Total Soluble Protein Content Research Articles

A synergistic catalytic system of keratinases and disulfide reductases for the bioconversion of feather wastes to feed alternative protein

Effective hydrolysis of feather waste by keratinase is an important way to develop high-quality alternative proteins for feed. It has been shown that the reduction of disulfide bonds is the key rate-limiting step in the hydrolysis of feathers by keratinases. However, the reductive activity of keratinase itself is low. In order to increase the reductive activity of the catalytic system, we screened endogenous disulfide reductase from Bacillus subtilis and constructed a synergistic catalytic system, KerZ1/yjbI-S2-P1, consisting of keratinase and disulfide reductase by co-expression optimization. The reductive activity and feather hydrolytic activity of the synergistic system were 5.67-fold and 5-fold higher than the original system. Feathers were hydrolyzed to a higher extent compared with the original system. The total amino acid and soluble protein concentrations in the products increased by 99% and 59%, respectively. This study provides a more environmentally friendly and efficient reduction capability for keratinase to hydrolysis waste feathers, and also demonstrates a new way of alternative protein feedstock mining.

Effects of integrated nutrient management and fertilizers on the yield of baby corn in Punjab's climatic context

The combined impacts of climate change and increased chemical fertilizer use are diminishing soil fertility, thereby reducing agricultural productivity and farmland yield potential. This study investigates the effect of integrated nutrient management on baby corn. Results showed that the highest cob length (14.28 cm) and green fodder yield (45.56 t ha-1) were achieved using elevated levels of nitrogen (160 kg ha-1) and phosphorus (120 kg ha-1), supplemented with zinc (6 kg ha-1) and Azotobacter. Soil nutrient availability was assessed, indicating that treatment with 160 kg N + 100 kg P + 6 kg Zn + Azotobacter results in available nitrogen levels of 277.2 kg ha-1 and the highest organic carbon content (0.26%). Available phosphorus content (ranging from 24.1 to 24.3 kg P ha-1) is observed with 120 kg P. Nutritional quality parameters were also influenced by nutrient levels, with the treatment of 160 kg N + 120 kg P + 6 kg Zn + Azotobacter showing the highest total soluble solids (11.2% brix) and protein content (17.9%). The treatment of 140 kg N + 100 kg P + 6 kg Zn exhibits the maximum fiber content (26.5%). In summary, the study underscores the positive impact of biofertilizers and zinc on fodder yield and soil properties. Integrating biofertilizers and micronutrients is recommended for sustaining agriculture and maintaining soil health over the long term.

Ultrasound-assisted germination of red kidney beans: Enhancements in physicochemical and nutritional profiles

To improve the conventional germination process and improve the nutritional quality of red kidney beans, this study employed high-intensity ultrasound (HIU) supplemented with hydrogen peroxide as a pre-germination treatment. The results showed that the 350 W-10 min treatment yielded the highest germination rate (77.09%), with its sprout length 81.13% greater than that of the control group. The 350 W-10 min treatment increased total protein, soluble protein, and ash content, while simultaneously reducing the fat, starch, and soluble sugar content. The HIU treatment accelerated the accumulation of phenolic and flavonoid compounds, ascorbic acid, and γ-aminobutyric acid. The 350 W-10 min treatment also decreased the levels of phytic acid, trypsin inhibitor activity, and tannin by 42.71%, 65.58%, and 53.18%, respectively. Furthermore, ultrasonic cavitation enhanced antioxidative capacity and improved amino acid composition and protein digestibility. Consequently, HIU serves as a cost-efficient method to accelerate the germination process and enhance their nutritional composition.

Reponses of morphological and biochemical traits of bamboo trees under elevated atmospheric O3 enrichment

