Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 155
Filtrar
Más filtros

Bases de datos
Tipo del documento
Intervalo de año de publicación
1.
PLoS Pathog ; 17(2): e1009263, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33524062

RESUMEN

Bacteria utilize endoribonuclease-mediated RNA processing and decay to rapidly adapt to environmental changes. Here, we report that the modulation of hns mRNA stability by the endoribonuclease RNase G plays a key role in Salmonella Typhimurium pathogenicity. We found that RNase G determines the half-life of hns mRNA by cleaving its 5' untranslated region and that altering its cleavage sites by genome editing stabilizes hns mRNA, thus decreasing S. Typhimurium virulence in mice. Under anaerobic conditions, the FNR-mediated transcriptional repression of rnc encoding RNase III, which degrades rng mRNA, and simultaneous induction of rng transcription resulted in rapid hns mRNA degradation, leading to the derepression of genes involved in the Salmonella pathogenicity island 1 (SPI-1) type III secretion system (T3SS). Together, our findings show that RNase III and RNase G levels-mediated control of hns mRNA abundance acts as a regulatory pathway upstream of a complex feed-forward loop for SPI-1 expression.


Asunto(s)
Regulación Bacteriana de la Expresión Génica , Islas Genómicas , Estabilidad del ARN , ARN Bacteriano/metabolismo , Salmonella typhimurium/patogenicidad , Animales , Proteínas Bacterianas/genética , Sitios de Unión , Proteínas de Unión al ADN/genética , Femenino , Ratones , Ratones Endogámicos BALB C , Oxígeno/metabolismo , Salmonella typhimurium/genética , Transcriptoma , Sistemas de Secreción Tipo III/genética , Sistemas de Secreción Tipo III/metabolismo , Virulencia/genética
2.
Environ Sci Technol ; 57(49): 20636-20646, 2023 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-38011382

RESUMEN

Cyanobacterial harmful algal blooms (CyanoHABs) pose serious risks to inland water resources. Despite advancements in our understanding of associated environmental factors and modeling efforts, predicting CyanoHABs remains challenging. Leveraging an integrated water quality data collection effort in Iowa lakes, this study aimed to identify factors associated with hazardous microcystin levels and develop one-week-ahead predictive classification models. Using water samples from 38 Iowa lakes collected between 2018 and 2021, feature selection was conducted considering both linear and nonlinear properties. Subsequently, we developed three model types (Neural Network, XGBoost, and Logistic Regression) with different sampling strategies using the nine selected variables (mcyA_M, TKN, % hay/pasture, pH, mcyA_M:16S, % developed, DOC, dewpoint temperature, and ortho-P). Evaluation metrics demonstrated the strong performance of the Neural Network with oversampling (ROC-AUC 0.940, accuracy 0.861, sensitivity 0.857, specificity 0.857, LR+ 5.993, and 1/LR- 5.993), as well as the XGBoost with downsampling (ROC-AUC 0.944, accuracy 0.831, sensitivity 0.928, specificity 0.833, LR+ 5.557, and 1/LR- 11.569). This study exhibited the intricacies of modeling with limited data and class imbalances, underscoring the importance of continuous monitoring and data collection to improve predictive accuracy. Also, the methodologies employed can serve as meaningful references for researchers tackling similar challenges in diverse environments.


Asunto(s)
Cianobacterias , Floraciones de Algas Nocivas , Lagos/microbiología , Iowa
3.
Microb Pathog ; 165: 105460, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35231570

RESUMEN

RNase E-mediated RNA processing and degradation are involved in bacterial adaptation to environmental changes. The RraA regulatory protein, which is highly conserved in γ-proteobacteria, differentially modulates RNase E activity. Recent studies have revealed the association of Salmonella enterica serovar Typhimurium RNase E (STRNase E) with bacterial pathogenicity; however, the molecular mechanisms are unknown. Here, we show that the expression levels of STRraA, a protein regulator of STRNase E activity, affect S. Typhimurium pathogenicity. RNA-sequencing and RT-PCR analyses indicated positive effects of STRraA levels on the abundance of mRNA species from class II flagellar operons. Primer extension analysis further identified STRraA-regulated STRNase E cleavage in the 5' untranslated region of fliDST mRNA. The cleavage affected the stability of this polycistronic mRNA, suggesting that STRraA protects fliDST mRNA from STRNase E cleavage, leading to enhanced flagellar assembly. Accordingly, STRraA positively regulated flagellar assembly and motility. In addition, STrraA-deleted cells showed decreased invasion ability and cytotoxicity in infection of human cervical epithelial carcinoma cells and reduced mortality in a mouse infection model compared to wild-type cells. These results support an active role of STRraA in RNase E-mediated modulation of pathogenesis in S. Typhimurium.


