Search Results (824)

Poly(ε-caprolactone) (PCL) is a biodegradable aliphatic polyester with applications in many areas. Lipase B from Moesziomyces antarcticus (CALB, previously known as Candida antarctica lipase B) is a well-characterize enzyme capable of hydrolysing several polyesters. In this study, the codon-optimized gene encoding CALB was cloned into the yeast Yarrowia lipolytica to enhance its natural capabilities toward polyesters biodegradation. PCL films biodegradation was conducted directly in the medium using the engineered yeast at 28 °C. Process optimization employing baffled flasks significantly improved degradation efficiency and reduced time to 24 h. This study showed that the engineered yeast Y. lipolytica is a promising host for polyester biodegradation. Full article

In our preliminary work, a clam sauce prepared by fermentation with Aspergillus oryzae 3.042 (AO) exhibited desirable flavor and quality; however, the process was prolonged (exceeding 30 d), and a high salt concentration (6–15%) was necessary to prevent spoilage. Consequently, shortening production cycle and reducing salt content without compromising product quality became a new objective. Enzymatic hydrolysis has long been recognized as an efficient approach in seasoning production, with enzyme efficacy being a key competitive factor. Accordingly, an AO-derived aminopeptidase–protease complex (AOAP) was optimized and prepared as a preparatory step. In this study, AOAP was applied to hydrolyze clam meat to evaluate its potential for producing a seasoning base. A two-step enzymatic hydrolysis process was employed. In the first step, the highest hydrolysis degree (29.1%) was achieved using alkaline protease (AP). The resulting hydrolysate was subsequently subjected to secondary hydrolysis with AOAP, achieving a degree of hydrolysis as high as 49.8%. Sensory evaluation revealed a significant reduction in bitterness and enhancement of umami in the final hydrolysate, a finding corroborated by electronic tongue analysis. Further characterization via LC-MS and amino acid (aa) analysis showed that a substantial number of bitter and umami peptides were released following AP treatment; however, the number of these peptides was markedly reduced after a subsequent AOAP hydrolysis, with concurrent substantial changes in the peptide profile. In the two-step hydrolysate, umami peptides mostly contain 3–10 aa, whereas bitter peptides typically contain only 3–5 aa. The content of free aa increased from 369.17 mg/100 g in the control to 3026.25 mg/100 g in the two-step hydrolysate, half of which were bitter, indicating the debittering efficiency of AOAP. Electronic nose analysis revealed similar flavor profile and characteristic presence of nitrogen oxides in all hydrolysates. GC-MS analysis further demonstrated that, after combined enzymatic hydrolysis, the short-chain aldehydes and ketones responsible for the fishy odor in the raw material almost completely disappeared, while long-chain aldehydes with pleasant aromas were generated. These findings suggest that the secondary hydrolysis step using AOAP can effectively improve the overall flavor profile of the clam hydrolysate, which may support its potential applicability in seasoning production, though further optimization and scale-up validation are needed. Full article

The strategic recycling of fish processing byproducts as functional materials has attracted increasing attention for sustainable development and human health. In this study, we investigated the dermatological impact of chum salmon (Oncorhynchus keta) byproduct enzyme hydrolysates (OKPE) administered as a dietary supplement in mice. After eight weeks of OKPE administration, epidermal integrity was improved, as evidenced by a significant attenuation of transepidermal water loss (TEWL). These phenotypic improvements were associated with the regulation of aquaporin-mediated water transport, hyaluronan metabolism, and epidermal differentiation programs. Furthermore, OKPE intake promoted accelerated collagen biosynthesis. Amino acid profiling revealed that OKPE is uniquely enriched in residues essential for both natural moisturizing factor (NMF) synthesis and collagenous scaffold formation. Collectively, these findings suggest that OKPE has potential as a functional food ingredient for reinforcing the skin barrier and improving skin hydration. Full article

