JP2002125659A - New microorganism and method for treating drain - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new microorganism which can aerobically degrade liquid fatty oils, solid fats, other organic substances, and the like over a wide temperature range, and to provide a method for treating drain, which uses the new microorganism. SOLUTION: This method for treating the drain, characterized by bringing the drain into contact with Burkholderia cepacia AIK strain (FERM BP-7308).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel microorganism and a method for treating wastewater, and its object is to aerobicly decompose liquid and solid oils and fats and other organic substances over a wide temperature range. An object of the present invention is to provide a novel microorganism and a method for treating wastewater using the novel microorganism.

[0002]

2. Description of the Related Art Wastewater discharged from food factories, restaurants, general households and the like often contains a large amount of animal and vegetable oils and fats. Normally, fats and oils contained in wastewater are separated and removed by a natural levitation device or a pressure levitation device.
With such a physical or chemical separation and removal method, fats and oils in the wastewater cannot be completely removed, and the wastewater containing the fats and oils is supplied to a decomposition tank, and suspended organisms such as an activated sludge method are used. At present, it is decomposed and removed by a biological treatment method such as a biofilm method such as a rotating biological contact method.

[0003] As a biological treatment method of wastewater containing oils and fats, for example, Japanese Patent Application Laid-Open No. 8-197986 discloses a method.
A method for decomposing animal and plant fats and oils contained in wastewater using a specific strain belonging to the genus Pseudomonas is disclosed. Japanese Patent Application Laid-Open No. 9-85283 discloses a method of treating wastewater using bacteria belonging to the genus Burkholderia and capable of decomposing animal and vegetable fats and oils at high temperatures. Further, JP-A-11-47798 discloses a method of decomposing animal and plant fats and oils contained in wastewater using a specific strain belonging to the genus Pseudomonas.

[0004]

However, the above-described conventional method for treating wastewater has the following problems. The fat-decomposing bacteria used in the conventional wastewater treatment method may be in a specific temperature range, for example, in Japanese Patent Application Laid-Open No.
About 40 ° C. in the case of the bacteria disclosed in US Pat.
The fats and oils can be decomposed in the above temperature range.
However, it is known that the temperature in the decomposition tank in which biological decomposition is performed undergoes a large temperature change depending on weather conditions, seasons, installation locations, and the like. For this reason, it was difficult for the conventional fat-and-oil-degrading bacteria to always exhibit high resolution in a decomposition tank in which a drastic temperature change occurs. As a result, the quality of the treated water treated and discharged in the decomposition tank is not always constant, and the fats and oils may be discharged without being completely decomposed. The fat-decomposing bacteria used in the above-described wastewater treatment method can decompose liquid fats and oils, but it has been difficult to similarly decompose solid fats and oils. When the wastewater contains a large amount of solid fats and oils, the quality of the treated water is deteriorated, and anaerobic bacteria are generated to generate a bad smell.

[0005] As a result of intensive studies in view of the above problems, Burkholderia cepacia (Burkholderia cepacia) has been developed.
It has been found that one strain belonging to ia) has a high resolution for liquid and solid fats and oils over a wide temperature range, and the present invention has been completed.

[0006]

That is, the present invention according to claim 1 is directed to a Burkholderia cepacia AIK strain (FERM BP-7308) having fat and oil decomposability.
About. The invention according to claim 2 relates to a method for treating wastewater, wherein the wastewater is brought into contact with microorganisms belonging to the genus Burkholderia and capable of mainly decomposing fats and oils. The invention according to claim 3 relates to the method for treating wastewater according to claim 2, wherein the microorganism belonging to the genus Burkholderia is one of a group of microorganisms constituting activated sludge. . The invention according to claim 4 provides the genus Burkholderia
Microorganisms belonging to Burkholderia cepacia (Burk
4. The method for treating wastewater according to claim 2, wherein the strain is a holderia cepacia) AIK strain (FERM BP-7308).