Asunto(s)
Regulación Bacteriana de la Expresión Génica , Salmonella typhimurium , Animales , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Endorribonucleasas , Ratones , ARN Mensajero/genética , ARN Mensajero/metabolismo , Virulencia/genética
4.
Cell Tissue Bank ; 23(3): 591-606, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35277795

RESUMEN

Management of peripheral nerve defects is a complicated problem in clinical contexts. Autologous nerve grafting, a gold standard for surgical treatment, has been well known to have several limitations, such as donor site morbidity, a limited amount of available donor tissue, and size mismatches. Acellular nerve allografts (ANAs) have been developed as an alternative and have been applied clinically with favorable outcomes. However, because of the limited availability of commercialized ANAs due to supplier-related issues and high costs, efforts continue to produce alternative sources for ANAs. The present study evaluated the anatomical and histological characteristics of human peripheral nerves using 25 donated human cadavers. The length, diameter, and branching points of various peripheral nerves (median, ulnar, tibial, lateral femoral cutaneous, saphenous, and sural nerves) in both the upper and lower extremities were evaluated. The cross-sectional area (CSA), ratio of fascicular area, and numbers of fascicles were also evaluated via histologic analysis. CSA, the ratio of fascicular area, and the number of fascicles were analyzed statistically in correlation with demographic data (age, sex, height, weight, BMI). The mean length of all evaluated nerves ranged from 17.1 to 41.4 cm, and the mean diameter of all evaluated nerves ranged from 1.2 to 4.9 mm. Multiple regression analysis revealed correlations between the ratio of fascicular area and sex (p = 0.005) and BMI (p = 0.024) (R2 = 0.051). The results of the present study will be helpful in selecting necessary nerve allograft sources while considering the characteristics of each nerve in the upper and lower extremities during ANAs production.


Asunto(s)
Trasplante de Células Madre Hematopoyéticas , Tejido Nervioso , Cadáver , Humanos , Nervios Periféricos/anatomía & histología , Nervios Periféricos/trasplante , Nervio Sural
5.
Int J Mol Sci ; 23(23)2022 Nov 23.
Artículo en Inglés | MEDLINE | ID: mdl-36498956

RESUMEN

In this paper, chiral intermediate phases composed of two achiral molecules are fabricated by utilizing nanophase separation and molecular hierarchical self-organization. An achiral bent-core guest molecule, exhibiting a calamitic nematic and a dark conglomerate phase according to the temperature, is mixed with another achiral bent-core host molecule possessing a helical nanofilament to separate the phases between them. Two nanosegregated phases are identified, and considerable chiroptical changes, such as circular dichroism and circularly polarized luminescence, are detected at the transition temperatures between the different nanophase-separated states. The nanosegregated chiral phase-wherein the helical nanofilament and dark conglomerate phases are phase-separated-exhibits the highest chiroptical intensities. The luminescence dissymmetry factor, |glum|, in this phase is amplified by an order of magnitude compared with that of another nanosegregated phase, wherein the helical nanofilament and nematic phases are phase-separated.


Asunto(s)
Luminiscencia , Dicroismo Circular , Temperatura , Temperatura de Transición
6.
J Neurogenet ; 35(1): 33-44, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33326321

RESUMEN

The gastrointestinal tract in the adult Drosophila serves as a model system for exploring the mechanisms underlying digestion, absorption and excretion, stem cell plasticity, and inter-organ communication, particularly through the gut-brain axis. It is also useful for studying the cellular and adaptive responses to dietary changes, alterations in microbiota and immunity, and systematic and endocrine signals. Despite the various cell types and distinct regions in the gastrointestinal tract, few tools are available to target and manipulate the activity of each cell type and region, and their gene expression. Here, we report 353 GAL4 lines and several split-GAL4 lines that are expressed in enteric neurons (ENs), progenitors (ISCs and EBs), enterocytes (ECs), enteroendocrine cells (EEs), or/and other cell types that are yet to be identified in distinct regions of the gut. We had initially collected approximately 600 GAL4 lines that may be expressed in the gut based on RNA sequencing data, and then crossed them to UAS-GFP to perform immunohistochemistry to identify those that are expressed selectively in the gut. The cell types and regional expression patterns that are associated with the entire set of GAL4 drivers and split-GAL4 combinations are annotated online at http://kdrc.kr/index.php (K-Gut Project). This GAL4 resource can be used to target specific populations of distinct cell types in the fly gut, and therefore, should permit a more precise investigation of gut cells that regulate important biological processes.


