Molecular community analysis of magnesium-rich bittern brine recovered from a Tunisian solar saltern

2011 ◽  
Vol 57 (12) ◽  
pp. 975-981 ◽  
Author(s):  
Houda Baati ◽  
Raja Jarboui ◽  
Néji Gharsallah ◽  
Abdelghani Sghir ◽  
Emna Ammar
Keyword(s):  
16S Rrna ◽  
Sequence Similarity ◽  
Archaeal Community ◽  
Community Analysis ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Solar Saltern ◽  
16S Rrna Gene Analysis ◽  
Operational Taxonomic Units

The microbial community of a magnesium-rich bittern brine saturated with NaCl (380–400 g/L) from a Tunisian solar saltern was investigated using a molecular approach based on 16S rRNA gene analysis and viability tests. The results revealed the existence of microbial flora. Viability test assessment showed that 46.4% of this flora was viable but not detectable by culturability tests. 16S rRNA genes from 49 bacterial clones and 38 archaeal clones were sequenced and phylogenetically analyzed. Eleven operational taxonomic units (OTUs) determined by the DOTUR program with 97% sequence similarity were generated for Bacteria. These OTUs were affiliated with Bacteroidetes and Gammaproteobacteria. The archaeal community composition exhibited more diversity with 38 clones, resulting in 13 OTUs affiliated with the Euryarchaeota phylum. Diversity measurement showed a more diverse archaeal than bacterial community at the saturated pond.

Quantitatively evaluating mistaken clone assignments by RFLP analysis of 16S rRNA genes: a case study

2008 ◽  
Vol 54 (6) ◽  
pp. 479-482 ◽  
Author(s):  
Han-Bo Zhang ◽  
Chan-Wen Xu ◽  
Miao-Miao Wang ◽  
Tao Li ◽  
Zhi-Wei Zhao
Keyword(s):  
16S Rrna ◽  
Sequence Similarity ◽  
Rflp Analysis ◽  
Restriction Enzymes ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Taxonomic Rank ◽  
Operational Taxonomic Units

We quantitatively evaluated the errors of clone assignment based on the restriction fragment length polymorphism (RFLP) pattern of 16S rRNA genes. Eighty clones were randomly selected from a 16S rRNA gene library and were categorized into 35 operational taxonomic units (OTU) based on their indistinguishable enzyme restriction patterns of 3 tetrameric restriction enzymes RsaI, BsuRI, and HinfI. All of these clones were then sequenced and were reassigned into 36–53 OTUs using the DOTUR program when sequence similarities of 95%–100% were used. The number of the identically assigned clones ranged from 53 to 61 and the percentage varied from 66.3% to 76.3%. The Shannon–Weaver index for the bacterial community observed by RFLP analysis was 2.75, equal to that estimated by DOTUR at a 97% sequence similarity. Compared with clones assigned with the DOTUR program at a 97% sequence similarity, only 61 clones (76.3%) were correctly assigned by RFLP analysis. Six clones (7.5%) were assigned mistakenly at the phylum level, and the positions of 13 clones (16.2%) were phylogenetically different at a lower taxonomic rank.

scholarly journals Opening a next-generation black box: ecological trends for hundreds of species-like taxa uncovered within a single bacterial >99% 16S rRNA operational taxonomic unit

2021 ◽  
Author(s):  
Martin Hahn ◽  
Andrea Huemer ◽  
Alexandra Pitt ◽  
Matthias Hoetzinger
Keyword(s):  
16S Rrna ◽  
Sequence Similarity ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Taxon Richness ◽  
Large Set ◽  
Free Living ◽  
Environmental Distribution ◽  
Living Bacteria