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a novel microorganism according to the present invention will be described. The novel microorganism according to the present invention is a bacterium obtained by sampling soil of Ishigaki Island in Okinawa Prefecture and performing screening, and has excellent resolution for fats and oils in a wide temperature range, as well as fatty acids, proteins, and carbohydrates. It also has the resolution for organic substances such as sugars. Hereinafter, the novel microorganism separation method according to the present invention will be described. First, 12 samples from Ishigaki Island, Okinawa
Six samples of soil were cultured in the medium. Only samples that grew well on the medium were cultured on the medium. Hereinafter, similarly, only the samples with good growth were cultured in the following medium in order to finally obtain six samples. Nutrient medium supplemented with 5% olive oil (composition; Table 1 below)
The yeast extract and casamino acid were each added to a medium prepared by dissolving the composition of the above in purified water to make 1000.0 ml, and 1.0 g / L of each was added). A nutrient medium supplemented with 10% olive oil. A nutrient medium supplemented with 10% olive oil. The planting was carried out three times. Actual drainage. A nutrient medium containing 2% lard. A nutrient medium containing 2% salad oil. A nutrient medium containing 10% lard. A nutrient medium containing 1% salad oil. The planting was carried out three times. A nutrient medium containing 2% beef tallow.

The lipase activity and the amount of fat and oil decomposed in the wastewater containing fat and oil were measured for the six samples separated by the above method, and the sample with the best results was obtained. Thus, Burkholderia acepacia AIK strain was isolated from the soil of Ishigaki Island, Okinawa Prefecture.

Hereinafter, the bacteriological properties of the isolated Burkholderia cepacia AIK strain will be described. The test and classification method for mycological properties is described in E. Yabuuchi et al., Microbiology and Immunology,
36 , 1251-1275, 1992.

(1) Morphological properties (a) Shape and size of cells; 1.0-1.5 μm long and 0.8 μm wide bacilli (b) Gram stainability;-(c) Spores;-( d) Motility; + (e) Colony morphology; circular, peripheral wavy, low convex, surface stripes, yellow (water-soluble pigment) (f) Flagella adhesion;

(2) Cultural properties (a) Broth liquid culture; surface film formation (b) Litmus milk;

(2) Physiological properties (a) catalase; + (b) oxidase; + (c) O / F test;-(d) nitrate reduction;-(e) indole production;-(f) glucose acidification -(G) arginine dihydrolase;-(h) urease;-(i) esculin hydrolysis; + (j) gelatin hydrolysis;-(k) β-galactosidase;-(l) denitrification reaction;-(m ) MR test; + (n) VP test; - (o) H ₂ S production; - (p) starch hydrolysis; - (q) use of citric acid; Koser / +, Christensen / + (r) inorganic nitrogen sources Use of NaNO ₃ / +, (NH ₄ ) ₂
SO ₄ / + (s) pigment formation; water-soluble yellow pigment (t) anaerobic growth; − (u) degradation of Tween 80; + (v) degradation of poly-β-hydroxybutyric acid; − (w) substrate assimilation ability Glucose, L-arabinose, D-mannose, D-mannitol, N-acetyl-D-glucosamine, potassium gluconate, n-capric acid, adipic acid, DL-malic acid, sodium citrate, phenyl acetate . Maltose is not assimilated. (x) generation of acid from sugars; glucose, xylose,
Mannitol, lactose and maltose produce acid. (y) Production of acid and gas by OF medium (acid / gas);
Arabinose (-/-), D-xylose (+/-),
D-glucose (+/-), D-mannose (-/
-), D-fructose (-/-), D-galactose (+/-), maltose (+/-), sucrose (+/-), lactose (+/-), trehalose (+
_w /-), D-sorbitol (-/-), D-mannitol (+/-), inositol (-/-), glycerin (-/-), starch (-/-).

[0013] From the mycological properties and the description in the above literature, the novel microorganism according to the present invention is a gram-negative bacillus having motility, which shows both catalase and oxidase negative and produces acid from glucose. It was identified as a microorganism belonging to the genus Burkholderia. Furthermore, the novel microorganism according to the present invention produces an acid from glucose, xylose, mannitol, lactose, and maltose, and is negative for arginine dihydrolase. Therefore, it is determined that the microorganism belongs to Burkholderia cepacia, The strain was designated as Burkholderia cepacia AIK strain. Burkholderia cepacia AI
The K strain was deposited on September 25, 2000 with the Research Institute of Biotechnology and Industrial Technology, Ministry of International Trade and Industry of Japan, under the microorganism deposit number FERM BP-
Deposited as 7308.

