How to isolate and screen microorganisms with bacteriostatic function from soil Design isolation pro

Isolation and screening of microorganisms with bacteriostatic functions from soil requires a series of experimental steps. Here's a basic design solution:

1.*Soil sample collection**: Selecting soil samples from different places and at different times can ensure the diversity of samples. Samples are collected from different soil depths with a sterile plastic spatula and collected into a sterile sample bag.

2.Isolation of soil microorganisms: Soil samples are processed to isolate microorganisms.

First, remove stones and plant tissues from the soil, then add a certain amount of sterile water to dilute the soil and mix well. After that, through a series of dilution steps, the microorganisms in the soil are dispersed into individual cells. Finally, the dispersed microorganisms are inoculated on a specific medium by plate coating or dilution coating.

3.*Culture of microorganisms**: The inoculated medium is incubated in a constant temperature incubator for a period of time (determined by the growth rate of the microorganisms) to allow the microorganisms to grow and form visible colonies.

4.*Screening of strains**: Screening of strains with antibacterial function through antibacterial experiments.

You can choose to conduct antibacterial experiments on common pathogenic bacteria such as Escherichia coli and Staphylococcus aureus. The strains to be tested were inoculated on the same medium as these pathogens, and the size of the inhibition zone was observed and recorded.

5.*Identification of antibacterial ability**: The size of the antibacterial circle can reflect the antibacterial ability of the strain to be tested. The larger the inhibition zone, the stronger the bacteriostatic ability of the species. At the same time, the antibacterial ability can be quantitatively expressed by measuring the diameter or area of the antibacterial zone.

6.*Preservation of strains**: In order to preserve these strains with antibacterial function for a long time, glycerin tube storage method or sand tube storage method can be used.

This protocol is only a basic isolation screening process, and the specific protocol may be adjusted according to the specific research objectives and experimental conditions. At the same time, this protocol needs to be carried out under strict laboratory conditions to ensure aseptic operation and prevent contamination by bacteria.

1. First of all, it is necessary to clearly prepare for screening spectrum or narrow spectrum of bacteriostatic microorganisms, and secondly, you must select your indicator bacteria 2. Generally, the transparent circle method is used to screen the antibacterial microorganisms Steps: 1. Sterilization of culture medium and Oxford cup; 2. After the medium is cooled to the temperature of the indicator bacteria that does not scald to death, add about 2% of the indicator bacteria 3 to it, mix evenly and pour the plate 4, flat.

Summary. Screening usually uses the microbial pure culture method, and the agar culture plate is used to scribble and separate, and the single bacteria are obtained and then combined antibacterial experiments.

Screening for antimicrobial activity from metabolites of pure cultures isolated from soil.

Generally, the transparent circle method is used for the screening of bacteriostatic microorganisms.

The steps are as follows. Sorry, I designed an experiment based on this.

Good. Use the agar diffusion method.

1. Collect fungus samples. 2. Enrichment culture. 3. Purebred separation. 4. Performance measurement.

This is how to get a pure culture, and then how to screen out the strains with his antimicrobial activity.

Pick a single colony on a medium plate for scribing transfer screening culture.

Screening usually uses the microbial pure culture method, and the agar culture plate is used to scribble and separate, and the single bacteria are obtained and then combined antibacterial experiments.

Can you please elaborate on the process? The topic is how to screen for antimicrobial activity strains by agar diffusion and explain the experimental procedure.

The antimicrobial active strains were screened by agar diffusion method, and the experimental procedure was described.

1. Activation culture of indicator bacteria, dilute indicator bacteria, add to the upper medium, and pour the upper medium onto the lower plate.

2. Punching. 3. Add the product to be tested in the well. 4. Upright culture until the inhibition zone appears.

Screening usually uses the microbial pure culture method, and the agar culture plate is used to scribble and separate, and the single bacteria are obtained and then combined antibacterial experiments.

Summary. 1.Use of soil ** substances and selection of specific functional microorganisms:

Nutrient culture methods can be used to screen for functional microorganisms in specific media and which types of media can meet the proliferation and activity of specific functional microorganisms. 2.Establishment of national in-situ screening technology:

In the national in situ determination, functional microorganisms can be classified and screened by factors such as culture conditions, applied soil treatment methods, etc. 3.Utilizing species-specific molecular flow cytometry:

Species-specific molecular flow cytometry can also be used to selectively screen for functional microorganisms and to characterize functional microorganisms using morphologically specific patterns. 4.Applied Whole Genome Sequencing Technology:

Whole-genome sequencing can also be used to identify functional microbial populations for certain functional microbial taxa, thereby identifying functional microbial species.

To design an experiment.

