scholarly journals Molecular Characterization of the Nonphotosynthetic Partner Bacterium in the Consortium “Chlorochromatium aggregatum”

2005 ◽  
Vol 71 (11) ◽  
pp. 7434-7441 ◽  
Author(s):  
Birgit E. M. Kanzler ◽  
Kristina R. Pfannes ◽  
Kajetan Vogl ◽  
Jörg Overmann

ABSTRACT Phototrophic consortia represent valuable model systems for the study of signal transduction and coevolution between different bacteria. The phototrophic consortium “Chlorochromatium aggregatum” consists of a colorless central rod-shaped bacterium surrounded by about 20 green-pigmented epibionts. Although the epibiont was identified as a member of the green sulfur bacteria, and recently isolated and characterized in pure culture, the central colorless bacterium has been identified as a member of the β-Proteobacteria but so far could not be characterized further. In the present study, “C. aggregatum” was enriched chemotactically, and the 16S rRNA gene sequence of the central bacterium was elucidated. Based on the sequence information, fluorescence in situ hybridization probes targeting four different regions of the 16S rRNA were designed and shown to hybridize exclusively to cells of the central bacterium. Phylogenetic analyses of the 1,437-bp-long sequence revealed that the central bacterium of “C. aggregatum” represents a so far isolated phylogenetic lineage related to Rhodoferax spp., Polaromonas vacuolata, and Variovorax paradoxus within the family Comamonadaceae. The majority of relatives of this lineage are not yet cultured and were found in low-temperature aquatic environments or aquatic environments containing xenobiotica or hydrocarbons. In CsCl-bisbenzimidazole equilibrium density gradients, genomic DNA of the central bacterium of “Chlorochromatium aggregatum” formed a distinct band which could be detected by quantitative PCR using specific primers. Using this method, the G+C content of the central bacterium was determined to be 55.6 mol%.

2007 ◽  
Vol 74 (3) ◽  
pp. 624-632 ◽  
Author(s):  
Ann K. Manske ◽  
Uta Henßge ◽  
Jens Glaeser ◽  
Jörg Overmann

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.


2004 ◽  
Vol 70 (8) ◽  
pp. 4821-4830 ◽  
Author(s):  
Jens Glaeser ◽  
Jörg Overmann

ABSTRACT Motile phototrophic consortia are highly regular associations in which numerous cells of green sulfur bacteria surround a flagellated colorless β-proteobacterium in the center. To date, seven different morphological types of such consortia have been described. In addition, two immotile associations involving green sulfur bacteria are known. By employing a culture-independent approach, different types of phototrophic consortia were mechanically isolated by micromanipulation from 14 freshwater environments, and partial 16S rRNA gene sequences of the green sulfur bacterial epibionts were determined. In the majority of the lakes investigated, different types of phototrophic consortia were found to co-occur. In all cases, phototrophic consortia with the same morphology from the same habitat contained only a single epibiont phylotype. However, morphologically indistinguishable phototrophic consortia collected from different lakes contained different epibionts. Overall, 19 different types of epibionts were detected in the present study. Whereas the epibionts within one geographic region were very similar (Dice coefficient, 0.582), only two types of epibionts were found to occur on both the European and North American continents (Dice coefficient, 0.190). None of the epibiont 16S rRNA gene sequences have been detected so far in free-living green sulfur bacteria, suggesting that the interaction between epibionts and chemotrophic bacteria in the phototrophic consortia is an obligate interaction. Based on our phylogenetic analysis, the epibiont sequences are not monophyletic. Thus, the ability to form symbiotic associations either arose independently from different ancestors or was present in a common ancestor prior to the radiation of green sulfur bacteria and the transition to the free-living state in independent lineages. The present study thus demonstrates that there is great diversity and nonrandom geographical distribution of phototrophic consortia in the natural environment.


