Dominant Amino Acids Research Articles

Milk fermentation affects amino acid and fatty acid profile of mare milk from Polish Coldblood mares

The aim of this work was to demonstrate the influence of mare milk fermentation type on the amino acid profile, especially the content of tryptophan, water-soluble vitamins and magnesium. Additionally, the atherogenic, thrombogenic and hypercholesterolaemic fatty acid index was analysed. The dominant amino acids of mare milk were glutamic acid, leucine, lysine, and aspartic acid. Fermentation of mares' milk did not affect the riboflavin, cobalamin, and magnesium content. The type of lactic acid bacteria used had no effect on the free tryptophan content of fermented milk. The free tryptophan content of fermented mares' milk was 0.062 mg 100 g−1 (Δ22% compared with unfermented milk). The sum of saturated fatty acid concentration was lower in fermented than in the unfermented mares' milk. Atherogenic index was lower in mare milk than in fermented mares’ milk. The values of fatty acids with a hypocholesterolaemic effect and hypercholesterolaemic fatty acids decreased in fermented milk.

Beyond the farm: Making edible protein from CO2 via hybrid bioinorganic electrosynthesis

Beyond the farm: Making edible protein from CO2 via hybrid bioinorganic electrosynthesis

Examining the amino acid composition, secondary structure, and physicochemical and functional properties of proteins isolated from local lentil landraces of Anatolia

AbstractBackground and objectivesProviding information on protein structure and functionality is essential for evaluating the potential of specific agricultural commodities to be utilized as plant‐based protein sources. Amino acid composition, secondary structure, surface charge, thermal, and functional properties of proteins isolated from five local lentil landraces were investigated. Secondary objective of the study was to investigate if a relationship exists between the amino acid composition and the physicochemical or functional properties of the isolates.FindingsAspartic acid and glutamic acid were found to be the dominant amino acids in the isolates while they were poor in methionine. Denaturation temperatures of isolates ranged between 96–108°C and their secondary structure mainly consisted of β‐sheet. Emulsion capacity, emulsifying activity (EAI), and emulsion stability indices (ESI) of isolates were found to be between 403.8–468.2 g oil/g protein, 18.8–24.2 m2/g, and 43.4–125.5 min, respectively. Foaming capacity of the isolates changed between 71% and 91% whereas their least gelation concentration varied between 110 and 150 g/L.ConclusionsYusufhan isolate which had relatively higher acidic amino acid content showed the highest net charge and solubility at acidic pH. Tigris isolate which had higher hydrophobic amino acid content compared to the other isolates showed relatively high thermal stability, EAI and ESI.Significance and noveltyFindings of the study make a contribution toward the potential use of local lentil landraces as sources for extracting protein‐based ingredients.

Chemical Composition of Apples Cultivated in Norway

The composition of apples varies with both cultivar and horticultural practice. Knowledge about the chemical composition of different cultivars in particular sugars, organic acids, nitrogen compounds and polyphenols is essential, since they are directly related to the progress of fermentation monitoring and the organoleptic qualities of produced ciders. Fifteen apple cultivars grown in two locations in Norway were investigated for their chemical composition, including polyphenol profiles. The nitrogen content varied from 43.2 to 171.4 mg N/L between the cultivars, and the sum of free amino acids varied from 42.4 to 924.5 mg/kg. Asparagine, aspartic acid and glutamic acid were the dominating amino acids. Flavanols, consisting of catechins and procyanidins, were the dominating polyphenols, followed by hydroxycinnamic acids. The cultivar Bramley Seedling was highest in the sum of polyphenols by HPLC (1838 mg/L) and relatively low in nitrogen content (75 mg N/L). Summerred was lowest in the sum of polyphenols (87 mg/L) and highest in nitrogen (171.4 mg N/L). Sugar content, measured as density in the juice, varied between 1034 and 1060 g/L. Using cider categorization of apples, ’Bramley Seedling’ would be defined as sharp, while the others are sweet cultivars.