1.Use of soil substances and selection of specific functional microorganisms: Functional microorganisms can be screened in specific media with or using nutrient culture, and which types of media can meet the requirements of proliferation and activity of functional microorganisms that are perturbed by specific organisms.

2.Establish a national in-situ screening technology: In the national in-situ determination, functional microorganisms can be classified and screened by factors such as culture conditions, soil treatment methods, etc.

3.Species-specific molecular flow cytometry: Species-specific molecular flow cytometry can also be used to selectively screen for functional microorganisms, and morphologically specific patterns can be used to identify and characterize functional microorganisms.

4.Application of whole-genome sequencing technology: Whole-genome sequencing technology can also be used to determine which species are functional, and thus to discover functional microbial species for certain functional microbial groups.

Design an experiment.

How to screen functional microorganisms in soil Design an experiment.

Screening of functional microorganisms1Species detection: firstly, species detection was carried out, PCR technology was used for nucleic acid amplification, and metagenomic analysis was carried out to detect the microbial species composition in the soil. 2.

Ternary electrochemical activity analysis: The ternary electrochemical balance delay learning device is used to judge the activity of microbial function. 3.

Gene expression analysis: RNA sequencing technology was used to detect the activity and expression level of specific genes of soil microorganisms to find out functional microorganisms. 4.

Luciferase reporter gene test: Luciferase analysis is used to detect active microorganisms in the soil, as well as genes or metabolism related to their activity. 5.

Biological function analysis: elemental, biochemical and molecular ecological methods are used to analyze the functional microorganisms in the soil, such as biological activity analysis, using a certain biological activity test tube to detect the carbon and nitrogen utilization ability, nutrition ability and tolerance ability of microorganisms; Enzyme functional ecological analysis, detection of microbial metabolism characterization; Amino acid metabolism analysis to reveal the characteristics related to amino acid metabolism of functional microorganisms.

The following is an example of an experimental protocol designed to isolate and screen antibiotic-resistant microorganisms from soil:

Objective: To screen microorganisms with antibiotic resistance characteristics from soil samples.

Protocol Procedure: Sample Collection and Processing:

a.Choose from different** soil samples, such as farmland, parks, or meadows.

b.Collect soil samples with sterilized tools and store them in a dry, sterile container.

c.Each soil sample is made into a suspension, and a homogeneous soil suspension is obtained by adding a suitable buffer (e.g., normal saline) and shaking mixing.

Dilution & Separation:

a.Serial dilutions are performed on the soil suspension to obtain the appropriate number of colony-forming units (CFUs).

b.Using the plate counting method, evenly coat the diluted soil suspension on agar plates containing nutrients and appropriate antibiotics.

c.Use sterile cotton swabs to divide soil samples onto different plates to avoid cross-contamination.

d.Under appropriate conditions, plate culture in a thermostatic incubator to promote microbial growth.

Antibiotic Selection:

a.Choose agar plates with different types of antibiotics. Can include broad-spectrum and specific classes of antibiotics.

b.Transfer a single colony from the plate from the previous step to a new agar plate containing the corresponding antibiotic.

c.Incubate these plates in a thermostatic incubator and observe for colony growth.

Colony identification: aSelect colonies that demonstrate tolerance and isolate them to extract pure cultures.

b.Routine microbiological experiments such as morphological observation, Gram staining, physiological and biochemical tests, etc., are performed to determine the characteristics of the strains.

c.It can enable Sakufantan to identify and classify the screened strains using molecular biology techniques, such as 16S rRNA gene sequencing.

Analysis of results: aThe number and variety of strains with antibiotic resistance properties were recorded.

b.Perform statistics and analysis to understand the distribution and diversity of antibiotic-resistant microorganisms.

Experimental Notes:

All experimental procedures should be performed under sterile conditions to avoid external contamination.

Pay attention to the use of personal protective equipment, such as lab gloves and masks, to ensure safe handling.

Use antibiotics appropriately and dispose of laboratory waste in accordance with relevant regulations and ethical guidelines.

process. Isolation and screening of excellent saccharification enzyme strains.

Melt the medium, pour the plate, break up the spore pellets, dilute the gradient, coat the plate, culture observation, add iodine solution dropwise, pick colonies, inoculate, culture, saccharification enzyme activity determination, and preserve the strains.

Isolation of lactic acid bacteria from sour dairy products.

Preparation of culture medium, inverted plate, serial dilution, coating plate, culture observation, picking colonies, connecting milk ducts, culture observation, subculture, selection of curd tubes, lactate determination, and preservation of cultures.

5 steps. Isolation and screening of excellent saccharification enzyme strains.

1) Melt the starch Cha's medium, and pour several plates and slopes after a little cooling.

