The cellular fatty acid content of 22 cyanobacterial strains belonging to the genera Anabaena, Aphanizomenon, Calothrix, Cylindrospermum, Nostoc, Microcystis and Planktothrix were analysed. The identities of the major peaks were confirmed by MS. Correspondence analysis of the data revealed three distinct groups formed by the Microcystis strains, the Nostoc/Planktothrix strains and the Anabaena/Aphanizomenon/Cylindrospermum strains. The Calothrix strain did not cluster with the other heterocystous cyanobacteria, supporting its morphological classification separate from the Nostocaceae family. The presence of large amounts of the fatty acids 18:30omega6,9,12c and 18:0 iso distinguished the Microcystis strains from the other cyanobacteria studied. The high content of 16:1omega7c grouped the Nostoc strains with the Planktothrix strains. A free-living strain of Nostoc contained 16:1omegao5c and 16: 1omega7c (about 1: 1), separating it from the symbiotic Nostoc strain and the Planktothrix strains. the strains of Anabaena, Aphanizomenon and Cylindrospermum grouped tightly and were characterized by the presence of 16:1omega9c and 16:0 anteiso fatty acids. Correspondence analysis of Anabaena, Aphanizomenon and Cylindrospermum showed that all hepatotoxic Anabaena strains grouped together, whereas the non-toxic and neurotoxic Anabaena strains grouped with the non-toxic Aphanizomenon strains.
Sphingomonas species were commonly isolated from biofilms in drinking water distribution systems in Finland (three water meters) and Sweden (five water taps in different buildings). The Sphingomonas isolates (n = 38) were characterized by chemotaxonomic, physiological and phylogenetic methods. Fifteen isolates were designated to species Sphingomonas aromaticivorans, seven isolates to S. subterranea, two isolates to S. xenophaga and one isolate to S. stygia. Thirteen isolates represented one or more new species of Sphingomonas. Thirty‐three isolates out of 38 grew at 5 °C on trypticase soy broth agar (TSBA) and may therefore proliferate in the Nordic drinking water pipeline where the temperature typically ranges from 2 to 12 °C. Thirty‐three isolates out of 38 grew at 37 °C on TSBA and 15 isolates also grew on blood agar at 37 °C. Considering the potentially pathogenic features of sphingomonas, their presence in drinking water distribution systems may not be desirable.
Rubellimicrobium thermophilum gen. nov., sp. nov., a red-pigmented, moderately thermophilic bacterium isolated from coloured slime deposits in paper machines Six red-pigmented strains of the Alphaproteobacteria with optimal growth between 45 and 54 6C were previously isolated from coloured biofilms in two fine-paper machines and one pulp dryer. The strains were found to be resistant to 15 p.p.m. 2,2-dibromo-3-nitrilopropionamide, a common industrial biocide. 16S RNA gene sequence similarity of the isolates was 99?7-100 %. Ribotyping using the restriction enzymes PvuII and EcoRI showed that four of the isolates (C-lvk-R2A-1, C-lvk-R2A-2 T , C-R2A-52d and C-R2A-5d) belong to a single species. 16S rRNA gene-based phylogenetic analysis revealed that, together with Rhodobacter blasticus ATCC 33485 T , the isolates form a deep line of descent (94?7-94?9 % sequence similarity) within the family Rhodobacteraceae loosely affiliated with the Rhodobacter/Paracoccus clade. The isolates were strictly aerobic and oxidase-positive (catalase was weakly positive) and utilized a wide range of substrates including pentoses, hexoses, oligosaccharides and sugar alcohols. The predominant constituents in their cellular fatty acid profiles were C 19 : 0 cyclo v8c (39-44 %), C 18 : 0 (21-24 %) and C 16 : 0 (21-23 %). Fatty acids present in smaller amounts included C 18 : 1 v7c, C 10 : 0 3-OH, C 18 : 1 v7c 11-methyl, C 20 : 2 v6,9c and C 17 : 0 cyclo, amongst others. Polar lipids included diphosphatidylglycerol, phosphatidylcholine and an unidentified aminolipid, but not phosphatidylethanolamine. Carotenoid pigments were synthesized but bacteriochlorophyll a was not. The polyamine patterns consisted of the major compounds putrescine, spermidine and sym-homospermidine. The major respiratory lipoquinone was ubiquinone Q-10. The DNA G+C content was 69?4-70?2 mol%. On the basis of the phylogenetic and phenotypic evidence, the biofilm isolates were classified in a new genus, Rubellimicrobium gen. nov.; four of the isolates are assigned to the type species, Rubellimicrobium thermophilum gen. nov., sp. nov. Strain C-lvk-R2A-2 T (=CCUG 51817 T =DSM 16684 T =HAMBI 2421 T ) is the type strain of Rubellimicrobium thermophilum.Coloured microbial slime deposits (biofilms) in the wet end of paper machines are deleterious, particularly for white end products. Bacterial slime deposits on machine surfaces impair the runability of paper machines, because thick biofilms may break loose and cause web breaks or product defects such as holes and coloured spots (Blanco et al., The GenBank/EMBL/DDBJ accession numbers for the 16S rRNA gene sequences of strains A-col-R2A-4, C-lvk-R2A-2 T , C-R2A-52d, E-R2A-8a and C-lvk-R2A-1 are AJ505840 and AJ844281-AJ844284, respectively. Details of the polyamine and fatty acid profiles of the novel strains, characteristics that distinguish the strains from other similar species isolated from paper-machine biofilms, results of riboprint analysis and additional electron micrographs are available as supplementary material in IJSE...
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