Soybean Peroxidase Research Articles

Transcription factor GmAlfin09 regulates endoplasmic reticulum stress in soybean via peroxidase GmPRDX6.

Soybean (Glycine max [L.] Merr.) is a valuable oil crop but is also highly susceptible to environmental stress. Thus, developing approaches to enhance soybean stress resistance is vital to soybean yield improvement. In previous studies, transcription factor Alfin has been shown to serve as an epigenetic regulator of plant growth and development. However, no studies on Alfin have yet been reported in soybean. In this study, the endoplasmic reticulum (ER) stress- and reactive oxygen species (ROS)-related GmAlfin09 was identified. Screening of genes co-expressed with GmAlfin09 unexpectedly led to the identification of soybean peroxidase 6 (GmPRDX6). Further analyses revealed that both GmAlfin09 and GmPRDX6 were responsive to ER stress, with GmPRDX6 localizing to the ER under stress. Promoter binding experiments confirmed the ability of GmAlfin09 to bind to the GmPRDX6 promoter directly. When GmAlfin09 and GmPRDX6 were overexpressed in soybean, enhanced ER stress resistance and decreased ROS levels were observed. Together, these findings suggest that GmAlfin09 promotes the upregulation of GmPRDX6, and GmPRDX6 subsequently localizes to the ER, reduces ROS levels, promotes ER homeostasis, and ensures the normal growth of soybean even under ER stress. This study highlights a vital target gene for future molecular breeding of stress-resistant soybean lines.

Evaluation of Interactions of Added Soybean Peroxidase with Other Nutrients Present in Fish Feeds Using an In Vitro Digestive Simulation.

Peroxidase (PO) has been applied in different areas of industrial biotechnology, including the control of contaminants like aflatoxin B1 in fish feeds. However, its potential negative interactions with the macro and micro components of feeds have not been evaluated. The aim of this study was to evaluate the impact of PO's addition to a feed on compounds like fatty acids and polyphenols using an in vitro simulation of the digestive tract of the tilapia. The influence on fatty acids was determined by changes in the peroxide index, with the feed including PO presenting values four times higher than those of the control feed. On the other hand, the in vitro digestive simulation also evidenced an effect of PO on the bioaccessibility of polyphenols significantly influenced by the total digestion time and temperature. The bioaccessibility of polyphenol ranged from 2.09 to 16.23 μmol of the total Trolox equivalent antioxidant capacity for the combinations evaluated in the study. The greatest bioaccessibility was observed at the central point under the following conditions of digestive hydrolysis: pH of 7, 30 °C, 4.5 h of digestive hydrolysis and an absence of PO.

Antibacterial properties of functionalized cellulose extracted from deproteinized soybean hulls

Soybean hulls (SBHs) are one of the main by-products of soybean crushing, usually destined for animal feeding or to become a putrescible waste. In this work, we upgraded the SBHs to materials with antimicrobial properties. After the extraction of soybean peroxidase from SBHs, an enzyme applicable in different technological sectors and naturally present in soybean hulls, the exhausted biomass was subjected to an acid–base treatment to isolate cellulose. The obtained material was, in turn, functionalized with 3-aminopropyl triethoxysilane (APTES) to achieve new hybrids with antimicrobial properties. The synthetic procedure was optimized by varying the solvent type (ethanol or toluene) and APTES amount. Overall, the amino-functionalization process was effective and the activity was outstanding against both gram-positive and gram-negative bacteria, reaching complete disinfection practically in all cases. The samples were studied by means of several characterization techniques, demonstrating that the solvent and cellulose types had a significant influence on the physical–chemical features, together with the eco-sustainability of the process. In particular, the use of greener ethanol and waste cellulose (with respect to a commercial one) resulted in a higher APTES immobilization efficiency and superior thermal stability of the final materials. Interestingly, the presence of various unremoved compounds from the lignocellulosic SBH matrix, although in small quantities, emerged as a crucial factor, also in terms of antibacterial activity, hypothesizing a role of residual phytochemicals.

