BGCFlow: systematic pangenome workflow for the analysis of biosynthetic gene clusters across large genomic datasets

Genome mining is revolutionizing natural products discovery efforts. The rapid increase in available genomes demands comprehensive computational platforms to effectively extract biosynthetic knowledge encoded across bacterial pangenomes. Here, we present BGCFlow, a novel systematic workflow integrating analytics for large-scale genome mining of bacterial pangenomes. BGCFlow incorporates several genome analytics and mining tools grouped into five common stages of analysis such as: (i) data selection, (ii) functional annotation, (iii) phylogenetic analysis, (iv) genome mining, and (v) comparative analysis. Furthermore, BGCFlow provides easy configuration of different projects, parallel distribution, scheduled job monitoring, an interactive database to visualize tables, exploratory Jupyter Notebooks, and customized reports. Here, we demonstrate the application of BGCFlow by investigating the phylogenetic distribution of various biosynthetic gene clusters detected across 42 genomes of the Saccharopolyspora genus, known to produce industrially important secondary/specialized metabolites. The BGCFlow-guided analysis predicted more accurate dereplication of BGCs and guided the targeted comparative analysis of selected RiPPs. The scalable, interoperable, adaptable, re-entrant, and reproducible nature of the BGCFlow will provide an effective novel way to extract the biosynthetic knowledge from the ever-growing genomic datasets of biotechnologically relevant bacterial species.

Saccharopolyspora soli sp. nov., isolated from Northern Cyprus soil

A novel Gram-stain positive, aerobic, non-motile actinobacterium, designated strain K220^T, was isolated from soil collected from Cape Andreas (Zafer Burnu), Northern Cyprus, and subjected to a polyphasic taxonomic approach. The organism was shown to have phylogenetic, chemotaxonomic, cultural and morphological properties consistent with its classification in the genus Saccharopolyspora. 16S rRNA gene sequence analysis of strain K220^T showed that it is closely related to the type strains of Saccharopolyspora maritima 3SS5-12 ^T, Saccharopolyspora kobensis JCM 9109 ^T and Saccharopolyspora hirsuta ATCC 27875 ^T with 97.6, 97.5 and 97.0% sequence similarity, respectively. In silico DNA-DNA hybridization and average nucleotide identity values between strain K220^T and type strains of the genus Saccharopolyspora with publicly available genomes were 22.1-31.2% and 76.0-83.16%, respectively. The DNA G + C content of strain K220^T was 68.3 mol%. The genome of strain K220^T has genes associated with 24 biosynthetic gene clusters. The strain contained MK-9(H₄) and iso-C_16: 0 as the predominant respiratory quinone and fatty acid, respectively. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine. Based on evidence collected from the genotypic, phenotypic and phylogenetic analyses, strain K220^T is considered to represent a novel species in the genus Saccharopolyspora, for which the name Saccharopolyspora soli sp. nov. is proposed. The type strain is K220^T (= JCM 33912^T = KCTC 49395^T).

Saccharopolyspora coralli sp. nov. a novel actinobacterium isolated from the stony coral Porites

A novel Gram-stain-positive, aerobic, non-motile actinobacterium, designated strain E2A^T, was isolated from a coral sample and examined using a polyphasic taxonomic approach. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain E2A^T formed a distinct phyletic lineage in the genus Saccharopolyspora and was closely related to S. cavernae CCTCC AA 2012022^T (96.4 %) and S. lacisalsi CCTCC AA 2010012^T (95.3 %). The isolate grew at 15-35 °C, pH 5-12 and in the presence of 1-16 % (w/v) NaCl. The cell-wall diamino acid was meso-DAP. Major fatty acids identified were iso-C_15 : 0, iso-C_16 : 0 and C_17 : 1  ω8c. The predominant menaquinone was MK-9(H₄). The polar lipids detected were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylmethylethanolamine, one unidentified glycolipid, one unidentified phospholipid and one unidentified aminolipid. The genomic DNA G+C content was 68.6 mol%. Based on the data from the polyphasic taxonomic study reported here, strain E2A^T represents a novel species within the genus Saccharopolyspora, for which the name Saccharopolyspora coralli sp. nov. is proposed. The type strain is E2A^T=(JCM 31844^T=MCCC 1A17150^T).

Saccharopolyspora rhizosphaerae sp. nov., an actinomycete isolated from rhizosphere soil in Thailand

A novel actinomycete, designated as strain H219^T, was isolated from rhizosphere soil collected under an Elephant ear plant (Colocasiaesculenta) in Bangkok, Thailand. Strain H219^T was characterised using a polyphasic approach. Phylogenetic analysis of the 16S rRNA gene sequences revealed that this isolate was most closely related to Saccharopolyspora tripterygii JCM 32123^T (97.6 %), Saccharopolyspora dendranthemae NBRC 108675^T (97.5 %) and Saccharopolyspora flava NBRC 16345^T (97.5 %). However, DNA-DNA hybridization analyses showed a low relatedness in the range of 39-48 % between the novel isolate and the above closely related strains. The cell-wall peptidoglycan of strain H219^T contained meso-diaminopimelic acid. The diagnostic whole-cell sugars consisted of arabinose and galactose. The cellular fatty acid profile mainly comprised iso-C16 : 0, anteiso-C17 : 0, iso-C15 : 0, and 10-methyl C17 : 0. The major menaquinone was MK-9(H4). The detected phospholipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylethanolamine-containing hydroxylated fatty acids and an unknown phospholipid. The DNA G+C content was 70.6 mol%. Strain H219^T represented chemotaxonomic and morphological characteristics that were consistent with members of the genus Saccharopolyspora. However, strain H219^T could be distinguished from closely related strains by several phenotypic properties. Based on the data from the polyphasic studies, we propose that strain H219^T is a novel species within the genus Saccharopolyspora, Saccharopolysporarhizosphaerae sp. nov. The type strain is H219^T (=TBRC 8564^T=NBRC 113388^T).

