Microbial culture

, vaccination

microorganisms
to the artificial
culture
-based or living organisms suitable for its growth and reproduction process is called inoculation.
the most used vaccination tools in the laboratory are vaccination rings and vaccination needles. Because of the different vaccination requirements or methods, the needle tip of the vaccination needle is often made into different shapes, there are knife-shaped, tweezers and so on. Sometimes dropper and straw can also be used as a vaccination tool for liquid inoculation. In solid
,
be used when applying the liquid evenly to the surface of the solid culture. (Figure 1)Figure 1 Vaccination and separation tool
Inoculation needle 2. Vaccination ring 3. Inoculation hook 4.5. Glass stick 6. Inoculation ring 7. Inoculation ring 8. Small anatomical knife
The following are commonly used vaccination methods:
1) line vaccination This is the most commonly used vaccination method. That is, on the solid culture base surface for a straight-forward movement back and forth, you can achieve the role of inoculation. Commonly used vaccination tools are vaccination rings, vaccination needles, etc. This method is commonly used in bevel inoculation and flat-panel dashing.
2) Three-point vaccination is commonly used in the study of mold forms. This method is to inoculate a small number of microorganisms on the surface of the plate, into three points of isomehial triangles, so that each independent formation of bacteria backward, to observe and study their form. In addition to three points, there are one or more vaccinations.
3) Puncture inoculation is often used to preserve anaerobic strains or to study microorganisms. When you do puncture vaccination, the vaccination tool used is the vaccination needle. The culture base used is generally a semi-solid culture base. It is done: with inoculation needles to extract a small number of strains, along the semi-solid culture center to the bottom of the tube for a straight puncture, if a bacterium has whiplash and can move, can grow around the puncture line.
4) The method of pouring and inoculation is to put the microorganisms to be received first into a petri dish, and then poured into a solid medium cooled to about 45 degrees C, quickly and gently shake, so that the bacteria liquid to achieve the purpose of dilution. After the plate solidified, culture at a suitable temperature, you can grow a single microbial microbial bacterios.
5) coating inoculation and watering inoculation slightly different, that is, first pour the plate, let it solidify, and then pour the bacteria liquid into the plate, quickly with the coating stick on the surface for back and forth coating, so that the liquid evenly distributed, you can grow a single microorganism.
6) Liquid inoculation It can be called liquid inoculation by washing the bacteria from a solid medium, pouring them into a liquid medium, or by connecting the bacteria fluid to the liquid medium with a pipet, or by moving the bacteria from a liquid culture to a solid medium.
7) Vaccination Is the method of injecting the waiting microorganisms into living organisms, such as humans or other animals, the common vaccination, is to use injection, access to the human body, to prevent certain diseases.
8) Live inoculation is a method specifically designed to culture viruses or other pathogenic microorganisms, as viruses must be inoculated in living organisms to grow and reproduce. The living body used can be an entire animal, or it can be an ionospheric tissue, such as a monkey kidney, or it can be a developing chicken embryo. Vaccination can be given by injection or mixed feeding., separation purification
contains more than one microbial culture called mixed culture. If all cells in a bacteria come from a progeny cell, the cell is called pure culture. Microbes used in the identification of strains generally require pure cultures. The process of obtaining pure culture is called separation purification, and there are many methods.