Evaluation of soybean peroxidase - Copper phosphate mediated organic-inorganic hybrid for hydrogen peroxide biosensor application

An electrochemical biosensor for H2O2 detection was developed by using soybean peroxidase-copper phosphate mediated organic inorganic hybrid (OIH). The characterization of OIH was carried out by FESEM and FTIR. FESEM analysis showed a flower-like porous morphology of the OIH and FTIR confirmed the presence of soybean peroxidase and copper phosphate in the OIH. For sensor development, the paste of OIH was formulated in the presence of phosphate buffered saline (PBS) and was screen printed on indium tin oxide (ITO) coated glass substrate. Cyclic voltammetry analysis showed that the developed biosensor could detect H2O2 in the linear range of 20–100 ​μM with R2 value of 0.963. The limit of detection (LOD) and sensitivity values calculated for H2O2 are 0.19 ​μM and 27.44 μA/(μM.cm2) respectively. Along with cyclic voltammetry experiments, electrochemical impedance spectroscopy (EIS) analysis was also carried out to study the sensing mechanism. The developed biosensor showed better selectivity towards H2O2 when tested against d-glucose, l-tyrosine, l-lysine, and l-ascorbic acid.

Soybean peroxidase immobilised on cellulose-alginate hydrogels for removal of recalcitrant organic pollutants in water

Biodegradable, waste-derived hydrogels containing immobilised peroxidase were successfully used for enzymatic removal of organic pollutants in water. Hydrogels are reusable and provide detoxification of the contaminants solution.

Application of Fe(III)–EDDS complexes and soybean peroxidase in photo-Fenton processes for organic pollutant removal: insights into possible synergistic effects

Photo-Fenton processes activated by biodegradable Fe(III)–EDDS complexes have attracted huge attention from the scientific community, but the operative mechanism of the photo-activation of H2O2 in the presence of Fe(III)–EDDS has not been fully clarified yet. The application of the Fe(III)–EDDS complex in Fenton and photo-Fenton (mainly under UV-B light) processes, using 4-chlorophenol (4-CP) as a model pollutant was explored to give insights into the operative mechanism. Furthermore, the potential synergistic contribution of soybean peroxidase (SBP) was investigated, since it has been reported that upon irradiation of Fe(III)–EDDS the production of H2O2 can occur. SBP did not boost the 4-CP degradation, suggesting that the possibly produced H2O2 reacts immediately with the Fe(II) ion with a quick kinetics that does not allow the diffusion of H2O2 into the bulk of the solution (i.e., outside the solvent cage of the complex). So, a concerted mechanism in which the photochemically produced H2O2 and Fe(II) react inside the hydration sphere of the Fe(III)–EDDS complex is proposed.Graphical abstract

Self-assembly of soybean peroxidase nanohybrid for activity enhancement and dye decolorization: experimental and computational studies

The soybean peroxidase (SBP) mediated nanohybrid [SBP-Cu3(PO4)2·3H2O] synthesis was carried out in the present study. The scanning electron microscopy (SEM) analysis showed a characteristic flower-like hierarchical structure of the SBP-nanohybrid. The mechanism of SBP-nanohybrid formation was elucidated using computational approaches. The predicted Cu2+ binding sites followed by molecular docking studies showed the two lowest energy (−4.4 kcal/mol and −3.56 kcal/mol) Cu2+ binding sites. These two binding sites are located at the opposite position and might be involved in the formation of SBP-nanohybrid assemblies. Further, these sites are different than the catalytic active site pocket of SBP, and may facilitate more substrate catalysis. Obtained computational results were confirmed by in-vitro guaiacol oxidations studies using SBP-nanohybrid. The effect of various parameters on SBP-nanohybrid activity was studied. The pH 7.2 was found optimum for SBP-nanohybrid activity. The enzyme activity increased with an increase in temperature up to 50 °C temperature and then decreased with an increase in temperature. Around ∼138% enhanced activity was recorded using SBP-nanohybrid compared to crude SBP. Also, the SBP-nanohybrid showed around 95% decolorization of methylene blue (MB) in 1 h and the MB degradation was confirmed by high-pressure liquid chromatography analysis (HPLC). Communicated by Ramaswamy H. Sarma