This study investigated the replacement of squid-liver powder (SLP) with different marine protein hydrolysates in diets for Pacific white shrimp (Litopenaeus vannamei) over an eight-week feeding period. A control diet contained 5% SLP, whereas four test diets replaced 1% of the diet (dry-matter basis) with tuna hydrolysate liquid (TH), shrimp hydrolysate powder (SH), fish hydrolysate powder (FH), or salmon silage liquid (SS), with soybean meal adjusted to maintain dietary protein balance. Shrimp fed the TH diet showed higher final body weight (15.76 ± 0.24 g shrimp⁻¹) and specific growth rate (3.18 ± 0.02% day⁻¹) than those fed the other experimental diets (p < 0.05). TH also increased feed intake (20.96 ± 0.49 g shrimp⁻¹) and was associated with higher trypsin activity (3236 ± 226 unit h⁻¹ mg protein⁻¹) and improved protein digestibility. Histological observations indicated greater hepatopancreatic cell density and increased intestinal villus height in the TH group. In addition, survival of shrimp fed TH (90.0 ± 2.8%) was higher than that observed in the FH and SS groups (p < 0.05), and hemolymph from TH-fed shrimp showed stronger inhibitory activity against Vibrio parahaemolyticus. Overall, among the evaluated hydrolysates, 1% tuna hydrolysate (dry-matter basis) produced the most consistent improvements across growth performance, digestive capacity, and selected health-related indicators, supporting its feasibility as a partial substitute for squid liver powder in shrimp diets. Full article

Indole-3-acetic acid (IAA) is the main natural auxin and a key regulator of plant growth. However, most commercial auxins are synthetically produced from non-renewable resources. Here, we present a minimal synthetic biology platform for microbial IAA production that also serves as a teaching model for genetic circuit design and bioprocess development. We developed codon-optimized versions of the iaaM and iaaH genes, which encode tryptophan 2-monooxygenase and indole-3-acetamide hydrolase, and assembled them into a compact expression cassette in Escherichia coli TOP10. Correct expression of both enzymes was confirmed by SDS-PAGE. The engineered strain was cultivated in a low-cost medium made from avocado seed hydrolysate, an agro-industrial waste, supplemented with tryptophan as a precursor. IAA was quantified using the Salkowski colorimetric assay and further validated by HPLC, reaching approximately 303–313 µg/mL at 48 h, with the medium costing approximately fivefold cheaper locally than traditional LB. The supernatants containing biosynthetic IAA induced root formation in 100% of tobacco leaf explants, outperforming the commercial standard at the same concentration and confirming biological activity. Since this workflow follows the Design–Build–Test–Learn (DBTL) cycle, Design (pathway selection and codon optimization), Build (plasmid assembly), Test (protein expression, metabolite quantification, plant bioassays), and Learn (medium and process optimization), it provides a sustainable production method and an accessible educational platform for synthetic biology. Full article

This work focused on the identification of angiotensin I-converting enzyme (ACE) inhibitory peptides from royal jelly (RJ) proteins and elucidated their inhibition patterns and mechanisms. RJ proteins were analyzed for ACE inhibition potential using in silico tools, and suitable enzymes were selected for peptide release. Hydrolysis conditions were optimized using response surface methodology (RSM), and the resulting peptides were fractionated and purified. Mass spectrometry identified 57 peptides, with seven selected for synthesis based on scoring. IDFDF, DVNFR, and SFHRL showed the highest ACE inhibition, with IC₅₀ values of 16.9 μM, 42.5 μM, and 242.6 μM, respectively. Lineweaver–Burk plots revealed IDFDF as a competitive inhibitor, DVNFR as a non-competitive inhibitor, and SFHRL as a mixed inhibitor. Molecular docking indicated that peptide–ACE interactions were primarily mediated through hydrogen bonds and Zn(II) coordination. This work promotes the sustainable utilization of RJ and the development of ACE inhibitory peptides derived from food sources. Full article

Seaweed bioactive extraction generates de-extracted residual solids that remain carbohydrate-rich but are often underutilized. This study developed an integrated valorization route for Gracilaria fisheri spent biomass to produce fermentable sugars for β-carotene production by Rhodotorula paludigena CM33. Reducing sugar production was optimized using response surface methodology (Box–Behnken design) by varying reaction time, sulfuric acid concentration, and biomass loading at 90 °C. The predicted optimum (47.39 min, 2.50% (w/v) H₂SO₄, and 7.13% (w/v) biomass) yielded 22.41 g/L reducing sugars and was validated experimentally at 22.22 ± 0.19 g/L, indicating that the model reliably predicted reducing sugar production. The optimized condition was scaled up in a 22 L bioreactor with sequential acid hydrolysis followed by enzyme-assisted hydrolysis, increasing reducing sugars from ~30 to ~40 g/L. FTIR and SEM analyses indicated progressive modification of the carbohydrate matrix across processing stages. Batch cultivation of R. paludigena on the hydrolysate showed that ammonium sulfate supplementation significantly increased biomass, whereas β-carotene titers were not significantly different. Repeated-batch operation on non-supplemented hydrolysate sustained production over four cycles with β-carotene titers of 13.75–17.27 mg/L, demonstrating the operational feasibility of the hydrolysate-based system. Overall, this work demonstrates a practical seaweed biorefinery approach to upgrade G. fisheri spent biomass into sugars and carotenoid-rich yeast biomass. Full article

