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Complete genome sequence of Delftia tsuruhatensis strain HA60 isolated from a commercial hydroxyapatite nano-particle product (nano-hydroxyapatite). Microbiol Resour Announc 2024:e0017124. [PMID: 38700346 DOI: 10.1128/mra.00171-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Accepted: 04/22/2024] [Indexed: 05/05/2024] Open
Abstract
Delftia tsuruhatensis is a Gram-negative rod-shaped aerobic bacterium with environmental remediation functions. D. tsuruhatensis strain HA60 was isolated from a commercial nano-particle product, nano-hydroxyapatite. We report that the genome of D. tsuruhatensis strain HA60 has a circular genome of 6,922,195 base pairs with a G+C content of 66.45%.
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2
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Small-scale spatial beta diversity of bacteria in the mixed upper layer of a lake. Environ Microbiol 2023; 25:1847-1859. [PMID: 37173811 DOI: 10.1111/1462-2920.16399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 04/27/2023] [Indexed: 05/15/2023]
Abstract
Bacterial community composition among individual, experimentally generated 'lake snow' particles may be highly variable. Since such aggregates are seasonally abundant in the mixed upper layer of lakes, we hypothesized that particle-attached (PA) bacteria disproportionally contribute to the small-scale spatial beta diversity of pelagic communities. Community composition was analysed in sets of small (10 mL) samples collected from a pre-alpine lake in May, July and October 2018. Bacteria were classified as free-living (FL) or PA depending on their presence in large, 5-μm pre-filtered reference samples. FL exhibited clear seasonal differences in community composition and assembly. They were spatially uniform in May and July, and only a few FL taxa exhibited significant spatial variability. Spatial heterogeneity of FL in October was caused by high alpha and beta diversity of rare taxa, many with a presumably 'tychoplanktic' (alternating attached and free-living) lifestyle. The spatial beta diversity of PA was always high, and only about 10% of their seasonal richness was present in any single sample. Thus, most compositional variability of pelagic bacteria at spatial scales of cm to m either directly or indirectly originated from PA. On a functional level, this genotypic heterogeneity might affect the spatial distribution of rare metabolic traits.
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Comparisons of the Oral Microbiota from Seven Species of Wild Venomous Snakes in Taiwan Using the High-Throughput Amplicon Sequencing of the Full-Length 16S rRNA Gene. BIOLOGY 2023; 12:1206. [PMID: 37759605 PMCID: PMC10525742 DOI: 10.3390/biology12091206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 08/26/2023] [Accepted: 09/02/2023] [Indexed: 09/29/2023]
Abstract
A venomous snake's oral cavity may harbor pathogenic microorganisms that cause secondary infection at the wound site after being bitten. We collected oral samples from 37 individuals belonging to seven species of wild venomous snakes in Taiwan, including Naja atra (Na), Bungarus multicinctus (Bm), Protobothrops mucrosquamatus (Pm), Trimeresurus stejnegeri (Ts), Daboia siamensis (Ds), Deinagkistrodon acutus (Da), and alpine Trimeresurus gracilis (Tg). Bacterial species were identified using full-length 16S rRNA amplicon sequencing analysis, and this is the first study using this technique to investigate the oral microbiota of multiple Taiwanese snake species. Up to 1064 bacterial species were identified from the snake's oral cavities, with 24 pathogenic and 24 non-pathogenic species among the most abundant ones. The most abundant oral bacterial species detected in our study were different from those found in previous studies, which varied by snake species, collection sites, sampling tissues, culture dependence, and analysis methods. Multivariate analysis revealed that the oral bacterial species compositions in Na, Bm, and Pm each were significantly different from the other species, whereas those among Ts, Ds, Da, and Tg showed fewer differences. Herein, we reveal the microbial diversity in multiple species of wild snakes and provide potential therapeutic implications regarding empiric antibiotic selection for wildlife medicine and snakebite management.
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The Relationship between Brachionus calyciflorus-Associated Bacterial and Bacterioplankton Communities in a Subtropical Freshwater Lake. Animals (Basel) 2022; 12:ani12223201. [PMID: 36428428 PMCID: PMC9686566 DOI: 10.3390/ani12223201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 11/12/2022] [Accepted: 11/16/2022] [Indexed: 11/22/2022] Open
Abstract
Zooplankton bodies are organic-rich micro-environments that support fast bacterial growth. Therefore, the abundance of zooplankton-associated bacteria is much higher than that of free-living bacteria, which has profound effects on the nutrient cycling of freshwater ecosystems. However, a detailed analysis of associated bacteria is still less known, especially the relationship between those bacteria and bacterioplankton. In this study, we analyzed the relationships between Brachionus calyciflorus-associated bacterial and bacterioplankton communities in freshwater using high-throughput sequencing. The results indicated that there were significant differences between the two bacterial communities, with only 29.47% sharing OTUs. The alpha diversity of the bacterioplankton community was significantly higher than that of B. calyciflorus-associated bacteria. PCoA analysis showed that the bacterioplankton community gathered deeply, while the B. calyciflorus-associated bacterial community was far away from the whole bacterioplankton community, and the distribution was relatively discrete. CCA analysis suggested that many environmental factors (T, DO, pH, TP, PO43-, NH4+, and NO3-) regulated the community composition of B. calyciflorus-associated bacteria, but the explanatory degree of variability was only 37.80%. High-throughput sequencing revealed that Raoultella and Delftia in Proteobacteria were the dominant genus in the B. calyciflorus-associated bacterial community, and closely related to the biodegradation function. Moreover, several abundant bacterial members participating in carbon and nitrogen cycles were found in the associated bacterial community by network analysis. Predictive results from FAPROTAX showed that the predominant biogeochemical cycle functions of the B. calyciflorus-associated bacterial community were plastic degradation, chemoheterotrophy, and aerobic chemoheterotrophy. Overall, our study expands the current understanding of zooplankton-bacteria interaction and promotes the combination of two different research fields.
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Phylogenomic analysis of the genus Delftia reveals distinct major lineages with ecological specializations. Microb Genom 2022; 8:mgen000864. [PMID: 36107145 PMCID: PMC9676026 DOI: 10.1099/mgen.0.000864] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 06/15/2022] [Indexed: 04/01/2024] Open
Abstract
Delftia is a diverse betaproteobacterial genus with many strains having agricultural and industrial relevance, including plant-growth promotion, bioremediation of hydrocarbon-contaminated soils, and heavy metal immobilization. Delftia spp. are broadly distributed in the environment, and have been isolated from plant hosts as well as healthy and diseased animal hosts, yet the genetic basis of this ecological versatility has not been characterized. Here, we present a phylogenomic comparison of published Delftia genomes and show that the genus is divided into two well-supported clades: one 'Delftia acidovorans' clade with isolates from soils and plant rhizospheres, and a second 'Delftia lacustris and Delftia tsuruhatensis' clade with isolates from humans and sludge. The pan-genome inferred from 61 Delftia genomes contained over 28 000 genes, of which only 884 were found in all genomes. Analysis of industrially relevant functions highlighted the ecological versatility of Delftia and supported their role as generalists.
