2019, Vol. 17, No. 6

Selle kollektsiooni püsiv URIhttp://hdl.handle.net/10492/5519

Sirvi

Nüüd näidatakse 1 - 20 31

Evaluation of retention stresses of prestressing bars of a concrete ribbed panel from agricultural building after 20 years of service
(2019) Kiviste, Mihkel; Lille, Harri; Linnus, Lauri; Halgma, Riho; Estonian University of Life Sciences. Institute of Forestry and Rural Engineering. Chair of Rural Building and Water Management
In Estonian agricultural buildings there exist a lot of precast concrete load-bearing structures, which were manufactured in the 1970s and 80s. By now, some of these are rather near for reaching their designed service life. 20 years old prestressed concrete ribbed ceiling panels (type PNS-12) with the dimensions of 6 m (length) by 1.5 m (width) from an existing agricultural building (pigsty) are the subject of current study. The objective of current study was to evaluate the retention stress of prestressing bars (PSBs) of a ribbed panel PNS-12. In other words the purpose was to find out how much of the factory-issued initial prestress was left at the PSBs after 20 years of service. As a novel application in civil engineering strain gauges were applied in the evaluation of retention stress of PSBs in current study. The active strain gauges were glued to the opposite sides of PSBs at the middle-span of the ribbed panel, dummy gauges were glued to the unloaded steel slab. Strain gauges were connected to the half-bridge and measured with strain indicator and recorded. Retention stresses were calculated using the Hooke’s law through the measured strains and elastic modulus of steel. Elastic modulus of PSBs was also measured using the universal testing machine Instron 3369 and software Bluehill 2, based on two standards. The results demonstrated about 20.8% and 10.0% of retention stress of PSBs, respectively. The possible errors created by different aspects in experiment are also discussed.
Determination of activation energy of the pellets and sawdust using thermal analysis
(2019) Kunecová, D.; Hlaváč, P.
The aim of this study is to describe the thermophysical properties of pellets and sawdust. Samples were chosen with regard to sustainability and environmental friendliness of materials. The main object of this paper was the investigation of thermal degradation of selected samples. Industrial pellets from Slovakia and sawdust from household source were compared. Materials suitable for pyrolysis are organic materials that degrade at increased temperature. Cellulose, hemicellulose and lignin are main components of biomass (wood) in varying proportions. Thermal processes were carried out from 25 °C to 850 °C using inert nitrogen atmosphere. Heating rate was linear from 5 °C min-1, 10 °C min-1 to 20 °C min-1. Mass decrease to 150 °C corresponds to release of water and other lighter unbound hydrocarbons. Samples lose 6–8% of their mass due to the temperature. At main decrease the mass loss was between 62% and 69%. In some cases this decrease is in two drops that end at the temperature around 500 °C. Pyrolysis can be considered to consist of independent parallel reactions. In order to make theoretical groundwork for biomass pyrolysis available, activation energies were calculated with the help of two kinetic models (Kissinger-Akahira-Sunose and Flynn-Wall-Ozawa model). The residuals from pyrolysed samples are determined and temperature dependent profiles of the materials were obtained.
Technology development of obtaining essential fatty acids from hydrobionts hydrolyzates
(2019) Kuprina, E.; Filipov, V.; Malova, A.; Abramzon, V.; Lepeshkin, A.; Chikisheva, M.
