RESUMEN
Niemann-Pick type C (NP-C) disease is a rare lysosomal storage disease caused by mutations in NPC1 (95% cases) or NPC2 (5% cases). These proteins function together in cholesterol egress from the lysosome, whereby upon mutation, cholesterol and other lipids accumulate causing major pathologies. However, it is not fully understood how cholesterol is transported from NPC1 residing at the lysosomal membrane to the endoplasmic reticulum (ER) and plasma membrane. The yeast ortholog of NPC1, Niemann-Pick type C-related protein-1 (Ncr1), functions similarly to NPC1; when transfected into a mammalian cell lacking NPC1, Ncr1 rescues the diagnostic hallmarks of cholesterol and sphingolipid accumulation. Here, we aimed to identify and characterize protein-protein interactions (PPIs) with the yeast Ncr1 protein. A genome-wide split-ubiquitin membrane yeast two-hybrid (MYTH) protein interaction screen identified 11 ER membrane-localized, full-length proteins interacting with Ncr1 at the lysosomal/vacuolar membrane. These highlight the importance of ER-vacuole membrane interface and include PPIs with the Cyb5/Cbr1 electron transfer system, the ceramide synthase complex, and the Sec61/Sbh1 protein translocation complex. These PPIs were not detected in a sterol auxotrophy condition and thus depend on normal sterol metabolism. To provide biological context for the Ncr1-Cyb5 PPI, a yeast strain lacking this PPI (via gene deletions) exhibited altered levels of sterols and sphingolipids including increased levels of glucosylceramide that mimic NP-C disease. Overall, the results herein provide new physical and genetic interaction models to further use the yeast model of NP-C disease to better understand human NP-C disease.
Asunto(s)
Enfermedad de Niemann-Pick Tipo C , Saccharomyces cerevisiae , Animales , Humanos , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Enfermedad de Niemann-Pick Tipo C/tratamiento farmacológico , Enfermedad de Niemann-Pick Tipo C/genética , Enfermedad de Niemann-Pick Tipo C/metabolismo , Receptor 1 Gatillante de la Citotoxidad Natural/metabolismo , Proteínas/genética , Colesterol , Esteroles/metabolismo , MamíferosRESUMEN
Eicosapentaenoic acid (EPA) is an essential omega-3 polyunsaturated fatty acid that plays a critical role in marine life. It is present in several marine animals, including fish, but the primary producers of EPA are phytoplankton and specific marine bacteria. Although most of the EPA present in marine animals come from phytoplankton, the bacterial input into the marine EPA food web is still unknown. The labelling of EPA within a bacterial strain could be a viable strategy to help revealing this contribution. In this work, Shewanella marinintestina IRL 567, a marine bacterium isolated from fish guts and known to produce EPA, was labelled with the stable isotope 13C at small (250-mL shake flask), bench (2.5-L shake flask), and pilot scale (50-L stirred tank bioreactor). Growing the bacterium with 13C-acetate in the culture medium demonstrated that EPA was de-novo synthesized utilizing acetate as precursor. 13C incorporation into the EPA molecule resulted in values as high as 95.5% of the synthesized EPA being labelled in small scale, 95.9% in bench scale and 91.5% in pilot scale. This simple method to label EPA proved to be effective and therefore it could be a valuable tool to follow the fate of bacterial EPA into higher trophic levels.
