scholarly journals Reclassification of the biocontrol agents Bacillus subtilis BY-2 and Tu-100 as Bacillus velezensis and insights into the genomic and specialized metabolite diversity of the species

Microbiology ◽  
2020 ◽  
Vol 166 (12) ◽  
pp. 1121-1128 ◽  
Author(s):  
Alex J. Mullins ◽  
Yinshui Li ◽  
Lu Qin ◽  
Xiaojia Hu ◽  
Lihua Xie ◽  
...  

The genomes of two historical Bacillus species strains isolated from the roots of oilseed rape and used routinely in PR China as biocontrol agents to suppress Sclerotinia disease were sequenced. Average nucleotide identity (ANI) and digital DNA–DNA hybridization analyses demonstrated that they were originally misclassified as Bacillus subtilis and now belong to the bacterial species Bacillus velezensis . A broader ANI analysis of available Bacillus genomes identified 292 B. velezensis genomes that were then subjected to core gene analysis and phylogenomics. Prediction and dereplication of specialized metabolite biosynthetic gene clusters (BGCs) defined the prevalence of multiple antimicrobial-associated BGCs and highlighted the natural product potential of B. velezensis . By defining the core and accessory antimicrobial biosynthetic capacity of the species, we offer an in-depth understanding of B. velezensis natural product capacity to facilitate the selection and testing of B. velezensis strains for use as biological control agents.

Author(s):  
Soon Dong Lee ◽  
In Seop Kim ◽  
Hanna Choe ◽  
Ji-Sun Kim

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.


Author(s):  
Inhyup Kim ◽  
Geeta Chhetri ◽  
Jiyoun Kim ◽  
Minchung Kang ◽  
Yoonseop So ◽  
...  

Two bacterial strains, designated MJB4T and SJ7T, were isolated from water samples collected from Jeongbang Falls on Jeju Island, Republic of Korea. Phylogenetic analysis of 16S rRNA gene sequences indicated that the two strains belonged to the genera Nocardioides and Hyunsoonleella , owing to their high similarities to Nocardioides jensenii DSM 29641T (97.5 %) and Hyunsoonleella rubra FA042 T (96.3 %), respectively. These values are much lower than the gold standard for bacterial species (98.7 %). The average nucleotide identity values between strains MJB4T, SJ7T and the reference strains, Nocardioides jensenii DSM 29641T, Nocardioides daejeonensis MJ31T and Hyunsoonleella flava T58T were 77.2, 75.9 and 75.4 %, respectively. Strains MJB4T and SJ7T and the type strains of the species involved in system incidence have average nucleotide identity and average amino acid threshold values of 60.1–82.6 % for the species boundary (95–96 %), which confirms that strains MJB4T and SJ7T represent two new species of genus Nocardioides and Hyunsoonleella , respectively. Based on phylogenetic and phenotypic data, strains MJB4T and SJ7T are considered to represent novel species of the genus Nocardioides and Hyunsoonleella , respectively, for which the names Nocardioides donggukensis sp. nov. (type strain MJB4T=KACC 21724T=NBRC 114402T) and Hyunsoonleella aquatilis sp. nov., (type strain SJ7T=KACC 21715T=NBRC 114486T) have been proposed.


Author(s):  
Lingmin Jiang ◽  
Won Yong Jung ◽  
Zhun Li ◽  
Mi-Kyung Lee ◽  
Seung-Hwan Park ◽  
...  

A Gram-stain-positive, facultatively anaerobic, endospore-forming, rod-shaped strain, AGMB 02131T, which grew at 20–40 °C (optimum 30 °C), pH 3.0–11.0 (optimum pH 4.0) and in the presence of 0–18 % (w/v) NaCl (optimum 10 %), was isolated from a cow faecal sample and identified as a novel strain using a polyphasic taxonomic approach. The phylogenetic analysis based on 16S rRNA gene sequences along with the whole genome (92 core gene sets) revealed that AGMB 02131T formed a group within the genus Peribacillus , and showed the highest sequence similarity with Peribacillus endoradicis DSM 28131T (96.9 %), following by Peribacillus butanolivorans DSM 18926T (96.6 %). The genome of AGMB 02131T comprised 70 contigs, the chromosome length was 4 038 965 bp and it had a 38.5 % DNA G+C content. Digital DNA–DNA hybridization revealed that AGMB 02131T displayed 21.4 % genomic DNA relatedness with the most closely related strain, P. butanolivorans DSM 18926T. AGMB 02131T contains all of the conserved signature indels that are specific for members of the genus Peribacillus . The major cellular fatty acids (>10 %) of AGMB 02131T were C18 : 1ω9c, C18:0 and C16 : 0. The major polar lipids present were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. On the basis of the phenotypic, phylogenetic, genomic and chemotaxonomic features, AGMB 02131T represents a novel species of the genus Peribacillus , for which the name Peribacillus faecalis sp. nov. is proposed. The type strain is AGMB 02131T (=KCTC 43221T=CCTCC AB 2020077T).


