title: Coaggregation among nonflocculating bacteria isolated from activated sludge.
abstract: Thirty-two strains of nonflocculating bacteria isolated from sewage-activated sludge were tested by a spectrophotometric assay for their ability to coaggregate with one other in two-membered systems. Among these strains, eight showed significant (74 to 99%) coaggregation with Acinetobacter johnsonii S35 while only four strains coaggregated, to a lesser extent (43 to 65%), with Acinetobacter junii S33. The extent and pattern of coaggregation as well as the aggregate size showed good correlation with cellular characteristics of the coaggregating partners. These strains were identified by sequencing of full-length 16S rRNA genes. A. johnsonii S35 could coaggregate with strains of several genera, such as Oligotropha carboxidovorans, Microbacterium esteraromaticum, and Xanthomonas spp. The role of Acinetobacter isolates as bridging organisms in multigeneric coaggregates is indicated. This investigation revealed the role of much-neglected nonflocculating bacteria in floc formation in activated sludge.
authors.affiliation: Department of Applied Chemistry, Faculty of Engineering, Utsunomiya University, Utsunomiya 321-8585, Japan.
authors.forename: Anushree
authors.initials: A
authors.lastname: Malik
authors.forename: Masashi
authors.initials: M
authors.lastname: Sakamoto
authors.forename: Shohei
authors.initials: S
authors.lastname: Hanazaki
authors.forename: Masamitsu
authors.initials: M
authors.lastname: Osawa
authors.forename: Takanori
authors.initials: T
authors.lastname: Suzuki
authors.forename: Masaki
authors.initials: M
authors.lastname: Tochigi
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kakii
mesh_terms: D000150:Acinetobacter / Q000502:physiology; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D001422:Bacterial Adhesion / Q000502:physiology*; D018407:Bacterial Physiological Phenomena; D004275:DNA, Ribosomal / Q000032:analysis; D005427:Flocculation; D008855:Microscopy, Electron, Scanning; D008969:Molecular Sequence Data; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012722:Sewage / Q000382:microbiology*; D014974:Xanthomonas / Q000502:physiology
chemical_list: D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D012722:Sewage