title: High Life Expectancy of Bacteria on Lichens.
abstract: Self-sustaining lichen symbioses potentially can become very old, sometimes even thousands of years in nature. In the joint structures, algal partners are sheltered between fungal structures that are externally colonized by bacterial communities. With this arrangement lichens survive long periods of drought, and lichen thalli can be revitalized even after decades of dry storage in a herbarium. To study the effects of long-term ex situ storage on viability of indigenous bacterial communities we comparatively studied herbarium-stored material of the lung lichen, Lobaria pulmonaria. We discovered that a significant fraction of the lichen-associated bacterial community survives herbarium storage of nearly 80 years, and living bacteria can still be found in even older material. As the bacteria reside in the upper surface layers of the lichen material, we argue that the extracellular polysaccharides of lichens contribute to superior life expectancy of bacteria. Deeper understanding of underlying mechanisms could provide novel possibilities for biotechnological applications.
authors.affiliation: Institute of Environmental Biotechnology, Graz University of Technology, Petersgasse 12, 8010, Graz, Austria.
authors.forename: Tomislav
authors.initials: T
authors.lastname: Cernava
authors.affiliation: Institute of Environmental Biotechnology, Graz University of Technology, Petersgasse 12, 8010, Graz, Austria.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Berg
authors.affiliation: Institute of Plant Sciences, University of Graz, Holteigasse 6, 8010, Graz, Austria. martin.grube@uni-graz.at.
authors.forename: Martin
authors.identifier: 0000-0001-6940-5282
authors.initials: M
authors.lastname: Grube
mesh_terms: D001203:Ascomycota / Q000502:physiology; D001419:Bacteria / Q000235:genetics; D018407:Bacterial Physiological Phenomena; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D005798:Genes, Bacterial; D008011:Lichens / Q000382:microbiology*; D008017:Life Expectancy; D018613:Microscopy, Confocal; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D013534:Survival; D013559:Symbiosis
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S
keywords: Herbarium; Lichen-associated bacteria; Lobaria pulmonaria; Storage; Survival; Thallus