High Protein Content Research Articles

Effect of Differences in Protein Levels and Length of Fermentation Time on Physicochemical Characteristics of Caspian Sea Yoghurt Green Tea

Caspian sea inoculum has been widely used for yogurt production, but it is rarely used in making green tea powder (GTP) yoghurt using milk with different protein content. This study aims to determine the changes in the characteristics of GTP yoghurt with Caspian sea inoculum using low fat UHT milk (SLF) or full cream UHT milk (SFC) during the fermentation period at 0 and 16 hours. The results showed that use of different types of UHT milk affected physicochemical characteristics. Fermentation for 16 hours caused a decrease in the pH of the sample to pH 4.3-4.4, but it was negatively correlated with an increase in the acidity. In addition, fermentation resulted increase the value of L* (brightness). The SLF sample has a greener color than the SFC sample. The viscosity of GTP yoghurt increased significantly at 16 hours in SFC and SLF samples. After 16 hours fermentation, the TPC became 4.15 mg GAE/g and 4.45 mg GAE/g with IC50 values ​​of 37.51 g/mL and 23.95 g/mL in SLF and SFC samples. The high protein content in UHT milk affected the high acidity, viscosity, and syneresis values ​​resulting a decrease in the TPC of GTP yoghurt.

Application of a microalga, Tetradesmus obliquus PF3, for NO and CO2 removal from actual flue gas via cultivating in wastewater.

Greenhouse gas (GHG) emissions, particularly anthropogenic emissions, are the primary drivers of climate change. The cultivation of microalgae represents a highly promising strategy for mitigating atmospheric GHG levels. The growth characteristics and GHG mitigation capabilities of Tetradesmus obliquus PF3 were investigated in domestic wastewater at a thermal power plant. The maximum cell density and productivity were 1.52 ± 0.01 g L-1 and 0.33 ± 0.01 g L-1 day-1, respectively. Utilizing a serial configuration of two reactors, the elimination efficiency of NO and CO2 attained values of 78 ± 4% and 14 ± 4%, respectively. NO concentration at the outlet was less than 24.6 ± 2.9 mg m-3, meeting the latest Chinese discharge limits. Besides, the recovery efficiency of NO and CO2 increased to 77 ± 8% and 2.24 ± 0.04%, respectively, compared to that of the single reactor (40 ± 3%, 0.9 ± 0.0%). A removal efficiency of over 90% was achieved for TN and TP in domestic wastewater. The concentrations of COD (76.5 mg L-1), NH4+-N (0.9 mg L-1), TN(6.31 mg L-1), and TP (0.35 mg L-1) in effluent were below the thresholds of 100 mg L-1, 25 mg L-1, none data, and 3 mg L-1, respectively, complying with the Chinese Discharge Standard (Class II criteria set forth) for Municipal Wastewater Treatment Plants Pollutants. The harvested biomass exhibited a high content of carbohydrates and proteins, making it a viable feedstock for biofuels and bio-fertilizers. Our results demonstrate that Tetradesmus obliquus PF3-based flue gas treatment technology can simultaneously realize GHG removal, wastewater bio-remediation, and biomass recovery.

Morphology of the Digestive Tube of the Amazonian Freshwater Stingray Potamotrygon wallacei (Elasmobranchii: Potamotrygonidae): A Stereological Approach.

This work aimed to describe and quantify the tissue components of the digestive tube of the neotropical freshwater stingray, Potamotrygon wallacei. For this, conventional histology and stereological methods were used to estimate tissue volume. The volumes of the four fundamental layers and the tissue components in the stomach (cardiac and pyloric) and spiral intestine were also estimated. In the cardiac stomach, the mucosa layer occupies 44.7% of the total volume of the organ wall. The gastric glands are the main components, and these structures alone represent 49.7% of this layer. This large number of gastric glands suggests a high potential for processing food items with a high protein content. The stereological methods were sensitive enough to show a reduction in the volume of the gastric glands from the cardiac region toward the pyloric region. Gastric glands are absent in the pyloric region of the stomach. However, the muscularis becomes thicker towards the pyloric region. The increase in smooth muscle thickness is due to the thickening of the inner muscular layer. This suggests that the role of the pyloric stomach may be related to the mixing of the chyme and assisting its passage to the spiral intestine. In the spiral intestine, data on the volume of the mucosa layer (and epithelial lining) suggest that the spiral valve has a large absorptive area. In several respects, the morphology of the digestive tube of P. wallacei is similar to that of other batoids. However, its slight morphological variations may be related to the habitat specificity of this species.

