scholarly journals Diversity of Transcripts of Nitrite Reductase Genes (nirK and nirS) in Rhizospheres of Grain Legumes

2005 ◽  
Vol 71 (4) ◽  
pp. 2001-2007 ◽  
Author(s):  
Shilpi Sharma ◽  
Manish Kumar Aneja ◽  
Jochen Mayer ◽  
Jean Charles Munch ◽  
Michael Schloter
Keyword(s):  
Denaturing Gradient Gel Electrophoresis ◽  
Lupinus Albus ◽  
Grain Legumes ◽  
Rt Pcr ◽  
Insert Size ◽  
Reverse Transcription Pcr ◽  
Distinct Cluster ◽  
Nitrite Reductases ◽  
Pcr Products ◽  
Gradient Gel Electrophoresis

ABSTRACT Transcription of the nirK and nirS genes coding for dissimilatory bacterial nitrite reductases was analyzed by reverse transcription PCR (RT-PCR) of mRNA isolated from rhizosphere samples of three economically important grain legumes at maturity: Vicia faba, Lupinus albus, and Pisum sativum. The nirK gene and transcripts could be detected in all the rhizosphere samples. In contrast, nirS could not be detected. Sampling variations were analyzed by comparing denaturing gradient gel electrophoresis profiles derived from nirK RT-PCR products. High similarity was observed between the replicates, and so one representative product per legume was cloned. Clones with the correct insert size were screened by restriction fragment length polymorphism by using the restriction enzyme MspI. The clones could be distributed into 12 different patterns. Patterns 1, 3, 4, 5, and 7 were common in clone libraries of the three rhizosphere types under study. Patterns 2, 9, 10, and 11 were absent from Pisum rhizospheres, while patterns 6, 8, and 12 were absent from the Vicia library. Pattern 1, which was the most dominant in the Vicia and Lupinus libraries, constituted about 25% of all clones. The Lupinus library had clones representing all 12 patterns, indicating it to be the most diverse among the three. Clones representative of each pattern were sequenced. All patterns grouped together forming a distinct cluster, which was divergent from previously described nirK sequences in the database. The study revealed a hitherto unknown diversity of denitrifiers in legume rhizospheres. A plant-dependent rhizosphere effect on the transcripts of a gene was evident.

scholarly journals Molecular Analysis of Ammonia-Oxidizing Bacteria of the β Subdivision of the Class Proteobacteria in Compost and Composted Materials

1999 ◽  
Vol 65 (2) ◽  
pp. 396-403 ◽  
Author(s):  
George A. Kowalchuk ◽  
Zinaida S. Naoumenko ◽  
Piet J. L. Derikx ◽  
Andreas Felske ◽  
John R. Stephen ◽  
...  
Keyword(s):  
Denaturing Gradient Gel Electrophoresis ◽  
Ammonia Oxidizer ◽  
Ammonia Oxidizing Bacteria ◽  
Nitrogen Transformations ◽  
Rt Pcr ◽  
Gene Encoding ◽  
Specific Pcr ◽  
Pcr Products ◽  
Gradient Gel Electrophoresis ◽  
Almost All

ABSTRACT Although the practice of composting animal wastes for use as biofertilizers has increased in recent years, little is known about the microorganisms responsible for the nitrogen transformations which occur in compost and during the composting process. Ammonia is the principle available nitrogenous compound in composting material, and the conversion of this compound to nitrite in the environment by chemolithotrophic ammonia-oxidizing bacteria is an essential step in nitrogen cycling. Therefore, the distribution of ammonia-oxidizing members of the β subdivision of the class Proteobacteriain a variety of composting materials was assessed by amplifying 16S ribosomal DNA (rDNA) and 16S rRNA by PCR and reverse transcriptase PCR (RT-PCR), respectively. The PCR and RT-PCR products were separated by denaturing gradient gel electrophoresis (DGGE) and were identified by hybridization with a hierarchical set of oligonucleotide probes designed to detect ammonia oxidizer-like sequence clusters in the genera Nitrosospira and Nitrosomonas. Ammonia oxidizer-like 16S rDNA was detected in almost all of the materials tested, including industrial and experimental composts, manure, and commercial biofertilizers. A comparison of the DGGE and hybridization results after specific PCR and RT-PCR suggested that not all of the different ammonia oxidizer groups detected in compost are equally active. amoA, the gene encoding the active-site-containing subunit of ammonia monooxygenase, was also targeted by PCR, and template concentrations were estimated by competitive PCR. Detection of ammonia-oxidizing bacteria in the composts tested suggested that such materials may not be biologically inert with respect to nitrification and that the fate of nitrogen during composting and compost storage may be affected by the presence of these organisms.

