scholarly journals Pyrosequencing of Tagged 16S rRNA Gene Amplicons for Rapid Deciphering of the Microbiomes of Fermented Foods Such as Pearl Millet Slurries

2009 ◽  
Vol 75 (13) ◽  
pp. 4354-4361 ◽  
Author(s):  
Christèle Humblot ◽  
Jean-Pierre Guyot

ABSTRACT Pearl millet slurries, mixed with groundnuts or not, were chosen as a model to investigate the feasibility of obtaining a rapid overview of community structure and population dynamics of fermented foods using pyrosequencing of tagged 16S rRNA gene amplicons. From 14 fermented samples collected either in a traditional small-scale processing unit in Burkina Faso or at laboratory scale, 137,469 sequences of bacterial 16S rRNA gene amplicons were characterized. Except for a few Proteobacteria, almost all the bacterial sequences were attributed to cultivable bacteria. This approach enabled 80.7% of the sequences to be attributed to a family and 70% to a genus but did not enable identification to the species level. The bacterial sequences were assigned to four phyla, with Firmicutes representing the highest diversity, followed by Proteobacteria, Actinobacteria, and Bacteroidetes, which were found only in the slurries prepared in traditional production units. Most of the Firmicutes were lactic acid bacteria, mainly represented by members of the Lactobacillus, Pediococcus, Leuconostoc, and Weissella genera, whose ratio varied from the onset to the end of the fermentation. The other bacteria present at the beginning of fermentation were generally no longer detected at the end, which is consistent with already-known patterns in the microbial ecology of fermented foods. In conclusion, this method seems very promising for rapid and preliminary microbial characterization in many samples of an unknown food sample, by determining numerous nucleic sequences simultaneously without the need for cloning and cultivation-dependent methods.

2010 ◽  
Vol 76 (9) ◽  
pp. 2791-2798 ◽  
Author(s):  
Goh Nishitani ◽  
Satoshi Nagai ◽  
Katsuhisa Baba ◽  
Susumu Kiyokawa ◽  
Yuki Kosaka ◽  
...  

ABSTRACT We analyzed cryptophyte nucleomorph 18S rRNA gene sequences retained in natural Myrionecta rubra cells and plastid 16S rRNA gene and psbA sequences retained in natural cells of several Dinophysis species collected from Japanese coastal waters. A total of 715 nucleomorph sequences obtained from 134 M. rubra cells and 564 plastid 16S rRNA gene and 355 psbA sequences from 71 Dinophysis cells were determined. Almost all sequences in M. rubra and Dinophysis spp. were identical to those of Teleaulax amphioxeia, suggesting that M. rubra in Japanese coastal waters preferentially ingest T. amphioxeia. The remaining sequences were closely related to those of Geminigera cryophila and Teleaulax acuta. Interestingly, 37 plastid 16S rRNA gene sequences, which were different from T. amphioxeia and amplified from Dinophysis acuminata and Dinophysis norvegica cells, were identical to the sequence of a D. acuminata cell found in the Greenland Sea, suggesting that a widely distributed and unknown cryptophyte species is also preyed upon by M. rubra and subsequently sequestered by Dinophysis. To confirm the reliability of molecular identification of the cryptophyte Teleaulax species detected from M. rubra and Dinophysis cells, the nucleomorph and plastid genes of Teleaulax species isolated from seawaters were also analyzed. Of 19 isolates, 16 and 3 clonal strains were identified as T. amphioxeia and T. acuta, respectively, and no sequence variation was confirmed within species. T. amphioxeia is probably the primary source of prey for M. rubra in Japanese coastal waters. An unknown cryptophyte may serve as an additional source, depending on localities and seasons.


2007 ◽  
Vol 22 (4) ◽  
pp. 266-271 ◽  
Author(s):  
J. F. Siqueira ◽  
I. N. Rôças ◽  
S. S. M. Paiva ◽  
K. M. Magalhães ◽  
T. Guimarães-Pinto

2022 ◽  
Vol 16 (1) ◽  
pp. 102
Author(s):  
Nur Alifah Ilyana Mohamad Naim ◽  
Nabihah Raihanah Tajul Anuar ◽  
Lyena Watty Zuraine Ahmad ◽  
Roziah Kambol ◽  
Sharifah Aminah Syed Mohamad ◽  
...  

