CONTENTS
Editor's
comment
H. Najdenski
3-4I. MAN AND BIOSPHERE
L. Dimitrova, V.
Kussovski,V.
Hubenov, L. Kabaivanova,P. Angelov, H.
Najdenski 5-13
II. FOREST
ECOLOGY AND BIOLOGY
Assessment of the resource potential of the invasive alien species Impatiens Glandulifera Royle
P. Glogov, S. Gudorova,M. Bozhilova, M. Georgieva 14-22
Differentiation between populations of Platanus orientalis L. in Bulgaria - comparative analysis based on neutral markers and quantitative traits
M. Georgieva 23-28
III.
ECOLOGICAL AND SUSTAINABLE AGRICULTURE
Ecological approach for control the main pests on peach
H. Kutinkova, D. Stefanova, N. Palagacheva, V. Dzhuvinov 38-46
Soil monitoring in the Republic of Bulgaria and connection with the European system
M. Mladenov, S. Yaneva 47-55
IV.
RENEWABLE AND ALTERNATIVE ENERGY SOURCES
AND BIOFUELS
Study of photovoltaic system with micro-inverter
Z. Zarkov, I. Bachev, V. Milenov, L. Stoyanov 56-65
Microbiological fuel cells. Biology of anode processes. Electron transfer mechanisms
R. Koleva, H. Yemendzhiev, V. Nenov 66-74
V. ENVIRONMENTAL BIOTECHNOLOGY
Two-phase anaerobic digestion of corn steep liquor
E. Chorukova, V. Hubenov, L. Kabaivanova,Y. Gocheva, I. Simeonov 75-84
In Memorian
85
MICROBIAL DEGRADATION OF CELLULOSE-CONTAINING WASTE IN EARTH’S CONDITIONS AND IN A LIFE SUPPORT SYSTEM FOR MANNED SPACE FLIGHTS. PART I -TYPES OF CELLULOSE SUBSTRATES AND APPROACHES FOR THEIR BIODEGRADATION IN EARTH’S CONDITIONS AND LONG-TERM MANNED SPACE FLIGHTS
Lyudmila Dimitrova,
Vesselin Kussovski, Venelin
Hubenov, Lyudmila Kabaivanova, Plamen Angelov, Hristo
Najdenski
Abstract: The environment and
especially the
outskirts of cities are constantly facing numerous
environmental challenges, one of
which is the growing pollution due to accumulation of
cellulose-containing
waste. The same is observed during the long-term manned space
flights: a
huge amount of cellulose
waste are
accumulated, the
utilization of which is a definitive scientific challenge. In
recent years, many scientists have deepened and expanded
their research on this
issue concerning life support systems in long-term
spaceflight, which still
remains unresolved. Many experiments are being conducted on
biodegradation
processes in the conditions of simulated microgravity
focused on their future
application for the effective waste utilization in the life
support system. The microgravity
conditions have been shown to lead to changes in bacterial
gene expression,
growth rate, reduced motility, increased virulence and
biofilm formation, etc.
Therefore, this review aims to throw light on the types of cellulose
substrates and the various
approaches for their biodegradation in Earth’s conditions
and long-term manned
space flights.
Plamen Glogov, Stela Gudorova, Mariam Bozhilova, Mira L. GeorgievaAbstract: Based on comparative data taken from similar researches it was made an analysis of the resource potential of Impatiens glandulifera populations in specific areas and the possibilities for realization of the products according to the needs of the Bulgarian market. The total area of Impatiens glandulifera populations in the studied area is approximately 5000 m2. The estimated biomass of the populations is 2,89 t and their gross calorific value is 47627,2 MJ. The annual seed production of the species’ population in the research area is approximately 621 kg air-dry mass. The annual production of pollen is about 6 kg dry matter, and the honey production is 137,8 kg. Opportunities for utilization of plant biomass in the studied area at this stage are limited, due to the prospect of a significant reduction in the size of its populations in the upcoming years due to the envisaged control measures related to the conservation of biodiversity in natural habitats. At this stage, there is insufficient investor interest, production conditions and resources to use the production of Impatiens glandulifera as a source of biofuels. Small-range producers at a local level, where it is advisable to establish mixed production with other species, could use the output of fodder and honey. The effect of the medicinal and nutritional properties of the plant in the conditions of the Bulgarian socio-cultural and business environment requires confirmation based on in-depth studies before taking actions related to their marketing.
