Staphylococci, particularly the aureus and albus types, have been isolated from a great variety of sources since they were first grown in pure culture by Rosenbach.1 Many times several varieties have been isolated from the same source, thus causing much confusion as to their functional activities. In a study of their physiologic and biologic activities we have been considerably impressed with the various changes which they produce in milk, and consequently have made detailed studies relating to them. Thorough investigation of bacteria includes specific studies of their morphologic, metabolic, and biologic variations, and no classification which omits one of these important factors is complete. Buchner2 proved that fermentation processes, such as alcoholic, lactic, and acetic fermentations are processes not caused directly by bacteria themselves but by the enzymes they produce. Emil Fischer3 claimed that there must be a similarity between the structure of enzymes and the structure which they decompose, and he compares their resemblance in structure to that necessary between a lock and a key in order that the latter may pass the lock. Pasteur4 believed that fermentation corresponds to the respiration processes of animals, except that it is respiration without oxygen. Harden5 believed that certain organisms bring about curdling of milk by changing the sugar content to lactic acid as CeH^Oc ?* 2CH3CH (OH)COOH. He thought that different strains of organisms are distinguished by a proportion of different by-products. Savage,6 working with B. coli, found that they converted soluble caseinogen to an insoluble casein but played no part in the initial curdling of milk. He ascribed this change to the action of an enzyme which these organisms produced. Kamm7 has recently shown that phosphates are the essential agent for favoring gas production by bacteria, while a scant supply of minerals causes bacteria to produce lactic acid. One must therefore assume that two chemical processes are carried on as
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Jan 1, 1963
St Kryñski + 3
Open Access