Asunto(s)
Proteínas de Drosophila/genética , Sistema Nervioso Entérico/metabolismo , Tracto Gastrointestinal/metabolismo , Regulación del Desarrollo de la Expresión Génica , Neuronas/metabolismo , Factores de Transcripción/genética , Animales , Eje Cerebro-Intestino/fisiología , Proteínas de Drosophila/metabolismo , Drosophila melanogaster , Factores de Transcripción/metabolismo
7.
Molecules ; 26(19)2021 Oct 06.
Artículo en Inglés | MEDLINE | ID: mdl-34641599

RESUMEN

In this paper, a simple and powerful method to control the induced handedness of helical nanofilaments (HNFs) is presented. The nanofilaments are formed by achiral bent-core liquid crystal molecules employing a cholesteric liquid crystal field obtained by doping a rod-like nematogen with a chiral dopant. Homochiral helical nanofilaments are formed in the nanophase-separated helical nanofilament/cholesteric phase from a mixture with a cholesteric phase. This cholesteric phase forms at a temperature higher than the temperature at which the helical nanofilament in a bent-core molecule appears. Under such conditions, the cholesteric liquid crystal field acts as a driving force in the nucleation of HNFs, realizing a perfectly homochiral domain consisting of identical helical nanofilament handedness.

8.
Int J Syst Evol Microbiol ; 70(7): 4224-4232, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32553048

RESUMEN

A Gram-stain-negative, long-rod-shaped and facultative aerobic bacterium, designated HB-1T, was isolated from a round hay bale at the Kansas State University Beef Stocker Unit. The results of phylogenetic analysis of 16S rRNA gene sequences indicated that strain HB-1T clustered within the genus Gemmobacter and its closest relatives were Gemmobacter aquaticus A1-9T (98.0 %), Gemmobacter lutimaris YJ-T1-11T (98.0 %), Gemmobacter fontiphilus JS43T (97.8 %), Gemmobacter aquatilis DSM 3857T (97.5 %) and Gemmobacter lanyuensis Orc-4T (96.9 %). Additional phylogenomic analysis also indicated that strain HB-1T belongs to the genus Gemmobacter. The draft genome of strain HB-1T had a total length of 4.23 Mbp and contained 4071 protein-coding genes. The average nucleotide identity values between the genomes of strain HB-1T and the three most-related type strains ranged from 77.5 to 78.1 %. The DNA G+C content of strain HB-1T was 63.7 mol%. The novel strain grew at 10-37 °C, pH 5-10 and with 0-2 % NaCl. Oxidase and catalase activities were positive. Cells were 0.3-0.4 µm wide, 3.0-7.0 µm long and usually found in pairs or chains of cells. The major respiratory quinone of strain HB-1T was Q-10 (90 %), with a minor amount of Q-9 (10 %). The major fatty acids were C18 : 1 ω7c (54.6 %) and C16 : 0 (18.2 %). On the basis of phenotypic, phylogenetic and chemotaxonomic data, strain HB-1T (=DSM 109828T=ATCC TSD-211T) is considered to represent a novel species of the genus Gemmobacter, for which the name Gemmobacter serpentinus sp. nov. is proposed.


Asunto(s)
Alimentación Animal/microbiología , Filogenia , Rhodobacteraceae/clasificación , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/genética , Ácidos Grasos/química , Kansas , ARN Ribosómico 16S/genética , Rhodobacteraceae/aislamiento & purificación , Análisis de Secuencia de ADN , Ubiquinona/análogos & derivados , Ubiquinona/química
9.
Mol Cell Proteomics ; 17(9): 1803-1823, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29959188

