38 research outputs found
PCR: A Powerful Method in Food Safety Field
In this chapter, application of the polymerase chain reaction (PCR) technique in food safety, considering all the branches of this concept, is presented. The area of interest contains important analysis for both human health and the identification of food adulteration. PCR techniques used for detection of genetically modified organisms (GMO) in different matrices, identification of different animal species in meat and dairy products, as well as the detection of food infection with food-borne pathogens and toxicogenic fungi are described. The working methods and result analysis are exemplified, starting with DNA isolation adjusted to different matrices, detection of target genes, and validation for all of these methods. Techniques of simplex PCR, primer multiplexing, primer design, validation of the laboratory methods, optimization of the PCR results, and result interpretation through the analysis of the electrophoresis gels and sequencing data are studied. At the same time, the obtained results, the obstacles encountered, and how they were overcome could be an example for specific analysis developed with less resources and also for adapting the existent validated methods to the new laboratory conditions. The practical applicability and the consumer’s demands are of great importance and always must be considered in developing and validating those methods
Plants Root Interference Area, A Benefit To The Microbial Community
Part of byproducts synthesized by plants through photosynthesis reach the ground, where create selective microenvironments for micro-flora and associations of plant - micro-organisms, which are a benefit for plant growth Setting the interference effect of the root interference area of vines and herbaceous plants and of radicular exudates from vine rhizosphere on microbial community and estimating microbial population present on the vine leaves. The biological material was represented by leaves (Fa, Fb), and soil rhizosphere (Ra, Rb) of two varieties of vines (Tamaioasa Romanian white and black / TA, TN), and from the vine roots interference area with other herbaceous plants (Ma, Mb). The soil has never been chemically treated. The microbiological study of biological samples was performed by classical and molecular methods. Overall, bacteria had a significant presence in soil samples taken from the root interference zone (Ma, Mb). Actinomycetes quantitatively dominated the root interference area of herbaceous plant with variety TA. The range of actinomycetes species and leaves microflora was reduced. In this study we have shown that significant growth of microorganisms occurs in the interference area of vine with other herbal plants as a result of the cumulative effect of radicular exudates
Latest Implications of Next-Gen Sequencing in Diagnosis of Acute and Chronic Myeloid Leukemia
The spectacular progress which was present in the past few years in the field of genome sequencing, together with the appearance on the market of some high performance devices in this field, the reduction of the costs regarding the analysis of the samples and the standardization of some protocols, has led to the establishment and introduction of the new generation of sequencing techniques in clinical diagnostic labs. An important role is played by the implementation of this technique in the oncology clinics. In this context, we found it appropriate to discuss in this chapter about the role of next-gen sequencing in determining the genetic probabilities of occurrence of oncological pathologies in the healthy population, the screening of these diseases at the population level, the diagnosis and classification of this pathology, the establishment of the therapeutic conduct using the technique, as well as the progression of the disease. In this chapter, we intend to discuss in particular the involvement of this technology in hemato-oncological diseases
EVALUATION OF THE GENETIC DIVERSITY OF ALLIUM ASCALONICUM LANDRACES BASED ON MOLECULAR MARKERS
The aim of the research was to identify Allium ascalonicum land races with a good yield due to their morphological traits, with good adaptation capacity, with different genetic background, as a first step in identification of a suitable source for the production of secondary metabolites. Therefore 16 shallot landraces collected from different areas of Timis county were evaluated from phenotypic and molecular point of view. Thus the height, diameter, weight and bulb shape index were determined. For genetic fingerprint 8 ISSR (Inter Simple Sequence Repeats) markers were used. The extracted DNA was amplified with the specific primers, the fragments were separated by agarose gel electrophoresis and analyzed with the VisionWorks®LS, (UVP, England) software. 178 amplified fragments were registered, with an average of 22.25/primer, of which 174 were polymorphic (97.75% polymorphism). The matrix of similarity and the dendrogram were established based on UPGMA (Unweighted Pair Group Method with Arithmetic Mean) analysis. A considerable genetic diversity between landraces with different ecologic origin was observed, indicating that they have different genetic mechanisms for the yield traits and adaptation to the specific environmental conditions of the area. All the obtained results allowed the identification of local land races with a high production capacity which had different genetic background (Dolat 126a, Sanmartinu S. and Rudna 101.) Therefore the posibility to recognize genotypes with distinct secondary metabolites content it was increased
Study on the effect of Allium Ursinum on soil bacteria evolution
Romania is included among European countries where Allium ursinum species is present. This species has
aroused the interest of the research team, because of the many positive aspects it shows, starting from the medical
field to the food sector. One of the objectives we have set and managed to capture in this paper refers to soil
microorganisms, the environment from which the plant takes the water and nutrients and whose fertility is
provided by microbial processes.
The biological material was represented by soil and Allium ursinum plants corresponding to each soil sample.
Source area of soil and garlic plant is the west part of Romania. Bacterial population was isolated from screened
soil samples (without plant debris) but also unscreened (plant residues were not removed), on culture media: soil
extract with added nutritive gelose.
Bacterial population abundance studies were performed after 24 and 48 hours of incubation, at the optimum
temperature for mesophilic microorganisms.
Although there were no differences in the nutrient substrate used for the study of culture "in vitro", the results
highlight that in the first 24 hours of incubation the bacterial population clearly dominate in the screened soil
sample, compared with the unscreened sample. In the next 24 hours, the existing quantitative bacterial differences
between the two samples were significantly reduced
The variation of actinobacteria species from a vicia sativa cultivated soil microhabitat
Actinobacteria is a fairly complex group, intermediate between bacteria and filamentous fungi involved in
producing some infection, in the case of pathogenic strains and recycling of organic matter, as in the case of
nonpathogenic actinobacteria. Literature data have surprised many plant-microorganism interaction, on the one
hand making reference to the mineralization processes involving microorganisms by whom plants necessary
nutrients are released, and on the other hand underlines the influence of plants on the quantity and quality of
microbial population in root area as a result of exudates removed in the natural environment.
Actinobacteria from Frankia genus are counted among bacteria being able to fix nitrogen, and those from the
genus Streptomyces are major producers of antibiotics and numerous secondary metabolites. This paper presents
the study of the composition of Streptomyces genus actinobacteria community from a moderately gleyed
eutricambosoil, grown with vetch (Vicia sativa). The soil is located in the western part of Romania. Biological
material sampling was conducted in October, the depth of 0-20 cm. Isolation and studies of this bacterial group
were performed "in vitro", on Gause 1 culture media. Actinobacteria were collected from four areas (biotopes):
the plot uncultivated with Vicia sativa (control variant), the far rhizospheric area, the hairy root and root areas of vetch plant. Based on effectuated observations, it was noticed that soil microhabitats contain a variety of
actinobacteria and S. albosporeus, S. aureus, S. griseus, S.albus, S. nigrescens, S. lavenduleroseus, S. helvolus.
Numerically dominant species in tested soil samples are: S. griseus, S. albus and S. albosporeus