Large-scale distribution and activity patterns of an extremely low-light-adapted population of green sulfur bacteria in the Black Sea

2010 ◽  
Vol 12 (5) ◽  
pp. 1348-1362 ◽  
Author(s):  
Evelyn Marschall ◽  
Mareike Jogler ◽  
Uta Henßge ◽  
Jörg Overmann
Keyword(s):  
Black Sea ◽  
Large Scale ◽  
Activity Patterns ◽  
Green Sulfur Bacteria ◽  
The Black Sea ◽  
Low Light ◽  
Sulfur Bacteria ◽  
Green Sulfur

scholarly journals Subfossil 16S rRNA Gene Sequences of Green Sulfur Bacteria in the Black Sea and Their Implications for Past Photic Zone Anoxia

2007 ◽  
Vol 74 (3) ◽  
pp. 624-632 ◽  
Author(s):  
Ann K. Manske ◽  
Uta Henßge ◽  
Jens Glaeser ◽  
Jörg Overmann
Keyword(s):  
16S Rrna ◽  
Black Sea ◽  
Dna Sequences ◽  
Green Sulfur Bacteria ◽  
The Black Sea ◽  
Rrna Gene ◽  
Photic Zone ◽  
Low Light ◽  
Sulfur Bacteria ◽  
Green Sulfur

ABSTRACT The Black Sea is the largest extant anoxic water body on Earth. Its oxic-anoxic boundary is located at a depth of 100 m and is populated by a single phylotype of marine green sulfur bacteria. This organism, Chlorobium sp. strain BS-1, is extraordinarily low light adapted and can therefore serve as an indicator of deep photic zone anoxia (A. K. Manske, J. Glaeser, M. M. M. Kuypers, and J. Overmann, Appl. Environ. Microbiol. 71:8049-8060, 2005). In the present study, two sediment cores were retrieved from the bottom of the Black Sea at depths of 2,006 and 2,162 m and were analyzed for the presence of subfossil DNA sequences of BS-1 using ancient-DNA methodology. Using optimized cultivation media, viable cells of the BS-1 phylotype were detected only at the sediment surface and not in deeper layers. In contrast, green sulfur bacterial 16S rRNA gene fragments were amplified from all the sediment layers investigated, including turbidites. After separation by denaturing gradient gel electrophoresis and sequencing, 14 different sequence types were distinguished. The sequence of BS-1 represented only a minor fraction of the amplification products and was found in 6 of 22 and 4 of 26 samples from the 2,006- and 2,162-m stations, respectively. Besides the sequences of BS-1, three additional phylotypes of the marine clade of green sulfur bacteria were detected. However, the majority of sequences clustered with groups from freshwater habitats. Our results suggest that a considerable fraction of green sulfur bacterial chemofossils did not originate in a low-light marine chemocline environment and therefore were likely to have an allochthonous origin. Thus, analysis of subfossil DNA sequences permits a more differentiated interpretation and reconstruction of past environmental conditions if specific chemofossils of stenoec species, like Chlorobium sp. strain BS-1, are employed.

scholarly journals Physiology and Phylogeny of Green Sulfur Bacteria Forming a Monospecific Phototrophic Assemblage at a Depth of 100 Meters in the Black Sea

2005 ◽  
Vol 71 (12) ◽  
pp. 8049-8060 ◽  
Author(s):  
Ann K. Manske ◽  
Jens Glaeser ◽  
Marcel M. M. Kuypers ◽  
Jörg Overmann
Keyword(s):  
Black Sea ◽  
Sulfide Oxidation ◽  
Green Sulfur Bacteria ◽  
The Black Sea ◽  
Rrna Gene ◽  
Green Sulfur Bacterium ◽  
Sulfur Bacteria ◽  
Light Intensities ◽  
Green Sulfur

