Actinomadura rubteroloni sp. nov. and Actinomadura macrotermitis sp. nov., isolated from the gut of the fungus growing-termite Macrotermes natalensis

The taxonomic positions of two novel aerobic, Gram-positive actinobacteria, designated strains RB29$^{T}$ and RB68T, were determined using a polyphasic approach. Based on 16S rRNA gene sequence analysis, the closest phylogenetic neighbours of RB29$^{T}$ were identified as Actinomadura rayongensis DSM 102126$^{T}$ (99.2 % similarity) and Actinomadura atramentaria DSM 43919$^{T}$ (98.7 %), and for strain RB68$^{T}$ was Actinomadura hibisca DSM 44148$^{T}$ (98.3 %). Digital DNA–DNA hybridization (dDDH) between RB29$^{T}$ and its closest phylogenetic neighbours, A. rayongensis DSM 102126$^{T}$ and A. atramentaria DSM 43919$^{T}$, resulted in similarity values of 53.2 % (50.6–55.9 %) and 26.4 % (24.1–28.9 %), respectively. Additionally, the average nucleotide identity (ANI) was 93.2 % (94.0 %) for A. rayongensis DSM 102126$^{T}$ and 82.3 % (78.9 %) for A. atramentaria DSM 43919$^{T}$. dDDH analysis between strain RB68$^{T}$ and A. hibisca DSM 44148$^{T}$ gave a similarity value of 24.5 % (22.2–27.0 %). Both strains, RB29$^{T}$ and RB68$^{T}$, revealed morphological characteristics and chemotaxonomic features typical for the genus Actinomadura, such as the presence of meso-diaminopimelic acid in the cell wall, galactose and glucose as major sugar components within whole-cell hydrolysates and the absence of mycolic acids. The major phospholipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannoside. Predominant menaquinones were MK-9(H$_{6}$) and MK-9(H$_{8}$) for RB29$^{T}$ and MK-9(H$_{4}$) and MK-9(H$_{6}$) for RB68T. The main fatty acids were identified as 10-methyloctadecanoic acid (10-methyl C$_{18:0}$), 14-methylpentadecanoic acid (iso-C$_{16:0}$), hexadecanoic acid (C$_{16:0}$) and cis-9-octadecanoic acid (C$_{18:1}$ ω9c). Here, we propose two novel species of the genus Actinomadura: Actinomadura rubteroloni sp. nov. with the type strain RB29$^{T}$ (=CCUG 72668$^{T}$=NRRL B-65537$^{T}$) and Actinomadura macrotermitis sp. nov. with the type strain RB68$^{T}$ (=CCUG 72669$^{T}$=NRRL B-65538$^{T}$)

Streptomyces smaragdinus sp. nov., isolated from the gut of the fungus growing-termite Macrotermes natalensis

The taxonomic position of a novel aerobic, Grampositive actinobacteria, designated strain RB5(T), was determined using a poly phasic approach. The strain, isolated from the gut of the fungusfarming termite Macrotermes natalensis, showed morphological, physiological and chemotaxonomic properties typical of the genus Streptomyces. Based on 16S rRNA gene sequence analysis, the closest phylogenetic neighbour of RB5(T) was Streptomyces polyrhachis DSM 42102(T) (98.87 %). DNA-DNA hybridization experiments between strain RB5(T) and S. polyrhachis DSM 42102(T) resulted in a value of 27.4 % (26.8 %). The cell wall of strain RB5(T) contained iota iota diaminopimelic acid as the diagnostic amino acid. Mycolic acids and diagnostic sugars in whole cell hydrolysates were not detected. The strain produced the following major phospholipids: diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositolmannoside and phosphatidylserine. The menaquinone profile showed hexaand octahydrogenated menaquinones containing nine isoprene units [MK-9(H-6) and MK-9(H-8)]. The strain exhibited a fatty acid profile containing the following major fatty acids: 12methyltridecanoic acid (isoC(14:0)) 12-methyltetradecanoic acid (anteiso-C-15:0), 13-methyltetradecanoic acid (isoC(15:0)) and 14-methylpentadecanoic acid (isoC(16:0)). Here, we propose a novel species of the genus Streptomyces - Streptomyces smaragdinus with the type strain RB5(T) (=VKM Ac-2839(T)=NRRL B65539(T))

Polytetrafluoroethylene coating fragments during neuroendovascular therapy:An analysis of two damaged microguidewires

