Efficiency of an alkaline, thermostable, detergent compatible, and organic solvent tolerant lipase with hydrolytic potential in biotreatment of wastewater

A comprehensive review of PbO2 electrodes in electrocatalytic degradation of organic pollutants

This paper provides a systematic review of recent advancements in PbO2 electrodes for the electrocatalytic degradation of organic pollutants, emphasizing innovative breakthroughs and key technological optimizations in this domain. This work analyzes PbO2 electrode fabrication methods, assessing strengths/weaknesses, and summarizes recent advances in surface modification. Atomic-scale strategies such as elemental doping, composite oxides, and nanomaterial coupling, enhance its catalytic performance. Kinetic modeling and characterization confirm the improved efficiency and durability in organic contaminant mineralization. Kinetic and experimental analyses demonstrate the high efficiency and stability of modified PbO2 electrodes in degrading organic pollutants. Industrial feasibility analysis indicates that the PbO2 electrode demonstrates technical robustness, economic viability, and scalability for industrial implementation. This work elucidates direct/indirect oxidation mechanisms in electrocatalysis, revealing correlations between surface reactive sites and active oxidant generation, guiding electrode design optimization. Looking ahead, this paper proposes innovative trajectories for PbO2 electrode technology, such as exploring novel modified materials, intelligently designing hierarchical architectures, and integrating advanced systems with smart control. These directions aim to promote its widespread use in environmental protection for more efficient and eco-friendly organic pollutant treatment. This review enriches the theoretical framework for PbO2 electrode electrocatalytic degradation of organic contaminants and offers references and inspirations for future research.

Enhanced solubility, bioaccessibility, and antioxidant activity of curcumin via lipase complexation: Structural insights and stability assessment

Curcumin, a bioactive compound with diverse therapeutic properties, faces challenges in clinical applications owing to its limited solubility and poor bioaccessibility. This study proposes a novel strategy to enhance the aqueous solubility, bioaccessibility, and antioxidant potential of curcumin by complexation with lipase (PersiLip1). The optimal condition for complex formation was determined to be pH 7.0, resulting in a 90-fold increase in solubility, reaching 96.92 %. Antioxidant activity assays (ABTS and DPPH) revealed significant radical scavenging capacity. Structural characterization, including Scanning Electron Microscopy (SEM), Fourier-Transform Infrared Spectroscopy (FTIR), and X-Ray Diffraction (XRD), indicated a notable transformation of curcumin from its crystalline to amorphous state. Atomic Force Microscopy (AFM) confirmed the formation of larger, stable molecular assemblies, with a particle size increase from 4.68 nm (free curcumin) to 121 nm (Cur-Lip complex). Dynamic Light Scattering (DLS) analysis revealed a further increase in the particle size to 3214.10 nm, coupled with a reduced Polydispersity Index (PDI) of 0.23, suggesting enhanced homogeneity. Zeta potential analysis showed a reduction in surface charge. Storage stability assessments confirmed the sustained solubility of the Cur-Lip complex for over 30 days. These findings highlight lipase-assisted complexation as an effective strategy for enhancing the therapeutic potential of curcumin.

Biological modification and industrial applications of microbial lipases: A general review

With the rapid development of industrialization and modern science, lipase has garnered pervasive attention. Lipases (EC 3.1.1.3) are enzymes exhibiting strong substrate specificity, high stereoselectivity, and solvent stability, which renders them a crucial biocatalyst. However, natural lipases often cannot meet the requirements of application and research in terms of activity, enantioselectivity, or thermal stability. With the continuous advancement of genetic engineering and protein engineering technologies, exploring efficient enzyme molecular modification techniques is a major task of enzyme engineering. We here review the current research status and progress of molecular modification techniques for lipases, including directed evolution, rational design, semi-rational design, and immobilization. Additionally, this article analyses lipase application prospects in food processing, environment, medical and pharmaceutical, cosmetics, and other fields. This article provides comprehensive information for the molecular modification and application research of lipases and contributes to providing reference for researchers in relevant fields.

