title: Biodiversity and physiological characteristics of Antarctic and Arctic lichens-associated bacteria.
abstract: The diversity and physiological characteristics of culturable bacteria associated with lichens from different habitats of the Arctic and Antarctica were investigated. The 68 retrieved isolates could be grouped on the basis of their 16S rRNA gene sequences into 26 phylotypes affiliated with the phyla Actinobacteria, Bacteroidetes, Deinococcus-Thermus, and Firmicutes and with the classes Alphaproteobacteria, Betaproteobacteria, and Gammaproteobacteria. Isolates belonging to the Alphaproteobacteria were the most abundant, followed by those belonging to Actinobacteria, Betaproteobacteria, Gammaproteobacteria, Bacteroidetes, Firmicutes, and Deinococcus-Thermus. Phylogenetic analysis showed that approximately 21 % of the total isolates represented a potentially novel species or genus (≤97 % sequence similarity). Strains belonging to the genera Sphingomonas, Frondihabitans, Hymenobacter, and Burkholderia were recovered from lichen samples from both geographic locations, implying common and important bacterial functions within lichens. Extracellular protease activities were detected in six isolates, affiliated with Burkholderia, Frondihabitans, Hymenobacter, Pseudomonas, and Rhodanobacter. Extracellular lipase activities were detected in 37 isolates of the genera Burkholderia, Deinococcus, Frondihabitans, Pseudomonas, Rhodanobacter, Sphingomonas, and Subtercola. This is the first report on the culturable bacterial diversity present within lichens from Arctic and Antarctica and the isolates described herein are valuable resources to decode the functional and ecological roles of bacteria within lichens. In addition, the low similarity (≤97 %) of the recovered isolates to known species and their production of cold-active enzymes together suggest that lichens are noteworthy sources of novel bacterial strains for use in biotechnological applications.
authors.affiliation: Division of Polar Life Sciences, Korea Polar Research Institute, 26 Songdomirae-ro, Yeonsu-gu, Incheon, 406-840, Republic of Korea, ymlee@kopri.re.kr.
authors.forename: Yung Mi
authors.initials: YM
authors.lastname: Lee
authors.forename: Eun Hye
authors.initials: EH
authors.lastname: Kim
authors.forename: Hong Kum
authors.initials: HK
authors.lastname: Lee
authors.forename: Soon Gyu
authors.initials: SG
authors.lastname: Hong
mesh_terms: D000864:Antarctic Regions; D001110:Arctic Regions; D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D018407:Bacterial Physiological Phenomena; D001426:Bacterial Proteins / Q000235:genetics; D044822:Biodiversity; D008011:Lichens / Q000145:classification / Q000382:microbiology*; D008049:Lipase / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D012329:RNA, Bacterial / Q000032:analysis; D012336:RNA, Ribosomal, 16S / Q000032:analysis
chemical_list: D001426:Bacterial Proteins; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D008049:Lipase