Kadar Protein, Kadar Albumin, dan Tingkat Kesukaan Brownies Mocaf Ikan Gabus

Background: Brownies are generally made from wheat flour, but can be made with local food mocaf flour. Mocaf protein is lower than wheat flour, wheat flour has 8-13% protein while mocaf has 1.2% protein content. Objectives: The purpose of the study was to determine the addition of snakehead fish to protein levels, albumin levels, and preference test for mocaf brownies.The addition of snakehead fish to mocaf brownies aims to increase protein levels. Snakehead fish contains high protein and albumin,protein of 16.2g/100g and albumin content of 6.224g/100g. Preference test is researched to find out brownies are acceptable to consumers. Method: The study used the Complete Randomized Design experimental method with the additionof snakehead fish 0%;7.3%;9.6%;11.7%, repetition 6 times. Protein content testing is carried out by the kjeldahl method, albumin levels by the biuret method and preference levels by organoleptic tests. Data analysis of protein levels and albumin levels using the ANOVA one-way test, and analysis of favorability data using the Friedman Test test then proceed to the Wilcoxon test. Results: The test results of protein levels and albumin levels get a value of p >0.05, namely the addition of snakehead fish does not have a significant effect. The results of the favorability leveltest on color, aroma, taste get a value of p < 0.05 that the addition of snakehead fish has a significant effect and the texture of p > 0.05 is not significant. Test results with the addition of snakehead fish with the highest protein content and albumin content treatment 11.7%, the highest color test at 7.3% and 9.6%, the highest aroma test at 9.6%, the highest taste and texture test at 7.3%. Keywords : Albumin Levels, Mocaf Brownies, Preference Levels, Protein Levels, Snakehead Fish

Multiomics of a rice population identifies genes and genomic regions that bestow low glycemic index and high protein content

To counter the rising incidence of diabetes and to meet the daily protein needs, we created low glycemic index (GI) rice varieties with protein content (PC) surpassing 14%. In the development of recombinant inbred lines using Samba Mahsuri and IR36 amylose extender (IR36ae) as parental lines, we identified quantitative trait loci and genes associated with low GI, high amylose content (AC), and high PC. By integrating genetic techniques with classification models, this comprehensive approach identified candidate genes on chromosome 2 (qGI2.1/qAC2.1 spanning the region from 18.62 Mb to 19.95 Mb), exerting influence on low GI and high amylose. Notably, the phenotypic variant with high value was associated with the recessive allele of the starch branching enzyme 2b (sbeIIb). The genome-edited sbeIIb line confirmed low GI phenotype in milled rice grains. Further, combinations of alleles created by the highly significant SNPs from the targeted associations and epistatically interacting genes showed ultralow GI phenotypes with high amylose and high protein. Metabolomics analysis of rice with varying AC, PC, and GI revealed that the superior lines of high AC and PC, and low GI were preferentially enriched in glycolytic and amino acid metabolisms, whereas the inferior lines of low AC and PC and high GI were enriched with fatty acid metabolism. The high amylose high protein recombinant inbred line (HAHP_101) was enriched in essential amino acids like lysine. Such lines may be highly relevant for food product development to address diabetes and malnutrition.

