| 1. |
- Alcamán, M. Estrella, et al.
(författare)
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Physiological and gene expression responses to nitrogen regimes and temperatures in Mastigocladus sp strain CHP1, a predominant thermotolerant cyanobacterium of hot springs
- 2017
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Ingår i: Systematic and Applied Microbiology. - : Elsevier BV. - 0723-2020 .- 1618-0984. ; 40:2, s. 102-113
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Tidskriftsartikel (refereegranskat)abstract
- Cyanobacteria are widely distributed primary producers with significant implications for the global biogeochemical cycles of carbon and nitrogen. Diazotrophic cyanobacteria of subsection V (Order Stigonematales) are particularly ubiquitous in photoautotrophic microbial mats of hot springs. The Stigonematal cyanobacterium strain CHPI isolated from the Porcelana hot spring (Chile) was one of the major contributors of the new nitrogen through nitrogen fixation. Further morphological and genetic characterization verified that the strain CHP1 belongs to Stigonematales, and it formed a separate Glade together with other thermophiles of the genera Fischerella and Mastigocladus. Strain CHP1 fixed maximum N-2 in the light, independent of the temperature range. At 50 degrees C niJH gene transcripts showed high expression during the light period, whereas the nifH gene expression at 45 degrees C was arrhythmic. The strain displayed a high affinity for nitrate and a low tolerance for high ammonium concentrations, whereas the narB and glnA genes showed higher expression in light and at the beginning of the dark phase. It is proposed that Mastigocladus sp. strain CHPI would represent a good model for the study of subsection V thermophilic cyanobacteria, and for understanding the adaptations of these photoautotrophic organisms inhabiting microbial mats in hot springs globally.
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| 2. |
- Ampomah, Osei Yaw, et al.
(författare)
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Diverse Mesorhizobium bacteria nodulate native Astragalus and Oxytropis in arctic and subarctic areas in Eurasia
- 2017
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Ingår i: Systematic and Applied Microbiology. - : Elsevier. - 0723-2020 .- 1618-0984. ; 40:1, s. 51-58
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Tidskriftsartikel (refereegranskat)abstract
- Rhizobia nodulating native Astragalus and Oxytropis spp. in Northern Europe are not well-studied. In this study, we isolated bacteria from nodules of four Astragalus spp. and two Oxytropis spp. from the arctic and subarctic regions of Sweden and Russia. The phylogenetic analyses were performed by using sequences of three housekeeping genes (16S rRNA, rpoB and recA) and two accessory genes (nodC and nifH). The results of our multilocus sequence analysis (MLSA) of the three housekeeping genes tree showed that all the 13 isolates belonged to the genus Mesorhizobium and were positioned in six clades. Our concatenated housekeeping gene tree also suggested that the isolates nodulating Astragalus inopinatus, Astragalus frigidus, Astragalus alpinus ssp. alpinus and Oxytropis revoluta might be designated as four new Mesorhizobium species. The 13 isolates were grouped in three clades in the nodC and nifH trees. N-15 analysis suggested that the legumes in association with these isolates were actively fixing nitrogen. (C) 2016 Elsevier GmbH. All rights reserved.
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| 3. |
- Ampomah, Osei Yaw, et al.
(författare)
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Genetic diversity of rhizobia nodulating native Vicia spp. in Sweden
- 2016
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Ingår i: Systematic and Applied Microbiology. - : Elsevier. - 0723-2020 .- 1618-0984. ; 39:3, s. 203-210
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Tidskriftsartikel (refereegranskat)abstract
- Despite the recognition that Rhizobium leguminosarum sv. viciae is the most common symbiont of Vicia species worldwide, there is no available information on rhizobia nodulating native Vicia species in Sweden. We have therefore studied the genetic diversity and phylogeny of root nodule bacteria isolated from V. cracca, V. hirsuta, V. sepium, V. tetrasperma and V. sylvatica growing in different locations in Sweden as well as an isolate each from V. cracca in Tromso, Norway, and V. multicaulis in Siberia, Russia. Out of 25 isolates sampled from the six Vicia species in 12 different locations, there were 14 different genotypes based on the atpD, recA and nodA gene phylogenies. All isolates were classified into Rhizobium leguminosarum sv. viciae group based on the concatenated atpD and recA phylogeny and the nodA phylogeny. (C) 2016 Elsevier GmbH. All rights reserved.
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| 4. |
- Korlević, Marino, et al.