Author(s):  
Héléna Cuny ◽  
Clément Offret ◽  
Amine M. Boukerb ◽  
Leila Parizadeh ◽  
Olivier Lesouhaitier ◽  
...  

Three bacterial strains, named hOe-66T, hOe-124 and hOe-125, were isolated from the haemolymph of different specimens of the flat oyster Ostrea edulis collected in Concarneau bay (Finistère, France). These strains were characterized by a polyphasic approach, including (i) whole genome analyses with 16S rRNA gene sequence alignment and pangenome analysis, determination of the G+C content, average nucleotide identity (ANI), and in silico DNA–DNA hybridization (isDDH), and (ii) fatty acid methyl ester and other phenotypic analyses. Strains hOe-66T, hOe-124 and hOe-125 were closely related to both type strains Pseudoalteromonas rhizosphaerae RA15T and Pseudoalteromonas neustonica PAMC 28425T with less than 93.3% ANI and 52.3% isDDH values. Regarding their phenotypic traits, the three strains were Gram-negative, 1–2 µm rod-shaped, aerobic, motile and non-spore-forming bacteria. Cells grew optimally at 25 °C in 2.5% NaCl and at 7–8 pH. The most abundant fatty acids were summed feature 3 (C16:1 ω7c/C16:1 ω6c), C16:0 and C17:1 ω8c. The strains carried a genome average size of 4.64 Mb and a G+C content of 40.28 mol%. The genetic and phenotypic results suggested that strains hOe-66T, hOe-124 and hOe-125 belong to a new species of the genus Pseudoalteromonas . In this context, we propose the name Pseudoalteromonas ostreae sp. nov. The type strain is hOe-66T (=CECT 30303T=CIP 111911T).


Author(s):  
Ka Lip Chew ◽  
Sophie Octavia ◽  
Deborah Lai ◽  
Raymond T. P. Lin ◽  
Jeanette W. P. Teo

Staphylococcus argenteus and Staphylococcus schweitzeri are the newest members of the Staphylococcus aureus complex. The number of clinical reports attributed to these new S. aureus complex members is limited. In a retrospective clinical laboratory study conducted over a 4-month period investigating the prevalence of S. argenteus and S. schweitzeri , a total of 43 isolates were selected. Phylogeny based on core-gene multilocus sequence typing (MLST) analysis confirmed that 37 were S. argenteus but a genetically distinct clade of six isolates was identified. Digital DNA–DNA hybridization (dDDH) and average nucleotide identity (ANI) analyses further supported the classification of these six isolates as a separate species. When compared to S. aureus complex reference genomes, the ANI values were ≤94 % and the dDDH values were <53 %. Based on the seven-gene S. aureus MLST scheme, the six isolates belong to five novel allelic profiles (ST6105, ST6106, ST6107, ST6108 and ST109). Their clinical infection features were similar to S. aureus . Skin and soft tissue infections presented in four out of the six cases. Routine clinical diagnostic identification using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and biochemical profiling does not differentiate these new members from the rest of the complex. Genotypic analysis suggests that the six isolates belong to a novel species, Staphylococcus singaporensis sp. nov. with isolate SS21T (=DSM 111408T=NCTC14419T) designated as the type strain.


2015 ◽  
Vol 65 (Pt_2) ◽  
pp. 625-632 ◽  
Author(s):  
Javier Pascual ◽  
Marina García-López ◽  
Gerald F. Bills ◽  
Olga Genilloud

During the course of screening bacterial isolates as sources of as-yet unknown bioactive compounds with pharmaceutical applications, a chemo-organotrophic, Gram-negative bacterium was isolated from a soil sample taken from the Tejeda, Almijara and Alhama Natural Park, Granada, Spain. Strain F-278,770T was oxidase- and catalase-positive, aerobic, with a respiratory type of metabolism with oxygen as the terminal electron acceptor, non-spore-forming and motile by one polar flagellum, although some cells had two polar flagella. Phylogenetic analysis of the 16S rRNA, gyrB, rpoB and rpoD genes revealed that strain F-278,770T belongs to the Pseudomonas koreensis subgroup (Pseudomonas fluorescens lineage), with Pseudomonas moraviensis , P. koreensis , P. baetica and P. helmanticensis as its closest relatives. Chemotaxonomic traits such as polar lipid and fatty acid compositions and G+C content of genomic DNA corroborated the placement of strain F-278,770T in the genus Pseudomonas . DNA–DNA hybridization assays and phenotypic traits confirmed that this strain represents a novel species of the genus Pseudomonas , for which the name Pseudomonas granadensis sp. nov. is proposed. The type strain is F-278,770T ( = DSM 28040T = LMG 27940T).


2020 ◽  
Vol 70 (6) ◽  
pp. 3839-3844 ◽  
Author(s):  
Bingxia Dong ◽  
Sidong Zhu ◽  
Ting Chen ◽  
Na Ren ◽  
Xiunuan Chen ◽  
...  