Asunto(s)
Ácido Eicosapentaenoico , Shewanella , Animales , Ácido Eicosapentaenoico/metabolismo , Shewanella/metabolismo , Peces/microbiología , Isótopos/metabolismoRESUMEN
N-acylethanolamines (NAE, also called ethanolamides) are significant lipid signaling molecules with anti-inflammatory, pain-relieving, cell-protective, and anticancer properties. Here, we present the use of a hitherto unreported group of Δ3-NAE and also some Δ4- and Δ5-NAE, in in vitro and in vivo assays to gain a better understanding of their structure-bioactivity relationships. We have developed an efficient synthetic method to rapidly produce novel unlabeled and 13 C-labeled Δ3-NAE (NAE-18:5n-3, NAE-18:4n-6) and Δ4-NAE (NAE-22:5n-6). The new NAE with shorter carbon backbone structures confers greater neuroprotection than their longer carbon backbone counterparts, including anandamide (Δ5-NAE-20:4n-6) in a focal ischemia mouse model of stroke. This study highlights structure-dependent protective effects of new NAE following focal ischemia, in which some of the new NAE, administered intranasally, lead to significantly reduced infarct volume and improved recovery of limb use. The relative affinity of the new NAE toward cannabinoid receptors was assessed against anandamide, NAE-22:6n-3 and NAE-20:5n-3, which are known cannabinoid receptor ligands with high-binding constants. Among the newly synthesized NAE, Δ4-NAE-22:5n-6 shows the greatest relative affinity to cannabinoid receptors hCB1 and hCB2 , and inhibition of cyclic adenosine monophosphate activity through hCB2 compared to anandamide.
Asunto(s)
Neuroprotección , Accidente Cerebrovascular , Animales , Etanolaminas , Ratones , Receptores de CannabinoidesRESUMEN
Knowledge of factors influencing the levels of 4-alkyl branched-chain fatty acid (vBCFA), and consequently the "sheepy flavor" intensity of New Zealand sheep milk, is currently limited. In this study, we investigated the effects of 2 contrasting farming systems (fully housed/mid-lactation or pasture-grazed/late lactation) on the levels of vBCFA in sheep milk on a commercial farm in the North Island of New Zealand. Fully housed/mid-lactation ewes were housed 24 h/d and fed a total mixed ration. Pasture-grazed/late-lactation ewes were grazed 24 h/d and offered approximately 40% supplements because of poor pasture growth resulting from dry and hot climatic conditions. Any effects of genetics, age, lactation stage, feed composition, lambing date, or the environment in the housing barn or outdoors were confounded. The results obtained in this study were descriptive rather than definitive, because of the limitations of the experimental design. Levels of 4-methyloctanoic acid and 4-methylnonanoic acid in milk from fully housed/mid-lactation ewes increased during the trial period, but remained low in milk from pasture-grazed/late-lactation ewes. Levels of 4-ethyloctanoic acid in milk from the 2 groups of ewes were comparable throughout the trial. Increases in levels of 4-methyloctanoic acid and 4-methylnonanoic acid in sheep milk were associated with lactation stage and the proportion of lucerne silage fed to ewes. The level of free-form 4-ethyloctanoic acid was positively correlated with the proportion of soy meal in the diet and negatively correlated with the proportion of barley. Milk from fully housed/mid-lactation ewes had a higher flavor values than milk from pasture-grazed/late-lactation ewes because of its higher total amounts of vBCFA.
Asunto(s)
Alimentación Animal , Industria Lechera/métodos , Ácidos Grasos/análisis , Leche/química , Ovinos , Alimentación Animal/análisis , Animales , Dieta/veterinaria , Suplementos Dietéticos , Femenino , Lactancia , Nueva Zelanda , EnsilajeRESUMEN
Three thermophilic Nanoarchaeota-Crenarchaeota symbiotic systems have been described. We obtained another stable anaerobic enrichment culture at 80°C, pH 6.0 from a New Zealand hot spring. The nanoarchaeote (Ncl-1) and its host (NZ3T) were isolated in co-culture and their genomes assembled. The small (â¼200nm) flagellated cocci were often attached to larger cocci. Based on 16S rRNA gene similarity (88.4%) and average amino acid identity (52%), Ncl-1 is closely related to Candidatus Nanopusillus acidilobi. Their genomes both encode for archaeal flagella and partial glycolysis and gluconeogenesis pathways, but lack ATP synthase genes. Like Nanoarchaeum equitans, Ncl-1 has a CRISPR-Cas system. Ncl-1 also relies on its crenarchaeotal host for most of its biosynthetic needs. The host NZ3T was isolated and grows on proteinaceous substrates but not on sugars, alcohols, or fatty acids. NZ3T requires thiosulfate and grows best at 82°C, pH 6.0. NZ3T is most closely related to the Desulfurococcaceae, Ignisphaera aggregans (â¼92% 16S rRNA gene sequence similarity, 45% AAI). Based on phylogenetic, physiological and genomic data, Ncl-1 and NZ3T represent novel genera in the Nanoarchaeota and the Desulfurococcaceae, respectively, with the proposed names Candidatus Nanoclepta minutus and Zestosphaera tikiterensis gen. nov., sp. nov., type strain NZ3T (=DSMZ 107634T=OCM 1213T).
