scholarly journals Molecular characterization of nocardioform actinomycetes in activated sludge by 16S rRNA analysis

Microbiology ◽  
1995 ◽  
Vol 141 (2) ◽  
pp. 513-521 ◽  
Author(s):  
M. Schuppler ◽  
F. Mertens ◽  
G. Schon ◽  
U. B. Gobel
LWT ◽  
2021 ◽  
Vol 147 ◽  
pp. 111579
Author(s):  
Creciana M. Endres ◽  
Ícaro Maia S. Castro ◽  
Laura D. Trevisol ◽  
Juliana M. Severo ◽  
Michele B. Mann ◽  
...  

2017 ◽  
Vol 84 (3) ◽  
Author(s):  
Irene Cano ◽  
Ronny van Aerle ◽  
Stuart Ross ◽  
David W. Verner-Jeffreys ◽  
Richard K. Paley ◽  
...  

ABSTRACTOne of the fastest growing fisheries in the UK is the king scallop (Pecten maximusL.), also currently rated as the second most valuable fishery. Mass mortality events in scallops have been reported worldwide, often with the causative agent(s) remaining uncharacterized. In May 2013 and 2014, two mass mortality events affecting king scallops were recorded in the Lyme Bay marine protected area (MPA) in Southwest England. Histopathological examination showed gill epithelial tissues infected with intracellular microcolonies (IMCs) of bacteria resemblingRickettsia-like organisms (RLOs), often with bacteria released in vascular spaces. Large colonies were associated with cellular and tissue disruption of the gills. Ultrastructural examination confirmed the intracellular location of these organisms in affected epithelial cells. The 16S rRNA gene sequences of the putative IMCs obtained from infected king scallop gill samples, collected from both mortality events, were identical and had a 99.4% identity to 16S rRNA gene sequences obtained from “CandidatusEndonucleobacter bathymodioli” and 95% withEndozoicomonasspecies.In situhybridization assays using 16S rRNA gene probes confirmed the presence of the sequenced IMC gene in the gill tissues. Additional DNA sequences of the bacterium were obtained using high-throughput (Illumina) sequencing, and bioinformatic analysis identified over 1,000 genes with high similarity to protein sequences fromEndozoicomonasspp. (ranging from 77 to 87% identity). Specific PCR assays were developed and applied to screen for the presence of IMC 16S rRNA gene sequences in king scallop gill tissues collected at the Lyme Bay MPA during 2015 and 2016. There was 100% prevalence of the IMCs in these gill tissues, and the 16S rRNA gene sequences identified were identical to the sequence found during the previous mortality event.IMPORTANCEMolluscan mass mortalities associated with IMCs have been reported worldwide for many years; however, apart from histological and ultrastructural characterization, characterization of the etiological agents is limited. In the present work, we provide detailed molecular characterization of anEndozoicomonas-like organism (ELO) associated with an important commercial scallop species.


2020 ◽  
Vol 78 (7) ◽  
pp. 541-546 ◽  
Author(s):  
Akiko Oshiro ◽  
Takashi Zaitsu ◽  
Masayuki Ueno ◽  
Yoko Kawaguchi

2006 ◽  
Vol 8 (3) ◽  
pp. 405-415 ◽  
Author(s):  
Eva Spieck ◽  
Christine Hartwig ◽  
Iris McCormack ◽  
Frank Maixner ◽  
Michael Wagner ◽  
...  