Burkholderia cepacia
ia cepacia) The medium used to culture the AIK strain is not particularly limited, and a usual liquid medium or solid medium can be used. The nutrient source of the medium may be any nutrient source necessary for the growth of bacteria, such as a carbon source, a nitrogen source, and inorganic salts. Examples of the carbon source include glucose, sucrose, molasses, and starch. As the nitrogen source, any of an organic nitrogen source and an inorganic nitrogen source can be used. As the organic nitrogen source, peptone, yeast extract, malt extract, meat extract,
Examples of the inorganic nitrogen source include soybean decomposition products and urea, and ammonium nitrate and sodium nitrate.
As inorganic salts, phosphates, magnesium sulfate, potassium, sodium, calcium, copper, manganese, zinc,
Examples thereof include calcium chloride and ferrous sulfate.

The pH of the medium is 2.0 to 12.0, preferably 5.0 to 8.0, more preferably 6.0 to 8.0, and is preferably 7.0 to 8.0. Most preferred. The temperature of the culture medium was Burkholderia cepacia (Burk
holderia cepacia) Any temperature can be used as long as the AIK strain can grow, specifically, 15 to 45 ° C, preferably 15 to 45 ° C.
The temperature is 40 ° C, more preferably 20 to 35 ° C.

[0016] Burkholderia cepacia
ia cepacia) AIK strain is capable of suitably decomposing fats and oils. Burkholderia Burkholderia
cepacia) The temperature at which the fats and oils of the AIK strain are decomposed is not particularly limited, but is 15 to 45 ° C, preferably 15 to 40 ° C.
° C, more preferably 20-35 ° C. Since the temperature in the cracking tank usually fluctuates within a range of about 20 to 35 ° C., Burkholderia cepacia (Burkholderia c.
epacia) AIK strains can exhibit extremely good resolution in the digestion tank. Further, Burkholderia cepacia AIK strain is capable of suitably decomposing any of animal fats and oils and vegetable fats and oils, and furthermore, fats and oils which are liquid at normal temperature such as salad oil, olive oil, sesame oil and the like. Without being limited to
Solid fats and oils at room temperature, such as lard, beef tallow, and coconut oil, can also be suitably decomposed. Moreover, as will be apparent from the examples described later, it is possible to decompose to an extremely low concentration in a short time. Also, Burke Holdelia Sepacia (Bu
rkholderia cepacia) The AIK strain is capable of degrading fats and oils even in the presence of a surfactant. That is,
Even the actual fats and oils in the wastewater mixed with the detergent can be decomposed. In addition, Burkholderia cepacia AIK strain can suitably degrade fatty acids such as lauric acid, myristic acid, and oleic acid, and organic substances such as proteins, carbohydrates, and saccharides, in addition to fats and oils. The temperature at which these organic substances are decomposed is not particularly limited, but is 15 to 4 as in the case of fats and oils.
5 ° C, preferably 15 to 40 ° C, more preferably 20 to
35 ° C.

