Ecological Engineering and Environment Protection

Abstract. In recent years it was observed a trend for increased interest in lactic acid bacteria (LAB), isolated from non-dairy environment due to their diverse metabolic profile and unique flavor-forming activities. Looking for new solutions to improve starter systems for healthy fermented foods and to expand opportunities for maximum utilization of biological potential of LAB, results in the idea of exploiting biodiversity of the unique natural bio-systems (medicinal plants). After large-scale screening of 300 microbial isolates (obtained from different parts of Geranium sanguineum L.) based on coagulation of milk, gas formation and non-specific odour and succeeding multiple transfer and growth in MRS and M17 selective media were isolated 169 single bacterial colonies. By differentiating tests were selected 62 Gram (+) and catalase (-) LAB. Of the representative lactic acid flora of G. sanguineum L. was studied acid-producing activity.

Keywords: Geranium sanguineum L., lactic acid bacteria, isolation, screening

Antibacterial activity of mature and green Allium cepa

Kirilov A., Doycheva A. and G. Satchanska

(PDF 841k)

Abstract: Antibacterial in vitro activity of white (bulb), red (bulb) and spring (bulb and leafs) onion towards the Gram-negative Escherichia coli 8752 and the Gram-positive Bacillus subtilis 8751 was investigated. Mature onion samples were purchased from a big supermarket while the green onion was organically grown. Experiments were performed via agar well diffusion method. Samples were separately homogenized with a blender until reaching fine paste. 0.1 mL of the test bacteria at concentration 1x10⁹ CFU/mL were inoculated on the nutrient agar. The onion paste (0.25 g) was loaded in aseptically perforated in the agar wells with a diameter 9 mm. The petries were cultivated at 37^oC for 24 hours and further the sterile zones around the wells were measured. Our results revealed that the white and red onion bulbs were active against Gram–positive bacteria showing 27 mm and 25 mm inhibition zone and displayed weak activity towards Gram-negative bacteria. Green onion bulbs and leafs did not inhibited the growth of B. subtilis and E. coli. The highest inhibition grade was registered for the white variety of Allium cepa.

Key words: antibacterial activity, medicinal plants, Allium cepa; mature onion, green onion

COBALT CHLORIDE TREATMENT AND IRON METABOLISM IN IMMATURE MICE

Y. Gluhcheva, E. Pavlova, V. Atanasov, I. Vladov

(PDF 847k)

Abstract. Although cobalt is an essential trace element, it is toxic in high concentrations. Long-term exposure to cobalt chloride (CoCl₂) significantly increases Co(II) ions in blood serum, spleen and liver of treated immature mice compared to controls and induces changes in the iron (Fe) content. Spleen and liver show different sensitivity to Co(II) administration but increase iron storage. The three experimental groups of immature mice – day 18-, 25- and 30, used in the experimental design, show different sensitivity to the metal. This suggests that the stage of development is also an important marker that should be considered.

Key words: cobalt chloride, iron metabolism, immature mice, liver, spleen

SPECTRALLY-BASED APPROACH TO EVALUATING CROP PERFORMANCE UNDER STRESS GROWING CONDITIONS

Rumiana Kancheva, Georgi Georgiev, Denitsa Borisova

(PDF 1161k)

Abstract. Recent developments in environmental studies are greatly related to ecological problems arising from anthropogenic impacts on the biosphere and especially on vegetation. The interrelated nature of many environmental issues imposes the necessity to conduct interdisciplinary research and implement different approaches, to integrate the acquired data and share information between different databases. Remote sensing provides advanced monitoring and alerting techniques, timely information extraction, modeling and forecasting possibilities used for solutions of important environmental problems we are confronted with. Such worldwide pressing concerns are natural resources management, ecosystem preservation and biodiversity conservation. Remote sensing technologies make use of land cover spectral features for detecting and assessing changes associated with environmental conditions. In this paper, we investigate and analyze the relationship between growth variables and spectral response of agricultural species under stress growing conditions (heavy metal pollution, nutrient deficiency and soil acidity). Multispectral data obtained from ground-based spectroradiometric measurements are examined in terms of the ability to serve as an indicator of crop performance.

Keywords: remote sensing, spectral characteristics, growth variables, stress detection, nutrient deficiency, heavy metals

CHLOROPHYLL ASSESSMENT AND STRESS DETECTION FROM VEGETATION OPTICAL PROPERTIES
Rumiana Kancheva, Denitsa Borisova, Georgi Georgiev

(PDF 1521k)

Abstract. Vegetation monitoring is one of the essential applications of remote sensing. Regarding agricultural lands, a primary goal is crop state assessment throughout the growing season. Remote sensing techniques make use of multispectral data to estimate plant biophysical and biochemical characteristics by implementing quantitative relationships between crop growth variables and spectral properties. Chlorophyll is a key biochemical component that is responsible for photosynthesis and is a physiological indicator of plant condition. Changes in plant pigment content can be used to assess the impact of environmental stresses. In this paper, we present results from ground-based spectrometry studies of the spectral behaviour of agricultural species in relation to varying chlorophyll. Multispectral data were analyzed to reveal the performance of different spectral indicators for chlorophyll estimation. Reflectance factors, vegetation indices, red edge shift, transmittance spectra, chromaticity features and fluorescence parameters were related to chlorophyll content and the statistical significance of plant spectral response to chlorophyll variations was examined. High correlations were observed and empirical relationships derived linking plant optical properties and chlorophyll content. These relationships were used for plant stress diagnosis in terms of chlorophyll synthesis inhibition.

