Pub Date : 2023-01-01DOI: 10.21285/2227-2925-2022-12-4-547-556
Z. Sherova, A. Nasriddinov, S. Kholov, S. Usmanova, Z. Muhidinov
Silk sericin comprises a globular water-soluble protein that surrounds silk fibres, sticking them together and providing cocoon adhesion. Sericin was isolated from the extract solution in two ways: the first sample was obtained by concentrating the filtered extract at low pressure (SLP); the second sample was obtained by ultrafiltration (SUF) using a membrane. In this work, the size exclusion-high-performance liquid chromatography involving viscometry and refractive index detectors was used to determine the molecular weight and conformation of sericin polypeptides obtained from cocoons of the Bombyx mori silkworm. The aggregation processes of silk sericin protein under various isolation conditions from the solution were considered. It was shown that sericin macromolecules are present as a monodisperse polypeptide at low concentrations, which aggregates at concentrations greater than 1–2 mg/ml. The obtained data indicate that, along with the parameters of the extraction process, the conditions for its isolation from the solution, including temperature, pressure and degree of concentration, affect the molecular weight and aggregative behaviour of the protein. The results confirm and complement previously obtained data on the influence of various factors on the association of protein macromolecules in solution. The resulting sericin fractions can find many applications, including materials for tissue engineering, coatings for surface modification, cell culture media, cosmetics, as well as food additives and medical biomaterials.
{"title":"Molecular weight and molecular weight distribution of sericin protein extracted from cocoon waste of Bombyx mori","authors":"Z. Sherova, A. Nasriddinov, S. Kholov, S. Usmanova, Z. Muhidinov","doi":"10.21285/2227-2925-2022-12-4-547-556","DOIUrl":"https://doi.org/10.21285/2227-2925-2022-12-4-547-556","url":null,"abstract":"Silk sericin comprises a globular water-soluble protein that surrounds silk fibres, sticking them together and providing cocoon adhesion. Sericin was isolated from the extract solution in two ways: the first sample was obtained by concentrating the filtered extract at low pressure (SLP); the second sample was obtained by ultrafiltration (SUF) using a membrane. In this work, the size exclusion-high-performance liquid chromatography involving viscometry and refractive index detectors was used to determine the molecular weight and conformation of sericin polypeptides obtained from cocoons of the Bombyx mori silkworm. The aggregation processes of silk sericin protein under various isolation conditions from the solution were considered. It was shown that sericin macromolecules are present as a monodisperse polypeptide at low concentrations, which aggregates at concentrations greater than 1–2 mg/ml. The obtained data indicate that, along with the parameters of the extraction process, the conditions for its isolation from the solution, including temperature, pressure and degree of concentration, affect the molecular weight and aggregative behaviour of the protein. The results confirm and complement previously obtained data on the influence of various factors on the association of protein macromolecules in solution. The resulting sericin fractions can find many applications, including materials for tissue engineering, coatings for surface modification, cell culture media, cosmetics, as well as food additives and medical biomaterials.","PeriodicalId":20601,"journal":{"name":"PROCEEDINGS OF UNIVERSITIES APPLIED CHEMISTRY AND BIOTECHNOLOGY","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79760579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.21285/2227-2925-2022-12-4-514-520
S. Dorzhieva, J. Bazarova
This work addressed the directed synthesis of a new phase Rb5Li1/3Zr5/3(MoO4)6, along with the determination of its crystallographic, thermal and electrophysical properties. The directed synthesis of the Rb5Li1/3Zr5/3(MoO4)6 phase was carried out using the solid-state reaction in the temperature range of 350–470 °C. According to differential scanning calorimetry, the synthesised compound Rb5Li1/3Zr5/3(MoO4)6, crystallised in trigonal form (space group R3c, Z = 6), undergoes a diffused first-order phase transition. The structure of triple molybdate Rb5Li1/3Zr5/3(MoO4)6 comprises MoO4 tetrahedra and octahedrally coordinated MO6-polyhedra. This structure is characterised by a statistical distribution of lithium and zirconium atoms in the M position (M1 = 0.790 Zr + 0.210 Li, M2 = 0.877 Zr + 0.123 Li). Rb atoms are located in the large voids of the tetrahedronoctahedral framework. The electrophysical properties of triple molybdate Rb5Li1/3Zr5/3(MoO4)6 having a scaffold structure favourable for ion transport, were studied. The correlation between dielectric and thermal characteristics in the high-temperature region near the phase transition was revealed. The temperature and frequency dependences of electrical conductivity were measured at 473–873 K in heating and cooling modes in the frequency range of 1–10 kHz. The compound exhibited a high thermally activated conductivity, reaching 1.48·10-2 Cm K/cm with activation energy in the range of 0.6–0.8 eV at a temperature of 480 °C. Well-shaped semicircles in the low-frequency region and unresolved arcs in the high-frequency region changing with increasing temperature were observed in the impedance spectra of ceramic Rb5Li1/3Zr5/3(MoO4)6 sample at various temperatures. The evolution of the imaginary part (Z'') as a function of the real part (Z') of the complex impedance resembled that of the complex impedance for compounds having ionic conductivity.