ɷ-3, 6-fatty acids from hydrobiontsare a minor component in the nutrition of European countries population. This causes a number of diseases, such as cardiovascular ones, cancer etc. There is a task of concentrating these acids in oil due to the fact that to meet their daily needs it is problematic to use large quantities of fish oil-from 15 to 20 g. Particularly rich in ɷ-3, 6-acids are wastes from the cutting of hydrobionts, containing muscle tissue and skin. Protein hydrolysates were obtained from rainbow trout (Oncorhynchusmykiss) and Atlantic herring (Clupeaharengus) wastes by the electrochemical method using electrolyzers of the original design which are allowed to be used in food industry. A technological scheme of separating of lipids from protein hydrolyzates has been developed and experimental batches of oil samples have been developed. To concentrate the fatty acids the cryoconcentration method was used. The phase transitions of the obtained lipids were studied after their cryoconcentration in the temperature range from + 15 °C to minus 40 °C in the environment of calcium chloride using a low-temperature refrigeration unit. To analyze phase transitions the plant was used, which is a container with a solution of calcium chloride cooled by a low-temperature refrigeration machine. The properties of 5 fractions of lipids formed at the time of lipid phase transitions have been identified and studied (the fractional composition, acid, iodine numbers, the content of polyunsaturated fatty acids (PUFAs), vitamin D3 and A). It was established that as cryoconcentration increases the concentration of PUFAs, reaching values close to 90%, which allows the resulting product to be attributed to biologically active food additives (BAA). By calculation, it was shown that to create functional food products on fish base from fish of the Gadidae family it is enough to inject 4 grams of BAA to 100 grams of the product. Organoleptic properties of food products from low-fat fish species were improved.
Typology of small producers in transition to agroecological production
(2019) Escobar, N.; Romero, N.J.; Jaramillo, C.I.
Agroecology is now emerging as the fundamental science to guide the conversion of conventional production systems to more diversified and self-sufficient systems. The agroecological transition is defined as the gradual change that farmers undergo to adapt and move from more conventional towards agroecological farming principles, encompassing technological, societal, institutional and organisational changes in the food system. To analyze a transition process, it is initially necessary to understand how agroecosystems work (their structure and processes), and the different ways human beings intervene an ecosystem in order to transform it for productive purposes.Farm systems typology and classification techniques are used to guide strategic lines of research, sectorial policies, and promote sustainable development in response to farmer’s needs. Determining multidimensional classification methods in agricultural systems is necessary, considering both the variables inherent to the production system and those of an external nature that indirectly impact the development and long-term sustainability of production systems. One of the purposes of this research was to characterize agricultural production based on sustainability systems and environmental, social, and economic indicators. The study was carried out based on data collected from 71 farm surveys, considering the social, economic, environmental, and technological dimensions. Multiple correspondence and cluster analysis were done. Three types of production systems were obtained: Group I, organic producers in transition; Group II, conventional producers in transition to organic production; and Group III, conventional producers interested in organic production. Producers need to focus on processes that allow them to improve their skills to develop human talent and social capital in terms of integration, collaborative work, trust, political and cultural capital, so that they can make progress easily and start implementing agroecological, infrastructure, and natural resources management practices, while improving their living standards. The information yielded by a typology process allows for us to know the current state of agricultural production systems based on the implementation of agroecological practices; thus facilitating the preparation and implementation of participatory plans and/or integrative proposals that promote agrofood sustainability.
Investigation of fly larvae Lucilia Caesar application in pet feed composition
(2019) Nadtochii, L.; Baranenko, D.; Melchakov, R.; Muradova, M.; Istomin, A.; Istomin, A.
The biomass of insect larvae is world-widely used as a valuable raw material for the pharmaceutical, microbiological, cosmetic industry and feeding production, also in the food industry. There is certain complex technology for processing biomass of insect larvae, which affords to isolate many physiologically active substances - chitin, antimicrobial peptides, fatty acids mixture, organic forms of mineral substances, hormones, etc. The company New Biotechnology (Lipetsk, Russia) has developed a technical process for producing of the protein-lipid preparation (commercial name is Zooprotein) based on the fly larvae of the species Lucilia Caesar. The utilization of food waste as a substrate, unpretentiousness to cultivating environment and high protein content are capable of considering insects of the species Lucilia Caesar as a promising object of cultivation and a reliable, cheap, replenishable source of nutrients for resource-saving process of the feed production. On the bases of ITMO University, an investigation is being conducted on the qualitative composition of the Zooprotein and the possibility of pet feed application. Cats are the most demanding animals to the quantitative and qualitative composition of protein fractions of feed. In present research an evidence-based calculation of the balance of the Zooprotein composition is presented as a feed component for cats during growth. Accordingly, the unique chemical composition of the development product based on fly larvae Lucilia Caesar makes possible to maintain that it is a promising functional ingredient in feeding rations for various animal species.