Carboxylated nanocellulose from quinoa husk for enhanced protease immobilization and stability of protease in biotechnological applications

Herein, an efficient and feasible approach was developed to oxidize low-cost agricultural waste (quinoa husk, QS) for the synthesis of carboxylated nanocellulose (CNC). The as-prepared rod-like CNCs (average diameter of 10 nm and length of 103 nm) with a high specific surface area (173 m2/g) were utilized for the immobilization of a model protease enzyme (PersiProtease1) either physically or via covalent attachment. For chemical immobilization, CNCs were firstly functionalized with N, N'-dicyclohexylcarbodiimide (DCC) to provide DCNCs nanocarrier which could covalently bond to enzyme trough nucleophilic substitution reaction and formation of the amide bond between DCNCs and enzyme. The immobilization efficiency, activity, stability, kinetic parameters, and reusability of covalently attached and physically immobilized PersiProtease1 were similar to those of the free enzyme. Enzyme immobilization resulted in higher thermal stability of the enzyme at elevated temperatures (> 80 °C), and the covalently immobilized enzyme displayed higher reusability than its physically immobilized form (56% vs. 37% activity, after 15 consecutive cycles), which would be rooted in a more tightly attached and less leached enzyme in the case of PersiProtease1/DCNCs. This study demonstrates the significance of using agricultural by-products and the enhanced performance and stability of immobilized proteases.

Metagenomic exploration and computational prediction of novel enzymes for polyethylene terephthalate degradation

As a global environmental challenge, plastic pollution raises serious ecological and health concerns owing to the excessive accumulation of plastic waste, which disrupts ecosystems, harms wildlife, and threatens human health. Polyethylene terephthalate (PET), one of the most commonly used plastics, has contributed significantly to this growing crisis. This study offers a solution for plastic pollution by identifying novel PET-degrading enzymes. Using a combined approach of computational analysis and metagenomic workflow, we identified a diverse array of genes and enzymes linked to plastic degradation. Our study identified 1305,282 unmapped genes, 36,000 CAZymes, and 317 plastizymes in the soil samples were heavily contaminated with plastic. We extended our approach by training machine learning models to discover candidate PET-degrading enzymes. To overcome the scarcity of known PET-degrading enzymes, we used a Generative Adversarial Network (GAN) model for dataset augmentation and a pretrained deep Evolutionary Scale Language Model (ESM) to generate sequence embeddings for classification. Finally, 21 novel PET-degrading enzymes were identified. These enzymes were further validated through active site analysis, amino acid composition analysis, and 3D structure comparison. Additionally, we isolated bacterial strains from contaminated soils and extracted plastizymes to demonstrate their potential for environmental remediation. This study highlights the importance of biotechnological solutions for plastic pollution, emphasizing scalable, cost-effective processes and the integration of computational and metagenomic methods.

Deciphering styrene oxide tolerance mechanisms in Gluconobacter oxydans mutant strain

Chemical production wastewater contains large amounts of organic solvents (OSs), which pose a significant threat to the environment. In this study, a 10 g·L-1 styrene oxide tolerant strain with broad-spectrum OSs tolerance was obtained via adaptive laboratory evolution. The mechanisms underlying the high OS tolerance of tolerant strain were investigated by integrating physiological, multi-omics, and genetic engineering analyses. Physiological changes are one of the main factors responsible for the high OS tolerance in mutant strains. Moreover, the P-type ATPase GOX_RS04415 and the LysR family transcriptional regulator GOX_RS04700 were also verified as critical genes for styrene oxide tolerance. The tolerance mechanisms of OSs can be used in biocatalytic chassis cell factories to synthesize compounds and degrade environmental pollutants. This study provides new insights into the mechanisms underlying the toxicological response to OS stress and offers potential targets for enhancing the solvent tolerance of G. oxydans.

In silico design of multipoint mutants for enhanced performance of Thermomyces lanuginosus lipase for efficient biodiesel production

BACKGROUND

Biodiesel, an emerging sustainable and renewable clean energy, has garnered considerable attention as an alternative to fossil fuels. Although lipases are promising catalysts for biodiesel production, their efficiency in industrial-scale application still requires improvement.

