The ferment-action of bacteria / T. Lauder Brunton, M.D., F.R.S., and A. MacFadyen, M.D., B.Sc.

  • Brunton, T. Lauder (Thomas Lauder), 1844-1916
Date:
[1899?]
Catalogue details

Licence: Public Domain Mark

Credit: The ferment-action of bacteria / T. Lauder Brunton, M.D., F.R.S., and A. MacFadyen, M.D., B.Sc. Source: Wellcome Collection.

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    id does so more surely and quickly than the enzyme formed in slatine itself. 2. The liquefaction is produced by a soluble ferment, since its ;tion can be demonstrated apart from the microbes which pro¬ ice it. III. Instead of using heat sterilisation some experiments were made ith menthol and thymol. It was found that when these substances were added in amounts Lfficient to prevent the growth of the bacteria—the ferment action as likewise inhibited. IV. The presence of a soluble ferment being demonstrated, can we olate it P (1.) From gelatine. (2.) From meat broth. (1.) From Gelatine Cultures. Flasks containing 250 c.c. of 10 per cent, gelatine were inoculated ith the five microbes. They were left in the incubator at 47° C., rutrefactive micrococcus, 32° C.), till liquefaction was complete, he liquefied gelatine was treated with absolute alcohol and filtered, he precipitate was extracted with glycerine, and finally repre- pitated with alcohol. The precipitate, after drying in a sterilised isk, was taken up in a small quantity of sterile distilled water, and lowed to stand over night. About 5 c.c. were then added to 10 per 3nt. gelatine, and incubated at 37° C. Results.—Negative. No liquefaction was produced. (2.) Meat Broth Cultures. In each case 250 c.c. were treated in a similar manner—with cohol and glycerine, and the precipitate and sterile distilled water Ided to 10 per cent, gelatine. Results :— Koch’s spirillum Finkler’s spirillum Putrefactive micrococcus Scurf bacillus Welford bacillus Control plates. Concluding that the prolonged method of extraction had weakened b 2 ^.No liquefaction. 4 In a few tubes the gelatine was / viscid. The rest resolidified. No colonies.