Search Results (35)

Microbial fermentation represents an interesting strategy for the management and valorization of agro-industrial byproducts. In this study, the proteolytic strain Bacillus sp. CL18 was used to produce bioactive hydrolysates during submerged cultivation with various protein-containing substrates, including byproducts from the poultry (feathers), cheese (whey), fish (scales), and vegetable oil (soybean meal) industries. The bioactive feather hydrolysates (BFHs) showing high antioxidant activity were incorporated in poly(vinyl alcohol) (PVA) and poly-ε-caprolactone (PCL) nanofibers by the electrospinning technique. The PVA nanofibers containing 5% BFH reached antioxidant activities of 38.7% and 76.3% for DPPH and ABTS assays, respectively. Otherwise, the PCL nanofibers showed 49.6% and 55.0% scavenging activity for DPPH and ABTS radicals, respectively. Scanning electron microscopy analysis revealed that PVA and PCL nanofibers containing BFH had an average diameter of 282 and 960 nm, respectively. Moreover, the results from thermal analysis and infrared spectroscopy showed that the incorporation of BFH caused no significant modification in the properties of the polymeric matrix. The bioconversion of feathers represents an interesting strategy for the management and valorization of this byproduct. Furthermore, the effective incorporation of BFH in polymeric nanofibers and validation of the biological activity suggest the application of these materials as antioxidant coatings and packaging. Full article

The fodder soybean (Glycine max) is an excellent leguminous forage with a high protein content and hay yield, cultivated comprehensively in alpine regions, but seasonal drought in northern regions severely impacts the growth of seedlings. Melatonin (MT) and strigolactone (SL) are critical in relieving the restraint of plant growth in water-deficient environments, but the mechanisms of MT- and SL-mediated drought resistance in fodder soybean needs to be explored. This study mainly investigated the potential morphophysiological mechanism of MT and SL treatments in protecting fodder soybean from drought stress. The fodder soybean ‘Gongnong 535’ was treated with 100 µM MT or 1 µM SL under normal, moderate, and severe water deficit conditions. The results showed that MT and SL treatments enhanced the plant growth parameters and stomatal aperture under drought stress. Moreover, the observed reductions in superoxide ion (O₂^.-), malondialdehyde (MDA), and relative electrical conductivity (REC), along with enhancements in the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), as well as higher levels of ascorbate (AsA), glutathione (GSH), soluble sugar (SS), soluble protein (SP), and free proline (Pro), indicated that MT and SL application effectively alleviated the oxidative damage and prevented the cell membrane disruption caused by drought stress. Additionally, MT and SL treatments improved photosynthesis and growth in fodder soybean seedlings under water stress by adjusting chlorophyll pigments, gas exchange indexes, and chlorophyll fluorescence parameters, as well as endogenous hormone levels. Simultaneously, MT and SL influenced the expression of genes associated with photosynthesis and antioxidant defenses, as well as phytohormone concentrations. Notably, the protective effect of the SL treatment was superior to that of MT in water-deficient conditions. This study contributes to further understanding the defensive mechanism of MT and SL against drought stress. Full article

This study aimed to assess the effect of the addition (2%) of soybean protein (SP) and insect flours derived from house crickets (Acheta domesticus, HCF) and yellow mealworm (Tenebrio molitor, YMF) in cooked sausages. The technological characteristics of the batter, the chemical composition of the sausages, their technological traits and lipid stability during refrigerated storage, as well as their sensory properties, were investigated. The SP, HCF and YMF batters displayed higher pH (p = 0.0025) and stability (p < 0.0001) but a darker colour (p < 0.0001) than the control samples. The addition of SP increased the plasticity of the batter (p = 0.0017), while YMF decreased its structural strength (p = 0.0274). Higher pH and darker colour were detected in SP-, HCF- and YMF-containing sausages; however, the effect of the alternative proteins depended on the duration of storage. The plasticity decreased in the insect-containing sausages (p = 0.0010) and increased over time (p = 0.0136), whereas the elasticity was lower in the YMF group (p < 0.0001). The protein and fat contents were higher (p < 0.0001) in the sausages containing alternative protein. TBARS content decreased over time in these groups. The HCF and YMF sausages received lower scores for their appearance, colour, texture, flavour and taste, suggesting the need for further technological interventions to make such products more attractive to consumers. Full article