Saccharopolyspora spongiae sp. nov., a novel actinomycete isolated from the marine sponge Scopalina ruetzleri (Wiedenmayer, 1977)

A novel marine actinomycete, designated strain CMAA 1452T, was isolated from the sponge Scopalina ruetzleri collected from Saint Peter and Saint Paul Archipelago, in Brazil, and subjected to a polyphasic taxonomic investigation. The organism formed a distinct phyletic line in the Saccharopolyspora 16S rRNA gene tree and had chemotaxonomic and morphological properties consistent with its classification in this genus. It was found to be closely related to Saccharopolyspora dendranthemae KLBMP 1305T (99.5% 16S rRNA gene sequence similarity) and shared similarities of 99.3, 99.2 and 99.0 % with 'Saccharopolyspora endophytica' YIM 61095, Saccharopolyspora tripterygii YIM 65359T and 'Saccharopolyspora pathumthaniensis' S582, respectively. DNA-DNA relatedness values between the isolate and its closest phylogenetic neighbours, namely S. dendranthemae KLBMP 1305T, 'S. endophytica' YIM 61095 and S. tripterygii YIM 65359T, were 53.5, 25.8 and 53.2 %, respectively. Strain CMAA 1452T was also distinguished from the type strains of these species using a range of phenotypic features. On the basis of these results, it is proposed that strain CMAA 1452T (=DSM 103218T=NRRL B-65384T) merits recognition as the type strain of a novel Saccharopolyspora species, Saccharopolyspora spongiae sp. nov.

Saccharopolyspora halotolerans sp. nov., a halophilic actinomycete isolated from a hypersaline lake

A novel actinomycete strain, designated TRM 45123T, was isolated from a hypersaline habitat in Xinjiang Province (40° 20′ N 90° 49′ E), north-west China. The isolate was characterized using a polyphasic approach. 16S rRNA gene sequence analysis indicated that strain TRM 45123T belonged to the genus Saccharopolyspora and was closely related to Saccharopolyspora gloriosae (96.7 % similarity). The G+C content of the DNA was 69.07 mol%. The isolate contained meso-diaminopimelic acid as the diagnostic diamino acid, and arabinose and ribose as the major whole-cell sugars. The diagnostic phospholipids were phosphatidylethanolamine, phosphatidylcholine and phosphatidylglycerol. The predominant menaquinone was MK-9(H4). The major fatty acids were iso-C16 : 0, anteiso-C17 : 0, iso-C15 : 0 and anteiso-C15 : 0. On the basis of the evidence from this polyphasic study, a novel species, Saccharopolyspora halotolerans sp. nov., is proposed. The type strain of Saccharopolyspora halotolerans is TRM 45123T ( = CCTCC AA 2013006T = DSM 45990T).

Saccharopolyspora tripterygii sp. nov., an endophytic actinomycete isolated from the stem of Tripterygium hypoglaucum

An endophytic actinomycete, designated strain YIM 65359(T), was isolated from a surface-sterilized stem sample of Tripterygium hypoglaucum collected from Yunnan province, south-west China. The morphological and chemotaxonomic properties of the new isolate were consistent with those of members of the genus Saccharopolyspora. Analysis of 16S rRNA gene sequences revealed that the new isolate was most closely related to 'Saccharopolyspora endophytica' YIM 61095 (98.6 %), Saccharopolyspora flava AS4.1520(T) (97.6 %) and Saccharopolyspora spinosa DSM 44228(T) (97.0 %). The results of DNA-DNA hybridizations (57.5 %, 44.9 % and 48.5 %, respectively) with the above micro-organisms, in combination with differences in the biochemical and physiological characteristics, suggested that strain YIM 65359(T) should be classified as a novel species of the genus Saccharopolyspora. The name Saccharopolyspora tripterygii sp. nov. is proposed for this novel species, with YIM 65359(T) (=CCTCC AA 208062(T)=DSM 45269(T)) as the type strain.

Saccharopolyspora rosea sp. nov., isolated from a patient with bronchial carcinoma

The taxonomic status of a bacterium isolated from a patient with bronchial carcinoma was established using a polyphasic taxonomic approach. The strain had morphological and chemotaxonomic characteristics consistent with those of members of the genus Saccharopolyspora. The generic assignment was confirmed by comparative analysis of the 16S rRNA gene sequence, which showed that the strain constituted a distinct phyletic line, displaying 93.5-96.9 % sequence similarity with respect to members of the genus Saccharopolyspora. The isolate was distinguished from the type strains of recognized members of the genus Saccharopolyspora by means of various biochemical tests. The genotypic and phenotypic data obtained demonstrated that strain IMMIB L-1070(T) represents a novel species of the genus Saccharopolyspora, for which the name Saccharopolyspora rosea sp. nov. is proposed. The type strain is IMMIB L-1070(T) (=DSM 45226(T)=CCUG 56401(T)).