ABSTRACT The biomass, phylogenetic composition, and photoautotrophic metabolism of green sulfur bacteria in the Black Sea was assessed in situ and in laboratory enrichments. In the center of the western basin, bacteriochlorophyll e (BChl e) was detected between depths of 90 and 120 m and reached maxima of 54 and 68 ng liter−1. High-pressure liquid chromatography analysis revealed a dominance of farnesyl esters and the presence of four unusual geranyl ester homologs of BChl e. Only traces of BChl e (8 ng liter−1) were found at the northwestern slope of the Black Sea basin, where the chemocline was positioned at a significantly greater depth of 140 m. Stable carbon isotope fractionation values of farnesol indicated an autotrophic growth mode of the green sulfur bacteria. For the first time, light intensities in the Black Sea chemocline were determined employing an integrating quantum meter, which yielded maximum values between 0.0022 and 0.00075 μmol quanta m−2 s−1 at the top of the green sulfur bacterial layer around solar noon in December. These values represent by far the lowest values reported for any habitat of photosynthetic organisms. Only one 16S rRNA gene sequence type was detected in the chemocline using PCR primers specific for green sulfur bacteria. This previously unknown phylotype groups with the marine cluster of the Chlorobiaceae and was successfully enriched in a mineral medium containing sulfide, dithionite, and freshly prepared yeast extract. Under precisely controlled laboratory conditions, the enriched green sulfur bacterium proved to be capable of exploiting light intensities as low as 0.015 μmol quanta m−2 s−1 for photosynthetic 14CO2 fixation. Calculated in situ doubling times of the green sulfur bacterium range between 3.1 and 26 years depending on the season, and anoxygenic photosynthesis contributes only 0.002 to 0.01% to total sulfide oxidation in the chemocline. The stable population of green sulfur bacteria in the Black Sea chemocline thus represents the most extremely low-light-adapted and slowest-growing type of phototroph known to date.

scholarly journals Signature pigments of green sulfur bacteria in lower Pleistocene deposits from the Banyoles lacustrine area (Spain)

2005 ◽  
Vol 34 (2) ◽  
pp. 271-280 ◽  
Author(s):  
N. Mallorquí ◽  
J.B. Arellano ◽  
C.M. Borrego ◽  
L.J. Garcia-Gil
Keyword(s):  
Green Sulfur Bacteria ◽  
Sulfur Bacteria ◽  
Lower Pleistocene ◽  
Green Sulfur

scholarly journals Differential RNA Sequencing Implicates Sulfide as the Master Regulator of S 0 Metabolism in Chlorobaculum tepidum and Other Green Sulfur Bacteria

2017 ◽  
Vol 84 (3) ◽  
Author(s):  
Jacob M. Hilzinger ◽  
Vidhyavathi Raman ◽  
Kevin E. Shuman ◽  
Brian J. Eddie ◽  
Thomas E. Hanson
Keyword(s):  
Gene Expression ◽  
Elemental Sulfur ◽  
Green Sulfur Bacteria ◽  
Electron Donors ◽  
Reduced Sulfur Compounds ◽  
Promoter Elements ◽  
Content Type ◽  
Sulfur Bacteria ◽  
Chlorobaculum Tepidum ◽  
Green Sulfur