Modeling and simulation of the enzymatic degradation of 2,4,6-trichlorophenol using soybean peroxidase

The enzymatic degradation of organic pollutants is a promising and ecological method for the remediation of industrial effluents. 2,4,6-Trichlorophenol is a major pollutant in many residual waters, and its consumption has been linked to lymphomas, leukemia, and liver cancer. The goal of the present work is to comprehend the enzymatic degradation of 2,4,6-trichlorophenol using soybean peroxidase. Different assumptions for the kinetic model were evaluated, and the simulations were compared to experimental data, which was obtained in a microreactor. The literature pointed out that the bi-bi ping-pong model represents well the kinetics of soybean peroxidase degradation. Since it is a complex model, some reactions can be considered or not. Six different possibilities for the model were considered, regarding different combinations of the generated enzyme forms that depend on the hypotheses for simplifying the model. The adjustment of the models was compared based on different metrics, such as the value of the objective function, coefficient of determination and root-mean-square error. The process modeling was obtained by the mass balance of all the reaction components, and all the simulations were performed in MATLAB R2015a. Reaction parameters were estimated based on the weighted least squares between the experimental data set and the values predicted by the model. The results showed that the data were better adjusted by the model that considers all the enzyme forms, including enzyme inactivation. Therefore, a better comprehension of the reaction mechanism was achieved, which allows a more precise reactor project and process simulation.

Immobilized Soybean Peroxidase Hybrid Biocatalysts for Efficient Degradation of Various Emerging Pollutants.

In the present study, soybean peroxidase (SBP) was covalently immobilized onto two functionalized photocatalytic supports (TiO2 and ZnO) to create novel hybrid biocatalysts (TiO2-SBP and ZnO-SBP). Immobilization caused a slight shift in the pH optima of SBP activity (pH 5.0 to 4.0), whereas the free and TiO2-immobilized SBP showed similar thermal stability profiles. The newly developed hybrid biocatalysts were used for the degradation of 21 emerging pollutants in the presence and absence of 1-hydroxy benzotriazole (HOBT) as a redox mediator. Notably, all the tested pollutants were not equally degraded by the SBP treatment and some of the tested pollutants were either partially degraded or appeared to be recalcitrant to enzymatic degradation. The presence of HOBT enhanced the degradation of the pollutants, while it also inhibited the degradation of some contaminants. Interestingly, TiO2 and ZnO-immobilized SBP displayed better degradation efficiency of a few emerging pollutants than the free enzyme. Furthermore, a combined enzyme-chemical oxidation remediation strategy was employed to degrade two recalcitrant pollutants, which suggest a novel application of these novel hybrid peroxidase-photocatalysts. Lastly, the reusability profile indicated that the TiO2-SBP hybrid biocatalyst retained up to 95% degradation efficiency of a model pollutant (2-mercaptobenzothiazole) after four consecutive degradation cycles.

Plant-derived soybean peroxidase stimulates osteoblast collagen biosynthesis, matrix mineralization, and accelerates bone regeneration in a sheep model

