Isolation and identification of an epibiotic bacterium associated with heterocystous Anabaena cells

Author Posting. © Marine Biological Laboratory, 2006. This article is posted here by permission of Marine Biological Laboratory for personal use, not for redistribution. The definitive version was published in Biological Bulletin 210 (2006): 73-77.Heterotrophic bacteria are commonly found in close associations with photosynthetic cyanobacteria in aquatic ecosystems. Some of these associations can be species-specific and mutualistic, resulting in optimal growth and nitrogen-fixing potential for the cyanobacteria. A two-membered culture, consisting of a heterotrophic, epibiotic bacterium attached to an Anabaena sp. was studied in the work reported here. The epibiotic bacterium was grown in pure culture, and both organisms were identified on the basis of their 16S rRNA gene sequence. The specificity of the epibiont for the Anabaena sp. heterocysts was confirmed by re-association experiments. The epibiont is a member of the Alphaproteobacteria in the order Rhizobiales, with close relatives that include a group of aerobic anoxygenic photosynthetic marine isolates commonly associated with dinoflagellate phytoplankton. The close association of the epibiotic bacterium with its Anabaena host, and its phylogenic affiliation allude to the evolutionary history of association with photosynthetic organisms for a group of Rhizobia and warrant further investigation

Complete genome sequences of two phylogenetically distinct Nitrospina strains isolated from the Atlantic and Pacific Oceans

This paper is not subject to U.S. copyright. The definitive version was published in Bayer, B., Kellom, M., Valois, F., Waterbury, J., & Santoro, A. Complete genome sequences of two phylogenetically distinct Nitrospina strains isolated from the Atlantic and Pacific Oceans. Microbiology Resource Announcements, 11(5), (2022): e00100–e00122, https://doi.org/10.1128/mra.00100-22.The complete genome sequences of two chemoautotrophic nitrite-oxidizing bacteria of the genus Nitrospina are reported. Nitrospina gracilis strain Nb-211 was isolated from the Atlantic Ocean, and Nitrospina sp. strain Nb-3 was isolated from the Pacific Ocean. We report two highly similar ~3.07-Mbp genome sequences that differ by the presence of ferric iron chelator (siderophore) biosynthesis genes.This work was supported by a Simons Foundation Early Career Investigator Award (3435889) and a U.S. National Science Foundation award OCE-1924512 to A.E.S. B.B. was supported by the Austrian Science Fund (FWF) project number J4426-B. The work conducted by the U.S. Department of Energy Joint Genome Institute, a DOE Office of Science User Facility, is supported under contract number DE-AC02-05CH11231. These data were generated for JGI proposal number 506203 to B.B. and A.E.S

Teredinibacter turnerae gen. nov., sp. nov., a dinitrogen-fixing, cellulolytic, endosymbiotic c-proteobacterium isolated from the gills of wood-boring molluscs (Bivalvia: Teredinidae)

Author Posting. © Society for General Mircobiology, 2002. This article is posted here by permission of Society for General Mircobiology for personal use, not for redistribution. The definitive version was published in International Journal of Systematic Bacteriology 52 (2002): 2261-2269, doi:10.1099/ijs.0.02184-0.A cellulolytic, dinitrogen-fixing bacterium isolated from the gill tissue of a wood-boring mollusc (shipworm) Lyrodus pedicellatus of the bivalve family Teredinidae and 58 additional strains with similar properties, isolated from gills of 24 bivalve species representing 9 of 14 genera of Teredinidae, are described. The cells are Gram-negative, rigid, rods (0<4–0<6x3–6 lm) that bear a single polar flagellum. All isolates are capable of chemoheterotrophic growth in a simple mineral medium supplemented with cellulose as a sole source of carbon and energy. Xylan, pectin, carboxymethylcellulose, cellobiose and a variety of sugars and organic acids also support growth. Growth requires addition of combined nitrogen when cultures are vigorously aerated, but all isolates fix dinitrogen under microaerobic conditions. The pH, temperature and salinity optima for growth were determined for six isolates and are approximately 8<5, 30–35 °C and 0<3 M NaCl respectively. The isolates are marine. In addition to NaCl, growth requires elevated concentrations of Ca2M and Mg2M that reflect the chemistry of seawater. The DNA GMC content ranged from 49 to 51 mol%. Four isolates were identical with respect to small-subunit rRNA sequence over 891 positions compared and fall within a unique clade in the c-subclass of the Proteobacteria. Based on morphological, physiological and phylogenetic characteristics and specific symbiotic association with teredinid bivalves, a new genus and species, Teredinibacter turnerae gen. nov., sp. nov., is proposed. The type strain is T7902T (vATCC 39867TvDSM 15152T).This work was supported by grants from the National Science Foundation no. NSF DEB-9420051 and IBN- 9982982, the Maine Science and Technology Foundation's Center for Innovation in Biotechnology, and the University of Maine's Faculty Research program

Modeling Current and Future Potential Distributions of Milkweeds and the Monarch Butterfly in Idaho

Monarch butterflies (Danaus plexippus) are widespread in North America but have experienced large rangewide declines. Causes of recent declines likely involve multiple biotic and abiotic stressors including climate change and loss and degradation of native milkweed (Asclepias spp.), monarchs' obligate larval host plant. Recent broad-scale modeling efforts suggest milkweed and monarch distributions in the eastern United States will expand northward during summer months while fine-scale modeling of western population overwintering sites in California indicate shifts inland and upward in elevation. However, species' response to climate measures varies at sub-regional scales across its range and both the impacts of climate change and potential adaptation measures may be sensitive to the spatial scale of climate data used, particularly in areas of complex topography. Here, we develop fine-scale models of monarch breeding habitat and milkweed distributions in Idaho, an area at the northern extent of the monarch breeding range in North America and important in western overwintering population recruitment. Our models accurately predict current distributions for showy milkweed (A. speciosa), swamp milkweed (A. incarnata), and monarch with AUC (area under the receiver operating characteristic curve) = 0.899, 0.981, and 0.929, respectively. Topographic, geographic, edaphic, and climatic factors all play important roles in determining milkweed and, thus, monarch distributions. In particular, our results suggest that at sub-regional and fine-scales, non-climatic factors such as soil depth, distance to water, and elevation contribute significantly. We further assess changes in potential habitat across Idaho under mid-21st century climate change scenarios and potential management implications of these changing distributions. Models project slight decreases (−1,318 km2) in potential suitable habitat for showy milkweed and significant increases (+5,830 km2) for swamp milkweed. Projected amounts of suitable habitat for monarch are likely to remain roughly stable with expansion nearly equal to contraction under a moderate scenario and slightly greater when under the more severe scenario. Protected areas encompass 8% of current suitable habitat for showy milkweed, 11% for swamp milkweed, and 9% for monarch. Our study shows that suitable habitat for monarchs and/or milkweeds will likely continue to be found in managed areas traditionally seen as priority habitats in Idaho through mid-century

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