Identification of Zoogloea species and the relationship to zoogloeal matrix and floc formation

Three floc-forming, gram-negative, polarly flagellated rods were isolated and characterized. Our isolates were compared to four similar floc-forming organisms previously isolated in another laboratory and classified as two species of Zoogloea, one of Pseudomonas, and as one unidentified gram-negative rod. Possession of zoogloeal matrix or flocculent growth habit was examined in relation to growth and biochemical patterns of the bacteria. A possible relationship of Zoogloea to other gelatinous matrix-producing bacteria is also discussed.