The 16S rRNA gene is a housekeeping genetic marker that is available in almost all bacterial species and it is used in bacterial phylogeny and taxonomy studies. In many studies, the 16S rRNA gene is used in identification of certain bacterial species. Being a less conserved genetic marker, certain studies found it is a useful tool to infer the genome-wide similarity levels among the closely related prokaryotic organisms. Thus, this study aimed to compare the variation in the 16S rRNA partial region of Burkholderia spp. that infect the panicle of rice from eight different geographical areas. 58 sequences with total of 688 base pairs (bp) of 16S rRNA gene in B. glumae and B. gladioli were retrieved from public database based on several countries namely United State, Panama, Ecuador, Thailand, China, India, Korea and Malaysia. Then, the data sequences were analysed and validated using MEGAX and ABGD software respectively. The result of phylogenetic tree confirmed that B. glumae and B. gladioli were species that present in the panicle blight of rice. However, Data Analysis in Molecular Biology and Evolution (DAMBE) and Automatic Barcode Gap Discovery (ABGD) software were not able to detect substitution saturation and divergence between B. glumae and B. gladioli respectively based on the 58 sequences of the 16S rRNA partial region. Hence, it proves that 16S rRNA gene is an ineffective genetic marker to be used to differentiate the closely related species of bacteria from similar genus.


2016 ◽  
Vol 27 (3) ◽  
pp. 318-324 ◽  
Author(s):  
Letícia M. M. Nóbrega ◽  
Francisco Montagner ◽  
Adriana C. Ribeiro ◽  
Márcia A. P. Mayer ◽  
Brenda P. F. A. Gomes

Abstract The objective of this study was to investigate the bacterial composition present in root canals of teeth associated with acute apical abscess by molecular identification (16S rRNA) of cultivable bacteria. Two hundred and twenty strains isolated by culture from 20 root canals were subjected to DNA extraction and amplification of the 16S rRNA gene (PCR), followed by sequencing. The resulting nucleotide sequences were compared to the GenBank database from the National Center of Biotechnology Information through BLAST. Strains not identified by sequencing were submitted to clonal analysis. The association of microbiological findings with clinical features and the association between microbial species were also investigated. Fifty-nine different cultivable bacteria were identified by 16S rRNA gene sequencing, belonging to 6 phyla, with an average number of 6 species per root canal. Molecular approaches allowed identification of 99% of isolates. The most frequently identified bacteria were Prevotella spp., Pseudoramibacter alactolyticus, Parvimonas micra, Dialister invisus, Filifactor alocis, and Peptostreptococcus stomatis. Positive association was found between Prevotella buccae and Pseudoramibacter alactolyticus and between Parvimonas micra and Prevotella nigrescens (both p<0.05). It was concluded that the microbiota of infected root canals associated with acute apical abscess is diverse and heterogeneous, composed mainly of anaerobic Gram-negative bacteria, with the great majority belonging to the phyla Firmicutes and Bacteroidetes.


2006 ◽  
Vol 56 (12) ◽  
pp. 2771-2776 ◽  
Author(s):  
K. Bouchek-Mechiche ◽  
L. Gardan ◽  
D. Andrivon ◽  
P. Normand

Three strains of Streptomyces reticuliscabiei and two strains of Streptomyces turgidiscabies were analysed, together with reference and type strains of other Streptomyces species, for phenotypic traits, DNA–DNA relatedness, comparison of 16S rRNA gene sequences and presence of necrotic protein gene (nec1) homologues in order to clarify their phylogenetic relationships. A numerical analysis of phenotypic characteristics showed that S. reticuliscabiei and S. turgidiscabies belong to the same cluster and share almost all morphological and biochemical traits that are important in the identification of Streptomyces species. DNA–DNA hybridization and phylogenetic comparisons of 16S rRNA gene sequences confirmed that the two species are genomically closely related. In contrast, pathological data showed that S. turgidiscabies and S. reticuliscabiei cause two distinct diseases. Gene homologues of nec1 were detected in S. turgidiscabies and other common scab species (Streptomyces scabiei, Streptomyces europaeiscabiei and Streptomyces stelliscabiei), but not in S. reticuliscabiei. To avoid confusion between agents causing separate diseases, it is proposed that the existing distinct species names are retained: S. turgidiscabies involved in common scab and S. reticuliscabiei involved in netted scab.


