scholarly journals A method for achieving complete microbial genomes and improving bins from metagenomics data

2021 ◽  
Vol 17 (5) ◽  
pp. e1008972
Author(s):  
Lauren M. Lui ◽  
Torben N. Nielsen ◽  
Adam P. Arkin
Keyword(s):  
Ribosomal Rna ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Genomic Context ◽  
Protein Coding ◽  
Viral Genomes ◽  
Automated Method ◽  
A Genome ◽  
Sequencing Studies ◽  
Metagenomics Data

Metagenomics facilitates the study of the genetic information from uncultured microbes and complex microbial communities. Assembling complete genomes from metagenomics data is difficult because most samples have high organismal complexity and strain diversity. Some studies have attempted to extract complete bacterial, archaeal, and viral genomes and often focus on species with circular genomes so they can help confirm completeness with circularity. However, less than 100 circularized bacterial and archaeal genomes have been assembled and published from metagenomics data despite the thousands of datasets that are available. Circularized genomes are important for (1) building a reference collection as scaffolds for future assemblies, (2) providing complete gene content of a genome, (3) confirming little or no contamination of a genome, (4) studying the genomic context and synteny of genes, and (5) linking protein coding genes to ribosomal RNA genes to aid metabolic inference in 16S rRNA gene sequencing studies. We developed a semi-automated method called Jorg to help circularize small bacterial, archaeal, and viral genomes using iterative assembly, binning, and read mapping. In addition, this method exposes potential misassemblies from k-mer based assemblies. We chose species of the Candidate Phyla Radiation (CPR) to focus our initial efforts because they have small genomes and are only known to have one ribosomal RNA operon. In addition to 34 circular CPR genomes, we present one circular Margulisbacteria genome, one circular Chloroflexi genome, and two circular megaphage genomes from 19 public and published datasets. We demonstrate findings that would likely be difficult without circularizing genomes, including that ribosomal genes are likely not operonic in the majority of CPR, and that some CPR harbor diverged forms of RNase P RNA. Code and a tutorial for this method is available at https://github.com/lmlui/Jorg and is available on the DOE Systems Biology KnowledgeBase as a beta app.

scholarly journals A method for achieving complete microbial genomes and improving bins from metagenomics data

2020 ◽  
Author(s):  
Lauren M. Lui ◽  
Torben N. Nielsen ◽  
Adam P. Arkin
Keyword(s):  
Ribosomal Rna ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Genomic Context ◽  
Protein Coding ◽  
Microbial Genomes ◽  
A Genome ◽  
Sequencing Studies ◽  
Metagenomics Data ◽  
Rrna Gene Sequencing

AbstractMetagenomics facilitates the study of the genetic information from uncultured microbes and complex microbial communities. Assembling complete microbial genomes (i.e., circular with no misassemblies) from metagenomics data is difficult because most samples have high organismal complexity and strain diversity. Less than 100 circularized bacterial and archaeal genomes have been assembled from metagenomics data despite the thousands of datasets that are available. Circularized genomes are important for (1) building a reference collection as scaffolds for future assemblies, (2) providing complete gene content of a genome, (3) confirming little or no contamination of a genome, (4) studying the genomic context and synteny of genes, and (5) linking protein coding genes to ribosomal RNA genes to aid metabolic inference in 16S rRNA gene sequencing studies. We developed a method to achieve circularized genomes using iterative assembly, binning, and read mapping. In addition, this method exposes potential misassemblies from k-mer based assemblies. We chose species of the Candidate Phyla Radiation (CPR) to focus our initial efforts because they have small genomes and are only known to have one ribosomal RNA operon. We present 34 circular CPR genomes, one circular Margulisbacteria genome, and two circular megaphage genomes from 19 public and published datasets. We demonstrate findings that would likely be difficult without circularizing genomes, including that ribosomal genes are likely not operonic in the majority of CPR, and that some CPR harbor diverged forms of RNase P RNA. Code and a tutorial for this method is available at https://github.com/lmlui/Jorg.

scholarly journals Ecofriendly Synthesis of Silver Nanoparticles by Terrabacter humi sp. nov. and Their Antibacterial Application against Antibiotic-Resistant Pathogens