Sea buckthorn leaves are a relatively underutilised component of sea buckthorn processed products; however, various studies have indicated that they possess hypoglycaemic potential. Under alkaline solubilisation and acid-precipitation conditions, the extraction yield of sea buckthorn leaf protein (SLP) reached 19.33%. Trypsin was selected as the hydrolysing enzyme to extract SLPPs-T, with half-maximal inhibitory concentrations (IC₅₀) against α-glucosidase and DPP-IV of 0.1361 ± 0.017 mg/mL and 0.1286 ± 0.012 mg/mL, respectively. UV spectroscopy, Fourier transform infrared spectroscopy, circular dichroism spectroscopy and particle size analysis indicated that the secondary and microstructures of SLP underwent changes following its hydrolysis to SLPPs-T; following separation, purification, sequence identification and computer screening, two novel peptides, PM-8 and VG-11, were obtained; molecular docking, solid-phase synthesis and in vitro experiments confirmed that VG-11 exhibited superior inhibitory activity, with half-maximal inhibitory concentrations (IC₅₀) against α-glucosidase and DPP-IV of 0.3885 ± 0.015 mM and 0.2611 ± 0.021 mM, respectively. In summary, this study explored the potential of sea buckthorn leaf protein as a natural hypoglycaemic product through a combination of computational modelling and experimental methods, thereby significantly enhancing the value of sea buckthorn resources. Full article

Ledum palustre (L. palustre) is widely used in drug development because of its antibacterial and analgesic effects. However, wild L. palustre is often affected by wildfires, resulting in unstable yields. Forest fires represent a major disturbance in northern forest ecosystems and profoundly affect shrub vegetation and its associated rhizosphere microbial communities. In this study, we investigated a fire chronosequence (1991, 2004, 2012, 2017, and 2020) to systematically examine the morphological traits of L. palustre, rhizosphere soil physicochemical properties, and microbial community characteristics and to identify the key drivers underlying these patterns. The results revealed that postfire recovery time significantly influenced the morphological traits of L. palustre. The biomass, branch number, basal diameter, and plant height of the shrubs at the 1991 burned site increased by 270.49%, 36.11%, 79.32%, and 191.36%, respectively (p < 0.05). From unburned soils, 29 bacterial and 29 fungal isolates were obtained, with Bacillus sp. and Oidiodendron sp. being the dominant culturable bacterial and fungal taxa, respectively. With increasing postfire recovery time, soil moisture, total nitrogen, ammonium, nitrate, soil organic carbon, acid phosphatase (AP) and N-acetyl-β-D-glucosaminidase (NAG) activity significantly decreased. Early fire disturbance markedly altered soil microbial abundance and community composition, leading to an overall decrease in bacterial α diversity. The bacterial community structure at the 2020 burn site and the fungal community structure at the 2012 burn site significantly differed. Mantel tests revealed significant positive correlations between branch number and basal diameter (p < 0.01) and significant negative correlations between plant height and stem density (p < 0.001). Soil carbon and hydrolysable nitrogen were significantly positively correlated with AP and NAG activities (p < 0.001). Moreover, soil physicochemical properties significantly shaped soil microbial community structures, with bacterial communities in early postfire sites driven by total carbon and nitrogen (p < 0.05), whereas fungal communities in the 2012 burned site were influenced primarily by β-N-acetylglucosaminidase (BG) activity (p < 0.05). Fire disturbance drives successional changes in the rhizosphere microbial community structure and function by altering the soil nutrient status and enzyme activity, which in turn influences the morphological traits of L. palustre. This study provides a theoretical basis for improving the yield of L. palustre by exploring the variation in rhizosphere microorganisms. Full article