scholarly journals Denaturing Gradient Gel Electrophoresis Analysis of the 16S rRNA Gene V1 Region To Monitor Dynamic Changes in the Bacterial Population during Fermentation of Italian Sausages

2001 ◽  
Vol 67 (11) ◽  
pp. 5113-5121 ◽  
Author(s):  
Luca Cocolin ◽  
Marisa Manzano ◽  
Carlo Cantoni ◽  
Giuseppe Comi
Keyword(s):  
Gel Electrophoresis ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Rrna Gene ◽  
Dynamic Changes ◽  
Good Tool ◽  
Reverse Transcription Pcr ◽  
Dna And Rna ◽  
Fermented Sausages ◽  
Brochothrix Thermosphacta ◽  
Gradient Gel Electrophoresis

ABSTRACT In this study, a PCR-denaturing gradient gel electrophoresis (DGGE) protocol was used to monitor the dynamic changes in the microbial population during ripening of natural fermented sausages. The method was first optimized by using control strains from international collections, and a natural sausage fermentation was studied by PCR-DGGE and traditional methods. Total microbial DNA and RNA were extracted directly from the sausages and subjected to PCR and reverse transcription-PCR, and the amplicons obtained were analyzed by DGGE. Lactic acid bacteria (LAB) were present together with other organisms, mainly members of the family Micrococcaceae and meat contaminants, such as Brochothrix thermosphacta andEnterococcus sp., during the first 3 days of fermentation. After 3 days, LAB represented the main population, which was responsible for the acidification and proteolysis that determined the characteristic organoleptic profile of the Friuli Venezia Giulia fermented sausages. The PCR-DGGE protocol for studying sausage fermentation proved to be a good tool for monitoring the process in real time, and it makes technological adjustments possible when they are required.

Nitrifier and denitrifier molecular operational taxonomic unit compositions from sites of a freshwater estuary of Chesapeake Bay

2009 ◽  
Vol 55 (3) ◽  
pp. 333-346 ◽  
Author(s):  
Caroline S. Fortunato ◽  
David B. Carlini ◽  
Evan Ewers ◽  
Karen L. Bushaw-Newton
Keyword(s):  
Organic Matter ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Organic Matter Content ◽  
Sequence Divergence ◽  
Operational Taxonomic Unit ◽  
Matter Content ◽  
Ammonia Oxidizing Bacteria ◽  
Overlying Water ◽  
Pcr Products ◽  
Gradient Gel Electrophoresis

Temporal and spatial changes in the molecular operational taxonomic unit (OTU) compositions of bacteria harboring genes for nitrification and denitrification were assessed using denaturing gradient gel electrophoresis (DGGE), clone-based DNA sequencing of selected PCR products, and analyses of ammonium and organic matter concentrations. Sediment, overlying water, and pore-water samples were taken from different vegetated sites of Jug Bay National Estuarine Research Reserve, Maryland, during spring, summer, and fall 2006. OTU richness and the diversities of nitrifiers and denitrifiers were assessed by the presence of bands on DGGE gels, both ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) were seasonally dependent. AOB OTU richness was highest in the summer when NOB richness was decreased, whereas NOB richness was highest in the spring when AOB richness was decreased. The OTU diversities of nitrifiers did not correlate with ammonium concentrations, organic matter concentrations, or the presence of vegetation. The OTU diversities of denitrifiers possessing either the nirK or nosZ genes were not seasonally dependent but were positively correlated with organic matter content (p = 0.0015, r2 = 0.27; p < 0.0001, r2 = 0.39, respectively). Additionally, the presence of vegetation significantly enhanced nosZ species richness (Wilcoxon/Kruskal–Wallis test, p < 0.008), but this trend was not seen for nirK OTU richness. Banding patterns for nirK OTUs were more similar within sites for each season compared with any of the other genes. Over all seasons, nirK OTU richness was highest and AOB and nosZ OTU richness were lowest (Wilcoxon/Kruskal–Wallis test, p < 0.0001). High levels of sequence divergence among cloned nirK PCR products indicate a broad diversity of nirK homologs in this freshwater estuary.