Asunto(s)
Desulfurococcaceae/clasificación , Manantiales de Aguas Termales/microbiología , Filogenia , Simbiosis , Desulfurococcaceae/genética , Genoma Arqueal , Nueva Zelanda , ARN Ribosómico 16S/genéticaRESUMEN
Edible brown algae have attracted interest as a source of beneficial allenic carotenoid fucoxanthin, and glyco- and phospholipids enriched in polyunsaturated fatty acids. Unlike green algae, brown algae contain no or little phosphatidylserine, possessing an unusual aminophospholipid, phosphatidyl-O-[N-(2-hydroxyethyl) glycine], PHEG, instead. When our routinely used technique of 31P-NMR analysis of phospholipids was applied to the samples of edible New Zealand brown algae, a number of signals corresponding to unidentified phosphorus-containing compounds were observed in total lipids. NI (negative ion) ESI QToF MS spectra confirmed the presence of more familiar phospholipids, and also suggested the presence of PHEG or its isomers. The structure of PHEG was confirmed by comparison with a synthetic standard. An unusual MS fragmentation pattern that was also observed prompted us to synthesise a number of possible candidates, and was found to follow that of phosphatidylhydroxyethyl methylcarbamate, likely an extraction artefact. An unexpected outcome was the finding of ceramidephosphoinositol that has not been reported previously as occurring in brown algae. An uncommon arsenic-containing phospholipid has also been observed and quantified, and its TLC behaviour studied, along with that of the newly synthesised lipids.
Asunto(s)
Phaeophyceae/química , Fosfolípidos/análisis , Espectroscopía de Resonancia Magnética , Estructura Molecular , Nueva Zelanda , Fosfolípidos/químicaRESUMEN
Niemann-Pick type C (NP-C) disease is a fatal genetic lipidosis for which there is no Food and Drug Administration (FDA)-approved therapy. Vorinostat, an FDA-approved inhibitor of histone deacetylases, ameliorates lysosomal lipid accumulation in cultured NP-C patient fibroblasts. To assess the therapeutic potential of histone deacetylase inhibition, we pursued these in vitro observations in two murine models of NP-C disease. Npc1nmf164 mice, which express a missense mutation in the Npc1 gene, were treated intraperitoneally, from weaning, with the maximum tolerated dose of vorinostat (150 mg/kg, 5 days/week). Disease progression was measured via gene expression, liver function and pathology, serum and tissue lipid levels, body weight, and life span. Transcriptome analyses of treated livers indicated multiple changes consistent with reversal of liver dysfunction that typifies NP-C disease. Significant improvements in liver pathology and function were achieved by this treatment regimen; however, NPC1 protein maturation and levels, disease progression, weight loss, and animal morbidity were not detectably altered. Vorinostat concentrations were >200 µm in the plasma compartment of treated animals but were almost 100-fold lower in brain tissue. Apolipoprotein B metabolism and the expression of key components of lipid homeostasis in primary hepatocytes from null (Npc1-/-) and missense (Npc1nmf164 ) mutant mice were altered by vorinostat treatment, consistent with a response by these cells independent of the status of the Npc1 locus. These results suggest that HDAC inhibitors have utility to treat visceral NP-C disease. However, it is clear that improved blood-brain barrier penetration will be required to alleviate the neurological symptoms of human NP-C disease.