2020 ◽  
Vol 21 (24) ◽  
pp. 9746
Author(s):  
Shahina Akter ◽  
Sun-Young Lee ◽  
Muhammad Zubair Siddiqi ◽  
Sri Renukadevi Balusamy ◽  
Md. Ashrafudoulla ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Spherical Shape ◽  
Optimal Growth ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Strictly Aerobic ◽  
Drug Resistant ◽  
Protein Coding ◽  
A Genome ◽  
The Fourier Transform

It is essential to develop and discover alternative eco-friendly antibacterial agents due to the emergence of multi-drug-resistant microorganisms. In this study, we isolated and characterized a novel bacterium named Terrabacter humi MAHUQ-38T, utilized for the eco-friendly synthesis of silver nanoparticles (AgNPs) and the synthesized AgNPs were used to control multi-drug-resistant microorganisms. The novel strain was Gram stain positive, strictly aerobic, milky white colored, rod shaped and non-motile. The optimal growth temperature, pH and NaCl concentration were 30 °C, 6.5 and 0%, respectively. Based on 16S rRNA gene sequence, strain MAHUQ-38T belongs to the genus Terrabacter and is most closely related to several Terrabacter type strains (98.2%–98.8%). Terrabacter humi MAHUQ-38T had a genome of 5,156,829 bp long (19 contigs) with 4555 protein-coding genes, 48 tRNA and 5 rRNA genes. The culture supernatant of strain MAHUQ-38T was used for the eco-friendly and facile synthesis of AgNPs. The transmission electron microscopy (TEM) image showed the spherical shape of AgNPs with a size of 6 to 24 nm, and the Fourier transform infrared (FTIR) analysis revealed the functional groups responsible for the synthesis of AgNPs. The synthesized AgNPs exhibited strong anti-bacterial activity against multi-drug-resistant pathogens, Escherichia coli and Pseudomonas aeruginosa. Minimal inhibitory/bactericidal concentrations against E. coli and P. aeruginosa were 6.25/50 and 12.5/50 μg/mL, respectively. The AgNPs altered the cell morphology and damaged the cell membrane of pathogens. This study encourages the use of Terrabacter humi for the ecofriendly synthesis of AgNPs to control multi-drug-resistant microorganisms.

scholarly journals Campylobacter insulaenigrae sp. nov., isolated from marine mammals

2004 ◽  
Vol 54 (6) ◽  
pp. 2369-2373 ◽  
Author(s):  
Geoffrey Foster ◽  
Barry Holmes ◽  
Arnold G. Steigerwalt ◽  
Paul A. Lawson ◽  
Petra Thorne ◽  
...  
Keyword(s):  
Dna Hybridization ◽  
Marine Mammals ◽  
16S Rrna Gene Sequencing ◽  
Single Species ◽  
Rrna Gene ◽  
Campylobacter Coli ◽  
Phylogenetic Studies ◽  
Sequencing Studies ◽  
Rrna Gene Sequencing ◽  
Campylobacter Lari

Phenotypic and phylogenetic studies were performed on four Campylobacter-like organisms recovered from three seals and a porpoise. Comparative 16S rRNA gene sequencing studies demonstrated that the organisms represent a hitherto unknown subline within the genus Campylobacter, associated with a subcluster containing Campylobacter jejuni, Campylobacter coli and Campylobacter lari. DNA–DNA hybridization studies confirmed that the bacteria belonged to a single species, for which the name Campylobacter insulaenigrae sp. nov. is proposed. The type strain of Campylobacter insulaenigrae sp. nov. is NCTC 12927T (=CCUG 48653T).

scholarly journals Utility of Histologic and Histochemical Screening for 16S Ribosomal RNA Gene Sequencing of Formalin-Fixed, Paraffin-Embedded Tissue for Bacterial Endocarditis

2019 ◽  
Vol 152 (4) ◽  
pp. 431-437 ◽  
Author(s):  
Isaac H Solomon ◽  
Chieyu Lin ◽  
Katharine L Horback ◽  
Sanjat Kanjilal ◽  
Vanesa Rojas-Rudilla ◽  
...  
Keyword(s):  
Ribosomal Rna ◽  
Gene Sequencing ◽  
Cost Savings ◽  
16S Rrna Gene Sequencing ◽  
16S Ribosomal Rna ◽  
Molecular Testing ◽  
Rrna Gene ◽  
Formalin Fixed Paraffin ◽  
Formalin Fixed Paraffin Embedded ◽  
Formalin Fixed