RESUMEN

Chronic physical restraint stress increases oxidative stress in the brain, and dysregulation of oxidative stress can be one of the causes of major depressive disorder. To understand the underlying mechanisms, we undertook a systematic proteomic analysis of hippocampus in a chronic restraint stress mouse model of depression. Combining two-dimensional gel electrophoresis (2D-PAGE) for protein separation with nanoUPLC-ESI-q-TOF tandem mass spectrometry, we identified sixty-three protein spots that changed in the hippocampus of mice subjected to chronic restraint stress. We identified and classified the proteins that changed after chronic stress, into three groups respectively functioning in neural plasticity, metabolic processes and protein aggregation. Of these, 5 proteins including ubiquitin C-terminal hydrolase L1 (UCH-L1), dihydropyrimidinase-related protein 2 (DPYL2), haloacid dehalogenase-like hydrolase domain-containing protein 2 (HDHD2), actin-related protein 2/3 complex subunit 5 (ARPC5) and peroxiredoxin-2 (PRDX2), showed pI shifts attributable to post-translational modifications. Further analysis indicated that UCH-L1 underwent differential oxidations of 2 cysteine residues following chronic stress. We investigated whether the oxidized form of UCH-L1 plays a role in stressed hippocampus, by comparing the effects of UCH-L1 and its Cys mutants on hippocampal cell line HT-22 in response to oxidative stress. This study demonstrated that UCH-L1 wild-type and cysteine to aspartic acid mutants, but not its cysteine to serine mutants, afforded neuroprotective effects against oxidative stress; there were no discernible differences between wild-type UCH-L1 and its mutants in the absence of oxidative stress. These findings suggest that cysteine oxidative modifications of UCH-L1 in the hippocampus play key roles in neuroprotection against oxidative stress caused in major depressive disorder.


Asunto(s)
Cisteína/metabolismo , Depresión/metabolismo , Hipocampo/metabolismo , Neuroprotección , Procesamiento Proteico-Postraduccional , Proteómica , Estrés Psicológico/complicaciones , Ubiquitina Tiolesterasa/metabolismo , Animales , Línea Celular , Supervivencia Celular/efectos de los fármacos , Enfermedad Crónica , Modelos Animales de Enfermedad , Silenciador del Gen/efectos de los fármacos , Peróxido de Hidrógeno/toxicidad , Cinética , Masculino , Ratones Endogámicos C57BL , Mutación/genética , Oxidación-Reducción , Estrés Oxidativo/efectos de los fármacos , Restricción Física
10.
Health Commun ; 35(7): 793-803, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-30924694

RESUMEN

This study examined how the interplay between message framing and social norms affected college students' responses to advertisements and their intentions to drink responsibly, using the lens of deviance regulation theory. The results showed more favorable responses to gain-framed messaging than loss-framed messaging, especially among college students who believed that most of their peers use alcohol irresponsibly (i.e., they observed an unhealthy social norm). This study also investigated how the moderating effects of social norms on message framing differ depending on the level of individual alcohol consumption, and found that the deviance regulation effects on intention to drink responsibly were mitigated among heavy drinkers. The findings suggest strategic potential for using messaging, social context, and individual factors to develop effective campaigns that promote responsible drinking.


Asunto(s)
Normas Sociales , Universidades , Consumo de Bebidas Alcohólicas , Humanos , Intención , Estudiantes
11.
J Biol Chem ; 292(31): 12801-12812, 2017 08 04.
Artículo en Inglés | MEDLINE | ID: mdl-28592492

RESUMEN

When cells are exposed to heat shock and various other stresses, heat shock factor 1 (HSF1) is activated, and the heat shock response (HSR) is elicited. To better understand the molecular regulation of the HSR, we used 2D-PAGE-based proteome analysis to screen for heat shock-induced post-translationally modified cellular proteins. Our analysis revealed that two protein spots typically present on 2D-PAGE gels and containing heterogeneous nuclear ribonucleoprotein K (hnRNP K) with trioxidized Cys132 disappeared after the heat shock treatment and reappeared during recovery, but the total amount of hnRNP K protein remained unchanged. We next tested whether hnRNP K plays a role in HSR by regulating HSF1 and found that hnRNP K inhibits HSF1 activity, resulting in reduced expression of hsp70 and hsp27 mRNAs. hnRNP K also reduced binding affinity of HSF1 to the heat shock element by directly interacting with HSF1 but did not affect HSF1 phosphorylation-dependent activation or nuclear localization. hnRNP K lost its ability to induce these effects when its Cys132 was substituted with Ser, Asp, or Glu. These findings suggest that hnRNP K inhibits transcriptional activity of HSF1 by inhibiting its binding to heat shock element and that the oxidation status of Cys132 in hnRNP K is critical for this inhibition.


