TY - JOUR A1 - Ardissone, S. A1 - Kobayashi, H. A1 - Kambara, K. A1 - Rummel, C. A1 - Noel, K.D. A1 - Walker, G.C. A1 - Broughton, William J. A1 - Deakin, W.J. T1 - Role of BacA in lipopolysaccharide synthesis, peptide transport, and nodulation by rhizobium sp. strain NGR234 N2 - BacA of Sinorhizobium meliloti plays an essential role in the establishment of nitrogen-fixing symbioses with Medicago plants, where it is involved in peptide import and in the addition of very-long-chain fatty acids (VLCFA) to lipid A of lipopolysaccharide (LPS). We investigated the role of BacA in Rhizobium species strain NGR234 by mutating the bacA gene. In the NGR234 bacA mutant, peptide import was impaired, but no effect on VLCFA addition was observed. More importantly, the symbiotic ability of the mutant was comparable to that of the wild type for a variety of legume species. Concurrently, an acpXL mutant of NGR234 was created and assayed. In rhizobia, AcpXL is a dedicated acyl carrier protein necessary for the addition of VLCFA to lipid A. LPS extracted from the NGR234 mutant lacked VLCFA, and this mutant was severely impaired in the ability to form functional nodules with the majority of legumes tested. Our work demonstrates the importance of VLCFA in the NGR234-legume symbiosis and also shows that the necessity of BacA for bacteroid differentiation is restricted to specific legume-Rhizobium interactions. KW - Bacteria KW - Rhizobia PY - 2011 U6 - https://doi.org/10.1128/JB.01260-10 SN - 0021-9193 SN - 1098-5530 VL - 193 IS - 9 SP - 2218 EP - 2228 PB - American Society for Microbiology CY - Washington, DC AN - OPUS4-24267 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Del Carmen Montero-Calasanz, M. A1 - Göker, M. A1 - Broughton, W.J. A1 - Cattaneo, A. A1 - Favet, J. A1 - Pötter, G. A1 - Rohde, M. A1 - Spröer, C. A1 - Schumann, P. A1 - Klenk, H.-P. A1 - Gorbushina, Anna T1 - Geodermatophilus tzadiensis sp. nov., a UV radiation-resistant bacterium isolated from sand of the Saharan desert N2 - Three novel Gram-positive, aerobic, actinobacterial strains, CF5/2T, CF5/1 and CF7/1, were isolated in 2007 during environmental screening of arid desert soil in the Sahara desert, Chad. Results from riboprinting, MALDI-TOF protein spectra and 16S rRNA sequence analysis confirmed that all three strains belonged to the same species. Phylogenetic analysis of 16S rRNA sequences with the strains' closest relatives indicated that they represented a distinct species. The three novel strains also shared a number of physiological and biochemical characteristics distinct from previously named Geodermatophilus species. The novel strains' peptidoglycan contained meso-diaminopimelic acid; their main phospholipids were phosphatidylcholine, phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylinositol and a small amount of phosphatidylglycerol; MK-9(H4) was the dominant menaquinone. The major cellular fatty acids were the branched-chain saturated acids iso-C16:0 and iso-C15:0. Galactose was detected as diagnostic sugar. Based on these chemotaxonomic results, 16S rRNA gene sequence analysis and DNA–DNA hybridization between strain CF5/2T and the type strains of Geodermatophilus saharensis, Geodermatophilus arenarius, Geodermatophilus nigrescens, Geodermatophilus telluris and Geodermatophilus siccatus, the isolates CF5/2T, CF5/1 and CF7/1 are proposed to represent a novel species, Geodermatophilus tzadiensis, with type strain CF5/2T = DSM 45416 = MTCC 11411 and two reference strains, CF5/1 (DSM 45415) and CF7/1 (DSM 45420). KW - Geodermatophilaceae KW - Actinomycetes KW - Taxonomy KW - Radiation-resistant PY - 2013 U6 - https://doi.org/10.1016/j.syapm.2012.12.005 SN - 0723-2020 VL - 36 IS - 3 SP - 177 EP - 182 PB - Elsevier CY - Amsterdam AN - OPUS4-28261 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gay-Fraret, J. A1 - Ardissone, S. A1 - Kambara, K. A1 - Broughton, William J. A1 - Deakin, W.J. A1 - Le Quéré, A. T1 - Cyclic-Beta-glucans of Rhizobium (Sinorhizobium) sp. strain NGR234 are required for hypo-osmotic adaption, motility, and efficient symbiosis with host plants N2 - Cyclic-β-glucans (CβG) consist of cyclic homo-polymers of glucose that are present in the periplasmic space of many Gram-negative bacteria. A number of studies have demonstrated their importance for bacterial infection of plant and animal cells. In this study, a mutant of Rhizobium (Sinorhizobium) sp. strain NGR234 (NGR234) was generated in the cyclic glucan synthase (ndvB)-encoding gene. The great majority of CβG produced by wild-type NGR234 are negatively charged and substituted. The ndvB mutation abolished CβG biosynthesis. We found that, in NGR234, a functional ndvB gene is essential for hypo-osmotic adaptation and swimming, attachment to