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Highlights: Two Aspergillus isolates from bitumen grow well on extra-heavy crude oil. Extracellular enzymes of both fungi efficiently degrade extra-heavy oil fractions. Hydrocarbon redistribution co-occurs with biogas and organic acid formation. Oil properties are enzymatically improved by viscosity reduction and demetallization. Heavy crude oil (HCO) and extra-heavy crude oil (EHCO) with high viscosity and density pose enormous challenges to the exploitation of oil reserves. While bacteria are increasingly used in biocatalytic upgrading of HCO and EHCO, less attention has been paid to the potential of fungi. The aim of this study was to ascertain the role of fungal extracellular enzymes from Aspergillus spp. In the biodegradation of EHCO and their application potential for enhanced oil recovery. A. terreus HJ2 and A. nidulans HJ4 with the ability to biodegrade HCO were previously isolated from bitumen enrichment cultures. Both strains grew well on EHCO agar plates supplemented with a small amount of soluble starch (0.2%) and yeast extract (0.3%). Extracellular enzymes from each strain separately, as well as mixtures of the enzymes, exhibited EHCO degradation activity, leading to redistribution of hydrocarbons with substantial formation of biogases and organic acids in a 7-day period. Enzymatic degradation resulted in decreased contents of resins and asphaltenes, accompanied by increased contents of saturates and aromatics. Gas chromatography–mass spectrometry revealed distinct redistribution patterns of n-alkane in the biotreated oil. Enzymatic degradation additionally caused considerable reduction in oil viscosity (by 12.7%) and heavy metal concentrations (Ni, by 44.1%; Fe, by 54.0%; V, by 31.6%). The results provide empirical evidence for the application potential of fungal extracellular enzymes from Aspergillus spp. in EHCO recovery and biocatalytic upgrading of EHCO. [ABSTRACT FROM AUTHOR]

A variety of important agricultural crops host fungi from the Aspergillus genus can produce cancerogenic secondary metabolites such as aflatoxins. Consequently, novel strategies for detoxification and their removal from food and feed chains are required. Here, detoxification of Aflatoxin B1 (AFB1) by the Bacillus subtilis multi-copper oxidase CotA (BsCotA) was investigated. This laccase was recombinantly produced in E. coli while codon optimization led to duplication of the amount of active protein obtained. CuCl2 was added to the cultivation medium leading to a 25-fold increase of Vmax corresponding to improved incorporation of Cu2+ into the enzyme protein which is essential for the catalytic reaction. To avoid potential cytotoxicity of Cu2+, cultivation was performed at microaerobic conditions indeed leading to 100x more functional protein when compared to standard aerobic conditions. This was indicated by an increase of Vmax from 0.30 ± 0.02 to 33.56 ± 2.02 U/mg. Degradation kinetics of AFB1 using HPLC with fluorescence detection (HPLC-FLD) analysis indicated a theoretical substrate saturation above solubility in water. At a relatively high concentration of 500 μg/L, AFB1 was decomposed at 10.75 μg/Lh (0.17 nmol*min−1*mg−1) at a dosage of 0.2 μM BsCotA. AFQ1 and epi-AFQ1 were identified as the initial oxidation products according to mass spectrometry (i.e., HPLC-MS, HPLC-QTOF). None of these molecules were substrates for laccase but both decomposed in buffer. However, decomposition does not seem to be due to hydration of the vinyl ether in the terminal furan ring. Genotoxicity of the formed AFB1 was assessed in several dilutions based on the de-repression of the bacterial SOS response to DNA damage indicating about 80-times reduction in toxicity when compared to AFQ1. The results of this study indicate that BsCotA has high potential for the biological detoxification of aflatoxin B1. [ABSTRACT FROM AUTHOR]

Although Alzheimer's disease (AD) is traditionally viewed as a central nervous system disorder driven by the cerebral accumulation of toxic beta-amyloid (Aβ) peptide, new interpretations of the amyloid cascade hypothesis have led to the recognition of the dynamic equilibrium in which Aβ resides and the importance of peripheral Aβ production and degradation in maintaining healthy Aβ levels. Our review sheds light on the critical role of peripheral organs, particularly the liver, in the metabolism and clearance of circulating Aβ. We explore the mechanisms of Aβ transport across the blood–brain barrier (BBB) via transport proteins such as LRP1 and P-glycoprotein. We also examine how peripheral clearance mechanisms, including enzymatic degradation and phagocytic activity, impact Aβ homeostasis. Our review also discusses potential therapeutic strategies targeting peripheral Aβ clearance pathways. By enhancing these pathways, we propose a novel approach to reducing cerebral Aβ burden, potentially slowing AD progression. [ABSTRACT FROM AUTHOR]

Polybutylene succinate, polybutylene adipate, polybutylene suberate and their copolyesters were synthesized. The physical properties and biodegradability of these polyesters were controlled by adjusting the composition of carboxyl monomers. Compared with the homopolyesters, the addition of comonomer during polymerization resulted in the formation of copolyesters with lower melting temperatures and crystallinity. Among them, poly(butylene succinate-co-adipate) (PBSA) had the lowest crystallinity, and poly(butylene adipate-co-suberate) (PBASub) had the lowest melting point. The elongation at break and tensile strength of PBSA was 766.2% and 21.5 MPa, respectively. Enzymatic degradation by Fusarium solani cutinase (FsC) showed that both the crystalline and amorphous regions of the polyester were simultaneously degraded by FsC, and the crystal structure of the polyester was not disrupted. FsC preferentially got attached to the surface of polyesters, subsequently attacked the center of the films, and the water penetrated the amorphous region, leading to enhanced enzymatic hydrolysis. The biodegradability of copolyester was higher than that of homopolyesters. PBSA and poly(butylene succinate-co-suberate) (PBSSub) were completely degraded in about 10 h, and can be used in agricultural, automotive, electronics, biomedical materials, packaging, etc.

Drug addiction is a pervasive problem worldwide. It not only affects the abuser's life, but also poses a serious threat to public health. Accordingly, there is a strong demand for the development of novel and effective therapies for drug addiction. Considering that small-molecule drugs have only had limited success, there is great interest in developing alternative strategies that extend the reach of small-molecule-based therapies. The antibody-based trapping approach and the enzyme catalytic strategy have been considered as promising ways to reduce the euphoria of drug users by altering drug pharmacokinetics and decreasing drug concentrations in the central nervous system. However, these biological macromolecules are generally unstable and their in vivo half-lives are short. With the rapid development of gene editing technologies, it is possible to perform ex vivo gene therapy for the long-term and stable delivery of enzymes and other effector proteins, which could free abusers from frequent injections of therapeutics. By constructing programmed gene switches that regulate spatiotemporal gene expression in response to illicit drugs, this perspective proposed the concept of preventing drug addiction by the drug itself. This strategy enables the controlled release of therapeutic proteins in vivo and is expected to improve patient safety and compliance. This will open up new opportunities for next-generation medicine and hold great promise for expanding our ability to treat drug addiction.

The emerging threat of antibiotic resistance and the formation of resilient biofilms pose a challenge to contemporary healthcare systems. This review dives into the interplay between antibiotic resistance mechanisms and biofilm production. Many pathogenic bacteria have an inherent ability of adhering tightly to a surface forming a complex matrix of extracellular polymeric substances (EPS) surrounding their cells. This is called a biofilm which allows pathogenic bacteria to survive in unsuitable environment. The adaptive nature of biofilms provides a protective shield against conventional antimicrobial agents, promoting chronic infections and complicating medical interventions. This phenomenon further adds to the ever-increasing problem of antibiotic resistance. Thus, there is an immediate necessity in developing novel strategies to deal with bacterial biofilms. In terms of human health, biofilms can be formed on mucosal surfaces and on surfaces of medical equipment. They are also a major reason for causing ‘biofouling’. Different approaches have been undertaken to counteract the menace of biofilms encompassing physical, chemical as well as biological methods. However, recent studies have shown that natural bioactive compounds found in fungal extracts, which has already been gaining attention due to their various properties like immunomodulatory activity, anti-tumor activity, antimicrobial activity etc., have the ability to prevent the formation as well as viability of biofilms through numerous mechanisms. This article thus explores the nuances of biofilm formation and its effects, and further delves deep into the convincing potential of the different components in fungal extracts against bacterial biofilms.