Microbial nitrogen sources are promising, and soy protein as a plant-based nitrogen source has absolute advantages in creating microbial culture medium in terms of renewability, eco-friendliness, and greater safety. Soy protein is rich in variety due to different extraction technologies and significantly different in the cell growth and metabolism of microorganisms as nitrogen source. Therefore, different soy proteins (soy meal powder, SMP; soy peptone, SP; soy protein concentrate, SPC; soy protein isolate, SPI; and soy protein hydrolysate, SPH) were used as nitrogen sources to culture Bacillus subtilis, Streptococcus lactis, and Streptomyces clavuligerus to evaluate the suitable soy nitrogen sources of the above strains. The results showed that B. subtilis had the highest bacteria density in SMP medium; S. lactis had the highest bacteria density in SPI medium; and S. clavuligerus had the highest PMV in SPI medium. Nattokinase activity was the highest in SP medium; the bacteriostatic effect of nisin was the best in SPI medium; and the clavulanic acid concentration was the highest in SMP medium. Based on analyzing the correlation between the nutritional composition and growth metabolism of the strains, the results indicated that the protein content and amino acid composition were the key factors influencing the cell growth and metabolism of the strains. These findings present a new, high-value application opportunity for soybean protein. Full article

Nodule endophytes and associated bacteria are non-symbiotic bacteria that colonize legume nodules. They accompany nodulating rhizobia and can form beneficial associations, as some of them are plant growth-promoting rhizobacteria (PGPR) that are able to promote germination and plant growth and increase tolerance to biotic and abiotic stress. White lupin (Lupinus albus) is a legume crop that is gaining relevance as a suitable alternative to soybean as a plant protein source. Eleven nodule-associated bacteria were isolated from white lupin nodules grown in a Tunisian soil. They belonged to the genera Rhizobium, Ensifer, Pseudomonas and Bacillus. Their plant growth-promoting (PGP) and enzymatic activities were tested in vitro. Strains Pseudomonas sp., L1 and L12, displayed most PGP activities tested, and were selected for in planta assays. Inoculation with strains L1 or L12 increased seed germination and had the same positive effects on all plant growth parameters as did inoculation with symbiotic Bradyrhizobium canariense, with no significant differences among treatments. Inoculation with efficient nitrogen-fixing rhizobia must compete with rhizobia present in the soil that sometimes nodulate efficiently but fix nitrogen poorly, leading to a low response to inoculation. In such cases, inoculation with highly effective PGPR might represent a feasible alternative to boost crop productivity. Full article

The aim of this research was to assess the influence of partially substituting post-extraction soybean meal with distillers dried yeast on the efficiency of broiler chicken fattening and the intestinal microflora.I Inactive distillers dried yeast Saccharomyces cerevisiae, cultivated on wheat extract, was employed in the study. The research was conducted on 112 Ross 308 line cockerels subjected to a 35-day fattening period, during which they were fed Starter (days 1–10), Grower (days 11–27), and Finisher (days 28–35) diets. Broiler chickens were randomly divided into four groups: control and three experimental groups with varying levels of distillers dried yeast—3%, 6%, and 9%. Cockerels in the control group (Starter diet) exhibited higher feed consumption compared to those receiving 3% yeast in their diet. Cockerels in the group receiving 3% yeast (Grower diet) demonstrated better feed conversion compared to those receiving 9% yeast in their diet. The study revealed that regardless of the broiler chicken fattening period, there was a decrease in the overall number of isolated microorganisms in the feces with an increase in the proportion of distillers dried yeast in the diet. This was confirmed by the total number of bacteria, anaerobic bacteria, Enterobacteriaceae, E. coli, Enterococcus sp., and S. aureus. Based on cluster analysis (dendrogram), it was observed that only a 9% addition of yeast to the diet significantly influenced the quantitative and qualitative composition of the fecal microbiota of broiler chickens. In summary, a properly balanced feed with distillery yeast can be used as a good source of energy and protein in feed mixtures for broilers, serving as a cost-effective alternative to soybean meal. However, for optimal production results and feed costs, the inclusion of yeast in the feed should not exceed 3%. Full article