Asunto(s)
Proteínas de Unión al ADN/antagonistas & inhibidores , Regulación de la Expresión Génica , Proteínas de Choque Térmico HSP27/antagonistas & inhibidores , Proteínas HSP70 de Choque Térmico/antagonistas & inhibidores , Ribonucleoproteína Heterogénea-Nuclear Grupo K/metabolismo , Procesamiento Proteico-Postraduccional , Elementos de Respuesta , Factores de Transcripción/antagonistas & inhibidores , Sustitución de Aminoácidos , Animales , Línea Celular Tumoral , Cistina/metabolismo , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Perfilación de la Expresión Génica , Células HEK293 , Proteínas de Choque Térmico HSP27/genética , Proteínas de Choque Térmico HSP27/metabolismo , Proteínas HSP70 de Choque Térmico/genética , Proteínas HSP70 de Choque Térmico/metabolismo , Factores de Transcripción del Choque Térmico , Proteínas de Choque Térmico , Ribonucleoproteína Heterogénea-Nuclear Grupo K/antagonistas & inhibidores , Ribonucleoproteína Heterogénea-Nuclear Grupo K/genética , Calor/efectos adversos , Humanos , Ratones , Chaperonas Moleculares , Mutación , Oxidación-Reducción , Interferencia de ARN , ARN Mensajero/metabolismo , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Ribonucleoproteínas/antagonistas & inhibidores , Ribonucleoproteínas/genética , Ribonucleoproteínas/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
12.
Int J Syst Evol Microbiol ; 68(2): 582-588, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29300161

RESUMEN

A Gram-stain-negative, motile by gliding, rod-shaped, aerobic bacterium, designated 15J6-3T6T, was isolated from a soil sample collected from Jeju Island, South Korea, and characterized taxonomically using a polyphasic approach. Comparative 16S rRNA gene sequence analysis showed that strain 15J6-3T6T belongs to the family Cytophagaceae and is related to Larkinella harenae 15J9-9T (93.9 % similarity), Larkinella arboricola Z0532T (93.6 %), Larkinella bovis M2TB15T (93.3 %), and Larkinella insperata LMG 22510T (93.3 %). The DNA G+C content of strain 15J6-3T6T was 50.6 mol%. The detection of phosphatidylethanolamine and an unidentified polar lipid as major polar lipids, menaquinone-7 as the predominant quinone, and C16 : 1ω5c, iso-C15 : 0, and iso-C17 : 0 3-OH as the major fatty acids also supports the affiliation of the isolate to the genus Larkinella. Based on its phenotypic properties and phylogenetic distinctiveness, we propose that strain 15J6-3T6T should be classified in the genus Larkinella as a representative of a novel species, for which the name Larkinella knui sp. nov. is proposed. The type strain is 15J6-3T6T (=KCTC 42998T=JCM 31989T).


Asunto(s)
Cytophagaceae/clasificación , Filogenia , Microbiología del Suelo , Técnicas de Tipificación Bacteriana , Composición de Base , Cytophagaceae/genética , Cytophagaceae/aislamiento & purificación , ADN Bacteriano/genética , Ácidos Grasos/química , Fosfatidiletanolaminas/química , ARN Ribosómico 16S/genética , República de Corea , Análisis de Secuencia de ADN , Vitamina K 2/análogos & derivados , Vitamina K 2/química
13.
Curr Microbiol ; 75(3): 328-335, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29116346

RESUMEN

A Gram-stain-negative, non-motile, rod-shaped, aerobic bacterial strain, designated S7-4-1T, was isolated from soil in Gyeongsangnam-do, South Korea and characterized using a polyphasic approach to determine its taxonomic position. Phylogenic analysis based on the 16S rRNA gene sequence showed that strain S7-4-1T belonged to the family Cytophagaceae and was most closely related to Spirosoma fluviale MSd3T (96.2%), 'Spirosoma radiotolerans' DG5A (96.0%), Spirosoma pulveris JSH5-14T (95.9%), and Spirosoma linguale DSM 74T (95.8%). The G+C content of the genomic DNA of the isolate was 49.0 mol%. The strain contained summed feature 3 (C16:1 ω7c/C16:1 ω6c; 41.0%), C16:1 ω5c (24.9%), and C15:0 iso (9.3%) as the major fatty acids, menaquinone MK-7 as the predominant respiratory quinone, and phosphatidylethanolamine and an unidentified aminophospholipid as the main polar lipids, which supported its affiliation with the genus Spirosoma. The results of physiological and biochemical tests allowed the genotypic and phenotypic differentiation of the isolate from recognized Spirosoma species. On the basis of its phenotypic properties, genotypic distinctiveness, and chemotaxonomic features, strain S7-4-1T represents a novel species of the genus Spirosoma, for which the name Spirosoma humi sp. nov. is proposed. The type strain is S7-4-1T (= KCTC 52729T = JCM 32132T).