Keywords: invasive alien species, special uses, biofuels, honey, environmental management.
DIFFERENTIATION BETWEEN THE POPULATIONS OF PLATANUS ORIENTALIS L. IN BULGARIA - COMPARATIVE ANALYSIS BASED ON NEUTRAL MARKERS AND QUANTITATIVE SIGNS
Mira L. Georgieva
Abstract: The purpose of this article is to perform a comparative analysis of data from the two main types of studies on genetic differentiation in natural populations of Platanus orientalis L. in Bulgaria based on neutral genetic markers and quantitative traits. The objects of study include nine natural populations, representing the full distribution of the species in our country. Population differentiation calculated on the basis of neutral markers (FST) was estimated at 0.077 (FST=0.077). For comparison, the differentiation calculated on the basis of quantitative adaptive traits was used, which is the ratio of the variation within the populations (0.0397) and the total phenotypic variation composed of the variation between the populations (0.18987) and the intrapopulation component. Thus, the differentiation based on quantitative characteristics has a value of 0.17 (QST = 0.17). Quantitative traits should not be underestimated in studies of genetic variability between populations, at the expense of neutral molecular genetic markers, such as isoenzymes and various DNA markers. The results of these analyzes are obtained much faster, while the study of quantitative traits requires different progeny tests and other experiments that take more time, but the information obtained from them is no less important because they are related in most cases with the adaptability of individuals and hence with conservation practice.
Keywords: oriental plane, genetic diversity, differentiation, quantitative traits, population.
Stela Gudorova, Plamen Glogov
Abstract: The purpose of
this study
is to make an inventory of the data from the studies on
phytocenoses with diagnostic participation of Fraxinus ornus L. in Europe and Bulgaria and to
present an
up-to-date syntaxonomic classification of this type of
communities for the
territory of the country.As a result of the study of the communities with the participation of flowering ash, 19 associations of 4 classes, 5 orders and 7 unions were established, of which the greatest diversity of these communities is observed in the class Quercetea pubescentis and in the type Xerophytic and mesoxerophytic, microthermal and mesothermal vegetation in the xerothermic oak belt and in the hilly plains.
Most of the communities form habitats of conservation importance, included in national and international legislative documents related to their protection. Over 50% of these habitats fall into the categories of "endangered" and "potentially endangered".
The presented classification will help in the future studies on the communities involving flowering ash, forecasting their dynamics in natural plantations and artificial stands and applying effective silvicultural systems to restore indigenous vegetation types.
Keywords: phytocenoses, derivative vegetation, shrubs, xerophytes, thermophilic oaks.
Hristina Kutinkova, Desislava Stefanova, Nedyalka Palagacheva, Vasiliy Dzhuvinov
Abstract: The trials were carried out in the years 2019-2020 in an isolated peach experimental orchard of 1 ha in the area of Fruit Growing Institute, Plovdiv.
The aim of this study was to test the effectiveness of the ecological method mating disruption for control of oriental fruit moth (Grapholita molesta Busck) and peach twig borer (Anarsia lineatella Zeller) as an alternative of chemical treatments, using Cidetrak® ÎFM/PTB - MESO™ è Cidetrak® ÎFM L-MESO™ - the dispensers of Trécé Inc., USA. Pherocon® L2 OFM – lures with 1 mg orfamone for orienal fruit moth and Pherocon® L2 PTB lures with 1 mg anemone for peach twig borer were used. In the period of this investigation, we tested Pherocon® OFM Combo A&B dual lures, a new product developed by Trécé Inc., USA for the orchards with mating disruption.
It was established, that the mixed dispensers CIDETRAK® OFM/PTB MESO™ are alternative means for control both pests - the oriental fruit moth and peach twig borer.
The dispensers Cidetrak® ÎFM L-MESO™ successfully controlled the oriental fruit moth - Grapholita molesta Busck
Keywords: oriental fruit moth, peach twig borer, mating disruption, pheromones.