Abstract Objectives 16S ribosomal RNA (rRNA) sequencing is a powerful but expensive tool for the identification of bacteria in culture-negative endocarditis. Histologic criteria to screen formalin-fixed, paraffin-embedded (FFPE) specimens for testing are evaluated. Methods Sixty-eight cases of infective endocarditis and controls were histologically reviewed and analyzed by 16S rRNA gene sequencing. Results Sequencing identified a specific pathogenic organism in 33 (49%) of 68 cases with acute inflammation and in 0 of 10 controls (P = .004). Visualization of organisms by Gram or Grocott methenamine silver stains had the strongest association with positive sequencing, while antibiotic treatment effect and acid decalcification decreased sensitivity. Molecular identifications were concordant with blood culture results in 90% of the cases, and a positive sequencing result was obtained in approximately half of the cases with negative valve cultures. Conclusions Histologic screening criteria are extremely helpful for identifying cases likely to be positive by molecular testing and can provide significant cost savings in filtering out low-yield specimens.

Streptococcus orisasini sp. nov. and Streptococcus dentasini sp. nov., isolated from the oral cavity of donkeys

2013 ◽  
Vol 63 (Pt_8) ◽  
pp. 2782-2786 ◽  
Author(s):  
Kazuko Takada ◽  
Masanori Saito ◽  
Osamu Tsudukibashi ◽  
Takachika Hiroi ◽  
Masatomo Hirasawa
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Type Strain ◽  
Type Species ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Biochemical Tests ◽  
Content Type ◽  
Link Type ◽  
Sequencing Studies

Four Gram-positive, catalase-negative, coccoid isolates that were obtained from donkey oral cavities formed two distinct clonal groups when characterized by phenotypic and phylogenetic studies. From the results of biochemical tests, the organisms were tentatively identified as a streptococcal species. Comparative 16S rRNA gene sequencing studies confirmed the organisms to be members of the genus Streptococcus . Two of the isolates were related most closely to Streptococcus ursoris with 95.6 % similarity based on the 16S rRNA gene and to Streptococcus ratti with 92.0 % similarity based on the 60 kDa heat-shock protein gene (groEL). The other two isolates, however, were related to Streptococcus criceti with 95.0 and 89.0 % similarities based on the 16S rRNA and groEL genes, respectively. From both phylogenetic and phenotypic evidence, the four isolates formed two distinct clonal groups and are suggested to represent novel species of the genus Streptococcus . The names proposed for these organisms are Streptococcus orisasini sp. nov. (type strain NUM 1801T = JCM 17942T = DSM 25193T) and Streptococcus dentasini sp. nov. (type strain NUM 1808T = JCM 17943T = DSM 25137T).

scholarly journals Streptomyces panaciradicis sp. nov., a β-glucosidase-producing bacterium isolated from ginseng rhizoplane

2014 ◽  
Vol 64 (Pt_11) ◽  
pp. 3816-3820 ◽  
Author(s):  
Hyo-Jin Lee ◽  
Geon-Yeong Cho ◽  
Sang-Ho Chung ◽  
Kyung-Sook Whang
Keyword(s):  
Type Species ◽  
Taxonomic Status ◽  
16S Rrna Gene Sequencing ◽  
Diaminopimelic Acid ◽  
Rrna Gene ◽  
Content Type ◽  
Link Type ◽  
Gram Staining ◽  
Sequencing Studies ◽  
Biochemical Analyses

