RESUMEN

Seven new cyclic depsipeptides, clavariopsins C-I (3-9), together with two known congeners, clavariopsins A and B (1 and 2), were isolated from the aquatic hyphomycete Clavariopsis aquatica. Their planar structures, which consist of nine amino acids and one α-hydroxy acid, were elucidated by NMR spectroscopy and HRESIMS. The absolute configurations were established by the advanced Marfey's method and chiral-phase HPLC analysis. Their antifungal and cytotoxic activities were evaluated against six plant pathogenic fungi (Botrytis cinerea, Magnaporthe oryzae, Colletotrichum orbiculare, Fusarium oxysporum, Alternaria alternata, and Aspergillus niger) and a cancer cell line (HeLa-S3), respectively. The majority of the compounds exhibited potent antifungal activity against the fungi tested (minimum inhibition dose = 0.01-10 µg/disk) and induced hyphal swelling in A. niger (minimum effective dose = 0.3-3 µg/disk), whereas the compounds exhibited no cytotoxicity toward the cancer cell line. The results suggest that the clavariopsins could be a promising class of antifungal agents.

Asunto(s)

Antifúngicos/aislamiento & purificación , Antifúngicos/farmacología , Depsipéptidos/aislamiento & purificación , Depsipéptidos/farmacología , Hongos Mitospóricos/química , Antifúngicos/química , Antineoplásicos/farmacología , Depsipéptidos/química , Células HeLa , Humanos , Estructura Molecular , Espectrometría de Masa por Ionización de Electrospray

RESUMEN

Three new compounds, enhygromic acid (1) and deoxyenhygrolides A (2) and B (3), were isolated from a marine myxobacterium, Enhygromyxa sp. Compound 1 was found to be an acrylic acid derivative with a rare polycyclic carbon skeleton, decahydroacenaphthylene, by spectroscopic analyses. Compounds 2 and 3 were deoxy analogs of the known γ-alkylidenebutenolides, enhygrolides. Compound 1 exhibited cytotoxicity against B16 melanoma cells and anti-bacterial activity against Bacillus subtilis, and enhanced the NGF-induced neurite outgrowth of PC12 cells.

Asunto(s)

Organismos Acuáticos/química , Diterpenos/química , Myxococcales/química , Animales , Antibacterianos/química , Antibacterianos/farmacología , Bacillus subtilis/efectos de los fármacos , Línea Celular Tumoral , Diterpenos/farmacología , Neuritas/química , Células PC12 , Ratas

RESUMEN

Fermentation by Corynebacterium glutamicum is used by various industries to produce L-Glutamate, and the heat-killed cell preparation of this bacterium (HCCG) is a by-product of the fermentation process. In present study, we evaluated the immunostimulating and survival effects against enterohemorrhagic Escherichia coli (STEC) infection of HCCG. HCCG significantly stimulated in vitro IgA and interleukin-12 p70 production in murine Peyer's patch cells and peritoneal macrophages, respectively. Oral administration of 10 mg/kg body weight (BW) of HCCG for seven consecutive days stimulated IgA concentration in murine cecal digesta. Mice were orally administered HCCG for 17 consecutive days (d0-d17), and challenged with STEC on d4 to d6. Survival of mice tended to improve by 100 mg/kg BW of HCCG administration compared with those in control group. In conclusion, HCCG supplementation was found to prevent STEC infection in mice, and thus it may have the potential to stimulate the immune status of mammals.

Asunto(s)

Corynebacterium glutamicum/citología , Diarrea/inmunología , Diarrea/microbiología , Escherichia coli Enterohemorrágica/fisiología , Calor , Animales , Diarrea/metabolismo , Diarrea/prevención & control , Inmunoglobulina A/biosíntesis , Interleucina-12/biosíntesis , Ratones , Análisis de Supervivencia

RESUMEN

Despite their fastidious nature, marine myxobacteria have considerable genetic potential to produce novel secondary metabolites. The marine myxobacterium Haliangium ochraceum SMP-2 produces the antifungal polyketide haliangicin (1), but its productivity is unsatisfactory. The biosynthetic gene cluster hli (47.8 kbp) associated with 1 was identified and heterologously expressed in Myxococcus xanthus to permit the production of 1 with high efficiency (tenfold greater amount and threefold faster in growth speed compared with the original producer), as well as the generation of bioactive unnatural analogues of 1 through gene manipulation. A unique acyl-CoA dehydrogenase was found to catalyse an unusual γ,δ-dehydrogenation of the diketide starter unit, leading to the formation of the terminal alkene moiety of 1. Biological evaluation of the analogues obtained through this study revealed that their bioactivities (anti-oomycete and cytotoxic activities) can be modified by manipulating the vinyl epoxide at the terminus opposite the ß-methoxyacrylate pharmacophore.