Bone defects arising from fractures or disease represent a significant problem for surgeons to manage and are a substantial economic burden on the healthcare economy. Recent advances in the development of biomaterial substitutes provides an attractive alternative to the current “gold standard” autologous bone grafting. Despite on-going research, we are yet to identify cost effective biocompatible, osteo-inductive factors that stimulate controlled, accelerated bone regeneration.We have recently reported that enzymes with peroxidase activity possess previously unrecognised roles in extracellular matrix biosynthesis, angiogenesis and osteoclastogenesis, which are essential processes in bone remodelling and repair. Here, we report for the first time, that plant-derived soybean peroxidase (SBP) possesses pro-osteogenic ability by promoting collagen I biosynthesis and matrix mineralization of human osteoblasts in vitro. Mechanistically, SBP regulates osteogenic genes responsible for inflammation, extracellular matrix remodelling and ossification, which are necessary for normal bone healing. Furthermore, SBP was shown to have osteo-inductive properties, that when combined with commercially available biphasic calcium phosphate (BCP) granules can accelerate bone repair in a critical size long bone defect ovine model. Micro-CT analysis showed that SBP when combined with commercially available biphasic calcium phosphate (BCP) granules significantly increased bone formation within the defects as early as 4 weeks compared to BCP alone. Histomorphometric assessment demonstrated accelerated bone formation prominent at the defect margins and surrounding individual BCP granules, with evidence of intramembranous ossification. These results highlight the capacity of SBP to be an effective regulator of osteoblastic function and may be beneficial as a new and cost effective osteo-inductive agent to accelerate repair of large bone defects.

Elimination of selected heterocyclic aromatic emerging contaminants from water using soybean peroxidase

Widespread occurrence of various heterocyclic aromatic compounds is reported in concentrations from 1 to 20 μg/L in surface and groundwater as well as influents and effluents of wastewater treatment plants around the world. These so-called emerging contaminants and their metabolites can cause adverse effects on the environment and humans, even at very low concentration, hence raised environmental concerns. In this study, feasibility of soybean peroxidase-catalyzed removal of three selected heterocyclic aromatics from water was investigated, including sensitivity to the most important operational conditions, pH (range 3.6-9.0), H2O2 concentration (range 0.10-1.50 mM), and enzyme activity (range 0.001-5.0 U/mL). 3-Hydroxycoumarin and 2-aminobenzoxaozle were found to be substrates for the enzyme, having ≥95% and 45% removal efficiency with most effective pHs of 7.0 and 6.0, respectively. Time course study was also conducted to determine the initial first-order rate constants and half-lives; half-lives normalized for enzyme activity (0.0257 and 452 min for the respective substrates) are compared with those of 21 other compounds reactive with soybean peroxidase. High-resolution mass spectrometry was employed to characterize the plausible oligomerization products of enzymatic treatment, which revealed formation of dimers and trimers of the two substrates.

Immobilized bi-enzymatic system for the determination of biogenic amines in solution

Biogenic amines are a group of important organic bases involved in the metabolism of living organisms and present in biological fluids, food or beverages. Their identification and quantification represent relevant issues in the field of bio-analytical and food chemistry. Beyond the traditional detection techniques, other methods have been recently exploited, as enzymatic-based systems. Herein, diamine-oxidase (DAO) and soybean peroxidase (SBP) were immobilized onto silica spherical monoliths (prepared from biowaste-derived substances) to realize a practical and fast enzymatic system, able to quantify biogenic amines in solution. The mechanism consisted in the oxidation of amines by DAO with the formation of H2O2, which in turn activated the SBP reaction producing an indamine dye. The amount of amine was indirectly determined by the spectroscopic measurement of the final product. Preliminary kinetic tests on DAO/SBP catalytic system using histamine as DAO substrate showed the maximum activity at pH 8. Furthermore, the stability of the functionalized monoliths over several reaction cycles and their catalytic action towards cadaverine, tyramine, tyrosine and histamine were studied. The results showed that the immobilized DAO/SBP system was effective in the determination of different substrates for many cycles, reaching a detection limit comparable to chromatographic methods.

