INTRODUCTION
A growth medium or culture medium is a liquid or gel designed to support the growth of microorganisms or cells, or small plants. There were different types of culture media for different types of cell growing. It is depends on the culture in the experiment used. There are two major types of growth media: those used for cell culture, which use specific cell types derived from plants or animals, and microbiological culture, which are used for growing microorganisms, such as bacteria or yeast. The most common growth media for microorganisms are nutrient broths and agar plates; specialized media are sometimes required for microorganism and cell culture growth. In this experiment both agar and the nutrient broth are been prepared.
An agar plate -- an example of a bacterial growth medium.
Autoclaving is one of the techniques in the heat sterilization. An autoclave is an instrument used to sterilize equipment and supplies by subjecting them to high pressure saturated steam at 121 °C for around 15–20 minutes depending on the size of the load and the contents. Autoclaving uses steam under high pressure. Autoclaving is the most effective and most efficient means of sterilization.
Autoclave in laboratory
DISCUSSION
In this experiment we need to prepare our own culture media. The most common growth media for microorganisms are nutrient broths (liquid nutrient medium) or LB medium (Lysogeny Broth). Liquid media are often mixed with agar and poured into Petri dishes to solidify. These agar plates provide a solid medium on which microbes may be cultured. They remain solid, as very few bacteria are able to decompose agar. Bacteria grown in liquid cultures often form colloidal suspensions . For our broth in this experiment we used :
0.6 g/L "Lab- lemco" powder (a beef extract)
0.4 g/L yeast extract
1.0 g/L peptone (a nitrogen source)
1.0 g/L sodium chloride
3.0 g/L agar powder
Nutrient agar is a microbiological growth medium commonly used for the routine cultivation of non-fastidious bacteria. It is useful because it remains solid even at relatively high temperatures. Also, bacteria grown in nutrient agar grows on the surface, and is clearly visible as small colonies. In nutrient broth, the bacteria grows in the liquid, and is seen as a soupy substance, not as clearly distinguishable clumps. The distilled water is used for pH adjustment. Peptones are derived from animal milk or meat digested by proteolytic digestion. In addition to containing small peptides, the resulting spray-dried material includes fats, metals, salts, vitamins and many other biological compounds. Peptone is used in nutrient media for growing bacteria and fungi.
1.0 g/L sodium chloride
3.0 g/L agar powder
Nutrient agar is a microbiological growth medium commonly used for the routine cultivation of non-fastidious bacteria. It is useful because it remains solid even at relatively high temperatures. Also, bacteria grown in nutrient agar grows on the surface, and is clearly visible as small colonies. In nutrient broth, the bacteria grows in the liquid, and is seen as a soupy substance, not as clearly distinguishable clumps. The distilled water is used for pH adjustment. Peptones are derived from animal milk or meat digested by proteolytic digestion. In addition to containing small peptides, the resulting spray-dried material includes fats, metals, salts, vitamins and many other biological compounds. Peptone is used in nutrient media for growing bacteria and fungi.
The preparation of the nutrient agar.
Autoclaves use pressurized steam to destroy
microorganisms, and are the most dependable systems available for the
decontamination of laboratory waste and the sterilization of laboratory glassware,
media, and reagents. Higher temperature in autoclaving ensure that more rapid killing for the microorganisms. In autoclave, for efficient heat transfer, steam must flush the
air out of the autoclave chamber. Before using the autoclave, check the drain
screen at the bottom of the chamber and clean if blocked. If the sieve is
blocked with debris, a layer of air may form at the bottom of the autoclave,
preventing efficient operation. For efficient heat transfer, steam must flush the air out of the autoclave chamber. If the drain screen is blocked with debris, a layer of air may form at the bottom of the autoclave and prevent proper operation. The most important things is to make sure that the door is sealed before selecting the cycle.
Nutrient agar that will undergoing autoclaving.
CONCLUSION
In this experiment we had determined the correct ways to prepare a culture media use in microorganisms growing. We had weight the substances in the nutrient agar. During the experiment, we had taken few steps of sterilization to avoid contamination for our growth media.
REFERENCES
No comments:
Post a Comment