Characterization of three spiral-shaped purple nonsulfur bacteria isolated from coastal lagoon sediments, saline sulfur springs, and microbial mats: emended description of the genus Roseospira and description of Roseospira marina sp. nov., Roseospira navarrensis sp. nov., and Roseospira thiosulfatophila sp. nov.

Abstract

Three new spirilloid phototrophic purple nonsulfur bacteria were isolated in pure culture from three different environments: strain CE2105 from a brackish lagoon in the Arcachon Bay (Atlantic coast, France), strain SE3104 from a saline sulfur spring in the Pyrenees (Navarra, Spain), and strain AT2115 a microbial mat (Tetiaroa Atoll, Society Islands). Single cells of the three strains were spiral-shaped and highly motile. Their intracellular photosynthetic membranes were of the vesicular type. Bacteriochlorophyll a and carotenoids of the normal spirilloxanthin series were present as photosynthetic pigments. Optimal growth occurred under photoheterotrophic conditions and in the presence of 0.5-4% w/v NaCl. These features are similar to those described for Roseospira mediosalina. Comparative sequence analysis of their 16S rRNA genes placed these strains within the alpha-subclass of Proteobacteria, in a cluster together with Roseospira mediosalina and Rhodospira trueperi. They form a closely related group of slightly to moderately halophilic spiral-shaped purple nonsulfur bacteria.However, the three new isolates exhibited some differences in their physiology and genetic characteristics. Consequently, we propose that they are members of three new species within the genus Roseospira, Roseospira marina sp. nov., Roseospira navarrensis sp. nov., and Roseospira thiosulfatophila sp. nov., with strains CE2105, SE3104, and AT2115 as the type strains, respectively. As a consequence, an emended description of the genus Roseospira is also given.

Spatial structure of the microbial community in sandy carbonate sediment

“…The Caulobacterales and Sphingomonadaceae consist mainly of chemoorganotrophic, aerobic organisms. Members of the Rhodospirillaceae and the 'Rhodobacterales' are notoriously versatile in their metabolism, and several genera are able to alternate between phototrophic and chemoorganotrophic growth (Imhoff 2001, Guyoneaud et al 2002. A few clones were affiliated with the 'Burkholderiales', which includes phototrophs, chemolithotrophs, methylotrophs, chemoorganotrophs, and nitrogen-fixing organisms, as well as several human, animal, and plant pathogens.…”

Roseospira visakhapatnamensis sp. nov. and Roseospira goensis sp. nov.

“…Differentiating characteristics of species of the genus Roseospira Taxa: 1, Roseospira marina; 2, Roseospira navarrensis; 3, 'Roseospira thiosulfatophila'; 4, Roseospira mediosalina (Kompantseva and Gorlenko, 1984); 5, strain JA131 T ; 6, strain JA135 T . Data for taxa 1-3 are from Guyoneaud et al (2002). +, Substrate utilized or present; 2, substrate not utilized or absent; (+), weak growth; m, growth under micro-oxic conditions; ND, not determined.…”

“…Another species of the genus Roseospira, 'Roseospira thiosulfatophila', has been proposed (Guyoneaud et al, 2002) T was isolated from an enrichment culture containing 2 % NaCl and strain JA135 T was isolated from an enrichment containing 8 % NaCl. Subsequent culturing, purification and characterization were performed in Biebl & Pfennig (1981) medium with the following modifications (l 21 ); 1 g MgSO 4 .…”

Tagaea marina gen. nov., sp. nov., a marine bacterium isolated from shallow coastal water

“…Members of the genera Phaeospirillum and Rhodospirillum, and some species in other genera including Rhodocista centenaria, Roseospira marina and Rhodospirillum photometricum, prefer phototroheterotrophic growth under anoxic conditions in the light, and alternatively, can conduct chemoheterotrophic growth in the dark under oxic or microoxic conditions (Nissen & Dundas, 1984;Mack et al, 1993;Imhoff et al, 1998;Kawasaki et al, 1992;Garrity et al, 2005). Other species of the genera Roseospira and Rhodospirillum, such as Roseospira mediosalina, Roseospira navarrensis and Rhodospirillum rubrum, are capable of photoautotrophic growth, together with the above growth patterns (Guyoneaud et al, 2002;Garrity et al, 2005). Obligate chemotrophs in the family Rhodospirillaceae include aerobic and microaerophilic genera such as Azospirillum, Conglomeromonas, Defluviicoccus, Inquilinus, Magnetospirillum, Oceanibaculum, Thalassospira, Tistlia and Tistrella (Tarrand et al, 1978;Skerman et al, 1983;Schleifer et al, 1991;Coenye et al, 2002;Ló pez-Ló pez et al, 2002;Shi et al, 2002;Maszenan et al, 2005;Lai et al, 2009;Díaz-Cárdenas et al, 2010), and facultatively anaerobic genera such as Caenispirillum, Fodinicurvata, Nisaea, Skermanella, Telmatospirillum and Thalassobaculum (Sly & Stackebrandt, 1999;Sizova et al, 2007;Yoon et al, 2007;Zhang et al, 2008;Urios et al, 2008;Wang et al, 2009).…”