Asunto(s)

Antifúngicos , Ácidos Grasos Insaturados/genética , Myxococcales/metabolismo , Transgenes , Ácidos Grasos Insaturados/biosíntesis

RESUMEN

Myxobacteria of marine origin are rare and hard-to-culture microorganisms, but they genetically harbor high potential to produce novel antibiotics. An extensive investigation on the secondary metabolome of the unique marine myxobacterium Haliangium ochraceum SMP-2 led to the isolation of a new polyketide-nonribosomal peptide hybrid product, haliamide (1). Its structure was elucidated by spectroscopic analyses including NMR and HR-MS. Haliamide (1) showed cytotoxicity against HeLa-S3 cells with IC50 of 12 µM. Feeding experiments were performed to identify the biosynthetic building blocks of 1, revealing one benzoate, one alanine, two propionates, one acetate and one acetate-derived terminal methylene. The biosynthetic gene cluster of haliamide (hla, 21.7 kbp) was characterized through the genome mining of the producer, allowing us to establish a model for the haliamide biosynthesis. The sulfotransferase (ST)-thioesterase (TE) domains encoded in hlaB appears to be responsible for the terminal alkene formation via decarboxylation.

Asunto(s)

Antineoplásicos/metabolismo , Deltaproteobacteria/metabolismo , Metaboloma , Péptidos/metabolismo , Policétidos/metabolismo , Antineoplásicos/aislamiento & purificación , Antineoplásicos/farmacología , Organismos Acuáticos , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Supervivencia Celular/efectos de los fármacos , Deltaproteobacteria/química , Deltaproteobacteria/genética , Expresión Génica , Células HeLa , Humanos , Concentración 50 Inhibidora , Familia de Multigenes , Péptidos/aislamiento & purificación , Péptidos/farmacología , Policétidos/aislamiento & purificación , Policétidos/farmacología , Estructura Terciaria de Proteína , Sulfotransferasas/química , Sulfotransferasas/genética , Sulfotransferasas/metabolismo , Tioléster Hidrolasas/química , Tioléster Hidrolasas/genética , Tioléster Hidrolasas/metabolismo

RESUMEN

Four maleic anhydride derivatives, tricladolides A-D (1-4), and three alkylidene succinic acid derivatives, tricladic acids A-C (5-7), were isolated from the aquatic hyphomycete Tricladium castaneicola. The structures of these compounds were determined by spectroscopic analysis, and all were found to be novel. The compounds exhibited inhibitory activity against fungi, particularly Phytophthora sp., a plant pathogen of oomycetes. The inhibitory activity of these metabolites revealed the importance of the cyclic anhydride structure and the lipophilicity of the alkyl side chain. On the other hand, the cytotoxicity of the compounds against B16 melanoma cells indicated that the cyclic anhydride structure was not essential.

Asunto(s)

Anhídridos Maleicos/aislamiento & purificación , Anhídridos Maleicos/farmacología , Hongos Mitospóricos/química , Phytophthora/efectos de los fármacos , Succinatos/aislamiento & purificación , Succinatos/farmacología , Ensayos de Selección de Medicamentos Antitumorales , Japón , Anhídridos Maleicos/química , Melanoma Experimental/tratamiento farmacológico , Estructura Molecular , Resonancia Magnética Nuclear Biomolecular , Relación Estructura-Actividad , Succinatos/química

RESUMEN

Succinate is a core biochemical building block; optimizing succinate production from biomass by microbial fermentation is a focus of basic and applied biotechnology research. Lowering pH in anaerobic succinate fermentation culture is a cost-effective and environmentally friendly approach to reducing the use of sub-raw materials such as alkali, which are needed for neutralization. To evaluate the potential of bacteria-based succinate fermentation under weak acidic (pH <6.2) and anaerobic conditions, we characterized the anaerobic metabolism of Enterobacter aerogenes AJ110637, which rapidly assimilates glucose at pH 5.0. Based on the profile of anaerobic products, we constructed single-gene knockout mutants to eliminate the main anaerobic metabolic pathways involved in NADH re-oxidation. These single-gene knockout studies showed that the ethanol synthesis pathway serves as the dominant NADH re-oxidation pathway in this organism. To generate a metabolically engineered strain for succinate production, we eliminated ethanol formation and introduced a heterogeneous carboxylation enzyme, yielding E. aerogenes strain ΔadhE/PCK. The strain produced succinate from glucose with a 60.5% yield (grams of succinate produced per gram of glucose consumed) at pH <6.2 and anaerobic conditions. Thus, we showed the potential of bacteria-based succinate fermentation under weak acidic conditions.