Biological effect of hydroxycitric acid within a Garcinia Cambogia extract on the nutrient metabolism
(2019) Martirosyan, V.V.; Baluyan, Kh.A.; Kostyuchenko, M.N.; Malkina, V.D.; Zhirkova, E.V.; Marshalkin, M.F.
Among plant supplements, which once included in a food regimen, induce a favorable evolution in persons seeking to lose some weight, Garcinia cambogia fruit containing hydroxycitric acid deserves close attention. The aim of this study consisted in the investigation of a biological effect of hydroxycitric acid within a Garcinia cambogia extract on the nutrient metabolism. The study involved the use of a Garcinia cambogia extract comprising hyroxycitric acid in the amount of 60.23%. In view of simulating the conditions of digestion, model dietary media consisting of extrusion products added with a Garcinia cambogia extract and enzymes were developed. The simulation of digestion processes in experimental model media has shown the decrease of glucose formation. Possibly hydroxycitric acid inactivates the activity of amylases, what results in the decline in the content of free monosaccharides and in the reduction of synthesis of glycerol as a fat component with the effect of an inhibited triglyceride formation. The addition of an extrusion product comprising the Garcinia cambogia extract to the diet of laboratory animals (rats) after 28 days of the experiment resulted in a reliable reduction of blood total cholesterol and triglycerides by 13% and 28%, respectively, and also in the decrease of body weight of animals by 5.8%. The investigation confirms the data available in the literature on the properties of hydroxycitric acid within a Garcinia cambogia extract, which influences the nutrient metabolism, thereby allows using brindleberry processing products for the correction of body weight.
Some rheological properties of new and used mineral lubricant and biolubricant for tractors
(2019) Csillag, J.; Petrović, A.; Vozárová, V.; Kosiba, J.; Majdan, R.
It is important to know physical characteristics of lubricating oils to ensure the highest reliability for operation of device. The use of ecological lubricants depends on their characteristics; the most important are density and viscosity, protection against wear and tear, corrosion resistance etc. The objective of this work was to find changes of the rheological properties of the synthetic oil and bio lubricant. We compared two different oils in our measurements. One sample was synthetic oil and the other was mineral oil (bio lubricant). Both oils are universal oils for tractors. Further, comparison of new and used sample after million cycles was performed. The density and the dynamic viscosity show strong exponentially decreasing dependence. With the increasing temperature, values of the both properties, decreased. It can be also observed that used samples have lower viscosity and density. The results presented in this article can be important when putting ecological lubricants into operation.
Comparison of a 1 t and a 55 t container when storing spelt grain in mild climate of the Czech Republic
(2019) Bradna, J.; Šimon, J.; Hájek, D.; Vejchar, D.; Polišenská, I.; Sedláčková, I.
Maintaining a suitable microclimate inside the storage space is the most significant factor in maintaining good quality of stored grain for small farmers. This article is aimed at evaluating the influence of outdoor climatic conditions on the storage conditions, specifically the temperature of stored grain in two storage containers. One structure was a 4 × 6 m cylindrical container (55 t capacity) with a steel wire mesh wall lined with a textile shell. Spelt grain (Triticum spelta) was also stored simultaneously at the same location in a fabric intermediate bulk container (FIBC) bag with maximum capacity of 1 t. Neither structure was mechanically aerated. Grain moisture and temperature were monitored during the spring and start of the summer period of the year 2017 because of the biggest differences between the night and day temperatures. For monitoring of the grain microbiological changes samples were taken for laboratory tests during the whole experiment. Grain quality parameters measured during storage included the bulk density, crude protein, falling number, germination, gluten content, sedimentation index and contamination by mycotoxins. Monitored outdoor environment parameters were temperature, dew point and relative humidity. Results showed a strong dependence of the stored material temperature on the outside temperature in the case of FIBC bags (coefficient of determination R 2 = 0.927), whereas the dependence was weaker in the larger structure (R 2 = 0.625). Mycotoxins monitored during the period were below the detection limit in both cases.
