Actinoplanes liguriensis sp. nov. and Actinoplanes teichomyceticus sp. nov.

The taxonomic status of 'Actinoplanes liguriae' A/6353 and 'Actinoplanes teichomyceticus' AB8327 was established by using a polyphasic approach. Strains A/6353 and AB8327 form distinct phylogenetic lineages in the 16S rRNA gene tree of members of the genus Actinoplanes and are related moderately and closely to Actinoplanes rectilineatus and Actinoplanes cyaneus, respectively. Morphological, cultural and physiological properties indicated that strains A/6353 and AB8327 represent separate, novel species of the genus Actinoplanes, Actinoplanes liguriensis sp. nov. (type strain A/6353(T)=FH 2244(T)=DSM 43865(T)=ATCC 31048(T)=BCRC 12121(T)=CBS 355.75(T)=IMSNU 22127(T)=JCM 3250(T)=KCTC 9536(T)=KCC A-0250(T)=NBRC 13997(T)=NCIMB 12636(T)=NRRL B-16723(T)=SANK 62178(T)) and Actinoplanes teichomyceticus sp. nov. (type strain AB8327(T)=FH 2149(T)=DSM 43866(T)=ATCC 31121(T)=BCRC 12106(T)=FERM P-3462(T)=IMSNU 20043(T)=IMET 9254(T)=JCM 3252(T)=KCC A-0252(T)=KCTC 9543(T)=NBRC 13999(T)=NCIMB 12640(T)=NRRL B-16726(T)=SANK 60479(T)).

Amycolatopsis decaplanina sp. nov., a novel member of the genus with unusual morphology.

Strain DSM 44594T, which produces the glycopeptide antibiotic decaplanin, is a member of the genus Amycolatopsis based on 16S rRNA gene sequence analysis and chemotaxonomic properties. It is the first member of this genus that is reported to form pseudosporangia, which resemble those of members of the genus Kibdelosporangium. Phylogenetically, the novel taxon is related to Amycolatopsis orientalis, Amycolatopsis lurida, Amycolatopsis azurea, Amycolatopsis japonica and Amycolatopsis keratiniphila. Morphological, cultural and physiological properties, the production of a unique glycolipid and DNA-DNA similarity of <55% with phylogenetically related strains reveal that strain DSM 44594T represents a novel species of the genus, for which the name Amycolatopsis decaplanina sp. nov. (type strain, FH 1845T=DSM 44594T=NRRL B-24209T) is proposed.

Actinomadura namibiensis sp. nov.

Strain HAG 010767(T) was isolated from desert soil from Namibia during a screening programme. On the basis of analysis of 16S rDNA, the principal amino acid of the peptidoglycan, cell-wall sugars, fatty acids and polar lipids, it was possible to identify this strain as a member of the genus Actinomadura. Although DNA-DNA reassociation experiments revealed 72% DNA similarity between strain HAG 010767(T) and Actinomadura kijaniata DSM 43764(T), significant differences in the colour of the mycelium and physiological properties indicate that strain HAG 010767(T) represents a novel species of this genus, for which the name Actinomadura namibiensis sp. nov. is proposed. The type strain is strain HAG 010767(T) (= DSM 44197(T) = NRRL B-24153(T)).

Three new antibiotic producing species of the genus Amycolatopsis, Amycolatopsis balhimycina sp. nov., A. tolypomycina sp. nov., A. vancoresmycina sp. nov., and description of Amycolatopsis keratiniphila subsp. keratiniphila subsp. nov. and A. keratiniphila subsp. nogabecina subsp. nov.