Objective: The goal of this systematic review was to identify the mechanisms associated with the enzymatic degradation of collagen and gelatin biomaterials and the possible associated flaws. Methods: Four databases (PubMed, B-On, Cochrane Library, and ResearchGate) were used for the bibliographic search of articles. The research question was formulated using the PCC method, (P): collagen or gelatin sponges, hydrogels, and scaffolds; concept (C): enzymatic degradation of collagen or gelatin sponges, hydrogels, and scaffolds; and context (C): effect of enzymatic action on degradation time of collagen or gelatin sponges, hydrogels, and scaffolds. The search was contextualized according to PRISMA recommendations. The identification and exclusion of evidence followed the PRISMA criteria, with specific inclusion and exclusion factors being stipulated for the selection of articles. The risk of bias assessment was performed using the QUIN Scale. Results: The initial search was composed of 13,830 articles after removing duplicates; 56 articles followed for the full-text reading; 45 were excluded; then, 11 articles were obtained, constituting the results of this systematic review. All studies evaluated the materials using gravimetric analysis, and collagenases were the proteases used for the degradation solution. The materials tested were as follows: human-like collagen (HLC) hydrogel with microbial transglutaminase (MTGase), gelatin sponges subjected to different types of crosslinking, and collagen scaffolds with different types of crosslinking. The period of analysis varied between 0.25 h and 35 days. It was possible to highlight the lack of uniformity in the protocols used, which varied largely, thus influencing the degradation times. The risk of bias was low in nine studies and medium in two studies. Conclusions: This systematic review identified a gap in the literature, highlighting the absence of in vitro studies using human saliva and a collagenase concentration close to the physiological levels to simulate oral dynamics. However, based on existing literature, the mechanisms associated with collagen enzymatic degradation in collagen and gelatin biomaterials were comprehensively understood, answering the first research question postulated. In response to the second research question, the main shortcomings identified in the laboratory evaluation of mechanisms associated with collagen enzymatic degradation in collagen and gelatin biomaterials included the lack of standardization in degradation test protocols; this limited inter-study comparisons, which increased heterogeneity. Additionally, variations in collagenase concentrations and types influenced collagen degradation rates, and inappropriate evaluation intervals hindered the identification of total degradation time.

A series of partially bio-based and biodegradable poly(propylene terephthalate-co-adipate) (PPTA) random copolymers with different components were prepared by the melt polycondensation of petro-based adipic acid and terephthalic acid with bio-based 1,3-propanediol. The microstructure, crystallization behavior, thermal properties, and enzymatic degradation properties were further investigated. The thermal decomposition kinetics was deeply analyzed using Friedman's method, with the thermal degradation activation energy ranging from 297.8 to 302.1 kJ/mol. The crystallinity and wettability of the copolymers decreased with the increase in the content of the third unit, but they were lower than those of the homopolymer. The thermal degradation activation energy E, carbon residue, and reaction level n all showed a decreasing trend. Meanwhile, the initial thermal decomposition temperature (Td) was higher than 350 °C, which can meet the requirements for processing and use. The PPTA copolymer material still showed excellent thermal stability. Adding PA units could regulate the crystallinity, wettability, and degradation rate of PPTA copolymers. The composition of PPTA copolymers in different degradation cycles was characterized by 1H NMR analysis. Further, the copolymers' surface morphology during the process of enzymatic degradation also was observed by scanning electron microscopy (SEM). The copolymers' enzymatic degradation accorded with the surface degradation mechanism. The copolymers showed significant degradation behavior within 30 days, and the rate increased with increasing PA content when the PA content exceeded 45.36%. [ABSTRACT FROM AUTHOR]

Objective: The goal of this systematic review was to identify the mechanisms associated with the enzymatic degradation of collagen and gelatin biomaterials and the possible associated flaws. Methods: Four databases (PubMed, B-On, Cochrane Library, and ResearchGate) were used for the bibliographic search of articles. The research question was formulated using the PCC method, (P): collagen or gelatin sponges, hydrogels, and scaffolds; concept (C): enzymatic degradation of collagen or gelatin sponges, hydrogels, and scaffolds; and context (C): effect of enzymatic action on degradation time of collagen or gelatin sponges, hydrogels, and scaffolds. The search was contextualized according to PRISMA recommendations. The identification and exclusion of evidence followed the PRISMA criteria, with specific inclusion and exclusion factors being stipulated for the selection of articles. The risk of bias assessment was performed using the QUIN Scale. Results: The initial search was composed of 13,830 articles after removing duplicates; 56 articles followed for the full-text reading; 45 were excluded; then, 11 articles were obtained, constituting the results of this systematic review. All studies evaluated the materials using gravimetric analysis, and collagenases were the proteases used for the degradation solution. The materials tested were as follows: human-like collagen (HLC) hydrogel with microbial transglutaminase (MTGase), gelatin sponges subjected to different types of crosslinking, and collagen scaffolds with different types of crosslinking. The period of analysis varied between 0.25 h and 35 days. It was possible to highlight the lack of uniformity in the protocols used, which varied largely, thus influencing the degradation times. The risk of bias was low in nine studies and medium in two studies. Conclusions: This systematic review identified a gap in the literature, highlighting the absence of in vitro studies using human saliva and a collagenase concentration close to the physiological levels to simulate oral dynamics. However, based on existing literature, the mechanisms associated with collagen enzymatic degradation in collagen and gelatin biomaterials were comprehensively understood, answering the first research question postulated. In response to the second research question, the main shortcomings identified in the laboratory evaluation of mechanisms associated with collagen enzymatic degradation in collagen and gelatin biomaterials included the lack of standardization in degradation test protocols; this limited inter-study comparisons, which increased heterogeneity. Additionally, variations in collagenase concentrations and types influenced collagen degradation rates, and inappropriate evaluation intervals hindered the identification of total degradation time. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) are widespread, persistent, and toxic environmental pollutants. Many anthropogenic and some natural factors contribute to the spread and accumulation of PAHs in aquatic and soil systems. The effective and environmentally friendly remediation of these chemical compounds is an important and challenging problem that has kept scientists busy over the last few decades. This review briefly summarizes data on the main sources of PAHs, their toxicity to living organisms, and physical and chemical approaches to the remediation of PAHs. The basic idea behind existing approaches to the bioremediation of PAHs is outlined with an emphasis on a detailed description of the use of bacterial strains as individual isolates, consortia, or cell-free enzymatic agents. [ABSTRACT FROM AUTHOR]

In the present study, a new degraded konjac glucomannan (DKGM) was prepared using a crude enzyme from abalone (Haliotis discus hannai) viscera, and its physicochemical properties were investigated. After enzymatic hydrolysis, the viscosity of KGM obviously decreased from 15,500 mPa·s to 398 mPa·s. The rheological properties analysis of KGM and DKGMs revealed that they were pseudoplastic fluids, and pseudoplasticity, viscoelasticity, melting temperature, and gelling temperature significantly decreased after enzymatic hydrolysis, especially for KGM-180 and KGM-240. In addition, the molecular weight of KGM decreased from 1.80 × 106 Da, to 0.45 × 106 Da and the polydispersity index increased from 1.17 to 1.83 after 240 min of degradation time. Compared with natural KGM, the smaller particle size distribution of DKGM further suggests enzyme hydrolysis reduces the aggregation of molecular chains with low molecular weight. FT-IR and FESEM analyses showed that the fragmented KMG chain did not affect the structural characteristics of molecular monomers; however, the dense three-dimensional network microstructure formed by intermolecular interaction changed to fragment microstructure after enzyme hydrolysis. These results revealed that the viscosity and rheological properties of KGM could be controlled and effectively changed using crude enzymes from abalone viscera. This work provides theoretical guidance for the promising application of DKGM in the food industry. [ABSTRACT FROM AUTHOR]

