I. Simeonov 3-4
I. ENVIRONMENTAL BIOTECHNOLOGY
E. Metreveli, E. Kachlishvili, D. Denchev, V. Elisashvili 5-11
V. Govorukha, O. Radchenko, O. Tashyrev 12-23
Ts. Prokopov 24-32
N. Matvieieva, K. Drobot, L. Pasichnyk, N. Zhytkevych 33-39
N. Stankova, R. Nedkov 40-46
D. Avetisyan 47-56
IV. MICROORGANISMS AND ENVIRONMENT
D. Denchev, L. Kabaivanova 57-64
V. RENEWABLE ENERGY SOURCES
L. Stoyanov, G. Notton, V. Lazarov
Eka Metreveli, Eva Kachlishvili, Dencho Denchev, Vladimir Elisashvili
Abstract: Among four white-rot basidiomycetes
tested, monocultures of Irpex lacteus
coccineus accumulated the highest
endoglucanase (53.2 and 61.5 U ml-1),
FPA (3.9 and 5.1 U ml-1), and xylanase
(58.9 and 58.6 U ml-1)
activities in submerged fermentation of
crystalline cellulose. Co-cultivation of these two
fungi accompanied with their synergism in enzyme
production and provided the highest yields of
cellulase and xylanase. By contrast, mixed
cultivation of Trametes
versicolor with P. coccineus
310 appeared to be unfavourable for cellulases and
xylanase production. In co-cultivation of
Key words: basidiomycetes, co-cultivation, cellulase, xylanase, submerged fermentation, production optimization
THERMODYNAMIC PROGNOSIS OF MICROBIAL INTERACTION WITH IRON COMPOUNDS
Vira Govorukha, Olga Radchenko, Oleksandr Tashyrev
Abstract. Microbial redox-transformation of iron compounds is closely related to the environmental conditions defined by a set of physical and chemical factors, including the pH and Eh value. Thermodynamic calculations of all theoretically feasible ways of microbial interaction with iron compounds (mobilization/immobilization, oxidation/reduction) are presented. It was theoretically grounded that microorganisms were capable to perform a high activity in the biogeochemical cycles of carbon and iron. Obtained results can be used to prognose the transformation of iron compounds by microorganisms in natural and man-made ecosystems and create biotechnologies of microbial purification of water sources and wastewater from iron compounds.
Key words: microorganisms interaction with iron, thermodynamic prognosis, iron reduction, biogeochemical role of microorganisms, microbial biotechnologies.
Abstract. Stalks’ powder of Jerusalem artichoke (Helianthus tuberosus L.) was tested as an agricultural waste product for the removal of Cu (II) ions from aqueous solution. Batch experiments were carried out to evaluate the effects of pH, biosorbent dosage, initial metal concentration and contact time. The maximum removal efficiency of about 71 % was reached at pH 4.0 by using of 5 g/dm3 biosorbent for 120, 90 and 60 min contact time, at 10, 50 and 100 mg/dm3 initial Cu (II) concentration, respectively. Pseudo-first-order, pseudo-second-order, Elovich’s equation and intraparticle diffusion models were applied to describe the obtained kinetic data. The pseudo-second-order model provided the best fit for experimental data with coefficient of determination grater than 0.99. Freundlich and Langmuir isotherm models were used to describe metal adsorption. Equilibrium data agreed well with Freundlich isotherm with R2 = 0.968.
Keywords: biosorbent, heavy metals, copper ions, kinetics, isotherms.
N. Matvieieva, K. Drobot, L. Pasichnyk, N. Zhytkevych
Abstract. An efficient protocol of Ruta graveolens L. shoot regeneration has been developed. MS media supplemented with 3% sucrose, Kinetin, 6-Benzylaminopurine (BA) and α-Naphthylacetic acid (NAA) growth regulators were used to find out the regeneration ability of intermodal, root, petiole and leaf explants. Addition of BA in concentration 0.5 mg L-1 promoted regeneration from petioles, roots and internodes with 100% frequency. The high frequency of shoot regeneration was also observed when the explants were cultivated on the MS basal medium with BA (0.5-1.0 mg L-1) and NAA (0.05-0.5 mg L-1). Extracts of R. graveolens regenerated plants exhibited antibacterial activity against Bacillus subtilis ATCC 6633, Staphylococcus aureus B918, A. rhizogenes A4 bacteria to the same extent as the extracts of initial plants. The extracts were not active against Escherichia coli and phytopathogenic bacteria. The method developed is simple and effective. It can be used for multiplication of plant material for the purpose of biologically active substances production and promote native ecosystems protection.
Keywords: Ruta graveolens L, shoot regeneration, growth regulators, antimicrobial activity.
Nataliya Stankova, Roumen Nedkov
Abstract: The aim of
this study is to investigate the forest vegetation
dynamics before and after a fire that took place in the
summer of 2007 on the
Keywords: forest fire, post-fire recovery, remote sensing, NDVI, VCI, MODIS.
Abstract. Vegetation cover degradation and soil erosion lead to processes connected with alternation of landscape structure and statement of landscape components. Simultaneously, these processes are accompanied by changing of heat – moisture ratio in landscapes and continuously running drought processes. Variations in solar activity can be considered as one of the possible factors causing vegetation cover degradation, drought, and desertification. In the recent study, vegetation cover degradation is assessed using satellite images and the vegetation indices Normalized Difference Vegetation Index (NDVI), Vegetation Condition Index (VCI), and Normalized Multi-band Drought Index (NMDI). Vegetation condition is one of the main factors of Universal Soil Loss Equation (USLE) used as basis of soil erosion assessment. Parallel study of both processes in 2000, 2007, and 2014 allows tracing of their dynamics and deriving possible trend in their progress.
Key words: Vegetation
degradation, soil erosion, vegetation indices, USLE
Dencho Denchev, Lyudmila Kabaivanova
Abstract: Soil microflora, as a component of biogeocenoses is experiencing different impacts by pesticides. Acting on the individual microbial species they affect and modify the ecosystems as a whole. On the other hand, many microorganisms can perform transformation and mineralization of pesticides. The aim of the study is to establish the nature of the interaction and sustainability of the model yeast and actinomycete populations with insecticide λ-cyhalothrin in laboratory conditions, as well as their ability to mineralize it. It has been found that a concentration of 0, 02% insecticide enhances the efficiency of utilization of the carbon substrate by the yeast population and inhibited actinomycetes at all concentrations tested. The addition of an insecticide in the medium decreases the activity of amylolytic enzymes and increases that of superoxide dismutase. The yeast strain Hansenulla anomala var.Schneggii can use λ-cyhalothrin as a sole carbon source.
Keywords: pesticides, λ- cyhalothrin, yeast, actinomycetes, growth, enzyme activity
Ludmil Stoyanov, Gilles Notton, Vladimir Lazarov
In a hybrid
system, the solar and wind power productions are used
together increasing the system reliability. This work
shows how solar energy and wind energy can be
complementary (or not) using hourly values of wind speed
and solar irradiation collected in 13 sites located in
Keywords: hybrid systems; solar energy; wind energy; renewable energy sources