Vegetative growth response of beets and lettuce to stored human urine
(2019) Chávez, J.A.; Alcántara-Flores, J.L.; Almiray-Pinzón, R.C.; Díaz-Cabrera, E.; Pérez-Avilés, R.; Patiño-Iglesias, M.E.; Mora-Ramírez, M.A.
In this work, we present the experimental results of the effect of stored human urine (SHU) on the growth of beets (Beta vulgaris L) and lettuce (Lactuca sativaL). We apply different amounts of SHU according to the recommended dose of nitrogen, considering soil from farmland and vermiculite as substrates. The last allows us to determine with high precision the isolated effect of SHU over the vegetative development of beet plants, without considering other nutrients present in common soils. Experimental results demonstrate that the application of SHU has no significant effects on lettuce vegetative growth under our soil conditions. In contrast, SHU can be used successfully as a fertilizer of beets. The optimum dose was found at 120kgN ha-1and resulted in average dry weight of 125g. However, if the dose exceeds the optimum levels, the growth of the plant is inhibited. Beets fertilized with SHU does not pose any hygienic risk for human consumption. Our findings represent a promising alternative to propose expanding the use of SHU as fertilizer in medium-sized greenhouses and to provide benefits to families in rural areas, with little or no available water supplies.
Germination of proso millet (Panicum miliaceum L.) grains trigger biochemical changes that augment bioavailability of flower and its utility for gluten-free dietary foods
(2019) Bazhenova, I.A.; Bazhenova, T.S.; Chernova, E.V.
During past decade, there has been an active search for new sources and means, such as biologic modification of raw plant material, to produce bioavailable foods with pre-defined properties. In this study, we tested whether germination of proso millet (Panicum miliaceum L.) grains could be used to increase bioavailability of the flower for gluten-free diets (GFD). Our analysis demonstrated that grains of four selected cultivars had similar germination rates in different media. However, the pikes of amylolytic and proteinase activities were detected at the 2 nd and 3rd days of germination, whereas the pike of lipase activity was associated with the 4th day. The highest and the lowest enzymatic activities were detected in grains germinated in whey and in NaCl, respectively. During germination, cumulative phenolic content increased up to 3.5 times reaching the highest levels by day 5. Based on these data, we produce batches of flour from grains germinated for 3 days and evaluated its utility in producing non-rising cake and shortbread pastry dough. Sensory evaluation of the baked products confirmed that flour from germinated grains could be used for substitution of the wheat flower in the dough. Collectively, our novel findings demonstrated that biochemically defined germination conditions could be used to produce proso millet flour with greater digestibility and nutritive value for the development of new GFD recipes.
The efficiency of nitrogen fertilizer on the dry matter yield of tall fescue and festulolium grown as feedstock for combustion
(2019) Adamovics, A.; Platace, R.; Ivanovs, S.; Gulbe, I.
Grass biomass grows during one vegetation season and can be cultivated and consumed at the place of breeding. Grass biomass can be used not only in traditional feed, but, recently, also for energy production (biogas, solid fuels). The most important economic indicator for any crop is its productivity. The study found that it is important to use nitrogen fertilizer to increase the productivity of tall fescue and festulolium. A significant increase (p < 0.05) in the yield of tall fescue was observed starting from the nitrogen norm of 60 kg ha-1 N. Further increase in nitrogen fertilizer norm provides a significant increase in dry mater yield of tall fescue (reaching 8.64 t ha-1 ) and festulolium (reaching 8.11 t ha-1 ) at 180 kg ha-1 N. The analysis of linear regression coefficients of polynomials showed that the highest nitrogen efficiency in the first year of the use of tall fescue was achieved at the norm of 180 kg ha-1 N, but for festulolium – at the norm of 120 kg ha-1 N. In the following years of tall fescue use, the highest efficiency of nitrogen norms differed: in the 2nd and 4th year of use – at 60 kg ha-1 N, in the 3rd year of use – at 30 kg ha-1 N, and in the 5th year of use – at 120 kg ha-1 N. In contrast, for festulolium, in the 2nd year of use, the highest nitrogen efficiency was reached at the norm of 30 kg ha-1 N, and in the 3rd–5th year of use – at the norm of 60 kg ha-1 N.
