Yellow pigmented, filamentous, Gram-negative bacteria belonging to genus Flavobacterium are commonly associated with infections in stressed fish. In this study, inter-species diversity of Flavobacterium was studied in apparently healthy freshwater farmed fishes. For this, ninety one yellow pigmented bacteria were isolated from skin and gill samples (n = 38) of three farmed fish species i.e. Lab...

30 milled rice samples were collected from retailers in four states of malaysia. these samples were evaluated for eurotium spp. contaminations by direct plating on malt extract salt agar (mesa). all eurotium were isolated and identified based on morphology and nucleotide sequences of internal transcribed spacer 1 (its1) and its2 of the rdna. four eurotium species (e. rubrum, e. amstelodami, e. ...

as a case study, the genotypic polymorphism of the iranian material of diploid triticum was screened based on internal transcribed spacer 2 (its2) of the ribosomal dna (rdna) using single strand conformation polymorphism (sscp) analysis. this is a simple and cost effective technique for genotyping and investigating the allelic polymorphism among plant populations. performing sscp analysis among...

Molecular approaches have revolutionized our ability to study the ecology and evolution of micro-organisms. Among the most widely used genetic markers for these studies are genes and spacers of the rDNA operon. However, the presence of intragenomic rDNA variation, especially among eukaryotes, can potentially confound estimates of microbial diversity. To test this hypothesis, bacterially cloned ...

Species of Cestrum (Linnaeus, 1753) have shown large diversity in the accumulation and distribution of repetitive DNA families, and B chromosomes have been described in seven species. Some types of repetitive DNA were identified in A and B chromosomes in species of this plant group, such as AT-rich SSR, 35S and 5S rDNA, C-Giemsa and C-CMA/DAPI bands and retrotransposons. To increase our underst...

The diversity and dynamics of the microbial communities during the manufacturing of Ragusano cheese, an artisanal cheese produced in Sicily (Italy), were investigated by a combination of classical and culture-independent approaches. The latter included PCR, reverse transcriptase-PCR (RT-PCR), and denaturing gradient gel electrophoresis (DGGE) of 16S rRNA genes (rDNA). Bacterial and Lactobacillu...

A case of skin alterations and mortalities associated with Yersinia ruckeri in two summer old common carp after over-wintering a hibernation pond is described the present work. The disease was characterised mainly by erosions around orbital area fish. bacterium cultivated on Columbia agar identified MALDI-TOF, biochemical characteristics sequencing 16s rDNA. Parasitological virological examinat...

Human colonic biota is a complex microbial ecosystem that serves as a host defense. Unlike most microbial ecosystems, its composition has been studied extensively by relatively efficient culture methods. We have compared an established culture-based method with direct amplification and partial sequencing of cloned 16S rRNA genes from a human fecal specimen. Nine cycles of PCR were also compared...

Group I introns were discovered inserted at the same position in the nuclear small-subunit ribosomal DNA (nuc-ssu-rDNA) in several species of homobasidiomycetes (mushroom-forming fungi). Based on conserved intron sequences, a pair of intron-specific primers was designed for PCR amplification and sequencing of intron-containing rDNA repeats. Using the intron-specific primers together with flanki...

Fast and reliable identification of microbial isolates is a fundamental goal of clinical microbiology. However, in the case of some fastidious gram-negative bacterial species, classical phenotype identification based on either metabolic, enzymatic, or serological methods is difficult, time-consuming, and/or inadequate. 16S or 23S ribosomal DNA (rDNA) bacterial sequencing will most often result ...