scholarly journals Isolation, Phylogenetic and Gephyromycin Metabolites Characterization of New Exopolysaccharides-Bearing Antarctic Actinobacterium from Feces of Emperor Penguin

Marine Drugs ◽  
2021 ◽  
Vol 19 (8) ◽  
pp. 458
Author(s):  
Hui-Min Gao ◽  
Peng-Fei Xie ◽  
Xiao-Ling Zhang ◽  
Qiao Yang
Keyword(s):  
Genome Mining ◽  
Pairwise Comparison ◽  
Gene Clusters ◽  
Amino Acid Identity ◽  
Core Gene ◽  
Emperor Penguin ◽  
Rrna Gene ◽  
Active Metabolites ◽  
The Antarctic ◽  
Gene Similarity

A new versatile actinobacterium designated as strain NJES-13 was isolated from the feces of the Antarctic emperor penguin. This new isolate was found to produce two active gephyromycin analogues and bioflocculanting exopolysaccharides (EPS) metabolites. Phylogenetic analysis based on pairwise comparison of 16S rRNA gene sequences showed that strain NJES-13 was closely related to Mobilicoccus pelagius Aji5-31T with a gene similarity of 95.9%, which was lower than the threshold value (98.65%) for novel species delineation. Additional phylogenomic calculations of the average nucleotide identity (ANI, 75.9–79.1%), average amino acid identity (AAI, 52.4–66.9%) and digital DNA–DNA hybridization (dDDH, 18.6–21.9%), along with the constructed phylogenomic tree based on the up-to-date bacterial core gene (UBCG) set from the bacterial genomes, unequivocally separated strain NJES-13 from its close relatives within the family Dermatophilaceae. Hence, it clearly indicated that strain NJES-13 represented a putative new actinobacterial species isolated from the gut microbiota of mammals inhabiting the Antarctic. The obtained complete genome of strain NJES-13 consisted of a circular 3.45 Mb chromosome with a DNA G+C content of 67.0 mol%. Furthering genome mining of strain NJES-13 showed the presence of five biosynthetic gene clusters (BGCs) including one type III PKS responsible for the biosynthesis of the core of gephyromycins, and a series of genes encoding for bacterial EPS biosynthesis. Thus, based on the combined phylogenetic and active metabolites characterization presented in this study, we confidently conclude that strain NJES-13 is a novel, fresh actinobacterial candidate to produce active gephyromycins and microbial bioflocculanting EPS, with potential pharmaceutical, environmental and biotechnological implications.

scholarly journals Isolation and Identification of Actinomycetes Strains from Switzerland and their Biotechnological Potential

2020 ◽  
Vol 74 (5) ◽  
pp. 382-390 ◽  
Author(s):  
Fabienne Arn ◽  
David Frasson ◽  
Ivana Kroslakova ◽  
Fabio Rezzonico ◽  
Joël F. Pothier ◽  
...  
Keyword(s):  
Draft Genome ◽  
Genome Mining ◽  
Bioactive Compound ◽  
Gene Clusters ◽  
Natural Compounds ◽  
Rrna Gene ◽  
Cultivation Conditions ◽  
Screening Assay ◽  
Isolation And Identification ◽  
Bioinformatics Analyses

Actinomycetes strains isolated from different habitats in Switzerland were investigated for production of antibacterial and antitumoral compounds. Based on partial 16S rRNA gene sequences, the isolated strains were identified to genus level. Streptomyces as the largest genus of Actinobacteriawas isolated the most frequently. A screening assay using the OmniLog instrument was established to facilitate the detection of active compounds from actinomycetes. Extracts prepared from the cultivated strains able to inhibit Staphylococcus aureusand Escherichia coliwere further analysed by HPLC and MALDI-TOF MS to identify the produced antibiotics. In this study, the bioactive compound echinomycin was identified from two isolated Streptomycesstrains. Natural compounds similar to TPU-0037-C, azalomycin F4a 2-ethylpentyl ester, a derivative of bafilomycin A1, milbemycin-α8 and dihydropicromycin were detected from different isolated Streptomyces strains. Milbemycin-α8 showed cytotoxic activity against HT-29 colon cancer cells. The rare actinomycete,Micromonospora sp. Stup16_C148 produced a compound that matches with the antibiotic bottromycin A2. The draft genome sequence from Actinokineospora strain B136.1 was determined using Illumina and nanopore-based technologies. The isolated strain was not able to produce antibacterial compounds under standard cultivation conditions. The antiSMASH bioinformatics analyses of the genome from strain B136.1 identified biosynthetic gene clusters with identity values between 4% to 90% to known gene clusters encoding antibiotics. The combinations of cultivation conditions, screening assays, analytical methods and genome mining are important tools to characterize strains of actinomycetes for the identification of their potential to produce natural compounds with antimicrobial activity.

