scholarly journals Biodiversity of Denitrifying and Dinitrogen-Fixing Bacteria in an Acid Forest Soil

2002 ◽  
Vol 68 (8) ◽  
pp. 3818-3829 ◽  
Author(s):  
Christopher Rösch ◽  
Alexander Mergel ◽  
Hermann Bothe
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Nitrite Reductase ◽  
Pcr Amplification ◽  
Rrna Gene ◽  
Cloning And Sequencing ◽  
Genetic Traits ◽  
Uncultured Bacteria ◽  
Pcr Products ◽  
The 16S Rrna Gene

ABSTRACT Isolated soil DNA from an oak-hornbeam forest close to Cologne, Germany, was suitable for PCR amplification of gene segments coding for the 16S rRNA and nitrogenase reductase (NifH), nitrous oxide reductase (NosZ), cytochrome cd 1-containing nitrite reductase (NirS), and Cu-containing nitrite reductase (NirK) of denitrification. For each gene segment, diverse PCR products were characterized by cloning and sequencing. None of the 16S rRNA gene sequences was identical to any deposited in the data banks, and therefore each of them belonged to a noncharacterized bacterium. In contrast, the analyzed clones of nifH gave only a few different sequences, which occurred many times, indicating a low level of species richness in the N2-fixing bacterial population in this soil. Identical nifH sequences were also detected in PCR amplification products of DNA of a soil approximately 600 km distant from the Cologne area. Whereas biodiversity was high in the case of nosZ, only a few different sequences were obtained with nirK. With respect to nirS, cloning and sequencing of the PCR products revealed that many false gene segments had been amplified with DNA from soil but not from cultured bacteria. With the 16S rRNA gene data, many sequences of uncultured bacteria belonging to the Acidobacterium phylum and actinomycetes showed up in the PCR products when isolated DNA was used as the template, whereas sequences obtained for nifH and for the denitrification genes were closely related to those of the proteobacteria. Although in such an experimental approach one has to cope with the enormous biodiversity in soils and only a few PCR products can be selected at random, the data suggest that denitrification and N2 fixation are not genetic traits of most of the uncultured bacteria.

scholarly journals Nonspecific PCR Amplification of the 16S rRNA Gene Segment in Different Bacteria by Use of Primers Specific for Campylobacter, Arcobacter, and Helicobacter spp.

2007 ◽  
Vol 45 (4) ◽  
pp. 1376-1377 ◽  
Author(s):  
A. D. Raut ◽  
B. P. Kapadnis ◽  
R. Shashidhar ◽  
J. R. Bandekar ◽  
P. Vaishampayan ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Gene Segment ◽  
Pcr Amplification ◽  
Rrna Gene ◽  
The 16S Rrna Gene

scholarly journals Six species of non-tuberculosis mycobacteria carry non-identical 16S rRNA gene copies

2018 ◽  
Author(s):  
Keita Takeda ◽  
Kinuyo Chikamatsu ◽  
Yuriko Igarashi ◽  
Yuta Morishige ◽  
Yoshiro Murase ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Rrna Gene ◽  
Target Sequence ◽  
Nucleotide Polymorphisms ◽  
16S Rrna Gene Sequences ◽  
Cloning And Sequencing ◽  
Single Nucleotide ◽  
Gene Copies ◽  
The 16S Rrna Gene