A variety of important agricultural crops host fungi from the Aspergillus genus can produce cancerogenic secondary metabolites such as aflatoxins. Consequently, novel strategies for detoxification and their removal from food and feed chains are required. Here, detoxification of Aflatoxin B1 (AFB1) by the Bacillus subtilis multi-copper oxidase CotA (BsCotA) was investigated. This laccase was recombinantly produced in E. coli while codon optimization led to duplication of the amount of active protein obtained. CuCl2 was added to the cultivation medium leading to a 25-fold increase of Vmax corresponding to improved incorporation of Cu2+ into the enzyme protein which is essential for the catalytic reaction. To avoid potential cytotoxicity of Cu2+, cultivation was performed at microaerobic conditions indeed leading to 100x more functional protein when compared to standard aerobic conditions. This was indicated by an increase of Vmax from 0.30 ± 0.02 to 33.56 ± 2.02 U/mg. Degradation kinetics of AFB1 using HPLC with fluorescence detection (HPLC-FLD) analysis indicated a theoretical substrate saturation above solubility in water. At a relatively high concentration of 500 μg/L, AFB1 was decomposed at 10.75 μg/Lh (0.17 nmol*min−1*mg−1) at a dosage of 0.2 μM BsCotA. AFQ1 and epi-AFQ1 were identified as the initial oxidation products according to mass spectrometry (i.e., HPLC-MS, HPLC-QTOF). None of these molecules were substrates for laccase but both decomposed in buffer. However, decomposition does not seem to be due to hydration of the vinyl ether in the terminal furan ring. Genotoxicity of the formed AFB1 was assessed in several dilutions based on the de-repression of the bacterial SOS response to DNA damage indicating about 80-times reduction in toxicity when compared to AFQ1. The results of this study indicate that BsCotA has high potential for the biological detoxification of aflatoxin B1.

Drug addiction is a pervasive problem worldwide. It not only affects the abuser's life, but also poses a serious threat to public health. Accordingly, there is a strong demand for the development of novel and effective therapies for drug addiction. Considering that small-molecule drugs have only had limited success, there is great interest in developing alternative strategies that extend the reach of small-molecule-based therapies. The antibody-based trapping approach and the enzyme catalytic strategy have been considered as promising ways to reduce the euphoria of drug users by altering drug pharmacokinetics and decreasing drug concentrations in the central nervous system. However, these biological macromolecules are generally unstable and their in vivo half-lives are short. With the rapid development of gene editing technologies, it is possible to perform ex vivo gene therapy for the long-term and stable delivery of enzymes and other effector proteins, which could free abusers from frequent injections of therapeutics. By constructing programmed gene switches that regulate spatiotemporal gene expression in response to illicit drugs, this perspective proposed the concept of preventing drug addiction by the drug itself. This strategy enables the controlled release of therapeutic proteins in vivo and is expected to improve patient safety and compliance. This will open up new opportunities for next-generation medicine and hold great promise for expanding our ability to treat drug addiction. [ABSTRACT FROM AUTHOR]

Abstract Background The stability of resin–dentin interfaces is still highly questionable. The aim of this study was to evaluate the effect of Salvadora persica on resin–dentin bond durability. Materials and methods Extracted human third molars were used to provide mid-coronal dentin, which was treated with 20% Salvadora persica extract for 1 min after acid-etching. Microtensile bond strength and interfacial nanoleakage were evaluated after 24 h and 6 months. A three-point flexure test was used to measure the stiffness of completely demineralized dentin sticks before and after treatment with Salvadora persica extract. The hydroxyproline release test was also used to measure collagen degradation by endogenous dentin proteases. Statistical analysis was performed using two-way ANOVA followed by post hoc Bonferroni test and unpaired t-test. P-values 0.05). After 6 months, the bond strength of the control group decreased (p = 0.007), and nanoleakage increased (p = 0.006), while Salvadora persica group showed no significant difference in bond strength and nanoleakage compared to their 24 h groups (p > 0.05). Salvadora persica increased dentin stiffness and decreased collagen degradation (p

Livestock blood, typically considered a waste byproduct of the slaughter industry, has the potential to be a valuable resource in the environmental and agricultural industries owing to its high protein content. This study reports the mechanisms involved in developing a continuous process capable of processing 5 tons/day of livestock blood into high purity amino acid liquid fertilizer and dried protein feedstuff simultaneously. Large-scale processing units were fabricated for the ultrasonic pretreatment and solubilization of proteins, enzymatic degradation of dissolved proteins for amino acid conversion, solid-liquid separation using a membrane filter press to produce high purity amino acid liquid fertilizer, and microwave drying of the solid component to produce dry protein feedstuff. The main processing units were integrated into a continuous, efficient system. The final amino acid liquid fertilizer and dry protein feedstuff contained >20% amino acids and approximately 78% protein, respectively. An economic feasibility analysis of the integrated system based on an annual processing capacity of 3000 tons of livestock blood yielded a total annual profit of 17.4 million euros (5812 euros/ton). This study presents an efficient and profitable approach to repurposing the waste generated by slaughterhouses toward agriculture and feed production. [ABSTRACT FROM AUTHOR]

Background: The stability of resin–dentin interfaces is still highly questionable. The aim of this study was to evaluate the effect of Salvadora persica on resin–dentin bond durability. Materials and methods: Extracted human third molars were used to provide mid-coronal dentin, which was treated with 20% Salvadora persica extract for 1 min after acid-etching. Microtensile bond strength and interfacial nanoleakage were evaluated after 24 h and 6 months. A three-point flexure test was used to measure the stiffness of completely demineralized dentin sticks before and after treatment with Salvadora persica extract. The hydroxyproline release test was also used to measure collagen degradation by endogenous dentin proteases. Statistical analysis was performed using two-way ANOVA followed by post hoc Bonferroni test and unpaired t-test. P-values < 0.05 were considered statistically significant. Results: The use of Salvadora persica as an additional primer with etch-and-rinse adhesive did not affect the immediate bond strengths and nanoleakage (p > 0.05). After 6 months, the bond strength of the control group decreased (p = 0.007), and nanoleakage increased (p = 0.006), while Salvadora persica group showed no significant difference in bond strength and nanoleakage compared to their 24 h groups (p > 0.05). Salvadora persica increased dentin stiffness and decreased collagen degradation (p < 0.001) compared to their controls. Conclusion: Salvadora persica extract pretreatment of acid-etched dentin preserved resin–dentin bonded interface for 6 months. Clinical significance: Durability of resin-dentin bonded interfaces is still highly questionable. Endogenous dentinal matrix metalloproteinases play an important role in degradation of dentinal collagen within such interfaces. Salvadora persica may preserve resin-dentin interfaces for longer periods of time contributing to greater clinical success and longevity of resin composite restorations. [ABSTRACT FROM AUTHOR]

Heavy crude oil (HCO) and extra-heavy crude oil (EHCO) with high viscosity and density pose enormous challenges to the exploitation of oil reserves. While bacteria are increasingly used in biocatalytic upgrading of HCO and EHCO, less attention has been paid to the potential of fungi. The aim of this study was to ascertain the role of fungal extracellular enzymes from Aspergillus spp. In the biodegradation of EHCO and their application potential for enhanced oil recovery. A. terreus HJ2 and A. nidulans HJ4 with the ability to biodegrade HCO were previously isolated from bitumen enrichment cultures. Both strains grew well on EHCO agar plates supplemented with a small amount of soluble starch (0.2%) and yeast extract (0.3%). Extracellular enzymes from each strain separately, as well as mixtures of the enzymes, exhibited EHCO degradation activity, leading to redistribution of hydrocarbons with substantial formation of biogases and organic acids in a 7-day period. Enzymatic degradation resulted in decreased contents of resins and asphaltenes, accompanied by increased contents of saturates and aromatics. Gas chromatography–mass spectrometry revealed distinct redistribution patterns of n-alkane in the biotreated oil. Enzymatic degradation additionally caused considerable reduction in oil viscosity (by 12.7%) and heavy metal concentrations (Ni, by 44.1%; Fe, by 54.0%; V, by 31.6%). The results provide empirical evidence for the application potential of fungal extracellular enzymes from Aspergillus spp. in EHCO recovery and biocatalytic upgrading of EHCO.