Acerihabitans arboris gen. nov., sp. nov., a new member of the family Pectobacteriaceae isolated from sap drawn from Acer pictum

2021 ◽  
Author(s):  
Soon Dong Lee ◽  
In Seop Kim ◽  
Hanna Choe ◽  
Ji-Sun Kim
Keyword(s):  
Type Species ◽  
Sequence Similarity ◽  
Taxonomic Status ◽  
Amino Acid Identity ◽  
Core Gene ◽  
Phylogenomic Analysis ◽  
Rrna Gene ◽  
Content Type ◽  
Link Type ◽  
The Family

A Gram-negative, facultatively anaerobic bacterium, designated SAP-6T, was isolated from sap extracted from Acer pictum in Mt. Halla in Jeju, Republic of Korea and its precise taxonomic status was determined by a polyphasic approach. Cells were non-sporulating, motile, short rods and showed growth at 4–37 °C, pH 6.0–8.0 and 0–4% NaCl. Phylogenomic analysis based on 92 core gene sequences showed that strain SAP-6T belonged to the family Pectobacteriaceae and formed a distinct clade between members of the genera Sodalis and Biostraticola with gene support index of 89. The closest phylogenetic neighbours were Biostraticola tofi DSM 19580T (97.3% 16S rRNA gene sequence similarity) and Sodalis praecaptivus HS1T (96.8%), with the average amino acid identity values of 75.3% and 74.0%, respectively. The major polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol and an unidentified aminophospholipid. The major isoprenoid quinones were Q-7 and Q-8. The predominant fatty acids were C16:0, C17:0 cyclo and summed feature 3. The DNA G+C content was 57.0%. On the basis of data presented here, strain SAP-6T (=KCTC 52622T=DSM 104038T) represents a novel species of a new genus in the family Pectobacteriaceae , for which the name Acerihabitans arboris gen. nov., sp. nov. is proposed.

Acuticoccus mangrovi sp. nov., with an antibacterial property, isolated from mangrove sediment

2021 ◽  
Vol 71 (12) ◽  
Author(s):  
Zhe Li ◽  
Wenjin Hu ◽  
Shushi Huang ◽  
Yuanlin Huang ◽  
Fei Li ◽  
...  
Keyword(s):  
Gene Clusters ◽  
Amino Acid Identity ◽  
Mangrove Sediment ◽  
Species Discrimination ◽  
Rrna Gene ◽  
Beibu Gulf ◽  
Respiratory Quinone ◽  
Content Type ◽  
Link Type ◽  
Sequence Relatedness

