. Fungous diseases of plants, with chapters on physiology, culture methods and technique . submerged ISOLATION AND PURE-CULTURE METHODS 19 spores, and consequently they may not germinate between thesuccessive sterilizations. On the other hand, if the medium isdeep in the vessel, and the exposed surface of the medium small,much less oxygen gains access, and the spores of anaerobic formspass more readily into the vegetative condition and are killed bythe successive sterilizations. Sterilization under pressure. A great time-saving convenienceIn sterilization is to be found in the use of the autoc
. Fungous diseases of plants, with chapters on physiology, culture methods and technique . submerged ISOLATION AND PURE-CULTURE METHODS 19 spores, and consequently they may not germinate between thesuccessive sterilizations. On the other hand, if the medium isdeep in the vessel, and the exposed surface of the medium small,much less oxygen gains access, and the spores of anaerobic formspass more readily into the vegetative condition and are killed bythe successive sterilizations. Sterilization under pressure. A great time-saving convenienceIn sterilization is to be found in the use of the autoclave, or steam. Fig. 5 b. Autoclave, Horizontal Type, connected with Steam Pipes(All steam apparatus under a hood) pressure sterilizer, two types of which are shown in Fig. 5, a and autoclave is not only more effective than the ordinar) steamsterilizer, but by using it the delay of discontinuous sterilization isavoided. In this apparatus the steam is confined, up to any pres-sure desired, instead of being allowed to escape, as in the ordinaiysteam sterilizer. A good steam pressure gauge on the autoclaveis requisite, and a thermometer is not only desirable, but also anadditional safeguard. The temperature ordinarily employed is 115^to 125° C, or about 10 to 20 lbs. pressure. A single incubation 20 CULTURE METHODS AND TECHNIQUE of from fifteen to twenty minutes at this temperature will usuallysterilize any medium. The period of incubation must of course bemeasured from the time the desired temperature is attained, and itmay require from ten to fifteen minutes, even with a strong burnersystem, in
Size: 1778px × 1405px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, bookpublisherbostonnewyorketcgi