Keywords: remote sensing, plant reflectance, vegetation indices, red edge, fluorescence, chlorophyll, stress detection.

AUTECOLOGY OF MICROORGANISMS OF COASTAL ECOSYSTEMS OF THE DEAD SEA

Victoria Romanovskaya, Galina Gladka, Oleksandr Tashyrev

(PDF 808k)

Abstract.. From coastal ecosystems of the Dead Sea (vertical steep gorge around of the Dead Sea, clay-salt plain and a black highly mineralized muds) Bacillus licheniformis, B.subtilis subsp. subtilis, Bacillus sp., Staphylococcus hominis strains have been isolated. All strains grew at 0-10 % of NaCl in medium, in a range of 20-50°С. Resistance to UV has been revealed in all the investigated bacteria. Lethal doses of UV (LD₉₀ and LD_99,99) for spore-forming strains were 100-150 and 1100-1500 J/m², respectively; for strain 6t1 (does not form spores) - 50 and 370 J/m². Some strains of genus Bacillus had strong antagonistic effect on conditionally pathogenic test cultures Staphylococcus аureus and Candida аlbicans. Among the isolates discovered strains which showed lipase or amylase or elastase activity. These properties of the bacteria may be used in various biotechnology.

Keywords: extremophilic bacteria, Dead Sea, halo- and thermo-tolerance, resistance to UV, antagonism.

Application of NAnodiamonds in Wastewater Treatment Technologies

Ivaylo Yotinov, Mihaela Belouhova, Irina Schneider, Yana Topalova

(PDF 1088k)

Abstract: Nanotechnology is a rapidly developing scientific area and nanoproducts continually increase their use. Thus, they become the subject of more research. Nanodiamonds (NDs) are a class of nanomaterials which attracted worldwide attention with high biocompatibility, non-toxicity and many opportunities for surface chemical interactions. Furthermore, the surface functional groups on NDs can be easily adapted so that they exhibit valuable chemical, physical and biological properties. This article discusses the main characteristics of the NDs, with their potential use in stimulation, indication and monitoring of the wastewater treatment and biodegradation processes.

The effect of diamond nanoparticles on the transformation of the azo-dye amaranth during the treatment process, modeled in sandy sequencing batch biofilter has been discussed as case study in this paper. In the described examples key parameters were evaluated: residual concentration of amaranth, enzymе activities, effectiveness of amaranth decolorization, chemical oxygen demand and total organic carbon. The data showed the positive role of the diamond nanoparticles as a modulator. These results discover perspectives for further research and applications of NDs in the stimulating of biodegradation processes in wastewater treatment technologies.

Key words: amaranth, biological wastewater treatment, enzyme activity, nanodiamonds, waters

BLUE TECHNOLOGY TOWARDS SUSTAINABLE URBAN AND COASTAL DEVELOPMENT

Nicholas Kathijotes

(PDF 916k)

Abstract. The aim of Blue Economy models are to shift society from scarcity to abundance –based on what we have, and to start tackling issues that cause environmental and related problems through new and novel ways. Some major factors that cause ecological alterations to coastal and surface waters and contribute to nutrient inputs include, in no special order, municipal wastewater and storm water discharges; combined sewer overflows; other urban runoff; agricultural runoff; aquacultures, and various others. The issue of nutrient input due to aquaculture, being a serious input source in developing countries is emphasized together with actual measurements and control techniques applied in EU. Other key issues in coastal and aquaculture environments including Coastal Tourism, Marine Renewable Energy, Blue Biotechnology and Spatial Planning are presented within the scope of blue economy principle and thus suggesting novel actual management techniques.

Keywords: Blue economy, nutrients, fisheries, sustainability, tourism, biotechnology.

THE COMPARISON OF WHITE-ROT BASIDIOMYCETES LIGNOCELLULOLYTIC POTENTIAL IN WHEAT STRAW SOLID-STATE FERMENTATION

Violeta Berikashvili, Tina Jokharidze, Eva Kachlishvili, Tamar Khardziani, Dencho Denchev, Vladimir Elisashvili

(PDF 795k)

Abstract: In the present study, a screening of 12 white-rot basidiomycetes has been carried out to evaluate their potential to deconstruct cellulose and lignin in solid-state fermentation (SSF) of wheat straw. The degradation patterns of cellulose and lignin in wheat straw by tested fungi differed significantly. Among them, Cerrena unicolor, Trametes hirsutus 68, and Tsalka 5 were able to remove lignin slightly preferentially and faster than cellulose during 12 days of fermentation and are appropriate candidates for biological pretreatment of wheat straw. Evaluation of the tested fungi cellulases and ligninases activities revealed that the cellulose and lignin degradation not always directly correlates with the production of enzymes.

Key words: white-rot basidiomycetes, wheat straw, cellulose and lignin degradation, cellulase, laccase, manganese peroxidase