scholarly journals Anaerobic Biodegradation of n-Hexadecane by a Nitrate-Reducing Consortium

2008 ◽  
Vol 75 (5) ◽  
pp. 1339-1344 ◽  
Author(s):  
Amy V. Callaghan ◽  
Meghan Tierney ◽  
Craig D. Phelps ◽  
L. Y. Young
Keyword(s):  
Denaturing Gradient Gel Electrophoresis ◽  
Mass Spectrometry Analysis ◽  
Chain Elongation ◽  
Gas Chromatography Mass Spectrometry ◽  
Rrna Gene ◽  
Pentadecanoic Acid ◽  
Spectrometry Analysis ◽  
Tridecanoic Acid ◽  
Pcr Products ◽  
Gradient Gel Electrophoresis

ABSTRACT Nitrate-reducing enrichments, amended with n-hexadecane, were established with petroleum-contaminated sediment from Onondaga Lake. Cultures were serially diluted to yield a sediment-free consortium. Clone libraries and denaturing gradient gel electrophoresis analysis of 16S rRNA gene community PCR products indicated the presence of uncultured alpha- and betaproteobacteria similar to those detected in contaminated, denitrifying environments. Cultures were incubated with H34-hexadecane, fully deuterated hexadecane (d 34-hexadecane), or H34-hexadecane and NaH13CO3. Gas chromatography-mass spectrometry analysis of silylated metabolites resulted in the identification of [H29]pentadecanoic acid, [H25]tridecanoic acid, [1-13C]pentadecanoic acid, [3-13C]heptadecanoic acid, [3-13C]10-methylheptadecanoic acid, and d 27-pentadecanoic, d 25-, and d 2 4-tridecanoic acids. The identification of these metabolites suggests a carbon addition at the C-3 position of hexadecane, with subsequent β-oxidation and transformation reactions (chain elongation and C-10 methylation) that predominantly produce fatty acids with odd numbers of carbons. Mineralization of [1-14C]hexadecane was demonstrated based on the recovery of 14CO2 in active cultures.

scholarly journals Bifidobacterial Diversity in Human Feces Detected by Genus-Specific PCR and Denaturing Gradient Gel Electrophoresis

2001 ◽  
Vol 67 (2) ◽  
pp. 504-513 ◽  
Author(s):  
Reetta M. Satokari ◽  
Elaine E. Vaughan ◽  
Antoon D. L. Akkermans ◽  
Maria Saarela ◽  
Willem M. de Vos
Keyword(s):  
16S Rdna ◽  
Gel Electrophoresis ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Methodological Approach ◽  
Common Species ◽  
Bifidobacterium Adolescentis ◽  
Specific Pcr ◽  
Rdna Sequences ◽  
Pcr Products ◽  
Gradient Gel Electrophoresis