Current knowledge on environmental distribution and taxon richness of free-living bacteria is mainly based on cultivation-independent investigations employing 16S rRNA gene sequencing methods. Yet, 16S rRNA genes are evolutionarily rather conserved, resulting in limited taxonomic and ecological resolutions provided by this marker. We used a faster evolving protein-encoding marker to reveal ecological patterns hidden within a single OTU defined by >99% 16S rRNA sequence similarity. The studied taxon, subcluster PnecC of the genus Polynucleobacter, represents a ubiquitous group of planktonic freshwater bacteria with cosmopolitan distribution, which is very frequently detected by diversity surveys of freshwater systems. Based on genome taxonomy and a large set of genome sequences, a sequence similarity threshold for delineation of species-like taxa could be established. In total, 600 species-like taxa were detected in 99 freshwater habitats scattered across three regions representing a latitudinal range of 3400 km (42°N to 71°N) and a pH gradient of 4.2 to 8.6. Besides the unexpectedly high richness, the increased taxonomic resolution revealed structuring of Polynucleobacter communities by a couple of macroecological trends, which was previously only demonstrated for phylogenetically much broader groups of bacteria. A unexpected pattern was the almost complete compositional separation of Polynucleobacter communities of Ca-rich and Ca-poor habitats, which strongly resembled the vicariance of plant species on silicate and limestone soils. The presented new cultivation-independent approach opened a window to an incredible, previously unseen diversity, and enables investigations aiming on deeper understanding of how environmental conditions shape bacterial communities and drive evolution of free-living bacteria.

scholarly journals Vitellibacter echinoideorum sp. nov., isolated from a sea urchin (Tripneustes gratilla)

2015 ◽  
Vol 65 (Pt_7) ◽  
pp. 2320-2325 ◽  
Author(s):  
Shih-Yao Lin ◽  
Asif Hameed ◽  
Cheng-Zhe Wen ◽  
You-Cheng Liu ◽  
Yi-Han Hsu ◽  
...  
Keyword(s):  
16S Rrna ◽  
Sea Urchins ◽  
Sequence Similarity ◽  
Phylogenetic Analyses ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Rrna Gene ◽  
The Novel ◽  
Moderate Amount ◽  
Polar Lipid Profile

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).

Thalassobacter stenotrophicus Macián et al. 2005 is a later synonym of Jannaschia cystaugens Adachi et al. 2004, with emended description of the genus Thalassobacter

2005 ◽  
Vol 55 (5) ◽  
pp. 1959-1963 ◽  
Author(s):  
M. J. Pujalte ◽  
M. C. Macián ◽  
D. R. Arahal ◽  
E. Garay
Keyword(s):  
16S Rrna ◽  
Genomic Dna ◽  
Sequence Similarity ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Phenotypic Traits ◽  
Rrna Gene ◽  
Phenotypic Properties ◽  
Sequence Comparisons ◽  
Emended Description

The type strains of Jannaschia cystaugens (LMG 22015T) and Thalassobacter stenotrophicus (CECT 5294T) were analysed by means of genomic DNA–DNA hybridization, comparison of 16S rRNA gene sequences and phenotypic properties determined under the same methodological conditions. J. cystaugens LMG 22015T showed DNA–DNA relatedness levels of 72 % when hybridized with the genomic DNA of T. stenotrophicus CECT 5294T. Sequence comparisons revealed that the 16S rRNA genes of the two strains had a similarity of 99·8 %. The cellular fatty acid and polar lipid compositions of the two strains and their DNA mol% G+C contents were almost identical. Bacteriochlorophyll a (Bchl a) and polyhydroxybutyrate were produced by both strains under the same culture conditions. Their closest phylogenetic neighbours were Jannaschia helgolandensis and Jannaschia rubra; however, the low sequence similarity values (95·7–95·9 %) and several important differences in phenotypic traits (ionic requirements, Bchl a production and polar lipids) support the distinction between the genera Thalassobacter and Jannaschia. Thus, we propose the unification of J. cystaugens (LMG 22015T) and T. stenotrophicus (CECT 5294T) as Thalassobacter stenotrophicus (type strain, CECT 5294T=DSM 16310T). An emended description of the genus Thalassobacter is also presented.