2003 ◽  
Vol 69 (7) ◽  
pp. 3739-3750 ◽  
Author(s):  
Jens Glaeser ◽  
Jörg Overmann

ABSTRACT A dense population of the phototrophic consortium “Pelochromatium roseum” was investigated in the chemocline of a temperate holomictic lake (Lake Dagow, Brandenburg, Germany). Fluorescence in situ hybridization revealed that the brown epibionts of “P. roseum” constituted up to 37% of the total bacterial cell number and up to 88% of all green sulfur bacteria present in the chemocline. Specific amplification of 16S rRNA gene fragments of green sulfur bacteria and denaturing gradient gel electrophoresis fingerprinting yielded a maximum of four different DNA bands depending on the year of study, indicating that the diversity of green sulfur bacteria was low. The 465-bp 16S rRNA gene sequence of the epibiont of “P. roseum” was obtained after sorting of individual consortia by micromanipulation, followed by a highly sensitive PCR. The sequence obtained represents a new phylotype within the radiation of green sulfur bacteria. Maximum light-dependent H14CO3 − fixation in the chemocline in the presence of 3-(3,4-dichlorophenyl)-1,1-dimethylurea suggested that there was anaerobic autotrophic growth of the green sulfur bacteria. The metabolism of the epibionts was further studied by determining stable carbon isotope ratios (δ13C) of their specific biomarkers. Analysis of photosynthetic pigments by high-performance liquid chromatography revealed the presence of high concentrations of bacteriochlorophyll (BChl) e and smaller amounts of BChl a and d and chlorophyll a in the chemocline. Unexpectedly, isorenieratene and β-isorenieratene, carotenoids typical of other brown members of the green sulfur bacteria, were absent. Instead, four different esterifying alcohols of BChl e were isolated as biomarkers of green sulfur bacterial epibionts, and their δ13C values were determined. Farnesol, tetradecanol, hexadecanol, and hexadecenol all were significantly enriched in 13C compared to bulk dissolved and particulate organic carbon and compared to the biomarkers of purple sulfur bacteria. The difference between the δ13C values of farnesol, the major esterifying alcohol of BChl e, and CO2 was −7.1%, which provides clear evidence that the mode of growth of the green sulfur bacterial epibionts of “P. roseum” in situ is photoautotrophic.


2005 ◽  
Vol 55 (3) ◽  
pp. 1167-1170 ◽  
Author(s):  
Jung-Hoon Yoon ◽  
Kook Hee Kang ◽  
Soo-Hwan Yeo ◽  
Tae-Kwang Oh

A Gram-negative, non-spore-forming, yellow-pigmented, slightly halophilic bacterial strain, SW-109T, was isolated from a tidal flat of the Yellow Sea in Korea, and subjected to a polyphasic taxonomic study. This isolate did not produce bacteriochlorophyll a and contained ubiquinone-10 as the predominant respiratory lipoquinone and C18 : 1 ω7c as the major fatty acid. The DNA G+C content was 60·3 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain SW-109T is phylogenetically affiliated to the genus Erythrobacter of the family Sphingomonadaceae. Strain SW-109T exhibited levels of 16S rRNA gene sequence similarity to the type strains of Erythrobacter species of 94·0–96·3 %, making it possible to categorize strain SW-109T as a species that is separate from previously recognized Erythrobacter species. On the basis of its phenotypic properties and phylogenetic distinctiveness, SW-109T (=KCTC 12311T=JCM 12599T) was classified as the type strain of a novel Erythrobacter species, for which the name Erythrobacter luteolus sp. nov. is proposed.


2012 ◽  
Vol 62 (Pt_9) ◽  
pp. 2163-2168 ◽  
Author(s):  
Yong-Taek Jung ◽  
Ji-Hoon Kim ◽  
So-Jung Kang ◽  
Tae-Kwang Oh ◽  
Jung-Hoon Yoon

A Gram-staining-negative, non-flagellated, non-gliding and pleomorphic bacterial strain, designated DPG-25T, was isolated from seawater in a seaweed farm in the South Sea in Korea and its taxonomic position was investigated by using a polyphasic approach. Strain DPG-25T grew optimally at 25 °C, at pH 7.0–7.5 and in the presence of 2 % (w/v) NaCl. Flexirubin-type pigments were not produced. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain DPG-25T formed a cluster with the type strains of Actibacter sediminis , Aestuariicola saemankumensis and Lutimonas vermicola . Strain DPG-25T exhibited 16S rRNA gene sequence similarity values of 95.3, 93.1 and 93.6 % to the type strains of Actibacter sediminis , Aestuariicola saemankumensis and L. vermicola , respectively. Strain DPG-25T contained MK-6 as the predominant menaquinone and iso-C15 : 0 and iso-C17 : 0 3-OH as the major fatty acids. The major polar lipids detected in strain DPG-25T were phosphatidylethanolamine and one unidentified lipid. The DNA G+C content was 39.9 mol%. Differential phenotypic properties and the phylogenetic distinctiveness of strain DPG-25T demonstrated that this strain is distinguishable from Actibacter sediminis , Aestuariicola saemankumensis and L. vermicola . On the basis of the data presented here, strain DPG-25T represents a novel species in a novel genus of the family Flavobacteriaceae , for which the name Namhaeicola litoreus gen. nov., sp. nov. is proposed. The type strain of Namhaeicola litoreus is DPG-25T ( = KCTC 23702T  = CCUG 61485T).