The global burden of hypertension continues to rise, highlighting an urgent need for effective therapeutic strategies. Angiotensin-converting enzyme (ACE) is central to blood pressure regulation, but commonly used synthetic ACE inhibitors often have adverse side effects, spurring the search for safer natural alternatives. The aim of this study was to investigate Yanbian cattle hemoglobin as a novel precursor for ACE inhibitory peptides. The <1 kDa fraction was identified as exhibiting the highest inhibitory activity through the systematic screening of hydrolysates across multiple molecular weight ranges. LC-MS/MS analysis identified 1980 peptides, of which four were selected for further experiments. Solid-phase synthesis confirmed that NFGYDL exhibited the strongest ACE inhibition (IC₅₀ = 54.95 μM). Inhibition kinetics showed FHDYL acted as a mixed-type inhibitor, DLGHF and NFGYDL as competitive inhibitors and GFHLD as a non-competitive inhibitor. Molecular dynamics simulations validated the stable binding of these bovine blood-derived peptides to the ACE complex. HUVEC functional assays demonstrated that four peptides significantly increased angiotensin II-induced nitric oxide production and endothelin-1 levels, suggesting their potential antihypertensive activity. These findings suggested that bovine blood is a promising natural source of ACE-inhibitory peptides and holds potential for application as a functional component in functional foods targeting hypertension management. Full article

The differential effects of thermolysin and four commercial proteases on soy protein isolate (SPI) were investigated under enzyme-specific hydrolysis conditions to comparatively assess the structural, functional, and instrumental taste differences among the resulting hydrolysates. Under the enzyme-specific hydrolysis conditions, among the enzymes tested, thermolysin induced substantial fragmentation of SPI, with products mainly distributed below 25 kDa and accompanied by marked conformational rearrangement. Thermolysin-treated SPI exhibited the highest total free amino acid content (14.805 mg/g), especially Tyr and Phe, together with the highest solubility (80.52 ± 4.40%), the highest emulsifying activity index (36.11 m²/g), and the strongest antioxidant capacities in 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay (DPPH), and hydroxyl radical scavenging assays. Electronic tongue analysis further showed that enzymatic hydrolysis generally enhanced umami and richness while reducing astringency relative to native SPI. Notably, SPI-Ther exhibited the most pronounced instrumental taste reconfiguration, characterized by increased umami (9.57) and richness (7.57), but also the highest bitterness (4.75) and aftertaste-B (3.46), indicating a distinct functionality–taste trade-off rather than simple debittering. In contrast, papain generated the highest umami response, whereas trypsin produced the mildest taste profile with the lowest bitterness. Overall, under the enzyme-specific hydrolysis conditions used in this study, thermolysin yielded the most pronounced improvement in the measured functional indices of SPI. However, these findings should be interpreted as a comparative, condition-specific assessment rather than a direct ranking of intrinsic protease specificity, and additional peptide characterization and sensory validation would be needed before taste-oriented applications can be recommended. Full article

Marine-derived bioactive peptides have attracted increasing attention as value-added functional ingredients. In this study, peptides (<3 kDa) were prepared from yellowfin tuna processing by-products and further fractionated by Sephadex G-25 gel filtration. The major fraction (TBP-MF) exhibited markedly improved compositional homogeneity compared with the unfractionated hydrolysate (TBP), providing a well-defined peptide system for subsequent characterization and biological evaluation. Physicochemical analyses demonstrated that TBP-MF possessed enhanced thermal stability and a more ordered secondary structure, characterized by pronounced β-sheet enrichment, as revealed by TGA/DSC, FTIR, and circular dichroism analyses. Morphological and colloidal characterization further showed that TBP-MF formed relatively uniform lamellar and fibrous assemblies with a narrower particle size distribution and reduced electrostatic stabilization, indicating a higher tendency toward ordered self-association. Peptidomic profiling combined with in silico analysis revealed that TBP-MF was enriched in short peptides with relatively higher PeptideRanker scores and a functional motif distribution containing relatively more neuro-related annotations, although angiotensin-converting enzyme (ACE)- and dipeptidyl peptidase IV (DPP-IV)-related motifs remained predominant in both groups. In differentiated PC12 cells, TBP-MF exhibited excellent cytocompatibility and induced a stable, concentration-dependent increase in the Cell Counting Kit-8 (CCK-8) readout (OD₄₅₀), indicating enhanced cellular metabolic activity and/or increased cell number. In addition, TBP-MF significantly increased intracellular levels of key neurochemical factors associated with sleep-related regulation, including tetrahydrobiopterin (BH4), serotonin (5-HT), and γ-aminobutyric acid (GABA). Overall, this study highlights yellowfin tuna by-products as a promising marine resource for bioactive peptides and suggests that fractionation-driven structural refinement is associated with neuro-related biological activity in differentiated PC12 cells. These findings support the potential application of marine by-product-derived peptides as functional ingredients in health-related fields. Full article

