CN1513327A - A kind of microbial pesticide and preparation method thereof - Google Patents

Abstract

A microbial pesticide and a preparation method thereof, characterized in that the active strain of the microbial pesticide is a new strain Ba9808-2-3 of Bacillus thuringiensis subsp. The microbial strain was a new strain of Bacillus thuringiensis subsp. Morrison Ba9008-2-3. (2) Culture medium: carbon source and nitrogen source are used as nutrient source. Among them, the carbon source can be starch, dextrin, glucose, maltose, etc.; the nitrogen source can be peptone, soybean cake powder, beef extract, corn steep liquor, etc. On this basis, add some other nutrients, such as salt, phosphate, potassium salt, calcium salt and so on. (3) Cultivation method: the microbial pesticide of the present invention can be cultivated by a liquid submerged fermentation method. The culture temperature is 27-30° C., the pH is 7-9, and the culture time is 25-40 hours. (4) Post-processing of the product: the culture solution is adjusted to a certain amount of spores, and then an appropriate amount of preservatives, emulsifiers, and UV protection agents are added to obtain the product. It is a pollution-free agricultural insecticide, which has special effects on important pests in vegetable production, such as ladybug physalis, flea beetle and small ape leaf beetle.

Description

A kind of microbial pesticide and preparation method thereof

technical field

The invention belongs to the technical field of microbial fermentation engineering, and relates to a microbial pesticide and a production method thereof.

Background technique

Pests and diseases cause huge losses to agricultural production every year. In order to achieve stable and high yields, people have mainly used chemical pesticides to control them. Chemical pesticides have the advantages of high control efficiency, fast speed, broad insecticidal and antibacterial spectrum, low cost, and simple use, so they have been developed rapidly and become an important means of preventing and controlling pests and diseases to win agricultural production. According to statistics, the ratio of the chemical control area to the total control area in my country from 1985 to 2002 was as high as about 95%. Due to the long-term, large-scale and repeated use of chemical pesticides, it has caused pollution to soil, water and the atmosphere; the increase in pesticide residues in agricultural by-products has also directly endangered human health and survival; at the same time, the resistance of pests and pathogens to pesticides has continued to deepen And expanding, at least 504 species of pests around the world have developed resistance to pesticides, and some pests have resistance up to tens of thousands of times; in addition, while chemical pesticides kill pests, they also kill natural enemies and other beneficial organisms, destroying ecological balance, causing more rampant pests. In this way, the application amount and frequency of pesticides have to be increased, thus causing a vicious circle of chemical pesticide application. For areas where the relationship between man and land is very tense, the only way out is to vigorously develop biological pesticides.

Contents of the invention

The purpose of the present invention is to overcome the shortcomings of the existing pesticides and provide a microbial pesticide and a production method thereof. The pesticide has the characteristics of high efficiency, safety, pollution-free and low production cost.

The microbial pesticide, its active strain (active ingredient) is the new bacterial strain Ba9808-2-3 of Bacillus thuringiensis subsp. Pests such as small ape leaf beetle and yellow striped flea beetle.

The preparation method of this microbial pesticide is as follows:

1. Identification of active strains

The serotype of the strain Ba9808-2-3 is H _8a8b. Through the identification of morphological characteristics, the vegetative body is a straight rod-shaped bacterial cell capable of producing spores. Flagella throughout the body, motile, Gram-positive. The biochemical reaction test, flagellar antigen analysis, cell antigen analysis, esterase electrophoresis analysis and other identification comparisons showed that it was similar to Bacillus thuringiensis subspecies Morrison. However, there are obvious differences in certain morphological characteristics. During the growth and reproduction process, parasporal crystals are not easy to see when they are formed in the sporangia, which is an important feature of the strain; and the released parasporal crystals are irregular, nearly Small square, 0.5-0.6×0.7 microns in size; colony shape, milky white, small, round, with smooth edges. The poisonous targets of this strain are also specific, mainly the Coleoptera pest Physalis physalis, the Chrysophyllidae pest Pythias japonica and the yellow-striped flea beetle. Therefore, the Ba9808-2-3 strain is a new strain of Bacillus tharingensis subsp.morrisoni.

2. Preparation process

(1) Production strains

The microbial strain used in the present invention is Bacillus thuringiensis Morrison subspecies new bacterial strain Ba9808-2-3, is preserved in China Microbial Strain Preservation Management Committee Common Microbiology Center, preservation number CGMCC No0920, preservation date is April 6, 2003 day.

(2) culture medium

The nutrient source in the culture medium adopts carbon source and nitrogen source. Among them, the carbon source can be starch, dextrin, glucose, maltose, etc.; the nitrogen source can be peptone, soybean cake powder, beef extract, corn steep liquor, etc. On this basis, add some other nutrients, such as salt, phosphate, potassium salt, calcium salt and so on.

(3) Culture method

The microbial pesticide of the present invention can be cultivated by liquid submerged fermentation. The cultivation temperature is 27-30° C., the pH is 7-9, and the cultivation time is 25-40 hours.

(4) Product post-processing

The culture solution is adjusted to a certain amount of spores, and then an appropriate amount of preservatives, emulsifiers and UV protective agents are added to form the product.

See the accompanying drawings for the specific process flow.

3. Insecticidal spectrum

The product was diluted to a solution with a spore content of 10 ⁶ cfu/ml, and the insecticidal spectrum test was carried out. The results are shown in Table 1. It can be seen from Table 1 that it is highly toxic to the young larvae of the important Coleoptera pests of the coleoptera, the physalis beetle and the young larvae of the flea beetle. The 10 ⁶ cfu/ml solution was used to correct the mortality after three days Both are 100%.

