• We are sorry, but NCBI web applications do not support your browser and may not function properly. More information
Logo of applmicroPermissionsJournals.ASM.orgAEM ArticleJournal InfoAuthorsReviewers
Appl Microbiol. Jun 1975; 29(6): 807–813.
PMCID: PMC187084

Improved Medium for Lactic Streptococci and Their Bacteriophages

Abstract

Incorporation of 1.9% β-disodium glycerophosphate (GP) into a complex medium resulted in improved growth by lactic streptococci at 30 C. The medium, called M17, contained: Phytone peptone, 5.0 g; polypeptone, 5.0 g; yeast extract, 2.5 g; beef extract, 5.0 g; lactose, 5.0 g; ascorbic acid, 0.5 g; GP, 19.0 g; 1.0 M MgSO4·7H2O, 1.0 ml; and glass-distilled water, 1,000 ml. Based on absorbance readings and total counts, all strains of Streptococcus cremoris, S. diacetilactis, and S. lactis grew better in M17 medium than in a similar medium lacking GP or in lactic broth. Enhanced growth was probably due to the increased buffering capacity of the medium, since pH values below 5.70 were not reached after 24 h of growth at 30 C by S. lactis or S. cremoris strains. The medium also proved useful for isolation of bacterial mutants lacking the ability to ferment lactose; such mutants formed minute colonies on M17 agar plates, whereas wild-type cells formed colonies 3 to 4 mm in diameter. Incorporation of sterile GP into skim milk at 1.9% final concentration resulted in enhanced acid-producing activity by lactic streptococci when cells were inoculated from GP milk into skim milk not containing GP. M17 medium also proved superior to other media in demonstrating and distinguishing between lactic streptococcal bacteriophages. Plaques larger than 6 mm in diameter developed with some phage-host combinations, and turbid plaques, indicative of lysogeny, were also easily demonstrated for some systems.

Full text

Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (1.2M), or click on a page image below to browse page by page. Links to PubMed are also available for Selected References.

Images in this article

Click on the image to see a larger version.

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Bertani LE, Bertani G. Preparation and characterization of temperate, non-inducible bacteriophage P2 (host: Escherichia coli). J Gen Virol. 1970 Feb;6(2):201–212. [PubMed]
  • Bertani G, Choe BK, Lindahl G. Calcium sensitive and other mutants of bacteriophage P2. J Gen Virol. 1969 Jul;5(1):97–104. [PubMed]
  • CITTI JE, SANDINE WE, ELLIKER PR. COMPARISON OF SLOW AND FAST ACID-PRODUCING STREPTOCOCCUS LACTIS. J Dairy Sci. 1965 Jan;48:14–18. [PubMed]
  • Douglas J. A critical review of the use of glycerophosphates in microbiological media. Lab Pract. 1971 May;20(5):414–passim. [PubMed]
  • Douglas J, Qanber-Agha A, Phillips V. Medium for the propagation and assay of lactic and other phages. Lab Pract. 1974 Jan;23(1):3–4. [PubMed]
  • Kozak W, Rajchert-Trzpil M, Zajdel J, Dobrzański WT. Lysogeny in lactic streptococci producing and not producing nisin. Appl Microbiol. 1973 Feb;25(2):305–308. [PMC free article] [PubMed]
  • Lowrie RJ. Lysogenic strains of group N lactic streptococci. Appl Microbiol. 1974 Jan;27(1):210–217. [PMC free article] [PubMed]
  • McKay LL, Baldwin KA, Zottola EA. Loss of lactose metabolism in lactic streptococci. Appl Microbiol. 1972 Jun;23(6):1090–1096. [PMC free article] [PubMed]
  • Molskness TA, Sandine WE, Brown LR. Characterization of lac+ transductants of Streptococcus lactis. Appl Microbiol. 1974 Nov;28(5):753–758. [PMC free article] [PubMed]
  • Nyiendo J, Seidler RJ, Sandine WE, Elliker PR. Preparation and storage of high-titer lactic streptococcus bacteriophages. Appl Microbiol. 1974 Jan;27(1):72–77. [PMC free article] [PubMed]
  • Pearce LE, Skipper NA, Jarvis BD. Proteinase activity in slow lactic acid-producing variants of Streptococcus lactis. Appl Microbiol. 1974 May;27(5):933–937. [PMC free article] [PubMed]
  • Thomas TD, Jarvis BD, Skipper NA. Localization of proteinase(s) near the cell surface of Streptococcus lactis. J Bacteriol. 1974 May;118(2):329–333. [PMC free article] [PubMed]

Articles from Applied Microbiology are provided here courtesy of American Society for Microbiology (ASM)

Formats:

Related citations in PubMed

See reviews...See all...

Cited by other articles in PMC

See all...

Links

Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...