A Gram-stain-negative, aerobic, milky white bacterium, designated B2012T, was isolated from mangrove sediment collected at Beibu Gulf, South China Sea. Antimicrobial activity assay revealed that the isolate possesses the capability of producing antibacterial compounds. Strain B2012T shared the highest 16S rRNA gene sequence relatedness (96.9–95.5 %) with members of the genus Acuticoccus . The isolate and all known Acuticoccus species contain Q-10 as the main respiratory quinone and have the same polar lipid components (phosphatidylcholine, unidentified glycolipid, unidentified lipid, unidentified amino lipid and phosphatidylglycerol). However, genomic relatedness referred by values of average nucleotide identity, digital DNA–DNA hybridization, average amino acid identity and the percentage of conserved proteins between strain B2012T and other type strains of the genus Acuticoccus were below the proposed thresholds for species discrimination. The genome of strain B2012T was assembled into 65 scaffolds with an N50 size of 244239 bp, resulting in a 5.5 Mb genome size. Eight secondary metabolite biosynthetic gene clusters were detected in this genome, including three non-ribosomal peptide biosynthetic loci encoding yet unknown natural products. Strain B2012T displayed moderately halophilic and alkaliphilic properties, growing optimally at 2–3 % (w/v) NaCl concentration and at pH 8–9. The major cellular fatty acids (>10 %) were anteiso-C15 : 0, C16 : 0 dimethyl aldehyde (DMA) and C16 : 0. Combined data from phenotypic, genotypic and chemotaxonomic analyses suggested that strain B2012T represents a novel species of the genus Acuticoccus , for which the name Acuticoccus mangrovi sp. nov. is proposed. The type strain of the type species is B2012T (=MCCC 1K04418T=KCTC 72962T).

scholarly journals Culturable diversity of bacterial endophytes associated with medicinal plants of the Western Ghats, India

2020 ◽  
Author(s):  
Gordon Webster ◽  
Alex J Mullins ◽  
Edward Cunningham-Oakes ◽  
Arun Renganathan ◽  
Jamuna Bai Aswathanarayan ◽  
...  
Keyword(s):  
Medicinal Plants ◽  
Western Ghats ◽  
16S Rrna Gene Sequencing ◽  
Gene Clusters ◽  
Core Gene ◽  
Rrna Gene ◽  
Bacterial Endophytes ◽  
Rrna Gene Sequencing ◽  
Multiple Species ◽  
The Western Ghats

Abstract Bacterial endophytes are found in the internal tissues of plants and have intimate associations with their host. However, little is known about the diversity of medicinal plant endophytes (ME) or their capability to produce specialised metabolites that may contribute to therapeutic properties. We isolated 75 bacterial ME from 24 plant species of the Western Ghats, India. Molecular identification by 16S rRNA gene sequencing grouped MEs into 13 bacterial genera, with members of Gammaproteobacteria and Firmicutes being the most abundant. To improve taxonomic identification, 26 selected ME were genome sequenced and average nucleotide identity (ANI) used to identify them to the species-level. This identified multiple species in the most common genus as Bacillus. Similarly, identity of the Enterobacterales was also distinguished within Enterobacter and Serratia by ANI and core-gene analysis. AntiSMASH identified non-ribosomal peptide synthase, lantipeptide and bacteriocin biosynthetic gene clusters (BGC) as the most common BGCs found in the ME genomes. Five of the ME isolates belonging to Bacillus, Serratia and Enterobacter showed antimicrobial activity against the plant pathogen Pectobacterium carotovorum. Using molecular and genomic approaches we have characterised a unique collection of endophytic bacteria from medicinal plants. Their genomes encode multiple specialised metabolite gene clusters and the collection can now be screened for novel bioactive and medicinal metabolites.

scholarly journals Genome-based analyses reveal the presence of 12 heterotypic synonyms in the genus Streptomyces and emended descriptions of Streptomyces bottropensis, Streptomyces celluloflavus, Streptomyces fulvissimus, Streptomyces glaucescens, Streptomyces murinus, and Streptomyces variegatus

2020 ◽  
Vol 70 (6) ◽  
pp. 3924-3929 ◽  
Author(s):  
Munusamy Madhaiyan ◽  
Venkatakrishnan Sivaraj Saravanan ◽  
Wah-Seng See-Too
Keyword(s):  
Type Species ◽  
Sequence Similarity ◽  
Orthologous Gene ◽  
Gene Clusters ◽  
Amino Acid Identity ◽  
Rrna Gene ◽  
Genus Streptomyces ◽  
Content Type ◽  
Link Type ◽  
Streptomyces Glaucescens