AbstractNon-tuberculosis mycobacteria (NTM) can carry two or more 16S rRNA gene copies that are, in some instances, non-identical. In this study, we used a combined cloning and sequencing approach to analyze the 16S rRNA gene sequences of six NTM species,Mycobacterium cosmeticum, M. pallens, M. hodleri, M. crocinum, M. flavescens, andM. xenopi. The approach facilitated the identification of two distinct gene copies in each species. The twoM. cosmeticumgenes had a single nucleotide difference, whereas two nucleotide polymorphisms were identified inM. hodleri, M. flavescens, andM. xenopi. M. pallenshad a difference in four nucleotides andM. crocinumin 23. Hence, we showed that the six NTM species possess at least two non-identical 16S rRNA gene copies.ImportanceThe presence of multiple 16S rRNA gene copies with nucleotide polymorphisms represents a challenge for species identification using 16S rRNA as the target sequence. Our analysis was focused on six NTM species,M. cosmeticum, M. pallens, M. hodleri, M. crocinum, M. flavescens, andM. xenopi. As a result, we generated the full-length sequences of two non-identical 16S rRNA copies for each NTM species. The data will be helpful for the sequence analysis of specimens or other samples.

‘Candidatus Liberibacter americanus’, associated with citrus huanglongbing (greening disease) in São Paulo State, Brazil

2005 ◽  
Vol 55 (5) ◽  
pp. 1857-1862 ◽  
Author(s):  
Diva do Carmo Teixeira ◽  
Colette Saillard ◽  
Sandrine Eveillard ◽  
Jean Luc Danet ◽  
Paulo Inácio da Costa ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Gene Sequence ◽  
Pcr Amplification ◽  
Rrna Gene ◽  
Rrna Gene Sequence ◽  
Gene Sequences ◽  
16S Rrna Gene Sequences ◽  
Intergenic Regions ◽  
The 16S Rrna Gene

Symptoms of huanglongbing (HLB) were reported in São Paulo State (SPS), Brazil, in March 2004. In Asia, HLB is caused by ‘Candidatus Liberibacter asiaticus' and in Africa by ‘Candidatus Liberibacter africanus’. Detection of the liberibacters is based on PCR amplification of their 16S rRNA gene with specific primers. Leaves with blotchy mottle symptoms characteristic of HLB were sampled in several farms of SPS and tested for the presence of liberibacters. ‘Ca. L. asiaticus' was detected in a small number of samples but most samples gave negative PCR results. Therefore, a new HLB pathogen was suspected. Evidence for an SPS-HLB bacterium in symptomatic leaves was obtained by PCR amplification with universal primers for prokaryotic 16S rRNA gene sequences. The amplified 16S rRNA gene was cloned and sequenced. Sequence analysis and phylogeny studies showed that the 16S rRNA gene possessed the oligonucleotide signatures and the secondary loop structure characteristic of the α-Proteobacteria, including the liberibacters. The 16S rRNA gene sequence phylogenetic tree showed that the SPS-HLB bacterium clustered within the α-Proteobacteria, the liberibacters being its closest relatives. For these reasons, the SPS-HLB bacterium is considered a member of the genus ‘Ca. Liberibacter’. However, while the 16S rRNA gene sequences of ‘Ca. L. asiaticus' and ‘Ca. L. africanus' had 98·4 % similarity, the 16S rRNA gene sequence of the SPS-HLB liberibacter had only 96·0 % similarity with the 16S rRNA gene sequences of ‘Ca. L. asiaticus' or ‘Ca. L. africanus’. This lower similarity was reflected in the phylogenetic tree, where the SPS-HLB liberibacter did not cluster within the ‘Ca. L asiaticus’/‘Ca. L. africanus group’, but as a separate branch. Within the genus ‘Candidatus Liberibacter’ and for a given species, the 16S/23S intergenic region does not vary greatly. The intergenic regions of three strains of ‘Ca. L. asiaticus’, from India, the People's Republic of China and Japan, were found to have identical or almost identical sequences. In contrast, the intergenic regions of the SPS-HLB liberibacter, ‘Ca. L. asiaticus' and ‘Ca. L. africanus' had quite different sequences, with similarity between 66·0 and 79·5 %. These results confirm that the SPS-HLB liberibacter is a novel species for which the name ‘Candidatus Liberibacter americanus' is proposed. Like the African and the Asian liberibacters, the ‘American’ liberibacter is restricted to the sieve tubes of the citrus host. The liberibacter could also be detected by PCR amplification of the 16S rRNA gene in Diaphorina citri, the psyllid vector of ‘Ca. L. asiaticus’, suggesting that this psyllid is also a vector of ‘Ca. L. americanus' in SPS. ‘Ca. L. americanus' was detected in 216 of 218 symptomatic leaf samples from 47 farms in 35 municipalities, while ‘Ca. L. asiaticus' was detected in only 4 of the 218 samples, indicating that ‘Ca. L. americanus' is the major cause of HLB in SPS.

