the following table, Ochrobacterium
This strain (MJ-3 strain) was well matched with the characteristics of the genus.
Was identified as the genus Ochrobacterium .

[0015]

[Table 5] Species-level identification Ochrobac currently belongs to the genus Ochrobactrum
Although one species of T. anthropi is known, this strain (MJ-3 strain) has a point that there is a difference in utilization of sugars such as trehalose and inositol, presence or absence of urease activity, etc., and thus Ochrobactraum sp. MJ
It was identified as -3.

In the biological deodorizing method of the present invention, the sulfur-containing odorous substance is treated with Ochrobactrum .
Contact with microorganisms belonging to the genus. Examples of the contact method include a method of directly blowing a bad odor into the culture solution, a method of contacting with a gas-liquid contact tower, and a method of aerating an odor substance by adhering and containing microorganisms in a filling tank. Examples of the sulfur-containing odorous substance include hydrogen sulfide, methyl mercaptan, dimethyl sulfoxide, methyl sulfide, methyl disulfide, etc., but it is particularly important in the present invention to decompose and remove hydrogen sulfide and / or methyl mercaptan. ..

Ochrobactrum
The nutrients required for the growth of microorganisms belonging to the genus ( um ) are not particularly limited, and those normally used for culturing microorganisms can be used. For example, as the carbon source, glucose, sucrose, fructose, glycerol, sorbitol, molasses, sugars such as starch hydrolysate, acetic acid, organic acids such as fumaric acid, etc., the nitrogen source,
Nitrate, ammonium salt, corn steep liquor, yeast extract, meat extract, yeast powder, soybean hydrolyzate, cottonseed flour, polypeptone, benton, etc., as inorganic salts, calcium phosphate, sodium phosphate, magnesium sulfate, sodium chloride However, in the present invention, by adding sodium thiosulfate to the culture solution, only microorganisms having the activity of decomposing and removing sulfur-containing odorous substances can be selected. The amount of sodium thiosulfate added is 0.1 to 5 per culture solution.
It is preferably in the weight%. It is also desirable to add inorganic salts such as iron ions, cobalt ions, and copper ions to the culture solution, if necessary.

The culture temperature is 10 to 40 ° C., preferably 25
~ 37 ° C, pH 3.0 ~ 11.0, preferably 5.0
At about 7.0, the bacterium grows sufficiently by culturing for about 2 to 24 hours. At that time, the culture is performed aerobically.
In practicing the present invention, a support made of a suitable organic or inorganic material is attached to Ochrobactrum ( Ochrob).
The microorganisms belonging to the genus actrum ) are attached and contained,
It is also possible to ventilate the sulfur-containing odorous substances mentioned above.

[0019]

EFFECT OF THE INVENTION Ochrobactrum
Since a microorganism belonging to the genus rum ) is a heterotrophic microorganism, it has been conventionally known that it has the ability to decompose and remove hydrogen sulfide ( Thioba).
It is a microorganism that is easier to culture and easier to handle than a microorganism belonging to the genus ( Cillus ). Furthermore, it is possible to decompose and remove hydrogen sulfide and methyl mercaptan even under acidic conditions that occur during the deodorizing process, let alone growth in the neutral region. A biological deodorizing method suitable for practical use is provided.

[0020]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the invention is not limited thereto unless it exceeds the gist. Example 1 MJ-3 bacteria were shake-cultured for 12 hours at 210 rpm in a tryptosoya medium supplemented with 1% sodium thiosulfate, and centrifuged (3000 rpm) to recover the bacterial cells.
The obtained cells were mixed with 0.01M sodium phosphate buffer (p
After washing with H7.2), the cells were suspended in phosphate buffered saline (hereinafter abbreviated as "PBS") to give a bacterial suspension.

25 ml of this bacterial suspension was filled in a 50 ml glass vial, and hydrogen sulfide of about 100 ppm was bubbled through the liquid at 100 ml / min for about 5 minutes to replace the gas phase in the vial with hydrogen sulfide. .. Gas chromatography (Shimadzu Corporation, GC-14A) was used to examine the change over time in the hydrogen sulfide concentration in the gas phase while shaking this vial while keeping it warm at 30 ° C.
It was measured at. The results are shown in Figure 1. From this, it was suggested that MJ-3 bacterium has an excellent deodorizing effect.

Examples 2 to 5 MJ-3 bacteria were cultivated in a tryptosoya medium supplemented with 1% sodium thiosulfate in the same manner as in Example 1 to recover the cells. The obtained bacterial cells were washed with 0.01 M sodium phosphate buffer (pH 7.2) or diluted sulfuric acid (pH 3.0) and resuspended in each solution to give a bacterial suspension.

Next, the time-dependent changes in the respective gas concentrations in the gas phase were measured in the same manner except that hydrogen sulfide of about 100 ppm or methyl mercaptan of about 20 ppm was used as the ventilation gas. The results are shown in FIGS. From this, MJ
It is clear that the No. 3 bacterium can decompose and remove hydrogen sulfide and methyl mercaptan under both acidic and neutral conditions.

[Brief description of drawings]

FIG. 1 is a drawing showing changes over time in hydrogen sulfide concentration in the vapor phase of a glass vial. In the figure, △ is MJ-3 bacterium cultured with addition of sodium thiosulfate, ◇ is MJ-3 bacterium cultured without addition of sodium thiosulfate, and □ is gas phase concentration change when only PBS is filled. Respectively.

FIG. 2 is a drawing showing hydrogen sulfide removal characteristics under neutral conditions (pH 7.2). In the figure, + represents the removal characteristics of MJ-3 bacteria, and □ represents the control (PBS).

FIG. 3 is a drawing showing hydrogen sulfide removal characteristics under neutral (pH 3.0) conditions. In the figure, + represents the removal characteristics of MJ-3 bacteria, and □ represents the control (PBS).

FIG. 4 is a drawing showing the removal characteristics of methyl mercaptan under neutral conditions (pH 7.2). In the figure, + is MJ
-3 represents the removal characteristics of No. 3 bacteria, and □ represents the control (PBS).

FIG. 5 is a drawing showing the removal characteristics of methyl mercaptan under acidic conditions (pH 3.0). In the figure, + is MJ
-3 represents the removal characteristics of No. 3 bacteria, and □ represents the control (PBS).

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Reiko Sashida 1000 Kamoshida-cho, Midori-ku, Yokohama, Kanagawa Sanryoh Kasei Co., Ltd. (72) Takashi Mikawa 1000 Kamoshida-cho, Midori-ku, Yokohama, Kanagawa Prefecture Ryokasei Co., Ltd.

Claims (3)

[Claims] 1. A method for deodorizing a sulfur-containing odor substance, which comprises contacting a microorganism belonging to the genus Ochrobactrum with a sulfur-containing odor substance. 2. The method according to claim 1, wherein the sulfur-containing odorous substance is hydrogen sulfide / or methyl mercaptan. 3. The method according to claim 1, wherein the microorganism belonging to the genus Ochrobactrum is cultured in a medium containing sodium thiosulfate.