| Abstract: | Axenic and bacteria-containing assays with the coccal green alga, Scenedesmus subspicatus, were compared with respect to the growth inhibition and promotion, respectively, of one fulvic acid source. In the presence of Fuhrberg fulvic acids, a groundwater fulvic acid from lignite leachate, algal growth was promoted, if bacteria were present. This effect occurred although fulvic acids clearly quenched the available light. We presume that the fulvic acids were utilized by microbes, which, in turn, may have produced and released organic substances, which appeared to be beneficial to the algae. |