{"title":"Synthesis, thermal and dielectric characteristics of Rb5Li1/3Zr5/3(MoO4)6","authors":"S. Dorzhieva, J. Bazarova","doi":"10.21285/2227-2925-2022-12-4-514-520","DOIUrl":"https://doi.org/10.21285/2227-2925-2022-12-4-514-520","url":null,"abstract":"This work addressed the directed synthesis of a new phase Rb5Li1/3Zr5/3(MoO4)6, along with the determination of its crystallographic, thermal and electrophysical properties. The directed synthesis of the Rb5Li1/3Zr5/3(MoO4)6 phase was carried out using the solid-state reaction in the temperature range of 350–470 °C. According to differential scanning calorimetry, the synthesised compound Rb5Li1/3Zr5/3(MoO4)6, crystallised in trigonal form (space group R3c, Z = 6), undergoes a diffused first-order phase transition. The structure of triple molybdate Rb5Li1/3Zr5/3(MoO4)6 comprises MoO4 tetrahedra and octahedrally coordinated MO6-polyhedra. This structure is characterised by a statistical distribution of lithium and zirconium atoms in the M position (M1 = 0.790 Zr + 0.210 Li, M2 = 0.877 Zr + 0.123 Li). Rb atoms are located in the large voids of the tetrahedronoctahedral framework. The electrophysical properties of triple molybdate Rb5Li1/3Zr5/3(MoO4)6 having a scaffold structure favourable for ion transport, were studied. The correlation between dielectric and thermal characteristics in the high-temperature region near the phase transition was revealed. The temperature and frequency dependences of electrical conductivity were measured at 473–873 K in heating and cooling modes in the frequency range of 1–10 kHz. The compound exhibited a high thermally activated conductivity, reaching 1.48·10-2 Cm K/cm with activation energy in the range of 0.6–0.8 eV at a temperature of 480 °C. Well-shaped semicircles in the low-frequency region and unresolved arcs in the high-frequency region changing with increasing temperature were observed in the impedance spectra of ceramic Rb5Li1/3Zr5/3(MoO4)6 sample at various temperatures. The evolution of the imaginary part (Z'') as a function of the real part (Z') of the complex impedance resembled that of the complex impedance for compounds having ionic conductivity.","PeriodicalId":20601,"journal":{"name":"PROCEEDINGS OF UNIVERSITIES APPLIED CHEMISTRY AND BIOTECHNOLOGY","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82056388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-09DOI: 10.21285/2227-2925-2022-12-3-471-478
A. S. Lukin, R. G. Zhitov, V. V. Bayandin, N. S. Shaglaeva
The paper studies how the nature of the plasticizer affects the properties of polymer-bitumen compositions using the fluorescence microscopy. The current petroleum road bitumen used for the construction of road, bridge, and airfield pavements does not meet the requirements for cracking/heat resistance, elasticity, and adhesion to the mineral material surface. Pavement performance characteristics can be significantly improved by introducing thermoplastic elastomers, plasticizers, and surfactants into the composition of petroleum road bitumen. The best results were obtained when using a block copolymer of styrene and butadiene, industrial oil, and cationic surfactant on the basis of polyaminoamides and polyaminoimidazolines. The choice of industrial oil as a plasticizer is attributed to its good compatibility with bitumen and polymer, as well as its high flash point (200 °С). The content of paraffin-naphthenic hydrocarbons in industrial oil is over 70%. Although industrial oil is produced in large quantities, an acute shortage of this petrochemical product is observed due to its wide application; thus, intensive studies are underway to replace industrial oil in the composition of the polymer-bitumen binder. It is proposed to use heavy gas oil produced via catalytic cracking and delayed coking, heavy pyrolysis tar, solvent-extracted oil, and tall oil as plasticizers in the creation of the polymer-bitumen binder. In this connection, the effect of proposed plasticizers on the colloidal structure of the polymer-bitumen binder was studied using the method of fluorescence microscopy. Initial polymer-bitumen binders were produced at ANHK (Angarsk) according to GOST R 52056-2003 Polymer-Bitumen Road Binders Based on Styrene-Butadiene-Styrene-Type Block Polymers. The group composition of the plasticizers under study was determined. It was shown that in order to obtain a polymer-bitumen binder resistant to stratification, plasticizers having a content of aromatic compounds of over 60% are required.