Screening of Indian soils for strains producing antibiotics active against methicillin resistant staphylococci resulted in the isolation of the actinomycetes FH 1894T, ST 101170T, and FH 1893T, producing novel glycopeptide antibiotics and a polyenic compound, respectively. Studies of the cellular fatty acids and the absence of mycolic acids as well as the 16S rRNA gene sequence analysis of the producers indicated their membership to the genus Amycolatopsis. Comparison of genomic and metabolic properties of these strains with known species of this genus indicated that they represent new species for which the names Amycolatopsis balhimycina (type strain FH 1894T, DSM 44591T) and Amycolatopsis vancoresmycina (type strain ST 101170T, DSM 44592T) are proposed. The producer of the antibiotic Tolypomycin, strain IFO 14664T, representing the invalid species "Amycolatopsis tolypophorus", was also included in this investigation. As this strain was found to represent a valid species of the genus Amycolatopsis the name Amycolatopsis tolypomycina is proposed for this species, with the type strain IFO 14664T (DSM 44544T). The producer of the antibiotic Nogabecin, strain FH 1893T, was found to be closely related to the type strain of A. keratiniphila DSM 44409T which justifies the description of two subspecies of this species, A. keratiniphila subsp. keratiniphila DSM 44409T and A. keratiniphila subsp. nogabecina DSM 44586T.

Ustilipids, acylated beta-D-mannopyranosyl D-erythritols from Ustilago maydis and Geotrichum candidum.

Ustilago species produce an extracellular oil that shows activity in various pharmaceutical assays. We isolated several complexes of this heterogeneous glycolipid from cultures of Ustilago maydis DSM 11494 and Geotrichum candidum ST 002515, and determined the chemical structures of these new compounds, termed ustilipids, on the basis of NMR experiments, mass spectra, and fatty acid analyses. They all possess a 4-O-beta-D-mannopyranosyl D-erythritol basic framework, the configuration of which was confirmed, after initial solvolysis, by a single-crystal X-ray structure analysis. All the investigated ustilipids and related compounds are similarly constructed: the three hydroxy groups of the erythritol side chain are free in all cases, whereas the hydroxy groups of the mannose residue are for the most part acylated. Medium-chain fatty acids have for the first time been detected as components of glycolipids produced by Ustilaginales. While the 2-hydroxy group of the mannose residue is esterified with a C2-C8 carboxylate side chain, the 3-hydroxy group is in all cases esterified by a longer, C12-C20 fatty acid residue. The oxygen functionalities at the 4 and 6 positions are either acetylated or present as free hydroxy groups. Ustilipids antagonize dopamine D3 receptors in micromolar quantities; other members of this class of compounds have been found to possess an inhibitory action on the neurotensin receptor. The hemolytic activity of ustilipids is low.

Coniosetin, a novel tetramic acid antibiotic from Coniochaeta ellipsoidea DSM 13856.

The coprophilic ascomycete Coniochaeta ellipsoidea DSM 13856 forms the new antibiotic coniosetin (1) in surface cultures grown on a medium containing malt extract and oatmeal. The structure of the compound C25H35NO4, MW 413, was determined by 2D-NMR and mass spectrometric studies. Coniosetin belongs to the class of tetramic acids; it consists of a substituted aliphatic bicyclic ring system linked to a tetramic acid subunit through a carbonyl center. The absolute configuration was determined by measuring its circular dichroism spectrum and comparing the data with those of equisetin. Coniosetin has a pronounced antibacterial and antifungal action, inhibiting even multi drug-resistant strains of Staphylococcus aureus at a concentration of 0.3 microg/ml, though it is inactive against Gram-negative bacteria.

Cyclipostins, novel hormone-sensitive lipase inhibitors from Streptomyces sp. DSM 13381. II. Isolation, structure elucidation and biological properties.

Hormone-sensitive lipase (HSL) is a key enzyme of lipid metabolism and its control is therefore a target in the treatment of diabetes mellitus. Cultures of the Streptomyces species DSM 13381 have been shown to potently inhibit HSL. Ten inhibitors of HSL, termed cyclipostins, have been isolated from the mycelium of this microorganism and a further nine related compounds detected. Their structures were characterized by 2-D NMR experiments and by mass spectrometry and were found to comprise neutral cyclic enol phosphate esters with an additional y-lactone ring. On account of their ester-bound fatty alcohol side chain, the cyclipostins have physicochemical properties similar to those of triglycerides. The outstanding characteristic of the cyclipostins is their strong anti-HSL activity, with IC50 values in the nanomolar range.