scholarly journals Halopiger xanaduensis gen. nov., sp. nov., an extremely halophilic archaeon isolated from saline Lake Shangmatala in Inner Mongolia, China

2007 ◽  
Vol 57 (7) ◽  
pp. 1402-1407 ◽  
Author(s):  
M. C. Gutiérrez ◽  
A. M. Castillo ◽  
M. Kamekura ◽  
Y. Xue ◽  
Y. Ma ◽  
...  
Keyword(s):  
16S Rrna ◽  
Inner Mongolia ◽  
Saline Lake ◽  
Sequence Similarity ◽  
Optimal Growth ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Rrna Gene ◽  
The Family ◽  
Extremely Halophilic Archaeon

Strain SH-6T was isolated from the sediment of Lake Shangmatala, a saline lake in Inner Mongolia (China). Cells were pleomorphic. The organism was neutrophilic and required at least 2.5 M (15 %) NaCl, but not MgCl2, for growth; optimal growth occurred at 4.3 M (25 %) NaCl. The G+C content of its DNA was 63.1 mol%. 16S rRNA gene sequence analysis revealed that strain SH-6T is a member of the family Halobacteriaceae, but there was a low level of similarity with other members of this family. Highest sequence similarity (94.6 %) was obtained with the 16S rRNA genes of the type strains of Natronolimnobius innermongolicus and Natronolimnobius baerhuensis. Polar lipid analyses revealed that strain SH-6T contains phosphatidylglycerol and phosphatidylglyceromethylphosphate, derived from both C20C20 and C20C25 glycerol diethers together with the glycolipid S2-DGD-1. On the basis of the data obtained, the new isolate could not be classified in any recognized genus. Strain SH-6T is thus considered to represent a novel species in a new genus within the family Halobacteriaceae, order Halobacteriales, for which the name Halopiger xanaduensis gen. nov., sp. nov. is proposed. The type strain of Halopiger xanaduensis is SH-6T (=CECT 7173T=CGMCC 1.6379T=JCM 14033T).

scholarly journals Mucilaginibacter koreensis sp. nov., isolated from leaf mould

2014 ◽  
Vol 64 (Pt_7) ◽  
pp. 2274-2279 ◽  
Author(s):  
Cheol Su Park ◽  
Kyudong Han ◽  
Tae-Young Ahn
Keyword(s):  
16S Rrna ◽  
Type Species ◽  
Sequence Similarity ◽  
Optimal Growth ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Strictly Aerobic ◽  
Content Type ◽  
Link Type

A Gram-staining-negative, strictly aerobic, rod-shaped, pale-pink pigmented bacterial strain, designated TF8T, was isolated from leaf mould in Cheonan, Republic of Korea. Its taxonomic position was determined through a polyphasic approach. Optimal growth occurred on R2A agar without NaCl supplementation, at 25–28 °C and at pH 6.0–7.0. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain TF8T belongs to the genus Mucilaginibacter in the family Sphingobacteriaceae . The sequence similarity between 16S rRNA genes of strain TF8T and the type strains of other species of the genus Mucilaginibacter ranged from 92.1 to 94.7 %. The closest relatives of strain TF8T were Mucilaginibacter lutimaris BR-3T (94.7 %), M. soli R9-65T (94.5 %), M. litoreus BR-18T (94.5 %), M. rigui WPCB133T (94.0 %) and M. daejeonensis Jip 10T (93.8 %). The major isoprenoid quinone was MK-7 and the major cellular fatty acids were iso-C15 : 0 (33.0 %), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c; 24.8 %) and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c; 13.0 %). The major polar lipids of TF8T were phosphatidylethanolamine and three unidentified aminophospholipids. The G+C content of the genomic DNA was 46.2 mol%. On the basis of the data presented here, strain TF8T is considered to represent a novel species of the genus Mucilaginibacter , for which the name Mucilaginibacter koreensis sp. nov. is proposed. The type strain is TF8T ( = KACC 17468T = JCM 19323T).

scholarly journals rDNA analyses of planktonic heterocystous cyanobacteria, including members of the genera Anabaenopsis and Cyanospira The GenBank accession numbers of the 16S rDNA gene sequences reported in this paper are AY038032–AY038037.

