JP4566757B2 - Microbial materials - Google Patents

Description

  The present invention relates to a microbial material containing a microorganism having an antagonistic action against a plant pathogen.

  There have been many studies on microbial materials that actively use microorganisms that have antagonistic action against plant pathogens (called antagonistic microorganisms or antagonistic bacteria) to control disease. There are very few success stories on actual farms. Here, an antagonistic bacterium is a microorganism that suppresses the growth and activity of a specific bacterium, and can suppress the growth and activity of a pathogenic bacterium, and as a result, can reduce a disease to a plant. In particular, in the current situation where there is a call to shift to organic farming that reduces the use of pesticides that are concerned about safety and environmental destruction, and ecologically utilized (environmental conservation) farming such as reduced or non-pesticide farming It is no exaggeration to say that the technology of microbial materials that function as an agrochemical using such antagonistic bacteria is a dream technology, and its development is eagerly desired.

  However, as described above, although various studies have been made, there are few successful cases on actual farms. The reason for this is that there are a great variety of soil bacteria in the farm soil. In such farms, the state of the antagonistic culture solution (see, for example, Patent Document 1), the culture material, Even if a large amount of antagonistic bacteria (see, for example, Patent Document 2) in which a large amount of antagonistic bacteria were propagated at a time, they lost the competition with other microorganisms (those that have settled in the soil). This is probably because antagonistic bacteria cannot often take root in the soil.

  On the other hand, the applicants already use a technique for obtaining dry immobilized microorganisms (see, for example, Patent Documents 3 and 4), and use surplus sludge discharged from the activated sludge facility as a carrier, and determine antagonistic bacteria as specific conditions. By producing microbial material by fixing it to a carrier under the bottom, it achieves effective use of surplus sludge, and at the same time, when actually used on a farm, it swells due to moisture in the soil and restores the life activity of antagonistic bacteria. Thus, proposals have been made for products that have been confirmed to function effectively as microbial materials (see, for example, Patent Document 5).

  The microbial material with the above-described surplus sludge as a carrier and the antagonistic bacteria fixed to the carrier is much higher in the diseases caused by the antagonistic bacteria compared to conventionally known compost products mixed with antagonistic bacteria. Although a reduction effect can be obtained, in order to make it more effective against a specific plant pathogen and a practical product, it can exhibit a better effect against the pathogen. When used in plants, the effect is more reliably exhibited, and further improvement is required to make the product effective for a longer period of time and excellent in usability.

Japanese Examined Patent Publication No. 7-101815 Japanese Patent Publication No. 6-192028 Japanese Patent Publication No. 4-48436 Japanese Examined Patent Publication No. 6-73451 JP 2001-308714 A

  Therefore, the object of the present invention can be utilized for a microbial material in which antagonistic bacteria are fixed in a state where the activity is maintained and swells with moisture in the soil during use to restore the biological activity of the antagonistic bacteria. The object is to find a new antagonistic bacterium and to provide a highly practical microbial material in which the function as a so-called pesticide is more effectively demonstrated.

The above object has been achieved by the present invention described below. That is, the present invention relates to [1] a microbial material used for plant disease control comprising at least an antagonistic microorganism and a solid nutrient medium, wherein the antagonistic microorganism is a Trichoderma asperumum F288 strain (Accession number: NITE P-53). ) Containing microbial materials.

The following are mentioned as a preferable form of this invention . [2] Furthermore, microbial material above SL containing vermiculite materials are clay mineral has a [3] antagonistic microorganism antagonistic microorganism cultured in a solid nutrient medium, and, is the culture, and is discharged from food factories upper Symbol of microbial material of the work was performed at a solid culture method using the organic plant residues, [4] the granular or above SL microorganisms material in the form of pellets.

  According to the present invention, when planted in the soil together with crop seedlings and seeds, the life activity of antagonistic bacteria including Trichoderma asperellum F288 strain, which has been fixed in a state of maintaining the activity, swells and recovers due to moisture in the soil. In addition, a microbial material is provided that exhibits a sufficient function as a so-called agricultural chemical and that maintains a certain quality while using microorganisms. Furthermore, according to the preferable form, the above-mentioned effect is maintained over a longer period of time, and a microbial material excellent in practicality that is easy to handle when actually used in farm soil is provided.