Powder particle flow acceleration methods for simulation of interaction with materials used in spacecrafts
(2019) Usherenko, Y.; Mironovs, V.; Lapkovskis, V.; Usherenko, S.; Gluschenkov, V.
In recent decades, the role of satellites for monitoring the condition of agricultural land and forests, as well as in the study of natural resources, has especially increased. The amount of debris in near-Earth space is constantly increasing, which creates a real danger to the operation of satellites and other flying objects. The failures of satellites and spacecrafts increase the cost of their production and inhibit the development of the industry, lead to pollution of near-earth space by space debris. The U.S.-based Space Surveillance Network is currently tracking about 40,000 space objects-the vast majority of which are defunct satellites and fragments from collisions. It was estimated that there are more than 8,378tons of junk around the Earth at speeds of up to 70kmh-1, threatening functioning spacecrafts. Development of a new method for ground-based testing of protective materials, microchips and control systems will enable to avoid further pollution of near-Earth space.This paper discusses methods for accelerating fine particles using explosive devices and an electromagnetic field and the possibility of using them to develop and research protective materials.
Thermoanalytical investigation of selected fuel during isothermal heating
(2019) Vitázek, I.; Ondro, T.; Sunitrová, I.; Majdan, R.; Šotnar, M.
The thermal decomposition of woody biomass was studied using pellets made from residual processing spruce wood (Picea abies). The samples were studied using thermogravimetric analysis in the isothermal regime at the temperatures 275 °C, 300 °C, 325 °C, and 350 °C, which corresponds to the main decomposition region. The results show that the main decomposition region can be described as a volatilisation of the main constituents at a temperature higher than 300 °C. Otherwise, the results indicate, that the lignin does not decompose at lower temperatures. Therefore, it can be concluded that the heating rate is one of the most important parameters that affect the thermal decomposition of lignin and could lead to different interpretations if non-isothermal measurements are used.
Change of physical properties of arable chernozem in the initial period of the after agricultural abandonment regime
(2019) Trushkov, A.V.; Odabashyan, M.Y.; Kazeev, K.Sh.; Kolesnikov, S.I.
A field experiment was conducted in the botanical garden of the South Federal University (Rostov-on-Don, Russia), which was aimed at converting the old arable land plot to the arable regime. Physical properties of chernozems were studied during the first years of the postagrogenic period in different plots, such as: a virgin steppe plot, an arable plot and an abandoned plot. During the course of the experiment it was revealed that physical properties of postagrogenic soils change due to vegetation development after tillage is discontinued. Within three years of research a biological diversity of the floristic composition in the abandoned plot increased from 9 species (during the first year) up to 38 species of plants (3 years later). Vegetation development served as a cause of changes in physical properties of chernozems. Temperature of the abandoned soils decreased along with soil moisture growth, if compared to the relevant indices of the arable plot of land. Owing to the root development and cessation of the agricultural impact, density of the upper horizon in the abandoned plot dropped by 10% on average. A positive correlation was revealed between the chernozem density and its penetration resistance (r = 0.70) and temperature (r = 0.73), whereas an inverse correlation was detected between the chernozem density and its moisture content (r = -1.0).
Entrepreneurship education, entrepreneurship competencies and entrepreneurial activities of alumni: A comparison between the engineering and other graduates of Estonian University of Life Sciences
(2019) Põder, Anne; Lemsalu, Katrin; Nurmet, Maire; Lehtsaar, Jüri; Estonian University of Life Sciences. Institute of Economics and Social Sciences
Entrepreneurial mind-set, knowledge and skills to recognise opportunities and implement ideas are vital competences for achieving success in the midst of rapid global changes. The main purpose of the entrepreneurship education is to foster those competencies. The present paper focuses on the role of the university education in developing various entrepreneurship competences, and the share of entrepreneurs among the alumni. The aim is more specifically to examine the relationship between entrepreneurship education and entrepreneurship competence development in university and the later entrepreneurial activities of the engineering alumni. The analysis is based on a questionnaire survey of alumni entrepreneurship conducted in 2016 as a part of a programme ‘Edu ja Tegu- Development of entrepreneurial education throughout all educational levels’. Chi-square tests, t-tests are used to compare the engineering alumni of Estonian University of Life Sciences with graduates from other fields. The overall share of entrepreneurs among the engineering alumni was 35.6%. The entrepreneurial activities were impacted by the time of graduation. It had also impact of whether the graduates had received entrepreneurship courses during their studies. In comparison with other alumni, the engineering graduates assessed that their university education helped them develop significantly better problem-solving skills, critical thinking, self- evaluation skills, ability to develop new ideas and solutions and leadership skills and obtained significantly less entrepreneurial and financial knowledge during their studies. However, in case of engineering alumni, entrepreneurship education did not have significant impact on their entrepreneurial activities and assessments of competences, thus indicating that other factors are in play.
