Lactobacillus_Mrs_Agar_TD

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LACTOBACILLUS MRS AGAR (MRS AGAR) (VEG.) is used for isolation and cultivation of Lactobacilli species. Medium contains Veg. PP peptone, Veg. BE extract, and Yeast extract are the carbon, nitrogen and vitamin sources used to satisfy general growth requirements in Lactobacilli MRS agar.

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TITAN MEDIA For isolation and cultivation of Lactobacillus species Composition Ingredients Gms/Ltr. Dextrose 20.00 Agar 12.00 Veg. PP peptone 10.00 Veg. BE extract 10.00 Yeast extract 5.00 Sodium acetate 5.00 Ammonium citrate 2.00 Disodium phosphate 2.00 Tween 80 1.00 Magnesium sulphate 0.10 Manganese sulphate 0.05 Dehydrated powder hygroscopic in nature store in a dry place in tightly-sealed containers below 25°C and protect from direct Sunlight. Instructions for Use Dissolve 67.15gms in 1000ml of distilled water. Gently heat to boiling with gentle swirling and dissolve the medium completely. Sterilize by autoclaving at 15 psi 121°C for 15 minutes. Cool the medium at 45 – 50 0 C prior to dispense into sterile Petri plates. Appearance: Medium to dark amber colour clear to slightly opalescent gel forms in petri plates pH at 25°C: 6.5 ± 0.2 Principle LACTOBACILLUS MRS AGAR MRS AGAR VEG. is used for isolation and cultivation of Lactobacilli species. Medium contains Veg. PP peptone Veg. BE extract and Yeast extract are the carbon nitrogen and vitamin sources used to satisfy general growth requirements in Lactobacilli MRS agar. Dextrose is the fermentable carbohydrate and energy source. Tween 80 is a surfactant which supplies fatty acids required for facilitating metabolism uptake of nutrients by Lactobacilli. Sodium acetate and Ammonium citrate acts as a selective inhibitory agent for e.g. Streptococci moulds and many other microorganisms. Magnesium sulphate and Manganese sulphate provide cations used in metabolism. Disodium phosphate provides good buffering action in the media. Lactobacilli appear as large white colonies embedded in or on Lactobacilli MRS Agar. Growth may be subcultured onto the appropriate media for use in additional procedures. Lactobacilli are microaerophillic and generally require layer plates for aerobic cultivation on solid media. Organisms other than lactobacilli may grow in these media. Isolates of Lactobacilli confirmation must be done by biochemical testing. LACTOBACILLUS MRS AGAR MRS AGAR VEG. TMV 146

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TITAN MEDIA Interpretation Culture characteristics observed after inoculating 10 3 CFU/ml for incubation period of 3 days at 35°C and for 5 days at 30 0 C in an aerobic atmosphere supplemented with CO 2. Microorganism ATCC Inoculum CFU Observation CFU Standard recovery Recovery on test media Lactobacillus casei 9595 85 Good 50 50 Lactobacillus fermentum 9338 86 Good 50 50 Lactobacillus leichmannii 7830 89 Good 50 50 Escherichia coli 25922 80 Inhibited 0 0 References 1. deMan J. Rogosa M. and Sharpe M. J. Appl. Bacteriol. 23:130. 1960. 2. Marshall R.T. Ed. Standard Methods for the Examination of Dairy Products 16th ed. APHA 3. Washington D.C. 1992. 4. Downes F. P. and Ito K. Eds. Compendium of Methods. For the Microbiological Examination of Foods 4th Ed. APHA Washington D.C. 2001. 5. Sabine and Vaselekos Nature 206:960. 1965. 6. MacFaddin J. Media for Isolation-Cultivation-Identification-Maintenance of Medical Bacteria Vol.1 Williams and Wilkins Baltimore. 1985.

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