利用荧光显微镜研究了增塑剂的性质对聚合物沥青组成物性能的影响。目前用于道路、桥梁和机场路面建设的石油公路沥青，不符合抗裂/耐热性、弹性和与矿物材料表面的附着力要求。通过在石油沥青中引入热塑性弹性体、增塑剂和表面活性剂，可以显著改善路面性能。以聚酰胺和聚胺咪唑啉为基础，用苯乙烯-丁二烯嵌段共聚物、工业油和阳离子表面活性剂进行改性，效果最好。选择工业油作为增塑剂是由于它与沥青和聚合物的良好相容性，以及它的高闪点(200°С)。工业油中石蜡环烃的含量在70%以上。虽然工业用油产量很大，但由于其广泛应用，这种石化产品严重短缺;因此，人们正在深入研究如何在聚合物-沥青粘结剂的组成中取代工业用油。建议使用催化裂化和延迟焦化生产的重质气油、重质热解焦油、溶剂萃取油和塔尔油作为增塑剂制备聚合物-沥青粘结剂。在这方面，采用荧光显微镜的方法研究了增塑剂对聚合物-沥青粘合剂胶体结构的影响。根据GOST R 52056-2003基于苯乙烯-丁二烯-苯乙烯型嵌段聚合物的聚合物-沥青道路粘合剂，ANHK (Angarsk)生产了最初的聚合物-沥青粘合剂。测定了所研究的增塑剂的基团组成。结果表明，为了获得抗分层的聚合物-沥青粘结剂，需要芳香族化合物含量超过60%的增塑剂。
{"title":"Study into the effect of plasticizer nature on the properties of polymer-bitumen compositions via fluorescence microscopy","authors":"A. S. Lukin, R. G. Zhitov, V. V. Bayandin, N. S. Shaglaeva","doi":"10.21285/2227-2925-2022-12-3-471-478","DOIUrl":"https://doi.org/10.21285/2227-2925-2022-12-3-471-478","url":null,"abstract":"The paper studies how the nature of the plasticizer affects the properties of polymer-bitumen compositions using the fluorescence microscopy. The current petroleum road bitumen used for the construction of road, bridge, and airfield pavements does not meet the requirements for cracking/heat resistance, elasticity, and adhesion to the mineral material surface. Pavement performance characteristics can be significantly improved by introducing thermoplastic elastomers, plasticizers, and surfactants into the composition of petroleum road bitumen. The best results were obtained when using a block copolymer of styrene and butadiene, industrial oil, and cationic surfactant on the basis of polyaminoamides and polyaminoimidazolines. The choice of industrial oil as a plasticizer is attributed to its good compatibility with bitumen and polymer, as well as its high flash point (200 °С). The content of paraffin-naphthenic hydrocarbons in industrial oil is over 70%. Although industrial oil is produced in large quantities, an acute shortage of this petrochemical product is observed due to its wide application; thus, intensive studies are underway to replace industrial oil in the composition of the polymer-bitumen binder. It is proposed to use heavy gas oil produced via catalytic cracking and delayed coking, heavy pyrolysis tar, solvent-extracted oil, and tall oil as plasticizers in the creation of the polymer-bitumen binder. In this connection, the effect of proposed plasticizers on the colloidal structure of the polymer-bitumen binder was studied using the method of fluorescence microscopy. Initial polymer-bitumen binders were produced at ANHK (Angarsk) according to GOST R 52056-2003 Polymer-Bitumen Road Binders Based on Styrene-Butadiene-Styrene-Type Block Polymers. The group composition of the plasticizers under study was determined. It was shown that in order to obtain a polymer-bitumen binder resistant to stratification, plasticizers having a content of aromatic compounds of over 60% are required.","PeriodicalId":20601,"journal":{"name":"PROCEEDINGS OF UNIVERSITIES APPLIED CHEMISTRY AND BIOTECHNOLOGY","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81547246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-09DOI: 10.21285/2227-2925-2022-12-3-485-490
A. Pomortsev, N. Dorofeev, S. Adamovich, E. N. Oborina
In order to manage field crop production, reduce the negative impact of abiotic factors, and increase productivity and product quality, the modern agricultural industry uses chemical compounds analogous to endogenous phytohormones. Some of these substances are physiologically valuable due to their capability to improve the resistance of plants to adverse environmental factors. The increased interest in such preparations can be attributed to their low cost and effectiveness at low concentrations. The effect of a protatrane mixture (a, b, c) on changes in the physiological parameters (growth characteristics; water status) of spring wheat (Triticum aestivum L.) was studied at low concentrations (10−6 and 10−9 g/L) under chloride salinity conditions. The plants were grown under laboratory conditions in a CLF PlantClimatics chamber, in which untreated and chemically treated spring wheat seeds were evaluated for changes in morphological and physiological parameters under salt stress conditions (150 mM NaCl). The analysis of obtained data revealed that protatranes have a positive effect on the morphometric parameters and water status of plants under chloride salinity conditions. Thus, the examined substances decrease the inhibition of growth processes under chloride salinity conditions. The treatment of seeds with the studied substances increases the tissue water content while decreasing the osmotic potential drop in leaves and roots. Irrespective of the mix ratio, protatranes help to improve the plant water status and mitigate the negative effects of chloride salinity on plant growth.