Dwarf bamboo (Indocalamus decorus) is an O3-tolerant plant species. To identify the possible mechanism and response of leaf morphological, antioxidant, and anatomical characteristics to elevated atmospheric O3 (EO3) concentrations, we exposed three-year-old I. decorus seedlings to three O3 levels (low O3-LO: ambient air; medium O3-MO: Ambient air+70 ppb high O3–HO: Ambient air+140 ppb O3) over a growing season using open-top chambers. Leaf shape and stomatal characteristics, and leaf microscopic structure of I. decorus were examined. The results indicated that 1) the stomata O3 flux (Fst) of HO decreased more rapidly under EO3 as the exposure time increased. The foliar O3 injury of HO and MO occurred when AOT40 was 26.62 ppm h and 33.20 ppm h, respectively, 2) under EO3, leaf number, leaf mass per area, leaf area, and stomata length/width all decreased, while leaf thickness, stomatal density, width, and area increased compared to the control, 3) MDA and total soluble protein contents all showed significantly increase under HO (36.57% and 32.77%) and MO(31.91% and 19.52%) while proline contents only increased under HO(33.27%). 4) MO and HO increased bulliform cells numbers in the leaves by 6.28% and 23.01%, respectively. HO reduced the transverse area of bulliform cells by 13.73%, while MO treatments had no effect, and 5) the number of fusoid cells interspace, the transverse area of fusoid cells interspace, and mesophyll thickness of HO significantly increased by 11.16%, 28.58%, and 13.42%, respectively. In conclusion, I. decorus exhibits strong O3 tolerance characteristics, which stem from adaptions in the leaf's morphological, structural, antioxidant, and anatomical features. One critical attribute was the enlargement of the bulliform cell transverse area and the transverse area of fusoid cells interspace that drove this resistance to O3. Local bamboo species with high resistance to O3 pollution thus need to be promoted for sustained productivity and ecosystem services in areas with high O3 pollution.

Dietary Variation Effect on Life History Traits and Energy Storage in Neotropical Species of Drosophila (Diptera; Drosophilidae).

The ability of an organism to respond to nutritional stress can be a plastic character under the action of natural selection, affecting several characteristics, including life history and energy storage. The genus Drosophila (Diptera; Drosophilidae) presents high variability regarding natural resource exploration. However, most works on this theme have studied the model species D. melanogaster Meigen, 1830 and little is known about Neotropical drosophilids. Here we evaluate the effects of three diets, with different carbohydrate-to-protein ratios, on life history (viability and development time) and metabolic pools (triglycerides, glycogen, and total soluble protein contents) of three Neotropical species of Drosophila: D. maculifrons Duda, 1927; D. ornatifrons Duda, 1927, both of the subgenus Drosophila Sturtevant, 1939, and D. willistoni Sturtevant, 1916 of the subgenus Sophophora Sturtevant, 1939. Our results showed that only D. willistoni was viable on all diets, D. maculifrons was not viable on the sugary diet, while D. ornatifrons was barely viable on this diet. The sugary diet increased the development time of D. willistoni and D. ornatifrons, and D. willistoni glycogen content. Thus, the viability of D. maculifrons and D. ornatifrons seems to depend on a certain amount of protein and/or a low concentration of carbohydrate in the diet. A more evident effect of the diets on triglyceride and protein pools was detected in D. ornatifrons, which could be related to the adult attraction to dung and carrion baited pitfall as food resource tested in nature. Our results demonstrated that the evolutionary history and differential adaptations to natural macronutrient resources are important to define the amplitude of response that a species can present when faced with dietary variation.

Effect of different storage conditions on grain quality of paddy

The present investigation was carried out to study the physiological and biochemical changes of paddy grain (Oryza sativa L. var. Ranjit) throughout the course of a 12-month storage period, in an effort to determine the ideal storage conditions with the highest potential for storage under climacteric condition of Assam. Freshly harvested seeds of paddy grain (Ranjit) were stored under different storage conditions for a period of twelve months beginning in January. Based on the results of the study, it was found that the easily moisture permeable structures (T2, T3, T6) showed the maximum change in the physiological and biochemical parameters followed by permeable (T1 and T4) and impermeable (T5 and T7). The rate of change in the values of parameters in paddy stored in the prototype of a Grain safe™ in-store dryer (T7) was found slowest and sluggish, and maintained highest mean values amongst all the storage receptacles in respect of germination percentage, seed vigour index, head rice recovery, moisture content, total soluble protein content, starch content, total soluble sugar content, reducing sugar, non-reducing sugar and amylose content. Significant superiority of hermetic storages (T5 and T7) over traditional storage structures (T1, T2, T3, T4 and T6) in Assam irrespective of all the parameters studied was noticed. Hermetic storage was effective at blocking the effects of external humidity fluctuations as well as the spread of fungi and insects. The solar in-store drier was found to be best amongst all storage structures, in all quality aspects of the long-term storage of paddy.

Boosting the resilience to drought of crop plants using wood distillate: A pilot study with lettuce (Lactuca sativa L.)