Effect of ultrasound-assisted pH-shifting treatment on the physicochemical properties of melon seed protein

Melon seeds have received considerable attention in recent years because of their high protein content, but they have not yet been fully used. The modification of melon seed protein (MSP) using ultrasound-assisted pH-shifting treatment was investigated in this study by analyzing structural characteristics and functional properties. The particle size, free sulfhydryl content, surface hydrophobicity, solubility, secondary structure, water-holding capacity, oil-holding capacity, emulsification activity index, and emulsification stability index of MSP were determined. MSP treated with ultrasound-assisted, pH-shifting had a smaller particle size, lower free sulfhydryl content, higher surface hydrophobicity, and solubility increased from 43.67 % to 89.12 %. The secondary structure of MSP was affected by ultrasonic treatment, manifesting as an α-helix increase and β-helix, β-turn, and random coil content decrease, which may be the reason why the protein structure became more compact after treatment. The water and oil holding capacities of MSP increased from 2.74 g/g and 3.14 g/g in untreated samples to 3.19 g/g and 3.97 g/g for ultrasound-treated samples, and further increased to 3.97 g/g and 5.02 g/g for ultrasound-assisted, pH-shifting treatment at pH 9.0, respectively. The emulsification activity index of MSP was 21.11 m2/g before treatment and reached a maximum of 32.34 m2/g after ultrasound-assisted, pH-shifting treatment at pH 9.0. The emulsification stability of MSP was maximized by ultrasonic treatment at pH 7.0. Ultrasound-assisted, pH-shifting treatment can effectively improve the functional properties of MSP by modifying the protein structure, which improves the potential application of melon seed protein in the food industry.

Comprehensive analysis of Moringa oleifera leaves’ antioxidant properties in ovine cheese

This study aimed to enhance “Pecorino” type ovine cheese by adding Moringa oleifera leaves powder (MOLP). Cheese-making trials, conducted at industrial level, used raw ewes' milk and two selected Lactococcus lactis strains. The experimental plan included a control production (CTR), and two experimental productions with 1% or 2% MOLP addition (1-MOLP and 2-MOLP, respectively). MOLP did not hinder starters development, which reached about 8.0 Log CFU/g in 2-month ripened cheeses. Illumina results highlighted lactococci dominance in all trials [45.98%–62.48% of relative abundance (RA)]. Physicochemical analysis showed that MOLP-enriched cheeses had higher protein content and lower secondary lipid oxidation. The addition of MOLP increased total phenolic compounds in cheese, reaching 3.64 mg GAE/g in the 2-MOLP sample. MOLP-enriched cheeses showed significantly higher radical scavenging activity than CTR production (p < 0.0001). Ultrahigh-performance liquid chromatography-electrospray ionization tandem mass spectrometry (UHPLC-ESI-MS/MS) revealed increased levels of chlorogenic acid, protocatechuic acid, caffeic acid, and ferulic acid due to MOLP enrichment. In the presence of MOLP, cheese volatile organic compounds were affected by compounds like 2-octanone, 3-hexen-2-one, heptane, nonanol, and linalool. 1-MOLP cheese was comparable to CTR production in overall satisfaction (sensory evaluation). Including MOLP in cheese production offers exciting opportunities for functional Sicilian ewes’ milk products.

Macroparticle-enhanced morphology engineering of Cordyceps sinensis for high glucose fermentation to optimize the production of bioactive exopolysaccharides

Cordyceps sinensis is widely known for its therapeutic properties. Enhancing the yield of exopolysaccharides (EPS), which is crucial for its medicinal efficacy, is a major challenge. In this study, we applied high initial glucose concentrations with talc particles to enhance EPS production and assessed the cell morphology, intracellular biochemical reactants, and bioactivity contribution of glycoproteins. The use of 150 g/L glucose and 10 g/L 2000 mesh talc increased the EPS yield by 1.8-fold to 4.21 g/L. The addition of talc regulated cell morphology, facilitated the entry of oxygen molecules into the cells to produce a large amount of ATP for polysaccharide synthesis, and altered the cell wall structure to facilitate the secretion of EPS. Moreover, environmental stress resulted in a notable increase in intracellular reactive oxygen species levels, which can potentially enhance cell membrane permeability and promote EPS synthesis. Furthermore, the highest protein content in crude EPS corresponded to the maximum activation of alcohol dehydrogenase (ADH) of 44.2 %, suggesting a mechanistic relationship between the proteins and polysaccharides in the glycoproteins that influence the activation of ADH. These findings elucidate the intricate interplay between fermentation conditions and EPS production and provide new avenues for optimizing the fermentation process of CS-HKI to enhance its therapeutic applications.