AGE DYNAMICS OF FREE AMINO ACIDS IN THE TISSUES OF THE MEDICINAL LEECH Hirudo verbana Carena, 1820 UNDER ARTIFICIAL REPRODUCTION IN AQUACULTURE

Medicinal leeches (Hirudo verbana Carena, 1820) used in veterinary medicine, human medicine and pharmacology, are currently bred artificially at bio-factories. The technology of leech culture as a component of aquaculture biotechnics is based on the method of accelerated growth of leeches due to intensive feeding, which allows you to get high-quality products in a fairly short time (8-10 months). Nevertheless, the problem of assessing the physiological status of raised individuals upon artificial reproduction remains not fully addressed. The findings we present herein for the first time allow us to suggest that the age-specific amino acid composition of tissues can be used to assess the physiological state and well-being of medicinal leeches in nature and in aquaculture. The aim of the work is to study the age-dependent content of the free amino acids in the tissues of medicinal leeches artificially bred in aquaculture. Studies were conducted in 2012 on the leech (Hirudo verbana Carena, 1820) individuals without signs of diseases which were purchased at the biofactory International Center for Medicinal Leeches (Moscow Province, p. Udelnaya). Leeches were kept in the laboratory in glass vessels with dechlorinated water at 20-22 oC and fed once a month with fresh bovine blood from healthy animals. The experimental specimens of H. verbana was: 5 days (newborn filaments, 0+), 1, 3, 5, 7 and 9 months old, with an average body weight of 0.029, 0.09, 0.25, 0.61, 1.33 and 1.81 g, respectively. Newborn individuals served as a control. The concentration of free amino acids (AA) in the skin and muscle tissue was determined on the analyzer AAA-339M (Mikrotechna, Czech Republic). A total of 105 leech specimens were used, 30 bioassays were prepared, and 660 element determinations were performed. The amino acid composition of the tissues of medicinal leeches H. verbana was represented by 23 AA and their derivatives. The dominant AA with an antioxidant orientation, regardless of age, were glutamine and glutamic acid, alanine, valine, leucine, and glycine, the total content of which was 65 % in filaments, and 58 % in 9-month — old individuals of the total fund AA. In the tissues of medicinal leeches, as well as in warm-blooded animals, the full composition of essential amino acids (EAA) was revealed: threonine, valine, lysine, leucine, isoleucine, histidine, arginine, methionine, phenylalanine, tryptophan. With age, the total concentrations of free amino acids decreased (r = -0.98 at p = 0.000), due to a sharp decrease in the content of arginine (24.0-fold), proline (13.4- fold), isoleucine (12.2- fold), glycine (8.5- fold), lysine (6.8- fold), histidine (6.6-fold), leucine (5.2-fold), ornithine (4.0- fold), glutamic acid and glutamine (3.8-fold), and alanine (2.9-fold). At the age of 5, 7 and 9 months, leeches had a trace content of secondary metabolites: taurine, citrulline and tryptophan (p < 0.001). However, the amino acid balance of nitrogen and protein metabolism was not disturbed, since the ratio of essential / non-essential AА did not change significantly and was 0.60 in newborn filaments, 0.73 — in 9-month-old leeches. It was found that the growth and development of H. verbana was accompanied by a significant decrease in the indicator of maturity (glycine/alanine) from 0.75 (newborn filaments) to 0.25 (9 months). The information available in the literature and the data of our research allow us to put forward the concept of using functional amino acids as biomarkers in the development of the scientific bases of technologies for the industrial breeding of these amphibionts.

ВОЗРАСТНАЯ ДИНАМИКА СВОБОДНЫХ АМИНОКИСЛОТ В ТКАНЯХ МЕДИЦИНСКОЙ ПИЯВКИ (Hirudo verbana Carena, 1820) ПРИ ИСКУССТВЕННОМ ВОСПРОИЗВОДСТВЕ В АКВА-КУЛЬТУРЕ

