Another point in the cultivation of yeasts has been elucidated by a number of workers, chief among whom perhaps is Hansen, namely, methods of obtaining pure cultures.
This difference in the thermal death-point between bacilli and their spores enables the operator to obtain what are called "pure cultures" of a desired bacillus from its spores which may be present.
We have already mentioned the chief media which are used in the laboratory, and in an investigation many of these would be used, and thus pure cultures would be obtained.
The question of pure cultures alone is one of practical importance; the recognition of the causes of "diseases" of beer is another.
The difficulty of obtaining for experiment any one kind of bacteria by itself, unmixed with others (pure cultures), rendered advance almost impossible.
Two bacteriologists have experimented independently in fermenting tobacco leaves by the action of pure cultures of bacteria obtained from such sources.
Perhaps in this other fermentative industry, which is of such great commercial extent, the use of pure cultures of bacteria may in the future produce as great revolutions in methods as it has in the industry of the alcoholic fermentation.
Here also there is a possibility of an improvement in the process by the use of pure cultures of lactic organisms.
Climatic conditions in most dairy sections of America have been sufficiently unfavorable to make more or less continuous use of pure cultures desirable.
The alternative practice consists in the introduction of pure cultures of known strains of lactic bacteria into special milk to make the starter.
To further study the peculiarities of different germs, the separate colonies are transferred to other sterile tubes of culture material and thus pure cultures of the various germs are secured.
Artificial inoculation of cattle with tuberculous human sputum as well as pure cultures of this variety show that the human type is able to make but slight headway in cattle.
It is unfortunate that this same term is used in connection with the heating of cream as a preparatory step to the use of pure cultures in cream-ripening in butter-making.
Two of them were inoculated by intravaginal application of pure cultures, and two by intravaginal application of pieces of afterbirth from aborting cows.
Nowak induced abortion in pregnant guinea pigs with great regularity by subcutaneous, intraperitoneal, and intravenous injection of pure cultures of the abortion bacillus.
Abortion was also caused in sheep by intravaginal application and by intravenous injection of pure cultures.
These fetuses had been dead 9 months and 5 months respectively but the surrounding exudate still contained the abortion bacillus and pure cultures of it were obtained from each case.
Thus, the use of pure cultures in raw cream, and pasteurization together with the pure cultures, have a marked beneficial effect.
After the milk has been boiled and rapidly cooled, pure cultures of the lactic microbes are sown in it, in sufficient quantities to prevent the germination of spores already in the milk and not destroyed in the process of boiling.
There has been little success in producing it by pure cultures as would be necessary were it to be brought into general use.
Pure cultures of lactic acid bacteria coagulate the milk uniformly, but do not produce any subsequent change in the appearance of the culture, even after several months.
The above list will hopefully provide you with a few useful examples demonstrating the appropriate usage of "pure cultures" in a variety of sentences. We hope that you will now be able to make sentences using this group of words.