Asunto(s)
Cytophagaceae/aislamiento & purificación , Microbiología del Suelo , Técnicas de Tipificación Bacteriana , Composición de Base , Cytophagaceae/clasificación , Cytophagaceae/genética , Cytophagaceae/metabolismo , ADN Bacteriano , Ácidos Grasos/química , Ácidos Grasos/metabolismo , Filogenia , ARN Ribosómico 16S/genética , República de Corea
14.
Curr Microbiol ; 75(4): 492-498, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29209820

RESUMEN

The taxonomic position of bacterial strain, designated 15J9-4T, recovered from a beach soil sample on Jeju Island, South Korea, was established using a polyphasic approach. Strain 15J9-4T was assigned to phylum Bacteroidetes within the family Cytophagaceae based on 16S rRNA gene similarities. The closest phylogenetic relatives with validly published names were Spirosoma panaciterrae Gsoil 1519T (94.2% similarity) and Spirosoma luteolum 16F6ET (94.1%). Cells were rod-shaped, Gram-stain-negative, and non-motile. The isolate grew on NA, R2A, TSA, and LB agar. The temperature limits for growth were 10 and 30 °C with an optimum at 25 °C and the pH range was 7-8. Menaquinone MK-7 was the predominant respiratory quinone. The major cellular fatty acids comprised summed feature 3 (C16:1 ω6c/C16:1 ω7c, 30.2%), C16:1 ω5c (22.2%), iso C15:0 (12.9%), and C16:0 (8.8%). Phosphatidylethanolamine was identified as the major polar lipid. The G+C content of the genomic DNA was 48.4 mol%. The results obtained from the polyphasic analyses allowed for the genotypic and phenotypic differentiation of strain 15J9-4T from recognized Spirosoma species. Therefore, the isolate is considered to represent a novel species in the genus Spirosoma, for which the name Spirosoma terrae sp. nov. is proposed. The type strain is 15J9-4T (= KCTC 52035T = JCM 31994T).


Asunto(s)
Cytophagaceae/aislamiento & purificación , Microbiología del Suelo , Técnicas de Tipificación Bacteriana , Composición de Base , Cytophagaceae/clasificación , Cytophagaceae/genética , Cytophagaceae/metabolismo , ADN Bacteriano/genética , Ácidos Grasos/química , Ácidos Grasos/metabolismo , Filogenia , ARN Ribosómico 16S/genética , República de Corea , Suelo/química
15.
Curr Microbiol ; 75(2): 179-185, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29022066

RESUMEN

A Gram-stain-negative, non-motile, non-spore-forming, rod-shaped, aerobic bacterium, designated 15J8-9T, was isolated from a sandy beach in Jeju Island, South Korea. The isolate was able to grow between 10 and 30 °C, pH 5-8, and in presence of 0-1% (w/v) NaCl. Based on 16S rRNA gene phylogenetic analysis, the novel strain was closely related to members of the genus Spirosoma (96.1-90.9% similarities) and showed highest sequence similarity to Spirosoma panaciterrae DSM 21099T (96.1%). The G + C content of the genomic DNA of strain 15J8-9T was 45.1 mol%. The isolate contained menaquinone MK-7 as the predominant respiratory quinone, phosphatidylethanolamine as the major polar lipid, and summed feature 3 (C16:1 ω6c/C16:1 ω7c; 28.0%), C16:1 ω5c (23.4%), iso-C15:0 (13.5%), and C16:0 (11.5%) as the major fatty acids that supported the affiliation of strain 15J8-9T to the genus Spirosoma. The isolate could be differentiated clearly from recognized Spirosoma species on the basis of several phenotypic, genotypic and chemotaxonomic features. Therefore, strain 15J8-9T is considered to represent a novel species of the genus the genus Spirosoma, for which the name Spirosoma harenae sp. nov. is proposed. The type strain is 15J8-9T (= KCTC 52030T = JCM 31993T).


Asunto(s)
Cytophagaceae/clasificación , Cytophagaceae/aislamiento & purificación , Microbiología del Suelo , Aerobiosis , Composición de Base , Análisis por Conglomerados , Cytophagaceae/genética , Cytophagaceae/fisiología , Citosol/química , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Ácidos Grasos/análisis , Concentración de Iones de Hidrógeno , Corea (Geográfico) , Fosfolípidos/análisis , Filogenia , Quinonas/análisis , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Cloruro de Sodio/metabolismo , Temperatura , Vitamina K 2/análisis
16.
Environ Microbiol ; 19(6): 2258-2271, 2017 06.
Artículo en Inglés | MEDLINE | ID: mdl-28276129