1, pour flat method
first of all, the microbial suspension through a series of dilution, take a certain amount of dilution and melt good to maintain at about 40 to 50 degrees of nutrition
agar fat
medium fully mixed, and then pour this mixture into a sterile petri dish, to be solidified, the plate upside down in a constant tank culture. A single cell after multiple proliferation to form a colony, take a single colony into suspension, repeat the above steps several times, you can get pure culture. (Figure 3,a)Figure 3 Pouring plate method (a) Coating flat plate method (b) Illustration
1. Bacterial suspension 2. Melting culture base 3.culture 4.sterile water
2, coating flat plate method
First, the microbial suspension through appropriate dilution, take a certain amount of dilution on the sterile solidified nutritional agar plate, and then use a sterile glass scraper to apply the dilution evenly on the surface of the culture base, cultured by
stration
can get a single bacterios. (Figure 3-5,b)3, plate dashing method
the simplest method of separating microorganisms is flat dashing method. Use sterile inoculation rings to pick up a small number of cultures and line them on the plate. There are many methods of dashing, the common more easy to appear a single bacteragial dash method has slash method, curve method, square method, radiation method, four-grid method and so on. (Figure 4) When the inoculation ring moves back on the surface of the culture base, the bacteria on the inoculation ring gradually dilute, and finally disperse a single cell on the line, cultured, each cell grows into a bacteria. (Figure 4)methods and principles of the
and the method and principle of the rich culture method are very simple. We can create conditions in which only the desired microorganisms can grow, where the microorganisms needed can effectively compete with other microorganisms and outpace other microorganisms in terms of growth capacity. Conditions created include the selection of the most suitable carbon source, energy, temperature, light, pH, permeable pressure and hydrogen subjects. Under the same culture base and culture conditions, after repeated species transfer, the last rich strains can easily grow monobacteria on solid cultures. If some specialized parasitic bacteria are to be isolated, samples must be inoculated into the corresponding sensitive host cell population to grow in large quantities. Pure parasitic bacteria can be obtained by repeatedly transferring the species.4 Flat Dash Separation
1. Slash method 2. Curve method 3. Square method 4. Radiological method 5.four-gram method 5, anaerobic method
in the laboratory In order to isolate certain anaerobic bacteria, the test tube containing the original medium can be used as a culture container, the test tube in boiling water 0 bath
heat
for several minutes, in order to evict the dissolved oxygen in the medium. Then cool down quickly and inoculated. After inoculation, sterile paraffin is added to the surface of the culture base, which is isolated from the air. Alternatively, after inoculation, the gas in the culture base is replaced by N2 or CO2, and the test tube port is sealed on the flame. Sometimes, in order to isolate certain anaerobic bacteria more effectively, the isolated samples can be inoculated on a medium and the petri dish placed in a fully sealed anaerobic culture unit., the growth of cultured
microorganisms, in addition to its own genetic characteristics, but also by a number of external factors, such as nutrient concentration, temperature, moisture, oxygen, pH and so on. The types of microorganisms vary, and the way and conditions of culture vary.1, the factors that affect the growth of microorganisms
the growth of microorganisms, in addition to their own genetic characteristics, but also by many external factors. There are many factors that affect the growth of microorganisms, as outlined below.1) Nutrient concentration
The growth rate of bacteria is related to the concentration of nutrients: μ smax s/(K s) the relationship curve between nutrient concentration and growth rate is typical bi curve.
K value is a very basic characteristic constant of bacterial growth. Its value is small, indicating that the nutrient concentration required by bacteria is very low, so in nature they grow everywhere. However, when nutrition is too low, bacteria can have difficulty growing and may even die. This is because in addition to the energy needed to grow, bacteria also need energy to sustain it. This energy is called maintenance energy. On the other hand, with the increase of nutrient concentration, the growth rate is closer to the maximum.2) Temperature
In a certain temperature range, each microorganism has its own growth temperature of three basis points: the minimum growth temperature, the most suitable growth temperature and the highest growth temperature. Microbes can grow at three-base points of growth temperature, but at different rates. Microorganisms only grow at the most suitable growth temperature, the fastest growth rate, the shortest generation time. Beyond the minimum growth temperature, microorganisms do not grow, the temperature is too low, and may even die. Beyond the maximum growth temperature, microorganisms should also stop growing, the temperature is too high. Will also die. In general, the growth temperature of each microorganism is constant at three basis points. But it is also often affected by other environmental conditions.
