THE INFLUENCE OF GROWTH-CONDITIONS ON ODOR-COMPOUND PRODUCTION BY 2 CHRYSOPHYTES AND 2 CYANOBACTERIA

The influence of several environmental factors (e.g., light intensity, temperature, nitrogen, and phosphorus) on population density and odor -compound production of two chrysophytes, Synura petersenii and Dinobr yon cylindricum; and two cyanobacteria, Anabnena laxa and Phormidium c alcicola was investigated. The odors associated with each alga were ev aluated by flavor profile analysis (FPA) at several intervals during t heir initial culturing in defined media Algal cell and media extracts were analyzed individually by capillary gas chromatography-mass spectr ometry (GC-MS). Both cyanobacteria produced geosmin (''earthy'' and '' corn'' odors); however, the P. calcicola also produced relatively larg e amounts of MIB (''musty-earthy'' odors). Both chrysophyte cultures c ontained 2t,4c,7c-decatrienal (''fishy'' odor); and in addition, 2t,6c -nonadienal (''cucumber'' odor) was isolated from the S. petersenii. Y oung cultures of Anabaena (e.g., <20 days) retained most of the geosmi n produced. Throughout its population growth, more than 80 percent of the MIB and geosmin produced by P. calcicola was detected in the media rather than in the cells. Synura petersenii produced more 2t,4c,7c-de catrienal than 2t,6c-nonadienal and retained nearly 90 percent of both compounds throughout the algal population growth. Dinobryon cylindric um produced 2t,4c,7c-decatrienal, and, like the S. petersenii, retaine d most of the compound. Greater production of the compounds by the two chrysophytes was apparently associated with log-phase growth rather t han specific environmental conditions; extended log-phase growth (and prolonged production of compounds) was observed in the S. petersenii c ulture during the low-temperature treatment.