Detoxification of Sunset yellow and Brilliant blue dyes using Soybean peroxidases

This present study aims to evaluate the peroxidase activity in soybean extract which was obtained through the seeds of the soybean. This enzymatic extract (Soybean Peroxidase-SBP) was then compared with commercially available pure enzyme i.e., horseradish peroxidase (HRP). The effect of the enzyme concentration, substrate concentration, pH temperature were studied to interpret the factors affectingthe rate of the reaction. Therefore, after the studies were carried out, it was detected that the increase in the concentration of the substrate as well as enzyme resulted in the gradual increase of the activity. The rate of the reaction thus became constant when all the enzymes got saturated after a certain range. The optimum pH and temperature of 7 and 40 ​°C was maintained for the decolorization of the synthetic dyes viz., Sunset yellow and Coomassie Brilliant blue dye R-250. The removal of Sunset yellow dye and CBB was around 45 % and 11 %, respectively and results were compared with the degradation with HRP in similar conditions. The effective degradation of Sunset yellow over CBB may be because of the difference in the molecular weight. Furthermore, optimization of reaction mixture and reaction conditions is in progress. The results obtained in this work suggest that peroxidases can be used in a supplementary step to the conventional processes for specific dye removal.

Decoloration Reactivity and Kinetics of Mixed Azo Dye Solution Using Soybean Peroxidase Immobilized PET Fabric

Decoloration Reactivity and Kinetics of Mixed Azo Dye Solution Using Soybean Peroxidase Immobilized PET Fabric

Biocatalytic oligomerization of azoles; experimental and computational studies

Soybean peroxidase effectively transformed selected amino- and hydroxyl-azoles by radical coupling to dimers and trimers, showing feasibility for wastewater treatment.

Soybean peroxidase treatment of ultra-high kappa softwood pulp to enhance yield and physical properties

The working hypothesis serving as basis for this study is that pulping to a higher kappa number will produce a higher yield pulp, and then treating that pulp with a surface reactive lignin peroxidase to ablate surface lignin will increase specific bonding area. In the present case, the working hypothesis was modified so that soybean peroxidase (SBP) works like lignin peroxidase to modify surface lignin on high-kappa, high-yield softwood pulps to facilitate enhanced fiber-to-fiber bonding such that the resulting paper strength is similar to the lower kappa soft-wood pulp generally used to make linerboard. Soybean peroxidase is actually a plant peroxidase that exhibits lignin peroxidase-like activity. It is not a lignin peroxidase derived from white rot fungus. The current work did show a significant improvement in pulp yield (62.2% vs. 55.2% yield for a 103-kappa control linerboard grade sheet), while treatment with SBP showed that tensile, burst, and STFI properties of the pulp were improved, although more convincing data needs to be obtained.

Soybean peroxidase‐catalyzed degradation of a sulfonated dye and its azo‐cleavage product

AbstractBACKGROUNDThe presence of azo dyes in wastewater from the textile industry is a major environmental concern. The dyes not only make water aesthetically unacceptable, but also have severe toxicological concerns. Research into treatment processes for removal of dyes has focused primarily on decolourization and little attention has been focused on analysis of the degradation products, that could plausibly be more toxic than the parent compound. This study focusses on soybean peroxidase (SBP)‐catalyzed treatment of two azo dyes, Methyl Orange (MO) and CI Direct Yellow 12 (DY12) in water, chosen because they lack phenolic and primary anilino functional groups, which are usually expected to form free radicals under peroxidase catalysis.RESULTSDY12 was found not to be a substrate of SBP, but optimized reaction conditions for 0.50 mmol L–1 MO and 1.0 mmol L–1 p‐anisidine (structurally analogous to 4‐ethoxyaniline, a possible azo‐cleavage product of DY12) achieved ≥95% conversion at exceptionally low minimum effective SBP activities (0.0070 and 0.0018 U mL–1) at pH optima of 4.0 and 5.5 and [hydrogen peroxide]/[substrate] of 2 and 1, respectively.CONCLUSIONSMass spectrometric (MS) analysis for the substrates revealed formation of dimers and trimers for p‐anisidine. For MO, high‐performance liquid chromatography, UV‐visible spectrophotometry and MS provided evidence of azo‐bond cleavage, hetero‐coupling of the dye with the cleavage product and also self‐coupling of the dye through tertiary amine activation. © 2020 Society of Chemical Industry (SCI)

A Way to Close the Loop: Physicochemical and Adsorbing Properties of Soybean Hulls Recovered After Soybean Peroxidase Extraction.