Next, a method for treating wastewater according to the present invention will be described. The method for treating wastewater according to the present invention is characterized by bringing bacteria belonging to the genus Burkholderia into contact with wastewater. The bacterium belonging to the genus Burkholderia is not particularly limited as long as it is a bacterium capable of mainly decomposing fats and oils, but is preferably a bacterium capable of decomposing fats and oils over a wide temperature range. . The reason for this is that the temperature in the decomposition tank is not always constant, but fluctuates drastically depending on various conditions such as weather conditions, seasons, and installation locations. (See FIG. 3. FIG. 3 is a graph showing the monthly average temperature change in a certain decomposition tank.) Since the temperature fluctuation in this decomposition tank affects the resolution of microorganisms, The quality of the treated water decomposed in the decomposition tank is not stable, and during the period when the degradation ability of microorganisms is reduced, the fats and oils are not completely decomposed and may be mixed into the treated water and discharged. there were. (See FIG. 4. FIG.
It is the graph which showed the amount of the n-hexane extract contained in the process water discharged | emitted by decomposing | disassembling in a certain decomposition tank, ie, the average of fats and oils content. That is, at least the temperature range in the decomposition tank, specifically 15 to 40 ° C., preferably 2
By using bacteria capable of exhibiting high resolution over substantially the entire temperature range of 0 to 35 ° C., even if a temperature change occurs in the decomposition tank, the decomposition ability is not reduced, and a stable treatment is always performed. Because it can be done. In addition, Burkholderia used
The bacterium belonging to the genus eria) is preferably a bacterium that can suitably degrade not only liquid fats and oils at room temperature but also solid fats and oils at room temperature. The reason for this is that the wastewater flowing into the decomposition tank contains not only oils and fats that are liquid at room temperature but also oils and fats that are solid at room temperature. The bacterium belonging to the genus Burkholderia used is preferably a bacterium that can degrade not only fats and oils but also organic substances other than fats and oils, such as fatty acids, proteins, carbohydrates, and saccharides. The reason for this is that the BOD (biochemical oxygen demand) and COD (chemical oxygen demand) of the wastewater can be reduced by decomposing organic substances other than fats and oils. Bacteria that meet the above conditions include Burkholderia cepacia.
eria cepacia) AIK strain (FERM BP-7308) and the like.

The method for treating wastewater according to the present invention is a biofilm method such as a floating organism method such as an activated sludge method, a rotating organism contact method, a sprinkling filter method, a contact oxidation method and an aerobic filter method, or an immobilization method. Any of the microbial methods may be used. That is, bacteria belonging to the genus Burkholderia (Burkholderia), even if used as a kind of microorganisms constituting the activated sludge,
Further, it may be used as a kind of a group of microorganisms constituting a biofilm fixed to the surface of a disk or the like, or may be used as a kind of a group of microorganisms carried on a carrier.

The method for treating wastewater according to the present invention can suitably decompose liquid and solid fats and oils without being affected by temperature changes in the decomposition tank. It is possible to decompose fats and oils regardless of conditions. In addition, since the growth of anaerobic organisms can be suppressed to prevent the generation of offensive odors, and the high resolution can always be exhibited, the quality of the treated water discharged from the decomposition tank is kept almost constant. Can be maintained.

[0020]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to the following examples. (Samples of Examples and Comparative Examples) Burkholderia cepacia AIK strain was used as a sample of Example 1. In addition, Super H bacteria (trade name, Kondo FR)
(Company P) was used as the sample of Comparative Example 1, and activated sludge (cultured at the Institute of Biotechnology and Industrial Technology) was used as the sample of Comparative Example 2.

(Test Example 1; Decomposition of Lard) A medium prepared by dissolving the composition shown in Table 1 in purified water to make 1000.0 ml was mixed with 500 ppm of lard and 10 parts of detergent.
After sterilization by adding ppm, 16 rpm at a speed of 150 rpm.
Shake for hours to obtain synthetic wastewater. In addition, this synthetic wastewater was confirmed to have substantially the same properties as actual wastewater by a property comparison test. Next, after washing 20 ml (containing 0.06 g of dry cells of the bacterial cells) of the sample pre-cultured in the LB medium with the prepared synthetic wastewater, the synthetic wastewater 200 m
and shaking culture at 30 ° C. and 150 rpm.
Finally, the concentration of lard in the synthetic wastewater after a predetermined time had elapsed was measured. The measurement was performed by measuring the concentration of the n-hexane extract in the synthetic wastewater after a predetermined time as an extraction efficiency of 98.6% (three controls were prepared and separately calculated). For each measurement, three samples were prepared, and the average value was determined. The same experiment was performed using the sample of Comparative Example 1. Table 2 shows the results.