scholarly journals Occurrence of a 16SrII-V Subgroup Phytoplasma Associated with Witches’-Broom Disease in Melochia corchorifolia in China

Plant Disease ◽  
2021 ◽  
Author(s):  
Shao-shuai Yu ◽  
Yuan Wu ◽  
Wei wei Song
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Rrna Gene ◽  
Rapid Extraction ◽  
Phytoplasma Strain ◽  
Tephrosia Purpurea ◽  
Plant Samples ◽  
Pcr Products ◽  
Broom Disease ◽  
The 16S Rrna Gene

Melochia corchorifolia L. is a plant belonging to the family Sterculiaceae, extracts from this plant have been reported to inhibit melanogenesis (Yuan et al., 2020). During September to November 2020, the plants showing abnormal symptoms including witches’-broom, leaf chlorosis, leaflet and internode shortening (Fig.1), were found in Dingan county of Hainan province, China, with about 50% infection rates in the field. The disease symptoms were suspected to be caused by the phytoplasma, a plant pathogenic prokaryotes that could not be cultured in vitro. Aiming to confirm the pathogen causing the symptoms, total DNA of the symptomatic or asymptomatic Melochia corchorifolia samples were extracted by CTAB method (Doyle and Doyle, 1990) using 0.10 g fresh plant leaves using the rapid extraction kit for plant genomic DNA (CTAB Plant Genome DNA Rapid Extraction Kit, Aidlab Biotechnologies Co., Ltd, Beijing, China). PCR reactions were performed using primers R16mF2/R16mR1 (Gundersen and Lee, 1996) specific for phytoplasma 16S rRNA gene fragments. PCR products of phytoplasma 16S rRNA gene sequences were obtained from the ten symptomatic plant samples but not from the DNA of the asymptomatic plant samples. The PCR products were cloned and sequenced by Biotechnology (Shanghai) Co., Ltd. (Shanghai, China) and the data were deposited in GenBank. The sequences of 16S rRNA gene fragments amplified from the DNA extracted from the disease plant samples were all identical, with a length of 1336 bp for the 16S rRNA (GenBank accession: MZ353520). Nucleotide Blast search based on the 16S rRNA gene fragment of the phytoplasma strain showed 100% sequence identities with that of 16SrII peanut witches’-broom group members, such as Cassava witches’-broom phytoplasma (KM280679), Cleome sp. phytoplasma (KM280677), Tephrosia purpurea witches’-broom phytoplasma (MW616560), Desmodium triflorum little leaf phytoplasma (MT452308) and Peanut witches’-broom phytoplasma (JX403944). Analysis of the 16S rRNA gene sequence of McWB-hnda strain by interactive online phytoplasma classification tool iPhyClassifier (Zhao et al., 2009) indicated that the phytoplasma strain is a member of 16SrII-V subgroup. The phytoplasma strain was named as Melochia corchorifolia witches’-broom (McWB) phytoplasma, McWB-hnda strain. Phylogenetic analysis performed by MEGA 7.0 employing neighbor-joining (NJ) method with 1000 bootstrap value (Kumar et al., 2016) indicated that the McWB-hnda phytoplasma strain was clustered into one clade with the phytoplasma strains of Tephrosia purpurea witches’-broom, Cleome sp., Peanut witches’-broom, Cassava witches’-broom and Desmodium triflorum little leaf with 97 % bootstrap value (Fig.2); McWB-hnda phytoplasma strain identified in the study and Melochia corchorifolia phyllody phytoplasma strain (KX150461) belonging to 16SrI-B subgroup previously identified in the Hainan Island of China by Chen et al. (2017) are in two independent clades(Fig.2). To our knowledge, this is the first report of a 16SrII-V subgroup phytoplasma associated with Melochia corchorifolia witches’-broom disease in Hainan Province, a tropical island of China. The phytoplasma strain identified in the study was relatively close to 16SrII peanut witches’-broom group phytoplasma strains associated with witches’-broom or little leaf diseases in the plants like Peanut, Tephrosia purpurea, Cassava and Desmodium triflorum. Our finding in the study indicated that Melochia corchorifolia may act as an alternative natural host not only for 16SrI-B subgroup phytoplasma but also for 16SrII-V subgroup phytoplasma, which would contribute to the spreading of the related phytoplasma diseases.