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Changes in Ambient Bacterial Community in Northern Taiwan during Long-Range Transport: Asian Dust Storm and Frontal Pollution. ATMOSPHERE 2022. [DOI: 10.3390/atmos13050841] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Long-range transport (LRT) can carry air pollutants to downwind areas. However, studies about the impacts of LRT on bacterial communities are few. This study investigated the influence of Asian dust storms (ADS) and frontal pollution (FP) on bacterial communities in ambient air using next-generation sequencing (NGS) and Terminal Restriction Fragment Length Polymorphism (T-RFLP). Air samples were collected at Cape Fugui (CF) and National Taiwan University (NTU) in northern Taiwan before (or background days), during, and after LRTs from November 2013 to March 2015. The richness, H index, and evenness increased during FPs and then decreased after FPs. During and after ADS and FP, the prevalence of the phylum Proteobacteria decreased, but that of Firmicutes increased. The dominant class of Proteobacteria changed from Alphaproteobacteria on background days to Betaproteobacteria during LRTs. At the genus level, the high abundance of Ralstonia and Bacillus during FP and Clostridium during ADS were detected at both locations. Additionally, Ralstonia was dominant at CF during ADS. In conclusion, FP and ADS both changed the bacterial community. The indicator genus was Clostridium and Ralstonia for ADS as well as Bacillus and Ralstonia for FP. Given the potential health threats posed by the bioaerosols transported, people should avoid outdoor activities during LRTs.
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Isolation and identification of Delftia lacustris Strain-MS3 as a novel and efficient adsorbent for lead biosorption: Kinetics and thermodynamic studies, optimization of operating variables. Biochem Eng J 2021. [DOI: 10.1016/j.bej.2021.108091] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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First Identification of IMP-1 Metallo-β-Lactamase in Delftia tsuruhatensis Strain CRS1243 Isolated From a Clinical Specimen. Ann Lab Med 2021; 41:436-438. [PMID: 33536365 PMCID: PMC7884188 DOI: 10.3343/alm.2021.41.4.436] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 09/23/2020] [Accepted: 01/04/2021] [Indexed: 12/31/2022] Open
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Genomic Analysis of Delftia tsuruhatensis Strain TR1180 Isolated From A Patient From China With In4-Like Integron-Associated Antimicrobial Resistance. Front Cell Infect Microbiol 2021; 11:663933. [PMID: 34222039 PMCID: PMC8248536 DOI: 10.3389/fcimb.2021.663933] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 05/31/2021] [Indexed: 12/04/2022] Open
Abstract
Delftia tsuruhatensis has become an emerging pathogen in humans. There is scant information on the genomic characteristics of this microorganism. In this study, we determined the complete genome sequence of a clinical D. tsuruhatensis strain, TR1180, isolated from a sputum specimen of a female patient in China in 2019. Phylogenetic and average nucleotide identity analysis demonstrated that TR1180 is a member of D. tsuruhatensis. TR1180 exhibited resistance to β-lactam, aminoglycoside, tetracycline and sulphonamide antibiotics, but was susceptible to phenicols, fluoroquinolones and macrolides. Its genome is a single, circular chromosome measuring 6,711,018 bp in size. Whole-genome analysis identified 17 antibiotic resistance-related genes, which match the antimicrobial susceptibility profile of this strain, as well as 24 potential virulence factors and a number of metal resistance genes. Our data showed that Delftia possessed an open pan-genome and the genes in the core genome contributed to the pathogenicity and resistance of Delftia strains. Comparative genomics analysis of TR1180 with other publicly available genomes of Delftia showed diverse genomic features among these strains. D. tsuruhatensis TR1180 harbored a unique 38-kb genomic island flanked by a pair of 29-bp direct repeats with the insertion of a novel In4-like integron containing most of the specific antibiotic resistance genes within the genome. This study reports the findings of a fully sequenced genome from clinical D. tsuruhatensis, which provide researchers and clinicians with valuable insights into this uncommon species.
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Identification of Microorganisms from Several Surfaces by MALDI-TOF MS: P. aeruginosa Is Leading in Biofilm Formation. Microorganisms 2021; 9:microorganisms9050992. [PMID: 34064414 PMCID: PMC8147854 DOI: 10.3390/microorganisms9050992] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 04/29/2021] [Accepted: 05/02/2021] [Indexed: 01/10/2023] Open
Abstract
New ecological trends and changes in consumer behavior are known to favor biofilm formation in household appliances, increasing the need for new antimicrobial materials and surfaces. Their development requires laboratory-cultivated biofilms, or biofilm model systems (BMS), which allow for accelerated growth and offer better understanding of the underlying formation mechanisms. Here, we identified bacterial strains in wildtype biofilms from a variety of materials from domestic appliances using matrix-assisted laser desorption/ionization-time of flight mass spectroscopy (MALDI-TOF-MS). Staphylococci and pseudomonads were identified by MALDI-TOF-MS as the main genera in the habitats and were analyzed for biofilm formation using various in vitro methods. Standard quantitative biofilm assays were combined with scanning electron microscopy (SEM) to characterize biofilm formation. While Pseudomonas putida, a published lead germ, was not identified in any of the collected samples, Pseudomonas aeruginosa was found to be the most dominant biofilm producer. Water-born Pseudomonads were dominantly found in compartments with water contact only, such as in detergent compartment and detergent enemata. Furthermore, materials in contact with the washing load are predominantly colonized with bacteria from the human.
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Bioremoval of graffiti using novel commercial strains of bacteria. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 756:144075. [PMID: 33280882 DOI: 10.1016/j.scitotenv.2020.144075] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Revised: 11/18/2020] [Accepted: 11/21/2020] [Indexed: 06/12/2023]
Abstract
Previous studies have provided evidence that bioremediation deals a novel approach to graffiti removal, thereby overcoming well-known limitations of current cleaning methods. In the present study eight bacteria aerobic, mesophilic and culturable from the American ATCC and the German DSMZ collections of microorganisms, some isolated from car paint waste, colored deposits in a pulp dryer and wastewater from dye works, were tested in the removal of silver and black graffiti spray paints using immersion strategies with glass slides. Absorbance at 600 nm and live/dead assays were performed to estimate bacterial density and activity in all samples. Also, pH and dissolved organic carbon (DOC) and inorganic carbon (DIC) measurements in the liquid media were made, as well as, thickness, colorimetric and infrared (FTIR) spectroscopy measurements in graffiti paint layers were used to evaluate the presence of the selected bacteria in the samples and the graffiti bioremoval capacity of bacteria. Data demonstrated that of the eight bacteria studied, Enterobacter aerogenes, Comamonas sp. and a mixture of Bacillus sp., Delftia lacustris, Sphingobacterium caeni, and Ochrobactrum anthropi were the most promising for bioremoval of graffiti. According to significant changes in FTIR spectra, indicating an alteration of the paint polymeric structure, coupled with the presence of a consistent quantity of live bacteria in the medium as well as a significant increase of DIC (a measure of metabolic activity) and a change in paint color.
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Biodegradation of erythromycin by Delftia lacustris RJJ-61 and characterization of its erythromycin esterase. J Basic Microbiol 2020; 61:55-62. [PMID: 33332633 DOI: 10.1002/jobm.202000613] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 12/01/2020] [Accepted: 12/05/2020] [Indexed: 11/06/2022]
Abstract
The residual erythromycin in fermentation waste can pollute the environment and threaten human health. However, there are no effective approaches to remedy this issue. In this study, an erythromycin-degrading bacterium named RJJ-61 was isolated and identified as a strain of Delftia lacustris based on morphological and phylogenetic analyses. The degradation ability of this strain was also evaluated; it could degrade 45.18% of erythromycin at 35°C in 120 h. Furthermore, the key degradation gene ereA was cloned from strain RJJ-61 and expressed in Escherichia coli BL21; the molecular weight of the expressed protein was ~45 kDa. The enzyme activity of EreA was 108.0 mU ml-1 at 35°C and pH 7.0. Finally, the EreA protein was used to degrade erythromycin from mycelial dregs and 50% diluted solution, and the removal rates in them were 41.42% and 69.78%, respectively. In summary, D. lacustris RJJ-61 is a novel erythromycin-degrading strain that has great potential to remove erythromycin pollutants from the environment.