  Next, the present invention will be described in detail by giving preferred embodiments. As a result of intensive studies to solve the above-described problems of the prior art, the present inventors are fixed in a state where the activity is maintained, and swell with moisture in the soil during use to recover the life activity of the antagonistic bacteria. The present inventors have found a Trichoderma asperum F288 strain, which is a novel antagonistic microorganism that exhibits high functions as a so-called pesticide and can be effectively used as a microbial material, and has reached the present invention.

  A novel Trichoderma asperellum F288 strain (accession number: NITE P-53) that characterizes the present invention will be described. The microorganism is a fungus belonging to the genus Trichoderma, but as a result of intensive studies on the microorganism, the present inventors have found that the microorganism is a white coat or purple coat disease of fruits such as apples, pears, grapes and tangerines. It was confirmed that there was a high antagonism against Rosella necatrix and Helicobasidium monpa, which are the pathogens of. The Trichoderma asperellum F288 strain was also confirmed to have a high antagonistic action against Streptomyces Scabies, which is a pathogen of potato scab. Further, according to further studies by the present inventors, this microorganism exhibits a high antagonistic action as described above against fruit trees and potato pathogens, and at least a microbial material comprising a solid nutrient medium. In this case, it is fixed in a state where the activity is maintained, and when used, it swells with moisture in the soil and recovers its life activity, and the above antagonistic action is exhibited at a high level, so-called pesticide. It was confirmed that it can be used effectively.

The microbial material according to the present invention preferably contains Trichoderma asperellum F288 strain in a range of about 10 ² to 10 ⁷ cells per gram of the finally obtained microbial material.

  The microorganism material according to the present invention may be any material as long as it uses Trichoderma asperellum F288 strain as an antagonistic microorganism and contains a solid nutrient medium. As the Trichoderma asperellum F288 strain used for the microbial material according to the present invention, it is preferable to use a microorganism that has been purely microbiologically cultured in advance. As a method for culturing antagonistic bacteria, a conventionally known microbiological pure culture method may be used, but it is particularly preferable to use a solid culture method using an organic plant residue discharged from a food factory. Specifically, it is preferable to culture using a solid nutrient medium composed of organic plant residues such as bran, rice bran, okara and red bean residue.

  The microbial material according to the present invention can be obtained, for example, by further mixing Trichoderma asperellum F288 strain previously cultured by a solid culture method or the like as described above with a solid nutrient medium. In the present invention, it is preferable that the solid medium used for culturing the Trichoderma asperellum strain F288 and the solid nutrient medium to be further mixed are the same.

  In addition to the above, the microbial material according to the present invention may further contain a vermiculite material that is a clay mineral. Here, clay is generally an aggregate of sticky fine particles that are strongly hydrophilic and produce plasticity when added with water, and exhibit rigidity when dried. Clay minerals are produced as the main component of the clay. This refers to hydrated silicate. According to the study by the present inventors, it is particularly preferable to use vermiculite among clay minerals.

  Vermiculite that can be used in the present invention is also called a meteorite, and is a secondary mineral whose chemical composition is not constant, although alumina, silica, and magnesia are the main chemical components. Vermiculite is a clay mineral having a layer structure, and its appearance is biotite-like. Vermiculite marketed for soil and building materials is a heat-treated vermiculite raw material. The heat treatment vaporizes the water connecting the layers, resulting in a light, porous, granular product that expands in volume and has an infinite number of air layers between the layers. Thus, since vermiculite is porous, it becomes a good fixing material for antagonistic bacteria.

  In the present invention, commercially available vermiculite for soil and building materials can be used, but preferably, powdered vermiculite is used as waste in the production process of vermiculite. A product obtained by mixing such powdered vermiculite with the above-mentioned raw material and granulating it by a known method becomes a very inexpensive product. In addition, if powdered vermiculite is mixed with the above-described raw material and pelletized by a known method, a pellet-like microbial material having excellent handleability can be obtained easily and inexpensively. Furthermore, the use of powdered vermiculite as waste enables effective use of resources that have been disposed of at the same time, while at the same time reducing the cost of waste processing in vermiculite production. Is also effective.

