Sirvi Autor "Spalvins, K." järgi

Nüüd näidatakse 1 - 11 11

Analysis of Arabidopsis defensin-like genes and ovule development during fertilization and Fusarium infection
(2017) Spalvins, K.; Blumberga, D.
Defensins are small, highly stable antimicrobial peptides. Many defensin-like (DEFL) peptides found in flowering plant Arabidopsis thaliana are believed to have role in either natural immunity or cell-to-cell communication during fertilization. However, little is known about the DEFL peptides and their functions during these events. The goal of this work is to investigate the genes encoding selected DEFLs by observing their expression patterns during fertilization and Fusarium graminearum infection. According to the results 4 selected genes of interest (GOI) are downregulated after fertilization and infection and mock treatments are causing degradation and delay of development in treated ovules.
Herbicide-based selection of mutants for improved single cell protein synthesis: application and procedures
(Estonian University of Life Sciences, 2024) Raita, S.; Berzina, I.; Kusnere, Z.; Kalnins, M.; Kuzmika, I.; Spalvins, K.
Enhancement of industrially important microbial strains using random mutagenesis is widely used. Screening of potential mutants accelerates the selection of mutants with desired properties such as improved synthesis of lipids, carotenoids, enzymes, or increased tolerance to unfavourable conditions. However, random mutagenesis has not been used to improve protein biosynthesis in microorganisms, and a method for screening these mutants has not yet been developed. The present work reviews the new concept of using herbicides as tools for selecting mutant microorganisms with improved protein biosynthesis. Several pure herbicide substances are amino acid inhibitors whose specific action can be used as a selective pressure for screening protein-rich mutants. The article summarises information about thirteen amino acid inhibitors that inhibit microorganisms and provides data on applicable doses and specifics of use. The article contains mutagenesis protocols and mutant selection strategies, supplemented by theoretical considerations for practical application.
Improving single cell protein yields and amino acid profile via mutagenesis: review of applicable amino acid inhibitors for mutant selection
(2021) Spalvins, K.; Raita, S.; Valters, K.; Blumberga, D.
Single cell protein (SCP) is a good alternative for substituting plant and animal derived dietary proteins, since SCP production is more environmentally friendly, consumes less water, requires smaller land areas and its effect on climate change is much less pronounced than it is in the case of agriculturally derived proteins. Another advantage of SCP is that it is possible to use a wide variety of biodegradable agro-industrial by-products for the cultivation of SCP producing microorganisms. However, to make single cell protein technology more widely available and improve its economic viability in such markets as animal and fish feed industries, it is necessary to improve the protein yields and amino acid profiles in microorganism strains capable of using agro-industrial by-products. One way to improve the strains used in the process is to create and select SCP-rich mutants. In this review authors propose a novel approach to create SCP-rich mutants with improved total protein content and essential amino acid profiles. In this approach amino acid inhibitors are used to create selective pressure on created mutants. It is expected that mutants with the most pronounced growth would either have higher total protein content, increased essential amino acid concentrations or both, when cultivated on selective plates containing one or multiple amino acid inhibitors. This paper reviews the most suitable groups of amino acid inhibitors that could be used for selection of new strains of SCP-producing microorganisms.
In search of the best technological solutions for creating edible protein-rich mutants: a multi-criteria analysis approach
(Estonian University of Life Sciences, 2024) Berzina, I.; Raita, S.; Kalnins, M.; Spalvins, K.; Kuzmika, I.