Livestock blood, a major organic waste generated by the livestock industry, poses a risk of pollution due to its rapid decomposition. However, it is a potential protein source for agricultural purposes due to its protein-rich organic matter. In this study, we conducted studies on an eco-friendly, scalable, and effective protein degradation process using livestock blood to reduce waste and produce an amino acid liquid fertilizer that can be recycled for agricultural use. Ultrasonic technology was applied as a pretreatment method to improve the enzymatic hydrolysis efficiency of proteins in livestock blood, and the optimal conditions that led to 95.91% solubilization rate of hemoglobin were ultrasound duration for 30 min at an ultrasound density of 0.5 W/mL. As a result of hydrolyzing ultrasonically pretreated blood by mixing exo- and endo-type proteolytic enzymes, the optimal combination was a mixture of Savinase® 1% and Flavourzyme® 1%. After 4 h of reaction, the protein concentration was 27.8 mg/mL and the amino acid concentration was confirmed to be 54.6 mg/mL. This is about 4.2 times higher than the amino acid concentration of blood without ultrasound pretreatment, 13.1 mg/mL, and it was confirmed that sonication has a significant effect on improving protein degradation efficiency. As protein degradation increased, the viscosity of blood gradually decreased, suggesting that the physical force applied to the agitator torque diminished during the enzyme reaction; a significant correlation between protein and amino acid concentrations (biological factors) and torque (mechanical factor) was observed. Measuring torque during an enzyme reaction can confirm the extent of the enzyme reaction, so it can be used as an indicator of reaction progress when scaling up the process in the future. [ABSTRACT FROM AUTHOR]

Background: The abdominal aortic aneurysm (AAA) is defined as an increase in aortic diameter by more than 50% and is associated with a high risk of rupture and mortality without treatment. The aim of this study is to analyze the role of aortic adventitial collagen photocrosslinking by UV-A irradiation on the biomechanical profile of the aortic wall. Methods: This experimental study is structured in two parts: the first part includes in vitro uniaxial biomechanical evaluation of porcine adventitial tissue subjected to either short-term elastolysis or long-term collagenolysis in an attempt to duplicate two extreme situations as putative stages of aneurysmal degeneration. In the second part, we included biaxial biomechanical evaluation of in vitro human abdominal aortic adventitia and human AAA adventitia specimens. Biomechanical profiles were examined for porcine and human aortic tissue before and after irradiation with UV-A light (365 nm wavelength). Results: On the porcine aortic sample, the enhancing effect of irradiation was evident both on the tissue subjected to elastolysis, which had a high collagen-to-elastin ratio, and on the tissue subjected to prolonged collagenolysis despite being considerably depleted in collagen. Further, the effect of irradiation was conclusively demonstrated in the human adventitia samples, where significant post-irradiation increases in Cauchy stress (longitudinal axis: p = 0.001, circumferential axis: p = 0.004) and Young's modulus (longitudinal axis: p = 0.03, circumferential axis: p = 0.004) were recorded. Moreover, we have a stronger increase in the strengthening of the AAA adventitia samples following the exposure to UV-A irradiation (p = 0.007) and a statistically significant but not very important increase (p = 0.021) regarding the stiffness in the circumferential axis. Conclusions: The favorable effect of UV irradiation on the strength and stiffness of degraded aortic adventitia in experimental situations mimicking early and later stages of aneurysmal degeneration is essential for the development and potential success of procedures to prevent aneurysmal ruptures. The experiments on human normal and aneurysmal adventitial tissue confirmed the validity and potential success of a procedure based on exposure to UV-A radiation. [ABSTRACT FROM AUTHOR]

To enhance the degradation rate of poly (butylene adipate-co-terephthalate) (PBAT) in the natural environment and to investigate the effect of modified monomers on the molding and structure of copolyester fibers, a series of isosorbide modified PBAT (PBIAT) tetrapolyesters were synthesized and monofilaments were prepared by solid-state drawing in this work. The experimental results revealed that the introduction of isosorbide formed a partial block structure in the molecular chain, and that a significant improvement in the properties of heat resistance and degradability of the copolyester was observed with the introduction of isosorbide. In the research of fiber forming and structure-property relationship by isosorbide, it was found that although the monofilament orientation process was affected by the V-shape structure of isosorbide, the change of the crystal structure under stress was similar to that of polybutylene terephthalate (PBT). The PBIAT monofilaments showed a decrease in the strength at break affected by the introduction of isosorbide but they still met the requirements for textile applications.

Perfluoroalkyl acids (PFAAs) are considered forever chemicals, gaining increasing attention for their hazardous impacts. However, the ecological effects of PFAAs remain unclear. Environmental DNA (eDNA), as the environmental gene pool, is often collected for evaluating the ecotoxicological effects of pollutants. In this study, we found that all PFAAs investigated, including perfluorohexanoic acid, perfluorooctanoic acid, perfluorononanoic acid, and perfluorooctane sulfonate, even at low concentrations (0.02 and 0.05 mg/L), expedited the enzymatic degradation of DNA in a nonlinear dose–effect relationship, with DNA degradation fragment sizes being lower than 1,000 bp and 200 bp after 15 and 30 min of degradation, respectively. This phenomenon was attributed to the binding interaction between PFAAs and AT bases in DNA via groove binding. van der Waals force (especially dispersion force) and hydrogen bonding are the main binding forces. DNA binding with PFAAs led to decreased base stacking and right-handed helicity, resulting in loose DNA structure exposing more digestion sites for degrading enzymes, and accelerating the enzymatic degradation of DNA. The global ecological risk evaluation results indicated that PFAA contamination could cause medium and high molecular ecological risk in 497 samples from 11 contamination-hot countries (such as the USA, Canada, and China). The findings of this study show new insights into the influence of PFAAs on the environmental fates of biomacromolecules and reveal the hidden molecular ecological effects of PFAAs in the environment.

Polycyclic aromatic hydrocarbons (PAHs) are widespread, persistent, and toxic environmental pollutants. Many anthropogenic and some natural factors contribute to the spread and accumulation of PAHs in aquatic and soil systems. The effective and environmentally friendly remediation of these chemical compounds is an important and challenging problem that has kept scientists busy over the last few decades. This review briefly summarizes data on the main sources of PAHs, their toxicity to living organisms, and physical and chemical approaches to the remediation of PAHs. The basic idea behind existing approaches to the bioremediation of PAHs is outlined with an emphasis on a detailed description of the use of bacterial strains as individual isolates, consortia, or cell-free enzymatic agents.

The practical application of plastics is as indispensable as it is problematic regarding disposal. Plastics present significant opportunities in the context of circular usage and recycling. A circular economy dictates the utilization of every side stream to minimize waste. Current waste management techniques are insufficient in reducing plastic waste entering landfills, wastewater treatment systems, and the environment. Under these circumstances, plastic biodegradation has emerged as a viable and environmentally responsible approach to plastic pollution. Methods are needed for the natural degradation of plastics using microbes that can utilize plastics as their sole carbon source. Studies to enhance the catalytic activity of plastic-degrading enzymes through protein engineering approaches are a relatively new field of research. Enzymatic degradation for product creation represents a purely biological plastic recycling method in a sustainable economy. This review builds insights derived from previous studies and provides a brief overview of plastic degradation using enzymes, improvements in plastic-degrading enzyme efficiency, and stabilization via various protein engineering strategies. In addition, recent advances in plastic waste valorization technology based on systems metabolic engineering and future directions are discussed.