A Gram-stain-negative bacterium, designated strain 501str8T, was isolated from a sediment sample collected from the East Pacific Ocean. 16S rRNA gene sequence analysis revealed that strain 501str8T belonged to the genus Muricauda , with closely related type strains Muricauda aquimarina SW-63T (98.5 %), Muricauda lutimaris SMK-108T (98.3 %) and Muricauda ruestringensis B1T (97.9 %). Up-to-date bacterial core gene set analysis revealed that strain 501str8T represented one independent lineage with M. aquimarina SW-63T. The average nucleotide identity values of strain 501str8T with M. aquimarina SW-63T and M. lutimaris SMK-108T were 80.2 and 81.3 %, respectively. In silico DNA–DNA hybridization values between strain 501str8T and M. aquimarina SW-63T and M. lutimaris SMK-108T were 22.8 and 32.9 %, respectively. The predominant isoprenoid quinone was menaquinone-6, and iso-C15 : 0, iso-C17 : 0 3-OH and iso-C15 : 1 G were the dominant cellular fatty acids. The G+C content of the genomic DNA was 42.8 mol%. Differential phylogenetic distinctiveness and chemotaxonomic differences, together with the phenotypic properties observed in this study, revealed that strain 501str8T could be differentiated from closely related species. Therefore, we propose that strain 501str8T represents a novel species of the genus Muricauda , for which the name Muricauda oceani sp. nov. is suggested. The type strain is 501str8T (=JCM 33902T=MCCC 1K04567T).


2020 ◽  
Vol 70 (5) ◽  
pp. 3547-3552 ◽  
Author(s):  
Mari Tohya ◽  
Shin Watanabe ◽  
Tatsuya Tada ◽  
Htay Htay Tin ◽  
Teruo Kirikae

This study was conducted to clarify the taxonomic status of the species Pseudomonas fuscovaginae and Pseudomonas shirazica . Whole genome sequences for the type strains of P. fuscovaginae and P. shirazica were compared against the closely related type strains of the Pseudomonas putida group and the Pseudomonas fluorescens group species. Average nucleotide identity and digital DNA–DNA hybridization values between P. fuscovaginae LMG 2158T and Pseudomonas asplenii ATCC 23835T were 98.4 and 85.5 %, and between P. shirazica VM14T and Pseudomonas asiatica RYU5T were 99.3 and 95.3 %. These values were greater than recognized thresholds for bacterial species delineation, indicating that they belong to the same genomospecies, respectively. Therefore, P. fuscovaginae and P. shirazica should be reclassified as later heterotypic synonyms of P. asplenii and P. asiatica , respectively.


2020 ◽  
Vol 70 (6) ◽  
pp. 3924-3929 ◽  
Author(s):  
Munusamy Madhaiyan ◽  
Venkatakrishnan Sivaraj Saravanan ◽  
Wah-Seng See-Too

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 .


2020 ◽  
Vol 70 (4) ◽  
pp. 2388-2394 ◽  
Author(s):  
Marvin A. Altamia ◽  
J. Reuben Shipway ◽  
David Stein ◽  
Meghan A. Betcher ◽  
Jennifer M. Fung ◽  
...  

A cellulolytic, aerobic, gammaproteobacterium, designated strain Bs02T, was isolated from the gills of a marine wood-boring mollusc, Bankia setacea (Bivalvia: Teredinidae). The cells are Gram-stain-negative, slightly curved motile rods (2–5×0.4–0.6 µm) that bear a single polar flagellum and are capable of heterotrophic growth in a simple mineral medium supplemented with cellulose as a sole source of carbon and energy. Cellulose, carboxymethylcellulose, xylan, cellobiose and a variety of sugars also support growth. Strain Bs02T requires combined nitrogen for growth. Temperature, pH and salinity optima (range) for growth were 20 °C (range, 10–30 °C), 8.0 (pH 6.5–8.5) and 0.5 M NaCl (range, 0.0–0.8 M), respectively when grown on 0.5 % (w/v) galactose. Strain Bs02T does not require magnesium and calcium ion concentrations reflecting the proportions found in seawater. The genome size is approximately 4.03 Mbp and the DNA G+C content of the genome is 47.8 mol%. Phylogenetic analyses based on 16S rRNA gene sequences, and on conserved protein-coding sequences, show that strain Bs02T forms a well-supported clade with Teredinibacter turnerae . Average nucleotide identity and percentage of conserved proteins differentiate strain Bs02T from Teredinibacter turnerae at threshold values exceeding those proposed to distinguish bacterial species but not genera. These results indicate that strain Bs02T represents a novel species in the previously monotypic genus Teredinibacter for which the name Teredinibacter waterburyi sp. nov. is proposed. The strain has been deposited under accession numbers ATCC TSD-120T and KCTC 62963T.


Sign in / Sign up

Export Citation Format

Share Document