[0022]

[Table 1]

[0023]

[Table 2]

As shown in Table 2, the novel microorganism according to the present invention, Burkholderia cepacia,
eria cepacia) The AIK strain shows remarkably excellent resolution as compared with Comparative Example 1, and the solid fats and oils are reduced to about 1/4, 9 in 4 hours.
It can be decomposed to a concentration of about 1/10 in time, and after 24 hours, it can be almost completely decomposed.

(Test Example 2: Decomposition of salad oil) In a medium similar to the medium used in Test Example 1, 500 ppm of salad oil,
After adding 10 ppm of detergent and sterilizing, the speed was 150 rpm.
m for 16 hours to obtain synthetic wastewater. In addition, this synthetic wastewater was confirmed to have substantially the same properties as actual wastewater by a property comparison test. Next, 20 ml of the sample (containing 0.06 g of dry cells) of the example pre-cultured in the LB medium was washed with the prepared synthetic wastewater, added to 200 ml of the synthetic wastewater, and shaken at 30 ° C. and 150 rpm. Cultured. Finally, the concentration of the salad oil contained in the synthetic wastewater after a predetermined time had elapsed was measured. The measurement was performed by measuring the concentration of the n-hexane extract in the synthetic wastewater after a predetermined time as an extraction efficiency of 97.5% (three controls were prepared and separately calculated). For each measurement, three samples were prepared, and the average value was determined. The same experiment was performed using the samples of Comparative Example 1 and Comparative Example 2. Table 3 shows the results.

[0026]

[Table 3]

As shown in Table 3, the novel microorganism according to the present invention, Burkholderia cepacia,
eria cepacia) The AIK strain shows remarkably superior resolution as compared with Comparative Examples 1 and 2, and the liquid oils and fats are reduced to about 1 /
It can be decomposed to about 1/10 concentration in 7 and 9 hours, and can be almost completely decomposed after 24 hours.

Test Example 3 Temperature Dependency in Decomposition of Fats and Oils
m, sterilization by adding 10 ppm of detergent,
The mixture was shaken at rpm for 16 hours to obtain synthetic wastewater. Next, LB
20 ml of the sample of the example pre-cultured in the medium (dry weight: 0.
After washing with the synthetic wastewater prepared above, it was added to 200 ml of the synthetic wastewater, and 1 hour at a predetermined temperature.
Shaking culture was performed at 50 rpm for 4 hours. Finally, the decomposition rate of the salad oil was measured. The measurement was carried out by measuring the concentration of the n-hexane extract in the synthetic wastewater as the extraction efficiency of 97.5% (three controls were prepared and separately calculated). For each measurement, three samples were prepared, and the average value was determined. In addition, it measured by the same experimental method using the sample of Comparative Example 1. The results are shown in Table 4 and FIG. Note that the solid line in FIG. 1 is a graph showing the result of Example, and the broken line is a graph showing the result of Comparative Example 1.

[0029]

[Table 4]

As shown in Table 4 and FIG. 1, the Burkholderia cepacia AIK strain, which is a novel microorganism of the present invention, can be used at a low temperature of 15 ° C. or lower and at a high temperature of 40 ° C. or higher. It can also be seen that this has the resolution of fats and oils. In addition, about 20-
It can be seen that in the temperature range of 35 ° C., an extremely excellent resolution of 80% or more can always be exhibited.

Test Example 4 Influence of Variation of Inoculation Amount on Decomposition of Salad Oil To a medium having the same composition as in Test Example 1, 500 ppm of salad oil and 10 ppm of detergent were added to obtain a sterilized synthetic wastewater. Next, after washing a predetermined amount of the sample of the example (containing 3.0 g of dry cells in 1 liter of medium) with the synthetic wastewater prepared as above, the sample was added to 200 ml of synthetic wastewater. And shaking culture at 150 rpm at 30 ° C for 4 hours. Finally, the concentration of salad oil in the synthetic wastewater was measured. The measurement method is to determine the concentration of the n-hexane extract in the synthetic waste water after a predetermined time has elapsed, and to determine the extraction efficiency 97.5.
% (Three controls were prepared and calculated separately). For each measurement, three samples were prepared, and the average value was determined. Table 5 shows the results.

