Tests of different media for the collection and identification of air-borne saprophytic fungi

Abstract

1. 1. The experimental results to date indicate that Mehrlich's medium with 75 Gm. of sodium chloride per 1000 c.c. of H 2O will give a significantly higher mold count per plate than the casein hydrolysate medium now employed in the air-borne mold survey. This medium supports the growth of a large number of the air-borne saprophytic fungi common to this region. 2. 2. There is evidence, however, that this medium is still not the best possible, since readings from the modified Smith-Humfeld salt agar show a mold count almost double the mold count obtained on Mehrlich's salt agar and almost triple the mold count from the casein hydrolysate salt medium. 3. 3. As a result, therefore, experiments with a further modified Smith-Humfeld salt medium, a purified malt salt agar, and reduced strengths of the casein hydrolysate medium are being continued. 4. 4. None of these media will disclose the presence of air-borne spores of obligate parasites or spores of some other fungi as mushrooms and wood-rotting fungi which may often be present in considerable numbers, but they may considerably increase the value of the surveys now being conducted.