  The above-mentioned microbial material containing vermiculite is produced from a mixture obtained by adding vermiculite, a solid medium in which antagonistic microorganisms are cultured, and an organic plant residue which is a solid nutrient medium. As the organic plant residue, it is preferable to use one selected from bran, rice bran, okara and red bean residue, which is also suitable for culturing antagonistic bacteria. According to the study by the present inventors, a microbial material containing vermiculite is a product that maintains a certain quality and maintains a more effective effect despite the fact that it uses the life activity of microorganisms. Become.

  As a preferred form of the microbial material according to the present invention, a mixture comprising Trichoderma asperrum strain F288 cultured in a solid medium and an organic plant residue such as wheat bran, or further, a vermiculite material The mixture which added the clay mineral like this is granulated or pelletized. The microbial material having such a structure is easy to handle, and when planted in the soil together with crop seedlings and seeds, the antagonistic bacteria grow well in the soil, and the disease-reducing effect on the plant by the antagonistic bacteria is stable. And it lasts for a long time. According to the study by the present inventors, the Trichoderma asperellum F288 strain used in the present invention is effective when the microorganism is active when it is used as a microbial material in a practical form excellent in handleability and productivity as described above. The microorganism is fixed in a maintained state, and further, when it is contained in the soil at the time of use, the microorganism grows smoothly without dying, and can exhibit its high antagonism in the soil.

  As described above, the microbial material according to the present invention formed into a granular or pellet form is excellent in handleability. In particular, the microbial material in the form of a pellet is at the same time longer when it is contained in soil. Over time, the disease-reducing effect on plants by antagonistic bacteria persists. Whether or not the microbial material according to the present invention is in the form of pellets may be determined according to the type of plant expected to reduce the disease of the microbial material. For example, in the case of those used for plants that can be harvested in a short time such as various vegetables, it is not necessary to pelletize them, but in the case of trees such as apples, plants by antagonistic bacteria for a longer period of time. It is effective to use a pellet-like microbial material that maintains a disease-reducing effect on the bacterium.

  As described above, the microbial material according to the present invention includes a solid nutrient medium composed of organic plant residues selected from, for example, bran, rice bran, okara and red bean residue, along with Trichoderma asperellum F288 strain. As mentioned above, when this microbial material is applied to the soil, the antagonistic bacteria having a sufficient substrate of the antagonistic bacteria (food) are likely to grow, and the effect is sustained for a longer period of time. The effect is that According to the study by the present inventors, among the above, the microbial material particularly using the bran is contained in the soil, and even when it is in a state of competing with other microorganisms living in the soil, it is antagonistic. It is excellent in the growth of bacteria and the effect of antagonistic bacteria lasts for a long time.

  A specific method for producing a microbial material according to the present invention will be described. The microbial material according to the present invention is not limited as long as it contains a solid medium in which Trichoderma asperellum F288 strain is cultured, a solid nutrient medium, and vermiculite as necessary. Or it is preferable to use a pellet form. In the case of a granular product, it is manufactured by a known method using a tumbling granulator or the like using raw materials such as a solid medium and a solid nutrient medium in which Trichoderma asperellum F288 strain is cultured. Can do. Specifically, a wet powder raw material obtained by adding water to the above-mentioned powdery raw material is agglomerated and granulated by moving it with a granulator by rolling, vibration, stirring, etc. Examples thereof include a granulation method utilizing an agglomeration phenomenon caused by spraying an aggregating binder or water onto the dry powder in the layer.

  Examples of the aggregating binder used in the above case include starches such as corn starch, wheat flour, processed starch, CMC (carboxymethylcellulose), polyvinyl alcohol (Poval), which have strong caking power / water supply capacity / water retention capacity. ) Etc. can be used. In the case of using these binders, the binder may be mixed in the powder raw material, and water may be sprayed while applying rotation or vibration to the mixture, or the binder may be applied while rotating or vibrating the powder raw material. An aqueous solution may be sprayed.