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Ammonia oxidation and denitrification in a bio-anode single-chambered microbial electrolysis cell. BIORESOURCE TECHNOLOGY 2020; 310:123466. [PMID: 32388207 DOI: 10.1016/j.biortech.2020.123466] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 04/28/2020] [Accepted: 04/29/2020] [Indexed: 06/11/2023]
Abstract
In this study, anodic ammonia oxidation and denitrification were performed in single-chamber bioelectrochemical systems at a wide range of anodic potentials (-400 to +400 mV) versus Ag/AgCl. The low coulombic efficiencies (~30.84%) in reactors were mainly due to electrons being transferred to atmospheric oxygen through the electrode and reversal of the electrode. The removal efficiencies of acetate, ammonia, and total nitrogen were 100%, 100%, and 40.44% at +200 mV and 100%, 100%, and 50.24% at -200 mV, respectively. The nitrogen-removal mechanisms were nitrogen respiration/nitrate reduction at +200 mV and denitrification at -200 mV, and ammonia oxidation occurred by coupling with sulfate-reducing at -300 and -400 mV. Thauera, Comamonas, Alicycliphilus, Nitrosomonas, Desulforhabdus, Dethiosulfatibacter, and Desulfomicrobium were the dominant genera at the anode which participated in the nitrification/denitrification or sulfate-reducing processes. In summary, ammonia oxidation and denitrification could be coupled with carbon-removal or sulfur-reduction using a bio-anode with a suitable anodic potential.
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Catalyzing rapid discovery of gold-precipitating bacterial lineages with university students. PeerJ 2020; 8:e8925. [PMID: 32322441 PMCID: PMC7164421 DOI: 10.7717/peerj.8925] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 03/16/2020] [Indexed: 12/11/2022] Open
Abstract
Intriguing and potentially commercially useful microorganisms are found in our surroundings and new tools allow us to learn about their genetic potential and evolutionary history. Engaging students from different disciplines and courses in the search for microbes requires an exciting project with innovative but straightforward procedures and goals. Here we describe an interdisciplinary program to engage students from different courses in the sampling, identification and analysis of the DNA sequences of a unique yet common microbe, Delftia spp. A campus-wide challenge was created to identify the prevalence of this genus, able to precipitate gold, involving introductory level environmental and life science courses, upper-level advanced laboratory modules taken by undergraduate students (juniors and seniors), graduate students and staff from the campus. The number of participants involved allowed for extensive sampling while undergraduate researchers and students in lab-based courses participated in the sample processing and analyses, helping contextualize and solidify their learning of the molecular biology techniques. The results were shared at each step through publicly accessible websites and workshops. This model allows for the rapid discovery of Delftia presence and prevalence and is adaptable to different campuses and experimental questions.
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Polyphasic characterization of Delftia acidovorans ESM-1, a facultative methylotrophic bacterium isolated from rhizosphere of Eruca sativa. Saudi J Biol Sci 2019; 26:1262-1267. [PMID: 31516356 PMCID: PMC6733694 DOI: 10.1016/j.sjbs.2018.05.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 04/30/2018] [Accepted: 05/10/2018] [Indexed: 11/25/2022] Open
Abstract
In this study, one bacterial strain, ESM-1, was isolated from rhizosphere of Eruca sativa, growing in Al Hofouf, Saudia Arabia, after enrichment with methanol as a sole carbon and energy source in a batch culture. ESM-1 was characterized by a polyphasic approach. The strain was identified as Delftia acidovorans at similarity level of 99.9% of the 16S rRNA gene sequences. Results of the Biolog Gen III MicroPlate test system showed that strain ESM-1 reacted positively to 47 (50%) including the one-carbon compound formic acid, and partially positive to 6 (∼6.4%) out of the 94 different the traits examined. The total cellular fatty acids composition of the strain ESM-1 was (C16:1ω7c/C16:1ω6c) and C16:0) and matched that of Delftia acidovorans at a similarity index of 0.9, providing a robustness to the ESM-1 identification. Furthermore, ESM-1 displayed a complex polar lipid profile consisting of phosphatidylethanolamine, phosphatidylglycerol, glycolipid, aminolipid, in addition to uncharacterized lipids. The DNA G+C content of the strain was 66.6 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that the strain ESM1-1 was clearly clustered within the Delftia clade and constructed a monophyletic subcluster with Delftia acidovorans NBRC14950. The results addressed that ESM-1 is a facultative methylotrophic bacterium indigenous to Al Hofouf region and opens the door for potential biotechnological applications (e.g., bioremediation) of this strain, in future. Additionally, these findings assure that the total cellular fatty acid analysis and 16S rRNA gene are reliable tool for bacterial characterization and identification.
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Reduction of selenite to elemental Se(0) with simultaneous degradation of phenol by co-cultures of Phanerochaete chrysosporium and Delftia lacustris. J Microbiol 2019; 57:738-747. [PMID: 31376106 DOI: 10.1007/s12275-019-9042-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 03/17/2019] [Accepted: 03/27/2019] [Indexed: 11/26/2022]
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Bacteria with natural chemotaxis towards methanol revealed by chemotaxis fishing technique. Biosci Biotechnol Biochem 2019; 83:2163-2171. [PMID: 31272289 DOI: 10.1080/09168451.2019.1637715] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Motile bacteria often exhibit chemotaxis toward favorable compounds. However, the diversity of bacteria that are attracted to a given substance is largely unknown. This study aimed to reveal the diversity of bacteria with natural chemotaxis towards methanol. We tried to enrich environmental chemotactic bacteria using a glass capillary that is half-filled with methanol solidified with agarose as a trap ("chemotaxis fishing"). The pilot experiment using methanol-chemotactic Methylobacterium aquaticum strain 22A enriched the cells by 46-fold. The method was then applied to bacterial suspensions from paddy water and plants. Depending on the isolation sources and the methods of motility induction, methylotrophic bacteria were enriched 1.2-330-fold. The fished isolates belong to 32 species in 18 genera, mainly containing Acinetobacter, Methylobacterium and Pseudomonas species. Our chemotaxis fishing unveiled a part of diversity of the bacteria with natural chemotaxis towards methanol.
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Regional and Microenvironmental Scale Characterization of the Zostera muelleri Seagrass Microbiome. Front Microbiol 2019; 10:1011. [PMID: 31139163 PMCID: PMC6527750 DOI: 10.3389/fmicb.2019.01011] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 04/23/2019] [Indexed: 11/29/2022] Open
Abstract
Seagrasses are globally distributed marine plants that represent an extremely valuable component of coastal ecosystems. Like terrestrial plants, seagrass productivity and health are likely to be strongly governed by the structure and function of the seagrass microbiome, which will be distributed across a number of discrete microenvironments within the plant, including the phyllosphere, the endosphere and the rhizosphere, all different in physical and chemical conditions. Here we examined patterns in the composition of the microbiome of the seagrass Zostera muelleri, within six plant-associated microenvironments sampled across four different coastal locations in New South Wales, Australia. Amplicon sequencing approaches were used to characterize the diversity and composition of bacterial, microalgal, and fungal microbiomes and ultimately identify "core microbiome" members that were conserved across sampling microenvironments. Discrete populations of bacteria, microalgae and fungi were observed within specific seagrass microenvironments, including the leaves and roots and rhizomes, with "core" taxa found to persist within these microenvironments across geographically disparate sampling sites. Bacterial, microalgal and fungal community profiles were most strongly governed by intrinsic features of the different seagrass microenvironments, whereby microscale differences in community composition were greater than the differences observed between sampling regions. However, our results showed differing strengths of microbial preferences at the plant scale, since this microenvironmental variability was more pronounced for bacteria than it was for microalgae and fungi, suggesting more specific interactions between the bacterial consortia and the seagrass host, and potentially implying a highly specialized coupling between seagrass and bacterial metabolism and ecology. Due to their persistence within a given seagrass microenvironment, across geographically discrete sampling locations, we propose that the identified "core" microbiome members likely play key roles in seagrass physiology as well as the ecology and biogeochemistry of seagrass habitats.