Asunto(s)
Inhibidores de Histona Desacetilasas/uso terapéutico , Ácidos Hidroxámicos/uso terapéutico , Hígado/efectos de los fármacos , Hígado/fisiopatología , Enfermedad de Niemann-Pick Tipo C/tratamiento farmacológico , Enfermedad de Niemann-Pick Tipo C/genética , Proteínas/genética , Animales , Apolipoproteínas B/metabolismo , Células Cultivadas , Colesterol/genética , Colesterol/metabolismo , Modelos Animales de Enfermedad , Inhibidores de Histona Desacetilasas/farmacocinética , Homeostasis/efectos de los fármacos , Humanos , Ácidos Hidroxámicos/farmacocinética , Péptidos y Proteínas de Señalización Intracelular , Hígado/metabolismo , Hígado/patología , Ratones , Ratones Endogámicos C57BL , Mutación Missense , Proteína Niemann-Pick C1 , Enfermedad de Niemann-Pick Tipo C/patología , Enfermedad de Niemann-Pick Tipo C/fisiopatología , Proteínas/metabolismo , Transcriptoma/efectos de los fármacos , VorinostatRESUMEN
1,2-Diol based phospholipids are a well-known feature of bacteria from the class Thermomicrobia. Since these bacteria contain only lipids with an alkyldiol-1-phosphate backbone instead of sn-glycero-3-phosphate, it is important to elucidate the stereochemistry of the 1,2-diols. We have studied the absolute stereochemistry of long-chain 1,2-diols isolated from Thermorudis pharmacophila (formerly known as Thermomicrobia sp. WKT50.2) by nuclear magnetic resonance (NMR) using α-methoxyphenylacetic acid (MPA). Low-temperature (-60 °C) NMR of bis-(R)-MPA ester showed (R) stereochemistry of the 1,2-diols. This is the first report concerning the stereochemistry of natural 1,2-diols, which replace the glyceride moiety in phospholipids. The (R) stereochemistry of the diols is expected as it is the same configuration as for the common bacterial lipid backbone-sn-glycero-3-phosphate. This is the first application of low-temperature NMR of a single MPA derivative for assignment of stereochemistry of natural 1,2-diols. The results were confirmed by the comparison of NMR data with bis-(R)-MPA ester of (R) and rac-1,2-octanediol.
Asunto(s)
Alcoholes/química , Chloroflexi/química , Fosfolípidos/química , Espectroscopía de Resonancia Magnética , Conformación Molecular , EstereoisomerismoRESUMEN
An aerobic, thermophilic and cellulolytic bacterium, designated strain WKT50.2T, was isolated from geothermal soil at Waikite, New Zealand. Strain WKT50.2T grew at 53-76 °C and at pH 5.9-8.2. The DNA G+C content was 58.4âmol%. The major fatty acids were 12-methyl C18 : 0 and C18 : 0. Polar lipids were all linked to long-chain 1,2-diols, and comprised 2-acylalkyldiol-1-O-phosphoinositol (diolPI), 2-acylalkyldiol-1-O-phosphoacylmannoside (diolP-acylMan), 2-acylalkyldiol-1-O-phosphoinositol acylmannoside (diolPI-acylMan) and 2-acylalkyldiol-1-O-phosphoinositol mannoside (diolPI-Man). Strain WKT50.2T utilized a range of cellulosic substrates, alcohols and organic acids for growth, but was unable to utilize monosaccharides. Robust growth of WKT50.2T was observed on protein derivatives. WKT50.2T was sensitive to ampicillin, chloramphenicol, kanamycin, neomycin, polymyxin B, streptomycin and vancomycin. Metronidazole, lasalocid A and trimethoprim stimulated growth. Phylogenetic analysis of 16S rRNA gene sequences showed that WKT50.2T belonged to the class Thermomicrobia within the phylum Chloroflexi, and was most closely related to Thermorudis peleae KI4T (99.6% similarity). DNA-DNA hybridization between WKT50.2T and Thermorudis peleae DSM 27169T was 18.0%. Physiological and biochemical tests confirmed the phenotypic and genotypic differentiation of strain WKT50.2T from Thermorudis peleae KI4T and other members of the Thermomicrobia. On the basis of its phylogenetic position and phenotypic characteristics, we propose that strain WKT50.2T represents a novel species, for which the name Thermorudis pharmacophila sp. nov. is proposed, with the type strain WKT50.2T ( = DSM 26011T = ICMP 20042T). Emended descriptions of Thermomicrobium roseum, Thermomicrobium carboxidum, Thermorudis peleae and Sphaerobacter thermophilus are also proposed, and include the description of a novel respiratory quinone, MK-8 2,3-epoxide (23%), in Thermomicrobium roseum.
