Plantigrade settlement of the musselMytilus coruscusin response to natural biofilms on different surfaces

2014 ◽  
Vol 94 (8) ◽  
pp. 1639-1649 ◽  
Author(s):  
Jin-Long Yang ◽  
Xuan Zhou ◽  
Yi-Feng Li ◽  
Xing-Pan Guo ◽  
Xiao Liang ◽  
...  
Keyword(s):  
Surface Properties ◽  
Gel Electrophoresis ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Dry Weight ◽  
High Variability ◽  
Short Term ◽  
Gradient Gel Electrophoresis ◽  
Diatom Density ◽  
Insight Into ◽  
Natural Biofilms

Surface properties affect the attachment of micro- and macroscopic marine organisms. The current study examined the settlement response of the musselMytilus coruscusplantigrades to natural biofilms formed on surfaces of different wettability. The percentages of plantigrade settlement were not influenced by the biofilms formed on variously wettable surfaces in the short term, but after 10 days, the plantigrade settlement rates decreased on biofilms formed on lower wettability surfaces. In general, lower wettability of the surfaces resulted in the decrease of the dry weight, bacterial and diatom density and the thickness of natural biofilms when compared to high wettability surfaces. In contrast, chlorophyll-aconcentration in biofilms was independent of the initial wettability of the surfaces. Comparative cluster analysis of bacterial denaturing gradient gel electrophoresis patterns revealed that high variability existed between the bacterial community on high wettability surfaces and that on low wettability surfaces. Thus, surface wettability affects the formation of natural biofilms, and this variation in biofilms developed on different wettability surfaces may explain the discrepancy in their corresponding inducing activities onM. coruscusplantigrade settlement. This finding provides new insight into interactions between mussel settlement, biofilm characteristics and surface properties.

scholarly journals Heterogeneity of uidA gene in environmental Escherichia coli populations

2005 ◽  
Vol 3 (3) ◽  
pp. 297-304 ◽  
Author(s):  
Clarivel Lasalde ◽  
Roberto Rodriguez ◽  
Gary A. Toranzos ◽  
Henry H. Smith
Keyword(s):  
Escherichia Coli ◽  
Genetic Heterogeneity ◽  
Gel Electrophoresis ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Dry Weight ◽  
Source Tracking ◽  
Tropical Rain Forests ◽  
Rain Forests ◽  
E Coli ◽  
Gradient Gel Electrophoresis

Previous studies have shown that Escherichia coli can be isolated from non-polluted rivers and from bromeliad axilae in pristine areas of tropical rain forests. Finding E. coli in pristine environments is unusual because this bacterium is thought to only survive in the gut of warm-blooded animals and thus its presence should indicate recent fecal contamination. The aims of this study were 1) to determine if E. coli is part of the native soil microbiota in tropical rain forests and 2) to determine if genetic heterogeneity exists among E. coli populations. High concentrations of total coliforms (104–105 cells per 10 g of soil dry weight) and low concentrations of thermotolerant coliforms (101–102 cells per 10 g dry soil, the majority of these were found to be E. coli) were detected. PCR using uidA-specific primers was done on DNA purified from E. coli isolates and the resulting amplicons analysed by denaturing-gradient gel electrophoresis (DGGE). Out of several hundred isolates, mixtures of nine different amplicons were consistently observed. The different patterns of DGGE observed indicate that the E. coli populations in these pristine soils are genetically heterogeneous. Fecal and environmental E. coli isolates were also analysed by pulsed-field gel electrophoresis (PFGE) which showed high DNA sequence variation among the E. coli isolates. Because of these differences in the genomes, PFGE did not allow grouping of environmental versus human isolates of E. coli when compared side to side. The apparent genetic polymorphisms, as a result of genetic heterogeneity, observed in isolates from the same pristine site indicate that source tracking may be difficult to carry out using E. coli as the target organism.

scholarly journals Parenteral Antibiotics Reduce Bifidobacteria Colonization and Diversity in Neonates

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Séamus Hussey ◽  
Rebecca Wall ◽  
Emma Gruffman ◽  
Lisa O'Sullivan ◽  
C. Anthony Ryan ◽  
...  
Keyword(s):  
Antibiotic Treatment ◽  
Patient Group ◽  
Gel Electrophoresis ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Neonatal Period ◽  
Short Term ◽  
Parenteral Antibiotic ◽  
Gradient Gel Electrophoresis ◽  
Stool Samples ◽  
The Impact

We investigated the impact of parenteral antibiotic treatment in the early neonatal period on the evolution of bifidobacteria in the newborn. Nine babies treated with intravenous ampicillin/gentamicin in the first week of life and nine controls (no antibiotic treatment) were studied. Denaturing gradient gel electrophoresis was used to investigate the composition ofBifidobacteriumin stool samples taken at four and eight weeks. Bifidobacteria were detected in all control infants at both four and eight weeks, while only six of nine antibiotic-treated infants had detectable bifidobacteria at four weeks and eight of nine at eight weeks. Moreover, stool samples of controls showed greater diversity ofBifidobacteriumspp. compared with antibiotic-treated infants. In conclusion, short-term parenteral antibiotic treatment of neonates causes a disturbance in the expected colonization pattern of bifidobacteria in the first months of life. Further studies are required to probiotic determine if supplementation is necessary in this patient group.