Detection of Mycoplasma gallinaceum by PCR amplification of the 16S rRNA gene from respiratory disease in village chickens

2018 ◽  
Author(s):  
P. Ponnusamy ◽  
T. Lurthu Reetha ◽  
B.S.M. Ronald ◽  
B. Puvarajan and R. Manicakm
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Respiratory Disease ◽  
Tamil Nadu ◽  
Abdominal Cavity ◽  
Pcr Amplification ◽  
Mycoplasma Species ◽  
Rrna Gene ◽  
Village Chickens ◽  
The 16S Rrna Gene

In the present study, Mycoplasma gallinaceum was detected by PCR amplification of 16S rRNA gene from chronic respiratory disease in village chickens of Cauvery delta region of Tamil Nadu. Necropsy was performed to find out the etiological agent in desi birds mortality. At necropsy, airsacculitis with caseous exudate were found in the thoracic and abdominal cavity. Caseous material from airsacs was collected aseptically from dead birds for detection of Mycoplasma species. DNA was extracted from caseous material by using tissue DNA extraction kit. PCR was carried out using primers to amplify 16S rRNA gene belonging to Mycoplasma species. The amplified product yielded approximately 700-bp length (703 to 713 bp) of the 16S rRNA gene specific for Mycoplasma species. Further, it was subjected to sequence analysis and confirmed as Mycoplasma gallinaceum by NCBI blast analysis. In the present communication, detection of M. gallinaceum by PCR amplification of 16S rRNA gene provides a powerful tool for rapid diagnosis. 

scholarly journals Asaia sp., an Unusual Spoilage Organism of Fruit-Flavored Bottled Water

2002 ◽  
Vol 68 (8) ◽  
pp. 4130-4131 ◽  
Author(s):  
John E. Moore ◽  
Mark McCalmont ◽  
Jiru Xu ◽  
B. Cherie Millar ◽  
Neville Heaney
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Molecular Identification ◽  
Bacterial Overgrowth ◽  
Pcr Amplification ◽  
Acetic Acid Bacteria ◽  
Bottled Water ◽  
Rrna Gene ◽  
Identification Techniques ◽  
The 16S Rrna Gene

ABSTRACT A gram-negative bacillus was isolated from a batch of fruit-flavored bottled water, which had spoiled as a result of bacterial overgrowth (>106 CFU/ml). The spoilage organism was extremely difficult to identify phenotypically and was poorly identified as Pasturella sp. (78.7% identification profile) employing the API 20NE identification scheme, which gave the profile 5040000. Molecular identification through PCR amplification of a partial region of the 16S rRNA gene followed by direct automated sequencing of the PCR amplicon allowed identification of the organism. Due to the sequence identity (100%) between the spoilage organism and a reference strain in GenBank, the spoilage isolate was considered to be an Asaia sp., a recently described genus and member of the acetic acid bacteria. This is the first report of Asaia sp. causing spoilage of a foodstuff and highlights the benefits of molecular identification techniques based on 16S rRNA gene sequences in the identification of unusual spoilage organisms.

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