Medicinal leeches (Hirudo verbana Carena, 1820) used in veterinary medicine, human medicine and pharmacology, are currently bred artificially at bio-factories. The technology of leech culture as a component of aquaculture biotechnics is based on the method of accelerated growth of leeches due to intensive feeding, which allows you to get high-quality products in a fairly short time (8-10 months). Nevertheless, the problem of assessing the physiological status of raised individuals upon artificial reproduction remains not fully addressed. The findings we present herein for the first time allow us to suggest that the age-specific amino acid composition of tissues can be used to assess the physiological state and well-being of medicinal leeches in nature and in aquaculture. The aim of the work is to study the age-dependent content of the free amino acids in the tissues of medicinal leeches artificially bred in aquaculture. Studies were conducted in 2012 on the leech (Hirudo verbana Carena, 1820) individuals without signs of diseases which were purchased at the biofactory International Center for Medicinal Leeches (Moscow Province, p. Udelnaya). Leeches were kept in the laboratory in glass vessels with dechlorinated water at 20-22 oC and fed once a month with fresh bovine blood from healthy animals. The experimental specimens of H. verbana was: 5 days (newborn filaments, 0+), 1, 3, 5, 7 and 9 months old, with an average body weight of 0.029, 0.09, 0.25, 0.61, 1.33 and 1.81 g, respectively. Newborn individuals served as a control. The concentration of free amino acids (AA) in the skin and muscle tissue was determined on the analyzer AAA-339M (Mikrotechna, Czech Republic). A total of 105 leech specimens were used, 30 bioassays were prepared, and 660 element determinations were performed. The amino acid composition of the tissues of medicinal leeches H. verbana was represented by 23 AA and their derivatives. The dominant AA with an antioxidant orientation, regardless of age, were glutamine and glutamic acid, alanine, valine, leucine, and glycine, the total content of which was 65 % in filaments, and 58 % in 9-month — old individuals of the total fund AA. In the tissues of medicinal leeches, as well as in warm-blooded animals, the full composition of essential amino acids (EAA) was revealed: threonine, valine, lysine, leucine, isoleucine, histidine, arginine, methionine, phenylalanine, tryptophan. With age, the total concentrations of free amino acids decreased (r = -0.98 at p = 0.000), due to a sharp decrease in the content of arginine (24.0-fold), proline (13.4- fold), isoleucine (12.2- fold), glycine (8.5- fold), lysine (6.8- fold), histidine (6.6-fold), leucine (5.2-fold), ornithine (4.0- fold), glutamic acid and glutamine (3.8-fold), and alanine (2.9-fold). At the age of 5, 7 and 9 months, leeches had a trace content of secondary metabolites: taurine, citrulline and tryptophan (p < 0.001). However, the amino acid balance of nitrogen and protein metabolism was not disturbed, since the ratio of essential / non-essential AА did not change significantly and was 0.60 in newborn filaments, 0.73 — in 9-month-old leeches. It was found that the growth and development of H. verbana was accompanied by a significant decrease in the indicator of maturity (glycine/alanine) from 0.75 (newborn filaments) to 0.25 (9 months). The information available in the literature and the data of our research allow us to put forward the concept of using functional amino acids as biomarkers in the development of the scientific bases of technologies for the industrial breeding of these amphibionts.

Studies on the chemical composition of fruits and seeds of Pseudocydonia sinensis (Thouin) C.K. Schneid

Pseudocydonia sinensis (Thouin) C. K. Schneid. less known plant species in the Ukraine conditions, but the fruits were widely used in traditional Chinese medicine for the treatment of asthma, colds, sore throat, mastitis, rheumatoid arthritis, and tuberculosis. The content of protein, ash, and lipids in the seeds was found to be greater than in the pulp and peel. Monosaccharide analysis of neutral carbohydrate part showed the presence of two main sugars fructose and sucrose in the seeds, pulp, and peel. There is a higher beta-carotene content in the rind of the fruit than in the seeds and pulp. The total amount of fatty acids varied from sample to sample and contained mainly oleic acid, palmitic acid, linolenic acid, and linoleic acid. Linoleic acid in the seeds was 48.02% of total fatty acids, slightly less in the rind 42.70%. Palmitic acid, oleic acid, and linoleic acid in the pulp samples were 45.38, 21.32, and 14.93%, respectively. The total amount of amino acids found in the seeds was 105.0 g.kg-1 DM, including total essential amino acids (32.70 g.kg-1 DM). Glutamic acid was found in seeds to be the dominant free amino acid followed by aspartic acid and arginine in the seed. In our study, the antioxidant activity carried out by the DPPH method and measured by molybdenum reducing antioxidant power of peel, pulp and seeds were 9.41, 7.08, 6.21, and 158.81, 92.83, 78.58 mg TEAC.g-1 DM, respectively. Micro and macronutrients and amino acids predominated in the seeds, total fatty acids predominated in the pulp. The highest content of bioactive compounds (total polyphenols, flavonoid, and phenolic acid) and antioxidant activity was found in the peel. P. sinensis can be considered as a nourishing fruit with a copious potential with health-promoting roles and medicinal properties.