Asunto(s)

Enterobacter aerogenes/metabolismo , Ácido Succínico/metabolismo , Anaerobiosis , Fermentación/fisiología , Succinatos/metabolismo

RESUMEN

Skin surface bacteria contribute to body odor, especially axillary odor. We aimed to investigate anaerobic bacteria that had not been previously studied for axillary odor formation. A new anaerobic Anaerococcus sp. A20, that releases 3-hydroxy-3-metyl-hexanoic acid (HMHA, main component of axillary odor) from its glutamyl conjugate, was discovered from axillary isolates. This strain showed strong resistance to the antimicrobial agents, triclosan and 4-isopropyl-3-methylphenol; therefore, we screened plant extracts that inhibit the A20 strain. We discovered that pentagalloyl glucose (PGG) extracted from the Chinese Gall plant exhibited both antibacterial and inhibitory activities against HMHA release by the A20 strain. As the excellent antibacterial activity and inhibitory effect of PGG against HMHA release were seen in vitro, we conducted an open study to evaluate the deodorant effects of PGG on axillary odor. The sensory tests on odor strength showed that application of the PGG solution could reduce axillary odors in vivo. Although there was a small change in axillary microbiota, the microbial count of A20 significantly reduced. These results strongly indicate PGG as a new innovative deodorant material that only affects odor-releasing bacteria in the axillary microbiota.

Asunto(s)

Antibacterianos/farmacología , Axila/microbiología , Bacterias Grampositivas/efectos de los fármacos , Taninos Hidrolizables/farmacología , Piel/microbiología , Caproatos/metabolismo , Cresoles/farmacología , Farmacorresistencia Bacteriana , Femenino , Genes Bacterianos , Bacterias Grampositivas/genética , Bacterias Grampositivas/aislamiento & purificación , Bacterias Grampositivas/metabolismo , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Tipificación Molecular , Odorantes , Filogenia , ARN Ribosómico 16S/genética , Sudor/microbiología , Triclosán/farmacología

RESUMEN

A myxobacterial strain, designated SYR-2(T), was obtained from a mud sample from an estuarine marsh alongside the Yoshino River, Shikoku, Japan. It had rod-shaped vegetative cells and formed bacteriolytic enlarging colonies or so-called 'swarms' in the agar media. Fruiting-body-like globular to polyhedral cell aggregates and myxospore-like spherical to ellipsoidal cells within them were observed. Those features coincided with the general characteristics of myxobacteria. The strain was mesophilic and strictly aerobic. Growth of SYR-2(T) was observed at 18-40 °C (optimum, 30-35 °C), pH 5.5-8.3 (optimum, pH 7.0-7.5) and with 0.0-2.5 % (w/v) NaCl (optimum, 0.2-1.0 %). Both Mg(2+) and Ca(2+) were essential cations for the growth. The predominant fatty acids were iso-C15 : 0 (43.8 %), iso-C17 : 0 (22.4 %) and iso-C16 : 0 (9.6 %). A C20 : 4 fatty acid [arachidonic acid (4.3 %)], iso-C19 : 0 (1.5 %) and anteiso-acids [ai-C15 : 0 (0.5 %), ai-C17 : 0 (0.3 %)] were also detected. The G+C content of the DNA was 69.7 mol%. The strain contained menaquinone-7 (MK-7) as the major respiratory quinone. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain SYR-2(T) belonged to the suborder Nannocystineae, order Myxococcales in the class Deltaproteobacteria, and the strain was most closely related to two type strains of marine myxobacteria, Enhygromyxa salina SHK-1(T) and Plesiocystis pacifica SIR-1(T), with 96.5 % and 96.0 % similarities, respectively. These characteristics determined in this polyphasic study suggested that strain SYR-2(T) represents a novel species in a new genus of myxobacteria. The name Pseudenhygromyxa salsuginis gen. nov., sp. nov. is proposed to accommodate this isolate, and the type strain of Pseudenhygromyxa salsuginis is SYR-2(T) ( = NBRC 104351(T) = DSM 21377(T)).