2015 ◽  
Vol 41 (1) ◽  
pp. 51-58
Author(s):  
Mohammad Shamimul Alam ◽  
Hawa Jahan ◽  
Rowshan Ara Begum ◽  
Reza M Shahjahan

Heteropneustesfossilis, Clariasbatrachus and C. gariepinus are three major catfishes ofecological and economic importance. Identification of these fish species becomes aproblem when the usual external morphological features of the fish are lost or removed,such as in canned fish. Also, newly hatched fish larva is often difficult to identify. PCRsequencingprovides accurate alternative means of identification of individuals at specieslevel. So, 16S rRNA genes of three locally collected catfishes were sequenced after PCRamplification and compared with the same gene sequences available from othergeographical regions. Multiple sequence alignment of the 16S rRNA gene fragments ofthe catfish species has revealed polymorphic sites which can be used to differentiate thesethree species from one another and will provide valuable insight in choosing appropriaterestriction enzymes for PCR-RFLP based identification in future. Asiat. Soc. Bangladesh, Sci. 41(1): 51-58, June 2015


2020 ◽  
Vol 139 ◽  
pp. 161-174
Author(s):  
R Palmer ◽  
GTA Fleming ◽  
S Glaeser ◽  
T Semmler ◽  
A Flamm ◽  
...  

During 1992 and 1993, a bacterial disease occurred in a seawater Atlantic salmon Salmo salar farm, causing serious mortalities. The causative agent was subsequently named as Oceanivirga salmonicida, a member of the Leptotrichiaceae. Searches of 16S rRNA gene sequence databases have shown sequence similarities between O. salmonicida and uncultured bacterial clones from the digestive tracts of marine mammals. In the current study, oral samples were taken from stranded dolphins (common dolphin Delphinus delphis, striped dolphin Stenella coeruleoalba) and healthy harbour seals Phoca vitulina. A bacterium with growth characteristics consistent with O. salmonicida was isolated from a common dolphin. The isolate was confirmed as O. salmonicida, by comparisons to the type strain, using 16S rRNA gene, gyrB, groEL, and recA sequence analyses, average nucleotide identity analysis, and MALDI-TOF mass spectrometry. Metagenomic analysis indicated that the genus Oceanivirga represented a significant component of the oral bacterial microbiomes of the dolphins and seals. However, sequences consistent with O. salmonicida were only found in the dolphin samples. Analyses of marine mammal microbiome studies in the NCBI databases showed sequences consistent with O. salmonicida from the common dolphin, striped dolphin, bottlenose dolphin Tursiops truncatus, humpback whale Megaptera novaeangliae, and harbour seal. Sequences from marine environmental studies in the NCBI databases showed no sequences consistent with O. salmonicida. The findings suggest that several species of marine mammals are natural hosts of O. salmonicida.


2020 ◽  
Author(s):  
CC Kim ◽  
WJ Kelly ◽  
ML Patchett ◽  
GW Tannock ◽  
Z Jordens ◽  
...  

© 2017 IUMS. A novel anaerobic pectinolytic bacterium (strain 14T) was isolated from human faeces. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain 14T belonged to the family Ruminococcaceae, but was located separately from known clostridial clusters within the taxon. The closest cultured relative of strain 14T was Acetivibrio cellulolyticus (89.7% sequence similarity). Strain 14T shared ~99% sequence similarity with cloned 16S rRNA gene sequences from uncultured bacteria derived from the human gut. Cells were Gram-stain-positive, non-motile cocci approximately 0.6μm in diameter. Strain 14T fermented pectins from citrus peel, apple, and kiwifruit as well as carbohydrates that are constituents of pectins and hemicellulose, such as galacturonic acid, xylose, and arabinose. TEM images of strain 14T, cultured in association with plant tissues, suggested extracellular fibrolytic activity associated with the bacterial cells, forming zones of degradation in the pectin-rich regions of middle lamella. Phylogenetic and phenotypic analysis supported the differentiation of strain 14T as a novel genus in the family Ruminococcaceae. The name Monoglobus pectinilyticus gen. nov., sp. nov. is proposed; the type strain is 14T (JCM 31914T=DSM 104782T).


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