Increasingly severe drought driven by climate change is harming crop quality and productivity, making it crucial to find nature-based solutions like wood distillate (WD) to aid crops withstand these stressful conditions. This study investigated the effects of WD application on the growth and stress responses of lettuce (Lactuca sativa L.) under drought conditions. The experiment included periodic measurements of plant growth-related parameters and stress indices to evaluate the effectiveness of WD in mitigating drought-induced damage. The results showed a significant increase (13–26 %) in fresh biomass of the aboveground portion of lettuce treated with WD, indicating the potential of WD as a biostimulant to promote plant growth. In addition, treatment with WD led to a significant increase in total soluble protein content (14–28 %), showing a possible positive effect on protein synthesis. The enhancement of anti-radical activity (measured in terms of DPPH) following the application of WD up to 42 % reflected the ability of the plant to scavenge harmful reactive oxygen species and alleviate oxidative stress. The observed reduction (up to 19 % in comparison with control) in MDA content also confirmed the effectiveness of WD in protecting the integrity of plant cell membranes from oxidative damage. Despite the beneficial effects on anti-radical activity, the total content of the antioxidant compounds (phenols and flavonoids) decreased with the use of WD (5–14 %), most likely suggesting complex interactions between WD and the biosynthesis of these secondary metabolites. The study showed the positive effect of WD application on the growth and stress tolerance of lettuce plants under drought conditions. These results can provide new insights into sustainable agricultural practices and the potential application of WD as a nature-based and effective means to improve crop productivity, especially in water scarce areas.

Climate-induced changes in essential oil production and terpene composition in alpine aromatic plants

Alpine regions are biodiversity hotspots for endemic species with unique adaptations to harsh climatic conditions. These adaptations often involve specialized behaviours and metabolism including the production of secondary metabolites that protects plants from environmental stresses. This study examines the impacts of elevated CO2 (eCO2) and combined effects of elevated CO2 and temperature (eCO2+T) on two alpine aromatic herbs, namely Angelica glauca and Nardostachys jatamansi. These species were raised in open-top chambers (OTCs) and treated with elevated CO2 (600 ppm) and temperature (+2.0 °C from control) during 2018 to 2020. The primary (total soluble sugar, starch, total soluble protein, amino acid and proline contents), secondary metabolites (Phenolics, essential oil yield, and components using GC-MS) and antioxidant activities (superoxide dismutase and peroxidase) were measured. Total soluble sugar increased under eCO2, while starch content, total amino acid and total soluble protein initially increased but later declined in response to the treatments. Proline content and antioxidant activities were higher under eCO2 and eCO2+T treatments. Total phenolic content showed both increasing (in A. glauca) and decreasing (in N. jatamansi) responses to eCO2 and eCO2+T treatments. GC–MS analysis showed decreased monoterpenes in CO2 and temperature treatments, but some sesquiterpenes showed mixed responses with both increases and decreases. These findings suggest that changes in climate can alter the composition of secondary metabolites in alpine herbs, potentially affecting their therapeutic properties and suitability for use in herbal medicine. This study provides valuable insights into the species-specific physiological responses of plants to changing climate.

The impact of multiple abiotic stresses on ns-LTP2.8 gene transcript and ns-LTP2.8 protein accumulation in germinating barley (Hordeum vulgare L.) embryos.

Abiotic stresses occur more often in combination than alone under regular field conditions limiting in more severe way crop production. Stress recognition in plants primarily occurs in the plasma membrane, modification of which is necessary to maintain homeostasis in response to it. It is known that lipid transport proteins (ns-LTPs) participate in modification of the lipidome of cell membranes. Representative of this group, ns-LTP2.8, may be involved in the reaction to abiotic stress of germinating barley plants by mediating the intracellular transport of hydrophobic particles, such as lipids, helping to maintain homeostasis. The ns-LTP2.8 protein was selected for analysis due to its ability to transport not only linear hydrophobic molecules but also compounds with a more complex spatial structure. Moreover, ns-LTP2.8 has been qualified as a member of pathogenesis-related proteins, which makes it particularly important in relation to its high allergenic potential. This paper demonstrates for the first time the influence of various abiotic stresses acting separately as well as in their combinations on the change in the ns-LTP2.8 transcript, ns-LTP2.8 protein and total soluble protein content in the embryonal axes of germinating spring barley genotypes with different ns-LTP2.8 allelic forms and stress tolerance. Tissue localization of ns-LTP2.8 transcript as well as ns-LTP2.8 protein were also examined. Although the impact of abiotic stresses on the regulation of gene transcription and translation processes remains not fully recognized, in this work we managed to demonstrate different impact on applied stresses on the fundamental cellular processes in very little studied tissue of the embryonal axis of barley.