Juvenile rainbow trout (125 ± 0.8 g) were fed a fishmeal control diet (C), a high soy protein concentrate diet (SP), a high soybean meal diet (HiS), or a diet with high levels of fermented soy protein concentrate (fSP) for 12 weeks in a tank system capable of receiving 1st and 3rd use water from a serial-reuse production hatchery. Water quality was generally lower in 3rd use compared to 1st use water and after passing through tanks (inflow vs. outflow). Total dissolved solids were significantly higher (p = 0.003) for 3rd use compared to 1st use water, and values were also higher (p < 0.001) for the fSP diet. Turbidity and ammonia were highest in tanks for trout fed the HiS and fSP and SP and fSP diets, respectively, but were characterized by high variation, which likely prevented the detection of significant differences. Weight gain (p < 0.001) and survival (p = 0.008) were significantly lower for trout in 3rd use compared to 1st use water. Trout fed the HiS diet were generally in poorer physiological condition with lower body fat stores (p = 0.05) and lower growth rate (p < 0.001) and survival (p = 0.05) compared to the other diets, which were similar. The expression of several stress-associated genes (FK506, DIO2, REGPS, Cyp1a, G6PH, GADD45a, and IRF-1) in the liver and gill showed that diet and water source affected their regulation. Replacement of FM by SP providing 50% of dietary protein promotes acceptable growth performance compared to an FM diet and was superior to HiS. The impacts of soy protein concentrate on water quality under commercial production conditions, however, require further study. Full article

Protein is an essential nutrient for laying hens, playing a crucial role in egg production and supporting their overall health. An 8-week feeding trial was conducted on 120 Lohmann Brown laying hens (aged 38 weeks). The layers were assigned randomly to three groups and housed in cages (twenty replicates × two birds/cage). All groups were fed a corn–soybean meal basal diet (2750 kcal/kg metabolizable energy (ME) with 17.8% crude protein (CP)). In contrast to conventional diet (CON), the experimental groups were supplemented primarily at the expense of soybean meal with 2.0% Chlorella vulgaris (CV2%) and 2.0% Spirulina platensis (SP2%). Their high concentrations of chlorophyll a (5.56; 9.06 mg/g), chlorophyll b (0.88; 1.34 mg/g), and antioxidant activity expressed as 2,2-diphenyl-1-picrylhydrazyl (73.29; 81.27 DPPH% inhibition) improved egg yolk quality. At the end of the trial, eighteen eggs/group (six yolk samples/group, three eggs/sample) were collected to determine the egg quality and nutritional parameters (fatty acids profile, cholesterol, β-carotene, yolk color, and antioxidant capacity). To determine the activity of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH), and total antioxidant capacity (TAC), blood samples were collected at the end of the period. Microalgae inclusion increased (p < 0.05) the fatty acid content, ß-carotene concentration (p < 0.001), antioxidant capacity (p < 0.0001), and yolk color intensity (p < 0.001) significantly, especially the yolk redness a* color parameter, but without any significant results concerning cholesterol concentration. Boiling the eggs for 10 min significantly (p < 0.001) increased the b* color parameter on microalgae treatments. The supplementation of laying hens’ diet with microalgae positively influenced egg quality and nutritional properties. Full article

Sucrose metabolism plays a critical role in development, stress response, and yield formation of plants. Sucrose phosphate synthase (SPS) is the key rate-limiting enzyme in the sucrose synthesis pathway. To date, genome-wide survey and comprehensive analysis of the SPS gene family in soybean (Glycine max) have yet to be performed. In this study, seven genes encoding SPS were identified in soybean genome. The structural characteristics, phylogenetics, tissue expression patterns, and cold stress response of these GmSPSs were investigated. A comparative phylogenetic analysis of SPS proteins in soybean, Medicago truncatula, Medicago sativa, Lotus japonicus, Arabidopsis, and rice revealed four families. GmSPSs were clustered into three families from A to C, and have undergone five segmental duplication events under purifying selection. All GmSPS genes had various expression patterns in different tissues, and family A members GmSPS13/17 were highly expressed in nodules. Remarkably, all GmSPS promoters contain multiple low-temperature-responsive elements such as potential binding sites of inducer of CBF expression 1 (ICE1), the central regulator in cold response. qRT-PCR proved that these GmSPS genes, especially GmSPS8/18, were induced by cold treatment in soybean leaves, and the expression pattern of GmICE1 under cold treatment was similar to that of GmSPS8/18. Further transient expression analysis in Nicotiana benthamiana and electrophoretic mobility shift assay (EMSA) indicated that GmSPS8 and GmSPS18 transcriptions were directly activated by GmICE1. Taken together, our findings may aid in future efforts to clarify the potential roles of GmSPS genes in response to cold stress in soybean. Full article