Microbiology ◽  
2002 ◽  
Vol 148 (2) ◽  
pp. 481-496 ◽  
Author(s):  
Isabelle Iteman ◽  
Rosmarie Rippka ◽  
Nicole Tandeau de Marsac ◽  
Michael Herdman
Keyword(s):  
16S Rrna ◽  
16S Rdna ◽  
Genomic Sequence ◽  
Sequence Similarity ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
23S Rrna ◽  
Phylogenetic Position ◽  
Rrna Gene ◽  
Heterocystous Cyanobacteria

The taxonomic coherence and phylogenetic relationships of 11 planktonic heterocystous cyanobacterial isolates were examined by investigating two areas of the rRNA operon, the 16S rRNA gene (rrnS) and the internal transcribed spacer (ITS) located between the 16S rRNA and 23S rRNA genes. The rrnS sequences were determined for five strains, including representatives of Anabaena flos-aquae, Aphanizomenon flos-aquae, Nodularia sp. and two alkaliphilic planktonic members of the genera Anabaenopsis and Cyanospira, whose phylogenetic position was previously unknown. Comparison of the data with those previously published for individual groups of planktonic heterocystous cyanobacteria showed that, with the exception of members assigned to the genus Cylindrospermopsis, all the planktonic strains form a distinct subclade within the monophyletic clade of heterocystous cyanobacteria. Within this subclade five different phylogenetic clusters were distinguished. The phylogenetic groupings of Anabaena and Aphanizomenon strains within three of these clusters were not always consistent with their generic or specific assignments based on classical morphological definitions, and the high degree of sequence similarity between strains of Anabaenopsis and Cyanospira suggests that they may be assignable to a single genus. Ribotyping and additional studies performed on PCR amplicons of the 16S rDNA or the ITS for the 11 planktonic heterocystous strains demonstrated that they all contain multiple rrn operons and ITS regions of variable size. Finally, evidence is provided for intra-genomic sequence heterogeneity of the 16S rRNA genes within most of the individual isolates.

scholarly journals Haloferax larsenii sp. nov., an extremely halophilic archaeon from a solar saltern

2007 ◽  
Vol 57 (4) ◽  
pp. 717-720 ◽  
Author(s):  
Xue-Wei Xu ◽  
Yue-Hong Wu ◽  
Chun-Sheng Wang ◽  
Aharon Oren ◽  
Pei-Jin Zhou ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Sequence Similarity ◽  
Halophilic Archaea ◽  
Rrna Gene ◽  
Solar Saltern ◽  
Biochemical Tests ◽  
16S Rrna Gene Analysis ◽  
Extremely Halophilic Archaeon ◽  
Derivatives Of

Three strains of Gram-negative, aerobic, neutrophilic, extremely halophilic archaea, designated ZJ206T, ZJ203 and ZJ204, were isolated from a solar saltern in Zhe-Jiang Province, China. Phenotypically and on the basis of 16S rRNA gene sequences, the strains were very similar. Comparative 16S rRNA gene analysis revealed 96.4–97.4 % sequence similarity to members of the genus Haloferax. The major polar lipids were C20C20 derivatives of phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, diglycosyl glycerol diether and sulfated diglycosyl diether. The DNA G+C content of strain ZJ206T was 62.2 mol%. The results of DNA–DNA hybridizations and physiological and biochemical tests allowed genotypic and phenotypic differentiation of the isolates from closely related species. Therefore the isolates should be classified as members of a novel species, for which the name Haloferax larsenii sp. nov. is proposed. The type strain is ZJ206T (=CGMCC 1.5347T=JCM 13917T).