Mechanism of the Synergistic Toxicity of Ampicillin and Cefazoline on Selenastrum capricornutum.

Ampicillin (AMP) and cefazolin (CZO) are commonly used β-lactam antibiotics which are extensively globally produced. Additionally, AMP and CZO are known to have relatively high ecotoxicity. Notably, the mix of AMP and CZO creates a synergistic effect that is more harmful to the environment, and how exposure to AMP-CZO can induce synergism in algae remains virtually unknown. To yield comprehensive mechanistic insights into chemical toxicity, including dose-response relationships and variations in species sensitivity, the integration of multiple endpoints with de novo transcriptomics analyses were used in this study. We employed Selenastrum capricornutum to investigate its toxicological responses to AMP and CZO at various biological levels, with the aim of elucidating the underlying mechanisms. Our assessment of multiple endpoints revealed a significant growth inhibition in response to AMP at the relevant concentrations. This inhibition was associated with increased levels of reactive oxygen species (ROS) and perturbations in nitrogen metabolism, carbohydrate metabolism, and energy metabolism. Growth inhibition in the presence of CZO and the AMP-CZO combination was linked to reduced viability levels, elevated ROS production, decreased total soluble protein content, inhibited photosynthesis, and disruptions in the key signaling pathways related to starch and sucrose metabolism, ribosome function, amino acid biosynthesis, and the production of secondary metabolites. It was concluded from the physiological level that the synergistic effect of Chlorophyll a (Chla) and Superoxide dismutase (SOD) activity strengthened the growth inhibition of S. capricornutum in the AMP-CZO synergistic group. According to the results of transcriptomic analysis, the simultaneous down-regulation of LHCA4, LHCA1, LHCA5, and sodA destroyed the functions of the photosynthetic system and the antioxidant system, respectively. Such information is invaluable for environmental risk assessments. The results provided critical knowledge for a better understanding of the potential ecological impacts of these antibiotics on non-target organisms.

Metabolic alterations in cowpea submitted to water stress

Cowpea is a leguminous plant belonging to the fabaceae family cultivated in the North and Northeast regions of Brazil, with productive potential. Among the abiotic factors, water deficiency is one of the main environmental limitations that influence agricultural production in the world. The objective was to evaluate changes in carbon and nitrogen metabolism in cowpea plants exposed to water deficit. The experiment was conducted in a greenhouse at the Universidade Federal Rural da Amazônia (UFRA, Belém, PA), cowpea plants BR-17 Gurguéia Vigna unguiculata (L.) Walp were used. The experimental design was completely randomized (DIC) in a 2 x 2 factorial scheme, two water conditions (control and water deficit) and two times of stress (four and six days of water suspension), with 7 replications, totaling 28 experimental units. Changes in the metabolism of cowpea plants were evident, with alterations in the activity of the nitrate reductase enzyme, concentrations of total soluble proteins, soluble amino acids, free ammonium and nitrate in the leaf tissue and roots.

Physiological evaluation of Handroanthus impetiginosus (Mart. ex DC.) Mattos seedlings subjected to water deficit

The objective of this work was to evaluate the physiological conditions of H. impetiginosos seedlings in terms of biochemical and hydric aspects in a greenhouse. The seedlings were placed in three-liter pots, composed of soil and chicken manure (3:1). The plants were submitted to the following treatments: control (irrigated once a day) and water deficit (10, 20 and 30 days of water suspension). Biochemical analyzes were performed such as: sucrose, soluble carbohydrates, soluble amino acids, soluble proteins, starch, proline and glycine-betaine. The experimental results were submitted to analysis of variance (ANOVA), Tukey's test and statistical analysis using the SWNTIA program. The concentrations of free amino acids, soluble carbohydrates, sucrose, glycine-betaine and proline increased in leaves and roots of plants subjected to water stress when compared to control plants. On the other hand, there was a reduction in the concentration of total free starch and soluble proteins. Therefore, the higher concentration of soluble carbohydrates and proline indicate their availability to H. impetiginosus plants, helping physiological processes such as photosynthesis, stomatal opening and expansion growth in dry conditions.