为了管理田间作物生产，减少非生物因素的负面影响，提高生产力和产品质量，现代农业工业使用类似于内源植物激素的化合物。其中一些物质具有生理价值，因为它们能够提高植物对不利环境因素的抗性。人们对这类制剂的兴趣日益增加，可归因于它们在低浓度下的低成本和有效性。甲、乙、丙混合剂对生理参数(生长特性;在低浓度(10−6和10−9 g/L)氯盐条件下，研究了春小麦(Triticum aestivum L.)的水分状况。在CLF植物气候实验室条件下，对未经处理和化学处理的春小麦种子在150 mM NaCl盐胁迫条件下的形态和生理参数变化进行了评价。结果表明，在氯盐条件下，protatranes对植物形态参数和水分状况有积极影响。因此，所检测的物质在氯盐条件下降低了对生长过程的抑制作用。用所研究的物质处理种子增加了组织含水量，同时降低了叶片和根的渗透电位下降。无论混合比例如何，prottranes都有助于改善植物水分状况，减轻氯盐对植物生长的负面影响。
{"title":"Effect of protatranes on the physiological parameters of spring wheat under chloride salinity conditions","authors":"A. Pomortsev, N. Dorofeev, S. Adamovich, E. N. Oborina","doi":"10.21285/2227-2925-2022-12-3-485-490","DOIUrl":"https://doi.org/10.21285/2227-2925-2022-12-3-485-490","url":null,"abstract":"In order to manage field crop production, reduce the negative impact of abiotic factors, and increase productivity and product quality, the modern agricultural industry uses chemical compounds analogous to endogenous phytohormones. Some of these substances are physiologically valuable due to their capability to improve the resistance of plants to adverse environmental factors. The increased interest in such preparations can be attributed to their low cost and effectiveness at low concentrations. The effect of a protatrane mixture (a, b, c) on changes in the physiological parameters (growth characteristics; water status) of spring wheat (Triticum aestivum L.) was studied at low concentrations (10−6 and 10−9 g/L) under chloride salinity conditions. The plants were grown under laboratory conditions in a CLF PlantClimatics chamber, in which untreated and chemically treated spring wheat seeds were evaluated for changes in morphological and physiological parameters under salt stress conditions (150 mM NaCl). The analysis of obtained data revealed that protatranes have a positive effect on the morphometric parameters and water status of plants under chloride salinity conditions. Thus, the examined substances decrease the inhibition of growth processes under chloride salinity conditions. The treatment of seeds with the studied substances increases the tissue water content while decreasing the osmotic potential drop in leaves and roots. Irrespective of the mix ratio, protatranes help to improve the plant water status and mitigate the negative effects of chloride salinity on plant growth.","PeriodicalId":20601,"journal":{"name":"PROCEEDINGS OF UNIVERSITIES APPLIED CHEMISTRY AND BIOTECHNOLOGY","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91204353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-09DOI: 10.21285/2227-2925-2022-12-3-462-470
D. Batkhishig, E. Shagjjav, S. Batbileg, A. Ankhtuya, B. Purevsuren
The main purpose of this study is to investigate the thermal stability and the mechanism of thermal decomposition of Mogoin gol coal, the possibility of liquefaction by pyrolysis and thermolysis, and the possibility of enriching by heavy liquids to reduce the mineral content of coal and improve its quality. Under this purpose, the Mogoin gol coal was characterized by proximate and ultimate analysis, thermogravimetry, and investigated its thermal decomposition (thermolysis and pyrolysis). Thermogravimetric analysis was performed using Japanese HITACHI TG/DTA7300 instrument and pyrolysis investigation was carried out at different heating temperatures 200–700 °C with constant heating rate 20 °C/min for 80 min. On the basis of proximate and elemental analysis results, it has been indicated that the Mogoin gol coal is high-rank coking coal. The pyrolysis of Mogoin gol coal was studied by SNOL furnace at different heating temperatures and obtained from pyrolysis products such as hard residue, tar, pyrolytic water, and gas. From pyrolysis, the yield of pyrolysis tar (6.28 %) was highest at 700 °C. The experiment of thermal decomposition (thermolysis) was carried out in air closed autoclave at 350–450 °C and using hydrogen donor solvent (tetraline) with different mass ratios of coal and solvent (1:1.75; 1:1.5). In the thermolysis experiment, the yield of liquid product is highest with the coal-solvent ratio of 1: 1.5 at 450 °C.
