scholarly journals Census of the Viral Metagenome within an Activated Sludge Microbial Assemblage

2010 ◽  
Vol 76 (8) ◽  
pp. 2673-2677 ◽  
Author(s):  
Larissa C. Parsley ◽  
Erin J. Consuegra ◽  
Stephen J. Thomas ◽  
Jaysheel Bhavsar ◽  
Andrew M. Land ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
16S Rrna ◽  
Activated Sludge ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Bacterial Isolates ◽  
Microbial Assemblage ◽  
Culture Independent ◽  
Culture Dependent

ABSTRACT The viral metagenome within an activated sludge microbial assemblage was sampled using culture-dependent and culture-independent methods and compared to the diversity of activated sludge bacterial taxa. A total of 70 unique cultured bacterial isolates, 24 cultured bacteriophages, 829 bacterial metagenomic clones of 16S rRNA genes, and 1,161 viral metagenomic clones were subjected to a phylogenetic analysis.

scholarly journals Coaggregation among Nonflocculating Bacteria Isolated from Activated Sludge

2003 ◽  
Vol 69 (10) ◽  
pp. 6056-6063 ◽  
Author(s):  
Anushree Malik ◽  
Masashi Sakamoto ◽  
Shohei Hanazaki ◽  
Masamitsu Osawa ◽  
Takanori Suzuki ◽  
...  
Keyword(s):  
16S Rrna ◽  
Activated Sludge ◽  
Aggregate Size ◽  
Spectrophotometric Assay ◽  
Full Length ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Acinetobacter Junii ◽  
Acinetobacter Johnsonii

ABSTRACT Thirty-two strains of nonflocculating bacteria isolated from sewage-activated sludge were tested by a spectrophotometric assay for their ability to coaggregate with one other in two-membered systems. Among these strains, eight showed significant (74 to 99%) coaggregation with Acinetobacter johnsonii S35 while only four strains coaggregated, to a lesser extent (43 to 65%), with Acinetobacter junii S33. The extent and pattern of coaggregation as well as the aggregate size showed good correlation with cellular characteristics of the coaggregating partners. These strains were identified by sequencing of full-length 16S rRNA genes. A. johnsonii S35 could coaggregate with strains of several genera, such as Oligotropha carboxidovorans, Microbacterium esteraromaticum, and Xanthomonas spp. The role of Acinetobacter isolates as bridging organisms in multigeneric coaggregates is indicated. This investigation revealed the role of much-neglected nonflocculating bacteria in floc formation in activated sludge.

Amplification of 16S rRNA genes of Anaplasma species in China for phylogenetic analysis

2005 ◽  
Vol 107 (1-2) ◽  
pp. 145-148 ◽  
Author(s):  
Zhijie Liu ◽  
Jianxun Luo ◽  
Qi Bai ◽  
Miling Ma ◽  
Guiguan Guan ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
16S Rrna ◽  
16S Rrna Genes ◽  
Rrna Genes

scholarly journals Responses of Active Ammonia Oxidizers and Nitrification Activity in Eutrophic Lake Sediments to Nitrogen and Temperature

2019 ◽  
Vol 85 (18) ◽  
Author(s):  
Ling Wu ◽  
Cheng Han ◽  
Guangwei Zhu ◽  
Wenhui Zhong
Keyword(s):  
Phylogenetic Analysis ◽  
16S Rrna ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Ammonia Oxidizing Bacteria ◽  
Ammonia Oxidizers ◽  
Nitrogen Input ◽  
Nitrification Activity ◽  
Ammonia Oxidizing Archaea ◽  
Nitrogen Inputs