SOIL MONITORING IN THE REPUBLIC OF BULGARIA AND CONNECTION WITH THE EUROPEAN SYSTEM
Metodi Mladenov, Spaska Yaneva
Abstract: In the present study the review of the system for ecological monitoring of soils in the Republic of Bulgaria and the monitoring schemes applied on its territory is performed. The three levels of the system are considered in detail, together with their personal schemes, regulating the points (polygons), the parameters and the periodicity of observation, on the basis of which it is evaluated and the conclusions obtained as a result of the applied analysis are presented. The methods and techniques for soil sampling and techniques for subsequent analysis are also presented. The connections of the Bulgarian system with the European soil monitoring system are also considered.
Keywords: monitoring system, large-scale monitoring, monitoring of processes with regional activities, monitoring of processes with local activities.
Zahari Zarkov, Ivan Bachev, Valentin Milenov, Ludmil Stoyanov
Abstract: The article presents a study and modelling of a photovoltaic (PV) system connected to the grid via micro-inverter. Models of PV cell (panel) and the individual elements of solar micro-inverter are developed. A complete model of the system has been created, which presents an opportunity to simulate the operation of the inverter together with a PV panel at different weather conditions. The software used for the modelling of the system is Matlab/Simulink. An experimental study of the system in laboratory conditions using a solar simulator was performed in the Laboratory of Renewable Energy Sources (Electrical aspects), Faculty of Electrical Engineering of the Technical University - Sofia that gives the possibility to study the processes in solar systems in laboratory conditions. Current and voltage waveforms at different values of solar radiation and temperature of the panels were obtained. Some experimental results are also presented that prove the full functionality of the created mathematical models.
Keywords: Photovoltaic system, isolated grid-connected inverter, micro-inverter, Flyback converter.
MICROBIOLOGICAL FUEL CELLS. BIOLOGY OF ANODE PROCESSES. ELECTRON TRANSFER MECHANISMS
Ralitsa
Koleva,
Hussein Yemendzhiev, Valentin Nenov
Abstract. Microbiological fuel cells (MFCs) are
bio-electrochemical reactors which
convert the chemical energy of organic matter into
electricity due to the
specific electrogenic activity of certain groups of
microorganisms. In the
past, this technology was considered mainly as a source of
alternative energy
but today it is believed that the main advantages of these
systems originate
from their alternative application as a tool for studying
various processes of
biological wastewater treatment. However, in order MFCs to
be applied as such,
we need to gather detailed knowledge of their working
mechanisms. In this
context the aim of this review is to disclose the biology of
anode processes in
MFCs and to provide more clarity regarding the mechanisms of
electron transfer
in the anodic
chamber.
TWO-PHASE ANAEROBIC DIGESTION OF CORN STEEP LIQUOR
Elena Chorukova, Venelin Hubenov, Lyudmila Kabaivanova, Yana Gocheva, Ivan Simeonov
Abstract. Experimental studies of two-phase anaerobic digestion of corn steep liquor in continuous automatic and semi-automatic modes of the cascade system with simultaneous operation of both monitoring and control systems were performed. Corn steep liquor - a waste product from the process of treatment corn grain for starch extraction - was used as a substrate in the process of anaerobic biodegradation with hydrogen and methane production. The daily yields of biohydrogen in bioreactor 1 of the cascade (with working volume of 10 dm3) are variable and in good operation are in the range of 0.7 to 1.0 l of biogas from 1 dm3 working volume of the bioreactor, and the optimal pH range is in the range of 5.0 - 5.5. The concentration of hydrogen in the biogas from the hydrogen bioreactor 1 when a good process is accomplished is in the range of 14 - 34.7%. The daily yields of biomethane in bioreactor 2 of the cascade (with working volume of 80 dm3) vary in the range from 0.4 to 0.85 l of biogas from 1 dm3 working volume of the bioreactor, and the concentration of methane in the biogas from bioreactor 2 is high and remains practically constant (in the range 65-69%). At a dilution rate of 0.4 day-1 and a organic loading rate of 20 g/l for bioreactor 1, respectively a dilution rate of 0.05 day-1 for bioreactor 2, the best results were obtained.
Keywords: two-phase anaerobic digestion, corn steep liquor, pilot biogas plant, computer control system.