{"title":"Study on thermal decomposition and enrichment quality of coal from Mogoin gol deposit in Mongolia","authors":"D. Batkhishig, E. Shagjjav, S. Batbileg, A. Ankhtuya, B. Purevsuren","doi":"10.21285/2227-2925-2022-12-3-462-470","DOIUrl":"https://doi.org/10.21285/2227-2925-2022-12-3-462-470","url":null,"abstract":"The main purpose of this study is to investigate the thermal stability and the mechanism of thermal decomposition of Mogoin gol coal, the possibility of liquefaction by pyrolysis and thermolysis, and the possibility of enriching by heavy liquids to reduce the mineral content of coal and improve its quality. Under this purpose, the Mogoin gol coal was characterized by proximate and ultimate analysis, thermogravimetry, and investigated its thermal decomposition (thermolysis and pyrolysis). Thermogravimetric analysis was performed using Japanese HITACHI TG/DTA7300 instrument and pyrolysis investigation was carried out at different heating temperatures 200–700 °C with constant heating rate 20 °C/min for 80 min. On the basis of proximate and elemental analysis results, it has been indicated that the Mogoin gol coal is high-rank coking coal. The pyrolysis of Mogoin gol coal was studied by SNOL furnace at different heating temperatures and obtained from pyrolysis products such as hard residue, tar, pyrolytic water, and gas. From pyrolysis, the yield of pyrolysis tar (6.28 %) was highest at 700 °C. The experiment of thermal decomposition (thermolysis) was carried out in air closed autoclave at 350–450 °C and using hydrogen donor solvent (tetraline) with different mass ratios of coal and solvent (1:1.75; 1:1.5). In the thermolysis experiment, the yield of liquid product is highest with the coal-solvent ratio of 1: 1.5 at 450 °C.","PeriodicalId":20601,"journal":{"name":"PROCEEDINGS OF UNIVERSITIES APPLIED CHEMISTRY AND BIOTECHNOLOGY","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83745663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-09DOI: 10.21285/2227-2925-2022-12-3-479-484
I. Zubkov, Y. Bukin, P. Sorokoumov, S. M. Shishlyannikov
Biosynthetically-produced Pseudomonas poly-3-hydroxyalkanoates (PHAs) are a promising substitute for conventional plastics. Costs involved with the production of PHAs can be reduced by optimizing power consumption, which can be achieved using nutrient media without preliminary steam sterilization. Cultivation of Pseudomonas bacteria resistant to sodium dodecyl sulfate (SDS) on SDS-containing non-sterile media yields a biomass consisting predominantly of a PHA producer. SDS plays the role of an antimicrobial agent that inhibits the growth of foreign microorganisms. In this work, an SDS-resistant culture of Pseudomonas helmanticensis and media containing glycerol and SDS were used. The concentrations of carbon (glycerol) and nitrogen sources were optimized using an experiment performed according to a central composite rotatable design. The concentration of substrate C and the C/N ratio between the glycerol and nitrogen content were varied. The dependence of the degree of substrate conversion in PHA on C and C/N was derived in the R programming environment. The constructed model adequately describes the experimental data at a significance level of 0.05 (adequacy variance of the regression equation 4.1×10-2; R2 =0.98). According to the constructed model, the conversion of glycerol to PHA equals 6.9±0.4%. Under optimized conditions (0.61 g/L nitrogen source; 8.4 g/L glycerol; 96 h), P. helmanticensis converts 7.0% of the substrate to PHA with an average monomer unit length. Using a 16S rRNA metagenomic assay, the proportion of foreign bacteria in P. helmanticensis cultures on non-sterile media containing 0.5 g/L SDS was shown to be 2%.
