A Microbial Biorealm page on the genus Zoogloea ramigera
Higher order taxa
Bacteria; Proteobacteria; Betaproteobacteria; Rhodocycales; Zoogloea
Description and significance
The generic name Zoogloea has its origin in the Greek language and translates as “living glue.” It is on this description of its unique characteristic that the organism obtained its name. Initially the only recognized species of the genus Zoogloea, Zoogloea ramigera is an aerobic, chemoorganotrophic, gram-negative, straight to slightly curved rod shaped, nonspore forming bacteria. Zoogloea ramigera occur free living in organically poluted fresh water and waste water at all stages of treatment.
Cell Structure and Metabloism
These bacteria are arranged in sharply demarcated columns or fingers which protrude from clusters and constitute the historically recognized growth form of Zoogloea ramigera. Cells are nonpigmented. Cells in older cultures may be encapsulated. Although aerobic, growth may occur anaerobicly in the presence of nitrate. The preferred temperature for growth is 28-37 degrees C. Zoogloea ramigera flourish in an environment with a pH of 7.0-7.5. This organism is Oxidase positive and weakly Catalase positive. The formation of flocs and films in liquid media at late stages of growth are distinguished by treelike or fingerlike morphology. Colonies on C4 agar, at 3-4 days, reach 1mm in diameter are circular, raised, & translucent with opaque centers of gray or white. Edges are entire or lobate. Mature colonies are tenacious and cohesive and can be lifted from agar surface intact with a needle. Zoogloea are not fastidious nutritionally and may be cultured on a variety of organic carbon sources in a simple defined media. Actively mobile, Zoogloea ramigera has a single polar flagellum. This bacteria forms characteristic cell aggregates surrounded by gellatinous matrices, called zoogloeal matrices, composed if extracellular polymer strands of polysaccharides.
This organism plays an important part in waste water treatment by its ability to lower biological oxygen demand and by promoting the formation of sludge deposits. It is the typical activated sludge bacterium responsible for the formation of activated sludge flocs. High levels of Z. ramigera cells and typical morphology were often linked to overloading sewage plants. This bacteria forms compact flocs that settle to the bottom of treatment tanks and assist in the purification process.
Zoogloea ramigera is nonpathogenic.
Application to Biotechnology
It is thought that Zoogloea ramigera is an indicator orgainsm for organic polluted environments and waste water. However, this does not seem to be universally true. Poly-B-hydroxbutyrate, a key component in the manufacture of biodegradable platics, is a product of Zoogloea ramigera when carbon sources are in abundance with the enzyme B-ketothiolase. Zoogloea ramigera is used in the bioaorption of metals in water sources. By recombiant DNA technology, isolation of the complete thiolase gene sequence has been successful.
The gene coding for the biosynthetic thiolase from Zoogloea ramgera has been isolated by using antibody screening methods to direct its expression in Escheria coli under transcriptional control of the lac promoter. (Peoples, Masamune, Walsh, Sinskey – 1986)
Zoogloea ramgera has long been considered the typical activated sludge bacterium responsible for the formation of activated sludge flocs. Findings indicate relatively high levels of Z. ramigera cells and typical morphology tended to be linked to overloading sewage plants. (Rossello-Mora, Wagner, Amann, Schleifer – 1994)
The taxonomic position of a misclassified strain, Zoogloea ramigera IAM 12760T was reevaluated. Based on the phenotypic and phylogenetic information, it was proposed that this organism should be reclassified in a new taxon with the name Duganella zoogloeoides gen. nov., sp. Nov. (Hiraishi, Shin, Sugiyama - 1997)
Hiraishi, A., Shin, Y. K., Sugiyama, J. “Proposal To Reclassify Zoogloeal ramigera IAM 12670 (P. R. Dugan 115) as Duganella zoogloeoides gen. nov., sp. nov.” International Journal of Systematic Bacteriology. Oct. 1997., Volume 47, No. 4, p. 1249-1251.
Rossello-Mora, R.A., Wagner, M., Amann, R., Schleifer, K. H. “The Abundance of Zoogloea ramigera in Sewage Treatment Plants.” Applied and Environmental Microbiology. Feb. 1995, Volume 61, No. 2, p. 702-705.
Peoples, O. P., Masamune, S., Walsh, C. T., Sinskey, A. J. “Biosynthetic Thiolase from Zoogloea ramigera.” The Journal of Biological Chemistry. 1987. Volume 262, No.1 p. 97-102.
Banks, M., Zoogloea ramigera. http://web.umr.edu/~microbio/BIO221_2001/zoogleoa_ramigera.html.
Friedman, B. A., Dugan, P. R. “Identification of the Zoogloea species and the Relationship of Zoogloeal Matrix and Floc Formation.” Journal of Bacteriology. May 1968. Vol. 95, No. 5 p. 1903-1909.
Korean Agriculture Culture Collection. http://kacc.rda.go.kr/eng/menu2/2_1_result_det.asp?page=1&slt_ser=sc&spe=&gen=z&ck=Zoogloea%3Bramigera%3B.
Bauman, R. W., Microbiology. 2004. p. 333.
Bergy, D. H., Holt, J. G. Bergey's Manual of Derteminative Bacteriology. p. 101. http://books.google.com/books?id=jtMLzaa5ONcC&pg=PA101&dq=Bergey%27s+Manual+of+Determinative+Bacteriology+zoogloea+ramigera&sig=8he0LYi4fN8u-HUPXQIqJku3LjE
Garity, G. M. Bergey's Systematic Bacteriology. 2005. Springer. p 913-917. http://books.google.com/books?id=9cwgo-9IyTUC&pg=RA1-PA918&dq=zoogloea+ramigera&sig=m-4te_DDhwyeNqosRgT5rMQpu-w