Environmental factor differences related to the growth of three species of Monoblepharella

Abstract

Axenic cultures were made of three species of Monoblepharella. These were subsequently used in a physiological and nutritional investigation of the organisms. Growth of Monoblepharella laruei Springer (1945), Monoblepharella taylori Sparrow (1940) and Monoblepharella elongata Springer (1945) during the experiments was determined in synthetic media by means of dry weight measurements. All species were found to have optimum growth at 28 C with ranges extending somewhat higher than most water molds, The pH ranges from 4.5 to greater than 8 were similar to most aquatic fungi. Nutritional requirements of the organisms for carbohydrates, inorganic and organic nitrogen and vitamins were determined. With the exception of xylol and sorbitol all of the carbohydrates studied were metabolized by M. laruei. In addition to these M. taylori and M. elongata could not utilize lactose. Only M. taylori was incapable of using mannose. Deficiencies in the ability to synthesize the vitamins, nicotinic acid biotin and thiamin were indicated in all species with one exception. M. elongata does not grow with nicotinic acid added. None of the organisms was able to use the salts NH₄NO₃, or NH₄Cl. However all of the organisms produced a slight growth using NaNO₃. All of the organisms could metabolize the single amino acids, DL-alanine and DL-methionine, or combinations of the amino acids in the form of peptone. Growth in media containing all of these nutrients is similar to that found in most of the more highly evolved aquatic Chytridiomycetes.