title: 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 degrees C (optimum: 25-30 degrees C) 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)omega7c 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) (=KCTC 22084(T)=DSM 19389(T)).
authors.affiliation: Department of Life Science, Chung-Ang University, Seoul 156-756, Republic of Korea.
authors.forename: Yongqi
authors.initials: Y
authors.lastname: Shao
authors.forename: Bok Sil
authors.initials: BS
authors.lastname: Chung
authors.forename: Seung Sik
authors.initials: SS
authors.lastname: Lee
authors.forename: Woojun
authors.initials: W
authors.lastname: Park
authors.forename: Sang-Suk
authors.initials: SS
authors.lastname: Lee
authors.forename: Che Ok
authors.initials: CO
authors.lastname: Jeon
mesh_terms: D015373:Bacterial Typing Techniques; D001482:Base Composition; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D005427:Flocculation; D020459:Genes, rRNA; D007723:Korea; D008969:Molecular Sequence Data; D009586:Nitrogen Fixation; D009693:Nucleic Acid Hybridization; D010641:Phenotype; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S; D017422:Sequence Analysis, DNA; D012722:Sewage / Q000382:microbiology*; D013045:Species Specificity; D014865:Waste Disposal, Fluid / Q000379:methods*; D015045:Zoogloea / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D012722:Sewage