M16 AGAR (MODIFIED ROGOSA AGAR

Streptococcus is a genus of spherical, gram-positive bacteria, and a member of the phylum Firmicutes. M16 Agar is a modification of Rogosa Sodium Lactate Agar recommended by APHA. This medium was developed to support growth of lactic streptococci used in cheddar cheese manufacturing in New Zealand. This medium can also be used as selective medium for the cultivation of oral and faecal lactobacilli. Since some lactobacilli do not grow on this medium if incubated aerobically, incubation in a CO2-enriched atmosphere is recommended. The large number of media proposed for lactic acid bacteria, particularly for streptococci and /or lactobacilli, is an indicative of the variability in growth features of different species, thereby the difficulties encountered in growing some strains of this group of organisms. While the lactic acid bacteria in general are tolerant to low pH, they can be very sensitive to other adverse conditions. Freezing and thawing prior to analysis may be detrimental to cell growth. Dilution process may also damage lactic acid bacteria in samples, thus it is best to use sterile 0.1% Peptone Water as the diluent.

for cultivation and enumeration of lactic streptococci used in manufacture of cheddar cheese