RESULTS

In this study, a novel strategy for multi-site mutagenesis in the binding pocket was developed via FuncLib (for mutant enzyme design) and Rosetta Cartesian_ddg (for free energy calculation) to improve the reaction rate and yield of lipase-catalyzed biodiesel production. Thermomyces lanuginosus lipase (TLL) with high activity and thermostability was obtained using the Pichia pastoris expression system. The specific activities of the mutants M11 and M21 (each with 5 and 4 mutations) were 1.50- and 3.10-fold higher, respectively, than those of the wild-type (wt-TLL). Their corresponding melting temperature profiles increased by 10.53 and 6.01 °C, [Formula: see text] (the temperature at which the activity is reduced to 50% after 15 min incubation) increased from 60.88 to 68.46 °C and 66.30 °C, and the optimum temperatures shifted from 45 to 50 °C. After incubation in 60% methanol for 1 h, the mutants M11 and M21 retained more than 60% activity, and 45% higher activity than that of wt-TLL. Molecular dynamics simulations indicated that the increase in thermostability could be explained by reduced atomic fluctuation, and the improved catalytic properties were attributed to a reduced binding free energy and newly formed hydrophobic interaction. Yields of biodiesel production catalyzed by mutants M11 and M21 for 48 h at an elevated temperature (50 °C) were 94.03% and 98.56%, respectively, markedly higher than that of the wt-TLL (88.56%) at its optimal temperature (45 °C) by transesterification of soybean oil.

CONCLUSIONS

An integrating strategy was first adopted to realize the co-evolution of catalytic efficiency and thermostability of lipase. Two promising mutants M11 and M21 with excellent properties exhibited great potential for practical applications for in biodiesel production.

Revealing the contradiction between DLVO/XDLVO theory and membrane fouling propensity for oil-in-water emulsion separation

Oil fouling is the crucial issue for the separation of oil-in-water emulsion by membrane technology. The latest research found that the membrane fouling rate was opposite to the widely used theoretical prediction by Derjaguin-Landau-Verwey-Overbeek (DLVO) or extended DLVO (XDLVO) theory. To interpret the contradiction, the molecular dynamics was adopted to explore the molecular behavior of oil and emulsifier (Tween 80) at membrane interface with the assistance of DLVO/XDLVO theory and membrane fouling models. The decreased flux attenuation and fitting of fouling models proved that the existence of Tween 80 effectively alleviated membrane fouling. Conversely, DLVO/XDLVO theory predicted that the membrane fouling should be exacerbated with the increase of Tween 80 concentration in O/W emulsion. This contradiction originated from the different interaction energy between oil/Tween 80 molecules and polyether sulfone (PES) membrane. The favorable free energy of Tween 80 was resulted from the sulfuryl groups in PES and hydrogen bonds (O-H…O) formation further strengthened the interaction. Therefore, Tween 80 could preferentially adsorb on membrane surface and form an isolation layer by demulsification and steric hindrance and resist the aggregation of oil, which effectively alleviated membrane fouling. This study provided a new insight in the interpretation of interaction in O/W emulsion.

Potential of Antarctic lipase from Acinetobacter johnsonii Ant12 for treatment of lipid-rich wastewater: screening, production, properties and applications

The present study aimed to screen and optimize lipase production by the Antarctic strain Acinetobacter johnsonii Ant12 for lipid-rich wastewater treatment. Lipase production was successfully enhanced threefold through optimization of culture conditions. The optimum crude lipase activity was observed at 50 °C with high stability in a wide temperature range. The lipase also exhibited high activity and stability in the presence of solvents, metal ions, and surfactants. The crude lipase was used for the treatment of lipid-rich wastewater, which poses a significant challenge, as traditional removal methods are often inefficient or non-eco-friendly. In this study, bioaugmentation with Ant12 resulted in substantial lipid reduction in synthetic as well as real-world wastewater. Multiple linear regression analysis showed that lipid concentration and time were the most significant factors influencing lipid degradation. Bioaugmentation of real-world wastewater with Ant12 cells resulted in 84% removal of lipids in 72 h, while its crude lipase degraded 73.7% of lipids after 24 h. Thus, the specific rate of lipid degradation was higher for crude lipase (0.095/h) than the whole cell treatment (0.031/h). Economic analysis revealed that crude lipase production was much cheaper, faster and more eco-friendly than purified or partially purified lipase production, which justifies its use in wastewater treatment. The high activity of enzyme also implicates its application as a detergent additive. In our knowledge, it is the first study to establish A. johnsonii isolate from Antarctica for lipid-rich wastewater treatment.