JP2562355B2 - Antibacterial agent for plant pathogenic bacteria - Google Patents

Description

TECHNICAL FIELD The present invention relates to an antibacterial agent showing efficacy against pathogenic bacteria that cause plant diseases.

(Conventional technology) Although there are various pathogenic bacteria that cause plant diseases,
Agricultural chemicals composed of inorganic and organic synthetic bactericides, antibiotics, etc. have been used for controlling them.

(Problems to be solved by the invention) However, environmental pollution by these pesticides, harm to humans and animals due to pesticide residue in the ground, and harm to soil and plants are becoming social problems. Especially, it is strongly expected to develop pesticides derived from natural products that are harmless to the human body.

On the other hand, in developing a pesticide derived from a natural product, it is required that a component having a strong antibacterial activity against plant pathogens can be easily extracted in a large amount from the natural product. The situation is that it has not been developed yet.

From the above viewpoints, the present invention aims to develop a natural product-derived agricultural music that can be easily extracted in a large amount.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present inventor focused on tea that a person drinks in large quantities, and studied whether or not tea has an antibacterial ability, and extracted tea. The present invention has been accomplished by finding that catechins contained in a product have an effective antibacterial property against certain plant pathogenic fungi and have a control action.

Pseudomonas fluorescens, Erwinia carotophora subspices atroseptica, Erwinia carotophora subspices petabass culoraum, Erwinia carotophora subsp.
Erwinia Cliensami pv. Ceae, Kurtobacter flacmum fasciens pv. Orchi, Clavibacter misiganense Subspicesis Michiganse, Pseudomonas avenae, Pseudomonas Andropogons, Pseudomonas chicory, Pseudomonas concierges napus majus naris p. , Pseudomonas solanacearum, Pseudomonas syringae pv. Eliobotlier, Pseudomonas syringae pv. Lacrimans, Pseudomonas syringae pv. Foseolicola,
Pseudomonas syringe pv. Staria fasciens,
Pseudomonas syringae pv. Theae, Pseudomonas viridi flava, Zanthomonas campestris, tomato spot bacterial pathogen and citrus canker pathogen.

The catechins include epicatechin, epigallocatechin, epicatechin gallate, and epigallocatechin gallate, and the effect of epigallocatechin gallate is particularly remarkable.

(Example) The tea applicable to the present invention is not particularly limited as long as it is included in teas, green tea which is an unfermented tea, oolong tea which is a semi-fermented tea, and black tea which is a fermented tea. Tea such as, or raw tea leaves can also be used.

a. Extraction of catechins An example of a method for extracting and separating catechins is shown as a flow chart in the drawings.

As an example of implementation, 1 kg of green tea was extracted with 10 hot water for 10 minutes, and this extract was concentrated under reduced pressure by a centrifuge (2000 × g, 10 minutes). This concentrated solution was subjected to stepwise extraction with a chromatography column (Sephadex LH-20, 10 cm, ID × 25 cmL). The first step was to extract with distilled water of 4 and 15% acetone solution of 3 and then extract A fraction with 30% acetone solution of 3, concentrate and freeze-dry to obtain crude catechin A. It was The B fraction was extracted with a 60% acetone solution of 3, concentrated and freeze-dried to obtain crude catechin B.

b. Antibacterial effect of catechins The above-mentioned crude catechin A and crude catechin B are contained in a predetermined amount (1000ppm) on a plain agar plate medium prepared by mixing medium and phytopathogenic bacteria (cell count: 10 ⁹ cell / ml) and hardening. A paper desk (filter paper with a diameter of 8 mm) was placed, and after culturing at 30 ° C. for 3 days, the value of the inhibition circle (the size of the circle that suppressed the growth of bacteria) was measured.
The results are shown in Table 1 (all tables are shown at the end of the sentence below). The calculation formula is the value of the blocking circle = {(outer diameter of blocking circle)-(diameter of paper desk)} / 2.

In the table, the control non-pathogenic bacteria are bacteria that are not pathogenic to plants.

Table 2 shows the minimum growth inhibitory concentration (the minimum concentration of catechins having an antibacterial effect). In this table, the range of the minimum concentration is due to the test by changing the concentration of bacteria (the number of bacteria), from 1.0 × 10 ⁹ (which can be regarded as the maximum concentration of bacteria) to 1.0 × 10 9. It is the concentration of efficacy for concentration ranges up to ⁵ .

