Combining technology with liquid-formulated lipases for in-spec biodiesel production

Artificial antibody-antigen-directed immobilization of α-amylase to hydrolyze starch for cascade reduction of 2-nitro-4-methylphenol to 2-amino-4-methylphenol

Nitrophenol is a hazardous substance that poses a threat to the environment and human health, and its treatment has attracted widespread attention. The purpose of this study is to establish an environmentally friendly α-amylase system for the hydrolysis of starch to reduce nitrophenol to aminophenol through cascade reactions. The α-amylase system was obtained through artificial antibody-antigen-directed immobilization, including the synthesis of artificial antibodies, synthesis of artificial antigens, and affinity assembly. In this process, catechol and protocatechuic aldehyde were used to prepare artificial antibodies and artificial antigens respectively through polymerization and Schiff base reactions. Then, artificial antibodies captured the catechol in the artificial antigen structure to form immobilized α-amylases. Compared with free α-amylase, the immobilized α-amylase showed a good reusability and excellent regenerative ability. Subsequently, the immobilized α-amylase were used in the reaction of catalyzing starch hydrolysis to synthesize 2-amino-4-methylphenol, and the yield of 2-amino-4-methylphenol was 58.88 ± 0.19 %. After 5 consecutive catalytic reactions, a yield of 47.61 ± 1.27 % can still be achieved.

Biomimetic immobilization of α-glucosidase inspired by antibody-antigen specific recognition for catalytic preparation of 4-methylumbelliferone

Immobilization technology plays an important role in enhancing enzyme stability and environmental adaptability. Despite its rapid development, this technology still encounters many challenges such as enzyme leakage, difficulties in large-scale implementation, and limited reusability. Drawing inspiration from natural paired molecules, this study aimed to establish a method for immobilized α-glucosidase using artificial antibody-antigen interaction. The proposed method consists of three main parts: synthesis of artificial antibodies, synthesis of artificial antigens, and assembly of the artificial antibody-antigen complex. The critical step in this method involves selecting a pair of structurally similar compounds: catechol as a template for preparing artificial antibodies and protocatechualdehyde for modifying the enzyme to create the artificial antigens. By utilizing the same functional groups in these compounds, specific recognition of the antigen by the artificial antibody can be achieved, thereby immobilizing the enzymes. The results demonstrated that the immobilization amount, specific activity, and enzyme activity of the immobilized α-glucosidase were 25.09 ± 0.10 mg/g, 5.71 ± 0.17 U/mgprotein and 143.25 ± 1.71 U/gcarrier, respectively. The immobilized α-glucosidase not only exhibited excellent reusability but also demonstrated remarkable performance in catalyzing the hydrolysis of 4-methylumbelliferyl-α-D-glucopyranoside.

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.

Methyl oleate for plant protection products formulations: Enzymatic synthesis, reaction kinetics and application testing

This study presents a solvent-free enzymatic approach for the synthesis of fatty acid methyl esters (FAMEs), such as methyl oleate, for their application as adjuvant in plant protection products (PPP) formulations. The direct esterification between free fatty acid and methanol was optimized to achieve 98% acid conversion. The kinetics of this conversion was accurately described by a simple second order mechanism and non-linear regression was applied to calculate the rate constants of the forward and backward reactions based on full progress curves data. The rate constant of the forward reaction (synthesis) was one order of magnitude higher than the backward reaction (hydrolysis) and favored formation of the target methyl ester product, rendering the removal of water unnecessary. Enzymatically synthesized methyl oleate was benchmarked against the chemically synthesized compound, showing matching results in terms of stability, spreadability and emulsifying capacity in plant care formulations. The enzymatic synthesis of FAMEs under solvent free conditions allows to achieve a safer and more sustainable character for carrier solvents in PPP formulations.