Soybean hulls are one of the by-products of soybean crushing and find application mainly in the animal feed sector. Nevertheless, soybean hulls have been already exploited as source of peroxidase (soybean peroxidase, SBP), an enzyme adopted in a wide range of applications such as bioremediation and wastewater treatment, biocatalysis, diagnostic tests, therapeutics and biosensors. In this work, the soybean hulls after the SBP extraction, destined to become a putrescible waste, were recovered and employed as adsorbents for water remediation due to their cellulose-based composition. They were studied from a physicochemical point of view using different characterization techniques and applied for the adsorption of five inorganic ions [Fe(III), Al(III), Cr(III), Ni(II), and Mn(II)] in different aqueous matrixes. The behavior of the exhausted soybean hulls was compared to pristine hulls, demonstrating better performances as pollutant adsorbents despite significant changes in their features, especially in terms of surface morphology, charge and composition. Overall, this work evidences that these kinds of double-recovered scraps are an effective and sustainable alternative for metal contaminants removal from water.

Enzymatic Degradation of 2,4,6-Trichlorophenol in a Microreactor using Soybean Peroxidase

Soybean peroxidase is an enzyme extracted from soybean seed hulls. In the presence of hydrogen peroxide, the enzyme has the potential to catalyze the biodegradation of toxic substances like chlorophenols. For this reason, its use in wastewater treatment processes is environmentally friendly since the enzyme can be obtained from a renewable and abundant raw material. In this work, enzymatic biodegradation of 2,4,6-trichlorophenol performed by soybean peroxidase in a microreactor was studied experimentally and theoretically. The experimental data set was obtained with a volume of 250 μL by using different soybean peroxidase concentrations and different reaction times. The fluid dynamics of the microreactor was modeled as well, using ANSYS CFX. The simulations exhibited secondary flows, which enhanced mixing. Although the laminar flow was developed, it can be assumed to be a well-mixed medium. The kinetic data were evaluated through a mechanistic model, the modified bi-bi ping-pong model, which is adequate to represent the enzymatic degradation using peroxidases. The model was composed of an initial value problem for ordinary differential equations that were solved using MATLAB. Some kinetic constants were estimated using the least square function. The results of the model fit well the experimental data.

Soybean Peroxidase Catalyzed Decoloration of Acid Azo Dyes.

Background.Some industrial manufacturing processes generate and release dyes as water pollutants, many of which are toxic and hazardous materials. There is a need for milder, greener methods for dye treatment.Objectives.The objective of the present study was to investigate and optimize azo dye decoloration by a crude soybean peroxidase (SBP), based on two dyes that have widespread industrial use, but that differ greatly in structural complexity, Acid Black 2 and Acid Orange 7, and to investigate the effects of specific parameters on the removal process.Methods.Batch reactors were used to remove 95% of the dyes' color and to produce substantial precipitates.Results.The optimum pH for enzymatic decoloration of Acid Black 2 was in the acidic region, pH 4.4, and that of Acid Orange 7 occurred under neutral conditions, pH 6.9. The minimum enzyme activity needed for sufficient removal was 1.2 U/mL for both dyes at 0.5 mM. The minimum molar hydrogen peroxide/substrate ratio was 3 for Acid Orange 7 and 2.5 for Acid Black 2 to achieve approximately 95% removal. First-order fitting of progress curve data collected under the respective optimum conditions gave half-lives of 23.9 and 28.9 minutes for Acid Orange 7 and Acid Black 2, respectively.Conclusions.The feasibility of SBP-catalyzed treatment of industrial dyes Acid Black 2 and/or Acid Orange 7, or dyes that resemble them, as they might occur in industrial effluents, was successfully demonstrated.Competing Interests.The authors declare no competing financial interests