Asunto(s)

Estuarios , Myxococcales/clasificación , Filogenia , Microbiología del Agua , Humedales , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/genética , Ácidos Grasos/análisis , Sedimentos Geológicos/microbiología , Japón , Datos de Secuencia Molecular , Myxococcales/genética , Myxococcales/aislamiento & purificación , ARN Ribosómico 16S/genética , Agua de Mar/microbiología , Análisis de Secuencia de ADN , Vitamina K 2/análogos & derivados , Vitamina K 2/análisis

RESUMEN

The Japanese mealybug, Planococcus kraunhiae, is suitable as a model insect for biosynthetic studies on mealybug pigments. Four yellow pigments, including two novel ones, were isolated from the mealybug bodies and characterized as endocrocin, a dicarboxylic acid named fujikonaic acid (1), emodin 1-O-ß-D-glucopyranoside and 7-hydroxyemodin 1-O-ß-D-glucopyranoside (2). The enzymatic activity of emodin 1-O-glucosyltransferase was observed in the extracts of insect bodies.

Asunto(s)

Insecto Planococcus/química , Animales , Antracenos/química , Antracenos/aislamiento & purificación , Emodina/metabolismo , Glucosiltransferasas/metabolismo , Pigmentos Biológicos/química , Pigmentos Biológicos/aislamiento & purificación

RESUMEN

A two-component system (TCS) comprising a histidine kinase (HK) sensor and a response regulator (RR) plays important roles in regulating the virulence of many pathogenic bacteria. We used a new screening method to isolate novel inhibitor Art1 against bacterial sensory HK from an acetone extract of solid cultures of Articulospora sp., an aquatic hypomycete. Art1 inhibited the ATP-dependent autophosphorylation of recombinant glutathione S-transferase-fusion protein SasA, a cyanobacterial HK, with an IC50 value of 9.5 microg/ml.

Asunto(s)

Ascomicetos/metabolismo , Cianobacterias/enzimología , Naftoles/química , Naftoles/farmacología , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Quinasas/metabolismo , Ascomicetos/química , Histidina Quinasa , Espectroscopía de Resonancia Magnética , Estructura Molecular , Naftoles/aislamiento & purificación , Naftoles/metabolismo , Inhibidores de Proteínas Quinasas/aislamiento & purificación , Inhibidores de Proteínas Quinasas/metabolismo

RESUMEN

The diversity of type I modular polyketide synthase (PKS) was explored by PCR amplification of DNA encoding ketosynthase and acyltransferase domains in myxobacteria. The sequencing of the amplicons revealed that many PKS genes were distantly related to the published sequences. Thus, myxobacteria may be excellent resources for novel and diverse polyketides.

Asunto(s)

Genes Bacterianos , Myxococcales/genética , Sintasas Poliquetidas/genética , ADN Bacteriano/genética , Variación Genética , Datos de Secuencia Molecular , Myxococcales/enzimología , Filogenia , Reacción en Cadena de la Polimerasa , Análisis de Secuencia de ADN

RESUMEN

Marine myxobacteria are rare culture-resistant microorganisms, several strains of which have been identified by research groups in Asia. Paraliomyxa miuraensis, a slightly halophilic myxobacterium discovered in Japan, produces the cyclic hybrid polyketide-peptide antibiotics known as miuraenamides A and B, whose taxonomical and biological characteristics have been reported previously. Herein, we describe the chemical characterization of these two miuraenamides and introduce four new members of the miuraenamide family. We carried out the complete structural analysis of miuraenamides A and B on the basis of NMR spectroscopic analysis and elucidated the absolute configuration of miuraenamide A by chemical derivatization and subsequent use of the modified Mosher method or the Marfey method. Miuraenamides C-F were isolated from the same strain of the bacterium as miuraenamides A and B. The structure-antimicrobial-activity relationships of the six natural metabolites and four chemically derived compounds demonstrated the importance of both the macrocyclic structure and the beta-methoxyacrylate moiety.