                                        Table 1 is the determination of the insecticidal spectrum of this microbial concentrated drug:

For testing Treatment Control Control Corrected death

Insect Dead Mortality Dead Mortality Rate

counting /%

Chrysomelidae

Lesser Ape Leafworm 45 100 3 6.7 100

Yellow-striped flea beetle 45 100 1 2.2 100

Curculionidae

Rice water weevil 16 33.3 5 11.1 25.0

Corn elephant 16 35.6 2 4.4 32.6

Ladybug family Coccinellidae

Physalis Ladybug 45 100 4 8.9 100

Bostrychidae

Grain Beetle 19 42.2 5 11.1 35.0

Pedidae Tenebrionidae

Red Grass Robin 18 40.0 3 6.7 35.7

Note: The number of tested worms is 45 for both the treatment and the control

Advantages of the invention

1. special effects

Most of the early Bacillus thuringiensis preparations were used to kill Lepidoptera pests. In recent years, some preparations for killing Coleoptera and other pests have been reported and developed. Toxic Bacillus thuringiensis preparations have not been reported.

2. Security

The insecticidal effect is achieved through crystal protein, which is a toxin source and non-toxic in itself. After eating, it is first digested by the strong alkaline (PH9-10) digestive juice in the insect intestine, the crystal structure is opened, and then activated by the activating enzyme in the intestine. Decomposes to form toxic proteins (toxin peptides), which act on midgut cells. Human and mammalian digestive juices are not strongly alkaline, and natural enemies and aquatic animals do not have the specific activating enzymes of pests, and neither can activate crystal proteins. Therefore, the preparation is very safe to humans, livestock, natural enemies of insects and aquatic animals.

3. Inexpensive

The producing bacteria have a high sporulation yield, and the production raw materials are common agricultural and sideline products, which are easy to obtain and are suitable for large-scale industrial production, and the production equipment can be used in common with other microbial products, so the cost is low.

Description of drawings

The accompanying drawing is a schematic diagram of the process flow

Detailed ways

Embodiment one: the preparation of this pesticide preparation with spore content of 10 billion/ml

In a 70L fermenter, a 50L culture medium was formulated with 2.5% of soybean cake powder, 1.0% of sweet potato starch rust, 1.0% of glucose, 0.05% of magnesium sulfate, and 0.5% of calcium carbonate. Cool to 30°C after sterilizing by conventional methods, inoculate the production strains at a ratio of 5%, and cultivate for 30 hours at 30°C ± 1 aeration to obtain a fermentation broth with a spore content of 6.2 billion/ml. The fermented liquid is concentrated by precipitation and then diluted into a suspension containing 10 billion spores/ml, and then added with 0.1% sodium benzoate as a preservative and 10% saponin as an emulsifier to obtain the product. The product has a spore content of more than 10 billion/ml, a suspension rate of 60-90%, a pH of 4.5-6.0, a fineness of 95% and a 100-mesh sieve, and a spore crystal ratio of 1:0.5.

Embodiment 2: Application test of using this microbial pesticide preparation to prevent and control eggplant Physalis ladybug

The test was carried out in a place in Ningbo, Zhejiang Province, using 200 times dilution of its 10 billion/ml preparation, the chemical pesticide control was 3000 times dilution of 50% phoxim emulsifiable concentrate, and a clear water blank control was set up, a total of 3 treatments. Each treatment area is 15m ² , each repeated 4 times, arranged randomly. 7 days after spraying, investigate 10 points for each treatment, 10 plants for each point, count the population base, and calculate the control effect. The results are shown in Table 2. As can be seen from Table 2, the 10 billion/ml 200-fold dilution of this preparation has a field control effect of 60.0% on Physalis ladybug, which is similar to the effect of the 3000-fold dilution of the chemical pesticide phoxim EC.

        Table 2 is the field control effect of the microbial pesticide preparations on eggplant physalis ladybug

Diluted medicine before the pest of the insect mouth/10 days after 7 days/10 plants/10 plants

Treatment Control Effect

Multiples Larvae Eggs Adults Larvae Eggs Adults

This microbial farmer

1:200 20 15 5 7 5 4 60.0%

medicine

1:3000 28 9 5 8 5 2 64.3%

Phoxim

Clear water / 45 16 2 45 0 10 /

Claims (2)

1. A microbial pesticide, characterized in that active bacterial strain is Bacillus thuringiensis Morrison subspecies new strain Ba9808-2-3. 2. a kind of preparation method that is specially used in the microbial pesticide described in claim 1, adopts microbial fermentation technology to produce, and the characteristic step of its preparation process is as follows: (1) Production strains The microbial strain used in the present invention is Bacillus thuringiensis subspecies Morrison new bacterial strain Ba9808-2-3; (2) culture medium The nutrient source in the medium adopts carbon source and nitrogen source, wherein the carbon source can be starch, dextrin, glucose, maltose, etc.; the nitrogen source can be peptone, soybean cake powder, beef extract, corn steep liquor, etc. Add some other nutrients, such as salt, phosphate, potassium salt, calcium salt, etc.; (3) Culture method The microbial pesticide of the present invention can be cultivated by a liquid submerged fermentation method, the cultivation temperature is 27-30°C, the pH is 7-9, and the cultivation time is 25-40 hours; (4) Product post-processing The culture solution is adjusted to a certain amount of spores, and then an appropriate amount of preservatives, emulsifiers and UV protective agents are added to form the product.