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Microbial transformation of Se oxyanions in cultures of Delftia lacustris grown under aerobic conditions. J Microbiol 2019; 57:362-371. [PMID: 30900147 DOI: 10.1007/s12275-019-8427-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 11/20/2018] [Accepted: 11/26/2018] [Indexed: 12/29/2022]
Abstract
Delftia lacustris is reported for the first time as a selenate and selenite reducing bacterium, capable of tolerating and growing in the presence of ≥ 100 mM selenate and 25 mM selenite. The selenate reduction profiles of D. lacustris were investigated by varying selenate concentration, inoculum size, concentration and source of organic electron donor in minimal salt medium. Interestingly, the bacterium was able to reduce both selenate and selenite under aerobic conditions. Although considerable removal of selenate was observed at all concentrations investigated, D. lacustris was able to completely reduce 0.1 mM selenate within 96 h using lactate as the carbon source. Around 62.2% unaccounted selenium (unidentified organo-selenium compounds), 10.9% elemental selenium and 26.9% selenite were determined in the medium after complete reduction of selenate. Studies of the enzymatic activity of the cell fractions show that the selenite/selenate reducing enzymes were intracellular and independent of NADPH availability. D. lacustris shows an unique metabolism of selenium oxyanions to form elemental selenium and possibly also selenium ester compounds, thus a potential candidate for the remediation of selenium-contaminated wastewaters in aerobic environments. This novel finding will advance the field of bioremediation of selenium-contaminated sites and selenium bio-recovery and the production of potentially beneficial organic and inorganic reactive selenium species.
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A practical introduction to microbial molecular ecology through the use of isolation chips. Ecol Evol 2018; 8:12286-12298. [PMID: 30619545 PMCID: PMC6309002 DOI: 10.1002/ece3.4748] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 10/23/2018] [Accepted: 10/31/2018] [Indexed: 12/20/2022] Open
Abstract
In the context of antimicrobial resistance as one of the most serious issues faced globally by health providers, we explored a practical introduction to molecular microbial ecology. We designed field work and practical experiments for third year members of a 4 year undergraduate Masters Program, in which the students employed traditional and novel isolation techniques to identify antimicrobial activities from soil dwelling microorganisms. Students gained experience in isolating DNA from complex microbial communities, amplifying 16S rRNA genes and applied richness/diversity indices as well as principal coordinate analyses to the interpretation of the data they obtained from high throughput sequencing. Our results confirmed that isolation chips facilitate the growth of a greater diversity and different species subset from the complex soil microorganism community than traditional plate spreading techniques. However, rarefaction of 16S rRNA amplicon sequencing data showed that the majority of observed species in soil remain unculturable by current methods. Based on the written reports produced by the students carrying out the work, we concluded that the described protocols are robust and informative, that these activities provide a good practical introduction to the theories and practice of molecular ecology and can be easily deployed to groups of six or more students in a cost-effective manner.
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Inoculation of soil with cadmium-resistant bacterium Delftia sp. B9 reduces cadmium accumulation in rice (Oryza sativa L.) grains. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2018; 163:223-229. [PMID: 30055387 DOI: 10.1016/j.ecoenv.2018.07.081] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 07/18/2018] [Accepted: 07/20/2018] [Indexed: 06/08/2023]
Abstract
Bioremediation of heavy metal polluted soil using metal-resistant bacteria has received increasing attentions. In the present study, we isolated a heavy metal-resistant bacterial strain from a Cd-contaminated soil, and conducted pot experiments to evaluate the effect of bacterial inoculation in soil on soil Cd speciation, rice grain biomass and Cd accumulation. We find that the isolated bacterial strain is a Gram-negative bacterium, and named as Delftia sp. B9 based on the 16S rDNA gene sequence analysis. TEM-EDS manifests that Cd can be bioaccumulated inside cell, resulting in intracellular dissolution. The Cd contents of rice grain in the two rice cultivars (early and late rice) are all below the standard limit for Food Safety of People's Republic of China (0.2 mg/kg) after the treatment of both living and non-living cells. Non-living cells are more applicable than the use of living cells for the short time bioremediation. The average content of soil exchangeable fraction of Cd decreases whereas the residual fraction increases with bacterial inoculation. All our results suggest Delftia sp. B9 is able to the stabilization of Cd in soil and reduce Cd accumulation in rice grain, therefore, this strain is potentially suitable for the bioremediation of Cd-contaminated paddy soils.
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Subsurface processes influence oxidant availability and chemoautotrophic hydrogen metabolism in Yellowstone hot springs. GEOBIOLOGY 2018; 16:674-692. [PMID: 30035368 DOI: 10.1111/gbi.12308] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 04/15/2018] [Accepted: 06/20/2018] [Indexed: 06/08/2023]
Abstract
The geochemistry of hot springs and the availability of oxidants capable of supporting microbial metabolisms are influenced by subsurface processes including the separation of hydrothermal fluids into vapor and liquid phases. Here, we characterized the influence of geochemical variation and oxidant availability on the abundance, composition, and activity of hydrogen (H2 )-dependent chemoautotrophs along the outflow channels of two-paired hot springs in Yellowstone National Park. The hydrothermal fluid at Roadside East (RSE; 82.4°C, pH 3.0) is acidic due to vapor-phase input while the fluid at Roadside West (RSW; 68.1°C, pH 7.0) is circumneutral due to liquid-phase input. Most chemotrophic communities exhibited net rates of H2 oxidation, consistent with H2 support of primary productivity, with one chemotrophic community exhibiting a net rate of H2 production. Abundant H2 -oxidizing chemoautotrophs were supported by reduction in oxygen, elemental sulfur, sulfate, and nitrate in RSW and oxygen and ferric iron in RSE; O2 utilizing hydrogenotrophs increased in abundance down both outflow channels. Sequencing of 16S rRNA transcripts or genes from native sediments and dilution series incubations, respectively, suggests that members of the archaeal orders Sulfolobales, Desulfurococcales, and Thermoproteales are likely responsible for H2 oxidation in RSE, whereas members of the bacterial order Thermoflexales and the archaeal order Thermoproteales are likely responsible for H2 oxidation in RSW. These observations suggest that subsurface processes strongly influence spring chemistry and oxidant availability, which in turn select for unique assemblages of H2 oxidizing microorganisms. Therefore, these data point to the role of oxidant availability in shaping the ecology and evolution of hydrogenotrophic organisms.
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Bioaerosols concentrations in working areas in biomethanization facilities. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2017; 67:1258-1271. [PMID: 28718709 DOI: 10.1080/10962247.2017.1356762] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 06/13/2017] [Indexed: 06/07/2023]
Abstract
UNLABELLED This study sought to fill the gap in information about the type and the concentration of bioaerosols present in the air of biomethanization facilities (BF). Evaluation of bioaerosol composition and concentration was achieved in two biomethanization facilities located in Eastern Canada, during summer and winter. In order to have a thorough understanding of the studied environment, the methodology combined culture of bacteria and molds, qualitiative polymerase chain reaction (qPCR) for specific microorganisms, endotoxin quantification, and next-generation sequencing (NGS) for bacterial diversity. Results revealed that workers in biomethanization facilities are exposed to bioaerosols and pathogenic microorganisms similar to those found in composting plants. However, human exposure levels to bioaerosols are lower in BF than in composting plants. Despite these differences, use of personal protective equipment is recommended to lower the risks of health problems. IMPLICATIONS Biomethanization is a new technology used in eastern Canada for waste management. In the next few years, it is expected that there will be an expansion of facilities in response of tight governmental regulations. Workers in biomethanization facilities are exposed to various amounts of bioaerosols composed of some harmful microorganisms. Therefore, monitoring this occupational exposure could be an interesting tool for improving worker's health.