Asunto(s)

Antiinfecciosos/aislamiento & purificación , Depsipéptidos/aislamiento & purificación , Myxococcales/química , Péptidos Cíclicos/aislamiento & purificación , Antiinfecciosos/química , Cromatografía Líquida de Alta Presión , Depsipéptidos/química , Resonancia Magnética Nuclear Biomolecular , Péptidos Cíclicos/química

RESUMEN

A fungus producing magenta was isolated from cellulosic material by visual observation on Czapek's agar media and the product was conventionally analyzed. The fungal strain that produced magenta pigment was closely related to Phoma herbarum. The type of fibers added to Czapek's medium influenced which pigments were produced. Mycelia attached to the surface of nylon-6 and excreted magenta pigment into the fibers. The pigment structure was partially determined. This is the first report of the production of magenta pigment by a microorganism specifically in the presence of nylon-6 fibers, via an unknown mechanism. This phenomenon raises the question of why and how the fungus disperses the pigment inside the fiber and suggests that fabrics can be dyed using microorganisms.

Asunto(s)

Ascomicetos/metabolismo , Pigmentos Biológicos/biosíntesis , Colorantes de Rosanilina/metabolismo , Ascomicetos/genética , Colorantes/metabolismo , Filogenia

RESUMEN

A slightly halophilic myxobacterial strain, SMH-27-4, was isolated from nearshore soil and shown to belong to a new myxobacterium genus based on phylogenetic analysis. This slowly-growing myxobacterium produced the novel antibiotic depsipeptides miuraenamides A and B. Their physico-chemical properties and molecular formulas, C34H42N3O7Br and C34H42N3O7I, were determined. Miuraenamides A exhibited potent and selective inhibition against a phytopathogenic microorganism, Phytophthora sp., and moderate inhibition against some fungi and yeasts, but was ineffective against bacteria. Both of the metabolites inhibited NADH oxidase at IC50 values of 50 microM, suggesting, like beta-methoxyacrylate-type antibiotics, the electron transfer system of the mitochondrial respiratory chain as the cellular target.

Asunto(s)

Antibacterianos/metabolismo , Antifúngicos/metabolismo , Depsipéptidos/aislamiento & purificación , Depsipéptidos/farmacología , Myxococcales/clasificación , Myxococcales/metabolismo , Antibacterianos/aislamiento & purificación , Antibacterianos/farmacología , Antifúngicos/aislamiento & purificación , Antifúngicos/farmacología , Bacterias/efectos de los fármacos , Depsipéptidos/química , Hongos/efectos de los fármacos , Estructura Molecular , Myxococcales/genética , Filogenia

RESUMEN

Novel bacteria were discovered using an isolation technique consisting of (i) selection of microorganisms that grew on soil-extract agar medium, but not on conventional media, and (ii) detection of small microbial colonies with a microscope. Three bacterial strains thus isolated were provisionally designated Shinshu-th1, -th2, -th 3, and five actinomycete strains, Shinshu-MS-01, -02, -03, -04, -05, respectively. Sequence analysis of their 16S rDNA showed that th1 had 95--96% homology with three unculturable bacteria, and th2 had 96% similarity to Bradyrhizobium sp., one unculturable and one unidentified bacterial strain. A phylogenetic study indicated that both strains were alpha-Proteobacteria belonging to the order Rhizobiales and the family Bradyrhizobiaceae. Since they had low homology (96%) with their close relatives, it is possible that th1 and th2 belong to a new genus. The actinomycetes Shinshu-MS-02 and -03 had 95--96% homology with four strains of Actinomadura, -04 had 95--96% similarity to Streptosporangium and Microbispora, and -05 had 97--98% homology with three strains of Acrocarpospora, Herbidospora and Planotetraspora. According to the phylogenetic study, both 02 and 03 are possibly new species of Actinomadura, -04 of Streptosporangium, and -05 of Acrocarpospora. Shinshu-th 3 and -MS-01 were identified as Mycobacterium cookii and Frankia sp., respectively, having 99% homology with these species.