Improvement in yield and quality of okra (Abelmoschus esculentus) through crop spacing, mulching and irrigation levels in arid regions

The field experiments were conducted during the rainy (kharif) seasons of 2018–19 and 2019–20 at College of Agriculture, Swami Keshwanand Rajasthan Agricultural University, Bikaner, Rajasthan to study the effect of crop spacing, mulching and irrigation levels on yield and quality of okra [Abelmoschus esculentus (L.) Moench]. Experiment was laid out in split plot design (SPD) with four irrigation levels [40, 60, 80 and 100% pan evaporation (PE)] in the main plot. Two crop geometries (normal sowing and paired row sowing) and three mulches (no mulch, straw and plastic mulch in black colour) were used in the sub-plot and sub-sub-plot, respectively. The study found that using 40% of PE for irrigation led to the shortest time to first flowering (41.72 days). However, the highest fruit yield, leaf area index (LAI), total soluble solids (TSS), protein content and cost-benefit ratio (B:C ratio) were achieved when irrigating at 100% PE followed by 80% PE. Water use efficiency (WUE) was highest (17.24 kg/ha/mm) at 40% PE irrigation level. The highest fruit yield of 153.1 g/plant and 122.4 q/ha was achieved when straw mulch was applied. Considering the combined data, it's worth mentioning that the B:C ratio was significantly greater when utilizing 100 PE irrigation without mulch. Conversely, WUE at 19.1 kg/ha/mm, showed a significant increase when employing 40% PE irrigation along with straw mulch. Therefore, the study demonstrates that utilizing paired row sowing with straw mulch and irrigation at 100% PE resulted in the highest growth attributes, fruit quality of okra and B:C ratio.

Amelioration of salt stress effects on the morpho-physiological, biochemical and K/Na ratio of Vicia faba plants by foliar application of yeast extract

Salinity is one of the most severe environmental stresses that negatively affects field crops’ development and biochemical properties on a widespread global scale. Consequently, aiming to reduce the negative impact of salinity on plants, the objective of the current work was to study the effect of foliar spraying with two doses of yeast extract (2 and 4 g/L) on improving the growth of Vicia faba plants under NaCl stress (100 mM). The recorded results indicated that 100 mM NaCl level significantly decreased all investigated growth metrics (shoot height, root length, number of leaves, leaf area, fresh and dry weights of shoot and roots). Likewise, concentration of chloroplast pigments and the contents of total soluble protein and sugars were reduced in salt stressed faba bean leaves. Nevertheless, data revealed that V. faba plants grown under NaCl stress and sprayed with yeast extract had better growth behavior than those unsprayed. It was found that yeast extract treatment had the ability to induce significant recovery for the reduction occurred in vegetative growth of V. faba plants which exposed to salinity stress by more enhancement of pigment, total soluble protein and sugars contents. Among the yeast extract doses, 2 g/L significantly improved plant growth, biochemical traits and exposed high Mg, K, P content and K/Na ratio in V. faba plants grown under saline stress. It was found that treating V. faba plants with yeast extract can significantly restore the loss of vegetative growth caused by salt stress.

Effect of salinity stress and surfactant treatment with zinc and boron on morpho-physiological and biochemical indices of fenugreek (Trigonella foenum-graecum)

Micronutrient application has a crucial role in mitigating salinity stress in crop plants. This study was carried out to investigate the effect of zinc (Zn) and boron (B) as foliar applications on fenugreek growth and physiology under salt stress (0 and 120 mM). After 35 days of salt treatments, three levels of zinc (0, 50, and 100 ppm) and two levels of boron (0 and 2 ppm) were applied as a foliar application. Salinity significantly reduced root length (72.7%) and shoot length (33.9%), plant height (36%), leaf area (37%), root fresh weight (48%) and shoot fresh weight (75%), root dry weight (80%) and shoot dry weight (67%), photosynthetic pigments (78%), number of branches (50%), and seeds per pod (56%). Fenugreek’s growth and physiology were improved by foliar spray of zinc and boron, which increased the length of the shoot (6%) and root length (2%), fresh root weight (18%), and dry root weight (8%), and chlorophyll a (1%), chlorophyll b (25%), total soluble protein content (3%), shoot calcium (9%) and potassium (5%) contents by significantly decreasing sodium ion (11%) content. Moreover, 100 ppm of Zn and 2 ppm of B enhanced the growth and physiology of fenugreek by reducing the effect of salt stress. Overall, boron and zinc foliar spray is suggested for improvement in fenugreek growth under salinity stress.

