Experiment 26: Microbial culture characteristics
First, the basic principle Microbial culture characteristics refer to the population morphology and growth of microbial culture on the medium. Inclined, liquid and semi-solid media are generally used to test the culture characteristics of different microorganisms. They are cultured on slant medium and may be silky, bristly, beaded, sparse, dendritic or pseudo-rooted (Figure VII-6). It grows in a liquid medium and can be turbid, flocculent, mucous, forming a bacterial membrane, and the upper layer is clear and the bottom is precipitated. The puncture is cultured in semi-solid medium and can spread around the inoculation line; or only along the line; or the upper layer grows well, even into a piece, the bottom grows little; or the bottom grows well, the upper layer does not even grow. The use of microbial culture characteristics can be used as a reference for identifying and identifying whether or not pure culture is contaminated.
When testing the culture characteristics of microorganisms, or performing other microbiology experiments, the inoculation process must be ensured not to be contaminated by other microorganisms. To this end, in addition to the work environment requirements to avoid or reduce the contamination of bacteria as much as possible, skilled in mastering various sterility It is important to operate the inoculation technique.
Second, the equipment Bacillus subtilis, Escherichia coli, Staphylococcus aureus, Geo-trichum candidum (Bacillus mycoides), Serratia marcescens (Serratia marcescens);
Meat paste peptone slant medium, meat paste peptone liquid medium, semi-solid meat paste peptone medium, inoculating ring, inoculation needle, sterile pipette, alcohol lamp, etc.
Third, the operation steps
1. Inclined inoculation (1) On the meat paste peptone inclined test tube, write the name, date and vaccination of the inoculated bacteria with a marker.
(2) Ignite an alcohol lamp or a gas lamp.
(3) Hold the strain test tube and the beveled test tube to be inoculated with the thumb and forefinger, middle finger and ring finger in the left hand, and clamp the middle finger between the two test tubes so that the slope faces upwards and is leveled, as shown in Figure VII- 7. Loosen the tube stopper with your right hand on the side of the flame to facilitate extraction when inoculated.
(4) Take the inoculation ring in the right hand and sterilize it by flame burning (refer to experiment 1). Hold the cotton plug (or test tube cap) with the right hand palm edge and the little finger, the little finger and the ring finger respectively on the flame side, take it out, and quickly burn it. Nozzle.
(5) The sterile inoculation loop is inserted into the test tube of the strain, and the ring is first contacted with the inner wall of the test tube or the medium without the bacteria to achieve the purpose of cooling, and then a little lawn is picked. Exit the inoculating loop from the strain tube and quickly extend into the beveled tube to be inoculated. Use the ring to gently straighten from the bottom of the tube to the upper end of the tube. Do not cut the medium or make the ring contact the tube wall or nozzle. .
(6) The inoculation loop exits the beveled test tube, and then the tube is fired with a flame, and the test tube is stoppered at the flame side. Gradually bring the inoculating loop closer to the flame and then cauterize. If there are more bacteria on the inoculation ring, the ring should be baked on the flame and then cauterized, so as to prevent the unburned bacteria from splashing out of the polluted environment. Pay more attention to this when inoculation of pathogens.
2. When the liquid medium is inoculated into the meat paste peptone liquid medium, the operation procedure is basically the same as that when the inoculum is inoculated. The difference is that the inoculating loop of the picking liquid is placed in the liquid medium and should be on the liquid surface. Gently rub the inner wall of the tube to remove the bacteria from the ring, mix it into the liquid medium, plug the tube, shake the liquid, make the cells evenly distributed in the liquid, or mix with a tube shaker, such as Figure VII-8 shows.
When the inoculum is large or required to be inoculated into the liquid medium, the sterile water or liquid medium may be injected into the strain tube, the lawn is scraped off with the inoculating loop, and the strain suspension is quantitatively aspirated and added by a sterile pipette. Or pour directly into the liquid medium. If the species is a liquid culture, it can be added by a sterile pipette or directly into a liquid medium. Aseptic processing is required throughout the inoculation process.
3. Puncture inoculation pick the strain with the inoculation needle (the needle must be straight), puncture the semi-solid medium vertically from the center of the medium until it is close to the bottom of the tube, but do not penetrate, and then pull the needle along the original puncture line Plug the tube stopper and cauterize the inoculation needle as shown in Figure VII-9.
The aseptic operations of the above several inoculation methods, all of which are not described, are performed according to the first experiment. The tester should repeatedly practice the aseptic technique of inoculation until it is more skilled.
4. The inoculated slant, liquid and semi-solid medium were placed in a 28-30 ° C incubator, and the observation was taken after 2-3 days of culture.
Fourth, the experimental report
Contact: Ms. Sunny Wang
1. We have Good location
We`re located in the well known Ningbo International Port.
2. We`re Well-experienced
Tropical Group has many factories in the world, has 48 years experience in seafood export
3. We`re High quality assurance
Our company has passed HACCP, BRC, MSC, FDA, KOSHER and the other certifications.
4. We can do Best price
We are an industry and trade integration enterprise, which producing, packing and selling all by ourselves, greatly reducing the price difference caused by broker
5. We have Rich products
We have our own design department and R & D team, which can design personalized products according to customers' requirements.
6. We can do On-time delivery
Our products are exported to the United States, South America, Africa, Europe, Russia and other countries and regions. Company exports amounted to more than US$60 million in last year, enjoys high reputation in the aquatic products industry.
Sardines In Oil,Sardine Fillet In Oil,Sardines In Oil Canned,Canned Sardines In Oil
Tropical Food Manufacturing (Ningbo) Co., Ltd. , https://www.tropical-food.com