{"title":"Preparation of polyhydroxyalkanoates using Pseudomonas helmanticensis in non-sterile media containing glycerol and sodium dodecyl sulfate","authors":"I. Zubkov, Y. Bukin, P. Sorokoumov, S. M. Shishlyannikov","doi":"10.21285/2227-2925-2022-12-3-479-484","DOIUrl":"https://doi.org/10.21285/2227-2925-2022-12-3-479-484","url":null,"abstract":"Biosynthetically-produced Pseudomonas poly-3-hydroxyalkanoates (PHAs) are a promising substitute for conventional plastics. Costs involved with the production of PHAs can be reduced by optimizing power consumption, which can be achieved using nutrient media without preliminary steam sterilization. Cultivation of Pseudomonas bacteria resistant to sodium dodecyl sulfate (SDS) on SDS-containing non-sterile media yields a biomass consisting predominantly of a PHA producer. SDS plays the role of an antimicrobial agent that inhibits the growth of foreign microorganisms. In this work, an SDS-resistant culture of Pseudomonas helmanticensis and media containing glycerol and SDS were used. The concentrations of carbon (glycerol) and nitrogen sources were optimized using an experiment performed according to a central composite rotatable design. The concentration of substrate C and the C/N ratio between the glycerol and nitrogen content were varied. The dependence of the degree of substrate conversion in PHA on C and C/N was derived in the R programming environment. The constructed model adequately describes the experimental data at a significance level of 0.05 (adequacy variance of the regression equation 4.1×10-2; R2 =0.98). According to the constructed model, the conversion of glycerol to PHA equals 6.9±0.4%. Under optimized conditions (0.61 g/L nitrogen source; 8.4 g/L glycerol; 96 h), P. helmanticensis converts 7.0% of the substrate to PHA with an average monomer unit length. Using a 16S rRNA metagenomic assay, the proportion of foreign bacteria in P. helmanticensis cultures on non-sterile media containing 0.5 g/L SDS was shown to be 2%.","PeriodicalId":20601,"journal":{"name":"PROCEEDINGS OF UNIVERSITIES APPLIED CHEMISTRY AND BIOTECHNOLOGY","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79183646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-09DOI: 10.21285/2227-2925-2022-12-3-455-461
S. G. Guliyeva, I. Mamedov
The chemical stability of fuels is one of the key factors in ensuring the proper operation of combustion engines. Progressive destruction of components of diesel-biodiesel fuels during storage and transportation can adversely affect their physical and chemical parameters. Besides, the destruction of petroleum products under sunlight and the formation of toxic compounds have ecological importance. The purpose of the presented work is to investigate the influence of UV irradiation (λ = 300–450 nm) on the chemical content of petroleum diesel and B5, B10, B20, B50, and B100 fuel blends for the 24 h. As biodiesel, the product of transesterification of non-edible Alhagi oil with methanol was used. Chemical changes after irradiation were controlled by the BRUKER FT NMR spectrometer. The relationship between changes in the chemical composition and important physicochemical parameters (density, viscosity, flash point, and cetane index), before and after photochemical destructions was discussed. Based on the obtained results, it was determined that the B20 fuel mixture has more chemical stability after UV irradiation than conventional diesel and other diesel-biodiesel mixtures.
{"title":"UV irradiation testing of biodiesel from the Alhagi oil and diesel-biodiesel mixtures","authors":"S. G. Guliyeva, I. Mamedov","doi":"10.21285/2227-2925-2022-12-3-455-461","DOIUrl":"https://doi.org/10.21285/2227-2925-2022-12-3-455-461","url":null,"abstract":"The chemical stability of fuels is one of the key factors in ensuring the proper operation of combustion engines. Progressive destruction of components of diesel-biodiesel fuels during storage and transportation can adversely affect their physical and chemical parameters. Besides, the destruction of petroleum products under sunlight and the formation of toxic compounds have ecological importance. The purpose of the presented work is to investigate the influence of UV irradiation (λ = 300–450 nm) on the chemical content of petroleum diesel and B5, B10, B20, B50, and B100 fuel blends for the 24 h. As biodiesel, the product of transesterification of non-edible Alhagi oil with methanol was used. Chemical changes after irradiation were controlled by the BRUKER FT NMR spectrometer. The relationship between changes in the chemical composition and important physicochemical parameters (density, viscosity, flash point, and cetane index), before and after photochemical destructions was discussed. Based on the obtained results, it was determined that the B20 fuel mixture has more chemical stability after UV irradiation than conventional diesel and other diesel-biodiesel mixtures.","PeriodicalId":20601,"journal":{"name":"PROCEEDINGS OF UNIVERSITIES APPLIED CHEMISTRY AND BIOTECHNOLOGY","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81270136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-07DOI: 10.21285/2227-2925-2022-12-3-424-437
L. Maksimova, T. N. Shafikova
It is widely believed that phthalates are xenobiotic pollutants whose prevalence in the environment is associated with their facilitated diffusion from plastic materials. Studies into the effect of synthetic phthalates on living organisms revealed their extremely negative action on the metabolism of animals and humans. The acting mechanism of these compounds is realised through a ligand-receptor pathway. Along with dioxins, polychlorinated biphenyls and similar compounds, phthalates are classified as endocrine disrupters. However, at present, sufficient evidence has been accumulated confirming the natural origin of phthalates. Thus, phthalates were de novo biosynthesised from labelled precursors in an algae culture. These compounds were detected in closed experimental systems, including cell cultures of highest plants, as well as those isolated from a number of bacterial, fungi, lowest and highest plant forms located far from the sources of technogenic pollution. The concept of phthalate biogenesis assumes the action of these compounds on living systems. Phthalates exhibit bactericidal and fungicidal action and compose allelopathic exudates, suppressing the growth of competing plant forms. Phthalates possess insecticidal and repellent properties. An analogy can be traced between the action of phthalates and endocrine disrupters of another chemical category, namely phytoestrogens, which regulate herbivorous mammal populations. A hypothesis is proposed about the biological role of endogenous plant phthalates representing secondary metabolic compounds. Exhibiting predominantly a shielding function, these compounds participate in the network of interactions between plants, animals, fungi and microorganisms. It should be noted that synthetic and endogenous phthalates are characterised by essential stereochemical differences, which can explain their different action on living organisms.