Asunto(s)
Chloroflexi/clasificación , Filogenia , Microbiología del Suelo , Técnicas de Tipificación Bacteriana , Composición de Base , Chloroflexi/genética , Chloroflexi/aislamiento & purificación , ADN Bacteriano/genética , Ácidos Grasos/química , Manantiales de Aguas Termales , Calor , Datos de Secuencia Molecular , Nueva Zelanda , Hibridación de Ácido Nucleico , Fosfolípidos/química , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Vitamina K 2/análogos & derivados , Vitamina K 2/químicaRESUMEN
A high-efficiency, convenient, and reliable method for the separation of structurally similar triacylglycerols is detailed and applied in the quantitative analysis of 1,3-dioleoyl-2-palmitoylglycerol (OPO) in infant formulas and OPO oils. OPO is an important lipid component in "humanized" infant formula. A fast preparative isolation of an OPO-containing fraction from the crude complex mixture, by nonaqueous reversed phase HPLC, followed by Ag(+)-HPLC with detection at 205 nm allowed fine separation and detection of the desired fraction. OPO was quantitated independently of its regioisomer 1,2-dioleoyl-3-palmitoylglycerol (OOP) and isomers of stearoyl-linoleoyl-palmitoyl glycerol that might be present in infant formulas. For samples with low OPO content, an evaporative light-scattering detector (ELSD) was more preferable than UV detection, with a calculated LOD of 0.1 µg of OPO injected and LOQ of 0.3 µg. The method, which showed high reproducibility (RSD < 5%), was suitable for both high OPO content oils and low OPO products such as unenriched infant formula. A number of possible interference issues were considered and dealt with.
Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Fórmulas Infantiles/química , Palmitatos/análisis , Aceites de Plantas/química , Triglicéridos/análisis , Palmitatos/aislamiento & purificación , Sensibilidad y Especificidad , Triglicéridos/aislamiento & purificaciónRESUMEN
A novel bacterial strain, NGM72.4(T), was isolated from a hot spring in the Ngatamariki geothermal field, New Zealand. Phylogenetic analysis based on 16S rRNA gene sequences grouped it into the phylum Verrucomicrobia and class level group 3 (also known as OPB35 soil group). NGM72.4(T) stained Gram-negative, and was catalase- and oxidase-positive. Cells were small cocci, 0.5-0.8 µm in diameter, which were motile by means of single flagella. Transmission electron micrograph (TEM) imaging showed an unusual pirellulosome-like intracytoplasmic membrane. The peptidoglycan content was very small with only trace levels of diaminopimelic acid detected. No peptidoglycan structure was visible in TEM imaging. The predominant isoprenoid quinone was MK-7 (92%). The major fatty acids (>15%) were C(16â:â0), anteiso-C(15â:â0), iso-C(16â:â0) and anteiso-C(17â:â0). Major phospholipids were phosphatidylethanolamine (PE), phosphatidylmonomethylethanolamine (PMME) and cardiolipin (CL), and a novel analogous series of phospholipids where diacylglycerol was replaced with diacylserinol (sPE, sPMME, sCL). The DNA G+C content was 65.6 mol%. Cells displayed an oxidative chemoheterotrophic metabolism. NGM72.4(T) is a strictly aerobic thermophile (growth optimum 60-65 °C), has a slightly alkaliphilic pH growth optimum (optimum pH 8.1-8.4) and has a NaCl tolerance of up to 8 g l(-1). Colonies were small, circular and pigmented pale pink. The distinct phylogenetic position and phenotypic traits of strain NGM72.4(T) distinguish it from all other described species of the phylum Verrucomicrobia and, therefore, it is considered to represent a novel species in a new genus for which we propose the name Limisphaera ngatamarikiensis gen. nov., sp. nov. The type strain is NGM72.4(T) (â=âICMP 20182(T)â=âDSM 27329(T)).
