Comparison of bacterial and phytoplankton populations under natural and laboratory conditions

Bacteria and blue-green algae were isolated from Oneida Lake, N.Y., and other sources. The blue-green algae Anabaena flos-aquae, Anabaena spiroides, Gloeotrichia echinulata, and Microcystis aeruginosa were grown under laboratory conditions and were separated into unialgal cultures. The bacterial population living in association with the unialgal blue-green algae differed significantly from the bacterial flora of Oneida Lake. Bacillus, Pseudomonas, Aeromonas, and Zoogloea were the most frequently occurring genera of bacteria from the lake, whereas Flavobacterium, Achromobacter, and Pseudomonas were the most common bacteria isolated from laboratory blue-green cultures. Nutritional and physiological characteristics of bacteria isolated in the laboratory were more uniform than those isolated from the lake.