A Single Point Mutation, Asn16→Lys, Dictates the Temperature-Sensitivity of the Reovirus tsG453 Mutant

Studies of conditionally lethal mutants can help delineate the structure-function relationships of biomolecules. Temperature-sensitive (ts) mammalian reovirus (MRV) mutants were isolated and characterized many years ago. Two of the most well-defined MRV ts mutants are tsC447, which contains mutations in the S2 gene encoding viral core protein σ2, and tsG453, which contains mutations in the S4 gene encoding major outer-capsid protein σ3. Because many MRV ts mutants, including both tsC447 and tsG453, encode multiple amino acid substitutions, the specific amino acid substitutions responsible for the ts phenotype are unknown. We used reverse genetics to recover recombinant reoviruses containing the single amino acid polymorphisms present in ts mutants tsC447 and tsG453 and assessed the recombinant viruses for temperature-sensitivity by efficiency-of-plating assays. Of the three amino acid substitutions in the tsG453 S4 gene, Asn16-Lys was solely responsible for the tsG453 ts phenotype. Additionally, the mutant tsC447 Ala188-Val mutation did not induce a temperature-sensitive phenotype. This study is the first to employ reverse genetics to identify the dominant amino acid substitutions responsible for the tsC447 and tsG453 mutations and relate these substitutions to respective phenotypes. Further studies of other MRV ts mutants are warranted to define the sequence polymorphisms responsible for temperature sensitivity.

A new approach to recycling cephalosporin fermentation residue into plant biostimulants

Cephalosporin fermentation residue (CFR), a byproduct of the pharmaceutical industry, mainly contains the mycelial biomass and unutilized culture medium, which can be reused as a high-quality protein source. This study first reports the recycling CFR into plant biostimulants using partial acid hydrolysis. Temperature, reaction time and ratio of hydrochloric acid/dry matter (H/S) were optimized for yielding both free amino acid and low molecular weight fraction based on response surface methodology. The crude protein concentration of CFR is 55%, with glutamic acid being the dominant amino acid (12.5%). Two favorable hydrolysis conditions were obtained: (1) 140 °C, 10.7 h, 17 H/S for maximizing the amino acid yield of 45.5 g/100 g CFR dw and (2) 100 °C, 10.7 h, 19 H/S for maximizing the low molecular weight fraction of 28.2%. The CFR-derived biostimulants obtained from two optimum conditions possessed two biostimulant modes of action: plant growth promotors/inhibitors and stress alleviators. However, they showed the differences in aminograms and profiles of low molecular weight compounds. Neither residual cephalosporin C nor its byproduct was detected in the CFR-derived biostimulants, suggesting that partial acid hydrolysis appears capable of recycling CFR into plant biostimulant safely.

Chemical, Nutritional, Microbial, and Sensory Characteristic of Fish Sauce Suragh from Hormozgan, Iran

ABSTRACT This study was undertaken to investigate the chemical, nutritional, microbial, and sensory properties of fish sauce Suragh prepared by fermentation using Rainbow sardine (Dussumieria acuta) with red soil (3%) at different salt concentrations (20%, 25%, 30%, and 35%). The fermentation process was carried out for 180 days at room temperature. The pH value and total volatile base-nitrogen (TVB-N) content of sauces range from 7.04 to 5.47 and 288.43–70.83 mg/100 g with the increasing level of salt concentration, respectively. Amino acid analyses revealed that lysine and leucine are the major essential amino acids, while glutamine/glutamic acid and alanine are the dominant nonessential amino acids in fish sauces. The fatty acid profile showed decreasing contents of polyunsaturated fatty acids (PUFA) and high-unsaturated fatty acid (HUFA) in fish sauce samples when the salt level increased. The total viable count (TVC), halophilic bacteria, yeast, and mold of all samples decreased to less than 1 log CFU/g after fermentation. The sensory evaluation showed that the sample with 35% salt added had the highest overall acceptance score. Based on the chemical, nutritional, microbial, and sensory evaluation, high-quality fish sauce Suragh could be produced using 35% salt concentration, and it could be considered as a healthy condiment for human consumption.