Single-cell protein (SCP) is a promising alternative for replacing plant and animalderived dietary proteins. SCP contains essential nutrients and high levels of essential amino acids (AA). Given the versatility of microbial strains and waste substrates that can be used as feedstocks, many variations of production processes can be explored. Improving these microorganism strains by enhancing their properties and productivity is vital to increasing SCP competitiveness. One of the options to enhance microorganism strains would be by creating mutants with better AA profiles. By using mutagenesis and AA inhibitors it should be possible the create novel strains with improved AA-producing properties. The use of AA inhibitors to promote selective pressure on SCP-producing strains is a novel concept and is not a widely explored approach, therefore, the further development of this method should be explored. This paper used a multi-criteria decision analysis method to evaluate different technological factors vital for creating protein-rich mutants. These factors are microorganism strains, agro-industrial waste substrates used as process feedstocks, AA inhibitors, and mutagenesis methods. Microorganisms Candida utilis and Bacillus subtilis showed the highest potential for being used. Molasses was the ‘closest to the ideal’ substrate to be used as feedstock for SCP production. As the most promising mutagenesis method ethyl methane sulphonate was selected. Glufosinate ammonium and methionine sulfoximine for both bacteria and fungi were identified as the best inhibitors for SCP-rich mutant selection. Identified combinations of optimal solutions for microorganisms, substrates, inhibitors, and mutagenesis techniques should be further investigated and evaluated in laboratory settings. This could help to increase SCP's competitiveness as a sustainable protein source.
Multi-criteria decision analysis of wood waste ash and glass foam: toward sustainable material selection for biomethanation
(Estonian University of Life Sciences, 2024) Kusnere, Z.; Lauka, D.; Spalvins, K.
The study examines the potential applications of wood waste ash and waste glass, byproducts of various industrial processes, which have conventional applications such as composting and soil improvement. A new development, vulcanised wood ash material, is studied analysed, drawing parallels between its industrial production process and that of clay pellets. Vulcanised wood ash material and glass foam, which are characterised by advantageous chemical and physical properties, are proving to be versatile resources for various technical applications. Employing a systematic decision-making approach, the study utilises multi-criteria decision analysis and the Technique for Order of Preference by Similarity to Ideal Solution method to evaluate materials for biotrickling filter reactors in ex-situ biomethanation. The comparative analysis includes ash filter material, glass foam, and other industry alternatives, emphasising environmental impacts. The findings reveal expanded clay pellets as the most suitable carrier material, closely followed by polyurethane foam, while glass foam demonstrates remarkable performance despite ranking third. The innovative qualities of glass foam, such as high porosity and thermal insulation, position it as a viable option for biotrickling filter reactors, promoting sustainable practices and circular economy principles. However, further development is required to optimise vulcanised wood ash for biomethanation, potentially enhancing its efficiency through pH adjustment and porosity optimisation.
Packing materials for biotrickling filters used in biogas upgrading – biomethanation
(2021) Kusnere, Z.; Spalvins, K.; Blumberga, D.; Veidenbergs, I.
One of the promising methods of biogas upgrading is biological methanation (biomethanation). During biomethanation process hydrogenotrophic microorganisms use carbon dioxide from biogas and added hydrogen to generate biomethane. Application of biotrickling filter reactors is one of the prospective biotechnologies for methanation where hydrogenotrophic methanogens are immobilized over a material that is used in reactor. Packing materials for biomethanation are critical in terms of hydrogenotrophic methanogens immobilization on the surface of packing material. It acts as support for biofilm growth. Therefore, characteristics of filter material are important parameters that influence the growth of microorganisms and methane production. Factors, such as optimal specific surface area and porosity are important to sustain growth and activity of microorganisms. Optimal particle size and capability to mechanically resist compaction ensures avoiding high pressure drop. Optimal particle size also ensures uniform gas flow as gases distribute through the packing material. This review paper summarizes and compare the characteristics of different packing materials important for biomethanation through ex-situ biotrickling filter reactor systems.
Prospect on agro-industrial residues usage for biobutanol production
(2021) Raita, S.; Spalvins, K.; Blumberga, D.