Microbial community of salt crystals processed from Mediterranean seawater based on 16S rRNA analysis

2010 ◽  
Vol 56 (1) ◽  
pp. 44-51 ◽  
Author(s):  
Houda Baati ◽  
Sonda Guermazi ◽  
Neji Gharsallah ◽  
Abdelghani Sghir ◽  
Emna Ammar
Keyword(s):  
Microbial Community ◽  
16S Rrna ◽  
Sequence Similarity ◽  
Archaeal Community ◽  
Solar Saltern ◽  
16S Rrna Sequence ◽  
16S Rrna Analysis ◽  
Operational Taxonomic Units ◽  
Local Diversity ◽  
Salt Crystals

Phylogenetic analysis of 16S rRNA was used to investigate for the first time the structure of the microbial community that inhabits salt crystals retrieved from the bottom of a solar saltern, located in the coastal area of the Mediterranean Sea (Sfax, Tunisia). This community lives in an extremely salty environment of 250–310 g/L total dissolved salt. A total of 78 bacterial 16S rRNA clone sequences making up to 21 operational taxonomic units (OTUs), determined by the DOTUR program to 97% sequence similarity, was analyzed. These OTUs were affiliated to Bacteroidetes (71.4% of OTUs), and γ-Proteobacteria and α-Proteobacteria (equally represented by 14.2% of the OTUs observed). The archaeal community composition appeared more diverse with 68 clones, resulting in 44 OTUs, all affiliated with the Euryarchaeota phylum. Of the bacterial and archaeal clones showing <97% 16S rRNA sequence identity with sequences in public databases, 47.6% and 84.1% respectively were novel clones. Both rarefaction curves and diversity measurements (Simpson, Shannon–Weaver, Chao) showed a more diverse archaeal than bacterial community at the Tunisian solar saltern pond. The analysis of an increasing clone’s number may reveal additional local diversity.

Natronoarchaeum rubrum sp. nov., isolated from a marine solar saltern, and emended description of the genus Natronoarchaeum

2014 ◽  
Vol 64 (Pt_3) ◽  
pp. 952-956 ◽  
Author(s):  
Xing-Xing Qiu ◽  
Mei-Lin Zhao ◽  
Heng-Lin Cui
Keyword(s):  
16S Rrna ◽  
Type Species ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Solar Saltern ◽  
Marine Solar Saltern ◽  
Content Type ◽  
Link Type ◽  
Emended Description

A halophilic archaeal strain, GX48T, was isolated from the Gangxi marine solar saltern near Weihai city in Shandong Province, China. Cells of the strain were rod-shaped, stained Gram-negative and formed red-pigmented colonies. Strain GX48T was able to grow at 25–50 °C (optimum 37 °C), in the presence of 1.4–4.8 M NaCl (optimum 2.6 M NaCl), with 0–1.0 M MgCl2 (optimum 0.05 M MgCl2) and at pH 5.5–9.5 (optimum pH 7.0). Cells lysed in distilled water and the minimal NaCl concentration to prevent cell lysis was 8 % (w/v). The major polar lipids of the strain were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester and two major glycolipids chromatographically identical to those of Natronoarchaeum mannanilyticum YSM-123T and Natronoarchaeum philippinense 294-194-5T. 16S rRNA gene analysis revealed that strain GX48T had two dissimilar 16S rRNA genes and both of them were phylogenetically related to those of the two current members of the genus Natronoarchaeum (96.2–98.3 % similarities). The rpoB′ gene sequence similarities between strain GX48T and Natronoarchaeum mannanilyticum YSM-123T and Natronoarchaeum philippinense 294-194-5T were 96.0 % and 94.7 %, respectively. The DNA G+C content of strain GX48T was 66.2 mol%. Strain GX48T showed low DNA–DNA relatedness with the two members of the genus Natronoarchaeum . It was concluded that strain GX48T ( = CGMCC 1.10388T = JCM 17119T) represents a novel species of the genus Natronoarchaeum , for which the name Natronoarchaeum rubrum sp. nov. is proposed. An emended description of the genus Natronoarchaeum is also presented.

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