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Ramlibacter rhizophilus sp. nov., isolated from rhizosphere soil of national flower Mugunghwa from South Korea. Int J Syst Evol Microbiol 2017; 67:3773-3777. [PMID: 28879839 DOI: 10.1099/ijsem.0.002191] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A Gram-negative, aerobic, non-motile, long rods or coccoid without flagellum strain, designated THG-YS3.2.7T, was isolated from therhizosphere soil of a Mugunghwa flower collected from Kyung Hee University, Yongin, South Korea. Growth occurred at 10-40 °C (optimum 28-37 °C), at pH 6-8 (optimum 7) and at 0-5 % NaCl (optimum 1 %). The predominant ubiquinone was ubiquinone 8 (Q-8). The major cellular fatty acids were C10 : 0, C10 : 0 3OH, C16 : 0, C17 : 0, C17 : 0 cyclo, C18 : 0, C18 : 3ω6c (6,9,12), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and summed feature 8 (C18 : 1 ω7c and/or C18 : 1ω6c). The major polar lipids were diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), phosphatidylethanolamine (PE), phosphatidylcholine (PC). The DNA G+C content of strain THG-YS3.2.7T was 69.4 mol%. Based on 16S rRNA gene sequence analysis, the nearest phylogenetic neighbours of strain THG-YS3.2.7T were identified as Ramlibacter henchirensis DSM 14656T (97.92 %), Ramlibacter tataouinensis DSM 14655T (97.90 %), Ramlibacter solisilvae KACC 17567T (97.04 %). DNA-DNA hybridization values between strain THG-YS3.2.7T and R. henchirensis DSM 14656T, R. tataouinensis DSM 14655T, R. solisilvae KACC 17567T were 32.5±1.5, 43.1±1.1, 42.8±1.1 %, respectively. On the basis of the phylogenetic analysis, chemotaxonomic data, physiological characteristics and DNA-DNA hybridization data, strain THG-YS3.2.7T represent a novel species of the genus Ramlibacter, for which the name Ramlibacter rhizophilus sp. nov. is proposed. The type strain is THG-YS3.2.7T (=KCTC 52083T=CCTCC AB 2015357T).
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Anti-quorum Sensing and Anti-biofilm Activity of Delftia tsuruhatensis Extract by Attenuating the Quorum Sensing-Controlled Virulence Factor Production in Pseudomonas aeruginosa. Front Cell Infect Microbiol 2017; 7:337. [PMID: 28798903 PMCID: PMC5526841 DOI: 10.3389/fcimb.2017.00337] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 07/10/2017] [Indexed: 11/13/2022] Open
Abstract
Multidrug-resistance bacteria commonly use cell-to-cell communication that leads to biofilm formation as one of the mechanisms for developing resistance. Quorum sensing inhibition (QSI) is an effective approach for the prevention of biofilm formation. A Gram-negative bacterium, Delftia tsuruhatensis SJ01, was isolated from the rhizosphere of a species of sedge (Cyperus laevigatus) grown along the coastal-saline area. The isolate SJ01 culture and bacterial crude extract showed QSI activity in the biosensor plate containing the reference strain Chromobacterium violaceum CV026. A decrease in the violacein production of approximately 98% was detected with the reference strain C. violaceum CV026. The bacterial extract (strain SJ01) exhibited anti-quorum sensing activity and inhibited the biofilm formation of clinical isolates wild-type Pseudomonas aeruginosa PAO1 and P. aeruginosa PAH. A non-toxic effect of the bacterial extract (SJ01) was detected on the cell growth of the reference strains as P. aeruginosa viable cells were present within the biofilm. It is hypothesized that the extract (SJ01) may change the topography of the biofilm and thus prevent bacterial adherence on the biofilm surface. The extract also inhibits the motility, virulence factors (pyocyanin and rhamnolipid) and activity (elastase and protease) in P. aeruginosa treated with SJ01 extract. The potential active compound present was identified as 1,2-benzenedicarboxylic acid, diisooctyl ester. Microarray and transcript expression analysis unveiled differential expression of quorum sensing regulatory genes. The key regulatory genes, LasI, LasR, RhlI, and RhlR were down-regulated in the P. aeruginosa analyzed by quantitative RT-PCR. A hypothetical model was generated of the transcriptional regulatory mechanism inferred in P. aeruginosa for quorum sensing, which will provide useful insight to develop preventive strategies against the biofilm formation. The potential active compound identified, 1,2-benzenedicarboxylic acid, diisooctyl ester, has the potential to be used as an anti-pathogenic drug for the treatment of biofilm-forming pathogenic bacteria. For that, a detailed study is needed to investigate the possible applications.
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Abstract
A bacterial strain, designated RA6T, was isolated from the rhizosphere of Cistus ladanifer. Phylogenetic analyses based on 16S rRNA gene sequence placed the isolate into the genus Delftia within a cluster encompassing the type strains of Delftia lacustris, Delftia tsuruhatensis, Delftia acidovorans and Delftia litopenaei, which presented greater than 97 % sequence similarity with respect to strain RA6T. DNA-DNA hybridization studies showed average relatedness ranging from of 11 to 18 % between these species of the genus Delftia and strain RA6T. Catalase and oxidase were positive. Casein was hydrolysed but gelatin and starch were not. Ubiquinone 8 was the major respiratory quinone detected in strain RA6T together with low amounts of ubiquinones 7 and 9. The major fatty acids were those from summed feature 3 (C16 : 1ω7c/C16 : 1 ω6c) and C16 : 0. The predominant polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. Phylogenetic, chemotaxonomic and phenotypic analyses showed that strain RA6T should be considered as a representative of a novel species of genus Delftia, for which the name Delftia rhizosphaerae sp. nov. is proposed. The type strain is RA6T (=LMG 29737T= CECT 9171T).
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Corynebacterium defluvii sp. nov., isolated from Sewage. J Microbiol 2017; 55:435-439. [PMID: 28429167 DOI: 10.1007/s12275-017-6592-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 02/09/2017] [Accepted: 02/13/2017] [Indexed: 11/29/2022]
Abstract
A Gram-positive, aerobic, non-motile, rod-shapeds, catalase-positive, and oxidase-negative strain, designated Y49T, was isolated from sewage collected from Jilin Agricultural University, China. It grew at 20-40°C (optimum at 30°C), at pH 6.0-8.0 (optimum at 7.0) and at 0-1.0% sodium chloride (optimum at 0%). The major isoprenoid quinone was menaquinone-8 (MK-8) and the polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylmethylethanolamine, four unidentified lipids, and two unidentified aminolipids. The peptidoglycan was meso-diaminopimelic acid. The cell-wall sugars were galactose, arabinose, and glucose. The fatty acids were C9:0, C16:0, C16:1 ω9c, C17:1 ω9c, C18:3 ω6c (6,9,12), C18:1 ω9c, and C18:0. The DNA G+C content was 51.4 mol%. Based on the 16S rRNA gene sequence analysis, the nearest phylogenetic neighbors of strain Y49T were Corynebacterium efficiens DSM 44549T (97.5%), Corynebacterium callunae DSM 20147T (97.2%), Corynebacterium deserti GIMN 1.010T (96.8%), Corynebacterium glutamicum ATCC 13032T (96.4%), and other species belonging to this genus (92.3-95.4%). The DNA-DNA relatedness value between strain Y49T and C. efficiens DSM 44549T, C. callunae DSM 20147T, C. deserti GIMN1.010T, and C. glutamicum ATCC 13032T was 25.5±2.0%, 21.1±1.0%, 16.5±0.5%, and 13.5±0.9%, respectively. Based on the phylogenetic analysis, chemotaxonomic data, physiological characteristics and DNA-DNA hybridization data, strain Y49T represents a novel species of the genus Corynebacterium, for which the name Corynebacterium defluvii sp nov. is proposed. The type strain is Y49T (= KCTC 39731T =CGMCC 1.15506T).