2018 ◽  
Author(s):  
Ismail Marzuki ◽  
Alfian Noor ◽  
Nursiah La Nafie

Molecular characterization studies have been conducted 16S rRNA gene micro symbiont of sponge origin Melawai Beach, Balikpapan in East Kalimantan. Objective analysis of histo- morphological research, isolation-purification, molecular characterization of micro-symbiont genes in order to search symbiont bacteria that can live in extreme environments contaminated hydrocarbon waste. The research method that morphological identification, isolation-purification and molecular characterization of the 16S rRNA gene with Chain Reaction Polymerization method. The results of histo-morphological analysis concluded sponge samples with species of Callyspongia sp. Isolation and purification mikro symbionts of sponge obtained 2 (two) isolates. Characteristics of Isolates 1; spherical shape, colonize and creamy, while isolates 2; jagged shape, oval and white colonies. Molecular characterization of the 16S rRNA gene by PCR, Bacillus subtilis strain BAB-684 identification for isolates one is the number of nucleotide pairs reached 899 bp and the degree of similarity in GenBank reached 89% homologous, while the second is a Bacillus flexus strain PHCDB20 isolates the number reached 950 bp nucleotide pairs with the degree of similarity in GenBank reached 99% homologous


2020 ◽  
Vol 5 (01) ◽  
pp. 22-33
Author(s):  
Eka Oktaviani ◽  
Rejeki Siti Ferniah ◽  
Arina Tri Lunggani

Rejuvenation and conservation of mangrove ecosystems, especially the Teluk Awur mangrove ecosystem, Jepara Regency, can be done by using bacteria that are capable of supporting plant growth or called Plant Growth Promoting Rhizobacteria (PGPR). One of the mechanisms that support plant growth by the PGPR group is phosphate dissolving activity, because the phosphate in the soil is in the form of a compound that is difficult for plants to absorb. This study aims to determine the character of Rhizobacter isolates as a superior phosphate solvent in dissolving phosphates in-vitro from the Teluk Awur mangrove ecosystem, namely isolates coded EO-4. These isolates have similar microbiological and biochemical characters to the genus Enterobacter. Molecular characterization of isolates was carried out using the Polymerase Chain Reaction (PCR) method - 16S rRNA sequence analysis (comparing with 16S rRNA sequences in gene banks). The results showed that the phosphate-solubilizing rhizobacteria that were isolated had the same base pair percentage of 48% with Enterobacter pyrinus (access number NR_028875).


Author(s):  
M.K. Doley ◽  
S. Das ◽  
R.K. Sharma ◽  
P. Borah ◽  
D.K. Sarma ◽  
...  

Background: Riemerella anatipestifer (R. anatipestifer) is a gram negative, microaerophilic, non-motile, bipolar bacteria. High genetic diversity and molecular differentiation were reported among field isolates. Although the bacterium causes one of the most economically important duck diseases in the north-eastern region of India, little work has been done on isolation, identification and molecular characterization of the bacteria. Hence, the present investigation was undertaken with a view to characterize the R. anatipestifer isolates from ducks of Assam.Methods: Phenotypic and molecular identification of R. anatipestifer isolates from domesticated ducks of Assam, India were carried out during the period from February, 2019 to January 2020. A total of 624 samples (Ocular swab, throat swab, liver, spleen, kidney, brain, heart, lung) from ducks comprising of apparently healthy, ailing and dead ducks were collected from five districts of Assam, India were processed to isolate and identify the bacteria. The tentative identification of the bacteria was done based on phenotypic characteristics viz., colony morphology, growth characteristics and biochemical reactions. All the phenotypically positive isolates were further subjected to molecular identification based on PCR assay targeting 16S rRNA gene and ERIC sequence.Result: The bacteria could be isolated from different field samples. The highest percentage of the samples that yielded the bacteria are from brain (76%) followed by spleen (74%) of dead ducks and less number of ocular swab (33%) from apparently healthy ducks were found positive. Sequencing of the amplified product of the selected R. anatipestifer isolates targeting 16S rRNA gene revealed homology percentage of 96.5-100%. Further, sequences representing five geographical locations were submitted to NCBI gene bank. Phylogenetic studies of the isolates indicated that there is prevalence of at least two genetically different strains of R. anatipestifer in the study area. The study suggested that the R. anatipestifer infection is endemic in Assam causing varying rate of morbidity (39%) and mortality (53%) and molecular based confirmation is necessary besides phenotypic identification.


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