From the above results, although there are differences in susceptibility depending on the bacterial cells,
All showed a clear blocking effect.

c. Antibacterial effect of epigallocatechin gallate In the same manner as in b above, but with different concentrations, the values of the inhibition circles of several kinds of fungi by epigallocatechin gallate were measured and are shown in Table 3.

From this result, it can be seen that the blocking effect appears clearly and becomes more remarkable as the concentration increases.

d. Antibacterial effect due to change in concentration Place the paper desks of crude catechin A and crude catechin B with different concentrations on the same medium as in b above with different bacterial cell concentrations, and after culturing by the same method as in b above, The value of the inhibition circle was calculated and the difference in the effect depending on the concentration was observed.

Further, the value of the inhibition circle was measured by the same method as the above b using a paper desk in which a tea extract (tea liquor) obtained by extracting 1 kg of green tea with 10 hot water for 10 minutes was directly impregnated.

 The results are shown in Tables 4 to 10 for each fungus.

This result also shows the blocking effect, and it can be seen that the higher the concentration, the more remarkable.

e. Disease control effect A solution in which the content of catechins is adjusted to 2000 ppm is sprayed onto tomatoes and summer mandarin orange seedlings grown to a plant height of about 30 cm to form a treatment zone, which is air-dried and then tomato spots are applied by the usual method. Bacterial pathogens and citrus canker pathogens were ingested by spraying and infected, and the degree of disease was examined 3 weeks later (the number of spots and the state of disease were expressed by scores and investigated).

As a control group, an untreated group without spraying catechins was provided, and the above bacteria were spray-infected in the same manner as above, and the disease severity after 3 weeks was set to 100%, and this was compared with the above example. It is shown in Table 11. As a result, it was revealed that the disease was alleviated. In addition, this result is comparable with the copper agent (brand name Germany Bordeaux) which is currently said to be the most effective against plant bacterial diseases.

(Effects of the Invention) Thus, the tea extract according to the present invention, especially the hot water extract, most preferably catechins act antibacterially against phytopathogenic fungi, and by utilizing this antibacterial effect, it is possible to prevent plant bacterial diseases. It was clarified that a moderate control effect was achieved.

Further, by using the auxiliary agent in consideration of the object and the environmental condition at the time of use, a further effect is obtained.

In particular, since this active ingredient is a substance derived from a natural product contained in leaf tea, which has been used as a beverage by humans for many years, it has little adverse effect on humans and animals from the viewpoint of toxicity and environmental pollution, and is extracted and separated. Mass production is possible because the method is relatively simple.

[Brief description of drawings]

The drawing is a flowchart showing the method for extracting and separating tea catechins.

Front page continuation (72) Inventor Yuko Hezaka 21 Goddess Sagara-cho, Haibara-gun, Shizuoka Itoen Central Research Institute Co., Ltd. (72) Masao Goto 3800-233 Otani, Shizuoka-shi, Shizuoka (56) References 56-38591 (JP, B2) The Journal of Applied Applied Biology Vol. 64 (April 1988) P. 293-297

Claims (1)

(57) [Claims] 1. Pseudomonas fluorescens, Erwinia carotophora subspsis atroceptica, Erwinia carotophora, which contains one or more of epicatechin, epigallocatechin, epicatechin gallate, and epigallocatechin gallate as active ingredients and is a plant pathogen. Sub-Spithesis Petabasculorum, Erwinia Carotophora Sub-Spisys Carotophora, Erwinia Chrysansemi, Erwinia Cliensami pv.
Tseae, Curtobacterium flakhamfaciens pv. Orchi, Clavibacter misiganense subspicesis michiganse, Pseudomonas avenae,
Pseudomonas Andropogons, Pseudomonas
Chicory, Pseudomonas fix erectae, Pseudomonas marginalis pv.
Syringe pv. Lacrimance, Pseudomonas syringae
pv. fozeolicola, Pseudomonas syringae pv. staria fasciens, Pseudomonas syringae pv. theae, Pseudomonas viridi flava, Xanthomonas campestris, an antibacterial agent for phytopathogenic fungi characterized by bacterial tomato spot fungus and citrus canker bacterium.