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Niastella hibisci sp. nov., isolated from rhizosphere soil of mugunghwa, the Korean national flower. Int J Syst Evol Microbiol 2016; 66:5218-5222. [DOI: 10.1099/ijsem.0.001498] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Lysobacter rhizophilus sp. nov., isolated from rhizosphere soil of mugunghwa, the national flower of South Korea. Int J Syst Evol Microbiol 2016; 66:4754-4759. [DOI: 10.1099/ijsem.0.001422] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Community Analysis and Recovery of Phenol-degrading Bacteria from Drinking Water Biofilters. Front Microbiol 2016; 7:495. [PMID: 27148185 PMCID: PMC4828441 DOI: 10.3389/fmicb.2016.00495] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 03/27/2016] [Indexed: 11/13/2022] Open
Abstract
Phenol is a ubiquitous organic contaminant in drinking water. Biodegradation plays an important role in the elimination of phenol pollution in the environment, but the information about phenol removal by drinking water biofilters is still lacking. Herein, we study an acclimated bacterial community that can degrade over 80% of 300 mg/L phenol within 3 days. PCR detection of genotypes involved in bacterial phenol degradation revealed that the degradation pathways contained the initial oxidative attack by phenol hydroxylase, and subsequent ring fission by catechol 1,2-dioxygenase. Based on the PCR denatured gradient gel electrophoresis (PCR-DGGE) profiles of bacteria from biological activated carbon (BAC), the predominant bacteria in drinking water biofilters including Delftia sp., Achromobacter sp., and Agrobacterium sp., which together comprised up to 50% of the total microorganisms. In addition, a shift in bacterial community structure was observed during phenol biodegradation. Furthermore, the most effective phenol-degrading strain DW-1 that correspond to the main band in denaturing gradient gel electrophoresis (DGGE) profile was isolated and identified as Acinetobacter sp., according to phylogenetic analyses of the 16S ribosomal ribonucleic acid (rRNA) gene sequences. The strain DW-1 also produced the most important enzyme, phenol hydroxylase, and it also exhibited a good ability to degrade phenol when immobilized on granular active carbon (GAC). This study indicates that the enrichment culture has great potential application for treatment of phenol-polluted drinking water sources, and the indigenous phenol-degrading microorganism could recover from drinking water biofilters as an efficient resource for phenol removal. Therefore, the aim of this study is to draw attention to recover native phenol-degrading bacteria from drinking water biofilters, and use these native microorganisms as phenolic water remediation in drinking water sources.
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Aeromicrobium halotolerans sp. nov., isolated from desert soil sample. Arch Microbiol 2016; 198:423-7. [DOI: 10.1007/s00203-016-1196-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2015] [Revised: 01/24/2016] [Accepted: 01/27/2016] [Indexed: 10/22/2022]
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Control of Wilt and Rot Pathogens of Tomato by Antagonistic Pink Pigmented Facultative Methylotrophic Delftia lacustris and Bacillus spp. FRONTIERS IN PLANT SCIENCE 2016; 7:1626. [PMID: 27872630 PMCID: PMC5097904 DOI: 10.3389/fpls.2016.01626] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 10/14/2016] [Indexed: 05/13/2023]
Abstract
The studies on the biocontrol potential of pink pigmented facultative methylotrophic (PPFM) bacteria other than the genus Methylobacterium are scarce. In the present study, we report three facultative methylotrophic isolates; PPO-1, PPT-1, and PPB-1, respectively, identified as Delftia lacustris, Bacillus subtilis, and Bacillus cereus by 16S rRNA gene sequence analysis. Hemolytic activity was tested to investigate the potential pathogenicity of isolates to plants and humans, the results indicates that the isolates PPO-1, PPT-1, and PPB-1 are not pathogenic strains. Under in vitro conditions, D. lacustris PPO-1, B. subtilis PPT-1, and B. cereus PPB-1 showed direct antagonistic effect by inhibiting the mycelial growth of fungal pathogens; Fusarium oxysporum f. sp. lycopersici (2.15, 2.05, and 1.95 cm), Sclerotium rolfsii (2.14, 2.04, and 1.94 cm), Pythium ultimum (2.12, 2.02, and 1.92 cm), and Rhizoctonia solani (2.18, 2.08, and 1.98 cm) and also produced volatile inhibitory compounds. Under plant growth chamber condition methylotrophic bacterial isolates; D. lacustris PPO-1, B. subtilis PPT-1, and B. cereus PPB-1 significantly reduced the disease incidence of tomato. Under greenhouse condition, D. lacustris PPO-1, B. subtilis PPT-1, and B. cereus PPB-1 inoculated tomato plants, when challenged with F. oxysporum f. sp. lycopersici, S. rolfsii, P. ultimum, and R. solani, increased the pathogenesis related proteins (β-1,3-glucanase and chitinase) and defense enzymes (phenylalanine ammonia lyase, peroxidase, polyphenol oxidase, and catalase) on day 5 after inoculation. In the current study, we first report the facultative methylotrophy in pink pigmented D. lacustris, B. subtilis, and B. cereus and their antagonistic potential against fungal pathogens. Direct antagonistic and ISR effects of these isolates against fungal pathogens of tomato evidenced their possible use as a biocontrol agent.
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Discovery of keratinases using bacteria isolated from marine environments. Syst Appl Microbiol 2015; 39:49-57. [PMID: 26607323 DOI: 10.1016/j.syapm.2015.10.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Revised: 10/23/2015] [Accepted: 10/27/2015] [Indexed: 11/30/2022]
Abstract
Bacteria are important for the biodegradation of keratin. Thus, a workflow to isolate keratin-degrading bacteria utilizing an optimized azo-keratin assay was established. Deteriorated feather samples, collected in marine shoreline environments from the intertidal zone, yielded 50 unique bacterial isolates exhibiting keratin degradation when feather meal was supplied as keratin substrate. The majority of isolates, identified by 16S sequencing, belonged to genera previously reported to produce keratinases: Bacillus spp. (42%) and Stenotrophomonas spp. (40%). The remaining 18% represented the genera Alcaligenes, Chryseobacterium, Salinivibrio, Delftia, Stappia, and Microbacterium, genera not previously been associated with keratinase production. The workflow, also applied to 21 Bacilli from our in-house culture collection, additionally revealed four Bacilli with remarkable feather degradation potential. The industrial applicability of their associated keratinases was evaluated and the most active keratinase expressed in E. coli to confirm keratinase expression. Enriched keratinase fractions demonstrated activity up to 75°C and retained viability when stored lyophilized at 20°C for up to 200d.
