Many media are required for special purposes, such as for recognition, calculation, and the isolation of type-specific types of bacteria. For this purpose, a microbiologist based media sharing and application functions, as follows (Tarigan, 1988):
1. Selective media
This media can provide sufficient Nutrients for the growth of certain microbial species and can inhibit the growth of other microbes that are not expected to also grow on this medium. Selective media designed to suppress the growth of unwanted microbes and encourage the growth of unwanted microbes.
2. Differential Media
This media is used to grow certain microbes, and can Distinguished various types of microbes.
3. Media Tester (assay media)
This media is used to test vitamins, amino acids and antibiotics.
4. Port Calculation (Enumeration)
This media is used to calculate the number of bacteria present in a material.
Here are some types of media that is usually used in testing samples of food, beverages and traditional medicine in microbiology testing laboratories Balai Besar POM in Bandung:
a. EMBA (Eosin Blue Metilen order)
This media is used for the isolation of pathogenic Enterobacteriaceae such as Escherichia coli, Bacillus cereus, Salmonella and Enterobacter cloacae typimurium (Sudarsono.dkk, 2003). EMBA is a differential solid medium can be used to replace the Mac Conkey order (Tarigan, 1988).
Eosin and blue metilen serves to inhibit the growth of Gram-positive bacteria and Gram-negative bacteria. Metilen blue Eosin and also serves as an indicator of acid production (Tarigan, 1988). The composition of this medium consisted of (g / L):
- Pepton 10 - Lactose 5
- Sucrose 5 - Dipotasium hydrogen phosphate 2
- Eosin Y yellowish 0.4 - 0:07 Blue Metilen
- Agar-agar 13.5
b. Mac Conkey Brothers
This media is solid and differential media, which is used for the selection and growing Enterobacteriaceae and Gram-negative bacteria are rod-shaped. Content of bile salts and crystal violet in the medium can inhibit the growth of Gram-positive bacteria and Gram-negative (Tarigan, 1988).
This fluid contains lactose, when the degradation will produce acid and gas, which indicate the presence of Escherichia coli. The gas formed is collected in Durham tubes and formed acid was detected by using the purple bromokresol indicator turns yellow. Ox bile content of the medium can support the growth of non-bacterial Digestion. The composition of this medium consisted of (g / L):
- Pepton of casein 20 - 5 dried ox bile
- Lactose 10 - 0:01 purple Bromokserol
c. In order to Mannitol Salt
This medium is a medium containing 7.5% NaCl, which can inhibit the growth of most bacteria. This medium also contains mannitol, phenol red as pH indicator, is useful to detect the existence of acid produced by Staphylococcus that can ferment mannitol. Staphylococci ferment mannitol that can result in a yellow zone around the growth, while not able to ferment mannitol, will not cause color changes in the media (Tarigan, 1988).
d. Selenite Cystine Brothers (SCB)
This media is used for enrichment and isolation of Salmonella species from specimens such as urine and faeces (Tarigan, 1988). Sodium selenite is an inhibitor for bekteri coliform and Enterococcus in the first 6-12 hours of Incubation (Sudarsono.dkk, 2003). The composition of this medium consisted of (g / L):
- Pepton of casein 5 - L (-) Cystine 0:01
- Phosphate buffer 10-4 Sodium hydrogen selenite
- Lactose 4
e. Pepton Dillution Fluid (PDF)-Buffer
Is a solution to the diluent and sample homogenization. This fluid is rich in Nutrients that can increase the growth of bacteria. The composition of this medium consisted of (g / L):
- Pepton 10 - Disodium hydrogen phosphate dodecahidrat 9
- Sodium Chloride 5 - Potassium Dihydrogen Phosphate 1.5
f. Plate Count To (Casein-dextrose Yeast Pepton order)
This medium contains no inhibitors or indicators, are generally used to calculate the total microbes present in milk, water, and other materials. The composition of this medium consisted of (g / L):
- Pepton of casein 5 - D (+) glucose, 1
- Yeast extract 2.5 - To 14
g. Baird-Parker To (Staphylococcus Selective To Base acc. To Baird-Parker).