ABSTRACT We describe the development and validation of a method for the qualitative analysis of complex bifidobacterial communities based on PCR and denaturing gradient gel electrophoresis (DGGE).Bifidobacterium genus-specific primers were used to amplify an approximately 520-bp fragment from the 16S ribosomal DNA (rDNA), and the fragments were separated in a sequence-specific manner in DGGE. PCR products of the same length from different bifidobacterial species showed good separation upon DGGE. DGGE of fecal 16S rDNA amplicons from five adult individuals showed host-specific populations of bifidobacteria that were stable over a period of 4 weeks. Sequencing of fecal amplicons resulted in Bifidobacterium-like sequences, confirming that the profiles indeed represent the bifidobacterial population of feces. Bifidobacterium adolescentis was found to be the most common species in feces of the human adult subjects in this study. The methodological approach revealed intragenomic 16S rDNA heterogeneity in the type strain of B. adolescentis, E-981074. The strain was found to harbor five copies of 16S rDNA, two of which were sequenced. The two 16S rDNA sequences of B. adolescentis E-981074T exhibited microheterogeneity differing in eight positions over almost the total length of the gene.

scholarly journals Molecular Profiling of the Clostridium leptum Subgroup in Human Fecal Microflora by PCR-Denaturing Gradient Gel Electrophoresis and Clone Library Analysis

2006 ◽  
Vol 72 (8) ◽  
pp. 5232-5238 ◽  
Author(s):  
Jian Shen ◽  
Baorang Zhang ◽  
Guifang Wei ◽  
Xiaoyan Pang ◽  
Hua Wei ◽  
...  
Keyword(s):  
Clone Library ◽  
Gel Electrophoresis ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Rrna Gene ◽  
Specific Pcr ◽  
Clone Library Analysis ◽  
Pcr Products ◽  
Gradient Gel Electrophoresis ◽  
Universal Bacterial Primer ◽  
Group Specific Primer

ABSTRACT A group-specific PCR-based denaturing gradient gel electrophoresis (DGGE) method was developed and combined with group-specific clone library analysis to investigate the diversity of the Clostridium leptum subgroup in human feces. PCR products (length, 239 bp) were amplified using C. leptum cluster-specific primers and were well separated by DGGE. The DGGE patterns of fecal amplicons from 11 human individuals revealed host-specific profiles; the patterns for fecal samples collected from a child for 3 years demonstrated the structural succession of the population in the first 2 years and its stability in the third year. A clone library was constructed with 100 clones consisting of 1,143-bp inserts of 16S rRNA gene fragments that were amplified from one adult fecal DNA with one forward universal bacterial primer and one reverse group-specific primer. Eighty-six of the clones produced the 239-bp C. leptum cluster-specific amplicons, and the remaining 14 clones did not produce these amplicons but still phylogenetically belong to the subgroup. Sixty-four percent of the clones were related to Faecalibacterium prausnitzii (similarity, 97 to 99%), 6% were related to Subdoligranulum variabile (similarity, ∼99%), 2% were related to butyrate-producing bacterium A2-207 (similarity, 99%), and 28% were not identified at the species level. The identities of most bands in the DGGE profiles for the same adult were determined by comigration analysis with the 86 clones that harbored the 239-bp group-specific fragments. Our results suggest that DGGE combined with clone library analysis is an effective technique for monitoring and analyzing the composition of this important population in the human gut flora.

scholarly journals First Cases of SARS-CoV-2 in Iran, 2020: Case Series Report

2020 ◽  
Author(s):  
Jila YAVARIAN ◽  
Nazanin-Zahra SHAFIEI-JANDAGHI ◽  
Kaveh SADEGHI ◽  
Somayeh SHATIZADEH MALEKSHAHI ◽  
Vahid SALIMI ◽  
...  
Keyword(s):  
Throat Swab ◽  
Case Series ◽  
Future Research ◽  
Rt Pcr ◽  
Reverse Transcription Pcr ◽  
Pcr Products ◽  
Case Series Report ◽  
E Region ◽  
Novel Coronavirus ◽  
Series Report