Analysis of proteolytic processing sites in potyvirus polyproteins revealed differential amino acid preferences of NIa-Pro protease in each of seven cleavage sites.

Potyviruses encode a large polyprotein that undergoes proteolytic processing, producing 10 mature proteins: P1, HC-Pro, P3, 6K1, CI, 6K2, VPg, NIa-Pro, NIb-RdRp, and CP. While P1/HC-Pro and HC-Pro/P3 junctions are cleaved by P1 and HC-Pro, respectively, the remaining seven are processed by NIa-Pro. In this study, we analyzed 135 polyprotein sequences from approved potyvirus species and deduced the consensus amino acid residues at five positions (from −4 to +1, where a protease cleaves between −1 and +1) in each of nine cleavage sites. In general, the newly deduced consensus sequences were consistent with the previous ones. However, seven NIa-Pro cleavage sites showed distinct amino acid preferences despite being processed by the same protease. At position −2, histidine was the dominant amino acid residue in most cleavage sites (57.8–60.7% of analyzed sequences), except for the NIa-Pro/NIb-RdRp junction where it was absent. At position −1, glutamine was highly dominant in most sites (88.2–97.8%), except for the VPg/NIa-Pro junction where glutamic acid was found in all the analyzed proteins (100%). At position +1, serine was the most abundant residue (47.4–86.7%) in five out of seven sites, while alanine (52.6%) and glycine (82.2%) were the most abundant in the P3/6K1 and 6K2/VPg junctions, respectively. These findings suggest that each NIa-Pro cleavage site is finely tuned for differential characteristics of proteolytic reactions. The newly deduced consensus sequences may be useful resources for the development of models and methods to accurately predict potyvirus polyprotein processing sites.

Novel insight into physicochemical and flavor formation in naturally fermented tilapia sausage based on microbial metabolic network

The quality and flavor formation in fermented fish sausages are based on the complex metabolism of microbial community. In this study, the dynamic changes of physicochemical characteristics, volatile compounds, and microbial communities in the naturally fermented tilapia sausage were studied during the fermentation process. The main physical indexes (gel strength, whiteness, and hardness), dominant flavor free amino acids (glycine, alanine, and glutamic acid) and characteristic volatile flavor compounds (hexanal, heptanal, octanal, benzaldehyde, (E)-2-octenal, 4-ethylbenzaldehyde, (E)-2-heptenal, (E,E)-2,4-decadienal, 1-octen-3-ol, 2-pentylfuran, and 2-ethyl-furan) were significantly enhanced after fermentation, and were positively correlated with Lactococcus, Pediococcus, Enterococcus, and Lactobacillus. The microbial metabolic network showed that Lactococcus, Pediococcus, and Enterococcus played a significant role in the formation of physicochemical and flavor characteristics, while the accumulation of biogenic amines might result from the metabolism of Enterococcus, Enterobacter, and Citrobacter. Isolation of lactic acid bacteria in Lactococcus and Pediococcus might be suitable to improve the fermented tilapia sausage. Microbial metabolic network has revealed the physicochemical and flavor formation of tilapia sausage and can provide guidance for future research on screening of starters.

Synthesis of Organic Matter in Aqueous Environments Simulating Small Bodies in the Solar System and the Effects of Minerals on Amino Acid Formation

The extraterrestrial delivery of organics to primitive Earth has been supported by many laboratory and space experiments. Minerals played an important role in the evolution of meteoritic organic matter. In this study, we simulated aqueous alteration in small bodies by using a solution mixture of H2CO and NH3 in the presence of water at 150 °C under different heating durations, which produced amino acids after acid hydrolysis. Moreover, minerals were added to the previous mixture to examine their catalyzing/inhibiting impact on amino acid formation. Without minerals, glycine was the dominant amino acid obtained at 1 d of the heating experiment, while alanine and β-alanine increased significantly and became dominant after 3 to 7 d. Minerals enhanced the yield of amino acids at short heating duration (1 d); however, they induced their decomposition at longer heating duration (7 d). Additionally, montmorillonite enhanced amino acid production at 1 d, while olivine and serpentine enhanced production at 3 d. Molecular weight distribution in the whole of the products obtained by gel chromatography showed that minerals enhanced both decomposition and combination of molecules. Our results indicate that minerals affected the formation of amino acids in aqueous environments in small Solar System bodies and that the amino acids could have different response behaviors according to different minerals.

