title: Identification and characterization of thermophilic Synechococcus spp. isolates from Asian geothermal springs.
abstract: Two thermophilic cyanobacterial strains, Ts and Bs, collected from Asian geothermal springs were identified morphologically and phylogenetically as Synechococcus in the order Chroococcales and were isolated into axenic cultures. In addition to the high similarities between their full 16S rRNA gene sequences, both strains also shared similar pigment profiles and fatty acid compositions but with varied ratios. Strain Ts had elevated levels of photoprotective pigments such as carotenoid and scytonemin even after prolonged culture under identical laboratory conditions, whereas strain Bs produced more chlorophyll a per unit cell volume, perhaps resulting from UV adaptation in the natural habitats. In addition, strain Ts had more content than strain Bs in terms of the total fatty acids and the proportion of unsaturated fatty acids. Neither isolate was able to fix nitrogen, and they had zero susceptibility to ampicillin and streptomycin.
authors.affiliation: Department of Ecology and Biodiversity, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China. hongmeijing@hotmail.com
authors.forename: Hongmei
authors.initials: H
authors.lastname: Jing
authors.forename: Hongbin
authors.initials: H
authors.lastname: Liu
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Pointing
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis; D005227:Fatty Acids / Q000032:analysis; D020459:Genes, rRNA; D045482:Hot Springs / Q000382:microbiology*; D009586:Nitrogen Fixation; D010788:Photosynthesis; D010802:Phylogeny; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D046940:Synechococcus / Q000737:chemistry / Q000145:classification / Q000302:isolation & purification* / Q000502:physiology
chemical_list: D001426:Bacterial Proteins; D005227:Fatty Acids; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S