Valorizing Arthrospira cell residues into polysaccharides: Characterization and application in yogurt

This study aimed to extract and characterize polysaccharides from Arthrospira cell residue and evaluate their application in yogurt. Four Arthrospira polysaccharides (APP-50, APP-60, APP-70, and APP-80) were obtained by different ethanol concentrations. With the increase in ethanol concentration, the component peaks of polysaccharide became less and the components were simpler. The results showed that APP-60 had the highest neutral sugar content and the densest spherical structure. APP-50 had the highest protein content, the strongest antioxidant capacity, the porous structure, and the structure was incomplete. The addition of polysaccharides increased the viscosity, storage modulus, loss modulus, and particle size of yogurt, and improved the stability of yogurt during long-term storage. The microstructure of yogurt with added polysaccharides was tighter and more orderly than that of the control yogurt. This study demonstrated that Arthrospira polysaccharides could be used as functional ingredients to enhance the quality and nutritional value of yogurt.

Utilization of roasted barley (Hordeum vulgare) and oat (Avena sativa) for the development of functional yogurt with special reference to storage stability

ABSTRACT The objective of the current study prepare yogurt enriched with roasted barley and oat flour in different treatments. The manual cleaning of oats and barley was carried out and placed in a traditional sand roaster with an iron pan at 280 ± 5°C for 20 seconds. Roasted barley and oat flours were used in different concentrations of 1:0; 3:0; 5:0; 0:1; 0:3; 0:5; 0.5:0.5; 1.5:1.5; and 2.5:2.5 g/100 g, respectively. The prepared yogurt was stored for 28 days at 4°C, and analyzed during the 7-day intervals. The results showed that roasted barley and oat flours contained higher concentrations of proteins (13.72 & 16.61%) and fibers (16.86 & 3.54%), which aided in the improvement of the properties of yogurt. The pH of the prepared yogurt was decreased (4.5 to 4.2), and titratable acidity was increased (0.61 to 0.70%) non-significantly in all treatments. The syneresis rate was decreased (25 to 19%) with increased concentrations of roasted barley and oats during storage. The microbial analysis of the fortified yogurt decreased the total plate count and total yeast count. Concludingly, roasted barley and oats improved the solid contents along with proteins, fats, and fiber contents of the prepared yogurts, improving the nutritional value of yogurt.

Growth and biomass of Wolffia arrhiza with different sources of organic fertilizer

Wolffia arrhiza has a growth rate and biomass as well as a good nutritional content for the growth of cultivated fish, especially herbivorous fish. Due to the high protein content (up to 45% of the dry weight), Wolffia is an excellent plant for the production of various biologically active substances, especially proteins. These plants can double every 1-6 days, similar to algae or mushrooms, and the number of leaves doubles every 2-3 days. This study aims to determine the effect of different fertilizer sources on doubling time, relative growth rate, population density and biomass of Wolffia arrhiza and water quality. The method used in this research is experimental. The research design used a completely randomized design (CRD) consisting of 4 treatments and 3 replications. The treatments were as follows: treatment A: chicken manure, B: cow manure, C: buffalo manure and D: goat manure with each dose of 200 grams. Parameters observed included doubling time, relative growth rate, population density, biomass and water quality parameters. The results showed that treatment B (cow manure) gave the highest value for doubling time, 1.59 days, relative growth rate 0.392 g/day, population density 209.75 ind/cm2, biomass 94.97. Keyword: Biomass; Fertilizer; Growth; Wolffia

Increasing fish production in recirculating aquaculture system by integrating a biofloc-worm reactor for protein recovery