[0032]

[Table 5]

As shown in Table 5, the novel microorganism according to the present invention, Burkholderia cepacia,
epacia) The AIK strain can degrade oils and fats in a short time even with a very small amount of addition.

(Test Example 5: Decomposition of fats and oils in actual wastewater) After collecting actual wastewater, it was sterilized and filtered. still,
The amount of the n-hexane extract in the wastewater was 15 ppm. Next, the amount of the n-hexane extract of the wastewater was reduced to 50.
After adding salad oil to be 0 ppm, the mixture was shaken for 16 hours. 20 m sample of the example pre-cultured in LB medium
1 (containing 0.06 g of dry cells) was washed with the adjusted wastewater, and added to 200 ml of the wastewater.
Shaking culture was performed at 150 ° C. and 150 rpm. Finally, the concentration of the n-hexane extract contained in the wastewater after a predetermined time had elapsed was measured. For each measurement, three samples were prepared, and the average value was determined. Table 6 shows the results.

[0035]

[Table 6]

As shown in Table 6, the novel microorganism according to the present invention, Burkholderia cepacia,
epacia) It can be seen that the AIK strain can exhibit substantially the same ability in synthetic wastewater (see the results of the examples shown in Table 3 where similar experiments were performed using synthetic wastewater) and in actual wastewater. .

(Test Example 6: Influence of Peptone on Decomposition of Salad Oil) A medium having the same composition as in Test Example 1 was prepared by adding 500 ppm of salad oil, 10 ppm of detergent, and 0.1% of peptone.
Was added and sterilized, followed by shaking at a speed of 150 rpm for 16 hours to obtain synthetic wastewater. Next, the concentration of the n-hexane extract in the synthetic wastewater after the lapse of a predetermined time was measured in exactly the same manner as in Test Example 2 described above. Table 7 shows the results.

[0038]

[Table 7]

As shown in Table 7, the novel microorganism according to the present invention, Burkholderia cepacia,
eria cepacia) Even if peptone, which is considered to be more easily decomposed than fats and oils, is present in the AIK strain, it is not present (Example shown in Table 3 in which the same experiment was carried out without adding peptone). ).

Test Example 7 Effect of pH Change on Salad Oil Decomposition A 0.5N medium was added to a medium having the same composition as in Test Example 1.
The pH of the medium was adjusted as shown in Table 8 by adjusting the pH with a pH meter using HCl and 0.5N NaOH. Next, add 50 salad oils to each medium.
After sterilization by adding 0 ppm and 10 ppm of a detergent, the mixture was shaken at a speed of 150 rpm for 16 hours to obtain synthetic wastewater. Next, 20 ml of the sample (containing 0.06 g of dry cells) containing the cells of the example pre-cultured in the LB medium was washed with each of the prepared synthetic wastewaters, and then added to 200 ml of the synthetic wastewaters. For 4 hours with shaking. Finally, the concentration of salad oil contained in the synthetic wastewater was measured.
The measurement was performed by measuring the concentration of the n-hexane extract in the synthetic wastewater after a predetermined time as an extraction efficiency of 97.5% (three controls were prepared and separately calculated). For each measurement, three samples were prepared, and the average value was determined. The results are shown in Table 8 and FIG.

[0041]

[Table 8]

As shown in Table 8 and FIG. 2, the Burkholderia cepacia AIK strain, which is a novel microorganism according to the present invention, can degrade fats and oils in a wide pH range. In particular, it can be seen that when the pH is 7.0 to 8.0, extremely excellent resolution is exhibited.

(Test Example 8: Decomposition of salad oil in tap water) After 500 ppm of salad oil was added to tap water and sterilized, it was shaken at a speed of 150 rpm for 16 hours to obtain synthetic waste water. Next, 20 m of the sample of the example pre-cultured in the LB medium was used.
1 (containing 0.06 g of dry cells) was washed with physiological saline, added to 200 ml of the synthetic wastewater prepared above, and cultured with shaking at 30 ° C. and 150 rpm for 24 hours. Finally, the concentration of salad oil contained in the synthetic wastewater was measured. The measurement was carried out by measuring the concentration of the n-hexane extract in the medium as the extraction efficiency of 97.5% (three controls were prepared and separately calculated). A similar experiment was performed using the sample of Comparative Example 1. In addition, when neither of the samples of Example and Comparative Example 1 was added as a control, the measurement was performed by the same method. Table 9 shows the results of three measurements for each sample.

