KR100580857B1 - Disposal method of food wastes using the mixture of Bacillus smithi and thermotolerant yeast - Google Patents

Abstract

The present invention relates to a mixed strain ATS-1 (KCTC 10637BP) of Bacillus smithi strain and thermophilic yeast that promotes biodegradation of food waste having a high moisture content, and a waste disposal method using the mixed strain. More specifically, the present invention uses the bacterium ATS-1 (KCTC 10637BP) mixed with a thermophilic bacterium Bacillus smithi and a thermophilic yeast to grow at high temperatures of 37 ° C to 60 ° C. In a high temperature environment that can be increased, the present invention relates to a method of treating food waste efficiently without significantly lowering the water content.

Bacillus Smith Eye * Thermophilic Microorganisms * Food Waste * Water Content * Moisture Control * Biodegradation

Description

Disposal method of food wastes using the mixture of Bacillus smithi and thermotolerant yeast}

Figure 1a is a photograph of the appearance of the waste extinction device used in the present invention.

Figure 1b is a photograph of the interior of the garbage extinguishing device used in the present invention.

Figure 2 shows a schematic diagram of the waste extinction device used in the present invention.

The present invention relates to a mixed strain ATS-1 (KCTC 10637BP) of Bacillus smithi strain and thermophilic yeast that promotes biodegradation of food waste having a high moisture content, and a waste disposal method using the mixed strain. More specifically, the present invention is the decomposition of microorganisms using ATS-1 (KCTC 10637BP), which is a mixed strain of Bacillus smithi , a thermophilic microorganism growing at a high temperature of 37 ℃ to 60 ℃ and thermophilic yeast In a high temperature environment that can increase the activity, the present invention relates to a food processing method capable of efficiently dissolving food waste without significantly lowering the water content.

Korea's daily waste generation amounted to 46,438 tons (as of 2000), and the amount of waste generation has increased rapidly due to the increase of population, industrialization of cities and urban concentration over the past 20 years. In 1991, 89.2% of household waste was landfilled and only 7.9% was recycled.In 2000, the landfill rate was reduced to 47.0% due to the waste-based waste disposal system and recycling policy, while the recycling rate was 41.3%. It is increasing.

Among them, the disposal of food waste mostly depends on the landfill, but since food waste has a high water content, landfill itself is a source of leachate, and it is easily decayed during the collection and transportation process, and is likely to cause various problems such as odor. . Although there is another method of incineration, the incineration efficiency is lowered due to a large amount of water, and thus the treatment cost is high and environmentally harmful substances such as dioxins are emitted. In order to solve these problems, a plan for recycling food waste by composting, feeding, and energy has been in progress.

Anaerobic digestion can be seen as an advantage over composting in that it can target wet biodegradable waste and recover energy, but it also has the disadvantage of larger facility size and higher maintenance costs than composting. As for thermal treatment, there is no technically proven commercial treatment facility other than incineration to date, but a gasification melting facility that integrates with domestic waste is under development (Jung, Il-lok, 2002).

In the composting method, annihilation type, fermentation type, and dry type were installed and operated.In general, the type of water control agent (sawdust, rice husk, etc.) and microorganisms are used to break down food waste (organic matter). Difficulties and rising prices have been pointed out as problems.In the case of dry food, food waste is added and hot air, a heater, or an indirect steam heating device is applied at a temperature of 70-120 ° C. to evaporate moisture and at the same time dry contents. Considering the method of pulverizing and reducing by the stirring action or the economics of the heating apparatus, the effectiveness is inferior in the practical screen. On the other hand, the high temperature aerobic method using heat energy generated by microbial reaction without additional heat supply from the outside has been studied as a method of purifying organic wastewater, but it has not been applied in the field due to the lack of various control technologies.