A Gram-staining-positive actinobacterium, designated strain 1MR-8T, was isolated from the rhizoplane of ginseng and its taxonomic status was determined using a polyphasic approach. The isolate formed long chains of spores that were straight, cylindrical and smooth-surfaced. Strain 1MR-8T grew at 10–37 °C (optimum 28 °C), whilst no growth was observed at 45 °C. The pH range for growth was 4.0–11.0 (optimum pH 6.0–8.0) and the NaCl range for growth was 0–7 % (w/v) with optimum growth at 1 % (w/v). Strain 1MR-8T had cell-wall peptidoglycans based on ll-diaminopimelic acid. Glucose, mannose and ribose were the whole-cell sugars. The predominant isoprenoid quinones were MK-9 (H4), MK-9 (H6) and MK-9 (H8) and the major fatty acids were anteiso-C15 : 0, iso-C15 : 0, anteiso-C17 : 0 and iso-C16 : 0. 16S rRNA gene sequencing studies showed that the novel strain was closely related to the type strains of Streptomyces caeruleatus GIMN4T, Streptomyces curacoi NRRL B-2901T, Streptomyces capoamus JCM 4734T and Streptomyces coeruleorubidus NBRC 12761T with similarities of 98.8 %. However, DNA–DNA relatedness, as well as physiological and biochemical analyses, showed that strain 1MR-8T could be differentiated from its closest phylogenetic relatives. It is proposed that this strain should be classified as a representative of a novel species of the genus Streptomyces , with the suggested name Streptomyces panaciradicis sp. nov. The type strain is 1MR-8T ( = KACC 17632T = NBRC 109811T).

scholarly journals Streptococcus loxodontisalivarius sp. nov. and Streptococcus saliviloxodontae sp. nov., isolated from oral cavities of elephants

2014 ◽  
Vol 64 (Pt_9) ◽  
pp. 3288-3292 ◽  
Author(s):  
Masanori Saito ◽  
Noriko Shinozaki-Kuwahara ◽  
Masatomo Hirasawa ◽  
Kazuko Takada
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Type Strain ◽  
Type Species ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Biochemical Tests ◽  
Content Type ◽  
Link Type ◽  
Sequencing Studies

Four Gram-stain-positive, catalase-negative, coccoid-shaped organisms were isolated from elephant oral cavities. The isolates were tentatively identified as streptococcal species based on the results of biochemical tests. Comparative 16S rRNA gene sequencing studies confirmed the organisms to be members of the genus Streptococcus . Two isolates (NUM 6304T and NUM 6312) were related most closely to Streptococcus salivarius with 96.8 % and 93.1 % similarity based on the 16S rRNA gene and the RNA polymerase β subunit encoding gene (rpoB), respectively, and to Streptococcus vestibularis with 83.7 % similarity based on the 60 kDa heat-shock protein gene (groEL). The other two isolates (NUM 6306T and NUM 6318) were related most closely to S. vestibularis with 97.0 % and 82.9 % similarity based on the 16S rRNA and groEL genes, respectively, and to S. salivarius with 93.5 % similarity based on the rpoB gene. Based on phylogenetic and phenotypic evidence, these isolates are suggested to represent novel species of the genus Streptococcus , for which the names Streptococcus loxodontisalivarius sp. nov. (type strain NUM 6304T = JCM 19287T = DSM 27382T) and Streptococcus saliviloxodontae sp. nov. (type strain NUM 6306T = JCM 19288T = DSM 27513T) are proposed.

scholarly journals Streptococcus ursoris sp. nov., isolated from the oral cavities of bears

2011 ◽  
Vol 61 (1) ◽  
pp. 40-44 ◽  
Author(s):  
Noriko Shinozaki-Kuwahara ◽  
Kazuko Takada ◽  
Masatomo Hirasawa
Keyword(s):  
Type Strain ◽  
16S Rrna Gene Sequencing ◽  
Extracellular Polysaccharide ◽  
Rrna Gene ◽  
The Novel ◽  
Biochemical Tests ◽  
Sequencing Studies ◽  
Streptococcal Species ◽  
Rrna Gene Sequencing ◽  
Streptococcus Ratti