A promising strategy to counteract the progressing plastic pollution of the environment can involve the replacement of persistent plastics with biodegradable materials. Biodegradable polymers are enzymatically degradable by various hydrolytic enzymes. However, these materials can reach the environment in the same way as conventional plastics. Therefore, they are accessible to terrestrial, freshwater, and marine biota. Once ingested by marine organisms, highly active enzymes in their digestive tracts may break down biodegradable compounds. We incubated microparticles of five different biodegradable plastics, based on polylactictic acid (PLA), polybutylene succinate (PBS), polybutylene adipate terephthalate (PBAT) and polyhydroxybutyrate-co-valerate (PHBV), in-vitro with the gastric fluid of the edible crab Cancer pagurus and evaluated the hydrolysis rates by pH Stat titration. A plastic blend of PLA with PBAT showed the highest hydrolysis rate. The enzymes in the gastric fluid of crabs were separated by anion exchange chromatography. Fractions with carboxylesterase activity were identified using fluorescent methylumbelliferyl (MUF)-derivatives. Pooled fractions with high carboxylesterase activity also hydrolyzed a PLA/PBAT plastic blend. Carboxylesterases showed molecular masses of 40–45 kDa as determined by native gel electrophoresis (SDS-PAGE). Our study demonstrated that digestive carboxylesterases in the gastric fluid of C. pagurus exhibit a high potential for hydrolyzing certain biodegradable plastics. Since esterases are common in the digestive tract of organisms, it seems likely that other invertebrates possess the ability to hydrolyze biodegradable plastics.

ABSTRACT Cyclic lipopeptides (CLPs) are key bioactive secondary metabolites produced by some plant beneficial rhizobacteria such as Pseudomonas and Bacillus. They exhibit antimicrobial properties, promote induced systemic resistance in plants, and support key developmental traits, including motility, biofilm formation, and root colonization. However, our knowledge about the fate of lipopeptides once released in the environment and especially upon contact with neighboring rhizobacteria remains limited. Here, we investigated the enzymatic degradation of Bacillus and Pseudomonas cyclic lipopeptides by Streptomyces. We observed that Streptomyces venezuelae is able to degrade the three lipopeptides surfactin, iturin, and fengycin upon interaction with Bacillus velezensis in vitro and in planta according to specific mechanisms. S. venezuelae was also able to degrade the structurally diverse sessilin-, tolaasin-, orfamide-, xantholisin-, and putisolvin-type lipopeptides produced by Pseudomonas, indicating that this trait is likely engaged in the interaction with various competitors. Furthermore, the degradation of CLPs is associated with the release of free amino and fatty acids used by Streptomyces to sustain growth. Additionally, we hypothesize that lipopeptide-producing rhizobacteria and their biocontrol potential are impacted by the degradation of their lipopeptides as observed with the polarized motility of B. velezensis, avoiding the confrontation zone with Streptomyces and the loss of antifungal properties of degraded iturin. IMPORTANCE Here, we provide new insights into the possible fate of cyclic lipopeptides as prominent specialized metabolites from beneficial bacilli and pseudomonads once released in the soil. Our data illustrate how the B. velezensis lipopeptidome may be enzymatically remodeled by Streptomyces as important members of the soil bacterial community. The enzymatic arsenal of S. venezuelae enables an unsuspected extensive degradation of these compounds, allowing the bacterium to feed on these exogenous products via a mechanism going beyond linearization, which was previously reported as a detoxification strategy. As soils are carbon-rich and nitrogen-poor environments, we propose a new role for cyclic lipopeptides in interspecies interactions, which is to fuel the nitrogen metabolism of a part of the rhizosphere microbial community. Streptomyces and other actinomycetes, producing numerous peptidases and displaying several traits of beneficial bacteria, should be at the front line to directly benefit from these metabolites as “public goods” for microbial cooperation.

Biotechnology offers the potential for selective depolymerization of natural and synthetic fibers, isolation of components, or recovery of monomers. This progress solves the problems associated with the regeneration of monomers from synthetic fiber blends, especially when contaminated or mixed fibers are involved. In addition, the recycling of used fiber products into higher-value products not only keeps waste out of landfills but also creates economic opportunities and reduces the need to produce new synthetic fibers. Synthetic fibers can be recovered by mechanical or chemical recycling, but biotechnological solutions with enzymes offer a more environmentally friendly alternative to harsh chemicals by selectively breaking down certain chemical bonds in polymers to obtain purer monomeric building blocks. Efficient biotechnological recycling, however, depends on the specific polymer, as different enzymes, microbial colonies, fungal hyphae, etc. can process different man-made fibers. Challenges arise with any type of fiber recovery, including enzymatic degradation when suitable enzymes have not yet been discovered or when fiber blends impede accessibility and efficiency. This short review provides an overview of the possibilities of biotechnological solutions for synthetic fiber recovery. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the behavior of chitosan/quaternized chitosan fibers in media mimicking wound exudates to understand their capacities as wound dressing. Fiber analysis of the fibers using dynamic vapor sorption proved their ability to adsorb moisture up to 60% and then to desorb it as a function of humidity, indicating their outstanding breathability. Dissolution analyses showed that quaternized chitosan leached from the fibers in water and PBS, whereas only small portions of chitosan were solubilized in water. In media containing lysozyme, the fibers degraded with a rate determined by their composition and pH, reaching a mass loss of up to 47% in media of physiologic pH. Notably, in media mimicking the wound exudate during healing, they adsorbed moisture even when their mass loss due to biodegradation was high, whereas they were completely degraded in the media of normal tissues, indicating bioabsorbable dressing capacities. A mathematical model was constructed, which characterized the degradation rate and morphology changes of chitosan/quaternized chitosan fibers through analyses of dynamics in scale space, using the Theory of Scale Relativity. The model was validated using experimental data, making it possible to generalize it to the degradation of other biopolymeric systems that address wound healing. [ABSTRACT FROM AUTHOR]

Volumizing fillers aim to create or restore facial volume in fat layers. To provide strong tissue lifting and long-term persistence, gels are generally designed with stiff properties, characterized by a high storage modulus (G′). However, clinical evidence shows a discrepancy between high G′ and good lifting capacities, especially after skin tension has been exerted on the gel. To better explore the in vivo behavior of a gel, we first evaluated the elastic moduli of five commercial volumizers (RHA4, JUVVOL, RESVOL, RESLYFT, and BELVOL) in dynamic compression mode, E′. We further developed a Projection Index score based on the rheological assessment of creep in compression to mimic skin tension-induced stress relaxation (flattening). Finally, the ability of a gel to resist enzymatic degradation was analyzed with a multidose approach. Despite similar clinical indications, volumizers exhibited distinct behaviors. RHA4 and BELVOL showed the highest E′ values (resistance to strain), RHA4, JUVVOL, and RESVOL exhibited the greatest projection capacities, while JUVVOL and RHA4 offered the largest persistence to enzymatic degradation. In this article, we introduce the use of the Projection Index to efficiently assess the ability of a gel to lift tissues, thus increasing preclinical models' efficiency and reducing the need for animal studies. [ABSTRACT FROM AUTHOR]

This study investigates the enzymatic degradation processes of different classes of polyhydroxyalkanoates (PHAs), a group of biopolymers naturally synthesized by various microorganisms. Medium chain length PHAs (mcl-PHAs) are distinguished biopolymers due to their biodegradability and diverse material properties. Using quartz crystal microbalance measurements as a valuable tool for accurate real-time monitoring of the enzymatic degradation process, the research provides detailed kinetic data, describing the interaction between enzymes and substrates during the enzymatic degradation process. Thin films of poly-3-hydroxybutyrate (PHB) and polyhydroxyoctanoate copolymer (PHO), containing molar fractions of about 84% 3-hydroxyoctanoate and 16% 3-hydroxyhexanoate, were exposed to scl-depolymerases from Pseudomonas lemoignei LMG 2207 and recombinant mcl-depolymerase produced in Escherichia coli DH5α harboring the plasmid pMAD8, respectively. Analyses based on a heterogeneous kinetic model for the polymer degradation indicated a six-fold stronger adsorption equilibrium constant of mcl-depolymerase to PHO. Conversely, the degradation rate constant was approximately twice as high for scl-depolymerases acting on PHB. Finally, the study highlights the differences in enzyme-substrate interactions and degradation mechanisms between the investigated scl- and mcl-PHAs.