Aquaculture, producing half of global fish production, offers a high-quality protein source for humans. Improving nitrogen use efficiency (NUE) through microbial protein recovery is crucial for increasing fish production and reducing environmental footprint. However, the poor palatability and high moisture content of microbial protein make its utilization challenging. Here, a biofloc-worm reactor was integrated into a recirculating aquaculture system (BW_RAS) for the first time to convert microbial protein into Tubificidae (Oligochaeta) biomass, which was used as direct feed for culturing fish. Batch experiments indicated that an aeration rate of 0.132 m3L−1h−1 and a worm density of 0.3 g cm−2 on the carrier were optimal for microbial biomass growth and worm predation, respectively. Compared to the biofloc reactor-based recirculating aquaculture system (B_RAS), the BW_RAS improved water quality, NUE, and fish production by 17.1 % during a 120-day aquaculture period. The abundance of heterotrophic aerobic denitrifier Deinococcus in BW_RAS was one order of magnitude higher than in B_RAS, while heterotrophic bacteria Mycobacterium was more abundant in B_RAS. Denitrifiers cooperated with organic matter degraders and nitrogen assimilation bacteria for protein recovery and gaseous nitrogen loss while competing with predatory bacteria. Function prediction and qPCR indicated greater aerobic respiration, nitrate assimilation, nitrification (AOB-amoA), and denitrification (napA, nirK, nirS, nosZI), but lower fermentation in BWR compared to BR. This study demonstrated that BW_RAS increased microbial protein production and aerobic nitrogen cycling through ongoing worm predation, further enhancing fish production to a commercially viable level.

Effects of higher dietary acid load: a narrative review with special emphasis in children.

Metabolic effects of high diet acid load (DAL) have been studied for years in adults, although only recently in children. Contemporary diets, especially those of Western societies, owe their acidogenic effect to high animal-origin protein content and low contribution of base-forming elements, such as fruits and vegetables. This imbalance, where dietary acid precursors exceed the body's buffering capacity, results in an acid-retaining state known by terms such as "eubicarbonatemic metabolic acidosis," "low-grade metabolic acidosis," "subclinical acidosis," or "acid stress". Its consequences have been linked to chronic systemic inflammation, contributing to various noncommunicable diseases traditionally considered more common in adulthood, but now have been recognized to originate at much earlier ages. In children, effects of high DAL are not limited to growth impairment caused by alterations of bone and muscle metabolism, but also represent a risk factor for conditions such as obesity, insulin resistance, diabetes, hypertension, urolithiasis, and chronic kidney disease (CKD). The possibility that high DAL may be a cause of chronic acid-retaining states in children with growth impairment should alert pediatricians and pediatric nephrologists, since its causes have been attributed traditionally to inborn errors of metabolism and renal pathologies such as CKD and renal tubular acidosis. The interplay between DAL, overall diet quality, and its cascading effects on children's health necessitates comprehensive nutritional assessments and interventions. This narrative review explores the clinical relevance of diet-induced acid retention in children and highlights the potential for prevention through dietary modifications, particularly by increasing fruit and vegetable intake alongside appropriate protein consumption.

Food waste: analysis of the complex and variable composition of a promising feedstock for valorisation

There are global concerns about the environmental, social, and economic consequences associated with the generation of food waste. To effectively address this challenge, and particularly to develop food waste valorisation approaches, it is necessary to acquire understanding of the physicochemical and biochemical characteristics of food waste. This study comprises a systematic overview and quantitative assessment of the characteristics of food waste biomass, and this was achieved through a comprehensive literature review. The resulting database encompasses the physicochemical, biochemical, and elemental composition of food waste. The study evaluates food waste variability, analyses correlations between components, and highlights patterns in composition. Overall, food waste is a rather variable material. Typology, collection source and geographical origin of food waste streams are the main contributing factors to variation in physicochemical, biochemical and elemental compositions of food waste, while collection season and storage temperature appear not to be contributing substantially to variation. A clear distinction between plant-based and animal-based food waste biomass can be observed with animal-matter enriched food waste having high contents of protein, lipid and ash, but a low starch content. On the other hand, plant-based food waste can be either high in lignin and low in starch or high in carbohydrates, starch and higher heating value. Fibre content appears an indicative parameter, distinguishing plant from animal enriched food waste, and correlating strongly with lignin-rich, starch-poor plant biomass. The heterogeneity of food waste biomass composition will create challenges in developing and scaling up appropriate food waste management. The current study shows that the analysis of specific food waste parameters, such as fibre content, can be used, to inform the choice of the most appropriate valorisation route.