2015 ◽  
Vol 65 (Pt_4) ◽  
pp. 1207-1212 ◽  
Author(s):  
Hong-Fei Wang ◽  
Yong-Guang Zhang ◽  
Ji-Yue Chen ◽  
Jian-Wei Guo ◽  
Li Li ◽  
...  

A novel endophytic actinobacterium, designated EGI 6500707T, was isolated from the surface-sterilized root of a halophyte Anabasis elatior (C. A. Mey.) Schischk collected from Urumqi, Xinjiang province, north-west China, and characterized using a polyphasic approach. Cells were Gram-stain-positive, non-motile, short rods and produced white colonies. Growth occurred at 10–45 °C (optimum 25–30 °C), at pH 5–10 (optimum pH 8) and in presence of 0–4 % (w/v) NaCl (optimum 0–3 %). The predominant menaquinone was MK-9. The diagnostic phospholipids were diphosphatidylglycerol and phosphatidylglycerol. The major fatty acids were anteiso-C15 : 0, anteiso-C17 : 0 and iso-C16 : 0. The DNA G+C content of strain EGI 6500707T was 69.1 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain EGI 6500707T should be placed in the genus Frigoribacterium (family Microbacteriaceae , phylum Actinobacteria ), and that the novel strain exhibited the highest 16S rRNA gene sequence similarity to Frigoribacterium faeni JCM 11265T (99.1 %) and Frigoribacterium mesophilum MSL-08T (96.5 %). DNA–DNA relatedness between strain EGI 6500707T and F. faeni JCM 11265T was 47.2 %. On the basis of phenotypic and chemotaxonomic characteristics, phylogenetic analysis and DNA–DNA relatedness data, strain EGI 6500707T represents a novel species of the genus Frigoribacterium , for which the name Frigoribacterium endophyticum sp. nov. is proposed. The type strain is EGI 6500707T ( = JCM 30093T = KCTC 29493T).


Author(s):  
Kiran Kirdat ◽  
Bhavesh Tiwarekar ◽  
Vipool Thorat ◽  
Shivaji Sathe ◽  
Yogesh Shouche ◽  
...  

Sugarcane Grassy Shoot (SCGS) disease is known to be related to Rice Yellow Dwarf (RYD) phytoplasmas (16SrXI-B group) which are found predominantly in sugarcane growing areas of the Indian subcontinent and South-East Asia. The 16S rRNA gene sequences of SCGS phytoplasma strains belonging to the 16SrXI-B group share 98.07 % similarity with ‘Ca. Phytoplasma cynodontis’ strain BGWL-C1 followed by 97.65 % similarity with ‘Ca. P. oryzae’ strain RYD-J. Being placed distinctly away from both the phylogenetically related species, the taxonomic identity of SCGS phytoplasma is unclear and confusing. We attempted to resolve the phylogenetic positions of SCGS phytoplasma based on the phylogenetic analysis of 16S rRNA gene (>1500 bp), nine housekeeping genes (>3500 aa), core genome phylogeny (>10 000 aa) and OGRI values. The draft genome sequences of SCGS phytoplasma (strain SCGS) and Bermuda Grass White leaf (BGWL) phytoplasma (strain LW01), closely related to ‘Ca. P. cynodontis’, were obtained. The SCGS genome was comprised of 29 scaffolds corresponding to 505 173 bp while LW01 assembly contained 21 scaffolds corresponding to 483 935 bp with the fold coverages over 330× and completeness over 90 % for both the genomes. The G+C content of SCGS was 19.86 % while that of LW01 was 20.46 %. The orthoANI values for the strain SCGS against strains LW01 was 79.42 %, and dDDH values were 22. Overall analysis reveals that SCGS phytoplasma forms a distant clade in RYD group of phytoplasmas. Based on phylogenetic analyses and OGRI values obtained from the genome sequences, a novel taxon ‘Candidatus Phytoplasma sacchari’ is proposed.


2015 ◽  
Vol 65 (Pt_7) ◽  
pp. 2320-2325 ◽  
Author(s):  
Shih-Yao Lin ◽  
Asif Hameed ◽  
Cheng-Zhe Wen ◽  
You-Cheng Liu ◽  
Yi-Han Hsu ◽  
...  

