BACTERIAL FLORA OF CHEDDAR CHEESE.

Lyttelton Times, Volume CXXI, Issue 15331, 14 June 1910, Page 10

BACTERIAL FLORA OF CHEDDAR CHEESE.

(By K. A. HARDING and M. J. PRUOHA, in the "New York State Station.'') The results are reported of a quantitative and qualitative study of the flora in nine normal Cheddar cheeses during the ripening period. More than 3CO pure cultures were isolated and finally reduced to thirty-three, groups accortl ing to tho classification of the Society of American Bacteriologists. Ten. ci these groups disappeared from the cheeso at once; representatives of nine other groups were found in but single cheeses, although each group persisted for somo time in the cheese when found; the remaining fourteen group. are tho most important members Oi the cheese flora. "The Bacterium lactis acidi of Lcichmann, which include:, four of these fourteen groups, is the only species which was always found. and it practically always included ovei 99 per cent cf tho total germ content. The initial flora of milk, of course, varies widely, depending upon its environment. When, this milk is mads into cheese tho accompanying change: in temperature, moisture and acidity induce a rapid shift in this flora, and some of tho forms which grow best in milk are lost before they can be observed, for they will not grow on any culture media now in. use. As the whey is expelled from the coagulated mass it does not contain its volumetric proportion of the germs previously found in the milk. .No data are given on the freshly coagulated curd. Tho results" obtained from a study of individual cheeses during ripening are presented in tabular form. In different cheese tho rate of increase, the maximum germ content, and the age at which it is obtained, as well as the rate of decline after this point, varied greatly. The causa of these variations are onlv partly understood. The lowest recorded maximum, 27.000.000, and the highest, 178.000.000 per gramme, are in the two ci'c-oses having a very qualitative flora and ripening in a similar manlier. The rata of ripening in these two cheesss was slightly different, the one with the highest maximum germ content ripering more slowly. The average germ content of al! the choj&e examined was 10.000,000 '>er gramme at the end of fivo hours, 30.000,000 at the end of one dray, 40,700,000 at the end of ten days, 10.200.000 at the end of fifty days, 2.G25.000 at the end of 100 days, and 500,000 at the end of 150 days._ The type Bacterium lactis acidi makes up 99 per cent or mere of the flora of normal Cheddar cheese in prao> tically all cases. The representatives of this type differ in their relation to air and in their ability to attack saccharose, so Dliat they are found under four different group numbers. Streptococcus laetieus, which includes two different . group numbers, is occasionally found in much smaller numbers. These groups apparently a<j2'ee with the corresponding groups cf Bacterium lactis acidi in everything except morphology. The position taken by Conn, that there is a distinct morphological baeis for tho separation of the cocci from tho rod forms, appear;; to be well taken. Both the morphology and the physiology of these groups is easily influenced by their environment?, and it is especially important that the en'turo'i he broujrht to a vifj'orc-us condition, before bping subjected to detailed study. COLDS. How often we hear tho renr.rlr, "It is only a cold." and a Few clays later the man is on his back with pneumonia. This is such a common occurrence that a cold, however slight, should not be neglected. Chamberlain's Cough Remedy has gained its great popularity s,nd imiiier.ce sales by its prompt euros of this most common ailment. It always cures, and is pleasant to take. It counteracts any tendency of a cold to result in pneumonia. 3 :