Selective and enrichment media

What is culture media
Bacteria culture
Importance of culturing.
Culturing and medium.
History of culture media.
How many types of growth media .
Basic components of culture media.
Classification
Consistancy
Nutritional components
Functional use
Aseptic condittion .
General steps for preparation of culture media .
Selective media .
Enrichment media.
Storage of culture media.

1. Selective and enrichment media

2. SYNOPSIS What is culture media Bacteria culture Importance of culturing. Culturing and medium. History of culture media. How many types of growth media . Basic components of culture media. Classification Consistancy Nutritional components Functional use Aseptic condittion . General steps for preparation of culture media . Selective media . Enrichment media. Storage of culture media.

3. WHAT IS CULTURE MEDIA An artificial culture media must provide environment and nutional condition. A culture media contains water,nutritional elemennts and some growth factor. The ph of the medium must be set accordingly. Uses= Enrich the number of bacteria. Select for certain and supress other. Differentiate among different kinds of bacteria.

4. CULTURING OF BACTERIA A Microbial culture is a method of multipying microorganism. Microbial culture are used to determine the type of organism,its abundace in the sample being tested or both . MAIN PURPOSE Isolation of bacteria. To create antigen for laboratory. Culture bacteria for genetic study.

5. CULTURE AND MEDIUM CULTURE= It is term given to microorganism that are cultivate in the lab for the purpose of identification and studying. MEDIUM= IT is the term given to the combination of ingredients that will support the growth and cultivation of microorganism by providing all the essential nutrient required for the growth.

6. HISTORY OF CULTURE MEDIA Before the use of agar, attempts were made to use gelatin as solidifying agent, gelatin had some inherent problems . It existed as liquid at normal incubating temprature 35-37◦. HOW MANY TYPES OF GROWTH MEDIA= There are two major types of grwoth media- A= Cell culture B= Microbiology culture

7. BASIC COMPONENTS Nutrients -Energy source -carbon source -nitrogen source Mineral salts A suitable physical factor = temperature

8. CLASSIFICATION BACTERIA culture media can be divided in at least three ways A= Conistency B=Nutritional components C= Functional use

9. Classification based on consistency LIQUID MEDIA = There are available for use in test tube etc. Liquid media are some times referred as BROTHS. SOLID MEDIA= Agar is most commomly used. SEMI SOLID= Used in demonstrating bacterial mortility .

10. CLASSIFICATION BASED ON NUTRITIONAL COMPONENTS SIMPLE MEDIA = simple media such as pepton water, nutrient agar can support non fastidious bacteria. COMPLEX MEDIA= Complex media such as blood agar have ingredients whose exact components are difficult to estimate. SYNTHETHIS MEDIA= Especially prepared media for reseach purpose where the composition is well known.

11. CLASSIFICATION BASED ON FUNCTIONAL USE AND APPLICATION BASAL MEDIA ENRICHED MEDIA SELECTIVE MEDIA ENRICHMENT MEDIA DIFFRENTIAL MEDIA TRANSPORT MEDIA ANAEROBIC MEDIA

12. ASEPTIC CONDITION Sterile equipment and media are used during bacteria culture. Culture media and culture tubes are open for minimum time duration. All work done near the burner in laminar air flow banch .

13. GENERAL STEPS FOR PREPARATION Weight the media and mix in distilled water. Now transfer the the media in autoclave for 20 to 25 min at 15psi. Now inoculation is done. Incubate in cubator for 24 hours for colony growth.

14. SELECTIVE MEDIA They are designed to inhibit unwanted commensal or contaminating bacteria. Selective media are agar based.

15. EMB [ EOSIN METHYLENE BLUE AGAR ] It is selective for gram negative bacteria . Composition of EMB S.NO. COMPOUND VOL. IN 1000 ML 1 Peptone 10 gm 2 Lactose 10 gm 3 Potassium diphosphate 2 gm 4 Agar 15 gm 5 Eosin 4 .4 gm 6 Methylene blue .065 gm

16. PHENYLETHYL ALCOHOL AGAR [Used for the isolation of gram positive bacteria] CHEMICAL COMPOSITION S.NO. COMPOUND VOL. IN 1000 ML 1 Casein enzymic hydrolysal 15 gm 2 Soya peptone 5 gm 3 Sodium chloride 5 gm 4 Phenyl alcohol 2.50 gm 5 Agar 15 gm

17. ENRICHMENT MEDIA This media allow metabolically fastidious microorganism to grow because the addition of specific growth factor. It is same as selective media , but enrichmnet media is liquid in consistency.

18. It is used to isolate SALMONELLA Species. COMPOSITION s.no . COMPOUND VOLUME IN 1000 ML 1 Casein enzymic hydrolysate 5 gm 2 lactose 4 gm 3 Sodium phosphate 10 gm 4 Sodium hydrogen selenit 4 gm SELENITE F BROTH

19. LACTOSE BROTH [ FOR detection of COLIFORMS and SALMONELLA. COMPOSITION S.NO. COMPUND VOL. IN 1000 ML 1 Peptone 5 gm 2 Beef extract 3 gm 3 lactose 5 g,

20. STORAGE OF CULTURE MEDIA Prepared media in individual screw capped bottles can be stored for weeks at room temperature .