RESUMEN

Perennially ice-covered lakes in the McMurdo Dry Valleys, Antarctica, are chemically stratified with depth and have distinct biological gradients. Despite long-term research on these unique environments, data on the structure of the microbial communities in the water columns of these lakes are scarce. Here, we examined bacterial diversity in five ice-covered Antarctic lakes by 16S rRNA gene-based pyrosequencing. Distinct communities were present in each lake, reflecting the unique biogeochemical characteristics of these environments. Further, certain bacterial lineages were confined exclusively to specific depths within each lake. For example, candidate division WM88 occurred solely at a depth of 15 m in Lake Fryxell, whereas unknown lineages of Chlorobi were found only at a depth of 18 m in Lake Miers, and two distinct classes of Firmicutes inhabited East and West Lobe Bonney at depths of 30 m. Redundancy analysis revealed that community variation of bacterioplankton could be explained by the distinct conditions of each lake and depth; in particular, assemblages from layers beneath the chemocline had biogeochemical associations that differed from those in the upper layers. These patterns of community composition may represent bacterial adaptations to the extreme and unique biogeochemical gradients of ice-covered lakes in the McMurdo Dry Valleys.


Asunto(s)
Bacterias/clasificación , Bacterias/genética , Cubierta de Hielo/microbiología , Lagos/microbiología , Regiones Antárticas , Secuencia de Bases , Biodiversidad , ARN Ribosómico 16S/genética
17.
Int J Syst Evol Microbiol ; 67(5): 1206-1211, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28086076

RESUMEN

A Gram-stain-negative, non-motile, non-spore-forming, rod-shaped, aerobic bacterial strain, designated 16F3PT, was isolated from the Han River, South Korea, and characterized taxonomically using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences revealed 16F3PT to be within the genus Hymenobacter, and most closely related to Hymenobacterchitinivorans Txc1T (98.62 %) and Hymenobacterelongatus VUG-A112T (98.46 %). The phylogenetic distance from other species of the genus Hymenobacter with validly published names was greater than 4 % (i.e. sequence similarity was less than 96.0 %). Chemotaxonomic data also supported the classification of strain 16F3PT within the genus Hymenobacter. C16 : 0 (19.8 %), summed feature 3 (C16 : 1ω7c/C16 : 1ω6c; 15.4 %) and iso-C15 : 0 (13.0 %) were the major fatty acids, MK-7 was the predominant respiratory quinone, and phosphatidylethanolamine was the major polar lipid. The G+C content of the genomic DNA of strain 16F3PT was 61.9 mol%. DNA-DNA hybridization experiments showed that the values for DNA-DNA relatedness between strain 16F3PT and the phylogenetically closest neighbours were below 19 %. On the basis of its phenotypic properties and phylogenetic distinctiveness, strain 16F3PT represents a novel species of the genus Hymenobacter, for which the name Hymenobacter aquaticus sp. nov. is proposed. The type strain is 16F3PT (=KCTC 52194T=JCM 31653T).


Asunto(s)
Cytophagaceae/clasificación , Cytophagaceae/efectos de la radiación , Filogenia , Ríos/microbiología , Técnicas de Tipificación Bacteriana , Composición de Base , Cytophagaceae/aislamiento & purificación , ADN Bacteriano/genética , Ácidos Grasos/química , Hibridación de Ácido Nucleico , Fosfatidiletanolaminas/química , ARN Ribosómico 16S/genética , República de Corea , Análisis de Secuencia de ADN , Vitamina K 2/análogos & derivados , Vitamina K 2/química
18.
Int J Syst Evol Microbiol ; 67(8): 2660-2664, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28809148

RESUMEN

A Gram-stain-negative, aerobic, rod-shaped, non-motile and pale yellow-pigmented bacterial strain, designated as HY03T, was isolated from mountain soil. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain HY03T belonged to the family Chitinophagaceae in the phylum Bacteroidetes and was most closely related to Flaviaesturariibacter amylovorans GCR0105T at a similarity of 95.4 %. The genomic DNA G+C content of strain HY03T was 43.2 mol%. The major fatty acids of the isolate were iso-C15 : 0, iso-C15 : 1 G and iso-C17 : 0 3-OH. The polar lipid profile of strain HY03T consisted of the major compound phosphatidylethanolamine and moderate amounts of an unknown aminophospholipid, unknown phospholipids and unknown lipids. The predominant respiratory quinone was menaquinone 7 (MK-7). Phylogenetic, genotypic, phenotypic and chemotaxonomic characteristics indicated that strain HY03T represents a novel species within the genus Flaviaesturariibacter, for which the name Flaviaesturariibacter terrae sp. nov. is proposed. The type strain is HY03T (=KCTC 52511T=JCM 31723T).