Environmental problems caused by plastic pollution are among the most pressing issues of our time. In recent years, metagenomics has become a powerful tool for understanding the microbial communities responsible for plastic biodegradation. In this review, recent developments and trends in metagenomics are discussed, and a comprehensive overview of the metagenomic methodology, analysis, and comparison of plastic-degrading bacteria is provided. In addition, the environmental consequences of plastic degradation are discussed, such as the impact on soil, water, and air quality, as well as the potential health risks posed by ingesting and inhaling microplastics. Possible solutions to the plastic degradation problem, such as using biodegradable materials and implementing recycling programs, are also explained. This review highlights the potential impact of metagenomics on the development of sustainable solutions to plastic pollution.

Enzymatic polyethylene terephthalate (PET) recycling processes are gaining interest for their low environmental impact, use of mild conditions, and specificity. Furthermore, PET hydrolase enzymes are continuously being discovered and engineered. In this work, we studied a PET hydrolase (PET2), initially characterized as an alkaline thermostable lipase. PET2 was produced in a fusion form with a 6-histidine tag in the N-terminal. The PET2 activity on aromatic terephthalate and new indole-based polyesters was evaluated using polymers in powder form. Compared with IsPETase, an enzyme derived from Ideonella sakaiensis, PET2 showed a lower PET depolymerization yield. However, interestingly, PET2 produced significantly higher polybutylene terephthalate (PBT) and polyhexylene terephthalate (PHT) depolymerization yields. A clear preference was found for aromatic indole-derived polyesters over non-aromatic ones. No activity was detected on Akestra™, an amorphous copolyester with spiroacetal structures. Docking studies suggest that a narrower and more hydrophobic active site reduces its activity on PET but favors its interaction with PBT and PHT. Understanding the enzyme preferences of polymers will contribute to their effective use to depolymerize different types of polyesters. [ABSTRACT FROM AUTHOR]

Background: The excellent physicochemical and biomedical properties make silk fibroin (SF) suitable for the development of biomedical materials. In this research, the silk fibroin microspheres (SFMS) were customized in two size ranges, and then carried gold nanoparticles or doxorubicin to evaluate the performance of drug loading and releasing. Embolization efficiency was evaluated in rat caudal artery and rabbit auricular artery, and the in vivo distribution of iodinated SFMS (125I/131I-SFMS) after embolization of rat hepatic artery was dynamically recorded by SPECT. Transhepatic arterial radioembolization (TARE) with 131I-SFMS was performed on rat models with liver cancer. The whole procedure of selective internal radiation was recorded with SPECT/CT, and the therapeutic effects were evaluated with 18 F-FDG PET/CT. Lastly, the enzymatic degradation was recorded and followed with the evaluation of particle size on clearance of sub-micron silk fibroin. Results: SFMS were of smooth surface and regular shape with pervasive pores on the surface and inside the microspheres, and of suitable size range for TAE. Drug-loading functionalized SFMS with chemotherapy or radio-sensitization, and the enhanced therapeutic effects were proved in treating HUH-7 cells as lasting doxorubicin release or more lethal radiation. For artery embolization, SFMS effectively blocked the blood supply; when 131I-SFMS serving as the embolic agent, the good labeling stability and embolization performance guaranteed the favorable therapeutic effects in treating in situ liver tumor. At the 5th day post TARE with 37 MBq/3 mg 131I-SFMS per mice, tumor activity was quickly inhibited to a comparable glucose metabolism level with surrounding normal liver. More importantly, for the fragments of biodegradable SFMS, smaller sized SF (< 800 nm) metabolized in gastrointestinal tract and excreted by the urinary system, while SF (> 800 nm) entered the liver within 72 h for further metabolism. Conclusion: The feasibility of SFMS as degradable TARE agent for liver cancer was primarily proved as providing multiple therapeutic potentials. [ABSTRACT FROM AUTHOR]

Polylactides (PLAs) and lactide copolymers are biodegradable, compostable, and derived from renewable resources, offering a sustainable alternative to petroleum-based synthetic polymers owing to their advantages of comparable mechanical properties with commodity plastics and biodegradability. Their hydrolytic stability and thermal properties can affect their potential for long-lasting applications. However, stereocomplex crystallization is a robust method between isomer PLAs that allows significant amelioration in copolymer properties, such as thermal stability, mechanical properties, and biocompatibility, through substantial intermolecular interactions amid l-lactyl and d-lactyl sequences, which have been the key approach to initial degradation rate and further PLA applications. It was demonstrated that the essential parameters affecting stereocomplexation are the mixing ratio and the chain length of each unit sequence. This study deals with the molecular weight, one of the specific interactions between isomers of PLAs. A solution polymerization method was applied to control molecular weight and chain architecture. The stereocomplexation was monitored with DSC. It was confirmed that the lower molecular weight polymer showed a higher degradation rate, as a hydrolyzed fragment having a molecular weight below a certain length dissolves into the water. To systematically explore the critical contribution of molecular weights, the Langmuir system was used to observe the stereocomplexation effect and the overall degradation rate. [ABSTRACT FROM AUTHOR]

Enzyme-responsive polymeric-based nanostructures are potential candidates for serving as key materials in targeted drug delivery carriers. However, the major risk in their prolonged application is fast disassembling of the short-lived polymeric-based structures. Another disadvantage is the limited accessibility of the enzyme to the moieties that are located inside the network. Here, we report on a modified environmentally responsive and enzymatically cleavable nanogel carrier that contains a hybrid network. A properly adjusted volume phase transition (VPT) temperature allowed independent shrinking of a) poly(ethylene glycol) methyl ether methacrylate (OEGMA) with di(ethylene glycol) and b) methyl ether methacrylate (MEO2MA) part of the network, and the exposition of hyaluronic acid methacrylate (MeHa) network based carboxylic groups for its targeted action with the cellular based receptors. This effect was substantial after raising temperature in typical hyperthermia-based treatment therapies. Additionally, novel tunable NGs gained an opportunity to store- and to efficient-enzyme-triggered release relatively low but highly therapeutic doses of doxorubicin (DOX) and mitoxantrone (MTX). The controlled enzymatic degradation of NGs could be enhanced by introducing more hyaluronidase enzyme (HAdase), that is usually overexpressed in cancer environments. MTT assay results revealed effective cytotoxic activity of the NGs against the human MCF-7 breast cancer cells, the A278 ovarian cancer cells and also cytocompatibility against the MCF-10A and HOF healthy cells. The obtained tunable, hybrid network NGs might be used as a useful platform for programmed delivery of other pharmaceuticals and diagnostics in therapeutic applications.

Application of thermoplastic fiber-reinforced lightweight composite materials provides a wide range of advantages that are of particular importance for the mobility sector. UD tapes composed of unidirectionally (UD) oriented inorganic fibers embedded in a thermoplastic matrix represent light-weight materials with high tensile strength. This publication addresses recycling aspects of novel UD tape made of a combination of basalt fibers and different PLA (polylactic acid) formulations. The kinetics of enzyme-based separation of polymer from the fiber were investigated. Different types of UD tapes with a thickness of 270–290 µm reinforced with basalt fiber weight ratios ranging between 51 and 63% were incubated at 37 °C in buffer solution (pH 7.4) containing proteinase K. The influence of enzyme concentration, tape weight per incubation tube, proteinase K activators, and tape types on the rate of enzymatic decomposition was investigated. Enzyme activity was measured by analyzing lactate concentration with lactate dehydrogenase and by measuring weight loss of the composite material. The rate of lactate release increased in the first 30 min of incubation and remained stable for at least 90 min. Weight loss of 4% within 4 h was achieved for a tape with 56% (w/w) fiber content. For a sample with a surface area of 3 cm2 in a buffer volume of 10 mL, the rate of lactate release as a function of enzyme concentration reached saturation at 300 µg enzyme/mL. With this enzyme concentration, the rate of lactate release increased in a linear manner for tape surface areas between 1 and 5 cm2. Four tapes with different PLA types were treated with the enzyme for 17 h. Weight loss ranged between 7 and 24%. Urea at a concentration of 0.5% (w/v) increased lactate release by a factor of 9. Pretreatment of tapes in alkaline medium before enzymatic degradation increased weight loss to 14% compared to 5% without pretreatment. It is concluded that enzymatic PLA hydrolysis from UD tapes is a promising technology for the release of basalt fibers after alkaline pretreatment or for the final cleaning of basalt fibers.