Phytochemical composition of leaves and stems of Solanum nigrum L. and Solanum dulcamara L. (Solanaceae) from Bulgaria

The objective of this study was the determination of certain phytochemical indices (cellulose, protein, amino acids, ash, minerals) of the leaves and stems of two Solanum species, S. dulcamara L. and S. nigrum L., collected from their natural habitats in Bulgaria. Both species, naturally occurring in many regions of Bulgaria, are important plants in folk medicine and fall under the regulations of the Medicinal Plant Act. The analysis of cellulose, protein and ash content in the dried leaves and stems revealed differences on a plant part basis. Stems contained higher amounts of cellulose (S. dulcamara, 29.4%; S. nigrum, 39.2%) than the leaves (14.9% in both species). The stems of S. nigrum contained nearly twice as much protein than the leaves (15.3% vs 8.1%); the ratio was reversed in S. dulcamara (12.3% vs 21.3%). The dominant macroelements in S. dulcamara were K (25925 and 14514 mg.kg-1, respectively in the leaves and stems), Ca (3588 and 326 mg.kg-1) and Mg (2561 and 308 mg.kg-1). In S. nigrum, the same macrominerals showed relatively less variation on a plant part basis. The dominant microminerals were Fe, Zn and Mn; reasonably, higher concentrations were found in the leaves. The dominant amino acids in S. dulcamara leaves were phenylalanine, glutamine, asparagine, tyrosine, and serine (2.2-2.5 mg.g-1); in the stems-proline (7.3 mg.g-1), alanine (7.2 mg.g-1), asparagine (5.0 mg.g-1), and lysine (4.6 mg.g-1). The dominant amino acid in S. nigrum leaves and stems was asparagine, 5.0 mg.g-1 and 20.6 mg.g-1, respectively. The results supported the assumption that the studied aerial parts contained valuable phytochemicals, which could provide grounds for their practical use in specific areas, such as human and animal nutrition, cosmetics, phytopharmacy or others.

An Identification and Study of Amino Acids of Erigeron annuus Herb

Amino acids in the extract of Erigeron annuus herb were determined using an automatic precolumn derivatization with fluorenylmethyl-chloroformate and reversed-phase liquid chromatography with fluorescence and UV Vis detection. This objective is reached with automatic derivatization using o-phthalaldehyde (OPA) for primary amino acids and 9-Fluorenylmethyl chloroformate (FMOC) for secondary amino acids. Then derivatization integrates into high performance liquid chromatography (HPLC). The applied procedure is fast with easily reproduced results. The insufficient knowledge about amino acids composition of herb of Erigeron annuus is the basis for study. This work reports on content of 16 free and bound amino acids (391.41 μg/mg) in the plant raw material and influence’s evaluation of different extraction types on the amino acid profile. The total content of free amino acids was 4.66 μg/mg; proline prevailed (2.498 μg/mg). The total content of bound amino acids was 386.7 μg/mg; proline (146.8 μg/mg), arginine (67.8 μg/mg), phenylalanine (25.8 μg/mg), asparagine (24.3 μg/mg), histidine (20.4 μg/mg), alanine (18.2 μg/mg), serine (16.6 μg/mg), valine (16.0 μg/mg) were the dominant amino acids. Nine amino acids were classified as essential.

The leaves and stems of Cape gooseberry (Physalis peruviana L.) as an alternative source of bioactive substances