{"title":"Endogenous phthalates as a prospective regulator of interspecific relations in a biocoenosis","authors":"L. Maksimova, T. N. Shafikova","doi":"10.21285/2227-2925-2022-12-3-424-437","DOIUrl":"https://doi.org/10.21285/2227-2925-2022-12-3-424-437","url":null,"abstract":"It is widely believed that phthalates are xenobiotic pollutants whose prevalence in the environment is associated with their facilitated diffusion from plastic materials. Studies into the effect of synthetic phthalates on living organisms revealed their extremely negative action on the metabolism of animals and humans. The acting mechanism of these compounds is realised through a ligand-receptor pathway. Along with dioxins, polychlorinated biphenyls and similar compounds, phthalates are classified as endocrine disrupters. However, at present, sufficient evidence has been accumulated confirming the natural origin of phthalates. Thus, phthalates were de novo biosynthesised from labelled precursors in an algae culture. These compounds were detected in closed experimental systems, including cell cultures of highest plants, as well as those isolated from a number of bacterial, fungi, lowest and highest plant forms located far from the sources of technogenic pollution. The concept of phthalate biogenesis assumes the action of these compounds on living systems. Phthalates exhibit bactericidal and fungicidal action and compose allelopathic exudates, suppressing the growth of competing plant forms. Phthalates possess insecticidal and repellent properties. An analogy can be traced between the action of phthalates and endocrine disrupters of another chemical category, namely phytoestrogens, which regulate herbivorous mammal populations. A hypothesis is proposed about the biological role of endogenous plant phthalates representing secondary metabolic compounds. Exhibiting predominantly a shielding function, these compounds participate in the network of interactions between plants, animals, fungi and microorganisms. It should be noted that synthetic and endogenous phthalates are characterised by essential stereochemical differences, which can explain their different action on living organisms.","PeriodicalId":20601,"journal":{"name":"PROCEEDINGS OF UNIVERSITIES APPLIED CHEMISTRY AND BIOTECHNOLOGY","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75703106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-07DOI: 10.21285/2227-2925-2022-12-3-417-423
V. A. Pisarevskaia, A. S. Zhuravliova, M. V. Minich, N. Behbudzada, A. A. Shagaev, N. S. Markvichev
The paper examines the growth of Trichoderma spp. strains and their interaction at different temperatures. Trichoderma spp. is a genus of microscopic ascomycetes; these fungi belong to different ecosystems and are found in soil (rhizosphere). The study aims to analyze and compare the characteristics pertaining to the growth of Trichoderma species and the interaction between them. The experiments used the following media: a Czapek medium and a medium simulating plant root exudates (Cucumis sativus). The growth rate of Trichoderma spp. strains was determined at different temperatures. The use of a medium containing plant exudate models provided a different growth rate as compared to that obtained when using a rich growth medium; some variations in the macromorphology of colonies were also observed. The growth of Trichoderma longibrachiatum F2124 and Trichoderma viride F2001 strains was detected at 9 °С on the Czapek medium, while only the Trichoderma longibrachiatum F2124 strain was observed to grow on the medium simulating exudates. A significant growth inhibition was noted at 40 °С for all strains, except for Trichoderma longibrachiatum species. No colony growth was observed at 50 °С. All the strains grew within the temperature range of 12 to 28 °С. It was assumed that Trichoderma species growing in various media may interact differently with each other. Interaction between the three strains of Trichoderma spp. was examined via the surface culture method under different temperature conditions. The study found no significant differences in the interaction between the Trichoderma species.