Among biodegradable polymers, polylactides (PLAs) have attracted considerable interest because the monomer can be produced from renewable resources. Since their initial degradability strongly affects commercial application fields, it is necessary to manage the degradation properties of PLAs to make them more commercially attractive. To control their degradability, poly(lactide-co-glycolide) (PLGA) copolymers of glycolide and isomer lactides (LAs) were synthesized, and their enzymatic and alkaline degradation rates of PLGA monolayers as functions of glycolide acid (GA) composition were systematically investigated by the Langmuir technique. The results showed that the alkaline and enzymatic degradations of PLGA monolayers were faster than those of l-polylactide (l-PLA), even though proteinase K is selectively effective in the l-lactide (l-LA) unit. Alkaline hydrolysis was strongly affected by their hydrophilicity, while the surface pressure of monolayers for enzymatic degradations was a major factor. [ABSTRACT FROM AUTHOR]

Biological degradation of mycotoxins is a promising environmentally-friendly alternative to chemical and physical detoxification methods. To date, a lot of microorganisms able to degrade them have been described; however, the number of studies determining degradation mechanisms and irreversibility of transformation, identifying resulting metabolites, and evaluating in vivo efficiency and safety of such biodegradation is significantly lower. At the same time, these data are crucial for the evaluation of the potential of the practical application of such microorganisms as mycotoxin-decontaminating agents or sources of mycotoxin-degrading enzymes. To date, there are no published reviews, which would be focused only on mycotoxin-degrading microorganisms with the proved irreversible transformation of these compounds into less toxic compounds. In this review, the existing information about microorganisms able to efficiently transform the three most common fusariotoxins (zearalenone, deoxinyvalenol, and fumonisin B1) is presented with allowance for the data on the corresponding irreversible transformation pathways, produced metabolites, and/or toxicity reduction. The recent data on the enzymes responsible for the irreversible transformation of these fusariotoxins are also presented, and the promising future trends in the studies in this area are discussed. [ABSTRACT FROM AUTHOR]

Many strategies have been adopted to prepare silica materials with highly controlled structures, typically using sol–gel chemistry. Frequently, the alkoxysilanes used in sol–gel chemistry are based on monoalcohols, e.g., Si(OEt)4. The structural control over silica synthesis achieved by these precursors is highly sensitive to pH and solvency. Alkoxysilanes derived from the sugar alcohol glycerol (diglycerylsilane) react more slowly and with much less sensitivity to pH. We report that, in the presence of cooled aqueous starch solutions, glyceroxysilanes undergo transesterification with the sugars on starch, leading to (hollow) microtubules resembling worms of about 400 nm in diameter. The tubes arise from the pre-assembly of starch bundles, which occurs only well below room temperature. It is straightforward to treat the first-formed starch/silica composite with the enzyme amylase to, in a programmed fashion, increasingly expose porosity, including the worm morphology, while washing away untethered silica and digested starch to leave an open, highly porous materials. Sintering at 600 °C completely removes the starch silane moieties. [ABSTRACT FROM AUTHOR]

Introduction: Poly(1,3-trimethylene carbonate) (PTMC) is a flexible amorphous polymer with good degradability and biocompatibility. The degradation of PTMC is critical for its application as a degradable polymer, more convenient and easy-to-control cross-linking strategies for preparing PTMC are required.Methods: The blends of poly(trimethylene carbonate) (PTMC) and cross-linked poly(ethylene glycol) diacrylate (PEGDA) were prepared by mixing photoactive PEGDA and PTMC and subsequently photopolymerizing the mixture with uv light. The physical properties and in vitro enzymatic degradation of the resultant PTMC/cross-linked PEGDA blends were investigated.Results: The results showed that the gel fraction of PTMC/cross-linked PEGDA blends increased while the swelling degree decreased with the content of PEGDA dosage. The results of in vitro enzymatic degradation confirmed that the degradation of PTMC/cross-linked PEGDA blends in the lipase solution occurred under the surface erosion mechanism, and the introduction of the uv cross-linked PEGDA significantly improved the resistance to lipase erosion of PTMC; the higher the cross-linking degree, the lower the mass loss.Discussion: The results indicated that the blends/cross-linking via PEGDA is a simple and effective strategy to tailor the degradation rate of PTMC.

Livestock blood, a major organic waste generated by the livestock industry, poses a risk of pollution due to its rapid decomposition. However, it is a potential protein source for agricultural purposes due to its protein-rich organic matter. In this study, we conducted studies on an eco-friendly, scalable, and effective protein degradation process using livestock blood to reduce waste and produce an amino acid liquid fertilizer that can be recycled for agricultural use. Ultrasonic technology was applied as a pretreatment method to improve the enzymatic hydrolysis efficiency of proteins in livestock blood, and the optimal conditions that led to 95.91% solubilization rate of hemoglobin were ultrasound duration for 30 min at an ultrasound density of 0.5 W/mL. As a result of hydrolyzing ultrasonically pretreated blood by mixing exo- and endo-type proteolytic enzymes, the optimal combination was a mixture of Savinase® 1% and Flavourzyme® 1%. After 4 h of reaction, the protein concentration was 27.8 mg/mL and the amino acid concentration was confirmed to be 54.6 mg/mL. This is about 4.2 times higher than the amino acid concentration of blood without ultrasound pretreatment, 13.1 mg/mL, and it was confirmed that sonication has a significant effect on improving protein degradation efficiency. As protein degradation increased, the viscosity of blood gradually decreased, suggesting that the physical force applied to the agitator torque diminished during the enzyme reaction; a significant correlation between protein and amino acid concentrations (biological factors) and torque (mechanical factor) was observed. Measuring torque during an enzyme reaction can confirm the extent of the enzyme reaction, so it can be used as an indicator of reaction progress when scaling up the process in the future.

BackgroundLignocellulose biomass is known as a recalcitrant material towards enzymatic hydrolysis, increasing the process cost in biorefinery. In nature, filamentous fungi naturally degrade lignocellulose, using an arsenal of hydrolytic and oxidative enzymes. Assessment of enzyme hydrolysis efficiency generally relies on the yield of glucose for a given biomass. To better understand the markers governing recalcitrance to enzymatic degradation, there is a need to enlarge the set of parameters followed during deconstruction.ResultsIndustrially-pretreated biomass feedstocks from wheat straw, miscanthus and poplar were sequentially hydrolysed following two steps. First, standard secretome from Trichoderma reesei was used to maximize cellulose hydrolysis, producing three recalcitrant lignin-enriched solid substrates. Then fungal secretomes from three basidiomycete saprotrophs (Laetisaria arvalis, Artolenzites elegans and Trametes ljubarskyi) displaying various hydrolytic and oxidative enzymatic profiles were applied to these recalcitrant substrates, and compared to the T. reesei secretome. As a result, most of the glucose was released after the first hydrolysis step. After the second hydrolysis step, half of the remaining glucose amount was released. Overall, glucose yield after the two sequential hydrolyses was more dependent on the biomass source than on the fungal secretomes enzymatic profile. Solid residues obtained after the two hydrolysis steps were characterized using complementary methodologies. Correlation analysis of several physico-chemical parameters showed that released glucose yield was negatively correlated with lignin content and cellulose crystallinity while positively correlated with xylose content and water sorption. Water sorption appears as a pivotal marker of the recalcitrance as it reflects chemical and structural properties of lignocellulosic biomass.ConclusionsFungal secretomes applied to highly recalcitrant biomass samples can further extend the release of the remaining glucose. The glucose yield can be correlated to chemical and physical markers, which appear to be independent from the biomass type and secretome. Overall, correlations between these markers reveal how nano-scale properties (polymer content and organization) influence macro-scale properties (particle size and water sorption). Further systematic assessment of these markers during enzymatic degradation will foster the development of novel cocktails to unlock the degradation of lignocellulose biomass.

