EFFECTS OF TEMPERATURE AND OXYGEN CONCENTRATION ON GEOSMIN PRODUCTION BY STREPTOMYCES-TENDAE AND PENICILLIUM-EXPANSUM

Streptomyces tendae cultures incubated at 30 and 45 degrees C for 48 h produced more biomass and more of the earthy odorant geosmin (1 alpha,10 beta-dimethyl-9 alpha-decalol) than those incubated at 10 and 20 degrees C, indicating an association between biomass production and geosmin accumulation in these bacterial cultures. However, the fungus Penicillium expansum incubated at 20 degrees C produced ca. 85% more biomass than those incubated at 40 degrees C, and cells incubated at 40 degrees C contained an order of magnitude higher concentration of geosmin than those incubated at 20 degrees C. Exposure to 10% O-2 and 90% N-2 increased the accumulation of geosmin by P. expansum cells compared to ambient atmosphere-incubated controls. However, O-2 enrichment (30% O-2, 70% N-2) increased the geosmin accumulation by cultures of S. tendae compared to ambient atmosphere-incubated controls.