[0044]

[Table 9]

As shown in Table 9, the novel microorganism according to the present invention, Burkholderia cepacia,
eria cepacia) The AIK strain can be activated and decompose fats and oils even in a situation where nutrients other than fats and oils are extremely low.

(Test Example 9; Effect of Detergent on Degradation of Lard)
After adding pm and sterilizing, the mixture was shaken at a speed of 150 rpm for 16 hours to obtain synthetic wastewater. Next, 20 ml of the sample (containing 0.06 g of dry cells) of the example pre-cultured in the LB medium was washed with the prepared synthetic wastewater, added to 200 ml of the synthetic wastewater, and shaken at 30 ° C. and 150 rpm. Cultured. Finally, the concentration of lard in the synthetic wastewater after a predetermined time had elapsed was measured. The measurement was performed by measuring the concentration of the n-hexane extract in the synthetic wastewater after a predetermined time as an extraction efficiency of 98.6% (three controls were prepared and separately calculated). For each measurement, three samples were prepared, and the average value was determined. Table 10 shows the results.

[0047]

[Table 10]

As shown in Table 10, the novel microorganism according to the present invention, Burkholderia cepacia (Burk
It can be seen that the AIK strain (holderia cepacia) has an increased ability to degrade solid oils and fats by adding a detergent (see the results of the examples shown in Table 2 in which the same experiment was conducted with the addition of the detergent).

(Test Example 10: Influence of Detergent Addition on Decomposition of Salad Oil)
After adding 500 ppm of salad oil and sterilizing, a speed of 150
The mixture was shaken at rpm for 16 hours to obtain synthetic wastewater. Next, LB
20 ml of the sample of the example pre-cultured in the medium (dry weight: 0.
Was washed with the synthetic wastewater prepared above, and added to 200 ml of the synthetic wastewater.
Shaking culture was performed at rpm. Finally, the concentration of salad oil in the synthetic wastewater after a predetermined time had elapsed was measured. The measurement was performed by measuring the concentration of the n-hexane extract in the synthetic wastewater after a predetermined time as an extraction efficiency of 98.6% (three controls were prepared and separately calculated). For each measurement, three samples were prepared, and the average value was determined. Table 11 shows the results.

[0050]

[Table 11]

As shown in Table 11, the novel microorganism according to the present invention, Burkholderia cepacia (Burk
Holderia cepacia) It can be seen that the AIK strain has an increased resolution for liquid fats and oils by adding a detergent (see the results of the examples shown in Table 3 in which similar experiments were conducted with the addition of detergent).

(Test Example 11; Decomposition of salad oil when incorporated in activated sludge) A medium similar to the medium used in Test Example 1 was sterilized by adding 500 ppm of salad oil and 10 ppm of detergent, and then shaken at a speed of 150 rpm for 16 hours. To make synthetic wastewater. In addition, this synthetic wastewater was confirmed to have substantially the same properties as actual wastewater by a property comparison test. Next, 20 ml of the sample of the example pre-cultured in the LB medium
After washing (containing a dry weight of 0.06 g of cells) with the synthetic wastewater prepared above, it was incorporated into 200 ml of the activated sludge of Comparative Example 2, and this was added to 200 ml of the synthetic wastewater.
Shaking culture was performed at 0 ° C. and 150 rpm. Finally, the concentration of salad oil contained in the synthetic wastewater after 9 hours was measured. The measurement was performed by measuring the concentration of the n-hexane extract in the synthetic wastewater after a predetermined time as an extraction efficiency of 97.5% (three controls were prepared and separately calculated). For each measurement, three samples were prepared, and the average value was determined. The same experiment was performed using the sample of Comparative Example 2. Table 12 shows the results.