In Jan 2020, the outbreak of the 2019 novel coronavirus (SARS-CoV-2) in Wuhan, Hubei Province of China spread increasingly to other countries worldwide which WHO declared it as a public health emergency of international concern. Iran was included in the affected countries. Throat swab specimens were collected and tested by using real-time reverse transcription PCR (RT-PCR) kit targeting the E region for screening and RNA dependent RNA polymerase for confirmation. Conventional RT-PCR was conducted for the N region and the PCR products were sequenced by Sanger sequencing. The first seven cases of SARS-CoV-2 infections were identified in Qom, Iran. This report describes the clinical and epidemiological features of the first cases of SARS-CoV-2 confirmed in Iran. Future research should focus on finding the routes of transmission for this virus, including the possibility of transmission from foreign tourists to identify the possible origin of SARS-CoV-2 outbreak in Iran.

scholarly journals Direct Identification in Food Samples of Listeria spp. and Listeria monocytogenes by Molecular Methods

2002 ◽  
Vol 68 (12) ◽  
pp. 6273-6282 ◽  
Author(s):  
Luca Cocolin ◽  
Kalliopi Rantsiou ◽  
Lucilla Iacumin ◽  
Carlo Cantoni ◽  
Giuseppe Comi
Keyword(s):  
Listeria Monocytogenes ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Direct Detection ◽  
Pcr Amplification ◽  
Food Samples ◽  
Detection And Identification ◽  
Optimized Protocol ◽  
Pcr Products ◽  
Gradient Gel Electrophoresis ◽  
Species Specific

ABSTRACT A new molecular approach for the detection and identification of Listeria spp. and Listeria monocytogenes in food is presented here. The method is based on the PCR amplification of a fragment of the iap gene from the five species belonging to the genus and on the analysis of the PCR products obtained by denaturing gradient gel electrophoresis (DGGE). The protocol was first optimized by using strains from international collections. Based on the differences present in the sequences amplified, it was possible to obtain species-specific DGGE migration that allowed fast and easy identification of L. monocytogenes, L. innocua, L. welshimeri, L. seeligeri, and L. ivanovii. Moreover, for L. monocytogenes serotypes, partial differentiation was possible. The optimized protocol was used for identification of Listeria strains traditionally isolated from food and for direct detection and identification of Listeria members in food after an overnight enrichment. Identification of 48 food isolates and direct detection of Listeria spp. in 73 food samples show the potential of the method that can be used as a fast screening test to investigate the presence of Listeria spp. and L. monocytogenes in food.

scholarly journals Comparison of pmoA PCR Primer Sets as Tools for Investigating Methanotroph Diversity in Three Danish Soils

2001 ◽  
Vol 67 (9) ◽  
pp. 3802-3809 ◽  
Author(s):  
David G. Bourne ◽  
Ian R. McDonald ◽  
J. Colin Murrell
Keyword(s):  
Fragment Length Polymorphism ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Methane Monooxygenase ◽  
Open Reading Frames ◽  
Pcr Products ◽  
Gradient Gel Electrophoresis ◽  
Primer Sets ◽  
Atmospheric Concentrations ◽  
Reading Frames ◽  
Pcr Primer

ABSTRACT Three particulate methane monooxygenase PCR primer sets (A189-A682, A189-A650, and A189-mb661) were investigated for their ability to assess methanotroph diversity in soils from three sites, i.e., heath, oak, and sitka, each of which was capable of oxidizing atmospheric concentrations of methane. Each PCR primer set was used to construct a library containing 50 clones from each soil type. The clones from each library were grouped by restriction fragment length polymorphism, and representatives from each group were sequenced and analyzed. Libraries constructed with the A189-A682 PCR primer set were dominated byamoA-related sequences or nonspecific PCR products with nonsense open reading frames. The primer set could not be used to assess methanotroph diversity in these soils. A newpmoA-specific primer, A650, was designed in this study. The A189-A650 primer set demonstrated distinct biases both in clone library analysis and when incorporated into denaturing gradient gel electrophoresis analysis. The A189-mb661 PCR primer set demonstrated the largest retrieval of methanotroph diversity of all of the primer sets. However, this primer set did not retrieve sequences linked with novel high-affinity methane oxidizers from the soil libraries, which were detected using the A189-A650 primer set. A combination of all three primer sets appears to be required to examine both methanotroph diversity and the presence of novel methane monooxygenase sequences.

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