A course of elementary practical bacteriology : including bacteriological analysis and chemistry / by A. A. Kanthack ... J. H. Drysdale.

  • Kanthack, A. A. (Alfredo Antunes), 1863-1898.
Date:
1895
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Licence: Public Domain Mark

Credit: A course of elementary practical bacteriology : including bacteriological analysis and chemistry / by A. A. Kanthack ... J. H. Drysdale. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

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    Conclusions: Invertine is an enzyme, and therefore not destroyed by chloroform. The alcohol-producing ferment is a living ferment, and as such is destroyed by chloroform. C. Action of Moist Heat on Enzymes. (1) Prepare a suspension of yeast in lukewarm sterile water. (2) Shake up a little of it with chloroform as above, and allow the chloroform to settle. (3) Separate the supernatant liquid, and pour a little of it into two test-tubes. (4) Heat one of them up to boiling point, leaving the other for control. (5) Add some of the boiled suspension to two tubes con- taining a dilute solution of cane sugar, and keep the tubes at 38-5° C. Test one tube with Fehling's solution after four to six hours : no reduction of copper and no alcohol. Test the other tube with Fehling's solution after twenty-four hours : no reduction of copper and no alcohol. (6) Add some of the suspension in the control tube to two tubes containing a dilute solution of cane sugar, and keep the tubes at 38-5° C. Test one tube with Fehling's solution after four to six hours : marked reduction of copper.