Zoogloea caeni sp. nov., a floc-forming bacterium isolated from activated sludge

Abstract

Two floc-forming, nitrogen-fixing bacteria, strains EMB43 T and EMB61, obtained from activated sludge of a domestic wastewater treatment plant in Korea, were characterized. The two strains were very closely related, sharing 99.7 % 16S rRNA gene sequence similarity and showing a level of DNA-DNA relatedness of 93 %, which suggests that they represent members of a single species. Phylogenetic analysis based on 16S rRNA gene sequences showed that the two novel isolates formed a distinct phyletic lineage within the genus Zoogloea and were related most closely to Zoogloea resiniphila DhA-35 T and Zoogloea oryzae A-7 T , with sequence similarities of 97.2 %. Levels of DNA-DNA relatedness between strain EMB43 T and Z. resiniphila DhA-35 T and Z. oryzae A-7 T were 12.8 and 7.4 %, respectively. Cells of strains EMB43 T and EMB61 were facultatively aerobic, rod-shaped, Gram-negative and motile by means of a polar flagellum. The strains grew at temperatures of 15-40 6C (optimum: 25-30 6C) and at pH 6.0-9.0 (optimum: pH 6.5-7.5). The predominant fatty acids were C 16 : 0 , C 10 : 0 3-OH and summed feature 3 (C 16 : 1 v7c and/or iso-C 15 : 0 2-OH), and the predominant polar lipid was phosphatidylethanolamine. The genomic DNA G+C content was 64.9-65.0 mol% and the major isoprenoid quinone was ubiquinone-8 (Q-8). On the basis of phenotypic, chemotaxonomic and molecular data, the isolates are considered to represent a novel species of the genus Zoogloea, for which the name Zoogloea caeni sp. nov. is proposed. The type strain is EMB43 T (5KCTC 22084 T 5DSM 19389 T ).Bacteria of the genus Zoogloea, a member of the family Rhodocyclaceae, are known to form characteristic cell aggregates embedded in gelatinous matrices, often called zoogloeal matrices (Dugan et al., 1992). Historically, the criteria used for taxonomic classification in this genus were based on phenotypic characteristics, which has resulted in confusion in identifying members of the genus and led to Zoogloea ramigera ATCC 25935 (5IAM 12670) being transferred to Duganella zoogloeoides based on molecular approaches (Hiraishi et al., 1997). At the time of writing, the genus Zoogloea comprises three recognized species, namely Z. ramigera (Crabtree & McCoy, 1967), Zoogloea resiniphila (Mohn et al., 1999) and Zoogloea oryzae (Xie & Yokota, 2006). Activated-sludge processes have been used to remove organic compounds as well as nutrients from wastewater, and insight into the bacterial communities is a prerequisite for understanding activated-sludge processes. Therefore, efforts have been made in our laboratory to isolate and characterize members of the bacterial community in activated sludge (Jeon et al., 2003;Lu et al., 2006;Park et al., 2007;Ryu et al., 2007). In the present study, we describe a novel species of the genus Zoogloea isolated from an activated-sludge process treating domestic sewage.Strains EMB43 T and EMB61 were isolated from activated sludge of a domestic wastewater treatment plant in Pohang,The GenBank/EMBL/DDBJ accession numbers for the 16S rRNA gene seq...

Dynamics of Microbial Community Structure of and Enhanced Biological Phosphorus Removal by Aerobic Granules Cultivated on Propionate or Acetate

“…1A). The dominant T-RF in the propionate granules with about 40% relative abundance was affiliated with the genus Zoogloea, being 99% similar to clones from activated sludge and with the closest isolate being the floc-forming bacterium Zoogloea caeni (50). Other detected important T-RFs were affiliated with Acidovorax-like and Thiothrix-like bacteria, with relative abundances of around 12% each, as well as Accumulibacter-like bacteria, at about 7% abundance.…”

Antibiotic resistance genes in an urban river as impacted by bacterial community and physicochemical parameters

“…The relative abundance of Burkholderia was significantly correlated with ARGs (aminoglycoside, beta-lactams, MLSB, sulfonamide, and tetracycline resistance genes) and transposases (Table S3; P < 0.01), demonstrating that MGEs and ARGs were prevalent in zoonotic bacteria. Among all sites, site C1 had the highest abundance of several bacteria (e.g., Zoogloea, Bacteroides, and Prevotalla), and Zoogloea species that commonly exist in wastewater and play a crucial role in organismal remediation in wastewater treatment (Garrity et al 2005;Shao et al 2009). This suggests that site C1 may be receiving large inputs of sewage waste, consistent with the extremely high NH 4 + concentration (16.4 mg NH 4 -N/L) at this site.…”

Understanding the Linkage between Elevation and the Activated-Sludge Bacterial Community along a 3,600-Meter Elevation Gradient in China

“…For instance, Dechloromonas is frequently reported as a phosphate-accumulating organism in enhanced biological phosphorus removal reactors (9). Zoogloea is the main agent for the flocculation of activated sludge by forming extracellular gelatinous matrices (25,26). Achromobacter can effi- (27) and polycyclic aromatic hydrocarbons (28).…”