Climate changes, environmental pollution and resource depletion are one of the numerous major problems humanity faces. United Nations sustainable development goals are aimed at solving these problems. The requirement for affordable, renewable, sustainable, biodegradable and environmentally friendly fossil fuel alternative sources is prompted by the development and advancement of biofuel production technologies. Of the various biofuel alternatives, biobutanol has increased the interests of researchers due to its desirable characteristics such as hydrophobicity, relatively high heating value and energy density, relatively low vapour pressure, etc. Nowadays, sustainable production of the biobutanol depends on the used feedstock source and its pre-treatment method, selected enhancing microorganism strain, acetone–butanol–ethanol fermentation effectiveness and titer of biobutanol. The main research challenges in biobutanol production are an improvement of production efficiency and increasing the financial viability of the technology. This review summarizes the latest results of lignocellulosic components content and fermentable sugars composition in different agro-industrial residues; biobutanol production depending on the Clostridium enhancing strategy, process optimization and selection of substrate. Such analysis provides a better perception of the capability of using agro-industrial residues for biobutanol production efficiency.
A simple tool for resource availability optimization: A case study of dairy whey supply for single cell protein and oil production in Latvia
(2020) Spalvins, K.; Blumberga, D.
Single cell proteins (SCP) and oils (SCO) are promising alternatives for replacing conventional feed ingredients in animal and aquaculture fish feeds. The production costs of SCP and SCO need to be reduced by using inexpensive substrates (production by-products) suitable for cultivation of protein and oil producing microorganisms. This article reviews the availability of milk processing by-product – whey in Latvia, in 2019. Additionally, a simple production plant location optimization model is proposed, where no prior knowledge of location optimization or experience with dedicated software is required from the user. The case study demonstrated that the model is valid, and it can be used as a simple tool for resource acquisition from multiple sources to single production plant.
Single cell oil production from waste biomass: review of applicable agricultural by-products
(2019) Spalvins, K.; Blumberga, D.
Single cell oil (SCO) is an attractive alternative source of oils, since it can be used as feedstock in biofuel production and also have been recognized as viable option in production of essential fatty acids suitable for either human nutrition or as supplementary in animal feeds. However, the usability of SCO is limited due to the high price of raw materials used in the fermentation process. This problem can be tackled by using low-cost agro-industrial residues which are applicable for SCO production. Use of these by-products as the main carbon source in fermentations not only significantly reduces the overall production costs of SCO, but also enables treatment of generated waste streams, thus reducing the negative impact on environment. Since various biodegradable agro-industrial by-products can be used in microbial fermentations, this review aims to categorize and compare applicable agricultural residues by their availability, necessary pre-fermentation treatments, SCO yields and current usability in other competing sectors.
Single cell protein production from waste biomass: review of various agricultural by-products
(2018) Spalvins, K.; Ivanovs, K.; Blumberga, D.
Agricultural waste constitutes for most of the manmade waste streams. Processing of biodegradable waste materials ensures the treatment of harmful substances and allows to reduce environmental pollution. In addition, conversion of these waste materials in value - added products makes these recycling methods more economically viable. Single - cell protein is one of the value - added products that can be produced by microbial fermentation of waste materials. In this review various biodegradable agricultural by - prod ucts as substrates for production of SCP are categorized and compared.
System dynamics modeling for precision beekeeping: Queen rearing optimization for advanced apiary management
(Estonian University of Life Sciences, 2024) Smilga-Spalvina, A.; Spalvins, K.; Veidenbergs, I.
The authors propose system dynamics modelling as a new direction in Precision Beekeeping. By modeling the production process in beekeeping, it is possible to forecast the potential production capacity before the season, using the resources available to the beekeeper. The model included in this article reflects one specialisation of beekeeping - queen bee rearing, from the process of queen bee breeding up to the sale of queen bees throughout the entire season. The model helps beekeepers make decisions about the workforce needed to maintain the desired production volume, expected income and costs and resource allocation.

Sirvi Autor "Spalvins, K." järgi

Tulemused lehekülje kohta

Sorteerimisvalikud