This medium contains lithium chloride and telurit to inhibit the growth of microbial flora. Whereas pyruvate and Glycine selectively stimulate the growth of microbes only in this case Staphylococcus. Staphylococcus colonies are characterized by a zone and the ring formed. This form is the result of proteolysis and lipolisis and the reduction of the tellurium telurit that produces shiny black colonies (Sudarsono.dkk, 2003). The following is a composition which is listed on the bottle BPA medium (g / l) are:
- Pepton of casein 10 - Glycine 12
- Extract the meat from 5 to 5 Lithium Chloride
- Yeast extract 1 - agar-agar 15
- Sodium pyruvate 10 - Egg-yolk telurit 50 ml
- Sulfametazin 0:05 g (If necessary)
h. To TCBS (sucrose Thiosulfate Citrate Bile order)
Used for isolation and selective medium for Vibrio cholerae. High concentrations of thiosulfate and citrate, and a strong base in the medium inhibits the growth of Enterobacteriaceae. Ox bile and cholate suppress the growth of Enterococci. Mixed bromtimol indicators timol blue and blue change the color to yellow when acid is formed even though the medium is a strong base (Sudarsono.dkk, 2003). The following is a composition which is listed on the bottle TCBS medium (g / l) are:
- Pepton of casein 5 - sucrose 20
- Pepton of meat 5 - sodium chloride 10
- Yeast extract 5 - Iron (III) citrate 1
- Sodium Citrate 10 - 0:04 Blue Timol
- Sodium thiosulfate 10 - 0:04 Blue Bromtimol
- Ox bile 5 - so-so 14
- Sodium Cholate 3
i. Bismuth Sulfite To acc. To Wilson-Blair (BSA)
This media is used to Isolate and differentiation of Salmonella typhi and other Salmonella. Brilliant green and bismuth are used to inhibit the growth of the bacterial flora. Colonies of Salmonella positive H2S showed black color caused by the formation of iron sulfide. Reduction of bismuth Ions to metallic bismuth raises the sparkling color around the colonies (Sudarsono.dkk, 2003). The composition of this medium consisted of (g / L):
- Pepton of meat 10 - bismuth sulfite indicator 8
- Extract the meat 5 - Iron (III) sulfate 0.3
- D (+) glucose, 5-4 disodium hydrogen phosphate
- Agar-agar 15 - Roya green 0025
j. For SPS (Sulfite Polymyxin Sulfadiazine order / perfringens Selective order)
This medium contains a broad spectrum of Nutrients. Sulfite reduced by Clostridia into sulfide, which reacts with iron and lead citrate black colony. Other microbes that reduce sulfite inhibited by the polimiksin and sulfadiazine. The composition of this medium consisted of (g / L):
- Pepton casein 15 - Sodium sulfite 0.5
- Yeast extract 10 - Iron (III) citrate 0.5
- Polimiksin B sulfate 0:01 to 0:12 Sodium sulfadiazine
- Agar-agar 13.9
k. Lactose Brothers
This media is used to test coliform bacteria, especially Escherichia coli. The use of lactose is indicated by the formation of gas. This gas will then be collected through a tube of Durham (Sudarsono.dkk, 2003). The composition of this medium consisted of (g / L):
- Pepton 5 - Lactose 5
- Extract the meat 3
l. Vogel for Johnson, Base
This media is used for a positive test for Syaphylococcus mannitol. Growth of other bacteria that grow inhibited by tellurite, lithium chloride, and Glycine concentration. Mannitol degraded to acid by Staphylococcus pathogens, the reaction is characterized by the phenol red changes color to yellow. Pathogen Staphylococcus telurite also reduce the metal tellurium, which causes black colonies (Sudarsono.dkk, 2003). The composition of this medium consisted of (g / L):
- Pepton of casein 10 - D (-) mannitol 10
- Yeast extract 5 - Dipotassium hydrogen phosphate 5
- Lithium chloride 5 - Glycine 10
- Phenol red 0025 - To 13
- Potassium telurit
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