Accelerated eutrophication is becoming a major problem in relation to surface waters. Controversy has arisen as to its causes in different types of natural systems. Investigations were made of the stimulatory and limiting effects of phosphate on the bacterium E. coli in synthetic media. Growth was measured in batch and continuous flow cultures using both turbidimetric and respirometric techniques. The results obtained were used to formulate a hypothesis concerning the stimulation of algae by inorganic carbon produced by bacteria and the role this relationship plays in the eutrophic processes that occur in natural systems where organic carbon is not limiting to bacterial populations. / Master of Science