  The microbial material according to the present invention may be in the form of pellets, but as a manufacturing method in that case, a conventionally known extrusion granulation method can be used. Specifically, a powdered raw material to which antagonistic microorganisms are cultured, solid nutrient medium, and clay mineral, and optionally a binder, is added to water to mix to obtain a wet powder raw material, which is extruded. By extruding the mixture from the holes of the machine, then cutting it into an appropriate length and drying it, a pellet-like microbial material can be easily obtained. The amount of water added at this time may be any as long as the wet powder raw material mixture can be extruded.

  The granular or pellet-shaped product obtained by molding the raw material mixture obtained as described above can be made into a solid microbial material product with high strength if it is subsequently dried. As the drying temperature, it is preferable to perform dehumidification and drying treatment at a slightly higher ordinary temperature, for example, a temperature of 40 ° C. or lower. The specific drying temperature may be appropriately determined according to the temperature resistance of the target microorganism.

  The microbial material according to the present invention obtained by the method as described above consists of Trichoderma asperellum F288 strain, solid nutrient medium, and vermiculite and binder added as necessary. Included in a dry and immobilized state. When the microbial material according to the present invention is sown on a farm, it swells in contact with moisture in the soil, and the Trichoderma asperellum F288 strain fixed in the solid nutrient medium or vermiculite is swollen again by swelling. It regains its activity and exhibits an antagonistic action that suppresses the growth and activity of pathogenic bacteria on the farm, and is effective in reducing disease on the farm.

  When Trichoderma asperellum F288 strain is sown on a farm, it regains its activity by being swollen with water in the soil, but at that time, organic plant residues that are solid nutrient media coexist around the fungus. Since the antagonistic substrate (food) is sufficiently present, even when it competes with a large amount of microorganisms such as pathogenic bacteria already present in the soil, the antagonistic bacteria grow well without dying, A state in which antagonistic bacteria are always present in the soil can be formed. In particular, the microbial material in the form of pellets has sufficient strength and is not only excellent in handleability when going to the farm, but also gradually swells from the surface to the inside due to moisture in the soil, The antagonistic action can be maintained for a longer period of time as compared to those simply mixed or granular.

  Furthermore, when the microorganism material is in the form of coexisting vermiculite, the effect is further sustained. The present inventors consider the reason as follows. In other words, in the microbial material in the form of coexisting vermiculite, the vermiculite in the material is as if it coated the surface of organic plant residues such as bran, this state constitutes the microbial material As a result of effectively inhibiting the organic plant residue that is being used as food for various microorganisms present in the soil and providing an environment in which the contained antagonistic bacteria can selectively grow and proliferate, It is considered that the antagonistic action that suppresses the growth and activity of the pathogenic bacteria was exhibited, and that the effect of the antagonistic bacteria lasted for a long time.

  In view of the above-described characteristics, the microbial material according to the present invention may be selected according to the plant to be used by selecting a raw material and selecting a shape (whether or not to be granulated or pelletized, or size). For example, in the case of a microbial material intended for vegetables, the mixture may be used as a mixture or a granular microbial material product without being pelletized. The microbial material obtained in this case is relatively brittle. On the other hand, when producing microbial materials targeting fruit trees such as apples, it is preferable to use pellets, the size of which varies depending on the type of plant, the type of antagonistic bacteria to be fixed, etc. What is necessary is just to determine suitably in the range.

  In addition, the microbial material according to the present invention is expected to be used in a large amount. However, if the powdery vermiculite that has been disposed of in the past is used as an antagonistic material for immobilizing bacteria, vermiculite At the same time, it can be used effectively, and at the same time, manufacturing costs can be kept low, and cheaper and more practical products can be provided.

Next, the present invention will be described in more detail with reference to examples of the present invention.
<Example 1>
First, a sterilized 10 kg wheat bran is used as a solid medium of Trichoderma asperellum F288 strain of the genus Trichoderma having antagonistic activity against apple white rot and purple rot, Rosella necatrix and Helicobasidium monpa. The cells were inoculated to 10 ³ cells / g and cultured for 2 weeks. Next, the obtained culture and the wheat bran similar to that used in the above culture are mixed in a mass ratio so that each has a blending ratio of about 1:10, granulated, and granulated. Obtained microbial material.

