English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The efficiency of plating of phages derived by ultraviolet induction of, or by lytic growth on, certain strains of Streptococcus cremoris was found to vary by as much as 10 depending on the lactose concentration of the medium in which the indicator bacteria were grown and the length of time the stationary-phase indicator cultures were aged. This effect was noted only when the culture was used as an indicator for phages that had previously grown on an apparently unrelated strain of bacteria. Conditions of culturing and aging had no detectable effect upon the ability of a strain to serve as an indicator for phage that had previously been cultured on the same strain. These observations suggest the presence of some kind of physiologically labile restriction system in strains of S. cremoris. The implications of this finding for increasing the sensitivity of the host range test in determining phage susceptibility, whether from induced lysates, whey, or lytic phage stocks, are discussed. It is recommended that, for all such testing, the concentration of lactose in buffered media be increased to such levels as required to obtain a final pH similar to that of a freshly coagulated milk culture, namely, below pH 5.0.

Effect of Lactose Concentration on the Efficiency of Plating of Bacteriophages on Streptococcus cremoris