scholarly journals Isolation of Methylophaga spp. from Marine Dimethylsulfide-Degrading Enrichment Cultures and Identification of Polypeptides Induced during Growth on Dimethylsulfide

2007 ◽  
Vol 73 (8) ◽  
pp. 2580-2591 ◽  
Author(s):  
Hendrik Schäfer
Keyword(s):  
Gel Electrophoresis ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Large Subunit ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Butyl Ether ◽  
Bacterial Populations ◽  
Enrichment Cultures ◽  
Gradient Gel Electrophoresis ◽  
Insight Into

ABSTRACT Dimethylsulfide (DMS)-degrading enrichment cultures were established from samples of coastal seawater, nonaxenic Emiliania huxleyi cultures, and mixed marine methyl halide-degrading enrichment cultures. Bacterial populations from a broad phylogenetic range were identified in the mixed DMS-degrading enrichment cultures by denaturing gradient gel electrophoresis (DGGE). Sequences of dominant DGGE bands were similar to those of members of the genera Methylophaga and Alcanivorax. Several closely related Methylophaga strains were obtained that were able to grow on DMS as the carbon and energy source. Roseobacter-related populations were detected in some of the enrichment cultures; however, none of the Roseobacter group isolates that were tested were able to grow on DMS. Oxidation of DMS by Methylophaga sp. strain DMS010 was not affected by addition of the inhibitor chloroform or methyl tert-butyl ether, suggesting that DMS metabolism may occur by a route different from those described for Thiobacillus species and other unidentified marine isolates. Addition of DMS and methanethiol to whole-cell suspensions of strain DMS010 induced oxygen uptake when strain DMS010 was grown on DMS but not in cells grown on methanol. The apparent Km s of strain DMS010 for DMS and for methanethiol were 2.1 and 4.6 μM, respectively, when grown on DMS. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the biomass of strain DMS010 and analysis of peptide bands by mass spectrometry techniques and N-terminal sequencing provided the first insight into the identity of polypeptides induced during growth on DMS. These included XoxF, a homolog of the large subunit of methanol dehydrogenase for which a biological role has not been identified previously.

Allelopathic and Medicinal plant. 26. Millettia speciosa

2020 ◽  
Vol 51 (2) ◽  
pp. 125-146
Author(s):  
Nasiruddin Nasiruddin ◽  
Yu Zhangxin ◽  
Ting Zhao Chen Guangying ◽  
Minghui Ji
Keyword(s):  
Community Structure ◽  
Medicinal Plant ◽  
Gel Electrophoresis ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Wiener Index ◽  
Pseudomonas Spp ◽  
Evenness Index ◽  
Gradient Gel Electrophoresis ◽  
Rhizosphere Pseudomonas

We grew cucumber in pots in greenhouse for 9-successive cropping cycles and analyzed the rhizosphere Pseudomonas spp. community structure and abundance by PCR-denaturing gradient gel electrophoresis and quantitative PCR. Results showed that continuous monocropping changed the cucumber rhizosphere Pseudomonas spp. community. The number of DGGE bands, Shannon-Wiener index and Evenness index decreased during the 3rd cropping and thereafter, increased up to the 7th cropping, however, however, afterwards they decreased again. The abundance of Pseudomonas spp. increased up to the 5th successive cropping and then decreased gradually. These findings indicated that the structure and abundance of Pseudomonas spp. community changed with long-term cucumber monocropping, which might be linked to soil sickness caused by its continuous monocropping.

scholarly journals Impact of Intensive Land-Based Fish Culture in Qingdao, China, on the Bacterial Communities in Surrounding Marine Waters and Sediments

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Qiufen Li ◽  
Yan Zhang ◽  
David Juck ◽  
Nathalie Fortin ◽  
Charles W. Greer
Keyword(s):  
Bacterial Communities ◽  
Gel Electrophoresis ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Fish Culture ◽  
Fish Ponds ◽  
Marine Area ◽  
Gradient Gel Electrophoresis ◽  
Reducing Bacteria ◽  
The Impact ◽  
Nitrate Reducing Bacteria

The impact of intensive land-based fish culture in Qingdao, China, on the bacterial communities in surrounding marine environment was analyzed. Culture-based studies showed that the highest counts of heterotrophic, ammonium-oxidizing, nitrifying, and nitrate-reducing bacteria were found in fish ponds and the effluent channel, with lower counts in the adjacent marine area and the lowest counts in the samples taken from 500 m off the effluent channel. Denaturing gradient gel electrophoresis (DGGE) analysis was used to assess total bacterial diversity. Fewer bands were observed from the samples taken from near the effluent channel compared with more distant sediment samples, suggesting that excess nutrients from the aquaculture facility may be reducing the diversity of bacterial communities in nearby sediments. Phylogenetic analysis of the sequenced DGGE bands indicated that the bacteria community of fish-culture-associated environments was mainly composed of Flavobacteriaceae, gamma- and deltaproteobacteria, including generaGelidibacter, Psychroserpen, Lacinutrix,andCroceimarina.

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