Bacto Casitone, Trypticase Peptone, Bacto Tryptone and BiTek Tryptone are used in preparing microbiological culture media.
Ingredients, where noted, meet United States Pharmacopeia (USP) performance specifications.
The manufacturing process for an enzymatic digest of casein is not as destructive as an acid hydrolysis. Thus, the casein is not broken down as completely into its constituent components. In many cases this makes for a more nutritious hydrolysate, especially for those organisms that prefer peptides to amino acids.
Bacto Casitone can be used as a component in microbiological culture media or in fermentation applications. A recent publication has also reported that the stability of lyophilized influenza virus vaccine was augmented by the addition of 2% Casitone.1
Bacto Casitone, Trypticase Peptone, Bacto Tryptone and BiTek Tryptone are pancreatic digests of casein. Casein is the main milk protein and a rich source of amino acid nitrogen.
Identity Specifications
Casitone
Dehydrated Appearance: Tan, free-flowing, granules.
Solution: 1.0%, 2.0% and 10.0 % solutions, soluble in
purified water. 1.0% solution is light amber,
clear. 2.0% solution is light to medium amber,
clear, may have a slight precipitate. 10.0%
solution is medium to dark amber, clear to very
slightly opalescent, may have a precipitate.
Reaction of 1.0%
Solution at 25°C: pH 6.8-7.4
Cultural Response
Biochemical Reactions
Casitone
Prepare a sterile solution as directed below. Adjust final pH to 7.2-7.4. Inoculate and incubate at 35 ± 2°C for 18-48 hours.
TEST | TEST SOLUTION | ORGANISM | ATCC™ | INOCULUM CFU |
RESULT |
Fermentable Carbohydrates | 2% | Escherichia coli | 25922 | ~107 | Negative |
Indole Production | 0.1% | Escherichia coli | 29552 | 0.1 mL, undiluted | Positive |
Acetylmethylcarbinol Production | 0.1% with 0.5% dextrose | Enterobacter aerogenes | 13048 | 0.1 mL, undiluted | Positive |
Hydrogen Sulfide Production | 1% | Salmonella enterica subsp. enterica serotype Typhimurium |
14028 | 0.1 mL, undiluted | Positive |
Growth Response
Casitone
Prepare a sterile solution with 2.0% Bacto Casitone, Bacto Tryptone or BiTek Tryptone, 0.5% sodium chloride and 1.5% agar. Adjust final pH to 7.2-7.4. Inoculate and incubate plates at 35 ± 2°C for 18-48 hours.
ORGANISM | ATCC™ | INOCULUM CFU |
RECOVERY |
Escherichia coli | 25922 | 30-300 | Good |
Staphylococcus aureus | 25923 | 30-300 | Good |
Refer to Product Tables in the Reference Guide section of this manual.
Refer to the final concentration of Bacto Casitone, Trypticase Peptone, Bacto Tryptone and BiTek Tryptone in the formula of the medium being prepared. Add appropriate product as required.
See appropriate references for specific procedures using Bacto Casitone, Trypticase Peptone, Bacto Tryptone and BiTek Tryptone.
Refer to appropriate references and procedures for results.
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