The presented research was aimed to determine the parameters of chlorophyll fluorescence (IChH) curve induction for Vicia sativa L. that were grown on radionuclide contaminated soils by using "Floratest" fluorometer. Plants were inoculated with 5 species of bacteria that might potentially block radionuclide uptake (Agrobacterium radiobacter IМВВ-7246, Azotobacter chroococcum UКМВ-6082, A. chroococcum UКМВ-6003, Bacillus megaterium UКМВ-5724, Rhizobium leguminosarum bv. viceae) and grown in sod-podzolic, сhernozem and peat-bog soils, contaminated with 137Cs (4000±340 Bq/kg). As a result of research, it was determined that the most stressful factors for vetch plants are combination of soil radionuclide and presence of Bacillus megaterium UКМ В-5724, as the number of inactive chlorophyll increased. In addition, the vetch plants significantly increased fixed level of fluorescence (Fst) under the influence of radioactive contamination in presence of Bacillus megaterium UKM B-5724, indicating inhibition of photosynthetic reactions. Other bacteria showed radioprotective properties in almost all types of soil.
Nanosized materials have shown a relevant potential for practical application in a broad number of research fields, in industrial production and in everyday life. However, these substances acquire new properties and therefore may be biologically very active. This raise questions their potential toxic effects on living organisms. In some cases the nanosized materials or nano-composites possess distinct positive properties in enhancing the adaptation of plants in unfavorable conditions and in decreasing the negative effect of some chemical substances. The information about the positive and negative effects of nano-materials as well as the data concerned to the innovative approaches used by authors for the rapid assessment of the total toxicity with the exploitation of bacteria, Daphnia and plants are given. In last case a special attention is paid to the control of natural bioluminescence and chemoluminescence of living medium of organisms, the energy of the seed germination and the efficiency of the photosynthetic apparatus in growing plants by the estimation of chlorophyll fluorescence by the special “Floratest” biosensor. Three specific clases of nano-materials are analysed: a) nano-particles ZnO, Ag2O, FeOx, TiO2 and others, b) colloidal suspension of the same compounds, and c) nanostructured layered clay materials (acid saponites and Nb-containing saponite clays). The next features are analyzed: the biocidal activity (for nanoparticles), the improvement of the nutrition of plants on calcareous soils (for colloidal structures), the activity and performances as heterogeneous catalysts (for Nb-containing saponites, as selective oxidation catalysts for toxic organosulfur compounds into non-noxious products). The chemical and physical characterization of the nanosized materials described here was studied by different spectrophotometric and microscopic techniques, including AFM and SEM.
It is presented the experimental results about the investigations of the efficiency of the structured nano-pourous silicon (sNPS) application as transducer in the immune biosensors designed for the control of retroviral bovine leucosis (RBL) and the determination of the level such mycotoxins as T2 and patulin among environmental objects. Today, there is an arsenal of the traditional immunological methods that allow for the biochemical diagnostics of the above diseases and control of toxins but they are deeply routine and can not provide the requirements of practice for express analysis, its low cost and simplicity. Early to provide practical demands we developed immune biosensors based on SPR, TIRE and thermistors. To find more simple variant of the assay we studied the efficiency sNPS as trasducer in immune biosensor. The registration of the specific signals was made by measuremets of level of chemiluminescence (ChL) or photocurrent. The sensitivity of biosensor for both variants of the specific signal registration at the determination of T2 and patulin was about 10-20 ng/ml. Sensitivity analysis of RBL by this immune biosensors exceeds traditionally used approaches including the ELISA-method too. The optimal serum dilution of blood at the screening leukemia should be no less than 1:100, or even 1:500. The immune biosensor may be applied too for express screening leucosis through analysis of milk. In this case the optimal serum dilution of milk should be about 1:20. The total time of analysis including all steps (immobilization of specific Ab or antigens on the transducer surface and measurements) was about 40 min and it may be a sharp decline if the above mentione sensitive elements will be immobilized preliminary measurements. It is concluded that the proposed type of transducer for immune biosensor is effective for analysis of mycotoxins in screening regime.
In last time gardens are often at the dangerous of viruses and bacteria infections. To preserve not only the coming
harvest, but, in generally, to provide stability and growing horticultures the development of new generation of the
analytical techniques for remote express screening vegetative state arrays and direct control of the appropriate infection
if appearance of its maybe expected on the basis of previous surveys are very actually and important. For continuous
monitoring we propose the application of the complex of the optical analytical devices as “Floratest” and “Plasmatest”
(both produced in Ukraine) which is able to control step by step general situation with vegetable state and verify
concrete situation with infection. General screening is accomplished on the control of the intensity of chlorophyll
induction (IChF), namely, registration of so called Kautsky curve which testifies about physiological mechanisms of
energy generation, accumulation and effective ways of its realization in cells. The measuring may be done by direct
way on the number of individual vegetables and remote screening of massive with transferring registered signal direct
in the laboratory. Next step of control connected with the application of the surface plasmon resonance (SPR) based
immune biosensor which is able to determine concrete bacteria (for example, Erwinia amilovora) with the limit
detection about 0.2 μg/ml, the overall time of the analysis within 30 min (5 min of the duration of one measurement).
The traditional ELISA-method showed the sensitivity to this pathogen about 0.5 μg/ml, overall time of the analysis
several hours and obligatory using additional expensive reagents.
The real manifestations of biowarfare were only during local military conflicts. In previous times the danger with this
factor forms through activation of terrorist organizations. To prevent non-desirable consequences and to preserve the
lives and health of people it is necessary to provide constant control by the application of complex of the new generation
of the instrumental devices based on the principles of biosensorics which allow rapid revealing step by step: total toxicity
of environmental objects, presence of appropriate groups and specific chemical substances among them. It is
demonstrated simple and rapid estimation of the total toxicity through the control of the intensity of chlorophyll
fluorescence (IChF) by the direct or remote ways by the device “Floratest” (Ukraine). There is possible on the basis of
IChF curve of growing plants from some territory during appropriate period to reveal appearance of toxic substances in
this area. Their presence in more local cases may be done by using bioluminescent bacteria (pure Ukrainian strains)
or/and controlling short term Daphnia living medium by developed portable chemiluminometer. For the revealing of
some groups of toxic elements it is recommended the cerium oxide ISFETs based enzymatic biosensors. The last and
devices based on SPR (“Plasmotest”, Ukraine), porous silicon (with the registration of biospecific interaction
macromolecules by luminescence or electro conductivity) and some nano-metal oxides were realized in immune
biosensors at the determination of content of number of mycotoxins, some microorganisms (Salmonella spp.) and
diagnostics of viral disease (retroviral leucosis). We present the main characteristics of the above mentioned devices and
give confirmation that all the analysis meets practice demands. Overall time of analysis is in range 10 min and it is very
simple and may be realized in field conditions.
The purpose of the present study was to determine the effectiveness of the chlorophyll fluorescence method induction for the estimation of the functional state of the photosynthetic activity of plants. The study was done using the "Floratest" prototype portable device. It was found that the representative plants in three ecological zones have a significant difference of indexes, what, through the changes of the chlorophyll fluorescence induction, reflects the processes of energy transformation at the early stages of photosynthesis. It was stated that value of Kpl plateau in the Kautsky curve can be used as a test for the early selection of the horse chestnut forms, resistant to the influence of the complex environmental factors. The results in bean leaves indicated that the fluorescent indices are sensitive to the effects of such stressors as acidification, salinity, dehydration.
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