Asunto(s)

Actinobacteria/aislamiento & purificación , Actinobacteria/metabolismo , Agar/metabolismo , Bradyrhizobiaceae/aislamiento & purificación , Bradyrhizobiaceae/metabolismo , Técnicas de Cultivo de Célula/métodos , Microbiología del Suelo , Actinobacteria/citología , Actinobacteria/genética , Bradyrhizobiaceae/citología , Bradyrhizobiaceae/genética , Proliferación Celular , ARN Ribosómico 16S/genética , Especificidad de la Especie

RESUMEN

Marcha or murcha is a traditional amylolytic starter used to produce sweet-sour alcoholic drinks, commonly called jaanr in the Himalayan regions of India, Nepal, Bhutan, and Tibet (China). The aim of this study was to examine the microflora of marcha collected from Sikkim in India, focusing on yeast flora and their roles. Twenty yeast strains were isolated from six samples of marcha and identified by genetic and phenotypic methods. They were first classified into four groups (Group I, II, III, and IV) based on physiological features using an API test. Phylogenetic, morphological, and physiological characterization identified the isolates as Saccharomyces bayanus (Group I); Candida glabrata (Group II); Pichia anomala (Group III); and Saccharomycopsis fibuligera, Saccharomycopsis capsularis, and Pichia burtonii (Group IV). Among them, the Group I, II, and III strains produced ethanol. The isolates of Group IV had high amylolytic activity. Because all marcha samples tested contained both starch degraders and ethanol producers, it was hypothesized that all four groups of yeast (Group I, II, III, and IV) contribute to starch-based alcohol fermentation.

Asunto(s)

Bebidas Alcohólicas/microbiología , Amilasas/metabolismo , Microbiología de Alimentos , Levaduras/clasificación , Levaduras/aislamiento & purificación , Fermentación , Humanos , India , Filogenia

RESUMEN

Three mesophilic bacteria (strains AMX 26B(T), UR374_02 and 12-3(T)) isolated respectively from an anaerobic digester, human urine and urban riverside soil were characterized. Cells were Gram-negative, motile, non-sporulating, straight to curved rods with one polar flagellum and had a strictly respiratory metabolism with O(2) as the preferential terminal electron acceptor. Phylogenetic analysis based on 16S rRNA gene sequences revealed that all strains clustered within the Xanthomonadaceae branch of the Proteobacteria. Isolates AMX 26B(T) and UR374_02 exhibited 100 % 16S rRNA gene sequence similarity and both were related to strain 12-3(T) (99.6 % similarity). The closest relative of all the isolates was Pseudoxanthomonas broegbernensis DSM 12573(T) (similarity 97.1-97.5 %), and they were equidistantly related to Xanthomonas species (95.4-96.6 %), Stenotrophomonas species (95.3-96.1 %) and Pseudoxanthomonas taiwanensis ATCC BAA-4040(T) (95.3-95.4 %). Chemotaxonomic and biochemical data (branched-chain cellular fatty acid pattern without C(13 : 0) iso 3-OH, ubiquinone with eight isoprenoid units, limited range of substrates used, ability to reduce nitrite but not nitrate with the production of N(2)O) supported their affiliation to the genus Pseudoxanthomonas. The results of DNA-DNA hybridization and/or phenotypic analysis allowed them to be differentiated from the two Pseudoxanthomonas species with validly published names and showed that strain 12-3(T) was genomically and phenotypically distinct from the other two isolates. On the basis of these results, two novel species of the genus Pseudoxanthomonas are proposed: Pseudoxanthomonas mexicana sp. nov., consisting of strains AMX 26B(T) (=ATCC 700993(T)=CIP 106674(T)=JCM 11524(T)) (type strain) and UR374_02 (=DSM 15133), and Pseudoxanthomonas japonensis sp. nov., consisting of strain 12-3(T) (=CCUG 48231(T)=CIP 107388(T)=JCM 11525(T)). The report of these two novel species leads to the emendation of the description of the genus Pseudoxanthomonas and the re-evaluation of the phenotype of P. broegbernensis DSM 12573(T) necessitates the emendation of its description.

Asunto(s)

Reactores Biológicos/microbiología , Microbiología del Suelo , Orina/microbiología , Xanthomonadaceae/clasificación , Xanthomonadaceae/aislamiento & purificación , Aerobiosis , Antibacterianos/farmacología , Técnicas de Tipificación Bacteriana , Composición de Base , Metabolismo de los Hidratos de Carbono , ADN Bacteriano/química , ADN Bacteriano/aislamiento & purificación , ADN Ribosómico/química , ADN Ribosómico/aislamiento & purificación , Ácidos Grasos/análisis , Ácidos Grasos/aislamiento & purificación , Flagelos , Genes de ARNr , Violeta de Genciana , Humanos , Datos de Secuencia Molecular , Movimiento , Nitritos/metabolismo , Hibridación de Ácido Nucleico , Oxígeno/metabolismo , Fenazinas , Filogenia , ARN Bacteriano/genética , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Esporas Bacterianas/citología , Stenotrophomonas/genética , Ubiquinona/análisis , Ubiquinona/aislamiento & purificación , Xanthomonadaceae/citología , Xanthomonadaceae/fisiología , Xanthomonas/genética