Three Gram-positive, catalase-negative, coccus-shaped organisms were isolated from the oral cavities of bears. The isolates were tentatively identified as a streptococcal species based on the results of biochemical tests. Comparative 16S rRNA gene sequencing studies confirmed that the organisms were members of the genus Streptococcus, but they did not correspond to any recognized species of the genus. The nearest phylogenetic relative of the new isolates was Streptococcus ratti ATCC 19645T (98.6 %), however, DNA–DNA hybridization analysis showed that the isolates displayed less than 15 % DNA–DNA relatedness with the type strain of S. ratti. Colonies of the novel strains grown on mitis salivarius agar showed an extracellular polysaccharide-producing colony morphology. Based on phenotypic and phylogenetic evidence, it is proposed that the novel isolates are classified in the genus Streptococcus as Streptococcus ursoris sp. nov. The type strain of S. ursoris is NUM 1615T (=JCM 16316T=DSM 22768T).

scholarly journals Nocardia amamiensis sp. nov., isolated from a sugar-cane field in Japan

2007 ◽  
Vol 57 (7) ◽  
pp. 1599-1602 ◽  
Author(s):  
Hideki Yamamura ◽  
Tomohiko Tamura ◽  
Yayoi Sakiyama ◽  
Shigeaki Harayama
Keyword(s):  
Sugar Cane ◽  
16S Rrna Gene Sequencing ◽  
Treatment Method ◽  
Rrna Gene ◽  
Biochemical Tests ◽  
Sequencing Studies ◽  
Actinomycete Strain ◽  
Pre Treatment ◽  
Rrna Gene Sequencing ◽  
Type Strains

An actinomycete, strain TT 00-78T, was isolated from soil from a sugar-cane field on Amami Island in Japan, using an SDS/yeast extract pre-treatment method, and the taxonomy was studied using a polyphasic approach. The chemotaxonomic and morphological characterizations clearly demonstrated that the strain belongs to the genus Nocardia. 16S rRNA gene sequencing studies showed that the strain was closely related to the type strains of Nocardia pneumoniae (98.6 %), Nocardia araoensis (98.1 %), Nocardia arthritidis (97.9 %) and Nocardia beijingensis (97.7 %). However, the results of DNA–DNA hybridization and physiological and biochemical tests showed that strain TT 00-78T could be differentiated from its closest phylogenetic relatives both genotypically and phenotypically. Therefore this strain represents a novel species of the genus Nocardia, for which the name Nocardia amamiensis sp. nov. is proposed. The type strain is TT 00-78T (=NBRC 102102T=DSM 45066T=KCTC 19208T).

scholarly journals Metagenomic Analysis of the Viral Communities in Fermented Foods

2010 ◽  
Vol 77 (4) ◽  
pp. 1284-1291 ◽  
Author(s):  
Eun-Jin Park ◽  
Kyoung-Ho Kim ◽  
Guy C. J. Abell ◽  
Min-Soo Kim ◽  
Seong Woon Roh ◽  
...  
Keyword(s):  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Fermented Foods ◽  
Human Feces ◽  
Viral Genomes ◽  
Double Stranded Dna ◽  
Viral Communities ◽  
Rrna Gene Sequencing ◽  
Viral Sequences ◽  
Homology Comparison

ABSTRACTViruses are recognized as the most abundant biological components on Earth, and they regulate the structure of microbial communities in many environments. In soil and marine environments, microorganism-infecting phages are the most common type of virus. Although several types of bacteriophage have been isolated from fermented foods, little is known about the overall viral assemblages (viromes) of these environments. In this study, metagenomic analyses were performed on the uncultivated viral communities from three fermented foods, fermented shrimp, kimchi, and sauerkraut. Using a high-throughput pyrosequencing technique, a total of 81,831, 70,591 and 69,464 viral sequences were obtained from fermented shrimp, kimchi and sauerkraut, respectively. Moreover, 37 to 50% of these sequences showed no significant hit against sequences in public databases. There were some discrepancies between the prediction of bacteriophages hosts via homology comparison and bacterial distribution, as determined from 16S rRNA gene sequencing. These discrepancies likely reflect the fact that the viral genomes of fermented foods are poorly represented in public databases. Double-stranded DNA viral communities were amplified from fermented foods by using a linker-amplified shotgun library. These communities were dominated by bacteriophages belonging to the viral orderCaudovirales(i.e.,Myoviridae,Podoviridae, andSiphoviridae). This study indicates that fermented foods contain less complex viral communities than many other environmental habitats, such as seawater, human feces, marine sediment, and soil.

Sign in / Sign up

Export Citation Format

Share Document