Fuel ethanol from lignocellulose could be important source of renewable energy. However, to make the process feasible, more efficient microbial fermentation of pentose sugars, mainly xylose, should ...be achieved. The native xylose-fermenting thermotolerant yeast Ogataea polymorpha is a promising organism for further development. Efficacy of xylose alcoholic fermentation by O. polymorpha was significantly improved by metabolic engineering. Still, genes involved in regulation of xylose fermentation are insufficiently studied. We isolated an insertional mutant of O.polymorpha with impaired ethanol production from xylose. The insertion occurred in the gene HXS1 that encodes hexose transporter-like sensor, a close homolog of Saccharomyces cerevisiae sensors Snf3 and Rgt2. The role of this gene in xylose utilization and fermentation was not previously elucidated. We additionally analyzed O.polymorpha strains with the deletion and overexpression of the corresponding gene. Strains with deletion of the HXS1 gene had slower rate of glucose and xylose consumption and produced 4 times less ethanol than the wild-type strain, whereas overexpression of HXS1 led to 10% increase of ethanol production from glucose and more than 2 times increase of ethanol production from xylose. We also constructed strains of O.polymorpha with overexpression of the gene AZF1 homologous to S. cerevisiae AZF1 gene which encodes transcription activator involved in carbohydrate sensing. Such transformants produced 10% more ethanol in glucose medium and 2.4 times more ethanol in xylose medium. Besides, we deleted the AZF1 gene in O. polymorpha. Ethanol accumulation in xylose and glucose media in such deletion strains dropped 1.5 and 1.8 times respectively. Overexpression of the HXS1 and AZF1 genes was also obtained in the advanced ethanol producer from xylose. The corresponding strains were characterized by 20-40% elevated ethanol accumulation in xylose medium. To understand underlying mechanisms of the observed phenotypes, specific enzymatic activities were evaluated in the isolated recombinant strains. This paper shows the important role of hexose sensor Hxs1 and transcription factor Azf1 in xylose and glucose alcoholic fermentation in the native xylose-fermenting yeast O. polymorpha and suggests potential importance of the corresponding genes for construction of the advanced ethanol producers from the major sugars of lignocellulose.
Optical Properties of CdS Thin Films Petrus, R. Yu; Ilchuk, H. A.; Kashuba, A. I. ...
Journal of applied spectroscopy,
03/2020, Letnik:
87, Številka:
1
Journal Article
Recenzirano
We have studied the physical properties of CdS thin films obtained by high-frequency magnetron sputtering. We have determined the optical constants and the bandgap width for the studied fi lms (Е
g
= ...2.39 eV). The spectral dependences of the refractive index, the absorption coefficient, and the extinction coefficient were obtained from the transmission spectra at room temperature. The optical parameters of the films were determined using a singleoscillator model, and also the Cauchy and Sellmeier equations.
The methylotrophic yeast Komagataella phaffii is considered one of the most effective producers of recombinant proteins of industrial importance. Effective producers should be characterized by the ...maximal reduction of degradation of the cytosolic recombinant proteins. The mechanisms of degradation of cytosolic proteins in K. phaffii have not been elucidated; however, data suggest that they are partially degraded in the autophagic pathway. To identify factors that influence this process, a developed system for the selection of recombinant strains of K. phaffii with impaired autophagic degradation of the heterologous model cytosolic protein (yeast β‐galactosidase) was used for insertional tagging of the genes involved in cytosolic proteins degradation. In one of the obtained strains, the insertion cassette disrupted the open reading frame of the gene encoding β‐1,6‐N‐acetylglucosaminyltransferase. A recombinant strain with deletion of this gene was also obtained. The rate of degradation of the β‐galactosidase enzyme was two times slower in the insertion mutant and 1.5 times slower in the deletion strain as compared to the parental strain with native β‐1,6‐N‐acetylglucosaminyltransferase. The rate of degradation of native K. phaffii cytosolic and peroxisomal enzymes, formaldehyde dehydrogenase, formate dehydrogenase, and alcohol oxidase, respectively, showed similar trends to that of β‐galactosidase—slower degradation in the deletion and insertional mutants as compared to the wild‐type strain, but faster protein degradation relative to the strain completely defective in autophagy. We conclude that K. phaffii gene designated ACG1, encoding β‐1,6‐N‐acetylglucosaminyltransferase, is involved in autophagy of the cytosolic and peroxisomal proteins.
Disruption of the gene ACG1 encoding β‐1,6‐N‐acetylglucosaminyltransferase in K. phaffii affects autophagic degradation of cytosolic and peroxisomal proteins
Take‐Away
Gene encoding β‐1,6‐N‐acetylglucosaminyltransferase in K. phaffii was named ACG1.
Disruption of the ACG1 affects autophagic degradation of proteins in K. phaffii.
Degradation of both cytosolic and peroxisomal proteins was affected.
Human genes with similar functions did not affect autophagy.
