Thermophilic bacteria / by Allan Macfadyen, M.D. and Frank R. Blaxall, M.D.

  • Macfayden, Allan, 1860-1907
Date:
[1894?]
Catalogue details

Licence: Public Domain Mark

Credit: Thermophilic bacteria / by Allan Macfadyen, M.D. and Frank R. Blaxall, M.D. Source: Wellcome Collection.

    3/18
    By Allan Macfadyen, M.D., Professor of Bacteriology, College of State Medicine; and Frank R. Blaxall, M.D. From the British Institute of Preventive Medicine. The range of temperature at which it is possible for bacteria to grow is very great. Forster,1 2 for example, proved that certain bacteria were capable of growth and multiplication at zero. These organisms were found by him in water, milk, soil, and street mud. When cultivated at this low temperature they still produced pigment, gas, light, etc. The apparently unfavourable external conditions did not overcome the vitality of the cells or interfere with the exercise of their specific properties. For a large number of bacteria, 15°-20° C. is the optimum tempera¬ ture, whilst for pathogenic bacteria the optimum temperature is blood heat. At temperatures above 40° C. relatively few micro-organisms grow, and at 50° C. most nonspore-bearing organisms quickly die. But there is undoubtedly a group of micro-organisms which can grow at temperatures above 50° C., and for which such high temperatures furnish the best conditions for their growth and development. Miquel’s Bacillus therniophilus2 is perhaps the most familiar example. It was found by him in air, rain water, river water, and in the alimentary canal of man and animals. It grows best at a temperature of from 65°-70° C. Van Tieghem 3 also describes a micrococcus which grew at 70° C., and Certes and Garrigon4 found, in the waters of Luchon, bacilli that could be cultivated at 64° C. The temperatures at which it is possible for bacteria to grow range therefore from zero to 70° C. Globig,5 on inoculating sterile milk and beef-broth with garden earth, obtained a growth of bacteria at 58° C. They were exclusively bacilli, and in many cases they produced spores after 24 hours’ incubation at this temperature, potatoes being used as a culture soil. Globig obtained 30 bacteria, which grew at 58° C. At 68° C. only a few continued to grow. One bacillus grew at 68° C. and also at 15°-20° C. This was the greatest range of 1 Oentralbl. f. Balcteriol. u. Parasitenlc. bd. xii. 2 Ann. de Micrographie, No. 1, 1888. 3 Bull. Soc. Bot. de France, tome xxviii. 4 Compt. rend. Acad, sc., Paris, tome iii.