Saccharopolyspora mangrovi sp. nov., a novel mangrove soil actinobacterium with distinct metabolic potential revealed by comparative genomic analysis

A novel mangrove soil-derived actinomycete, strain S2-29T, was found to be most closely related to Saccharopolyspora karakumensis 5K548T based on 16 S rRNA sequence (99.24% similarity) and genomic phylogenetic analyses. However, significant divergence in digital DNA-DNA hybridization, average nucleotide identity, and unique biosynthetic gene cluster possession distinguished S2-29T as a distinct Saccharopolyspora species. Pan genome evaluation revealed exceptional genomic flexibility in genus Saccharopolyspora, with > 95% accessory genome content. Strain S2-29T harbored 718 unique genes, largely implicated in energetic metabolisms, indicating different metabolic capacities from its close relatives. Several uncharacterized biosynthetic gene clusters in strain S2-29T highlighted the strain's untapped capacity to produce novel functional compounds with potential biotechnological applications. Designation as novel species Saccharopolyspora mangrovi sp. nov. (type strain S2-29T = JCM 34,548T = CGMCC 4.7716T) was warranted, expanding the known Saccharopolyspora diversity and ecology. The discovery of this mangrove-adapted strain advances understanding of the genus while highlighting an untapped source of chemical diversity.

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 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.