ABSTRACT The green sulfur bacteria ( Chlorobiaceae ) are anaerobes that use electrons from reduced sulfur compounds (sulfide, S 0 , and thiosulfate) as electron donors for photoautotrophic growth. Chlorobaculum tepidum , the model system for the Chlorobiaceae , both produces and consumes extracellular S 0 globules depending on the availability of sulfide in the environment. These physiological changes imply significant changes in gene regulation, which has been observed when sulfide is added to Cba. tepidum growing on thiosulfate. However, the underlying mechanisms driving these gene expression changes, i.e., the specific regulators and promoter elements involved, have not yet been defined. Here, differential RNA sequencing (dRNA-seq) was used to globally identify transcript start sites (TSS) that were present during growth on sulfide, biogenic S 0 , and thiosulfate as sole electron donors. TSS positions were used in combination with RNA-seq data from cultures growing on these same electron donors to identify both basal promoter elements and motifs associated with electron donor-dependent transcriptional regulation. These motifs were conserved across homologous Chlorobiaceae promoters. Two lines of evidence suggest that sulfide-mediated repression is the dominant regulatory mode in Cba. tepidum . First, motifs associated with genes regulated by sulfide overlap key basal promoter elements. Second, deletion of the Cba. tepidum 1277 ( CT1277 ) gene, encoding a putative regulatory protein, leads to constitutive overexpression of the sulfide:quinone oxidoreductase CT1087 in the absence of sulfide. The results suggest that sulfide is the master regulator of sulfur metabolism in Cba. tepidum and the Chlorobiaceae . Finally, the identification of basal promoter elements with differing strengths will further the development of synthetic biology in Cba. tepidum and perhaps other Chlorobiaceae . IMPORTANCE Elemental sulfur is a key intermediate in biogeochemical sulfur cycling. The photoautotrophic green sulfur bacterium Chlorobaculum tepidum either produces or consumes elemental sulfur depending on the availability of sulfide in the environment. Our results reveal transcriptional dynamics of Chlorobaculum tepidum on elemental sulfur and increase our understanding of the mechanisms of transcriptional regulation governing growth on different reduced sulfur compounds. This report identifies genes and sequence motifs that likely play significant roles in the production and consumption of elemental sulfur. Beyond this focused impact, this report paves the way for the development of synthetic biology in Chlorobaculum tepidum and other Chlorobiaceae by providing a comprehensive identification of promoter elements for control of gene expression, a key element of strain engineering.

Linearly polarized light absorption spectra of chlorosomes, light-harvesting antennas of photosynthetic green sulfur bacteria

2010 ◽  
Vol 484 (4-6) ◽  
pp. 333-337 ◽  
Author(s):  
Hitoshi Tamiaki ◽  
Shingo Tateishi ◽  
Shosuke Nakabayashi ◽  
Yutaka Shibata ◽  
Shigeru Itoh
Keyword(s):  
Absorption Spectra ◽  
Light Absorption ◽  
Light Harvesting ◽  
Polarized Light ◽  
Green Sulfur Bacteria ◽  
Sulfur Bacteria ◽  
Linearly Polarized ◽  
Green Sulfur

scholarly journals REGIONAL COOPERATION ON THE BLACK SEA: ACHIEVEMENTS, PROBLEMS, PROSPECTS

2013 ◽  
pp. 42-48
Author(s):  
E. D. Eshba
Keyword(s):  
Black Sea ◽  
Large Scale ◽  
Regional Cooperation ◽  
Regional Security ◽  
The Black Sea ◽  
Successful Implementation ◽  
Black Sea Region ◽  
Black Sea Coast ◽  
World Economic ◽  
Transportation Routes

Throughout the history The Black Sea region attracted attention of both regional states and those lying far beyond its borders . One of the main reasons for increased attention to the Black Sea coast is its transit location : it is crossed by transport routes connecting the West with the states of Central Asia and Transcaucasia that are rich by hydrocarbon resources . A large-scale and fairly ambitious gas pipeline projects that are scheduled to take place on the territory of the Black Sea countries and across the Black Sea lead us to expect the increasing role of the Black Sea region in the world economic system. In this regard, the author brings to light the problem of the main stages of the development of cooperation among the Black Sea countries be means of analysis of the most successful attempts at regional cooperation. Special attention is paid to the policy of Turkey in the Black Sea and on the interactions of two major regional actors (Russia and Turkey) . In addition, the work highlights the most promising areas of transport, logistics , trade and economic development of the region , including the project of ring highway around the Black Sea, as well as prospects for the intensification of maritime transport and the development of new marine transportation routes. To summarize, the author concludes that , despite the development of cooperation in the region , there are problems in the formation of a comprehensive system of regional security and cooperation, so as major obstacles to the successful implementation of the plan of cooperation in the Black Sea region still remain .

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