Breeding wheat for organic farming: can the high grain protein gene Gpc-B1 help to tackle challenges in view of end-use quality?

Organic farming contributes to sustain healthy ecosystems, but challenges such as lower crop yields and supply of the nitrogen needs of crops remain. Wheat is the most important organic arable crop in Europe and grain protein content is the main quality trait also for grading organic wheat despite that high baking quality can be also realized at lower protein contents. Hence, breeding of organic wheat varieties that realize a stable high grain protein content even at lower nitrogen availability is of utmost importance to guarantee income of organic wheat growers. A major QTL for high grain protein content was identified in wild emmer and transferred into bread wheat. We tested six different wheat genetic backgrounds varying for the presence/absence of the functional Gpc-B1 allele in multi-location trials in Central Europe for their performance under organic growing. The increase in grain protein content caused by the functional Gpc-B1 allele was present in almost all genetic backgrounds, however, was not consistent across all tested quality traits. None the less, the functional Gpc-B1 allele may play a major role to increase the stability of organic wheat to reach minimum requirements by traders and processors with respect to grain protein content.

Oil–water interfacial behaviour of different caseins and stability of emulsions: Effect of micelle content and caseins concentrations

This study aimed to investigate the interfacial behaviour of caseins in different micelle content and its effect on the stability of emulsions, including micellar casein concentrate (MCN), calcium caseinate (CaC) and sodium caseinate (NaC). Results revealed that at high protein concentrations (0.5 %–2.5 %), MCN, CaC and NaC exhibited similar interfacial behaviour as well as unfolding rate constants (k1) of 3.11–3.41 × 10−4 (s−1), 2.96–3.35 × 10−4 (s−1) and 2.75–3.27 × 10−4 (s−1), respectively. The interfacial layer formed was dominated by non-micelles, and microscopic images revealed the thickness of the interfacial layer to be 10–20 nm. By contrast, at low concentrations, the differences in the slope of E–π curves and k1 indicated that the micelle content of casein affects protein interfacial behaviour and properties and that micellar casein is involved in the formation of the interfacial layer. The formation of large numbers of droplets during emulsion preparation results in a similar low concentration environment. Cryo-TEM showed adsorption of micellar casein in all three casein-stabilised emulsions, and the amount of adsorption was proportional to the micelle content. NaC has faster adsorption and rearrangement rates due to fewer micelles and more non-micelles, so that NaC forms smaller droplets and more stable emulsions than those formed by MCN and CaC within the range of 0.5 % to 2.0 %.

Influence of extruded soybean meal with different fat contents and varying oleic acid content on floating fish feed quality and composition

Soybean meal (SBM) is the most widely used source of high-quality plant protein within the feed industry. Raw soybeans are conventionally processed to reduce antinutritional factors, enhance protein bioavailability and improve the overall quality of the final feed product. New high-oleic (HO) cultivars with enhanced unsaturated fatty acids are being utilized in the production of HO SBM for use in the animal feed industry. However, no studies to date have examined the impact of HO SBM on feed formulation and processing of aquaculture feeds. Therefore, we aimed to determine the quality of feed for juvenile domesticated striped bass (Morone saxatilis) using SBM prepared from HO or normal-oleic (NO) soybeans and extrusion-expeller processing. The following four soybean meals were used in our experimental diets: solvent-extracted defatted normal oleic (SENO), full-fat normal oleic (FFNO), extruded-expelled defatted normal oleic (EENO), or full-fat high oleic (FFHO). These meals replaced half of the fishmeal (FM) normally included in a nutritionally complete marine finfish diet. Physico-chemical feed variables and chemical composition were determined during feed production. Data were analyzed using one-way ANOVA and means were separated using Tukey’s t-test. The specific mechanical energy of the diet was reduced with the addition of full-fat SBMs during the extrusion process. All finished fish diets were of similar high quality with high pellet durability index and protein content (P > 0.05). This suggested that using different types SBM, including high oleic, to replace 50 % of the fish meal in a floating feed for juvenile domesticated striped bass does not adversely affect the feed quality or nutritional content.