{"title":"Trichoderma spp. strains: growth and interaction at different temperatures","authors":"V. A. Pisarevskaia, A. S. Zhuravliova, M. V. Minich, N. Behbudzada, A. A. Shagaev, N. S. Markvichev","doi":"10.21285/2227-2925-2022-12-3-417-423","DOIUrl":"https://doi.org/10.21285/2227-2925-2022-12-3-417-423","url":null,"abstract":"The paper examines the growth of Trichoderma spp. strains and their interaction at different temperatures. Trichoderma spp. is a genus of microscopic ascomycetes; these fungi belong to different ecosystems and are found in soil (rhizosphere). The study aims to analyze and compare the characteristics pertaining to the growth of Trichoderma species and the interaction between them. The experiments used the following media: a Czapek medium and a medium simulating plant root exudates (Cucumis sativus). The growth rate of Trichoderma spp. strains was determined at different temperatures. The use of a medium containing plant exudate models provided a different growth rate as compared to that obtained when using a rich growth medium; some variations in the macromorphology of colonies were also observed. The growth of Trichoderma longibrachiatum F2124 and Trichoderma viride F2001 strains was detected at 9 °С on the Czapek medium, while only the Trichoderma longibrachiatum F2124 strain was observed to grow on the medium simulating exudates. A significant growth inhibition was noted at 40 °С for all strains, except for Trichoderma longibrachiatum species. No colony growth was observed at 50 °С. All the strains grew within the temperature range of 12 to 28 °С. It was assumed that Trichoderma species growing in various media may interact differently with each other. Interaction between the three strains of Trichoderma spp. was examined via the surface culture method under different temperature conditions. The study found no significant differences in the interaction between the Trichoderma species.","PeriodicalId":20601,"journal":{"name":"PROCEEDINGS OF UNIVERSITIES APPLIED CHEMISTRY AND BIOTECHNOLOGY","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72739261","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-07DOI: 10.21285/2227-2925-2022-12-3-447-454
E. Gotlib, E. Perushkina, R. S. Ntsoumou, E. Yamaleeva
Due to the microbiological resistance of epoxy resins, their disposal after the completion of their lifecycle is a pressing issue. In this respect, the use of biodegradable rice and buckwheat husk derivatives as fillers may improve the service properties of epoxy materials. The results indicate that rice and buckwheat husks, as well as their ashes, can be used by soil microorganisms as a substrate. Compared to buckwheat husks, rice husks increase the biological activity of soil microbiota to a much greater extent. However, compared to rice husks, an increase in the temperature of obtaining rice husk ash leads to a decrease in its use by soil microorganisms as a substrate. This is associated with a decreased content of the X-ray amorphous phase and an increased amount of crystalline minerals in the composition of rice husk ash. At the same time, regardless of the temperature of its production, buckwheat husk ash outperforms buckwheat husks in terms of activated soil respiration, which indicates the possibility of microbiological disposal of buckwheat husk ash during its incubation in a soil. Epoxy materials, both unfilled and filled with rice and buckwheat husk ash, are not used by soil microorganisms as a substrate. At the same time, the filling of epoxy materials with rice husks leads to an improvement in their biodegradability. The biodegradation degree of rice and buckwheat husks, as well as their ashes, determines the effect of these fillers on soil respiration in the presence of epoxy materials.
{"title":"Effects of rice and buckwheat husk ash on the biodegradability of epoxy materials","authors":"E. Gotlib, E. Perushkina, R. S. Ntsoumou, E. Yamaleeva","doi":"10.21285/2227-2925-2022-12-3-447-454","DOIUrl":"https://doi.org/10.21285/2227-2925-2022-12-3-447-454","url":null,"abstract":"Due to the microbiological resistance of epoxy resins, their disposal after the completion of their lifecycle is a pressing issue. In this respect, the use of biodegradable rice and buckwheat husk derivatives as fillers may improve the service properties of epoxy materials. The results indicate that rice and buckwheat husks, as well as their ashes, can be used by soil microorganisms as a substrate. Compared to buckwheat husks, rice husks increase the biological activity of soil microbiota to a much greater extent. However, compared to rice husks, an increase in the temperature of obtaining rice husk ash leads to a decrease in its use by soil microorganisms as a substrate. This is associated with a decreased content of the X-ray amorphous phase and an increased amount of crystalline minerals in the composition of rice husk ash. At the same time, regardless of the temperature of its production, buckwheat husk ash outperforms buckwheat husks in terms of activated soil respiration, which indicates the possibility of microbiological disposal of buckwheat husk ash during its incubation in a soil. Epoxy materials, both unfilled and filled with rice and buckwheat husk ash, are not used by soil microorganisms as a substrate. At the same time, the filling of epoxy materials with rice husks leads to an improvement in their biodegradability. The biodegradation degree of rice and buckwheat husks, as well as their ashes, determines the effect of these fillers on soil respiration in the presence of epoxy materials.","PeriodicalId":20601,"journal":{"name":"PROCEEDINGS OF UNIVERSITIES APPLIED CHEMISTRY AND BIOTECHNOLOGY","volume":"546 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85661236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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