Depending on the most suitable growth temperature of microorganisms, they can be divided into three types:
a. cold-addicted microorganisms: most of which are moderate growth temperatures between -10 degrees C-20 degrees C
b. moderate temperature microorganisms: their most suitable growth temperature is generally between 20 degrees C and 45 degrees C
c.3) Moisture and
are necessary conditions for microorganisms to grow. Spores, spores germinate, first of all, need water. Microbes cannot survive without water. But microorganisms can only grow in aqueous solutions, not in pure water. All kinds of microorganisms have small and appropriate water activity areas in the range of water activity that cannot grow and develop.4) Oxygen
according to the needs of microorganisms for oxygen, they can be divided into the following five types.
a. Oxygen-demanding microorganisms: These microorganisms need oxygen for breathing. You can't grow without oxygen, but high concentrations of oxygen are also toxic to oxygen-demanding microorganisms. Many oxygen-demanding microorganisms cannot grow when oxygen concentrations are greater than those in the atmosphere. The vast majority of microorganisms fall into this category.
b. Co-oxygen-demanding microorganisms: These microorganisms can grow when there is oxygen or no oxygen, but the metabolic pathways are different. In the presence of no oxygen, it fermentation, such as yeast anaerobic ethanol fermentation.
c. trace oxygen-demanding microorganisms: these bacteria need oxygen, but only grow at 0.2 atmospheric pressure is the best. This may be caused by an enzyme that contains ineration under strong oxidation conditions and therefore only works at low pressure.
d. Oxygen-resistant microorganisms: These microorganisms do not need oxygen to grow, but they are not afraid of its presence and will not be killed by it.
e.. Anaerobic microorganisms: These microorganisms do not require molecular oxygen during growth. The presence of molecular oxygen poisons their growth, either suppressed or killed.2, culture method
1) according to the need for oxygen at the time of cultivation, can be divided into aerobic culture and anaerobic culture two categories.
aerobic culture: also known as "good air culture." That is to say, this microorganism needs oxygen to be added when cultured, otherwise it cannot grow well. In the laboratory, bevel culture is used to obtain sterile air from the outside world through cotton plugs. The triangular flammable liquid culture is mostly oscillating through the shaker, allowing the outside air to flow into the bottle.
anaerobic culture: also known as "anaerobic culture." This type of microorganism does not require oxygen to participate in culture. In the culture of anaerobic microorganisms, the most important thing is to remove oxygen from the culture base. The following methods can generally be used:
a. Reduce the redox potentiary in the medium: often reduce the agent such as glutathione, sulfur-based acetate, etc., added to the medium, you can achieve the goal. Some animals of dead or living tissues such as bovine heart, sheep brain into the medium, can also be suitable for the growth of anaerobic bacteria.
b. Oxygenation: There are also many methods, mainly: absorbing oxygen with coke-free acid, absorbing oxygen with phosphorus, absorbing oxygen with a mixture of aerobic bacteria and anaerobic culture, absorbing oxygen with seeds that grow from plant tissues such as germination, and deoxygenation by producing hydrogen and oxidation.
c. Isolated oxygen: deep liquid culture; sealed with paraffin oil; semi-solid puncture culture.
d. Substitute oxygen drive oxygen with two oxygen carbons, nitrogen for oxygen, oxygen by vacuum, hydrogen for oxygen, and mixed gas for oxygen. 2) According to the physical state of the culture base, it can be divided into solid culture and liquid culture.
solid culture: it is a method to carry out microbial culture under the right conditions by connecting the bacteria to a loose and nutritious solid medium.
: In the experiment, liquid culture can make microorganisms multiply rapidly, obtain a large number of cultures, under certain conditions, or microorganisms choose an effective way to increase bacteria. 4. The preservation of
species of commonly used strain preservation method often uses
drying
, low temperature and air isolation measures to limit its metabolism to the lowest range, so that its life activity is in a semi-permanent dormant state, so that the species can survive, do not pollute germs, do not occur or less mutation, preserve the original variety of biological characteristics of the species. commonly used species preservation method has slope or semi-solid generation preservation method, as well as frozen vacuum drying method and liquid nitrogen ultra-low temperature preservation method. Others still have carrier preservation method and suspension preservation method. 1. Slant or semi-solid transmission preservation method
the commonly used culture base of this method of preservation bacteria species is common broth agar slope,
serum
sloping surface, blood agar slope, egg slope and serum broth semi-solid culture base and so on. On beveled or semi-solid culture base surfaces, sterilized liquid paraffin is often added to isolate air. In addition, the transmission of anaerobic bacteria preservation is often the use of sore meat base. 2. The frozen vacuum
will be frozen with a certain protective agent (e.g. sterile skimmed milk) and then vacuumed under freezing