title: Distribution of chitin/chitosan-like bioflocculant-producing potential in the genus Citrobacter.
abstract: Some strains belonging to the genera Citrobacter and Enterobacter have been reported to produce chitin/chitosan-like bioflocculants (BFs) from acetate. In this study, to investigate the distribution of the BF-producing potential in the genus Citrobacter and to screen stably and highly BF-producing strains, we obtained 36 Citrobacter strains from different culture collection centers, which were distributed among seven species in the genus, and tested for the flocculating activities of their culture supernatants using a kaolin suspension method. As a result, 21 strains belonging to C. freundii (17 strains in 23 strains tested), C. braakii (two in two), C. youngae (one in one), and C. werkmanii (one in two) showed flocculating activity, but this ability was limited to cells grown on acetate. Gas chromatography/mass spectrometry (GC/MS) analysis of the hydrolysates from the BFs of five selected strains indicated that they consisted of glucosamine and/or N-acetylglucosamine, such as the chitin/chitosan-like BF (BF04) produced by Citrobacter sp. TKF04 (Fujita et al. J Biosci Bioeng 89: 40-46, 2000). Gel filtration chromatography using a high-performance liquid chromatography system revealed that the molecular weight ranges of these BFs varied, but the average sizes were all above 1.66 × 10⁶Da.
authors: Department of Materials Science and Chemistry, Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo, 671-2280, Japan.
authors: Kazuyuki
authors: K
authors: Kimura
authors: Takuya
authors: T
authors: Inoue
authors: Dai-Ichiro
authors: D
authors: Kato
authors: Seiji
authors: S
authors: Negoro
authors: Michihiko
authors: M
authors: Ike
authors: Masahiro
authors: M
authors: Takeo
mesh_terms: D000085:Acetates / Q000378:metabolism; D002686:Chitin / Q000737:chemistry / Q000378:metabolism*; D048271:Chitosan / Q000737:chemistry / Q000378:metabolism*; D002850:Chromatography, Gel; D002954:Citrobacter / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D005427:Flocculation; D008401:Gas Chromatography-Mass Spectrometry; D005944:Glucosamine / Q000032:analysis; D008969:Molecular Sequence Data; D008970:Molecular Weight; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D000085:Acetates; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D002686:Chitin; D048271:Chitosan; D005944:Glucosamine