Interrelation of pH, Temperature, and Growth in the Induction of Pleomorphism in Trichophyton Mentagrophytes

Effect of Carbon and Nitrogen Nutrition on Pleomorphism in Trichophyton Mentagrophytes

“…Culture media-The medium contained (g or nil/liter) MgS0 4·7H20, 0.5; KH2P04,1.5;K2HPO t ,0.15;0.5;thiamin,0.01;Difco Neopeptone,2;glucose,20;agar,where required,15. In certain experiments other sources of nitrogen were substituted for Neopeptone, e.g., vitamin-free, acid-hydrolyzed casein; 19 L-amino acids, each at the concentration found in hydrolyzed casein (Klein, 1963); glutamic acid; asparagine; or ammonium chloride. In certain experiments other carbohydrates or carbon-containing compounds were substituted for glucose.…”

“…Where nitrogen sources varied, the carbon source was 2% glucose; where carbon sources [Vol. 52 patches were also made from certain experiments in order to determine whether changes in media affected the initial mutational event(s); that is, were those genetic attributes characteristic of the pleomorphic mutant (fluffiness, lack of pigmentation, methionine insensitivity) (Klein, 1963) differentially affected? RESULTS AND DISCUSSION-Effect of glucose on pleomorphism and dry weight yield of strain M12-J,.…”

“…-Glucose was employed as the standard source of carbohydrate in previous work of the author (Klein, 1963;1964a, 1964b and by all other investigators who have studied pleomorphism. In order to use glucose as a basis for comparison, the optimum concentration was determined both for dry weight yield of liquid cultures and development of pleomorphic patches on agar cultures of granular strain M12-4.…”

“…Conditions of growth-Cultures used as a source of inoculum were grown in petri dishes or test tubes on 0.2% Neopeptone-2% glucose agar medium at 26 C. Inocula for experimental agar plates (30 ml/plate) were disks of agar cut from the advancing edge of mycelial growth with a 4-mmdiam cork borer. These cultures were incubated at 36 C for 21 days (Klein, 1964a), at which time a final count was made of pleomorphic patches; 2 or 3 plates were used per variable and each experiment was repeated at least once.…”

“…I solation from pleomorphic patches-Visual scoring of pleomorphic mutant patches is a reliable procedure (Klein, 1964a) and was used in the present study. Isolations from visually scored • Concentration of Neopeptone was 0.2%.…”