Cost efficiency of different cropping systems encompassing the energy crop Helianthus annuus L.
(2019) Skoufogianni, E.; Giannoulis, K.D.; Bartzialis, D.; Danalatos, N.G.
Crop rotation and green manure are the most ancient and popular cropping systems. This study sought to analyze the economic efficiency of sunflower where pea (Pisum sativum L.) either harvested or incorporated at the flowering stage in the soil before the sowing of sunflower in Europe and the final agricultural profit of such a cultivation system. Therefore, the main objectiveof this paper is to report the production costs and to find out which of the tested cultivation system gets sunflower cultivation economically viable in Greece and in Mediterranean region. To assess the economic efficiency, three-year field experiments were established in two contrasting environments in central Greece (Trikala and Larisa) and contained three different cultivation practices using legumes comprised the main-factor (T1: control, T2: legume incorporated at the flowering stage, T3: legume incorporated after seed harvest), while nitrogen fertilization comprised the sub-factor (N1:0, N2:50, N3:100 and N4:150 kgNha-1).The results derived from this study revealed the positive effect of the legume incorporation treatment (T2:legume incorporated at the flowering stage) where the final yield increased up to 5tha-1regardless region. Moreover, depending on the year the T2 treatment increases the final yield 30–50%and a yield increase was also noticed to the treatment where the legume was harvested (T3: legume incorporated after seed harvest). Therefore the introduction of this scheme into future land use systems in Greece and more generally in Mediterranean basin should be seriously taken into consideration.
Application of geographically weighted principal components analysis based on soybean yield spatial variation for agro-ecological zoning of the territory
(2019) Zymaroieva, A.; Zhukov, O.; Fedonyuk, T.; Pinkin, A.
In this study, the geographically weighted principal components analysis as an alternative method for agro-ecological characterization of the region was provided. The spatial and temporal distribution pattern of soybean yield was analyzed by using spatial statistics technology, which provided a good reference for agricultural development planning. The soybean yield was selected for the present study because it is a comprehensive indicator reflecting the production potential of the regional agroecosystems. The organized data set, which included the average per year yields of soybean in 10 regions (206 administrative districts) of Ukraine, was used for analysis. The regular temporal trend, specific for each district, was previously extracted from the time series data. The principal components analysis of the detrended data allowed to identify four principal components, which altogether can explain 58% of the soybean yield variation. The geographically weighted principal components analysis allowed to reveal that four spatially determined processes were influencing the yield of soybeans and had the oscillatory dynamics of different periodicity. It was hypothesized that the oscillating phenomena were of ecological nature. Geographically weighted principal component analysis revealed spatial units with similar oscillatory component of soybean yield variation. Our study confirmed the hypothesis that within the studied territory there are zones with the specific patterns of the temporal dynamics of soybean yield, which are uniform within each area but qualitatively different between zones. The territorial clusters within which the temporal dynamics of soybean yield is identical can be considered as agro-ecological zones for soybean cultivation.
Planting and tending productivity comparison in mounds and disc trenches using containerized and bareroot coniferous seedlings
(2019) Makovskis, K.; Lazdina, D.; Kaleja, S.; Spalva, G.; Dumins, K.