<Example 2>
Trichoderma asperellum F288 strain cultured in wheat bran as used in Example 1, and wheat bran and vermiculite (manufactured by Hiruishi Chemical) similar to those used in the culture, each in a mass ratio of about 1 : Weighed so as to have a blending ratio of 5: 1, added tap water and mixed to obtain a wet powder. Next, the wet raw material obtained above was molded, cut and dried by an extrusion granulation type extruder to obtain a pellet-shaped microbial material of about φ7 mm × about 3 cm.

<Comparative Example 1>
The pellet-like microbial material obtained in the same manner as in Example 2 was sterilized with an autoclave, and this was used as the material of Comparative Example 1.

<Evaluation>
About the granular or pellet-like microbial materials of Examples 1 and 2 and Comparative Example 1 obtained above, the effects when actually planted on a farm were examined as follows. The microbial materials of the examples and comparative examples obtained above were placed in 1 kg / piece into the roots of apples infected with white coat scab and purple coat scab, each 10 serving as a test plot, 2 years The later state was observed and evaluated.

(Evaluation results)
As a result, all the microbial materials of Examples 1 and 2 applied to the roots were healthy and never exhausted. On the other hand, after the pelletization, the sterilized microbial material of Comparative Example 1 was completely depleted. As a result, the culture obtained by culturing the antagonistic bacteria and the solid nutrient medium were mixed and granulated, and the mixture obtained by granulating and the mixture obtained by further adding vermiculite was obtained. It was confirmed that all of Example 2 sufficiently functioned as microbial materials. This is because the life of the antagonistic bacteria is recovered by swelling with moisture in the soil, and the antagonistic bacteria are immobilized in a state in which the function can be exerted. It means that it was able to last for a period.

  Further, when the effects of the microbial materials of Examples 1 and 2 were compared in detail, it was found that the effect of the pelletized example 2 was slightly superior to the granular material of example 1. This means that by pelletizing, the above-described effects can be sustained for a longer period of time, and the pelleted material can leave antagonistic bacteria in the soil for a longer period of time than the granular material. It shows that it becomes.

<Example 3>
Inoculated Trichoderma asperumum F288 strain of Trichoderma antagonism against Streptomyces Scabies, a pathogen of potato scab, to 10 ³ cells / g using 10 kg of wheat bran as a solid medium. Cultured for 2 weeks. Next, the obtained culture, a wheat bran similar to that used in the above culture, and a vermiculite similar to that used in Example 2 were blended in an approximate 1: 5: 1 ratio on a mass basis. It mixed so that it might become a ratio, and it was set as the microorganism material of a present Example.

  Potato seedlings were planted in the test area of 1a (Earl) where the microbial material of the present example obtained above was applied to the soil of the field where potato scab disease occurred about 100 L / 1. When harvested in 3 months, no scab was observed in all the harvested potatoes.

<Comparative example 2>
For comparison, when composting raw garbage by fermenting and ripening to make fertilizer, a compost product obtained by initially containing 5% by volume of the same antagonistic bacteria used in this example, Potato seedlings were planted in test plots subjected to the same conditions as in Example 3. When harvested in 3 months, the occurrence of scab was observed in 1/3 of the harvested potatoes.

As an application example of the present invention, when actually used on a farm, the life activity of the antagonistic bacteria that have been swollen by the moisture in the soil and maintained the activity is recovered, and the fruit trees such as apples are white. Microbial material products that act as so-called pesticides against herring wings, purple scabs, and potato scabs. Compared to conventional products, the product has a long-lasting effect, is easy to handle, is a product that uses microorganisms called antagonistic bacteria, and has a high practical value that maintains a certain quality. It can be a simple microbial material product.

Claims (3)

A microorganism material for controlling disease of a plant comprising at least an antagonistic microorganism and a solid nutrient medium, wherein the antagonistic microorganism comprises Trichoderma asperellum F288 strain (Accession No .: NITE P-53) Materials.   Furthermore, the microbial material of Claim 1 containing the vermiculite material which is a clay mineral. The microbial material according to claim 1 or 2 , which is in the form of particles or pellets.