To learn more about the role β-galactosidase plays in rate of
acid production in milk by lactic acid bacteria, several lactobacilli
were examined for this enzyme. Cells from different species were
grown in lactose broth to induce β-galactosidase activity. The specific
activities of whole, solvent treated cells, and of cell-free...
Streptococcus lactis C2F and Streptococcus cremoris 459 grew
to a maximum population of 1 to 2 x 10⁹ colony forming units (cfu)/ml with a generation time of 96 min in 11% nonfat dry milk (NFDM)
under static conditions at 22° C.
Streptococcus diacetilactis 18-16
grew to a maximum population of...
Lactic streptococcal agglutinins are known to promote settling of starter bacteria in milk, resulting in spongy, mealy, shattered curd and sludge formation defects in cottage cheese. These agglutinins are natural antibodies secreted by lactating cows in mature milk in response to infections (mastitis) and in colostrum milk as protective antibodies...
Mutants of Streptococcus lactis 7962 with various combinations of plasmid molecular masses were screened for nisin production. Nisin was produced by both wild type and mutants that contained a 17.5 Md plasmid, which was usually obscured by the chromosomal fragments. No nisin was produced by plasmid-free mutants. Sucrose fermentation and...