Asunto(s)
Manantiales de Aguas Termales/microbiología , Filogenia , Verrucomicrobia/clasificación , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Grasos/química , Datos de Secuencia Molecular , Nueva Zelanda , Peptidoglicano/química , Fosfolípidos/química , Pigmentación , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Verrucomicrobia/genética , Verrucomicrobia/aislamiento & purificación , Vitamina K 2/análogos & derivados , Vitamina K 2/químicaRESUMEN
Polar lipids of bacteria from the class Thermomicrobia are known to contain long-chain 1,2-diols instead of glycerol, although the nature of polar head groups has not been investigated. We have studied phospholipid classes of two species from the class Thermomicrobia-Sphaerobacter thermophilus and Thermomicrobia sp. WKT50.2. TLC and (31)P-NMR analysis of polar lipids revealed that both S. thermophilus and Thermomicrobia sp. WKT50.2 contain the same set of four major phospholipid classes. Structures of the novel phospholipids in S. thermophilus were established as 2-acylalkyldiol-1-O-phosphoinositol, 2-acylalkyldiol-1-O-phosphoinositol mannoside, 2-acylalkyldiol-1-O-phospho-acylmannoside, and 2-acylalkyldiol-1-O-phosphoinositol acylmannoside. To our knowledge, this is the first report of a phospholipid with a mannose directly bound to the phosphate. We also analyzed fatty acids and long-chain 1,2-diols of S. thermophilus and Thermomicrobia sp. WKT50.2 and compared our data with available information for T. roseum. All species share a similar set of fatty acids, with 12-Me 18:0 being the major fatty acid. The major diol in S. thermophilus was identified as 13-Me 19:0 (66.2 %). The 21:0 diol was the major component both in Thermomicrobia sp. WKT50.2 (50.6 %) and in T. roseum (56.6 %).
Asunto(s)
Bacterias/química , Chloroflexi/química , Fosfolípidos/química , Ácidos Grasos/química , Manosa/químicaRESUMEN
Structural identities of the major phospholipid (PL-2), minor phospholipid (PL-1) and trace phospholipid (PL-0) from representative strains of the genera Thermus and Meiothermus were established. Phospholipids were quantified using phosphorus-31 nuclear magnetic resonance ((31)P-NMR). The structures of the major phospholipid (PL-2) from Thermus filiformis MOK14.7 and Meiothermus ruber WRG6.9 were identified as 2'-O-(1,2-diacyl-sn-glycero-3-phospho)-3'-O-(α-N-acetylglucosaminyl)-N-glyceroyl alkylamine (GlcNAc-PGAA) and 2'-O-(2-acylalkyldiol-1-O-phospho)-3'-O-(α-N-acetylglucosaminyl)-N-glyceroyl alkylamine (GlcNAc-diolPGAA). Interestingly, M. ruber contained only a diacyl form of GlcNAc-PGAA (87 %), while T. filiformis contained both GlcNAc-PGAA (59 %) and GlcNAc-diolPGAA (18 %). The structures of the minor phospholipid (PL-1) were established as 2'-O-(1,2-diacyl-sn-glycero-3-phospho)-3'-O-(α-glucosaminyl)-N-glyceroyl alkylamine (GlcN-PGAA, 13 %) in T. filiformis and 2'-O-(1,2-diacyl-sn-glycero-3-phospho)-3'-O-(α-galactosaminyl)-N-glyceroyl alkylamine (GalN-PGAA, 19 %) in M. ruber. This is the first reliable discovery of phosphatidylglyceroylalkylamines modified by glucosamine or galactosamine with a free amino group. No signs of diol-based phosphatidylglyceroylalkylamines were found in PL-1 phospholipids. Similar to PL-2, trace phospholipid (PL-0) from T. filiformis contained both unsubstituted diol-based phosphatidylglyceroylalkylamine (diolPGAA) and PGAA, while M. ruber contained only free PGAA. Unlike analysis using TLC, the diol form of phosphatidylglyceroylalkylamines is clearly resolved from the diacyl form via (31)P-NMR.