In 2016 more then 40,300 ha of forest was regenerated in Latvia, where 13,000 ha were seeded or planted and 30,300 ha were left in natural regeneration. Before planting, usually one of two soil preparation methods are used – mounding or disc trenching. In areas with optimal water regime, disc trenching is used, while in wet areas mounding is used. Tree planting and after planting tending is done manually by hand tools. The aim of the study was to compare planting and tending productivity in different soil preparation methods (mounding and disc trenching) by planting different stocktypes (containerized and bareroot seedlings). Planting time studies were done in 12 sites and tending time studies in 8 sites. In planting time studies, different planting operations were measured and compared. In tending time studies, GPS devices were used, where area, distance and working time (productive and rest) was counted from GPS data. Average planting time for containerized seedlings in disc trenches was 10.3 seconds, while in mounds 9.2 seconds per seedling, an 11% improvement. Average planting time for bareroot seedlings in mounds was 28.3 seconds, while in trenches – 18.2 seconds, a 35% improvement. Tending in trenches was done faster than in mounds. On average, one hectare tending time in mounds was 8.4 hours, while in trenches 7.4 hours, an 11% improvement. Walked distance for 1 hectare tending in mounds was 5.4 km, 7% shorter than the distance of 5.0 km in trenches. Factors that influence planting and tending productivity are soil preparation quality, logging residue, and water level on the site. Data from planting and tending time studies could be used for better plan work activities and select suitable planting material for a particular soil preparation method.
Wheat straw and lipids: UV-mutagenized Yarrowia lipolytica for the conversion of wheat straw hydrolysate into lipids
(2019) Atzmüller, D.; Hawe, F.; Sulzenbacher, D.; Cristobal-Sarramian, A.
Due to the rising energy demand of our modern society and the finite amounts of petroleum-based fuels, renewable forms of energy have become extremely important. Bio-based fuels like bioethanol and biodiesel represent an already applied and accepted alternative. Biodiesel is currently mainly produced from plant oils. A new and promising alternative, which avoids the use of food crops, is the cultivation of the oleaginous yeast Yarrowia lipolytica, which possesses the capacity to accumulate up to 40% of its biomass in form of lipids. Moreover, this non-conventional yeast is able to metabolize a broad range of carbon-sources, presenting a sustainable alternative to reutilize a wide spectrum of waste substrates. This makes it an auspicious candidate for the generation of non-edible oils for biodiesel production. In this work, we aimed to generate a Y. lipolytica mutant strain with enhanced lipid production when grown on wheat straw hydrolysate as sole carbon source. Therefore, UV mutagenesis was applied and mutants with a high-lipid content were selected by their ability to grow in the presence of the fatty acid inhibitor cerulenin. Further, growth of the mutants on wheat straw hydrolysate was evaluated. The fatty acid composition was analysed by GC-FID and the calculated total lipid content revealed an up to 33% increase compared to the wild type strain. Fermentation optimisation and the combination of various waste substrates as carbon sources are expected to further increase the total lipid yield by the Y. lipolytica mutant strain and serve as initial point for its industrial scale evaluation.
Technological features of production of lactate-containing additives from milk whey fermented with lactic acid bacteria
(2019) Eveleva, V.V.; Cherpalova, T.M.; Shipovskaya, E.A.; Korshunova, N. A.
Milk whey becomes a product of interest to researchers and manufacturers due to stricter environmental protection requirements. This paper discusses bioconversion of whey lactose into lactate-containing additives using microorganisms of Lactobacillus genus. The biotransformation of lactose from curd whey and standard solutions of cheese whey into lactic acid derivatives was assessed by the following parameters: the productivity of lactic acid bacteria, the rate of lactose fermentation, the total amount of calcium lactate and its formation rate. Selection of the medium preparation and lactic acid biosynthesis parameters based on these measurements proved to yield optimal results. Lactic acid bacteria from the subgroup of thermophilic bacilli L. acidophilus, L. bulgaricus, L. casei, L. lactis, L. helveticus, L. рlantarum were also tested. The optimal synthetic activity in the terms of calcium lactate turnover and formation rate was demonstrated by L. acidophilus in a medium based on the concentrated whey with 8% lactose.

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