A new member of the DegP-type periplasmic serine endoproteases of the S1C family from the marine bacterium Cobetia amphilecti KMM 296 (CamSP) was expressed in Escherichia coli cells. The calculated molecular weight, number of amino acids, and isoelectric point (pI) of the mature protein CamSP are 69.957 kDa, 666, and 4.84, respectively. The proteolytic activity of the purified recombinant protease CamSP was 2369.4 and 1550.9 U/mg with the use of 1% bovine serum albumin (BSA) and casein as the substrates, respectively. The enzyme CamSP exhibited maximum activity at pH 6.0–6.2, while it was stable over a wide pH range from 5.8 to 8.5. The optimal temperature for the CamSP protease activity was 50 °C. The enzyme required NaCl or KCl at concentrations of 0.3 and 0.5 M, respectively, for its maximum activity. The Michaelis constant (K_m) and V_max for BSA were determined to be 41.7 µg/mL and 0.036 µg/mL min⁻¹, respectively. The metal ions Zn²⁺, Cu²⁺, Mn²⁺, Li²⁺, Mg²⁺, and Ca²⁺ slightly activated CamSP, while the addition of CoCl₂ to the incubation mixture resulted in a twofold increase in its protease activity. Ethanol, isopropanol, glycerol, and Triton-X-100 increased the activity of CamSP from two- to four-times. The protease CamSP effectively degraded the wheat flour proteins but had no proteolytic activity towards soybean, corn, and the synthetic substrates, α-benzoyl-Arg-p-nitroanilide (BAPNA) and N-Succinyl-L-alanyl-L-alanyl-L-prolyl-L-phenylalanine 4-nitroanilide (SAPNA). Full article

Spray-dried plasma (SDP) contain a variety of functional proteins that play an immunomodulatory role. To evaluate the potential of SDP to stimulate the immune system, day-old Ross 708 male broiler chicks (200) were allocated randomly to five dietary treatments. Treatment 1 (CX) comprised chicks fed basal unmedicated corn–soybean meal (SBM) without the addition of SDP. Treatment 2 (MX) includes chicks fed unmedicated corn–SBM basal containing Bacitracin methylene disalicylate (BMD) at 0.055 g/kg diet. Treatments 3 (SDP1), 4 (SDP2), and 5 (SDP3) contained chicks given unmedicated corn–SBM basal, into which SDP was included at 10, 20, and 30 g/kg diet, respectively. On d 7, 14, and 21, chicks’ body weight and FCR were calculated. Additionally, leucocyte counts, oxidative status, and IgY concentrations were determined in blood. On d 23, fecal populations of selected indicator bacteria species were determined. Results showed that FCR for SP3 was superior (p < 0.05) to other treatments. Likewise, heterophil numbers decreased in MX and SDP treatments compared to CX. Circulating IgY concentration was higher for SDP dietary treatments (p < 0.05) compared to MX. In conclusion, dietary SDP at 30 g/kg enhanced immune surveillance by increasing circulating IgY levels, maintaining a normal oxidative state, and increasing gut Bifidobacteria, thereby improving chick growth performance. Full article

Nitric oxide (NO) plays a significant role in plant drought resistance. However, the effects of the exogenous application of NO to crops under drought stress vary within and among species. In this study, we explored the influence of exogenous sodium nitroprusside (SNP) on the drought resistance of soybean leaves in the full flowering stage using two varieties: drought-tolerant HN44 and non-drought-tolerant HN65. Spraying SNP on soybean leaves at the full flowering period under drought stress improved the NO content in soybean leaves. The activities of nitrite reductase (NiR) and nitrate reductase (NR) in leaves were affected by NO inhibition. The activity of antioxidant enzymes in leaves increased with the extension of SNP application time. Contents of osmomodulatory substances, including proline (Pro), soluble sugar (SS), and soluble protein (SP) increased gradually with the extension of SNP application time. The malondialdehyde (MDA) content decreased as the NO content increased, thus reducing membrane system damage. Overall, spraying SNP reduced damage and improved the ability of soybean to cope with drought. This study explored the physiological changes of SNP soybean under drought stress and provided theoretical basis for improving drought-resistant cultivation of soybean. Full article