Phylogenetic analysis based on 16S rRNA gene sequences of the genus Streptomyces showed the presence of six distinguishable clusters, with 100 % sequence similarity values among strains in each cluster; thus they shared almost the same evolutionary distance. This result corroborated well with the outcome of core gene (orthologous gene clusters) based genome phylogeny analysis of 190 genomes including the Streptomyces species in those six clusters. These preeminent results led to an investigation of genome-based indices such as digital DNA–DNA hybridization (dDDH), average nucleotide identity (ANI) and average amino acid identity (AAI) for the strains in those six clusters. Certain strains recorded genomic indices well above the threshold values (70 %, 95–96 % and >95 % for dDDH, ANI and AAI, respectively) determined for species affiliation, suggesting only one type strain belongs to described species and the other(s) may need to be reduced in taxa to a later heterotypic synonym. To conclude, the results of comprehensive analyses based on phylogenetic and genomic indices suggest that the following six reclassifications are proposed: Streptomyces flavovariabilis as a later heterotypic synonym of Streptomyces variegatus ; Streptomyces griseofuscus as a later heterotypic synonym of Streptomyces murinus ; Streptomyces kasugaensis as a later heterotypic synonym of Streptomyces celluloflavus ; Streptomyces luridiscabiei as a later heterotypic synonym of Streptomyces fulvissimus ; Streptomyces pharetrae as a later heterotypic synonym of Streptomyces glaucescens ; and Streptomyces stelliscabiei as a later heterotypic synonym of Streptomyces bottropensis .

scholarly journals Rhodobacter ruber sp. nov., isolated from a freshwater pond

2021 ◽  
Author(s):  
Wen-Ming Chen ◽  
Ting-Hsuan Chang ◽  
Der-Shyan Sheu ◽  
Li-Cheng Jheng ◽  
Shih-Yi Sheu
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Novel Species ◽  
Sequence Similarity ◽  
Phylogenetic Analyses ◽  
Amino Acid Identity ◽  
Core Gene ◽  
Rrna Gene ◽  
Freshwater Pond ◽  
Average Amino Acid Identity

Abstract Strain CCP-1T, isolated from a freshwater pond in Taiwan, is characterized using a polyphasic taxonomy approach. Cells of strain CCP-1T are Gram-stain-negative, aerobic, non-motile, rod-shaped and form dark red colored colonies. Growth occurs at 20–40 oC, at pH 6.5-9 and with 0-0.5% NaCl. Strain CCP-1T contains bacteriochlorophyll a, and shows optimum growth under anaerobic condition by photoheterotrophy, but not by photoautotrophy. 16S rRNA gene sequence similarity indicates that strain CCP-1T is closely related to species within the genus Rhodobacter (93.9–96.2% sequence similarity), Haematobacter (96.3%) and Xinfangfangia (95.5–96.2%). Phylogenetic analyses based on 16S rRNA gene sequences and based on up-to-date bacterial core gene set (92 protein clusters) reveal that strain CCP-1T is affiliated with species in the genus Rhodobacter. The average nucleotide identity, average amino acid identity and digital DNA-DNA hybridization identity between strain CCP-1T and Rhodobacter species are 71.3–76.3%, 70.4–77.9% and 21.4–23.2%, respectively, supporting that strain CCP-1T is a novel species of the genus Rhodobacter. The DNA G + C content is 66.2%. The predominant fatty acid is C18:1ω7c and the major isoprenoid quinone is Q-10. The polar lipids have phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, two uncharacterized aminophospholipids and two uncharacterized phospholipids. On the basis of phenotypic and genotypic properties and phylogenetic inference, strain CCP-1T should represent a novel species of the genus Rhodobacter, for which the name Rhodobacter ruber sp. nov. is proposed. The type strain is CCP-1T (= BCRC 81189T = LMG 31335T).

scholarly journals Genomic and phylogenomic insights into the family Streptomycetaceae lead to proposal of Charcoactinosporaceae fam. nov. and 8 novel genera with emended descriptions of Streptomyces calvus

2020 ◽  
Author(s):  
Munusamy Madhaiyan ◽  
Venkatakrishnan Sivaraj Saravanan ◽  
Wah-Seng See-Too
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Phylogenetic Trees ◽  
Gene Clusters ◽  
Tree Topology ◽  
Phylogenomic Analysis ◽  
Rrna Gene ◽  
The Family ◽  
Genome Phylogeny ◽  
Gene Similarity