Asunto(s)
Fosfolípidos/análisis , Fosfolípidos/química , Thermus/química , Cromatografía en Capa Delgada , Espectroscopía de Resonancia Magnética , Estructura Molecular , Fosfolípidos/aislamiento & purificación , Espectrometría de Masa por Ionización de ElectrosprayRESUMEN
Bifidobacteria are dominant members of the microbial community in the intestinal tract of infants, and studies have shown that glycolipids extracted from the cell surface of these bacteria elicit beneficial immune responses. Accordingly, the identification and structural characterization of glycolipids from the cell wall of bifidobacteria is the first step in correlating glycolipid structure with biological activity. Using whole cell MALDI as a screening tool, we herein present for the first time the identification and structural elucidation of the major polar lipids from Bifidobacterium longum subs. infantis. The lipids identified include an unprecedented plasmenyl cyclophosphatidic acid and a mixed acetal glycolipid, with the latter subsequently being isolated and found to suppress the innate immune response.
Asunto(s)
Bifidobacterium/química , Glucolípidos/química , Intestinos/química , Intestinos/inmunología , Intestinos/microbiología , Lípidos/química , Sulfaleno/química , Adhesión Bacteriana/inmunología , Bifidobacterium/inmunología , Bifidobacterium/metabolismo , Glucolípidos/metabolismo , Humanos , Lípidos/inmunología , Espectrometría de Masa por Láser de Matriz Asistida de Ionización DesorciónRESUMEN
A novel bacterium, strain Br(T), was isolated from gamma-irradiated soils of the Britannia drift, Lake Wellman Region, Antarctica. This isolate was rod-shaped, endospore forming, Gram-stain-variable, catalase-positive, oxidase-negative and strictly aerobic. Cells possessed a monotrichous flagellum. Optimal growth was observed at 18 °C, pH 7.0 in PYGV or R2A broth. The major cellular fatty acid was anteiso-C15â:â0 (63.4â%). Primary identified lipids included phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylglycerol. Total phospholipid was 60â% (w/w) of the total lipid extract. MK-7 was the dominant isoprenoid quinone. The genomic DNA G+C content was 55.6 mol%. Based on 16S rRNA gene sequence similarity, strain Br(T) clusters within the genus Paenibacillus with similarity values ranging from 93.9 to 95.1â%. Phylogenetic analyses by maximum-likelihood, maximum-parsimony and neighbour-joining methods revealed that strain Br(T) clusters with Paenibacillus daejeonensis (AF290916), Paenibacillus tarimensis (EF125184) and Paenibacillus pinihumi (GQ423057), albeit with weak bootstrap support. On the basis of phenotypic, chemotaxonomic and phylogenetic characteristics, we propose that strain Br(T) represents a novel species, Paenibacillus darwinianus sp. nov. The type strain is Br(T) (â=âDSM 27245(T)â=âICMP 19912(T)).
Asunto(s)
Paenibacillus/clasificación , Filogenia , Microbiología del Suelo , Regiones Antárticas , Técnicas de Tipificación Bacteriana , Composición de Base , Ácidos Grasos/química , Datos de Secuencia Molecular , Paenibacillus/genética , Paenibacillus/aislamiento & purificación , Fosfolípidos/química , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Vitamina K 2/análogos & derivados , Vitamina K 2/químicaRESUMEN
A strictly aerobic, thermophilic, moderately acidophilic, non-spore-forming bacterium, strain P373(T), was isolated from geothermally heated soil at Waikite, New Zealand. Cells were filamentous rods, 0.2-0.4 µm in diameter and grew in chains up to 80 µm in length. On the basis of 16S rRNA gene sequence similarity, strain P373(T) was shown to belong to the family Chitinophagaceae (class Sphingobacteriia) of the phylum Bacteroidetes, with the most closely related cultivated strain, Chitinophaga pinensis UQM 2034(T), having 87.6â% sequence similarity. Cells stained Gram-negative, and were catalase- and oxidase-positive. The major fatty acids were i-15â:â0 (10.8â%), i-17â:â0 (24.5â%) and i-17â:â0 3-OH (35.2â%). Primary lipids were phosphatidylethanolamine, two unidentified aminolipids and three other unidentified polar lipids. The presence of sulfonolipids (N-acyl-capnines) was observed in the total lipid extract by mass spectrometry. The G+C content of the genomic DNA was 47.3 mol% and the primary respiratory quinone was MK-7. Strain P373(T) grew at 35-63 °C with an optimum temperature of 60 °C, and at pH 5.5-8.7 with an optimum growth pH of 7.3-7.4. NaCl tolerance was up to 5â% (w/v) with an optimum of 0.1-0.25â% (w/v). Cell colonies were non-translucent and pigmented vivid yellow-orange. Cells displayed an oxidative chemoheterotrophic metabolism. The distinct phylogenetic position and the phenotypic characteristics separate strain P373(T) from all other members of the phylum Bacteroidetes and indicate that it represents a novel species in a new genus, for which the name Thermoflavifilum aggregans gen. nov., sp. nov. is proposed. The type strain of the type species is P373(T) (â=âICMP 20041(T)â=âDSM 27268(T)).