Abstract
Scientific research and the experience of leading dairy enterprises show that the level of modernization of production, the quality of various management systems for the maintenance, feeding ...and use of livestock genetic resources, as well as the professional level of human resources are important components of effective milk production. Nowadays, the active use of “smart” systems for managing production processes has acquired priority importance. At the same time, the implementation of these systems makes relevant the issues of dairy business efficiency and food security. Milk production is a rather complicated process and its efficiency depends on many aspects. The given analytical research is based on the results of the Novgorod region agricultural dairy enterprises and the changes that appeared under the influence of the current regional policy. Particular attention is paid to the development of dairy farming at the regional level, its goals, objectives, and activities. The researcher analyzes the implementation of the State Program of the Novgorod Region “Development of Agriculture in the Novgorod Region for 2019-2024”, that provides for an increase in local milk production due to accelerated solution of socio-economic problems in agriculture. The article argues that the work on milk production efficiency should be carried out within the framework of the priority regional project “Development of Dairy Farming” aimed at increasing the efficiency of investments. Besides, according to this project, regional agricultural organizations can increase milk production to 55 thousand tons by the year 2025. The flexible investment legislation of the region allows implementing large investment projects in the region; in the future, it would increase the milk production. The introduction of modern agricultural solutions at enterprises would ensure the systemic development of dairy farming in the region and, accordingly, effective milk production.
Abstract
The current development of dairy cattle breeding raises an urgent problem of feeding improvement; it concerns the preparation of high-quality feed and diets depending on the physiological ...state of the animal. While solving this problem, it is necessary to pay special attention to the organization and improvement of biochemical control of full-fledged feeding of cows. This research pays considerable attention to the theoretical component of the topic, namely, it justifies the significance of zootechnic and physiological-biochemical methods used on dairy farms in order to control the completeness of cows feeding. The analytical study is based on the monitoring of biochemical control methods used in the studied farm for the purpose of prompt response to the organization of full-fledged feeding of cows; the recommendations are given on testing biological fluids in real time. The research also touches upon the aspect associated with metabolic disorders, which appears with an imbalance of vital substances in the diet and does not display any symptoms. The long-term influence of unbalanced feeding leads to diseases of animals and, accordingly, to economic damage due to a sharp decrease in milk production, reproductive capacity and other indicators. As a result, the genetic potential of animals is not fully realized. In this regard, it is evidently confirmed that in order to increase the productivity of black-and-white cows, it is necessary to constantly improve and optimize their feeding diets, to monitor the physiological state of animals using biochemical indicators.
The effect of pressure on the electronic band structure of CdSe and CdS compounds has been investigated using the density functional theory. In this approach, the generalized gradient approximation ...(GGA) and the Purdue-Burke-Ernzerhof (PBEsol) parameterization were used for the exchange-correlation potential calculation. The ground-state properties are determined for the bulk materials (CdS and CdSe) in wurtzite phase. Structure and electronic properties are studied in the range of hydrostatic pressures between 0 and 100 GPa. The electron band-energy structure and density of states were calculated at different pressures. The equilibrium structural parameters, bulk modules and bandgaps are calculated and compared with the available experimental data and other theoretical results. The shift in the energy gap, total energy and lattice parameters of CdSe and CdS crystals with pressure is determined and compared with other known data.
Scientific research and practice of leading agricultural enterprises show that innovative technologies are the main condition and the key factor for sustainable development of dairy farming. In ...modern conditions, the use of digital technologies, active implementation and use of smart automated process control systems are a priority. The studies conducted have shown that competitive struggle for markets, and increased consumption of milk and dairy products accelerate advancement of digital technologies in the dairy industry and provide access to the trajectory of sustainable development. At the same time, implementation of these technologies makes actual the issues of increased efficiency of the agribusiness. In modern conditions, digitalization of the dairy industry helps farm managers to efficiently fulfill the current tasks faced by the personnel, and therefore to ensure food security in the country and in the world. Introduction of digital technology suggests high demands to the professional level of the personnel. Sustainable development of dairy farming is challenging, and it depends on a number of factors. It requires active use of digital technologies by agricultural enterprises, appropriate organizational support, and support from federal and regional authorities. The paper highlights that development of dairy farming in Novgorod region should be carried out as part of the priority regional project Development of Dairy Farming, which increases the efficiency of investment mobilization. Flexibility of the investment legislation in the region enables implemention of large-scale investment projects, which can increase milk production in the future. Implementation of digital technologies and system digital agro-solutions on digital farms will make a breakthrough in dairy farming in the region in the coming years.
The development of the export potential and the formation of the export policy of the region are an important process, including domestic and foreign policy components. Improving the export activity ...of the subject is complicated by the presence of crisis phenomena, both in the economy and in the social sphere, similar processes are observed in the agricultural sector at the present stage. In this study, the authors paid considerable attention to the theoretical component of the topic, namely, they justified the importance of export operations as a strategic resource for the development of the territory, characterized the totality of factors determining the export potential of the territory, and updated the need for an analytical study of the composition, structure and dynamics of exports in modern conditions. The basis of the analytical study was the volume of agricultural exports of Novgorod region and its changes under the influence of the existing regional policy. Particular attention was paid to determining the place of the agricultural export policy at the federal and regional levels, its goals, objectives, activities and emerging risks in the implementation process, through analysis of the national project "International Cooperation and Export", as well as federal and regional projects developed as part of national project. The study of the stated problems was also focused on the aspect related to assessing the degree of influence of export activity in the regional agro-industrial complex (AIC) on the economic and social indicators of the development of the territory, the proof of which was the confirmation of the relationship with the use of parametric methods.
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