(författare)
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Bacterial diversity across a highly stratified ecosystem : A salt-wedge Mediterranean estuary
- 2016
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Ingår i: Systematic and Applied Microbiology. - : Elsevier BV. - 0723-2020 .- 1618-0984. ; 39:6, s. 398-408
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Tidskriftsartikel (refereegranskat)abstract
- Highly stratified Mediterranean estuaries are unique environments where the tidal range is low and the tidal currents are almost negligible. The main characteristics of these environments are strong salinity gradients and other environmental parameters. In this study, 454 pyrosequencing of the 16S rRNA gene in combination with catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH) was used to estimate the bacterial diversity across the Krka estuary in February and July 2013. The comparison of the data derived from these two techniques resulted in a significant but weak positive correlation (R = 0.28) indicating a substantial difference in the bacterial community structure, depending on the applied method. The phytoplankton bloom observed in February was identified as one of the main factors shaping the bacterial community structure between the two environmentally contrasting sampling months. Roseobacter, Bacteroidetes and Gammaproteobacteria differed substantially between February and July. Typical freshwater bacterial classes (Actinobacteria and Betaproteobacteria) showed strong vertical distribution patterns depending on the salinity gradient. Cyanobacteria decreased in abundance in February due to competition with phytoplankton, while the SAR11 clade increased its abundance in July as a result of a better adaptation toward more oligotrophic conditions. The results provided the first detailed insight into the bacterial diversity in a highly stratified Mediterranean karstic estuary.
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| 5. |
- Schreiber, Lars, et al.
(författare)
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Description of Endozoicomonas ascidiicola sp nov., isolated from Scandinavian ascidians
- 2016
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Ingår i: Systematic and Applied Microbiology. - : Elsevier BV. - 0723-2020 .- 1618-0984. ; 39:5, s. 313-318
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Tidskriftsartikel (refereegranskat)abstract
- Two gram-negative, facultative anaerobic, chemoorganoheterotrophic, motile and rod-shaped bacteria, strains AVMARTO5(T) and KASP37, were isolated from ascidians (Tunicata, Ascidiaceae) of the genus Ascidiella collected at Gullmarsfjord, Sweden. The strains are the first cultured representatives of an ascidian-specific lineage within the genus Endozoicomonas (Gammaproteobacteria, Oceanospirillales, Hahellaceae). Both strains feature three distinct 16S rRNA gene paralogs, with identities of 98.9-99.1% (AVMARTO5(T)) and 97.7-98.8% (KASP37) between paralogs. The strains are closely related to Endozoicomonas atrinae and Endozoicomonas elysicola, with which they share 97.3-98.0% 16S rRNA gene sequence identity. Digital DNA-DNA hybridization, average nucleotide identity, and tetra-nucleotide correlation analysis indicate that both strains belong to a single species distinct from their closest relatives. Both strains feature similar DNA G + C contents of 46.70 mol%(AVMARTO5T) and 44.64 mol%(KASP37).The fatty acid patterns of AVMARTO5(T) and KASP37 are most similar to those of Endozoicomonas euniceicola and Endozoicomonas gorgoniicola. Based on the polyphasic approach, we propose the species Endozoicomonas ascidiicola sp. nov. to accommodate the newly isolated strains. E. ascidiicola sp. nov. is represented by the type strain AVMARTO5(T) (=DSM 100913(T) = LMG 29095(T)) and strain KASP37 (=DSM 100914= LMG 29096).
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| 6. |
- Lakade, Sameer S., et al.
(författare)
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Novel capsule phase microextraction in combination with liquid chromatography-tandem mass spectrometry for determining personal care products in environmental water
- 2018
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Ingår i: Analytical and Bioanalytical Chemistry. - : Springer Berlin/Heidelberg. - 1618-2642 .- 1618-2650. ; 410:12, s. 2991-3001
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Tidskriftsartikel (refereegranskat)abstract
- A novel sample preparation technique named capsule phase microextraction (CPME) is presented here. The technique utilizes a miniaturized microextraction capsule (MEC) as the extraction medium. The MEC consists of two conjoined porous tubular polypropylene membranes, one of which encapsulates the sorbent through sol-gel technology, while the other encapsulates a magnetic metal rod. As such, MEC integrates both the extraction and stirring mechanisms into a single device. The aim of this article is to demonstrate the application potential of CPME as sample preparation technique for the extraction of a group of personal care products (PCPs) from water matrices. Among the different sol-gel sorbent materials (UCON®, poly(caprolactone-dimethylsiloxane-caprolactone) (PCAP-DMS-CAP) and Carbowax 20M (CW-20M)) evaluated, CW-20M MEC demonstrated the best extraction performance for the selected PCPs. The extraction conditions for sol-gel CW-20M MEC were optimized, including sample pH, stirring speed, addition of salt, extraction time, sample volume, liquid desorption solvent, and time. Under the optimal conditions, sol-gel CW-20M MEC provided recoveries, ranging between 47 and 90% for all analytes, except for ethylparaben, which showed a recovery of 26%. The method based on CPME with sol-gel CW-20M followed by liquid chromatography-tandem mass spectrometry was developed and validated for the extraction of PCPs from river water and effluent wastewater samples. When analyzing different environmental samples, some analytes such as 2,4-dihydroxybenzophenone, 2,2-dihydroxy-4-4 methoxybenzophenone and 3-benzophenone were found at low ng L−1.
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| 7. |
- Eevers, N, et al.
(författare)
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Comparison between cultivated and total bacterial communities associated with Cucurbita pepo using cultivation-dependent techniques and 454 pyrosequencing.