A comparative analysis of crustacean exoskeletons: structural, microstructural, morphological, and UV absorption studies

This study aims to investigate the structural, thermal, and spectral characteristics, along with the ultra-violet (UV) absorption of various marine benthos exoskeletons, such as various species of crabs (Portunus sanguinolentus, Portunus pelagicus, Charybdis feriata) and mantis shrimp (Oratosquilla oratoria). Their unique properties and ability to survive in harsh oceanic environments make them interesting research subjects. This research utilized powder x-ray diffraction (XRD) analysis to determine the crystal structure of the benthic varieties. The sample surface was analyzed using high-resolution micrographs obtained from field-emission scanning electron microscopy (FESEM), which identified the presence of chitin and calcite in the marine benthos. This was further confirmed by differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FTIR). The optical characteristics were investigated using UV-visible spectroscopy. The proximate analysis revealed high protein content in the mantis shrimp exoskeleton compared to other crab species, highlighting its excellent UV absorption characteristics. Overall, this research has the potential to broaden our understanding of marine organisms, which can have potential applications in biotechnology and materials science to develop nature-inspired innovative materials sustainably.

Hydrodynamics and Aggregation of Nanoparticles with Protein Corona: Effects of Protein Concentration and Ionic Strength.

Multiple 10nm-sized anionic nanoparticles complexed with plasma proteins (human serum albumin (SA) or immunoglobulin gamma-1 (IgG)) at different ratios are simulated using all-atom and coarse-grained models. Coarse-grained simulations show much larger hydrodynamic radii of individual particles at a low protein concentration (a protein-to-particle ratio of 1) than at high protein concentrations or without proteins, indicating particle aggregation only at such a low protein concentration, in agreement with experiments. This particle aggregation is attributed to both electrostatic and hydrophobic particle-protein interactions, to an extent dependent on different proteins. In all-atom simulations, IgG proteins induce particle aggregation with and without salt, while SA proteins promote particle aggregation only in the presence of salt that can weaken the electrostatic repulsion between anionic particles closely linked via SA that is smaller than IgG, which also agree well with experiments. Besides charge interactions, hydrophobic interactions between particles and proteins are also important especially at the high salt concentration, leading to the increased particle-protein contact area. These findings help explain experimental observations regarding that the effects of protein concentration and ionic strength on particle aggregation depend on different plasma proteins, which are interpreted by binding free energies, electrostatic, and hydrophobic interactions between particles and proteins.

Identification of Drought Tolerant Chickpea Genotypes under Simulated Drought

Chickpea (Cicer arietinum L.) is one of the most important legume crops worldwide, with high protein content. Chickpea productivity is highly threatened by abiotic stresses, of which drought exerts the most crucial role in terms of growth inhibition and yield losses encountered. Since germination is a critical stage that is negatively affected by drought, an experiment was conducted to estimate the genotypic variability among 27 chickpea genotypes and to determine the seed germination and seedling growth ability under water stress conditions. Seeds were subjected to water stress by using polyethylene glycol (PEG-6000) at five stress levels (0, 5, 10, 15 and 20 % PEG). Among the genotype DIBG 205 (94.50%) recorded highest germination percentage compared to other genotypes. Root length recorded was highest in ICCV 4958 (18.48 cm) under 10% PEG -6000 and decreased with increase in osmotic stress. Drought significantly affected germination as well as all other associated traits with the effects of stress being analogous to the stress level applied. Seedling vigour index is a suitable selection criterion for drought tolerance, high seedling vigour index was observed in DIBG 205 and ICCV 4958 showing increased drought tolerance at high stress level, whereas low seedling vigour index was recorded in ICCV 201217 and ICCV 201116 indicating their possible exploitation as valuable genetic material for further breeding programs for drought tolerance.