Year-long evaluation of total soluble proteins in the trunk of two pine species from northeastern Mexico

Objective: To quantify the one-year total soluble protein (TSP) concentration in the trunk of two pine species.
 Design/Methodology/Approach: The Bradford method (1976) was used to determine the TSP concentration in the two pine species. Statistical tests were subsequently performed with the IBM SPSS 18 Software, using a general linear model (GLM) univariate analysis.
 Results: The TSP concentration was different for each month. The highest concentration was recorded in August (6.84 mg gMS-1 for Pinus pinceana Gordon and 6.82 mg gMS-1 for Pinus cembroides Zucc), and the lowest was registered in April (5.53 mg gMS-1 for Pinus cembroides Zucc) and February (6.64 mg gMS-1 for Pinus pincenana Gordon).
 Study Limitations/implications: There is a lack of information regarding these two pine species and scarce studies explain the behavior of the TSP.
 Conclusions: The concentration of total soluble proteins varies in each month of the year. Further studies that include more plant organs are required to obtain a broader protein profile for both species.

Salicylic Acid with Humic Acid Addition as Potential Hallmarks for Alleviating Drought Stress in Maize Crop and Enhancing Soil Health

Climate change is the biggest concern to the human kind and threat to agri-food security. Deficiency of water in soil and the ability of plants to uptake water is slowed down due rising temperature and microbial imbalance in soil. Salicylic acid plays an important role in mitigating drought stress and improves the overall production of crop. Humic acid is another amendment to cope against water stress and optimizes the yield. Apart from that, there is little known about their impact on soil geochemistry and that how soil health is altered.
 To investigate the effect of salicylic acid and humic acid on the drought experiment was conducted at University Research Farm (URF), PMAS Arid Agriculture University, Rawalpindi during summer 2023. The experiment was set up in randomized complete block design in two factorial arrangements with four replications. The first factor was comprised of mitigation strategies; salicylic acid, humic acid and chemical fertilizer, while second factor was water regimes; water stress and irrigation maintaining 60% field capacity.
 Plant attributes including chlorophyll content (SPAD value), total soluble protein content (mg/g), total free amino acid (mg/g), K+ content (mg/g), Na+ content (mg/g), 1000 grain weight (g) and grain yield (kg/ha) were measured and reported. On the other hand, soil parameters that were estimated are: soil pH, soil organic matter content (%), available N (ppm), available P (ppm), available K (ppm) and cation exchange capacity (cmol/kg).
 According to the data analysis, all of the features under study had a substantial impact from the mitigation approaches. The increased value of chlorophyll content (49.11 mg/g) was obtained in water stressed condition by the application of salicylic acid. Under water stressed regime and salicylic acid boosted the total soluble protein content (1.67 mg/g) and total free amino acid (31.93 mg/g) while grain yield (9451.7 kg/ha) was also boosted up by the amendment salicylic acid in maize. There was also increase in the values of soil pH (6.78), CEC (54.37 cmol/kg), SOM content (0.87%), available N (3.24 ppm), available P (26.14 ppm) and available K (211.23 ppm) drought conditions with the implementation of salicylic acid.
 Humic acid also positively impacted the drought stress and improved the maize yield (8436.2 kg/ha) under drought condition. Similarly, soil nutrient retention is also improved to large extent under water stress state; SOM content (0.49%), available N (2.36 ppm), available P (15.67 ppm) and available K (171.94 ppm).
 Overall, the study showed that amendment of salicylic acid and humic acid, is the greatest strategy to increase crop production and quality while also improving the health of the soil.

Elucidating the effect of TiO2 nanoparticles on mung bean rhizobia via in vitro assay: Influence on growth, morphology, and plant growth promoting traits.