ABSTRACTAmmonium concentrations and temperature drive the activities of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB), but their effects on these microbes in eutrophic freshwater sediments are unclear. In this study, surface sediments collected from areas of Taihu Lake (China) with different degrees of eutrophication were incubated under three levels of nitrogen input and temperature, and the autotrophic growth of ammonia oxidizers was assessed using13C-labeled DNA-based stable-isotope probing (SIP), while communities were characterized using MiSeq sequencing and phylogenetic analysis of 16S rRNA genes. Nitrification rates in sediment microcosms were positively correlated with nitrogen inputs, but there was no marked association with temperature. Incubation of SIP microcosms indicated that AOA and AOBamoAgenes were labeled by13C at 20°C and 30°C in the slightly eutrophic sediment, and AOBamoAgenes were labeled to a much greater extent than AOAamoAgenes in the moderately eutrophic sediment after 56 days. Phylogenetic analysis of13C-labeled 16S rRNA genes revealed that the active AOA were mainly affiliated with theNitrosopumiluscluster, with theNitrososphaeracluster dominating in the slightly eutrophic sediment at 30°C with low ammonium input (1 mM). Active AOB communities were more sensitive to nitrogen input and temperature than were AOA communities, and they were exclusively dominated by theNitrosomonascluster, which tended to be associated withNitrosomonadaceae-like lineages.Nitrosomonassp. strain Is79A3 tended to dominate the moderately eutrophic sediment at 10°C with greater ammonium input (2.86 mM). The relative abundance responses of the major active communities to nitrogen input and temperature gradients varied, indicating niche differentiation and differences in the physiological metabolism of ammonia oxidizers that are yet to be described.IMPORTANCEBoth archaea and bacteria contribute to ammonia oxidation, which plays a central role in the global cycling of nitrogen and is important for reducing eutrophication in freshwater environments. The abundance and activities of ammonia-oxidizing archaea and bacteria in eutrophic limnic sediments vary with different ammonium concentrations or with seasonal shifts, and how the two factors affect nitrification activity, microbial roles, and active groups in different eutrophic sediments is unclear. The significance of our research is in identifying the archaeal and bacterial responses to anthropogenic activity and climate change, which will greatly enhance our understanding of the physiological metabolic differences of ammonia oxidizers.

Phylogenetic analysis of several Thermus strains from Rehai of Tengchong, Yunnan, China

2005 ◽  
Vol 51 (10) ◽  
pp. 881-886 ◽  
Author(s):  
Lianbing Lin ◽  
Jie Zhang ◽  
Yunlin Wei ◽  
Chaoyin Chen ◽  
Qian Peng
Keyword(s):  
Phylogenetic Analysis ◽  
Secondary Structure ◽  
16S Rrna ◽  
Hot Springs ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Structure Comparison ◽  
Rdna Sequences ◽  
16S Rdna Sequences ◽  
Rehai Geothermal Area

Several Thermus strains were isolated from 10 hot springs of the Rehai geothermal area in Tengchong, Yunnan province. The diversity of Thermus strains was examined by sequencing the 16S rRNA genes and comparing their sequences. Phylogenetic analysis showed that the 16S rDNA sequences from the Rehai geothermal isolates form four branches in the phylogenetic tree and had greater than 95.9% similarity in the phylogroup. Secondary structure comparison also indicated that the 16S rRNA from the Rehai geothermal isolates have unique secondary structure characteristics in helix 6, helix 9, and helix 10 (reference to Escherichia coli). This research is the first attempt to reveal the diversity of Thermus strains that are distributed in the Rehai geothermal area.Key words: Thermus, diversity, phylogenetic analysis, RNA secondary structure.