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 , Fosfolípidos/química , Pigmentación , ARN Ribosómico 16S/genética , República de Corea , Análisis de Secuencia de ADN , Vitamina K 2/análogos & derivados , Vitamina K 2/química
19.
Int J Syst Evol Microbiol ; 67(8): 2922-2927, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28820126

RESUMEN

Strain HY02T was isolated from a soil sample collected at Namyangju-si, Gyeonggi-do, Republic of Korea. Cells of this strain were observed to be Gram-stain-negative, short and rod-shaped. Colonies were red in colour. A 16S rRNA gene sequence analysis identified this strain as a member of the genus Adhaeribacter in the family Cytophagaceae, with the highest level of 16S rRNA gene sequence similarity to Adhaeribacter terreus DNG6T (98.08 %). This strain was positive for oxidase but negative for catalase activity and acid production from glucose. Growth of strain HY02T was observed at 15-30 °C, pH 7-8 and in the presence of 0-1 % NaCl. The isolate contained MK-7 as the predominant respiratory quinone, and C18 : 0, iso-C15 : 0, summed feature 4 (anteiso-C17 : 1 B/iso-C17 : 1 I) and C16 : 0 were the major fatty acids. The major polar lipid was phosphatidylethanolamine. The genomic DNA G+C content of strain HY02T was 44.0 mol%. Phenotypic and chemotaxonomic data supported the affiliation of strain HY02T with the genus Adhaeribacter. However, strain HY02T exhibited a relatively low level of DNA-DNA relatedness with A. terreus(16.3±3.5 %). Based on its phenotypic and genotypic properties, together with its phylogenetic distinctiveness, strain HY02T should be considered a representative of a novel species in the genus Adhaeribacter, for which the name Adhaeribacter terrae sp. nov. is proposed. The type strain is HY02T (=KCTC 52512T=JCM 31652T).


Asunto(s)
Cytophagaceae/clasificación , Filogenia , Microbiología del Suelo , Técnicas de Tipificación Bacteriana , Composición de Base , Cytophagaceae/genética , Cytophagaceae/aislamiento & purificación , ADN Bacteriano/genética , Ácidos Grasos/química , Hibridación de Ácido Nucleico , Fosfatidiletanolaminas/química , ARN Ribosómico 16S/genética , República de Corea , Análisis de Secuencia de ADN , Vitamina K 2/análogos & derivados , Vitamina K 2/química
20.
Int J Syst Evol Microbiol ; 67(10): 3759-3764, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28879840

RESUMEN

Strain 15J11-11T was isolated from soil collected at the seashore and was Gram-staining-negative, short-rod-shaped, gliding and pale-pink pigmented. Flexirubin-type pigments were absent. The isolate grew at a temperature range of 15 to 30 °C and a pH range of 7 to 8. Comparative 16S rRNA gene sequence studies showed that strain 15J11-11T belonged to the genus Larkinella within the phylum Bacteroidetes and was most closely related to Larkinella arboricola Z0532T (95.6 %), Larkinella bovis M2TB15T (95.4 %), and Larkinella insperata LMG 22510T (95.2 %). The genomic DNA G+C content of strain 15J11-11T was 53.2 mol%. The strain contained phosphatidylethanolamine, phosphatidylserine, an unidentified aminophospholipid and two unidentified polar lipids as the major polar lipids; menaquinone-7 as the predominant quinone and C16 : 1ω5c, iso-C15 : 0 and iso-C17 : 0 3-OH as the major fatty acids which supported the affiliation of strain 15J11-11T to the genus Larkinella. Based on its phenotypic properties and phylogenetic distinctiveness, strain 15J11-11T represents a novel species of the genus Larkinella, for which the name Larkinella ripae sp. nov. is proposed. The type strain is 15J11-11T (=KCTC 42996T=JCM 31657T).


Asunto(s)
Cytophagaceae/clasificación , Filogenia , Microbiología del Suelo , Técnicas de Tipificación Bacteriana , Composición de Base , Cytophagaceae/genética , Cytophagaceae/aislamiento & purificación , ADN Bacteriano/genética , Ácidos Grasos/química , Fosfolípidos/química , Pigmentación , ARN Ribosómico 16S/genética , República de Corea , Análisis de Secuencia de ADN , Vitamina K 2/análogos & derivados , Vitamina K 2/química
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA