title: Gloeocapsopsis AAB1, an extremely desiccation-tolerant cyanobacterium isolated from the Atacama Desert.
abstract: The comprehensive study of microorganisms that evolved in the Atacama Desert, the driest and oldest on earth, may help to understand the key role of water for life. In this context, we previously characterized the microenvironment that allows colonization of the underside of quartzes in the Coastal Range of this desert by hypolithic microorganisms (Azua-Bustos et al. Microb Ecol 58:568-581, 2011). Now, we describe the biodiversity composition of these biofilms and the isolation from it of a new cyanobacterial strain. Based on morphologic and phylogenetic analyses, this isolate (AAB1) was classified as a new member of the Gloeocapsopsis genus. Physiological, morphological and molecular responses by isolate AAB1 show that this strain is extremely tolerant to desiccation. Our results also indicate that the isolate biosynthesizes sucrose and trehalose in response to this stressful condition. We identified two candidate genes involved in sucrose synthesis, namely sucrose 6-phosphate synthase and sucrose 6-phosphate phosphatase. Thus, the Gloeocapsopsis isolate AAB1 may represent a suitable model for understanding tolerance to low water availability.
authors.affiliation: Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Alameda 340, Santiago, Chile, ajazua@uc.cl.
authors.forename: Armando
authors.initials: A
authors.lastname: Azua-Bustos
authors.forename: Jorge
authors.initials: J
authors.lastname: Zúñiga
authors.forename: Cristián
authors.initials: C
authors.lastname: Arenas-Fajardo
authors.forename: Marcelo
authors.initials: M
authors.lastname: Orellana
authors.forename: Loreto
authors.initials: L
authors.lastname: Salas
authors.forename: Vicuña
authors.initials: V
authors.lastname: Rafael
mesh_terms: D000222:Adaptation, Physiological; D018441:Biofilms; D002677:Chile; D000458:Cyanobacteria / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D003889:Desert Climate; D003890:Desiccation; D010802:Phylogeny; D012329:RNA, Bacterial / Q000235:genetics; D012335:RNA, Ribosomal / Q000235:genetics; D012988:Soil Microbiology; D013395:Sucrose / Q000378:metabolism; D014199:Trehalose / Q000096:biosynthesis
chemical_list: D012329:RNA, Bacterial; D012335:RNA, Ribosomal; D013395:Sucrose; D014199:Trehalose