title: Effect of aponin, a substance from a green alga Nannochloris species, on the spore germination of two fungi.
abstract: Fungistasis which occurs in soil has also been reported to exist in seawater. Nannochloris sp. (Chlorophyta) found along the west coast of Florida, has been shown to elaborate a compound which is cytolytic towards Ptychodiscus brevis, the Florida red tide organism. Aponin, a chloroform extract containing the cytolytic compound or compounds, was tested on the spore germination of two fungi, Dendryphiella salina, a facultative marine organism and Curvularia sp. a terrestrial one. Aponin was stimulatory towards D. salina at all concentrations tested, while Curvularia sp. was stimulated at the highest concentration used but inhibited at the lower concentrations. The culture age of the two fungi did not alter the relative sensitivity of both fungi towards aponin but the germination percentage of Curvularia sp. was affected by the culture age. An aqueous extract of Nannochloris sp. was also tested on the two fungi and was shown to be inhibitory to both. The results seem to indicate that more than one compound from Nannochloris sp. is capable of affecting spore germination indicating that this alga might be playing a role in the reported fungistasis in seawater. Gulf seawater was tested and found to have little if any fungistatic activity.
mesh_terms: D000460:Chlorophyta / Q000032:analysis*; D003603:Cytotoxins / Q000494:pharmacology*; D005658:Fungi / Q000187:drug effects*; D010936:Plant Extracts / Q000494:pharmacology*; D012623:Seawater; D013172:Spores, Fungal / Q000502:physiology
chemical_list: D003603:Cytotoxins; D010936:Plant Extracts; C014340:aponin