2) Take a little seed koji, add 10ml of sterile normal saline triangular flask with glass balls, and shake vigorously to disperse the spore pellets to form a uniform spore suspension particle. It is then filtered with sterile gauze in a sterile test tube.

3) The above filtrate was released to 10-7 by 10-fold dilution method, and each of the last 3 dilutions was taken and coated with 2 to 3 dishes in turn with a sterile coater on the starch Cha's medium plate, and 30 cultured for 1 2d

5) Performance assay: Determine the saccharification enzyme activity of each colony.

Isolation of lactic acid bacteria from sour dairy products.

1) Prepare BCG bovine milk nutrient agar medium.

Weigh 10g of skimmed milk powder, dissolve it in 50ml of water, add bromocresol green alcohol solution, and sterilize under pressure for 20min

Take another 2g of agar, dissolve it in 50ml of water, add 1g of yeast paste, adjust the pH value after dissolving, and sterilize under pressure for 20min

Mix the above two solutions with aseptic operation while hot, pour 6 plates, wait for solidification, and put 37 cultures for 24h, if there is no growth of miscellaneous bacteria, it can be used.

2) dilute the sample to 10-7 by 10-fold dilution method, take each of the dilutions of -6 2 dilutions, respectively placed on the above-mentioned nutrient plates, coat 2 to 3 dishes in turn with a sterile coater, and place 43 cultures for 48h.

3) Transfer the typical colonies to the skim milk fermentation tube, 43 culture for 8 24h, if the milk tube is coagulated, no bubbles, acidic, microscopic examination of the cell rod or splink, Gram staining is positive, then it will be passed several times in a row, 43 culture, select the milk duct that can coagulate in 3 4h, and keep it for later use.

4) Identification of lactic acid bacteria and determination of biomass.

Instructors: Fan Lijuan, Wu Pengxia, Zhang Wenqing, etc.

The soil contains a large number of microorganisms, and a tablespoon of soil microorganisms can reach hundreds of millions, so how can the small microorganisms that are invisible to the naked eye be separated from the soil? On the morning of January 8, more than 60 members of the Urban Environmental Protection Beauty Club and the Life Science Park Club walked into the microbiology laboratory of Jiyuan No. 1 Middle School and experienced the whole process of isolating microorganisms from the soil.

Fan Lijuan, the tutor of the urban environmental protection beauty club, explained the experimental steps and precautions to everyone.

In order to carry out the experiment smoothly, we have made full preparations, look at the experimental procedures and simple knowledge points of the dry stool we wrote, is it very detailed and neat?

At the beginning of the experiment, we will study the experimental process together.

You say the steps, I will operate, unite and cooperate to do things.

Carefully weigh the drug and configure the medium.

The medicine is weighed and begins to heat and melt.

The teacher said that the agar will not melt until 98°C, so we need to heat it up for a while!

Add water to set the volume. The medium is prepared and sterilized in an autoclave.

Take advantage of the gap of sterilization and grasp the gradient dilution.

This pipette is slippery, and it's really hard to operate for the first time!

Pour the plates. Looking at the tablet he had poured, his heart was full of pride.

Teacher Wu Pengxia demonstrated the single colony marking method.

The inoculation loop is burned first and sterilized.

The scribing must be gentle and steady, and the medium must not be broken.

Hands-on drawing and practice.

If you do it yourself, you will be happy.

After drawing the plate, wait for it to be incubated in the incubator, and after two days, small bacterial colonies will grow on the plate.

The experiment went very smoothly, and Mr. Zhang Wenqing of the laboratory was very happy and rewarded everyone for visiting the fermentation room, ** the fruit wine and fruit vinegar stored in the laboratory.

Open the lid and smell it, it really smells of vinegar!

Mr. Zhang also let everyone visit the model room and the herbarium room.

Teacher Fan Lijuan told everyone about the school model making competition.

The models made by the senior brothers and sisters are really good, and we will definitely make better works in the future, and put them here.

Seeing animal specimens for the first time, many students were amazed and gained a lot of knowledge.

At the end of the experiment, seeing how clean the experimental table we cleaned up, Mr. Zhang praised us several times and encouraged everyone to go to the laboratory often to do experiments, and he will definitely fully cooperate. What a dedicated and loving Mr. Zhang, we admire him and thank him from the bottom of our hearts!

After two days of culture, the bacteria we coated grew out, and looking at the small colonies growing on the plate, I felt a sense of accomplishment!

The effect of slab marking is not ideal, but through practical operation, we have firmly remembered the specific steps, and I believe that it should not be too wrong to do relevant exercises in the future!

Accidentally contaminated the mold that grew, and the teacher said that it was mucor, and it would be used in the next semester to make fermented bean curd. Looking at this fluffy white mucormycophae, we are looking forward to the next semester's course.