A Gram-stain-negative, aerobic, rod-shaped, yellow-pigment-producing bacterium (designated strain CC-CZW007T) was isolated from seafood samples (sea urchins) at Penghu Island in Taiwan. Strain CC-CZW007T grew optimally at pH 7.0 and 30 °C in the presence of 3 % (w/v) NaCl. The novel strain shared highest 16S rRNA gene sequence similarity to Vitellibacter vladivostokensis JCM 11732T (96.8 %), Vitellibacter soesokkakensis KCTC 32536T (96.4 %), Vitellibacter nionensis KCTC 32420T (95.8 %) and Vitellibacter aestuarii JCM 15496T (95.6 %) and lower sequence similarity to members of other genera. Phylogenetic analyses based on 16S rRNA genes revealed a distinct taxonomic position attained by strain CC-CZW007T with respect to other species of the genus Vitellibacter. The major fatty acids were iso-C15 : 0 and iso-C17 : 0 3-OH. The polar lipid profile was composed of major amounts of phosphatidylethanolamine, unidentified lipids and aminolipids; a moderate amount of aminophospholipid was also detected. The DNA G+C content was 34.7 mol%. The predominant quinone system was menaquinone (MK-6). On the basis of polyphasic taxonomic evidence presented here, strain CC-CZW007T is proposed to represent a novel species within the genus Vitellibacter, for which the name Vitellibacter echinoideorum sp. nov. is proposed. The type strain is CC-CZW007T ( = BCRC 80886T = JCM 30378T).


Author(s):  
Peng Wang ◽  
Yuxin Gao

Chakrabartia godavariana PRB40T was compared with Aestuariisphingobium litorale SYSU M10002T to examine the taxonomic relationship between the two type strains. The 16S rRNA gene sequence of C. godavariana PRB40T had high similarity (99.8 %) to that of A. litorale SYSU M10002T. The results of phylogenetic analyses based on 16S rRNA gene sequences indicated that the two strains formed a tight cluster within the genus Chakrabartia . A draft genomic comparison between the two strains revealed an average nucleotide identity of 97.3 % and a digital DNA–DNA hybridization estimate of 79.5±2.9 %, strongly indicating that the two strains represented a single species. In addition, neither strain displayed any striking differences in metabolic, physiological or chemotaxonomic features. Therefore, we propose that Aestuariisphingobium litorale is a later heterotypic synonym of Chakrabartia godavariana .


Author(s):  
Xiao-Xian Huang ◽  
Jia Shang ◽  
Lian Xu ◽  
Rui Yang ◽  
Ji-Quan Sun

A Gram-stain-negative, non-motile, rod-shaped bacterial strain, named SJ-16T, was isolated from desert soil collected in Inner Mongolia, northern PR China. Strain SJ-16T grew at pH 6.0–11.0 (optimum, pH 8.0–9.0), 4–40 °C (optimum, 30–35 °C) and in the presence of 0–8 % (w/v) NaCl (optimum, 0–2 %). The strain was negative for catalase and positive for oxidase. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain SJ-16T clustered with Luteimonas chenhongjianii 100111T and Luteimonas terrae THG-MD21T, and had 98.8, 98.6, 98.3 and <97.9 % of 16S rRNA gene sequence similarity to strains L. chenhongjianii 100111T, L. terrae THG-MD21T, L. aestuarii B9T and all other type strains of the genus Luteimonas , respectively. The major cellular fatty acids were iso-C15 : 0, iso-C16 : 0, summed feature 3 (C16 : 1  ω7c and/or C16 : 1  ω6c) and summed feature 9 (C16 : 0 10-methyl and/or iso-C17 : 1  ω9c). Diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine were the major polar lipids, and ubiquinone-8 was the only respiratory quinone. The genomic DNA G+C content was 69.3 mol%. The digital DNA–DNA hybridization and average nucleotide identity values of strain SJ-16T to L. chenhongjianii 100111T, L. terrae THG-MD21T, L. rhizosphaerae 4-12T and L. aestuarii B9T were 36.9, 37.5, 24.0 and 21.1 %, and 80.9, 80.6, 80.7 and 76.3 %, respectively. Based on phenotypic, physiological and phylogenetic results, strain SJ-16T represents a novel species of the genus Luteimonas , for which the name Luteimonas deserti is proposed. The type strain is SJ-16T (=CGMCC 1.17694T=KCTC 82207T).


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