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Ocular infection associated with Delftia lacustris: first report. Braz J Infect Dis 2015; 19:449-50. [PMID: 26095905 PMCID: PMC9427517 DOI: 10.1016/j.bjid.2015.05.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2015] [Accepted: 05/06/2015] [Indexed: 11/24/2022] Open
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Bacteriophage therapy for membrane biofouling in membrane bioreactors and antibiotic-resistant bacterial biofilms. Biotechnol Bioeng 2015; 112:1644-54. [PMID: 25728819 DOI: 10.1002/bit.25574] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Revised: 01/06/2015] [Accepted: 02/13/2015] [Indexed: 11/06/2022]
Abstract
To demonstrate elimination of bacterial biofilm on membranes to represent wastewater treatment as well as biofilm formed by antibiotic-resistant bacterial (ARB) to signify medical application, an antibiotic-resistant bacterium and its lytic bacteriophage were isolated from a full-scale wastewater treatment plant. Based on gram staining and complete 16 S rDNA sequencing, the isolated bacterium showed a more than 99% homology with Delftia tsuruhatensis, a gram-negative bacterium belonging to β-proteobacteria. The Delftia lytic phage's draft genome revealed the phage to be an N4-like phage with 59.7% G + C content. No transfer RNAs were detected for the phage suggesting that the phage is highly adapted to its host Delftia tsuruhatensis ARB-1 with regard to codon usage, and does not require additional tRNAs of its own. The gene annotation of the Delftia lytic phage found three different components of RNA polymerase (RNAP) in the genome, which is a typical characteristic of N4-like phages. The lytic phage specific to D. tsuruhatensis ARB-1 could successfully remove the biofilm formed by it on a glass slide. The water flux through the membrane of a prototype lab-scale membrane bioreactor decreased from 47 L/h m(2) to ∼15 L/h m(2) over 4 days due to a biofilm formed by D. tsuruhatensis ARB-1. However, the flux increased to 70% of the original after the lytic phage application. Overall, this research demonstrated phage therapy's great potential to solve the problem of membrane biofouling, as well as the problems posed by pathogenic biofilms in external wounds and on medical instruments.
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Characterization and Genomic Analysis of Quinolone-Resistant Delftia sp. 670 Isolated from a Patient Who Died from Severe Pneumonia. Curr Microbiol 2015; 71:54-61. [PMID: 25935202 DOI: 10.1007/s00284-015-0818-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 03/04/2015] [Indexed: 11/29/2022]
Abstract
Antibiotic-resistant opportunistic pathogens have become a serious concern in recent decades, as they are increasingly responsible for hospital-acquired infections. Here, we describe quinolone-resistant Delftia sp. strain 670, isolated from the sputum of a patient who died from severe pulmonary infection. The draft genome sequence of this strain was obtained by whole-genome shotgun sequencing, and was subjected to comparative genome analysis. Genome analysis revealed that one critical mutation (Ser83Ile in gyrA) might play a decisive role in quinolone resistance. The genome of Delftia sp. strain 670 contains both type II and type VI secretion systems, which were predicted to contribute to the virulence of the strain. Phylogenetic analysis, assimilation tests, and comparative genome analysis indicated that strain 670 differed from the four known Delftia species, suggesting this strain could represent a novel species. Although the study could not determine the strain 670 as the pathogen led to mortality, our findings also presented the pathogenic potential of Delftia species, and the increasing severity of antibiotic resistance among emerging opportunistic pathogens. The whole genome sequencing and comparative analysis improved our understanding of genome evolution in the genus Delftia, and provides the foundation for further study on drug resistance and virulence of Delftia strains.
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Marivirga atlantica sp. nov., isolated from seawater and emended description of the genus
Marivirga. Int J Syst Evol Microbiol 2015; 65:1515-1519. [DOI: 10.1099/ijs.0.000126] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A novel Gram-stain-negative, aerobic, orange-pigmented, non-flagellated, gliding, rod-shaped bacterium, designated strain SM1354T was isolated from surface seawater of the Atlantic Ocean. The strain hydrolysed gelatin and DNA but did not reduce nitrate. It grew at 4–40 °C and with 0.5–11 % (w/v) NaCl. Phylogenetic analysis of the 16S rRNA gene sequences revealed that strain SM1354T belonged to the genus
Marivirga
with 96.0–96.2 % sequence similarities to known species of the genus
Marivirga
. The major fatty acids of strain SM1354T were iso-C15 : 0, iso-C15 : 1 G, iso-C17 : 03-OH and summed feature 3 (C16 : 1ω7c and/or iso-C15 : 02-OH). Polar lipids of strain SM1354T included phosphatidylethanolamine, three unidentified lipids and one unidentified aminolipid and aminophospholipid. The major respiratory quinone of strain SM1354T was menaquinone 7 (MK-7). The genomic DNA G+C content of strain SM1354T was 33.9±0.4 mol%. On the basis of the results of the polyphasic characterization in this study, it is proposed that strain SM1354T represents a novel species of the genus
Marivirga
, namely Marivirga atlantica sp. nov. The type strain of Marivirga atlantica is SM1354T ( = CCTCC AB 2014242T = JCM 30305T). An emended description of the genus
Marivirga
is also proposed.
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Delftia deserti sp. nov., isolated from a desert soil sample. Antonie van Leeuwenhoek 2015; 107:1445-50. [DOI: 10.1007/s10482-015-0440-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Accepted: 03/26/2015] [Indexed: 10/23/2022]
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Abstract
We report the first case of true Delftia lacustris bacteremia in a patient with pheochromocytoma. The organism was identified using 16S rRNA gene sequencing and biochemical tests. A peripheral intravenous catheter was the suspected source of infection, and the patient was successfully treated with piperacillin/tazobactam. We also present a review of the literature describing bacteremia caused by Delftia species.
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Bioinformatic evaluation of the secondary metabolism of antistaphylococcal environmental bacterial isolates. Can J Microbiol 2013; 59:465-71. [DOI: 10.1139/cjm-2013-0016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The increasing occurrence of drug-resistant Staphylococcus aureus is exacerbated with a declining rate of antibiotic discovery, particularly those with new mechanisms of action. The decline in antibiotic discovery from traditional sources, such as soil actinobacteria, necessitates examination of lesser studied microbes. Here, we present a strategy to select for organisms that may have a propensity to result in new antistaphylococcal agents by using S. aureus as a bait organism, and selecting organisms that have a natural lytic activity towards it. We have isolated over 80 environmental isolates and typed these organisms using 16S rDNA sequence comparison and deployed bioinformatics to assess the secondary metabolic potential of the isolated antistaphylococcal bacteria using genomic sequences. Bioinformatic analysis highlights the enriched and unique suite of potential antibiotic polyketides and nonribosomal peptides and lantibiotic gene clusters from these organisms. Profiling organic microbial extracts further showed that many of the organisms from the 10 staphylolytic genera secrete agents with antistaphylococcal activity and may serve as new sources for future antistaphylococcal drug discovery.
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Grazing resistant freshwater bacteria profit from chitin and cell-wall-derived organic carbon. Environ Microbiol 2013; 15:2019-30. [PMID: 23413977 DOI: 10.1111/1462-2920.12083] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Revised: 12/12/2012] [Accepted: 01/03/2013] [Indexed: 11/27/2022]
Abstract
The rise of grazing resistant planktonic bacteria in freshwater lakes during vernal phytoplankton blooms is favoured by predation of heterotrophic nanoflagellates (HNF). The spring period is also characterized by increased availability of organic carbon species that are in parts derived from cellular debris generated during bacterivory or viral lysis, such as peptidoglycan, chitin and their subunit N-acetylglucosamine (NAG). We tested the hypothesis that two dominant grazing resistant bacterial taxa, the ac1 tribe of Actinobacteria (ac1) and filamentous bacteria from the LD2 lineage (Saprospiraceae), profit from such carbon sources during periods of intense HNF predation. The abundances of ac1 and LD2 rose in parallel with HNF, and disproportionally high fractions of cells from both lineages were involved in NAG uptake. Members of ac1 and LD2 were significantly more enriched after NAG addition to lake water. However, highest growth rates of both bacterial lineages were found on chitin and peptidoglycan. Moreover, the direct or indirect transfer of organic carbon from peptidoglycan to LD2 filaments could be demonstrated. We thus provide evidence that these taxa may benefit twofold from protistan predation: by removal of their competitors, and by specific physiological adaptations to utilize carbon sources that are released during grazing or viral lysis.