AbstractStreptomycetaceae is one of the oldest families within phylum Actinobacteria and it is large and diverse in terms of number of described taxa. The members of the family are known for their ability to produce medically important secondary metabolites and antibiotics. In this study, strains showing low 16S rRNA gene similarity (<97.3 %) with other members of Streptomycetaceae were identified and subjected to phylogenomic analysis using 33 orthologous gene clusters (OGC) for accurate taxonomic reassignment resulted in identification of eight distinct and deeply branching clades, further average amino acid identity (AAI) analysis showed lower AAI values or AAI within the range of 60-80 % which was previously observed in related but different genera of bacteria. The whole genome phylogeny based on concatenated core genes and AAI analyses supported the claim that those phylogenetically distinct members may be assigned to 8 novel genera namely Actinoacidiphila, Actinomesophilus, Charcoactinospora, Curviacidiphilus, Kafeoacidiphilus, Mangroviactinospora, Peterkaempfera, and Streptantibioticus. In addition, based on the core genome phylogeny and 16S rRNA tree topology and distinct chemotaxonomic and physiological properties, the sequence belonged to Streptomyces thermoautotrophicus was assigned to a novel genera Charcoactinospora which is placed under novel family Charcoactinosporaceae. Lastly, a clade comprising of strains that showed high 16S rRNA gene similarity (100 %) with similar tree topology in phylogenetic trees was subjected to overall genome related indices analyses such as digital DNA – DNA hybridization, and average nucleotide identity that supported the claim that Streptomyces asterosporus is a later heterotypic synonym of Streptomyces calvus.

scholarly journals Reconstituting the genus Mycobacterium

2021 ◽  
Vol 71 (9) ◽  
Author(s):  
Conor J. Meehan ◽  
Roman A. Barco ◽  
Yong-Hwee E. Loh ◽  
Sari Cogneau ◽  
Leen Rigouts
Keyword(s):  
Amino Acid Identity ◽  
Evolutionary Relationships ◽  
Rrna Gene ◽  
New Genera ◽  
Opportunistic Pathogens ◽  
Content Type ◽  
Link Type ◽  
Genus Mycobacterium ◽  
Definition Of ◽  
Gene Similarity

The definition of a genus has wide-ranging implications both in terms of binomial species names and also evolutionary relationships. In recent years, the definition of the genus Mycobacterium has been debated due to the proposed split of this genus into five new genera ( Mycolicibacterium , Mycolicibacter , Mycolicibacillus , Mycobacteroides and an emended Mycobacterium ). Since this group of species contains many important obligate and opportunistic pathogens, it is important that any renaming of species does not cause confusion in clinical treatment as outlined by the nomen periculosum rule (56a) of the Prokaryotic Code. In this study, we evaluated the proposed and original genus boundaries for the mycobacteria, to determine if the split into five genera was warranted. By combining multiple approaches for defining genus boundaries (16S rRNA gene similarity, amino acid identity index, average nucleotide identity, alignment fraction and percentage of conserved proteins) we show that the original genus Mycobacterium is strongly supported over the proposed five-way split. Thus, we propose that the original genus label be reapplied to all species within this group, with the proposed five genera potentially used as sub-genus complex names.

scholarly journals Actinoplanes aureus sp. nov., a novel protease-producing actinobacterium isolated from soil

2021 ◽  
Author(s):  
Xiujun Sun ◽  
Xianxian Luo ◽  
Chuan He ◽  
Zhenzhen Huang ◽  
Junwei Zhao ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Type Strain ◽  
Genome Mining ◽  
Gene Clusters ◽  
Diaminopimelic Acid ◽  
Rrna Gene ◽  
Protein Coding ◽  
Putative Gene ◽  
A Genome