- 2015
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Ingår i: Systematic and Applied Microbiology. - : Elsevier BV. - 0723-2020.
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Tidskriftsartikel (refereegranskat)abstract
- Endophytic bacteria often have beneficial effects on their host plants that can be exploited for bioremediation applications but, according to the literature, only 0.001-1% of all endophytic microbes should be cultivable. This study compared the cultivated endophytic communities of the roots and shoots of Cucurbita pepo with the total endophytic communities as determined by cultivation-dependent techniques and 454 pyrosequencing. The ten most abundant taxa of the total communities aligned well with the cultivated taxa; however, the abundance of these taxa in the two communities differed greatly. Enterobacter showed very low presence in the total communities, whereas they were dominantly present in the cultivated communities. Although Rhizobium dominated in total root and shoot communities, it was poorly cultivable and even then only in growth media containing plant extract. Since endophytes likely contribute to plant-growth promotion, cultivated bacterial strains were tested for their plant-growth promoting capabilities, and the results were correlated with their abundance in the total community. Bacillus and Pseudomonas showed promising results when considering cultivability, abundance in the total community and plant-growth promoting capability. This study demonstrated that, although a limited number of bacterial genera were cultivable, current cultivation-dependent techniques may be sufficient for further isolation and inoculation experiments that aim to improve phytoremediation efficiency.
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| 8. |
- Glaeser, S. P., et al.
(författare)
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Varibaculum anthropi sp nov represented by three genetically different genomovars isolated from clinical material and emended description of the genus Varibaculum
- 2016
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Ingår i: Systematic and Applied Microbiology. - : Elsevier BV. - 0723-2020. ; 39:8, s. 546-552
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Tidskriftsartikel (refereegranskat)abstract
- During the years 1994-2011 five strictly anaerobic, Gram-stain-positive, diphtheroid bacteria (strains CCUG 31793(T), CCUG 44221, CCUG 61255, CCUG 45114, and CCUG 44993) were isolated from different clinical samples in Sweden and the United Kingdom. Comparative analysis of 16S rRNA gene sequences showed that the five strains shared 99-100% 16S rRNA gene sequence similarity among each other and 98.3-98.6% sequence similarity to Varibaculum cambriense DSM 15806(T). Genomic fingerprint patterns generated with ERIC-, BOX-, and RAPD-PCR, and whole genome sequence (WGS) based comparison by in silico DNA-DNA hybridization (isDDH), average nucleotide identity (ANI) analysis and six housekeeping gene (atpA, rpoB, pgi, metG, gltA and gyrA) based multilocus sequence analysis (MLSA) showed that the strains could be differentiated from V. cambrienSe DSM 15806(T) and formed three genomic groups, which could only be differentiated at the species border level. Based on physiological characterizations the five strains could not be clearly distinguished among each other. Based on those data a new Varibaculum species, Varibaculum anthropi (type strain CCUG 31793(T)-JCM 19104(T)) is proposed including three genetically distinct genomovars (gv 1: CCUG 31793(T), CCUG 44221, CCUG 61255; gv 2: CCUG 45114, and gv 3: CCUG 44993). (C) 2016 Elsevier GmbH. All rights reserved.
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| 9. |
- Karlsson, R., et al.
(författare)
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Proteotyping: Proteomic characterization, classification and identification of microorganisms - A prospectus
- 2015
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Ingår i: Systematic and Applied Microbiology. - : Elsevier BV. - 0723-2020. ; 38:4, s. 246-257
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Forskningsöversikt (refereegranskat)abstract
- Modern microbial systematics requires a range of methodologies for the comprehensive characterization, classification and identification of microorganisms. While whole-genome sequences provide the ultimate reference for defining microbial phylogeny and taxonomy, selected biomarker-based strategies continue to provide the means for the bulk of microbial systematic studies. Proteomics, the study of the expression of genes, as well as the structure and function of the resulting proteins, offers indirect measures of genome sequence data. Recent developments in applications of proteomics for analyzing microorganisms have paralleled the growing microbial genome sequence database, as well as the evolution of mass spectrometry (MS) instrumentation and bioinformatics. MALDI-TOF MS, which generates proteomic mass patterns for 'fingerprint'-based characterizations, has provided a marked breakthrough for microbial identification. However, MALDI-TOF MS is limited in the number of targets that can be detected for strain characterization. Advanced methods of tandem mass spectrometry, in which proteins and peptides generated from proteins, are characterized and identified, using LC-MS/MS, provide the ability to detect hundreds or thousands of expressed microbial strain markers for high-resolution characterizations and identifications. Model studies demonstrate the application of proteomics-based analyses for bacterial species- and strain-level detection and identification and for characterization of environmentally relevant, metabolically diverse bacteria. Proteomics-based approaches represent an emerging complement to traditional methods of characterizing microorganisms, enabling the elucidation of the expressed biomarkers of genome sequence information, which can be applied to 'proteotyping' applications of microorganisms at all taxonomic levels. (C) 2015 Elsevier GmbH. All rights reserved.
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