Cerebral polymer coating embolism from intravascular devices represents a potentially serious complication to endovascular therapy (EVT). We report two cases of neuroendovascular treatment where filamentous polymer fragments were noted possibly due to damage of the surface coating during manipulation and backloading of microguidewires. As the exact origin of the debris was initially not known, microguidewires and fragments were examined with light microscopy, stereomicroscopy, scanning electron microscopy and attenuated-total-reflection Fourier transform infrared spectroscopy. Fragments consisted of polytetrafluoroethylene and silicone oil stemming from the proximal shaft of a standard microguidewire. To our knowledge, this is the first report of polytetrafluoroethylene coating fragments created during EVT. Future studies should assess the mechanism of polymer coating delamination and its potential consequences during EVT including inadvertent fragment migration into the cerebral circulation

The Coprophilous Mushroom Coprinus radians Secretes a Haloperoxidase That Catalyzes Aromatic Peroxygenation▿

Coprophilous and litter-decomposing species (26 strains) of the genus Coprinus were screened for peroxidase activities by using selective agar plate tests and complex media based on soybean meal. Two species, Coprinus radians and C. verticillatus, were found to produce peroxidases, which oxidized aryl alcohols to the corresponding aldehydes at pH 7 (a reaction that is typical for heme-thiolate haloperoxidases). The peroxidase of Coprinus radians was purified to homogeneity and characterized. Three fractions of the enzyme, CrP I, CrP II, and CrP III, with molecular masses of 43 to 45 kDa as well as isoelectric points between 3.8 and 4.2, were identified after purification by anion-exchange and size exclusion chromatography. The optimum pH of the major fraction (CrP II) for the oxidation of aryl alcohols was around 7, and an H2O2 concentration of 0.7 mM was most suitable regarding enzyme activity and stability. The apparent Km values for ABTS [2,2′-azinobis(3-ethylbenzthiazolinesulfonic acid)], 2,6-dimethoxyphenol, benzyl alcohol, veratryl alcohol, and H2O2 were 49, 342, 635, 88, and 1,201 μM, respectively. The N terminus of CrP II showed 29% and 19% sequence identity to Agrocybe aegerita peroxidase (AaP) and chloroperoxidase, respectively. The UV-visible spectrum of CrP II was highly similar to that of resting-state cytochrome P450 enzymes, with the Soret band at 422 nm and additional maxima at 359, 542, and 571 nm. The reduced carbon monoxide complex showed an absorption maximum at 446 nm, which is characteristic of heme-thiolate proteins. CrP brominated phenol to 2- and 4-bromophenols and selectively hydroxylated naphthalene to 1-naphthol. Hence, after AaP, CrP is the second extracellular haloperoxidase-peroxygenase described so far. The ability to extracellularly hydroxylate aromatic compounds seems to be the key catalytic property of CrP and may be of general significance for the biotransformation of poorly available aromatic substances, such as lignin, humus, and organopollutants in soil litter and dung environments. Furthermore, aromatic peroxygenation is a promising target of biotechnological studies

Fridamycin A, a Microbial Natural Product, Stimulates Glucose Uptake without Inducing Adipogenesis

Type 2 diabetes is a complex, heterogeneous, and polygenic disease. Currently, available drugs for treating type 2 diabetes predominantly include sulfonylureas, α-glucosidase inhibitors, and biguanides. However, long-term treatment with these therapeutic drugs is often accompanied by undesirable side effects, which have driven interest in the development of more effective and safer antidiabetic agents. To address the urgent need for new chemical solutions, we focused on the analysis of structurally novel and/or biologically new metabolites produced by insect-associated microbes as they have recently been recognized as a rich source of natural products. Comparative LC/MS-based analysis of Actinomadura sp. RB99, isolated from a fungus-growing termite, led to the identification of the type II polyketide synthase-derived fridamycin A. The structure of fridamycin A was confirmed by 1H NMR data and LC/MS analysis. The natural microbial product, fridamycin A, was examined for its antidiabetic properties in 3T3-L1 adipocytes, which demonstrated that fridamycin A induced glucose uptake in 3T3-L1 cells by activating the AMP-activated protein kinase (AMPK) signaling pathway but did not affect adipocyte differentiation, suggesting that the glucose uptake took place through activation of the AMPK signaling pathway without inducing adipogenesis. Our results suggest that fridamycin A has potential to induce fewer side effects such as weight gain compared to rosiglitazone, a commonly used antidiabetic drug, and that fridamycin A could be a novel potential therapeutic candidate for the management of type 2 diabetes