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91015 Tributyrin Agar

For the detection and enumeration of lipolytic microorganisms in food and other material (staphylococci, pseudomonads, clostridiae and marine flavobacteria). Composition: Ingredients Special peptone Yeast extract Agar Final pH 7.5 +/- 0.2 at 37° C Grams/Litre 5.0 3.0 12.0

Store prepared media below 8° protected from direct light. Store dehydrated powder, in a dry place, in tightly-sealed C, containers at 2-25°C. Directions: Dissolve 20 g in 1 litre distilled water. Sterilize by autoclaving at 121° for 15 minutes. Let cool to 80° and add 10g C C neutral Tributyrin (Fluka No. 91010). Mix thoroughly to emulsify the Tributyrin completely. Pour plates in order to maintain uniform turbidity. If the emulsion separates, the effectiveness of the culture medium is affected. Principle and Interpretation: Tributyrin Agar was originally formulated by Anderson [1] for the detection and enumeration of lipolytic microorgannisms such as Staphylococci [2], Clostridia [3], marine Flavobacteria and Pseudomonas [4] and moulds in foodstuffs and other materials. It has beeen reported that other glycerides such as Triolein and Trilinolein may be used instead of Tributyrin [5]. According to Rapp [6], better emulsification of Tributyrin can be achieved if 4 ml Polyoxyethylene-(20)-hydrated castor oil is added to 1 litre of the culture medium. Special peptone and yeast extract provide nutrients e.g. organic nitrogen, carbon compounds and other growth factors like vitamines to the organisms. Tributyrin degradation by the microorganisms is indicated by clear zones surrounding the lipolytic colonies in the otherwise turbid culture medium. Cultural characteristics observed after 24-48 hours at 35-38°C, in an appropriate atmosphere: Organism (ATCC) Bacillus subtilis (6633) Escherichia coli (25922) Staphylococcus aureus (25923) Clostridium sporongens (11437) Clostridium perfringens (12924) Salmonella typhimurium (14028) Pseudomonas aeruginosa (27853) Penicillium commune (10428) Key (Lipase activity): Growth +++ +++ +++ +++ +++ +++ +++ + Lipase activity + + + + +

+ = clear zone around colony - = absence of zone

References: 1. J.A. Anderson, Ber. Iird. Int. Mikrobiol. Kongress, 3, 726-728 (1939) 2. A.G. Imnes, J. Appl. Bact., 19, 39-45 (1956) 3. A.T. Willis, J. Path. Bact., 80, 379-390 (1960) 4. P.R. Hayes, J. Gen. Microbiol., 30, 1-19 (1963) 5. G.M. El Sadek, T. Richards, J. Appl. Bact., 20, 137 (1959) 6. M. Rapp, Milchwirtsch., 33, 493-496 (1978)

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