Titanium dioxide nanoparticles (TiO2 NPs) are among the most commonly used nanomaterials and are most likely to end up in soil. Therefore, it is pertinent to study the interaction of TiO2 NPs with soil microorganisms. The present in vitro broth study evaluates the impacts of low-dose treatments (0, 1.0, 5.0, 10.0, 20.0, and 40.0 mg L-1 ) of TiO2 NPs on cell viability, morphology, and plant growth promoting (PGP) traits of rhizobia isolated from mung bean root nodule. Two types of TiO2 NPs, that is, mixture of anatase and rutile, and anatase alone were used in the study. These TiO2 NPs were supplemented in broth along with a multifunctional isolate (Bradyrhizobium sp.) and two reference cultures. The exposure of TiO2 (anatase+rutile) NPs at low concentrations (less than 20.0 mg L-1 ) enhanced the cell growth, and total soluble protein content, besides improving the phosphate solubilization, Indole-3-acetic acid (IAA) production, siderophore, and gibberellic acid production. The TiO2 (anatase) NPs enhancedexopolysaccharide (EPS) production by the test rhizobial cultures. The radical scavenging assay was performed to reveal the mode of action of the nano-TiO2 particles. The study revealed higher reactive oxygen species (ROS) generation by the TiO2 (anatase) NPs as compared with TiO2 (anatase+rutile) NPs. Exposure to TiO2 NPs also altered the morphology of rhizobial cells. The findings suggest that TiO2 NPs could act as promoters of PGP traits of PGP bacteria when applied at appropriate lower doses.

Proline-mediated redox regulation in wheat for mitigating nickel-induced stress and soil decontamination

Nickel (Ni) is known as a plant micronutrient and serves as a component of many significant enzymes, however, it can be extremely toxic to plants when present in excess concentration. Scientists are looking for natural compounds that can influence the development processes of plants. Therefore, it was decided to use proline as a protective agent against Ni toxicity. Proline (Pro) is a popularly known osmoprotectant to regulate the biomass and developmental processes of plants under a variety of environmental stresses, but its role in the modulation of Ni-induced toxicity in wheat is very little explored. This investigation indicated the role of exogenously applied proline (10 mM) on two wheat varieties (V1 = Punjab-11, V2 = Ghazi-11) exposed to Ni (100 mg/kg) stress. Proline mediated a positive rejoinder on morphological, photosynthetic indices, antioxidant enzymes, oxidative stress markers, ion uptake were analyzed with and without Ni stress. Proline alone and in combination with Ni improved the growth, photosynthetic performance, and antioxidant capacity of wheat plants. However, Ni application alone exhibited strong oxidative damage through increased H2O2 (V1 = 28.96, V2 = 55.20) accumulation, lipid peroxidation (V1 = 26.09, V2 = 38.26%), and reduced translocation of macronutrients from root to shoot. Application of Pro to Ni-stressed wheat plants enhanced actions of catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), and total soluble protein (TSP) contents by 45.70, 44.06, 43.40, and 25.11% in V1, and 39.32, 46.46, 42.22, 55.29% in V2, compared to control plants. The upregulation of antioxidant enzymes, proline accumulation, and uptake of essential mineral ions has maintained the equilibrium of Ni in both wheat cultivars, indicating Ni detoxification. This trial insight into an awareness that foliar application of proline can be utilized as a potent biochemical method in mitigating Ni-induced stress and might serve as a strong remedial technique for the decontamination of polluted soil particularly with metals.

The process of pollen transformation into bee bread: changes in bioactivity, bioaccessibility, and microbial dynamics.

Bee pollen and bee bread go hand in hand with health-promoting functional food consumption. Although many studies report high bioactivities of those products, the biotransformation of pollen into bee bread has not been fully understood. Limited findings are available about polyphenol bioaccessibility and microbiological interactions during the fermentation process. This study evaluated the microbial flora, antioxidant properties, and polyphenol and soluble protein bioaccessibility of pollen and bee bread harvested from the same apiary over a certain timeline. Total phenolic content, antioxidant activity and soluble protein content were reported using an in vitro digestion model involving post-gastric, serum-available, and colon-available fractions. The results obtained with the in vitro digestion model refer to the effect of the harvesting period on greater bioaccessibility of polyphenols in bee bread than in pollen at the same apiary. Lactic acid bacteria and yeast found in the samples were mostly identified as Lactobacillus kunkeei, Leuconostoc pseudomesenteroides, and Candida magnoliae using matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS). The discrimination between the pollen and bee bread samples collected in the same apiary and at different harvesting periods was also revealed by Principal Component Analysis (PCA). A harvesting time-based approach was applied to the biotransformation process of pollen and bee bread, and insights into microbial dynamics and bioaccessibility were revealed for the first time under the same beehive conditions.