The objective of this work was the investigation of the chemical composition of the leaves and stems of two Cape gooseberry (Physalis peruviana L.) genotypes from Bulgaria (CG-SB and CG-NB), with the view of establishing the presence of certain bioactive substances and the prospects for their use as livestock feed or cosmetic ingredients. The leaves and stems of CG-SB genotype contained 18.63% and 40.26% cellulose, respectively, and 24.83% and 13.73% protein; the respective contents in the leaves and stems of CG-NB genotype were 27.63% and 47.63% cellulose, and 9.36% and 8.07% protein. The dominant amino acids in CG-SB leaves were aspartic acid (32.04 mg.g-1) and lysine (30.54 mg.g-1), and in the stems – proline (46.90 mg.g-1) and phenylalanine (15.42 mg.g-1). The amino acid composition of the leaves of CG-NB genotype was dominated by histidine (24.88 mg.g-1) and proline (21.25 mg.g-1), and that of the stems – by proline (13.38 mg.g-1). The main macro and micro minerals in the leaves and stems of both genotypes were K, Mg and Fe, respectively, but numerical differences were observed on a genotype and plant part basis. The leaves were processed by extraction with n-hexane and the content of volatiles was determined (by GC-MS). A total of 32 components was identified in each of the genotypes. The major volatile in both genotypes was n-pentacosanol, 17.07% in CG-SB and 12.39% in CG-NB; the dominant group of chemicals was that of oxygenated aliphatics, followed by diterpenes. The results from the study provide arguments that the leaves and stems of Cape gooseberry, currently discarded byproducts, could be regarded as alternative sources of bioactive substances.

CONSUMER VALUE OF FRESHWATER FISH JELLIES

Background. In order to form a balanced diet that ensures harmonious deve­lopment of human, prevention of various diseases, especially in conditions of coronavirus infection COVID-19 the recipes for jellied products based on freshwater fish with the addition of plant additives (cranberries, parsley roots, carrots, beets, fresh green and onions, spicy-flavored vegetables (green dill, parsley) and seaweedweredeveloped. The aim of the work is to study the consumer value of jellied fish products with herbal supplements. Materials and methods. The object of research is freshwater fish jellies with the addition of plant additives and seaweed. Jellied fish without vegetable additives was selected as a control sample. The content of moisture, ash, fat, protein, amino acid composition of proteins, fatty acid composition of lipids, mineral composition; the content of vitamins (thiamine, riboflavin, niacin, carotenoids, tocopherols) was studied by conventional methods. Repea­tability of experiments –five times, the relative error did not exceed 5 %. Results. Studies of the chemical composition show that the control sample, in contrast to the studied ones, contains more fat and protein, which is explained by the lack of vegetable raw materials according to the recipe. However, the addition of vegetable raw materials to the latter increases the mineral content by 15–31 %. The content of essential amino acids in the control is 45 % of the total content, and in the test samples – 46 %. The dominant amino acid in the samples is lysine, and the limited ones are valine and isoleucine. The utilitarian coefficient of the amino acid composition of the studied samples (0.61–0.63) indicates a high balance of amino acids relative to the standard. The low coefficient of redundancy (0.21–0.23) and the high coefficient of utilitarianism indicate the maximum degree of assimilation of proteins of jellied fish products by the human body. The content of polyunsaturated fatty acids (PUFA) in the filling products was 26 %. The ratio of PUFA: SFA, C18:2: C18:1 and C18:2: C18:3 is established as rational in jellied fish. The value of the absorption coefficient for the studied samples of jellied products with beets, onions and control is 0.80, and carrots and cranberries – 0.79. The content of thiamine in jellied fish with carrots, onions, beets is 2 times higher than in the control, the content of niacin – 1.2 times, vitamin E – 1.7–1.2 times. The highest content of carotenoids is found in jellied fish with carrots and onions. An increase in the level of Potassium, Calcium, Bromine, Iodine, Iron, Selenium in the experimental filling products compared with the control was determined: Potassium by 45 %,Selenium 5.5–8.0 times, Manganese 1.6 times. Conclusion. The enrichment of fish products with plant components contributes to the expansion of the range of products of high nutritional and biological value with a high degree of satisfaction of the physiological needs of the human body with biolo­gically active substances. Accordingly, the consumption of jellied fish products allows to improve the functional state of the most important systems of the human body, preven­tion of food-dependent diseases, various forms of immunodeficiency, especially in condi­tions of coronavirus infection COVID-19.

Metagenomic and Metatranscriptomic Analyses Revealed Uncultured Bacteroidales Populations as the Dominant Proteolytic Amino Acid Degraders in Anaerobic Digesters.