Chicken hemoglobin represents a source of bioactive peptides that could replace synthetic additives. This study evaluated the antibacterial and antifungal potential of chicken hemoglobin hydrolysates and the effect of their fractionation by EDUF. Hemoglobin was hydrolyzed with pepsin at pH 3 for 0.5 h and 6 h, followed by discoloration, and then fractionated by EDUF for 180 min at pH 7. Fractions were characterized using RP-UPLC-MS/MS, and antimicrobial activity was assessed. Antibacterial activity against Escherichia coli was observed only in EDUF fractions (P+180 and P−180), while crude hydrolysates showed no effect. However, MIC values of these EDUF fractions indicated weak inhibition. Antifungal activity was primarily detected in the final feed fractions against Mucor racemosus and Rhodotorula mucilaginosa (MIC: 0.04–20.00 mg/mL). Database matching of the fractions identified 22 sequences corresponding to peptides previously reported as bioactive, including ALARL, FDK, LARL, and VVYPW, which have been associated with antioxidant, ACE-inhibitory, antihypertensive, and enzyme-inhibitory properties. Nevertheless, EDUF proved to be an efficient, solvent-free, and low-energy approach for the recovery of peptide fractions from chicken hemoglobin, supporting the potential development of natural bioactive ingredients within a circular bioeconomy. Modifications of EDUF parameters, such as membrane configuration, pH, and voltage, could further enhance peptide selective recovery and the enrichment of functional fractions. Full article

Sweet potato (Ipomoea batatas (L.) Lam) is an important food and energy crop. Soil salinization is a major abiotic stress that limits agricultural productivity and severely reduces yield of crops. Protein hydrolysates, as a class of natural biostimulants, have gained increasing attention for their potential to improve crop yield, quality and stress tolerance. This study investigated the effects of peptides from swine blood (PSB) on high salinity stress tolerance in sweet potato. Application of PSB promoted the growth of both aerial and underground parts of sweet potato under normal and high-salinity conditions. Further analysis revealed that, under high salinity stress, exogenous PSB up-regulated the expression of genes associated with stress responses, increased the accumulation of organic osmotic adjustment compounds such as free amino acids, promoted K⁺ uptake to elevate the K⁺/Na⁺ ratio, and enhanced the activity of key antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) involved in the reactive oxygen species-scavenging system. These biochemical responses contributed to maintaining cellular osmotic balance and redox homeostasis, protecting the cell membrane from damage while preserving its structural integrity and normal physiological functions, and improving photosynthetic efficiency, thereby enhancing high salinity stress tolerance in sweet potato. Thus, PSB holds significant potential as an effective natural biostimulant for sweet potato cultivation in saline soils. Full article

Enzymatic hydrolysis is one of the effective methods used to obtain the bioactive peptides from marine resources. This study aimed to evaluate effect of the enzyme type (Food Pro PNL (FP), Corolase8000 (C8), and Corolase7089 (C7)) and biomass pretreatment level (whole starfish (SF), deproteinized (DPSF) as well as deproteinized and demineralized starfish (DPDMSF)) on the hydrolysate yield, degree of hydrolysis (DH), generated peptides’ molecular weight (MW), and in vitro radical scavenging and antiproliferative effects. Regardless of the enzyme used, deproteinization reduced the hydrolysate yield (<8% dw/ww) and DH (<5%), but also adding demineralization, in combination with C8, resulted in an equal yield (15%) and DH (>40%) to SF. However, the protein content of hydrolysates from DPSF and DPDMSF was higher than that prepared from SF. C8 was not effective in hydrolyzing SF but was the only effective enzyme in hydrolyzing DPDMSF. The peptides’ MW distribution strongly depended on the pretreatment and enzyme type, mostly ranging from 17 to 70 kDa. Glycine content was higher in hydrolysates from DPSF and DMDPSF, indicating their collagenous nature. Hydrolysates from DPSF, rich in collagenous peptides, showed medium MW but the highest radical scavenging activity. Only SF-FP hydrolysate, rich in non-collagenous peptides, showed antiproliferative activity against melanoma cancer cells. Overall, the findings demonstrate that upstream biomass pretreatment and enzyme selection directly govern the yield and bioactivity of starfish protein hydrolysates, providing a rational basis for designing starfish protein hydrolysates with targeted functional properties. Full article