Polynucleotide Probes That Target a Hypervariable Region of 16S rRNA Genes To Identify Bacterial Isolates Corresponding to Bands of Community Fingerprints

1999 ◽  
Vol 65 (3) ◽  
pp. 1045-1049 ◽  
Author(s):  
Holger Heuer ◽  
Kathrin Hartung ◽  
Gabriele Wieland ◽  
Ina Kramer ◽  
Kornelia Smalla
Keyword(s):  
16S Rrna ◽  
16S Rdna ◽  
Hypervariable Region ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Bacterial Isolates ◽  
Closely Related Species ◽  
Gradient Gel Electrophoresis ◽  
Exonuclease Digestion ◽  
Temperature Gradient Gel Electrophoresis

ABSTRACT Temperature gradient gel electrophoresis (TGGE) is well suited for fingerprinting bacterial communities by separating PCR-amplified fragments of 16S rRNA genes (16S ribosomal DNA [rDNA]). A strategy was developed and was generally applicable for linking 16S rDNA from community fingerprints to pure culture isolates from the same habitat. For this, digoxigenin-labeled polynucleotide probes were generated by PCR, using bands excised from TGGE community fingerprints as a template, and applied in hybridizations with dot blotted 16S rDNA amplified from bacterial isolates. Within 16S rDNA, the hypervariable V6 region, corresponding to positions 984 to 1047 (Escherichia coli 16S rDNA sequence), which is a subset of the region used for TGGE (positions 968 to 1401), best met the criteria of high phylogenetic variability, required for sufficient probe specificity, and closely flanking conserved priming sites for amplification. Removal of flanking conserved bases was necessary to enable the differentiation of closely related species. This was achieved by 5′ exonuclease digestion, terminated by phosphorothioate bonds which were synthesized into the primers. The remaining complementary strand was removed by single-strand-specific digestion. Standard hybridization with truncated probes allowed differentiation of bacteria which differed by only two bases within the probe target site and 1.2% within the complete 16S rDNA. However, a truncated probe, derived from an excised TGGE band of a rhizosphere community, hybridized with three phylogenetically related isolates with identical V6 sequences. Only one of the isolates comigrated with the excised band in TGGE, which was shown to be due to identical sequences, demonstrating the utility of a combined TGGE and V6 probe approach.

Polyphasic analysis for elucidating the taxonomic position of selected unicellular marine cyanobacteria from Indian and Hong Kong coast

Phytotaxa ◽  
2017 ◽  
Vol 307 (4) ◽  
pp. 263
Author(s):  
T. BHUVANESHWARI ◽  
M. SHYLAJANACIYAR ◽  
P. ARUL PRAKASAM ◽  
K. EZHILMARAN ◽  
L. KARTHICK ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
16S Rrna ◽  
Evolutionary Relationship ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Valuable Insight ◽  
Internal Transcribed Spacer Region ◽  
Ultrastructural Studies ◽  
Marine Habitats

Cyanobacteria, the primordial oxygenic photosynthetic prokaryotes encompass a wide spectrum of morphologies and ecologies. The diversity of twelve marine unicellular cyanobacteria isolated from different marine habitats was analyzed morphologically. The evolutionary relationship among the investigated strains was examined by phylogenetic analysis of nearly complete 16S rRNA gene and 16-23S internal transcribed spacer region. Phylogenetic analysis of both 16S rRNA genes and internal spacer regions exhibited coherent clustering patterns. The genetic relatedness of the investigated strains was largely congruent with morphology-based taxonomic groupings. All the investigated strains possess both the types of tRNA (tRNAIle and tRNAAla) in their 16-23S internal spacer regions and significantly varied GC contents and spacer sequence lengths. Further, ultrastructural studies provide a more valuable insight into the cyanobacterial taxa studied. Our study helps to apply the polyphasic approach (use of morphology, ultra-structure, ecology, and molecular analysis of complete 16S rRNA genes and 16-23S internal spacer regions) to resolve taxonomic ambiguities and provide a fairly robust cyanobacterial classification system among the unicellular forms studied.

scholarly journals Monitoring Bacterial Communities in Raw Milk and Cheese by Culture-Dependent and -Independent 16S rRNA Gene-Based Analyses