[0053]

[Table 12]

As shown in Table 12, the novel microorganism of the present invention, Burkholderia cepacia (Burk
Holderia cepacia) It can be seen that the AIK strain can exhibit excellent resolution for fats and oils even when incorporated into activated sludge.

(Test Example 12; Decomposition of Fatty Acid) An experiment was performed on the resolution of fatty acids by Burkholderia cepacia AIK strain. In addition, as a substrate, the fatty acid composition of lard and salad oil was analyzed,
Triolein, the single glyceride of oleic acid, which is most abundant in both, was used. In the experimental method, first, 500 ppm of triolein and 10 ppm of a detergent were added to a medium similar to the medium used in Test Example 1 and sterilized, and then shaken at a speed of 150 rpm for 16 hours to obtain synthetic wastewater. Next, 20 ml of the sample of the example pre-cultured in the LB medium
(Containing 0.06 g of dry cells) was washed with the synthetic wastewater prepared above, and then added to 200 ml of the synthetic wastewater.
Shaking culture was performed at 30 ° C. and 150 rpm. Finally, n- contained in the synthetic wastewater after 1 hour, 2 hours and 4 hours
The whole amount of the hexane extract was methylated, and an equal amount of Heptadecanoate acid was added as an internal standard substance, and a certain amount thereof was analyzed by gas chromatography. Table 13 shows the peak area of oleic acid corrected with the internal standard on the basis of the peak area after one hour.

[0056]

[Table 13]

As shown in Table 13, the novel microorganism according to the present invention, Burkholderia cepacia (Burk
holderia cepacia) It can be seen that the AIK strain can degrade fatty acids such as oleic acid in a short time.

[0058]

The Burkholderia cepacia AIK strain, which is a novel microorganism according to the present invention, has high fat and oil degradability in a wide temperature range. In particular, it always has a high resolution in a temperature range of about 20 to 35 ° C. The fats and oils to be decomposed are not limited to liquid fats and oils, and solid fats and oils have substantially the same resolution as liquid fats and oils. In addition, Burke Holdelia
Burkholderia cepacia AIK strain is capable of decomposing organic substances such as fatty acids, proteins, carbohydrates, and sugars in addition to fats and oils, so that BOD (biochemical oxygen demand), COD (chemical oxygen Required amount) can be reduced.

Since the method for treating wastewater according to the present invention is a method for treating wastewater mainly using bacteria capable of suitably decomposing fats and oils, it is always substantially constant without being affected by the temperature in the decomposition tank. Can be performed. For this reason, the propagation of anaerobic bacteria can be prevented, and the generation of offensive odors can be suppressed.

[Brief description of the drawings]

FIG. 1 is a graph showing test results of Test Example 3.

FIG. 2 is a graph showing test results of Test Example 7.

FIG. 3 is a graph showing an average temperature in a decomposition tank every month in a certain decomposition tank.

FIG. 4 is a graph showing an average monthly amount of an n-hexane extract in treated water in a certain decomposition tank.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat テ ー マ (Reference) C12R 1:01) C12R 1:01) (72) Inventor Satoru Kurozumi 375-1 Mizoguchi, Mizonokuchi-cho, Hino-gun, Tottori Prefecture. Asahi Sangyo Co., Ltd. F term (reference) 4B065 AA01X AC20 BA23 BB01 BB10 BC03 BC11 CA56 4D040 DD01 DD24

Claims (4)

[Claims] 1. Burkholderia cepacia
eria cepacia) AIK strain (FERM BP-7308). 2. Drainage and Burkholderia (Burkholderia)
A method for treating wastewater, comprising contacting microorganisms belonging to eria) and capable of mainly decomposing fats and oils. 3. The genus Burkholderi (Burkholderi)
The method for treating wastewater according to claim 2, wherein the microorganism belonging to a) is one of microorganisms constituting activated sludge. 4. The genus Burkholderia
The microorganism belonging to a) is Burkholderia cepacia (B
4. The method for treating wastewater according to claim 2, wherein the strain is an urkholderia cepacia) AIK strain (FERM BP-7308).