This treatment method is the key to activate the thermophilic microorganisms, and there is no method to maintain the temperature continuously, so it has not reached the commercialization stage like various wastewater treatment methods currently used. The advantages of the processes using the heat of reaction are that the reaction proceeds at high temperature, so the removal rate of organic matter is high, and it shows stable processing efficiency for the load of organic matter. Is that you can get

In the case of the double composting and extinguishing method, a bulking agent such as sawdust is required, and as the volume of the device increases, the waste disposal cost is high. In addition, during the composting process, most organics are converted to mercaptan, water, microbial cells, thermal energy, and humus, which are produced in carbon dioxide, ammonia, aerobic and anaerobic conditions. This results in inconvenient cost of using the deodorizing tower and platinum catalyst to remove it. Recently, in order to reduce these additional costs, a method of recycling exhaust gas has been introduced, but the platinum catalyst for removing odor is generally used, and thus, fundamental cost reduction has not been achieved.

The representative microorganisms currently used in food waste composting and extinction methods in Korea are microbial species known as microbial species that can degrade cellulose, such as coryneform, nocardioform, and true fibrous bacteria filamentous bacteria, actinomycetes. These bacteria play a major role in the degradation of hydrocarbons, plant residues and soil compost. Some microorganisms belonging to this group also degrade pesticides. Fibrous actinomycetes, primarily belonging to Streptomyces , produce odorous compounds, such as geosmin, which give a characteristic land odor (Parker, 2001). Soil microorganisms can be classified based on (1) preference for readily available or difficult substrates with respect to organic matter treatment, and (2) concentrations of substrates they require. At high nutritional levels, microorganisms such as Pseudomonas react quickly to readily available substrates such as sugars and amino acids. Indigenous forms tend to make the most of natural organics. These are the same as Arthrobacter and many soil actinomycetes.

In case of actinomycetes microbial growth rate is faster than 70%, both the composting and extinction methods of previously developed food waste are recommended to set the water content between 40 ~ 60%. However, this water content control may be possible in some large-scale waste disposal plants, but is most likely not possible in homes, food service establishments, and large distribution markets.

In this situation, the present inventors have found that the growth at a high temperature of 37 ~ 60 ℃ and a result of research on microorganisms capable of decomposing the food waste with high water content, Bacillus Smith children (Bacillus smithi) and decomposing the mixed culture of the thermophilic yeast waste When applied to the composition, the biodegradability of food waste increases as the decomposition activity of the microorganism increases at high temperature, and found that its activity is high even for food waste having a high water content and completed the present invention.

Accordingly, an object of the present invention is to provide ATS-1, which is a mixed strain of thermophilic microorganism Bacillus smithi and thermophilic yeast having excellent food waste resolution.

It is also an object of the present invention to provide a microbial preparation containing ATS-1, a mixed strain of thermophilic microorganism Bacillus smithi and thermophilic yeast, as an active ingredient.

Another object of the present invention is to provide a food waste treatment method using a microbial agent containing ATS-1 (KCTC 10637BP), which is a mixed strain of Bacillus smithi and thermophilic yeast.

In order to achieve the above object, in the present invention, decomposition of food waste using ATS-1, which is a mixed strain of Bacillus smithi and thermophilic yeast, which is a thermophilic microorganism growing at a high temperature of 37 to 60 ° C. It is characterized by promoting.

Hereinafter, the present invention will be described in detail.

The general characteristics of Bacillus smithi and pyrogenic yeast of the present invention are as follows.

Bacillus smithi is a food-degrading bacterium used to extinguish foods, and has an excellent resolution on cellulose, a hardly degradable substance, and can decompose N-acetyl-glucosamine, a cell wall component.

In addition, the thermophilic yeast has a function of suppressing the odor by alcoholic fermentation of food waste like the general yeast, and can be used with Bacillus smithi, which is a thermophilic microorganism by acting at a high temperature.

Bacillus smithi and thermophilic yeast were mixed strains and were deposited by the inventors to the Biotechnology Center of Korea Research Institute of Bioscience and Biotechnology as deposit number KCTC 10637BP (Date: 2004.05.19), and the mixed strains were ATS-1. Named it.

The present invention provides a waste treatment method using a microbial agent containing ATS-1, which is a mixed strain of Bacillus smithi , which is a thermophilic microorganism, and a thermophilic yeast, thereby treating food waste at a high temperature at which microbial activity increases. Unlike conventional food wastes, which had to adjust the water content within 45 ~ 60% (Jung and Shin 1998, Shin and Hwang 1998, and Bae Jae-Geun 2001), the water dissipation efficiency is increased even at 85% or more of water content and used for waste extinction. The amount of moisture control agent can be significantly reduced.