2007 ◽  
Vol 73 (6) ◽  
pp. 1882-1891 ◽  
Author(s):  
Céline Delbès ◽  
Leila Ali-Mandjee ◽  
Marie-Christine Montel
Keyword(s):  
16S Rrna ◽  
Culture Media ◽  
Raw Milk ◽  
Single Strand Conformation Polymorphism ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Plate Count ◽  
Rrna Gene ◽  
Dual Culture ◽  
Culture Dependent

ABSTRACT The diversity and dynamics of bacterial populations in Saint-Nectaire, a raw-milk, semihard cheese, were investigated using a dual culture-dependent and direct molecular approach combining single-strand conformation polymorphism (SSCP) fingerprinting and sequencing of 16S rRNA genes. The dominant clones, among 125 16S rRNA genes isolated from milk, belonged to members of the Firmicutes (58% of the total clones) affiliated mainly with the orders Clostridiales and the Lactobacillales, followed by the phyla Proteobacteria (21.6%), Actinobacteria (16.8%), and Bacteroidetes (4%). Sequencing the 16S rRNA genes of 126 milk isolates collected from four culture media revealed the presence of 36 different species showing a wider diversity in the Gammaproteobacteria phylum and Staphylococcus genus than that found among clones. In cheese, a total of 21 species were obtained from 170 isolates, with dominant species belonging to the Lactobacillales and subdominant species affiliated with the Actinobacteria, Bacteroidetes (Chryseobacterium sp.), or Gammaproteobacteria (Stenotrophomonas sp.). Fingerprinting DNA isolated from milk by SSCP analysis yielded complex patterns, whereas analyzing DNA isolated from cheese resulted in patterns composed of a single peak which corresponded to that of lactic acid bacteria. SSCP fingerprinting of mixtures of all colonies harvested from plate count agar supplemented with crystal violet and vancomycin showed good potential for monitoring the subdominant Proteobacteria and Bacteroidetes (Flavobacteria) organisms in milk and cheese. Likewise, analyzing culturable subcommunities from cheese-ripening bacterial medium permitted assessment of the diversity of halotolerant Actinobacteria and Staphylococcus organisms. Direct and culture-dependent approaches produced complementary information, thus generating a more accurate view of milk and cheese microbial ecology.

scholarly journals Increase in Terminal Restriction Fragments of Bacteroidetes-Derived 16S rRNA Genes after Administration of Short-Chain Fructooligosaccharides

2006 ◽  
Vol 72 (9) ◽  
pp. 6271-6276 ◽  
Author(s):  
Yusuke Nakanishi ◽  
Koichiro Murashima ◽  
Hiroki Ohara ◽  
Takahisa Suzuki ◽  
Hidenori Hayashi ◽  
...  
Keyword(s):  
16S Rrna ◽  
Intestinal Microbiota ◽  
Fragment Length Polymorphism ◽  
Rflp Analysis ◽  
Intestinal Bacteria ◽  
Short Chain ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Restriction Fragments ◽  
Culture Independent

ABSTRACT It is well known that short chain fructooligosaccharides (scFOS) modify intestinal microbiota in animals as well as in humans. Since most murine intestinal bacteria are still uncultured, it is difficult for a culturing method to detect changes in intestinal microbiota after scFOS administration in a mouse model. In this study, we sought markers of positive change in murine intestinal microbiota after scFOS administration using terminal restriction fragment length polymorphism (T-RFLP) analysis, which is a culture-independent method. The T-RFLP profiles showed that six terminal restriction fragments (T-RFs) were significantly increased after scFOS administration. Phylogenetic analysis of the 16S rRNA partial gene sequences of murine fecal bacteria suggested that four of six T-RFs that increased after scFOS administration were derived from the 16S rRNA genes of the class Bacteroidetes. Preliminary quantification of Bacteroidetes by real-time PCR suggests that the 16S rRNA genes derived from Bacteroidetes were increased by scFOS administration. Therefore, the T-RFs derived from Bacteroidetes are good markers of change of murine intestinal microbiota after scFOS administration.

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