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Microbial diversity in a continuous system based on rice husks for biodegradation of the azo dyes Reactive Red 2 and Reactive Black 5. BIORESOURCE TECHNOLOGY 2013; 130:681-688. [PMID: 23334027 DOI: 10.1016/j.biortech.2012.12.097] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Revised: 12/11/2012] [Accepted: 12/12/2012] [Indexed: 06/01/2023]
Abstract
In the present study the degradation of two common azo dyes used in dye houses today, Reactive Black 5 and Reactive Red 2 was evaluated in biofilters. In two experiments, bioreactors performed over 80% decolorization at a hydraulic retention time of only 28.4h with little production of metabolites. Molecular analyses showed a diverse and dynamic bacterial community composition in the bioreactors, including members of the Bacteroidetes, Acinetobacter (Gammaproteobacteria) and Clostridium (Firmicutes) that possess the capacity to reduce azo dyes. Collectively, the results indicate that the development of mixed bacterial communities from natural biomaterials contributes to an efficient and robust degradation performance in bioreactors even at high concentration of dyes.
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Delftia litopenaei sp. nov., a poly-β-hydroxybutyrate-accumulating bacterium isolated from a freshwater shrimp culture pond. Int J Syst Evol Microbiol 2012; 62:2315-2321. [DOI: 10.1099/ijs.0.037507-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A Gram-negative, short-rod-shaped, motile, non-spore-forming and poly-β-hydroxybutyrate-accumulating bacterial strain, designated wsw-7T, was isolated from a freshwater shrimp culture pond in Taiwan and was characterized using a polyphasic taxonomic approach. Phylogenetic analyses based on 16S rRNA gene sequences showed that the closest relatives of strain wsw-7T were
Delftia lacustris
332T,
Delftia tsuruhatensis
T7T and
Delftia acidovorans
ATCC 15668T, with sequence similarities of 98.5, 98.4 and 97.9 %, respectively. Phylogenetic trees obtained with 16S rRNA gene sequences or the polyhydroxyalkanoate synthase (phaC) gene sequences revealed that strain wsw-7T and these three closest relatives formed an independent phylogenetic clade within the order
Burkholderiales
. Strain wsw-7T contained summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0 and C18 : 1ω7c as predominant fatty acids. The major isoprenoid quinone was Q-8 and the DNA G+C content was 67.6 mol%. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, an uncharacterized aminolipid and several uncharacterized phospholipids. On the basis of the genotypic, chemotaxonomic and phenotypic data, strain wsw-7T represents a novel species in the genus
Delftia
, for which the name Delftia litopenaei sp. nov. is proposed; the type strain is wsw-7T ( = BCRC 80212T = LMG 25724T).
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Four cases of possible human infections with Delftia lacustris. Infection 2012; 40:709-12. [PMID: 23055149 DOI: 10.1007/s15010-012-0339-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Accepted: 09/12/2012] [Indexed: 12/01/2022]
Abstract
We report four cases of possible human infections with Delftia lacustris. D. lacustris isolates, which were isolated from blood cultures and bile fluid of patients with underlying diseases such as empyema, renal injury, hepatocellular carcinoma, and renal infarction, were identified using 16S rRNA gene sequencing and biochemical tests. Four D. lacustris isolates did not show the same antimicrobial susceptibility profiles and enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) patterns, indicating their non-clonality.
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Diversity of the heterotrophic microbial populations for distinguishing natural mineral waters. Int J Food Microbiol 2012; 153:38-44. [DOI: 10.1016/j.ijfoodmicro.2011.10.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2011] [Revised: 07/28/2011] [Accepted: 10/23/2011] [Indexed: 11/19/2022]
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Detection, cellular localization and antibacterial activity of two lytic enzymes of Pediococcus acidilactici ATCC 8042. J Appl Microbiol 2011; 111:607-15. [DOI: 10.1111/j.1365-2672.2011.05088.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Beta-1,3-glucanase from Delftia tsuruhatensis strain MV01 and its potential application in vinification. Appl Environ Microbiol 2010; 77:983-90. [PMID: 21169426 DOI: 10.1128/aem.01943-10] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
During vinification microbial activities can spoil wine quality. As the wine-related lactic acid bacterium Pediococcus parvulus is able to produce slimes consisting of a β-1,3-glucan, must and wine filtration can be difficult or impossible. In addition, the metabolic activities of several wild-type yeasts can also negatively affect wine quality. Therefore, there is a need for measures to degrade the exopolysaccharide from Pediococcus parvulus and to inhibit the growth of certain yeasts. We examined an extracellular β-1,3-glucanase from Delftia tsuruhatensis strain MV01 with regard to its ability to hydrolyze both polymers, the β-1,3-glucan from Pediococcus and that from yeast cell walls. The 29-kDa glycolytic enzyme was purified to homogeneity. It exhibited an optimal activity at 50°C and pH 4.0. The sequencing of the N terminus revealed significant similarities to β-1,3-glucanases from different bacteria. In addition, the investigations indicated that this hydrolytic enzyme is still active under wine-relevant parameters such as elevated ethanol, sulfite, and phenol concentrations as well as at low pH values. Therefore, the characterized enzyme seems to be a useful tool to prevent slime production and undesirable yeast growth during vinification.
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Human infection with Delftia tsuruhatensis isolated from a central venous catheter. J Med Microbiol 2010; 60:246-248. [PMID: 20965913 DOI: 10.1099/jmm.0.021238-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We present the case of a patient with catheter-related infection caused by Delftia tsuruhatensis, a newly described species closely related to Delftia acidovorans (formerly Comamonas acidovorans). To date, D. tsuruhatensis has not been described as a pathogen. To the best of our knowledge, this is the first report describing D. tsuruhatensis as the causative agent of a human infection.
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Vogesella mureinivorans sp. nov., a peptidoglycan-degrading bacterium from lake water. Int J Syst Evol Microbiol 2009; 60:2467-2472. [PMID: 19946047 DOI: 10.1099/ijs.0.018630-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A novel, non-pigmented, rod-shaped, Gram-negative strain was isolated from mesotrophic lake water in Zealand, Denmark. Phylogenetic analysis of the 16S rRNA gene sequence of the bacterium, designated strain 389(T), indicated that the strain belonged to the genus Vogesella and formed a monophyletic group with Vogesella perlucida DS-28(T) (99.1 % nucleotide similarity); it was less related to Vogesella indigofera ATCC 19706(T) (96.9 % similarity) and Vogesella lacus LMG 24504(T) (96.8 % similarity). Hybridization of DNA from strain 389(T) and V. perlucida demonstrated a reassociation of 50.6 ± 9.6 %. The DNA G+C content of strain 389(T) was 61.2 mol%. The fatty acid profile of the strain differed from those of the other strains representing the genus Vogesella by a high content of C₁₆:₁ω7c and/or iso-C₁₅:₀ 2-OH (71.6 %) and a lower content of C₁₆: ₀. Strain 389(T) was capable of degrading peptidoglycan and had chitinase and lysozyme activities, possibly associated with the degradation of peptidoglycan, and had capacity for degradation of several other polymer compounds. Based on phenotypic and genotypic characteristics, strain 389(T) represents a novel species, for which we propose the name Vogesella mureinivorans sp. nov. The type strain is 389(T) (=DSM 21247(T) =LMG 25302(T)).
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