the roots, and efficient infection of Vigna unguiculata and Leucaena leucocephala. KW - Cyclic Beta-(1,2)-glucans KW - Legumes KW - Osmotic adaption KW - Swimming KW - Nodulation KW - ndvB PY - 2012 U6 - https://doi.org/10.1111/j.1574-6968.2012.02595.x SN - 0378-1097 SN - 1574-6968 VL - 333 IS - 1 SP - 28 EP - 36 PB - Wiley-Blackwell CY - Malden, Mass., USA AN - OPUS4-26111 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gorbushina, Anna A1 - Broughton, W.J. T1 - Microbiology of the atmosphere-rock interface: How biological interactions and physical stresses modulate a sophisticated microbial ecosystem N2 - Life at the atmosphere-lithosphere boundary is an ancient terrestrial niche that is sparsely covered by thin subaerial biofilms. The microbial inhabitants of these biofilms (a) have adapted to all types of terrestrial/subaerial stresses (e.g., desiccation, extreme temperatures, low nutrient availability, intense solar radiation), (b) interact with minerals that serve as both a dwelling and a source of mineral nutrients, and (c) provoke weathering of rocks and soil formation. Subaerial communities comprise heterotrophic and phototrophic microorganisms that support each other's lifestyle. Major lineages of eubacteria associated with the early colonization of land (e.g., Actinobacteria, Cyanobacteria) are present in these habitats along with eukaryotes such as microscopic green algae and ascomycetous fungi. The subaerial biofilm inhabitants have adapted to desiccation, solar radiation, and other environmental challenges by developing protective, melanized cell walls, assuming microcolonial architectures and symbiotic lifestyles. How these changes occurred, their significance in soil formation, and their potential as markers of climate change are discussed below. KW - Cyanobacteria KW - Geobiology KW - Microcolonial fungi KW - Rock inhabiting KW - Fungi-phototroph symbioses KW - Soil formation KW - Subaerial biofilms KW - Weathering PY - 2009 U6 - https://doi.org/10.1146/annurev.micro.091208.073349 SN - 0066-4227 VL - 63 SP - 431 EP - 450 PB - Annual Reviews Inc. CY - Palo Alto, CA, USA AN - OPUS4-20243 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Toepfer, I. A1 - Favet, J. A1 - Schulte, A. A1 - Schmölling, M. A1 - Butte, W. A1 - Triplett, E.W. A1 - Broughton, W.J. A1 - Gorbushina, Anna T1 - Pathogens as potential hitchhikers on intercontinental dust N2 - Desert dust seeds distant lands and waters with minerals as well as micro-organisms raising the question of whether this ancient phenomenon also spreads pathogens across the globe. Severe dust storms require strong winds blowing over land-masses that are largely devoid of vegetation, effectively limiting the scope for winds to raise pathogens into the air. Nevertheless, changing patterns of land-use, often driven by belligerency, result in refugees spreading to areas that were previously deemed barely habitable. With the help of the International Committee of the Red Cross, a number of sand/dust samples were collected from the Republic of Chad, some near refugee camps, others further removed from human influence. In parallel studies, we documented the micro-organisms present in these samples and used a number of the isolates here to test the effect of environmental constraints on their ability to survive intercontinental flight. We also added traditional pathogens to the palette of microbes and tested the effects of UV irradiation, desiccation and temperature on survival of both bacteria and fungi. A clear trend was obvious—those microbes that are coloured or able to form conidia or spores (in other words, those that are native to deserts) were well able to resist the imposed stresses. On the other hand, most pathogens were more sensitive to stresses than the environmental isolates. Toxin production in two species of Aspergillus was also investigated. Short-term desiccation (simulating environmental conditions during intercontinental travel) of sand amended with fungal spores containing sterigmatocystin leads to increased mycotoxin contents, but significant mycotoxin production was only possible under growth-permissive conditions, e.g. at higher humidity. It thus seems likely that an ever-decreasing fraction of the initial pathogen load survives as the dust recedes from its desert source and that those organisms that land on other continents are highly enriched in desert dwellers. KW - Chad KW - Desert sand KW - Sterigmatocystin KW - Aspergillus sydowii KW - A. versicolor PY - 2012 U6 - https://doi.org/10.1007/s10453-011-9230-2 SN - 0393-5965 SN - 1573-3025 VL - 28 IS - 2 SP - 221 EP - 231 PB - Springer Science + Business Media B.V. CY - Dordrecht [u.a.] AN - OPUS4-24814 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -