Dominant Amino Acids Research Articles

Molecular epidemiology and recombination of enterovirus D68 in China

Enterovirus D68 (EV-D68), a member of Enterovirus genus of the Picornaviridae family, mainly causes respiratory system-related diseases as well as neurological complications in some patients. At present, there is no effective vaccine or treatment for the virus. The aim of this research was to systematically analyse the molecular epidemiology, recombination and changes in the epitope of EV-D68 in China from 2008 to 2022. Through phylogenetic analysis based on VP1 sequences, it was found that there was limited information about EV-D68 infection before 2011 and that EV-D68 infection was dominated by the A2 gene subtype from 2011 to 2013 and the B3 genotype from 2014 to 2018, during which A2 and B3 were coprevalent and alternately prevalent. We also constructed a phylogenetic tree using the EV-D68 full-length genome sequences, and the genotype of each sequence was consistent with that of the VP1 sequence evolutionary tree. Recombination analysis showed that MH341715 underwent intertypic recombination with the A2 genotype MH341729 at the 5′ untranslated region (5’UTR) and that P1-P3 underwent recombination with the B3 genotype MH341712. The capsid protein VP1 is one of the most important structural proteins. In VP1, the BC-loop (89–105 amino acids) and DE-loop (140–152 amino acids) are the most variable domains on the surface of the virus and are associated with epitopes. In this study, it was found that the dominant amino acid composition of the BC-loop and DE-loop continued to change with the epidemic of the virus; the amino acid composition also differed in different regions of the same genotypes. The ongoing genomic and molecular epidemiology of EV-D68 remains important for predicting emergence of new viruses and preventing major outbreaks of respiratory diseases.

ИЗУЧЕНИЕ АМИНОКИСЛОТНОГО СОСТАВА ЛЕСПЕДЕЦЫ ДВУЦВЕТНОЙ, ПРОИЗРАСТАЮЩЕЙ В КРАСНОДАРСКОМ КРАЕ

As is known, biologically active compounds in plants are in complexes easily absorbed by the human body and in biologically available concentrations, therefore they have a higher phar-macological activity compared to synthetic analogues. Plants synthesize all the amino acids necessary to build protein molecules. The ability of plant amino acids to participate in the as-similation of other biologically active substances by the body, as well as a wide range of their biochemical, and as a result, pharmacological action, attracts more and more attention of re-searchers and the study of the composition and content of amino acids in medicinal plant raw materials as potential sources of drugs. That is why the study of the qualitative and quantita-tive content of amino acids in medicinal plant raw materials and in preparations derived from it is of great practical importance and of a certain scientific interest. The experience of using shoots of Lespedeza bicolor in official and folk medicine tes-tifies to its wide therapeutic possibilities, which served as the basis for research to clarify its chemical composition in relation to amino acids. This paper presents data on the qualitative and quantitative amino acid composition of the aerial organs of Lespedeza bicolor (Lespedeza bicolor L, plant family Fabaceae) growing in the Krasnodar Territory. A comparative study of the main essential and non-essential amino acids in flowers, leaves and shoots of Lespede-za bicolor was carried out by capillary electrophoresis. It has been established that the flowers and leaves of Lespedeza bicolor contain 11 amino acids each, the dominant amino acid of both flowers and leaves is proline; Lespedeza bicolor shoots contain 12 amino acids, 6 of which are essential (threonine, valine, methionine, leucine, phenylalanine, lysine). Leucine is present only in the leaves, and cysteine only in the flowers of the studied plant

SLC38A2 and glutamine signalling in cDC1s dictate anti-tumour immunity

Cancer cells evade T cell-mediated killing through tumour–immune interactions whose mechanisms are not well understood1,2. Dendritic cells (DCs), especially type-1 conventional DCs (cDC1s), mediate T cell priming and therapeutic efficacy against tumours3. DC functions are orchestrated by pattern recognition receptors3–5, although other signals involved remain incompletely defined. Nutrients are emerging mediators of adaptive immunity6–8, but whether nutrients affect DC function or communication between innate and adaptive immune cells is largely unresolved. Here we establish glutamine as an intercellular metabolic checkpoint that dictates tumour–cDC1 crosstalk and licenses cDC1 function in activating cytotoxic T cells. Intratumoral glutamine supplementation inhibits tumour growth by augmenting cDC1-mediated CD8+ T cell immunity, and overcomes therapeutic resistance to checkpoint blockade and T cell-mediated immunotherapies. Mechanistically, tumour cells and cDC1s compete for glutamine uptake via the transporter SLC38A2 to tune anti-tumour immunity. Nutrient screening and integrative analyses show that glutamine is the dominant amino acid in promoting cDC1 function. Further, glutamine signalling via FLCN impinges on TFEB function. Loss of FLCN in DCs selectively impairs cDC1 function in vivo in a TFEB-dependent manner and phenocopies SLC38A2 deficiency by eliminating the anti-tumour therapeutic effect of glutamine supplementation. Our findings establish glutamine-mediated intercellular metabolic crosstalk between tumour cells and cDC1s that underpins tumour immune evasion, and reveal glutamine acquisition and signalling in cDC1s as limiting events for DC activation and putative targets for cancer treatment.

Amino acids, fatty acids and mineral elements composition of Roystonea regia and Ptychosperma macarthurii palm kernels

Roystonea regia and Ptychosperma macarthurii are exotic palm species widely grown in Nigeria as ornamentals. The kernels of R. regia and P. macarthurii were subjected to amino acids, fatty acids, and mineral elements analyses in this study. Glutamic acid (13. 64 and 14.00 g/100 g), aspartic acid (9.72 and 9.50 g/100 g), arginine (8.68 and 7.49 g/100 g), and leucine (7.23 and 7.98 g/100 g) were the dominant amino acids in R. regia and P. macarthurii seeds. The percentage yields of kernel oils were 13.9 and 1.7% for R. regia and P. macarthurii, respectively. Gas chromatograph facilitated the identification of thirteen fatty acids, mainly comprised of oleic acid (25.19 and 35.64%), linoleic acid (57.88 and 45.60%), and palmitic acid (9.6 and 10.03%) in R. regia and P. macarthurii, respectively. The analysis also revealed the high unsaturated nature of fixed oils of R. regia (83.63%) and P. macarthurii kernels (81.66%). Calcuim, copper, iron, zinc, magnesium, manganese, sodium, and potassium were also detected in the kernels; majorly, calcium (71.5 mg/L) and magnesium (23.1 mg/L) in P. macarthurii kernels, whereas sodium (24.6 ppm) and potassium levels (50.1 ppm) were higher in R. regia kernels. These results reveal the high amino acids, fatty acids, and mineral elements content of R. regia and P. macarthurii kernels. These unexploited palm fruits could be properly utilized as animal feed, edible oil, or for other industrial purposes with the knowledge of its nutritional value and fixed oil content.

Keratinase Production by Bacillus sp. MD24 in Sub-merge and Solid State Fermentation

Chicken feathers are valuable solid waste that mainly contains insoluble proteins called keratin. Naturally, keratin is degraded by microbes that produce a specific protease called keratinase. Many reports have been addressed to study Bacillus species as keratin-degrading microbes. However, most reported works were using pathogenic soil Bacillus. Our work has been concentrated on keratinase produced by a soil bacterium, Bacillus sp. MD24 and we confirmed it as a non-pathogenic bacterium. This report describes the different profiles of keratinase fermentation between sub-merged fermentation (SmF) and solid-state fermentation (SSF) using chicken feathers as a sole carbon and nitrogen source. Keratinase production and weight loss were followed for 10 consecutive days, the keratinase molecular weight was investigated, the type and concentration of 18 amino acids were determined using LC-MS/MS after 10 days to seek its potential as the amino acid source, and protein by-product concentration was measured. The results showed that keratinase production as well as weight loss in SmF was better compared to SSF with different optimum production times. Surprisingly, L-arginine was a dominant amino acid in SmF hydrolysate which contained 42.06% of total amino acids and made Bacillus sp. MD24 is a potential organism for L-arginine production. As protein by-product concentration was relatively low in both conditions showing effective utilization of chicken feathers as matter and energy source, consequently, cell-free keratinase should be applied to degrade chicken feathers into valuable materials.

Composition Analysis and Nutritional Value Evaluation of Amino Acids in the Fruit of 161 Jujube Cultivars.

Amino acids are an essential group of compounds involved in protein synthesis and various metabolic and immune reactions in the human body. Chinese jujubes (Ziziphus jujuba Mill.) are an important fruit and medicinal plant which are native to China and have been introduced into around 50 countries. However, systematic research on the composition and content diversity of amino acids in the jujube is still lacking. In this experiment, the amino acid composition and the contents of the dominant amino acids in the fruit of 161 cultivars of jujube were determined by HPLC. Of the twenty-one kinds of amino acids detected, a total of fourteen kinds of amino acids were detected, of which eight kinds of amino acids were relatively high, including five essential amino acids (threonine, valine, isoleucine, leucine, and phenylalanine) and three nonessential amino acids (glycine, alanine, and proline). However, the contents of the remaining six amino acids were relatively low (aspartic acid, glutamic acid, histidine, serine, arginine, and tryptophan). Therefore, the eight primary amino acids were used as the index to evaluate the amino acids of 161 jujube varieties. Proline accounts for 56.8% of the total amino acid content among the eight amino acids. The total content of the eight primary amino acids in most jujube varieties was 1-1.5 g/100 g, and the highest content of 'Zaoqiangmalianzao' was 2.356 g/100 g. The average content of proline was 6.01-14.84 times that of the other seven amino acids. According to the WHO/FAO revised model spectrum of ideal essential amino acids for humans, 19 cultivars met the E/T (essential amino acids/total amino acids) standard, and their values ranged from 35% to 45%; 12 cultivars meet E/NE (non-essential amino acids) ≥ 60%. All cultivars reached the requirement of BC (branched-chain amino acids)/E ≥ 40% with 15 cultivars over 68%. One hundred and fifty-seven cultivars reach the standard of BC/A (aromatic amino acids) ≈ 3.0~3.5. The amino acid ratio coefficient analysis showed that phenylalanine was the first limiting amino acid of all the jujube cultivars. The SRC (the score of amino acid ratio coefficient) values of 134 cultivars were between 50% and 70%, with 12 cultivars over 70%, indicating that jujube fruits are of high nutritional value in terms of amino acids. Based on the principal component analysis and comprehensive ranking of amino acid nutritional value, the top five cultivars were screened from the 161 ones tested, i.e., 'Tengzhouchanghongzao', 'Xinzhengxiaoyuanzao', 'Hanguowudeng', 'Xuputiansuanzao', and 'Lichengxiaozao'. This study established, firstly, a complete basic data analysis of amino acid content in jujube fruit which could be used to select germplasm resources suitable for developing functional amino acid food, and provide theoretical support for the high value utilization of amino acids in jujubes.

In vitro antioxidant and anti-inflammatory properties of Artocarpus altilis (Parkinson) Fosberg (seedless breadfruit) fruit pulp protein hydrolysates

Protein hydrolysates from dietary sources possess many physiological and biological properties. Artocarpus altilis is an evergreen multipurpose plant with many benefits. Therefore, this study evaluates in vitro antioxidant and anti-inflammatory properties of A. altilis protein hydrolysates. Protein was isolated from A. altilis and hydrolysed with pepsin and trypsin separately using different enzyme: substrate ratios (1:8, 1:16, 1:32). Antioxidant properties investigated included Fe2+-chelating, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and hydrogen peroxide radical scavenging activities. Anti-inflammatory activities were determined using effects on hypotonic solution-induced cell lysis on red blood cell membrane stabilisation and heat-induced protein denaturation. The degree of hydrolysis of trypsin hydrolysate increased with increasing enzyme–substrate ratio, while pepsin hydrolysate decreased as the enzyme–substrate ratio increased. The dominant amino acids in A. altilis protein and hydrolysates were glutamate, aspartate and leucine. Protein hydrolysates obtained from pepsin and trypsin digestion had DPPH scavenging abilities of 43.0 ± 0.01% and 22.2 ± 0.01%, respectively. However, trypsin-hydrolysed protein had a high Fe2+-chelating ability, while pepsin-hydrolysed protein had high hydrogen peroxide scavenging ability. Trypsin-hydrolysed protein showed good membrane stability and inhibition of protein denaturation. The results indicated that A. altilis protein hydrolysates possess significant antioxidant and anti-inflammatory effects and can further lend support to food industries as functional foods.

Characterization and Development of Gelatin from Cow Bones: Investigation of the Effect of Solvents Used for Soaking Beef Bones

Beef bones contain a gelatin component that can be further extracted. This extraction process requires the right solvent to produce good yield and quality. Gelatin has multifunctional properties, namely biodegradable, biocompatible and non-toxic. This is because it is a natural ingredient that contains high amino acids. The most dominant amino acid content as a parameter for determining the quality of gelatin is proline, glycine, and hydroxyproline. The purpose of this study was to study the effect of the solvent used as a medium for soaking cow bones to be converted into gelatin. The solvent variations used include NaOH, HCl, H2SO4, CH3COOH, and NaHCO2. The concentration variations are 4, 5, 6, 7, 8 (%). This research method includes the preparation of cow bone samples, fat removal, mineral removal, soaking for 7 days, and extraction. The extraction process was carried out with variations times of 4 h and 6 h. The results of the study showed that the highest yield value was with 5% HCl solvent with 4 h extraction time of 26.5% with 8.67% water content, 0.9% ash content, pH 4.64, and viscosity 3.19 cP (p < 0.05). A good isoelectric point is produced when using an acidic solvent, which is between 5.3–5.8. The cross-linking of gelatin with chitosan, glutaraldehyde, and glucose was successfully carried out with the FTIR absorption indicator at a wavelength of 3200 cm−1, which indicates the presence of hydrogen bonds, 1022 cm−1, which indicates the breakdown of aldehyde bonds in glutaraldehyde compounds into C-O bonds. According to the microbial test, when gelatin is combined with chitosan, there will be an increase in the microbial inhibition zone. This shows that the development of gelatin materials is very prospective and promising.

Exploring the Amino-Acid Composition, Secondary Structure, and Physicochemical and Functional Properties of Chickpea Protein Isolates.

This study examined the amino-acid profile, secondary structure, and physicochemical and functional properties of proteins isolated from Anatolian chickpea landraces. Secondary objective of the study was to determine whether a relationship exists between the amino-acid composition and physicochemical and functional properties. Aspartic acid and glutamic acid were the dominant amino acids, while the isolates were deficient in methionine. Secondary structures were determined by Fourier transform infrared spectroscopy, where the β-sheet was shown to be dominant. The denaturation temperature of the isolates was between 87 and 145 °C, and the highest net surface charge (≃28.6 mV) and solubility (∼95.0%) were observed at pH 9.0-10.0. The isolates' water-holding capacity varied between 2.1 and 2.7 g water/g protein, whereas their oil-holding capacity ranged between 3.4 and 4.4 g oil/g protein. Emulsion capacity, emulsifying activity, and the stability indices of isolates were found to be between 401.2 and 469.1 g oil/g protein, 14.5 and 25.7 m2/g, and 45.7 and 146.9 min, respectively. Isolates of Hisar and Erzincan chickpeas exhibited good emulsifying properties. The Yasa isolate had a relatively high hydrophobic amino-acid content and delivered the best gelation performance. Overall, significant differences in the characteristics of proteins were observed among the different chickpea landraces studied.

Nutritional composition of tauco as Indonesian fermented soybean paste

Tauco is a fermented soybean paste like miso but typical from Indonesia, commonly used as umami seasoning. This study objective was to evaluate the nutritional composition of diverse tauco products found in Indonesia and to determine a potential tauco product characterized by certain amino acids related to umami peptides (Asp, Glu, Gly, Ser, Thr, Val). Proximate composition, NaCl salt, total sugars, total acids, and total amino acid profiles of 24 tauco products, collected from 24 producers in 7 provinces in Indonesia, were analyzed. The proximate composition mapped tauco into solid (containing 29.2–35.3% moisture on wet weight basis or ww), semisolid (42.2–54.5% ww moisture), and liquid (56.2–68.1% ww moisture). Solid tauco composed of 54.7–65.2% carbohydrates, 10.0–22.8% ashes, 7.13–16.9% NaCl salt, 9.72–11.9% crude proteins, 11.9–27.0% total sugars, 6.98–23.4% crude fats, 1.24–2.18% total acids, and 11.4–17.5% total amino acids on dry weight basis (dw). In contrast, liquid tauco consisted of 8.47–56.5% dw carbohydrates, 17.1–73.8% dw ashes, 10.7–68.4% dw NaCl, 20.4–30.9% dw crude proteins, 4.45–29.9.5% dw total sugars, 1.30–18.9% dw crude fats, 1.65–5.36% dw total acids, and 14.1–24.6% dw total amino acids. All tauco had a slight acidic pH, ranged from 4.38 to 5.91. Glu and Asp were the dominant amino acids of tauco, comprising 25–40% of total amino acids. Mapping of total amino acid profile mentioned a tauco product, characterized by the highest concentration of amino acids related to umami peptides. This finding leads to the exploration of umami peptides to reveal the science behind its traditional use as umami seasoning.

Amino Acid and Mineral Profiles of Fresh Snakehead (Channa striata) Meat to Potential as an Immune System

During the COVID-19 pandemic, Riau Province experienced an increase in fish consumption as an effort to improve the immune system in preventing the transmission of COVID-19. The increase in fish consumption is in line with the increase in the production of snakehead fish commodity fisheries in Riau Province. However, research on the nutritional content of snakehead fish from Riau waters has not been reported. So, this study aimed to characterize the snakehead fish meat’s amino acid and mineral profiles. Snakehead fish was obtained from Bengkuang Lake, Riau Province then analyzed physically (fish freshness detection, morphometrics, and fish body proportions) and chemically (proximate, amino acids, and minerals). The results showed that the snakehead fish meat obtained from Riau waters was in fresh condition with a body length of 30.33 cm and a body weight of 252 g, which was dominated by the proportion of the body part of the meat of 37.38%. Based on chemical characteristics, snakehead fish meat contained 16.99% protein and 1.96% ash. Snakehead fish meat also had dominant amino acids, namely leucine 0.539% and glutamic acid 1.446%. Furthermore, snakehead fish meat minerals were dominated by Fe 6.217% and Zn 2.235%. The presence of amino acids leucine, glutamic acid, and Fe and Zn minerals play an important role in the wound healing process and immune system.

Bioactive Components of Meat Powder and Viscera-Gonad Holothuria Scabra from Terung Island Waters, Batam, Indonesia

Holothuria scabra contains some bioactive components that are highly needed by humans in functional and healthy food. This study aims to determine differences in chemical content and bioactive components, the amount of water-soluble protein, salt-soluble protein, amino acid profile, and fatty acid profile from meat powder ingredients and viscera-gonad. The research stages include the weeding process and sample preparation, making meat powder and sea cucumber viscera-gonad, and testing the chemical and bioactive composition. Yields of sea cucumber meat powder and viscera-gonads were 95.45% and 95.92%, respectively. Sea cucumber meat powder has a slightly grayish creamy white color (69.32% white degree), while the sea cucumber gonad powder has a slightly brownish grayish-white color (63.09% white degree). The chemical contents of meat powder and edible gonad of sea cucumber are water content 9.12% and 16.12%, protein 79.50% (dw) and 51.83% (dw), fat 2.14% (dw) and 20.09% (dw), ash 4.14% (dw) and 9.52% (dw), carbohydrates 13.88% (dw) and 18.57% (dw), respectively. Components of bioactive in sea cucumber extract generally contain flavonoid components, saponins, alkaloids and steroids, and specifically, the meat is not identified flavonoid compounds. Water-soluble protein and salt-soluble protein in the sea cucumber powder decreased compared to the fresh sea cucumber. Essential amino acids in sea cucumber amino were most abundant in meat of 74.09% and viscera-gonads of 49.95%. The dominant essential amino acids in sea cucumber meat included lysine (6.78%) and leucine (7.11%), in the viscera-gonad of leucine amino acid types (3.81%) and arginine (4.16%). The amount of total fatty acids in sea cucumber meat (1.71%) was smaller than that of sea cucumber gonads (18.49%). The types of fatty acids identified in the meat and the sea cucumber viscera-gonad were saturated fatty acids of 1.08% and 8.97%; saturated fatty acids of 0.63% and 4.96%; while compounds saturated fatty acids in meat were not identified and in viscera-gonads by 4.56%.

Phytochemical analysis of leaves and stems of Physalis alkekengi L. (Solanaceae)

Abstract Physalis alkekengi L. (Solanaceae) is encountered in different regions of Bulgaria as a wild growing or ornamental plant. The objective of this work was to characterize the phytochemical composition (macro and micro components) of the leaves and stems of two local phenotypes (PA-SB and PA-NB), with the view of revealing their use potential. The dry leaves contained (DW) protein (16.25 and 19.27%), cellulose (25.16 and 25.31%), and ash (18.28 and 16.16%) and the stems contained protein (6.83 and 7.35%), cellulose (39.34 and 38.25%), and ash (15.01 and 7.48%) for PA-SB and PA-NB, respectively. The dominant amino acids (by HPLC) in the leaves of both phenotypes were arginine (21.3–22.3 mg/g) and aspartic acid (8.8–18.4 mg/g), and those in the stems were proline and aspartic acid for PA-SB (8.8, 7.7 mg/g); isoleucine and tyrosine for PA-NB (12.8, 6.6 mg/g). Mineral elements, determined by AAS (K, Ca, Mg, Na, Cu, Fe, Zn, Mn, Pb, Cr), also varied between phenotypes and plant parts. The leaves alone were further processed by extraction with n-hexane, for the identification of leaf volatiles (by gas chromatography-mass spectrometry). The analysis identified 28 components (97.99%) in the leaf extract of PA-SB and 32 components (97.50%) in that of PA-NB. The volatile profile of PA-SB leaves was dominated by diterpenes (49.96%) and oxygenated sesquiterpenes (35.61%), while that of PA-NB was dominated by oxygenated aliphatics (40.01%) and diterpenes (35.19%). To the best of our knowledge, the study provides the first data about the phytochemical composition of the leaves and stems of P. alkekengi from Bulgaria, in a direct comparison of phenotypes from two distinct wild populations, which could be of further scientific interest.

Studying the characteristics of nanobody CDR regions based on sequence analysis in combination with 3D structures

BackgroundSingle-domain antibodies or nanobodies have recently attracted much attention in research and applications because of their great potential and advantage over conventional antibodies. However, isolation of candidate nanobodies in the lab has been costly and time-consuming. Screening of leading nanobody candidates through synthetic libraries is a promising alternative, but it requires prior knowledge to control the diversity of the complementarity-determining regions (CDRs) while still maintaining functionality. In this work, we identified sequence characteristics that could contribute to nanobody functionality by analyzing three datasets, CDR1, CDR2, and CDR3. ResultsBy classification of amino acids based on physicochemical properties, we found that two different amino acid groups were sufficient for CDRs. The nonpolar group accounted for half of the total amino acid composition in these sequences. Observation of the highest occurrence of each amino acid revealed that the usage of some important amino acids such as tyrosine and serine was highly correlated with the length of the CDR3. Amino acid repeat motifs were also under-represented and highly restricted as 3-mers. Inspecting the crystallographic data also demonstrated conservation in structural coordinates of dominant amino acids such as methionine, isoleucine, valine, threonine, and tyrosine and certain positions in the CDR1, CDR2, and CDR3 sequences. ConclusionsWe identified sequence characteristics that contributed to functional nanobodies including amino acid groups, the occurrence of each kind of amino acids, and repeat patterns. These results provide a simple set of rules to make it easier to generate desired candidates by computational means; also, they can be used as a reference to evaluate synthetic nanobodies.

Salmon Skin Acid-Soluble Collagen Produced by A Simplified Recovery Process: Yield, Compositions, and Molecular Characteristics

Acid-soluble collagen (ASC) is generally extracted by acid solubilization, followed by precipitation and dialysis. Such a process is typically time consuming and tedious, especially for dialysis. A simplified recovery process based on water washing/centrifugation of collagen pellets to replace dialysis was successfully developed. An ASC pellet from salmon (Oncorhynchus nerka) skin was obtained by salt precipitation (2.6 M). The pellet was washed with 50 volumes of distilled water (DW) and centrifuged for 0–3 cycles before lyophilization. As the washing cycles augmented, decreases (p < 0.05) in the NaCl content with a coincidental increase (p < 0.05) in the hydroxyproline content were attained. Similar protein patterns between all of the ASC samples, regardless of washing cycles, were noticeable. All of the ASCs were classified as type I collagen. FTIR spectra revealed that ASC possessed a triple helical structure with sufficient washing cycles. ASC washed with DW for three cycles (ASC-3C) was selected and characterized. ASC-3C showed high extraction yield (36.73%) and had high lightness. It exhibited high thermal stability (Tmax = 37 °C) and had an ordered phase structure. Glycine and imino acids were the dominant amino acids in ASC-3C. Therefore, a simplified recovery process could be adopted for ASC production, in which the shorter time was used without adverse effects toward ASC.

Изменение аминокислотного состава природных углеродистых веществ и некоторых синтетических аналогов в ряду карбонизации

Amino acids are important records of geochemical processes in sedimentary rocks. The knowledge about changing the composition of amino acids is important for our understanding of genetics of organic compounds in the geological records. In the presented work, compositions of amino acids in natural solid bitumens, graphites and some synthesized carbonaceous materials were investigated. We determined that the content of amino acids decreases with increasing temperature of the formation of natural carbonaceous substances. the content of aliphatic amino acids gradually increases with increasing degree of transformation in the carbonization (dehydrogenation) series, mainly due to glycine, alanine and leucine. The revealed changes in the amino acid composition of natural carbonaceous substances are associated with the genesis of the initial organic matter, as with as the content of carbonaceous matter and its interaction with the mineral component.
 We showed that the selection of dominant individual amino acids without involvement of statistical methods did not allow distinguishing some types of natural carbonaceous materials. At the same time, lots of amino acids were identified by statistical methods, statistically significantly distinguishing all the studied types of solid natural bitumen and graphite.

Physiological response of the razor clam Sinonovacula constricta exposed to hyposalinity stress

The razor clam Sinonovacula constricta is an economically important bivalve species in China, which inhabits the mudflat of intertidal and estuaries areas and frequently suffers the low salinity stress due to heavy rain events. The present study investigated the effects of hyposalinity stress (salinity 10, 5, 3, and 1) on osmoregulation and haemolymph microbiota in S. constricta after 7 days of exposure. The results showed that the survival rate of razor clams was only significantly reduced in the 1 ppt group compared to the control group (salinity 20) (P < 0.05). Haemolymph osmolality in razor clams reduced significantly with decreasing salinities (P < 0.05). Taurine, arginine, alanine and ornithine were the dominant free amino acids (FAAs) with higher contents in the haemolymph. Exposure to low salinities altered the composition of haemolymph FAAs, with alanine being the highest in the control group and taurine being the highest in the low salinity (LS) groups. Hyposalinity stress caused an increase in Na+/K+-ATPase (NKA) activity in gills, and histological analysis revealed severe hyperplasia in gills and a significant reduction in the length of gill filaments (P < 0.05). The microbial community variation in the haemolymph assessed by 16S rRNA sequencing explains that bacterial communities was shifted under low salinity stress. At the genus level, the relative abundance of Marinobacterium, Marinomonas and Pseudomonas changed significantly under hyposalinity stress (P < 0.05). These findings give further insight into the physiological responses and potential adaptation strategies of razor clams to hyposalinity stress and provide information for the development of inland low salinity culture.

Antimicrobial resistance of Salmonella Indiana from retail chickens in China and emergence of an mcr-1-harboring isolate with concurrent resistance to ciprofloxacin, cefotaxime, and colistin.

Salmonella enterica serotype Indiana (S. Indiana) in Chinese poultry meat has aroused widespread concern because of its high prevalence and strong antimicrobial resistance. In consideration of the relationship in our previous study between S. Indiana and co-resistance to ciprofloxacin and cefotaxime (CIP-CTX), which were the first-line drug which were used in Salmonella infection in clinical, the antimicrobial resistance (AMR) of 224 CIP-CTX co-resistant S. Indiana isolated from retail chicken samples in China were investigated, with the aim of characterizing the AMR profiles and related resistance mechanisms to ciprofloxacin and cefotaxime among these CIP-CTX co-resistant S. Indiana isolates, all of which showed multi-drug-resistant (MDR) phenotypes. GyrA (S83F and D87N/G) with ParC (T57S and S80R) were the dominant amino acid substitution types, with oqxA, oqxB, and aac (6′)-Ib-cr identified as common plasmid-mediated quinolone resistance (PMQR)-encoding genes. Five blaCTX-M gene subtypes were identified with blaCTX-M-65 ranking at the top. Equally important, we obtained one isolate CFSA664 harboring the mcr-1 gene was ESBL producer with co-resistance to nine in ten classes of tested drugs inclduing colistin. A single circular chromosome and 3 circular plasmids were found in its genome. Among the 26 AMR genes identified, 24 were located on plasmid pCFSA664-1, including three ESBL genes, while plasmid pCFSA664-3 owning only the mcr-1 gene and sharing the same backbone structure with plasmids from Enterobacteriaceae. No insertion sequences were found near the mcr-1 gene but a relaxase-encoding gene in the flank, which could transfer into E. coli J53 at a relatively high frequency. S. Indiana in this study exhibited highly drug-resistant phenotypes, contributing to the acceleration of the dissemination and emergence of this pathogen among different sources. Surveillance and a One Health strategy are needed to limit the emergence of S. Indiana along the food chain.

The impact of roasting and steaming on savory flavors contributed by amino acids, 5′-nucleotides, and volatiles in Agaricus bisporus mushrooms

Mushrooms have been used to enhance meat flavor, although studies regarding cooking approach and mushroom type impact on savory flavors are limited. This study aimed to compare taste-related compounds (free amino acids and 5′-nucleotides) and volatile aromas in raw, steamed, and roasted white and crimini Agaricus bisporus mushrooms. Using gas chromatography–mass spectrometry (GC–MS) and high-performance liquid chromatography–ultraviolet detection (HPLC–UV), 22 free amino acids were quantified. Glu (umami taste) was the most dominant amino acid in both raw and cooked white and crimini, while Asp (umami taste) content was much lower. These mushrooms also contained all essential amino acids and other sweet- and bitter-related amino acids. Five 5′-nucleotides were quantified using HPLC–UV, with 5′-GMP (umami taste) being the most dominant, followed by 5′-CMP and 5′-UMP (tasteless). Cooking significantly decreased free amino acids by 7-14 times and 5′-nucleotides by 3-8 times. GC–MS identified 125 volatiles in total, with only around 45 of those presenting in raw mushrooms. Cooking increased almost all volatiles by number and quantity (20–68 times). Variety difference was minimal for free amino acids and 5′-nucleotides, whereas it was more obvious for volatiles. These results demonstrated how cooking impacted mushroom free amino acids, 5′-nucleotides, and volatiles, providing evidence for mushroom savory flavor changes due to cooking.

Nectar Abundance and Nectar Composition in Selected Rubus idaeus L. Varieties

The increasing commercial production of R. idaeus offers insects nectar and pollen rewards, thus increasing the chance of cross-pollination, which enhances fruit yields. The knowledge of nectar characteristics may help farmers/beekeepers to improve the quality of their products. Therefore, we determined and compared nectar weight, sugar concentration and weight, and the qualitative and quantitative composition of sugars and amino acids in the nectar of six raspberry cultivars: three biennial and three repeated fruiting cultivars. The nectary abundance in these cultivars ranged between 20.2 ± 3.84 mg (‘Polka’) and 26.4 ± 7.3 mg (‘Glen Ample’) of nectar per flower with a sugar concentration of 34.6 ± 5.61–47.3 ± 9.33%. The contents of glucose and fructose (g/100 g) were in the range from 42.96 ± 0.71 (‘Glen Ample’) to 46.94 ± 0.55 (‘Laszka’) and from 50.7 ± 1.43 (‘Polka’) to 54.2 ± 0.72 (‘Radziejowa’). Sucrose was detected only in ‘Glen Ample’ (5.6 ± 1.12 g/100 g) and ‘Polka’ (6.2 ± 0.95 g/100 g). Taking into account the increasing sugar weight in the nectar, the cultivars were ranked as follows: ‘Polka’ &lt; ‘Polana’ &lt; ‘Radziejowa’ &lt; ‘Pokusa’ &lt; ‘Laszka’ &lt; ‘Glen Ample’. The nectar of the analyzed raspberry cultivars was classified as a hexose-dominant type. Aspartic acid, glutamic acid, and proline were the most dominant endogenous amino acids, whereas exogenous acids were dominated by lysine and leucine. The present results provide valuable information about the nutritious value of R. idaeus nectar for pollinators.