. The actinomycetes. Actinomycetales. nl^ sroLoov 133 90 • •'••• ••• ;••••" "••...••?? 70 - • • • •, • • • •. 50 / ^'-^'Oc'" / / 30 / / / \ / / \ / / 10 - / / ; DAYS. Figure 65. Effect of glucose on streptomycin production; key same as in Fig. 64. (Reproduced from: X. A. Krassilnikov, 1950, p. 206). grow only above a certain temperature, al- though they may remain alive, without multiplication, at much lower temperatures. When the temperature reaches a point which is specific for each organism, growth begins. The rates of reproduction and of the meta- bolic reactions increase ra
. The actinomycetes. Actinomycetales. nl^ sroLoov 133 90 • •'••• ••• ;••••" "••...••?? 70 - • • • •, • • • •. 50 / ^'-^'Oc'" / / 30 / / / \ / / \ / / 10 - / / ; DAYS. Figure 65. Effect of glucose on streptomycin production; key same as in Fig. 64. (Reproduced from: X. A. Krassilnikov, 1950, p. 206). grow only above a certain temperature, al- though they may remain alive, without multiplication, at much lower temperatures. When the temperature reaches a point which is specific for each organism, growth begins. The rates of reproduction and of the meta- bolic reactions increase rapidly with a fur- ther rise in temperature up to a certain point, which is again specific for each or- ganism. A still further rise in temperature leads to a drop in the rate of growth, until finally a point is reached at which growth stops. According to Haines (1932), the ordinary saprophytic actinomycetes found in cold stores and in soil fall into two groups: 1. Those organisms that have their optimum temperature for growth at 37° C, their range of growth extending from 40 to 5° C, with a lower limit at just about 0° C. 2. Those that have a less sharply defined optimum tem- perature, growth being rapid at 20 to 30° C; corresponding to a lower optimum tempera- ture is also a lower minimvmi temperature, growth being slow but good at 0° C, with a minimum between 0 and — 5° C. The con- clusion was reached that actinomycetes are probably of greater practical significance in modern trade practice in chilled meat, eggs, and possibly fruit than in well-frozen meat. The presence of active cultures is sufhcient, without actual grow'th, to cause a "musty" taste in the stored product. Three points are thus established in the temperature range for every organism: (a) a minimum or lower limit of growth; (b) a maximum or upper limit; and (c) an opti- mum at which growth is at its best. The optimmn temperature may not be a sha
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