Current understanding of amino acid (AA) degraders in anaerobic digesters is mainly based on cultured species, whereas microorganisms that play important roles in a complex microbial community remain poorly characterized. This study investigated short-term enrichments degrading single AAs using metagenomics and metatranscriptomics. Metagenomic analysis revealed that populations related to cultured AA degraders had an abundance <2.5% of the sequences. In contrast, metagenomic-assembled bins related to uncultured Bacteroidales collectively accounted for >35% of the sequences. Phylogenetic analyses suggested that these Bacteroidales populations represented a yet-to-be characterized family lineage, i.e., Bacteroidetes vadinHA17. The bins possessed the genetic capacity related to protein degradation, including surface adhesion (3–7 genes), secreted peptidase (52–77 genes), and polypeptide-specific transporters (2–5 genes). Furthermore, metatranscriptomics revealed that these Bacteroidales populations expressed the complete metabolic pathways for degrading 16 to 17 types of AAs in enrichments fed with respective substrates. These characteristics were distinct from cultured AA degraders including Acidaminobacter and Peptoclostridium, suggesting the uncultured Bacteroidales were the major protein-hydrolyzing and AA-degrading populations. These uncultured Bacteroidales were further found to be dominant and active in full-scale anaerobic digesters, indicating their important ecological roles in the native habitats. “Candidatus Aminobacteroidaceae” was proposed to represent the previously uncharted family Bacteroidetes vadinHA17.

Chemical Composition, Amino Acid Profile and Angiotensin Converting Enzyme (ACE) Inhibitory Activities of Skipjack (Katsuwonus pelamis) Roe Hydrolyzate

Roe has a high protein content and a number of amino acids. The process of removing fat and hydrolyzate with enzymes leads to the breaking of the bonds, so that complex proteins are converted into short chain proteins or peptides and free amino acids. The peptide can act as bioactive and has an effect as antihypertensive, antibacterial, antioxidant and so on. This research was aimed at utilizing processed roes to make hydrolyzate which had previously viewed the chemical composition both fresh and defatted, and to determine the protein profile of the roes from hydrolyzate. The research data were analyzed descriptively, and the average value and standard deviation were calculated. The results showed that skipjack roes have a fairly complete chemical composition, such as Proximate (protein, fat, moisture, ash, and carbohydrates), with values, respectively 19,19%, 0,67%, 76,32%, 2,51% and 1,31%. It was also found that the dominant amino acid composition of defatted skipjack mature roes is lysine, glutamate and leusine with values, respectively 12.65, 11.20 and 7.72 g/100 g protein and have activity as an angiotensin converting enzyme inhibitory. The ACE inhibitory activity of Skipjack roe hydrolysates of crude papain enzyme from immature and mature value, respectively 36.62% and 38.82%, while pure papain enzyme from immature and mature value respectively 42.63% and 47.54%. The protein profile of the immature roe hydrolyzate range from 10.88 to 125,80 kDA, while the mature roe hydrolysates range from 10.08 to 125,30 kDa.

Seasonality is more important than forest type in regulating the pool size and composition of soil soluble N in temperate forests

Soil soluble nitrogen (N) is crucial to the N nutrition and productivity of plants. Consequently, understanding the factors that affect its pool size and composition is of considerable importance. Here, six typical forest types in northeast China were investigated to determine the dynamics of soil soluble N across seasons and plant communities, and the potential drivers. Soil free amino acids, NH4+, NO3−, dissolved organic N (DON) and a variety of soil characteristics were measured over the growing season (from May to September). Seasonality showed a stronger effect on the availability of soil inorganic N and free amino acids than vegetation. The coefficients of variation of soil inorganic N, amino acid-N and the potential drivers (moisture and DON) appeared to be greater for season, and the concentrations of these available N sources tended to be higher at the beginning than at the height of growing season. Potential soil drivers (e.g. moisture, microbial biomass-N and DON) and plant phenology together drove the seasonal dynamics of inorganic N and amino acid-N. Arginine, histidine, serine, leucine, aspartic acid, glycine, glutamic acid and proline composed the dominant soil amino acid pool in the temperate forest soils. The basic amino acids (arginine and histidine) were consistently dominant irrespective of vegetation and season, suggesting that selective sorption by the soil solid phase could play an important role in regulating the cycling of amino acid-N in these temperate forest ecosystems. This research indicates that changes in local soil properties, and plant phenology caused by seasonality, exert a powerful influence on the characteristics of plant-soil N cycling.