Asunto(s)
Bacteroidetes/clasificación , Filogenia , Microbiología del Suelo , Técnicas de Tipificación Bacteriana , Bacteroidetes/genética , Bacteroidetes/aislamiento & purificación , Composición de Base , ADN Bacteriano/genética , Ácidos Grasos/química , Calor , Datos de Secuencia Molecular , Nueva Zelanda , Fosfatidiletanolaminas/química , Pigmentación , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Vitamina K 2/análogos & derivados , Vitamina K 2/químicaRESUMEN
To date, the structures of the glycolipids from Lactobacillus plantarum, a commonly used beneficial probiotic, have not been conclusively assigned. Herein, we report for the first time, the full characterisation of the four principal glycolipids of the L. plantarum cell wall using sugar, linkage and FAME analysis, as well as ESI-MS/MS and 1D- and 2D-NMR spectroscopy, and assign the major glycolipids as being: α-D-Glcp-diglyceride, α-D-Galp-(1â2)-α-D-Glcp-diglyceride, ß-D-Glcp-(1â6)-α-D-Galp-(1â2)-6-O-acyl-α-D-Glcp-diglyceride and ß-D-Glcp-(1â6)-α-D-Galp-(1â2)-α-D-Glcp-diglyceride.
Asunto(s)
Glucolípidos/química , Lactobacillus plantarum/química , Conformación de Carbohidratos , Secuencia de Carbohidratos , Cromatografía en Gel , Ácidos Grasos/química , Galactosa/química , Glucosa/química , Glucolípidos/aislamiento & purificación , Espectroscopía de Resonancia Magnética , Datos de Secuencia Molecular , Estructura Molecular , Espectrometría de Masa por Ionización de Electrospray , EstereoisomerismoRESUMEN
An aerobic, saccharolytic, obligately thermophilic, motile, non-spore-forming bacterium, strain T49(T), was isolated from geothermally heated soil at Hell's Gate, Tikitere, New Zealand. On the basis of 16S rRNA gene sequence similarity, T49(T) is the first representative of a new class in the newly described phylum Armatimonadetes, formerly known as candidate division OP10. Cells of strain T49(T) stained Gram-negative and were catalase-positive and oxidase-negative. Cells possessed a highly corrugated outer membrane. The major fatty acids were 16â:â0, i17â:â0 and ai17â:â0. The G+C content of the genomic DNA was 54.6 mol%. Strain T49(T) grew at 50-73 °C with an optimum temperature of 68 °C, and at pH 4.7-5.8 with an optimum growth pH of 5.3. A growth rate of 0.012 h(-1) was observed under optimal temperature and pH conditions. The primary respiratory quinone was MK-8. Optimal growth was achieved in the absence of NaCl, although growth was observed at NaCl concentrations as high as 2â% (w/v). Strain T49(T) was able to utilize mono- and disaccharides such as cellobiose, lactose, mannose and glucose, as well as branched or amorphous polysaccharides such as starch, CM-cellulose, xylan and glycogen, but not highly linear polysaccharides such as crystalline cellulose or cotton. On the basis of its phylogenetic position and phenotypic characteristics, we propose that strain T49(T) represents a novel bacterial genus and species within the new class Chthonomonadetes classis nov. of the phylum Armatimonadetes. The type strain of Chthonomonas calidirosea gen. nov., sp. nov. is T49(T) (â=âDSM 23976(T)â=âICMP 18418(T)).