The influence of storage conditions on the mechanical recycling of pre-consumer waste (PRE-CW) from the manufacture of multilayer packaging films starting from starch compounds using a renewable-based polymer with PCL and PBAT, which are biodegradable conventional-based polyesters, was studied. It was found that, unlike materials based on conventional-origin polymers that accumulate in the environment for hundreds of years, the studied compounds degraded, even in the solid state, duringstorage in unventilated spaces and during the rainy hot summers with alternatingheat and rain. The degradation of the mechanically recycled compounds obtained from PRE-CW stored in such conditions was highlighted by the comparative analysis with the primary compounds, which proved the following: specific FTIR spectra changes; 2–3-times higher melt fluidity than for primary compounds; melting in successive processes over the entire positive temperatures range, up to 115 °C, such as in cases of compositional de-mixing of incompatible blends, faced to a single melting endotherm with a maximum at around 120 °C for the primar thermal degradation with the movement of the main destruction stages towards higher temperatures; a high quantity residue at 750 °C in air; dispersed mechanical resistance properties y compounds; crystallization at temperatures 10 °C–15 °C higher. The elimination of storage before the mechanical recycling of the pre-consumer waste from this type of polymeric compound fabrication is a way to increase the mechanical recycling efficiency while obtaining new materials with functional properties required by the applications. [ABSTRACT FROM AUTHOR]

Minimally invasive hyaluronan (HA) tissue fillers are routinely employed to provide tissue projection and correct age-related skin depressions. HA fillers can advantageously be degraded by hyaluronidase (HAase) administration in case of adverse events. However, clear guidelines regarding the optimal dosage and mode of administration of HAase are missing, leaving a scientific gap for practitioners in their daily practice. In this study, we implemented a novel rheological procedure to rationally evaluate soft tissue filler degradability and optimize their degradation kinetics. TEOSYAL RHA® filler degradation kinetics in contact with HAase was monitored in real-time by rheological time sweeps. Gels were shown to degrade as a function of enzymatic activity, HA concentration, and BDDE content, with a concomitant loss of their viscoelastic properties. We further demonstrated that repeated administration of small HAase doses improved HA degradation kinetics over large single doses. Mathematical analyses were developed to evaluate the degradation potential of an enzyme. Finally, we tuned the optimal time between injections and number of enzymatic units, maximizing degradation kinetics. In this study, we have established a scientific rationale for the degradation of HA fillers by multidose HAase administration that could serve as a basis for future clinical management of adverse events. [ABSTRACT FROM AUTHOR]

The large amount of waste synthetic polyester plastics has complicated waste management and also endangering the environment due to improper littering. In this study, a novel carboxylesterase from Thermobacillus composti KWC4 (Tcca) was identified, heterologously expressed in Escherichia coli, purified and characterized with various plastic substrates. Irregular grooves were detected on polybutylene adipate terephthalate (PBAT) film by scanning electron microscopy (SEM) after Tcca treatment, and Tcca can also hydrolyze short–chain diester bis(hydroxyethyl) terephthalate (BHET). The optimal pH and temperature for Tcca were 7.0 and 40 °C, respectively. In order to explore its catalytic mechanism and improve its potential for plastic hydrolysis, we modeled the protein structure of Tcca and compared it with its homologous structures, and we identified positions that might be crucial for the binding of substrates. We generated a variety of Tcca variants by mutating these key positions; the variant F325A exhibited a more than 1.4–fold improvement in PBAT hydrolytic activity, and E80A exhibited a more than 4.1–fold increase in BHET activity when compared to the wild type. Tcca and its variants demonstrated future applicability for the recycling of bioplastic waste containing a PBAT fraction. [ABSTRACT FROM AUTHOR]

Abstract Mycotoxins are generally found in food, feed, dairy products, and beverages, subsequently presenting serious human and animal health problems. Not surprisingly, mycotoxin contamination has been a worldwide concern for many research studies. In this regard, many biological, chemical, and physical approaches were investigated to reduce and/or remove contamination from food and feed products. Biological detoxification processes seem to be the most promising approaches for mycotoxins removal from food. The current review details the newest progress in biological detoxification (adsorption and metabolization) through microorganisms, their biofilms, and enzymatic degradation, finally describing the detoxification mechanism of many mycotoxins by some microorganisms. This review also reports the possible usage of microorganisms as mycotoxins’ binders in various food commodities, which may help produce mycotoxins-free food and feed.

Traditional plastics, predominantly derived from petrochemicals, are extensively utilized in modern industry and daily life. However, inadequate management and disposal practices have resulted in widespread environmental contamination, with polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, and polystyrene being the most prevalent pollutants. Biological methods for plastic degradation have garnered significant attention due to their cost-effectiveness and potential for resource recovery, positioning them as promising strategies for sustainable plastic waste management. While polyethylene terephthalate, characterized by its relatively less stable C-O bonds, has been extensively studied and demonstrates significant potential for biodegradation. In contrast, the biodegradation of other plastics remains a significant challenge due to the inherent stability of their C-C backbone structures. This review comprehensively examines the state-of-the-art biotechnology for treating these traditional plastics, focusing on: (1) the roles of specific microorganisms and enzymes, their taxonomic classifications, and the metabolic pathways involved in plastic biodegradation; and (2) a proposed two-stage hybrid approach integrating physicochemical and biological processes to enhance the biodegradation or upcycling of these traditional plastics. Additionally, the review highlights the critical role of multi-omics approaches and tailored strategies in enhancing the efficiency of plastic biodegradation while examining the impact of plastic molecular structures and additives on their degradation potential. It also addresses key challenges and delineates future research directions to foster the development of innovative biological methods for the effective and sustainable management of plastic waste. [ABSTRACT FROM AUTHOR]

Polyurethanes (PUR) are durable synthetic polymers widely used in various industries, contributing significantly to global plastic consumption. PUR pose unique challenges in terms of degradability and recyclability, as they are characterised by intricate compositions and diverse formulations. Additives and proprietary structures used in commercial PUR formulations further complicate recycling efforts, making the effective management of PUR waste a daunting task. In this review, we delve into the complex challenge of enzymatic degradation of PUR, focusing on the structural and functional attributes of both enzymes and PUR. We also present documented native enzymes with reported efficacy in hydrolysing specific bonds within PUR, analysis of these enzyme structures, reaction mechanisms, substrate specificity, and binding site architecture. Furthermore, we propose essential features for the future redesign of enzymes to optimise PUR biodegradation efficiency. By outlining prospective research directions aimed at advancing the field of enzymatic biodegradation of PUR, we aim to contribute to the development of sustainable solutions for managing PUR waste and reducing environmental pollution. [ABSTRACT FROM AUTHOR]

Cutinase were immobilized on Janus porous microspheres to produce enzyme-anchored microreactors that performed well in degrading PET and DLN nanoplastics. [Display omitted] • A microreactor enzymatic strategy was used for nanoplastic remediation in water. • Janus microspheres, developed from block copolymers, were used as enzyme carriers. • Cutinase-anchored microspheres enable efficient degradation akin to free cutinase. • High efficacy was maintained over multiple cycles, showing practical potential. While enzymatic degradation has proven to be an effective way of remediating nanoplastic-related pollution, the practical deployment of this technique is hampered by concerns over enzyme stability, costs, and the low concentration of nanoplastics in natural settings. In this study, we unveil a facile microreactor-enhanced method that improves the effective remediation capacity of cutinase for nanoplastic-polluted water systems. Our approach leverages the self-assembly capabilities of block copolymers within microfluidic droplets to fabricate Janus microspheres with distinct dual-porosity features, which have an enzyme loading capacity of up to 103.8 mg cutinase/g microsphere. The cutinase-anchored microspheres can act as microreactors to capture and degrade nanoplastics. Despite its lower enzymatic activity, the immobilized cutinase exhibits degradation performance comparable to that of its free enzyme counterpart. Moreover, it displays good operational stability over six degradation cycles. Therefore, our findings shed some light on achieving more efficient and cost-effective enzymatic nanoplastic remediation. [ABSTRACT FROM AUTHOR]