title: Molecular characterization of hot spring cyanobacteria and evaluation of their photoprotective compounds.
abstract: Phylogenetic analysis of 4 cyanobacterial strains isolated from hot springs in Rajgir, India, was carried out using the 16S rRNA gene (1400 bp). These strains were identified as members of Chroococcales ( Cyanothece  sp. strain HKAR-1) and Nostocales ( Nostoc  sp. strain HKAR-2,  Scytonema  sp. strain HKAR-3, and  Rivularia  sp. strain HKAR-4). Furthermore, we evaluated the presence of ultraviolet-screening and (or) photoprotective compounds, such as mycosporine-like amino acids (MAAs) and scytonemin, in these cyanobacteria by using high-performance liquid chromatography. Well-characterized MAAs, including the critical and highly polar compounds shinorine, porphyra-334, and mycosporine-glycine, as well as several unknown MAAs, were found in these hot-spring-inhabiting microorganisms. The presence of scytonemin was detected only in Scytonema sp. strain HKAR-3 and Rivularia sp. strain HKAR-4. The results indicate that hot spring cyanobacteria, namely Cyanothece, Nostoc, Scytonema, and Rivularia, belonging to different groups possess various photoprotective compounds to cope up with the negative impacts of damaging radiations.
authors.affiliation: Laboratory of Photobiology and Molecular Microbiology, Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi-221005, India.
authors.forename: Rajesh P
authors.initials: RP
authors.lastname: Rastogi
authors.forename: Sunita
authors.initials: S
authors.lastname: Kumari
authors.lastname: Richa
authors.forename: Taejun
authors.initials: T
authors.lastname: Han
authors.forename: Rajeshwar P
authors.initials: RP
authors.lastname: Sinha
mesh_terms: D000596:Amino Acids / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D002851:Chromatography, High Pressure Liquid; D000458:Cyanobacteria / Q000737:chemistry* / Q000145:classification / Q000235:genetics / Q000378:metabolism; D003512:Cyclohexanones / Q000378:metabolism; D003514:Cyclohexylamines / Q000378:metabolism; D005998:Glycine / Q000031:analogs & derivatives / Q000378:metabolism; D045482:Hot Springs / Q000382:microbiology*; D007194:India; D007211:Indoles / Q000378:metabolism; D010636:Phenols / Q000378:metabolism; D010802:Phylogeny; D010860:Pigments, Biological / Q000737:chemistry / Q000378:metabolism; D013473:Sunscreening Agents / Q000737:chemistry / Q000378:metabolism*
chemical_list: D000596:Amino Acids; D003512:Cyclohexanones; D003514:Cyclohexylamines; D007211:Indoles; D010636:Phenols; D010860:Pigments, Biological; D013473:Sunscreening Agents; C421025:porphyra-334; C083368:scytonemin; C494891:shinorine; D005998:Glycine