Abstract A novel protease-producing actinobacterium, designated strain NEAU-A11T, was isolated from soil collected from Aohan banner, Chifeng, Inner Mongolia Autonomous Region, China, and characterised using a polyphasic approach. On the basis of 16S rRNA gene sequence analysis, strain NEAU-A11T was indicated to belong to the genus Actinoplanes and was most closely related to Actinoplanes rectilineatus JCM 3194T (98.9 %). Cell walls contained meso-diaminopimelic acid as the diagnostic diamino acid and the whole-cell sugars were arabinose, xylose and glucose. The phospholipid profile contained diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol and two phosphatidylinositol mannosides. The predominant menaquinones were MK-9(H4), MK-9(H6) and MK-9(H8). The major fatty acids were C18:0, C16:0, C18:1 ω9c, C17:0 and C15:0. Genome sequencing revealed a genome size of 10,742,096 bp, a G + C content of 70.5 % and 9,514 protein-coding genes (CDSs), including 102 genes coding for protease. Genome mining analysis using antiSMASH 5.0 led to the identification of 20 putative gene clusters responsible for the production of diverse secondary metabolites. Phylogenetic analysis using the 16S rRNA gene sequences showed that the strain formed a stable clade with A. rectilineatus JCM 3194T in the genus Actinoplanes. However, whole-genome average nucleotide identity (ANI) value and the levels of digital DNA-DNA (dDDH) hybridization between strain NEAU- A11T and A. rectilineatus JCM 3194T was 81.1 % and 24.6 % (22.2–27.0 %), respectively. The values were well below the criteria for species delineation of 70% for dDDH and 95–96% for ANI, suggesting that the isolate differed genetically from its closely related type strain. In addition, evidences from phenotypic, chemotaxonomic and genotypic studies indicate that strain NEAU-A11T represents a novel species of the genus Actinoplanes, for which the name Actinoplanes aureus sp. nov. is proposed, with NEAU-A11T (= CCTCC AA 2019063T = JCM 33971T) as the type strain.

Thermosynergistes pyruvativorans gen. nov., sp. nov., an anaerobic, pyruvate-degrading bacterium from Shengli oilfield, and proposal of Thermosynergistaceae fam. nov. in the phylum Synergistetes

2021 ◽  
Vol 71 (9) ◽  
Author(s):  
Min Yang ◽  
Jiang Li ◽  
Xiao-meng Lv ◽  
Li-rong Dai ◽  
Ke-jia Wu ◽  
...  
Keyword(s):  
Cellular Fatty Acid ◽  
Amino Acid Identity ◽  
Oily Sludge ◽  
Rrna Gene ◽  
Strictly Anaerobic ◽  
Content Type ◽  
Link Type ◽  
Degrading Bacterium ◽  
Shengli Oilfield ◽  
Gene Similarity

A strictly anaerobic, thermophilic, Gram-stain-negative bacterium, named as strain S15T, was isolated from oily sludge of Shengli oilfield in PR China. Cells of strain S15T were straight or slightly curved rods with 0.4–0.8 µm width × 1.4–3 µm length and occurred mostly in pairs or short chains. Endospore-formation was not observed. The strain grew optimally at 55 °C (range from 30–65 °C), pH 6.5 (pH 6.0–8.5) and 0–30 g l−1 NaCl (optimum with 10 g l−1 NaCl). Yeast extract was an essential growth factor for strain S15T. The major cellular fatty acid was iso-C15 : 0 (58.2 %), and the main polar lipids were amino phospholipid (APL), glycolipids (GLs) and phosphatidylethanolamine (PE). The G+C content of DNA of strain S15T was 52.2 mol%. Strain S15T shared 89.8 % 16S rRNA gene similarity with the most related organism Acetomicrobium hydrogeniformans DSM 22491T in the phylum Synergistetes . The paired genomic average amino acid identity (AAI) and percentage of conserved proteins (POCP) values showed relatedness of less than 58.0 and 39.7 % with type strains of the species in the phylum Synergistetes . On the basis of phenotypic, phylogenetic and phylogenomic evidences, strain S15T constitutes a novel species in a novel genus, for the name Thermosynergistes pyruvativorans gen. nov., sp. nov. is proposed. The type strain is S15T (=CCAM 583T=JCM 33159T). Thermosynergistaceae fam. nov. is also proposed.

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