Hereinafter, the present invention will be described in more detail with reference examples and test examples, but the present invention is not limited only to these examples.

Reference Example 1 Isolation and Identification of Microorganisms

In order to identify the microorganisms capable of breaking down fiber, protein, fat, and starch among the bacteria in the soil, separation was performed as follows.

After sampling the sample in the manure near Paro Lake, Hwacheon-gun, Gangwon-do, soil extract media was used to separate the microorganisms. The humus soil was placed in the first distilled water and shaken for 30 minutes at 100 ℃ in an autoclave and filtered before use. A small amount of the collected sample was added and incubated at 37 ° C. and 60 ° C. for pure separation.

In order to separate the microorganisms having excellent cellulose resolution among the separated microorganisms, the separated microorganisms were first diluted with 1/100 (w / v) in sterile distilled water and shaken. Then, the supernatant was plated in enrichment nutrient agar (NA) containing CMC (carboxymethyl cellulose) and resazulin, and then incubated at 37 ° C. and 60 ° C. for 24 hours, respectively. 16S rDNA sequencing was performed on the strains showing the most distinct color of CMC-NA medium. As a result, it was confirmed that the isolated strains Bacillus smithi and thermophilic yeast, and their mixed strain was named ATS-1 (KCTC 10637BP), and deposited in the Korea Institute of Bioscience and Biotechnology.

Reference Example 2 Fabrication of Garbage Extinction Apparatus

In order to aerobic extinction of food waste, a waste extinguishing apparatus having a waste disposal capacity of 20 kg / day and 100 kg / day was used as a test. The structure of the experimental apparatus is shown in Figs. 1A, 1B and 2. The 20kg / day extinction device was manufactured in the drum type, and was intended to investigate the possibility of extinction without injecting the internal impeller and the external inlet air. The 100kg / day extinction reactor was made of transparent acrylic with 1.0cm thickness to visually confirm the extinction process, and the operation of the stirring shaft for mixing the internal materials was performed in continuous operation to maintain aerobic conditions. The air forced the hot air heated to 32 ℃ by the heater into the ring blower.In order to facilitate the evaporation of water, the entire reactor was sealed and only the waste inlet at the top of the reactor was opened to control the pressure. It was set as.

[Examples 1-9]

As shown in Table 1 below, the weight of the food waste, the water content, and the temperature of the extinguisher, respectively, were put in the extinguisher of Reference Example 2, and then ATS-1 (combined strain of Bacillus Smith eye and thermophilic yeast) and coco feed The microbial agent consisting of (moisture control agent) was treated to each food waste to prepare Examples 1 to 9.

ATS-1 Coco feed Food waste weight Water content Temperature of extinguisher Example 1 15 ml 2 kg 63.4 kg 84.7% 44.5 ℃ Example 2 15 ml 2 kg 63.4 kg 75% 44.5 ℃ Example 3 15 ml 2 kg 63.4 kg 40% 44.5 ℃ Example 4 15 ml 2 kg 63.4 kg 84.7% 27.5 ℃ Example 5 15 ml 2 kg 63.4 kg 84.7% 22.5 ℃ Comparative Example 1 - 2 kg 63.4 kg 84.7% 44.5 ℃ Comparative Example 2 - 2 kg 63.4 kg 75.7% 44.5 ℃ Comparative Example 3 - 2 kg 63.4 kg 40.7% 44.5 ℃

Test Example 1 Resolution of Food Waste According to Water Content

In order to compare the waste resolution of the mixed strain according to the present invention according to the water content of the food waste, the experiments were performed as follows for Examples 1 to 3.

The decay device was prepared in Reference Example 2, and the stirring device of the decay device was operated at 6000 rpm for 24 hours. In addition, the temperature of the extinction was all 44.5 ℃, and the weight of food waste before the introduction of the microbial agent was all 63.4kg. Water content of food waste was 84.7%, 75% and 40%, respectively. Food waste was stored in the restaurant of Kangwon National University high school. The main ingredients were rice, vegetables, fish, tofu, and vegetables (Radish, Chinese Cabbage, Buttercup, etc.). The results are shown in Table 2 below.