RESUMEN

Three Gram-negative, aerobic, rod-shaped bacterial strains were isolated, from the pollen of Japanese flowers, as producers of xylitol; these strains were subjected to a polyphasic taxonomic study. Phylogenetic analyses of the 16S rRNA gene sequences demonstrated that these three isolates formed a new cluster within a group of acetic acid bacteria in the alpha-Proteobacteria. The characteristics of the three isolates were as follows: (i) their predominant quinone was Q-10; (ii) their cellular fatty acid profile contained major amounts of 2-hydroxy acids and an unsaturated straight-chain acid (C(18 : 1)omega7c); and (iii) their DNA G+C contents were in the range 51.9-52.3 mol%, which is around the lower limit of the reported range for the genera of acetic acid bacteria. The negligible or very weak productivity of acetic acid from ethanol and the osmophilic growth properties distinguished these strains from other acetic acid bacteria. The unique phylogenetic and phenotypic characteristics suggest that the three isolates should be classified within a novel genus and species with the proposed name Saccharibacter floricola gen. nov., sp. nov. The type strain is strain S-877(T) (=AJ 13480(T)=JCM 12116(T)=DSM 15669(T)).

Asunto(s)

Acetobacteraceae/clasificación , Acetobacteraceae/aislamiento & purificación , Polen/microbiología , Ácido Acético/metabolismo , Acetobacteraceae/citología , Acetobacteraceae/fisiología , Aerobiosis , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/química , ADN Bacteriano/aislamiento & purificación , ADN Ribosómico/química , ADN Ribosómico/aislamiento & purificación , Etanol/metabolismo , Ácidos Grasos/análisis , Ácidos Grasos/aislamiento & purificación , Genes de ARNr , Violeta de Genciana , Japón , Datos de Secuencia Molecular , Concentración Osmolar , Fenazinas , Filogenia , Quinonas/análisis , Quinonas/aislamiento & purificación , ARN Bacteriano/genética , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Xilitol/metabolismo

RESUMEN

Dynamic change in microbial flora was monitored with an oxygen electrode. The 1st phase microorganisms, which first grew well in LB medium, were followed by the 2nd phase microorganisms, which supposedly assimilated microbial cells of the 1st phase and their metabolites. In a similar way, a change in microbial flora was observed from the 1st phase to the 4th phase in 84 hr. Based on this observation, prolonged enrichment culture was done for as long as two months to increase the ratio of existence of rare microorganisms. From these culture liquids, four slow-growing bacteria (provisionally named Shinshu-ah1, -ah2, -ah3, and -ah4), which formed scarcely visible small colonies, were isolated. Sequence analysis of their 16S rDNA showed that Shinshu-ah1 had 97% homology with Bradyrhizobium japonicum and uncultured alpha proteobacterium clone blaii 16, Shinshu-ah2 91% with Rasbo bacterium, Alpha proteobacterium 34619, Bradyrhizobium genosp. P, Afipia felis and an unidentified bacterium, Shinshu-ah3 99% with Methylobacterium mesophilicum, and Shinshu-ah4 95% with Agromyces ramosus DSM 43045. Phylogenetic study indicated that Shinshu-ah2 had a possibility to form a new family, Shinshu-ah1 a new genus, and Shinshu-ah4 a new species.

Asunto(s)

Técnicas Bacteriológicas/métodos , Proteobacteria/genética , Proteobacteria/aislamiento & purificación , Afipia/genética , Bradyrhizobium/genética , Bradyrhizobium/crecimiento & desarrollo , Bradyrhizobium/aislamiento & purificación , División Celular , Medios de Cultivo , ADN Ribosómico/genética , Electroquímica/métodos , Electrodos , Methylobacterium/genética , Methylobacterium/crecimiento & desarrollo , Methylobacterium/aislamiento & purificación , Datos de Secuencia Molecular , Oxígeno , Filogenia , Proteobacteria/crecimiento & desarrollo , ARN Ribosómico 16S , Homología de Secuencia de Ácido Nucleico