Aspergetherins A-D, New Chlorinated Biphenyls with anti-MRSA Activity from the Marine Sponge Symbiotic Fungus Aspergillus terreus 164018.

Aspergetherins A-D (1-4), four new chlorinated biphenyls, were isolated from the rice fermentation of a marine sponge symbiotic fungus Aspergillus terreus 164018, along with seven known biphenyl derivatives (5-11). The structures of four new compounds were determined by a comprehensive analysis of the spectroscopic data, including HR-ESI-MS and 2D NMR data. All 11 isolates were evaluated for their anti-bacterial activity against two strains of methicillin-resistant Staphylococcus aureus (MRSA). Among them, compounds 1, 3, 8 and 10 showed anti-MRSA activity with MIC values of 1.0-128 µg/mL. Preliminary structure-activity relationship analysis unveiled that both chlorinated substitution and esterification of 2-carboxylic acid could impact the antibacterial activity of biphenyls.

Flavipesides A-C, PKS-NRPS Hybrids as Pancreatic Lipase Inhibitors from a Marine Sponge Symbiotic Fungus Aspergillus flavipes 164013.

Three unusual chlorinated PKS-NRPS hybrid metabolites, flavipesides A-C (1-3), were isolated from a strain of marine sponge symbiotic fungus Aspergillus flavipes 164013. Their structures were determined by spectroscopic data analysis, and absolute configurations were assigned by single-crystal X-ray diffraction with ECD spectral analysis. Flavipesides A-C showed potent pancreatic lipase (PL) inhibitory activity with IC50 values of 0.07-0.23 µM.

Actinomadura craniellae sp. nov., isolated from a marine sponge in the South China Sea.

A novel marine actinomycete, designated LHW63021T, was isolated from a marine sponge, genus Craniella, collected in the South China Sea. A polyphasic approach was applied to characterize the taxonomic position of this strain. The strain was found to have scarce aerial mycelia that differentiated into spore chains. The cell-wall hydrolysates contained meso-diaminopimelic acid as the diagnostic diamino acid. Glucose, galactose, mannose and madurose were found in the whole-cell hydrolysates. The dominant polar lipids were phosphatidylinositol and diphosphatidylglycerol. MK-9(H6) and MK-9(H8) were the predominant menaquinones. The major fatty acids were iso-C16 : 0, iso-C18 : 0, 10-methyl C17 : 0 and C18 : 1 ω9c. The DNA G+C content based on the draft genome sequence was 72.0 mol%. 16S rRNA gene sequence analysis indicated that strain LHW63021T was a member of the genus Actinomadura and had the highest similarity to Actinomadura echinospora DSM 43163T (97.3 %). Phylogenetic trees supported their close relationship. The average nucleotide identity and digital DNA-DNA hybridization values between the whole genome sequences of strain LHW63021T and A. echinospora DSM 43163T were 79.13 and 23.20 %, respectively. The evidence from the polyphasic study shows that strain LHW63021T represents a novel species of the genus Actinomadura, for which the name Actinomadura craniellae sp. nov. is proposed. The type strain is LHW63021T (=DSM 106125T=CCTCC AA 2018015T).

Micromonospora craniellae sp. nov., isolated from a marine sponge, and reclassification of Jishengella endophytica as Micromonospora endophytica comb. nov.

A novel marine actinomycete, designated LHW63014T, isolated from a marine sponge, Craniella species, collected in the South China Sea, was examined using a polyphasic approach. The 16S rRNA gene sequence of strain LHW63014T showed highest similarities to Jishengella endophytica 202201T (98.9 %), Micromonospora olivasterospora DSM 43868T (98.7 %), Micromonospora maris AB-18-032T (98.6 %) and Micromonospora gifhornensis DSM 44337T (98.6 %). Phylogenetic analyses of the family Micromonosporaceae based on the 16S rRNA and gyrB gene sequences indicated that strain LHW63014T and J. endophytica 202201T located within the genus Micromonospora. Morphological and chemotaxonomic characteristics confirmed their affiliation to the genus Micromonospora. Based on phenotypic characteristics, phylogenetic data and digital DNA-DNA hybridization results, strain LHW63014T could be distinguished from its closest taxa, representing a novel species of the genus Micromonospora, for which the name Micromonospora craniellae sp. nov., is proposed, with the type strain LHW63014T (=DSM 106193T=CCTCC AA 2018012T). It is also proposed that J. endophytica be transferred to genus Micromonospora as Micromonospora endophytica comb. nov. (type strain 202201T =CGMCC 4.5597T=DSM 45430T).

Spongiactinospora rosea gen. nov., sp. nov., a new member of the family Streptosporangiaceae.

A novel aerobic, spore-forming, marine actinomycete, designated strain LHW63015T, was isolated from a Craniella marine sponge collected in the South China Sea. The strain formed extensively branched substrate and aerial mycelia which carried long and crooked spore chains composed of ridged spores and spherical pseudosporangia. Strain LHW63015T contained meso-diaminopimelic acid as the diagnostic diamino acid. Glucose, ribose, mannose, galactose and madurose occured in whole-cell hydrolysates. The predominant polar lipids were hydroxyl-phosphatidylethanolamine, phosphoglycolipid and ninhydrin-positive phosphoglycolipid. MK-10(H4) and MK-10(H6) were the predominant menaquinones. The major fatty acids were 10-methyl C17 : 0 and C17 : 1ω8c. The G+C content of the genomic DNA was 70.8 mol%. In phylogenetic analysis based on 16S rRNA gene sequences, strain LHW63015T fell within the family Streptosporangiaceae and formed a distinct monophyletic lineage adjacent to the genus Sphaerisporangium, and shared the highest 16S rRNA gene sequence similarity of 96.2 % with Sphaerisporangium album YIM 48782T. On the basis of the polyphasic evidence, a novel genus and species of the family Streptosporangiaceae, for which the name Spongiactinospora rosea gen. nov., sp. nov., is proposed, with the type strain LHW63015T (=DSM 106635T=CCTCC AA 2018019T).