Changes in Food Waste Weight According to Water Content Before input 24 hours 48 hours 1 week 2 weeks Example 1 63.4 kg 52.2 kg 51.5 kg 35 kg 5.6 kg Example 2 63.4 kg 52.1 kg 48.0 kg 31.0 kg 5.5 kg Example 3 63.4 kg 53.8 kg 49.5 kg 29.9 kg 5.0 kg Comparative Example 1 63.4 kg 59.2 kg 56.5 kg 43.3 kg 33.1 kg Comparative Example 2 63.4 kg 58.4 kg 54.7 kg 39.9 kg 28.6 kg Comparative Example 3 63.4 kg 58.2 kg 53.8 kg 38.3 kg 13.5 kg

As shown in Table 2, when the microbial preparation containing the mixed strain ATS-1 of the present invention was applied to food waste having different moisture content, there was no significant difference in resolution, but ATS-1 (KCTC 10637BP) was not added. In this case, it was found that the higher the water content, the faster the rate of microbial degradation.

[Test Example 2] Comparison of garbage resolution according to the internal temperature of the extinguisher

In order to compare the waste resolution according to the internal temperature of the extinction period of the food waste of the microbial preparation including the mixed strain of the present invention, the experiments were performed as follows for Examples 1 and 4 to 5.

The decay device was prepared in Reference Example 2, and the stirring device of the decay device was operated at 6000 rpm for 24 hours. In addition, the water content of the food waste was all 84.7%, and the weight of food waste was 63.4 kg before adding the microbial preparation. The internal temperatures of the extinction group were 44.5 ° C, 27.5 ° C and 22.5 ° C, respectively. Food waste was used was obtained under the same conditions as in Test Example 1, the results are shown in Table 3 below.

Before input 24 hours 48 hours 1 week 2 weeks Example 1 63.4 kg 52.2 kg 51.5 kg 35 kg 5.6 kg Example 4 63.4 kg 55.1 kg 52.0 kg 43.0 kg 16.5 kg Example 5 63.4 kg 55.8 kg 53.1㎏ 45.9 kg 13.6 kg

As shown in Table 3, when the temperature inside the quenching machine is 27.5 ° C and 22.5 ° C, the rate of decomposition of food waste was slow compared to the case of treatment at 44.5 ° C for 24 hours. Shows an increase in degradation activity for food.

Test Example 3 Determination of Odor of Food Waste

In order to determine the food waste odor removal effect of the mixed strain ATS-1 (KCTC 10637BP) of the present invention, the degree of odor was measured in Examples 1-3 and Comparative Examples 1-3.

The measurement of odor was performed by selecting 20 sensory testers and measuring the odor of food waste after 1 week and 2 weeks, respectively. 7-point sign scale method (very severe (1 point), normal (4 points), almost none (7) Point) and the like, and the results are shown in Table 4 below.

1 week 2 weeks Example 1 4.4 4.8 Example 2 4.1 4.7 Example 3 4.6 5.1 Comparative Example 1 2.1 1.9 Comparative Example 2 1.8 2.3 Comparative Example 3 1.7 2.6

As shown in Table 4, when the ATS-1 (KCTC 10637BP) of the present invention is added, the degree of odor was much smaller than that of the case.

As described above, the food waste treatment method using a microbial agent containing ATS-1 (KCTC 10637BP), which is a mixed strain of Bacillus smithi and thermophilic yeast of the present invention, increases the degradation activity of microorganisms. It can effectively treat food waste by using microorganism at high temperature of 37 ~ 60 ℃, and it can reduce the use of moisture control agent to lower water content by having decomposing activity on food waste with high moisture content compared with the existing method. In this way, food waste can be effectively disposed of while reducing food waste disposal costs significantly.

Claims (2)

A food waste disposal method using a microbial agent containing a mixture of thermophilic microorganism Bacillus smithi and thermophilic yeast ATS-1 (KCTC 10637BP). A microbial composition for decomposing food waste containing ATS-1 (KCTC 10637BP) which is a mixed strain of Bacillus smithi and yeast as a high temperature microorganism.

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