Soybean meal is a class of by-products obtained from the processing of soybean products. Despite its high nutritional value, the presence of glycoside isoflavones limits human use of soybean meal. This study evaluated the effect of solid-state fermentation (SSF) with different edible mushroom mycelia (Pleurotus ostreatus, Hericium erinaceus, and Flammulina velutipes) on the proximate composition, antioxidant properties, and physicochemical properties of fermented soybean meal powder (SP). The results revealed that fermented SP had a higher nutritional value when compared to SP. P. ostreatus was the most pronounced among the three species. Crude protein content was found to have increased by 9.49%, while the concentration of glutamate and aspartic acid increased by 23.39% and 23.16%, respectively. SSF process significantly increased the total polyphenol content (TPC) and aglycone isoflavone content by 235.9% and 324.12%, respectively, resulting in increased antioxidant activity (evaluated by the DPPH, •OH, ABTS⁺ assays). Microstructural changes in fermented SP and nutrient degradation and utilization were observed. Thus, fermented SP can be used as a raw material with enhanced nutritional properties to develop new functional foods, such as plant-based foods represented by plant meat. It provides a promising approach for increasing the added value of soybean meal. Full article

Several alternative proteins have emerged that may improve the environmental footprint of our food system. Evaluations into the impact of these protein sources on gastrointestinal health is limited. A study was performed to determine whether aqueous extracts from dietary protein sources, both traditional and alternative, had a differential impact on a leaky gut cell culture model. Aqueous extracts of soybean meal, fish meal, Cyberlindnera jadinii, Saccharomyces sp., Bio-Mos, Chlorella pyrenoidosa, Methylobacterium extorquens, Escherichia coli, and Hermetia illucens were administered onto a Caco-2/THP-1 co-culture and the transepithelial electrical resistance (TEER) and IL-1β, IL-6, IL-8, IL-10, TNF-α, CXCL10, and MCP-1 concentrations, and NF-κB activity were determined. Principal components analysis and K means clustering were performed. Three clusters were identified: one for soybean meal, one for bacterial meals, and one for the remaining sources. The bacterial meal cluster exhibited pro-inflammatory properties, i.e., correlated with TNF-α, IL-1β, IL-8, and NF-κB. The soybean meal cluster exhibited both pro- and anti-inflammatory properties, whereas the third cluster containing the remaining proteins exhibited anti-inflammatory properties (correlated with TEER and IL-10). These results suggest that aqueous extracts from yeast proteins contribute more positively, and bacterial proteins contribute the least positively, towards intestinal health in a leaky gut model. Full article

The SPIRAL1 (SPR1) gene family encodes microtubule-associated proteins that are essential for the anisotropic growth of plant cells and abiotic stress resistance. Currently, little is known about the characteristics and roles of the gene family outside of Arabidopsis thaliana. This study intended to investigate the SPR1 gene family in legumes. In contrast to that of A. thaliana, the gene family has undergone shrinking in the model legume species Medicago truncatula and Glycine max. While the orthologues of SPR1 were lost, very few SPR1-Like (SP1L) genes were identified given the genome size of the two species. Specifically, the M. truncatula and G. max genomes only harbor two MtSP1L and eight GmSP1L genes, respectively. Multiple sequence alignment showed that all these members contain conserved N- and C-terminal regions. Phylogenetic analysis clustered the legume SP1L proteins into three clades. The SP1L genes showed similar exon-intron organizations and similar architectures in their conserved motifs. Many essential cis-elements are present in the promoter regions of the MtSP1L and GmSP1L genes associated with growth and development, plant hormones, light, and stress. The expression analysis revealed that clade 1 and clade 2 SP1L genes have relatively high expression in all tested tissues in Medicago and soybean, suggesting their function in plant growth and development. MtSP1L-2, as well as clade 1 and clade 2 GmSP1L genes, display a light-dependent expression pattern. The SP1L genes in clade 2 (MtSP1L-2, GmSP1L-3, and GmSP1L-4) were significantly induced by sodium chloride treatment, suggesting a potential role in the salt-stress response. Our research provides essential information for the functional studies of SP1L genes in legume species in the future. Full article