The effects of the chemical modification on immobilized lipase features are affected by the enzyme crowding in the support

In this article, we have analyzed the interactions between enzyme crowding on a given support and its chemical modification (ethylenediamine modification via the carbodiimide route and picryl sulfonic (TNBS) modification of the primary amino groups) on the enzyme activity and stability. Lipase from Thermomyces lanuginosus (TLL) and lipase B from Candida antarctica (CALB) were immobilized on octyl-agarose beads at two very different enzyme loadings, one of them exceeding the capacity of the support, one well under this capacity. Chemical modifications of the highly loaded and lowly loaded biocatalysts gave very different results in terms of activity and stability, which could increase or decrease enzyme activity depending on the enzyme support loading. For example, both lowly loaded biocatalysts increased their activity after modification while the effect was the opposite for the highly loaded biocatalysts. Additionally, the modification with TNBS of highly loaded CALB biocatalyst increased its stability while decrease the activity.

Biocatalytic production of biolubricants: Strategies, problems and future trends

The increasing worries by the inadequate use of energy and the preservation of nature are promoting an increasing interest in the production of biolubricants. After discussing the necessity of producing biolubricants, this review focuses on the production of these interesting molecules through the use of lipases, discussing the different possibilities (esterification of free fatty acids, hydroesterification or transesterification of oils and fats, transesterification of biodiesel with more adequate alcohols, estolides production, modification of fatty acids). The utilization of discarded substrates has special interest due to the double positive ecological impact (e.g., oil distillated, overused oils). Pros and cons of all these possibilities, together with general considerations to optimize the different processes will be outlined. Some possibilities to overcome some of the problems detected in the production of these interesting compounds will be also discussed.

Efficient Expression of Candida antarctica Lipase B in Pichia pastoris and Its Application in Biodiesel Production

Lipase B from Candida antarctica (CALB) is an important biocatalyst with many potential applications. However, original CALB is usually with lower enzyme activity and also costly to produce from Candida antarctica; hence, it is often necessary to prepare recombinant CALB through gene heterologous expression. In this research, seven promoters and five signal peptides were compared respectively for expressing codon-optimized CALB in Pichia pastoris, and then recombinant P. pastoris containing 3 copies of calb gene were obtained by screening with high concentrations of antibiotics under the condition of the optimal combination. In a 1.3-L bioreactor, the maximum CALB activity and total protein content reached 444.46 ± 18.81 U/mL and 5.41 ± 0.1 g/L, respectively, after about 9 days of incubation in FM22 medium, which were 34 times and 20 times higher than the initial strains, respectively. In addition, the obtained CALB was used to catalyze the transesterification of acidified gutter oil with methanol, suggesting a promising pathway to convert waste or low quality of bio-oil feedstocks with high amount of free fatty acids into biodiesel by using recombinant CALB as catalyst. The results can provide with a good reference for efficient expression of CALB and enhancing lipase production in P. pastoris. It is supposed to bring with new possibility for the bio-production of other valuable proteins.

Moving towards the Application of Biocatalysis in Food Waste Biorefinery

Waste valorization is an important strategy to reduce environmental pollution and dependency on petroleum-based fuels. In this regard, utilization of food waste as a versatile and low-cost resource is important. Several advanced catalytic methods for the valorization of food waste have been widely investigated for the production of liquid biofuels. Along this line, chemical catalysts have been explored for the synthesis of liquid biofuels. Chemo-catalysis is mainly metal based, which requires harsh process conditions. Alternatively, biocatalysts are currently being investigated as a result of several advantages such as mild reaction conditions, recyclability, selectivity and biodegradability. In this work, recent biocatalytic technologies for the preparation of liquid biofuels through food waste valorization are discussed thoroughly. Lipases are employed for the synthesis of biodiesel and the upgradation of bio-oil, whereas methane mono-oxygenases could be explored for the production of methanol via the oxidation of methane generated from food wastes. Industrial production of ethanol from food waste using bioconversion technologies is a success story. To date, there has been no specific report on the use of food waste for propanol preparation using enzymes. The ABE process (Acetone–Butanol–Ethanol) (using suitable microorganisms) is used for butanol preparation, where the vacuum stripping system is integrated to remove butanol from the broth and circumvent inhibition. The synthesis of hydrocarbon fuels from fatty acids and triglycerides can be carried out using enzymes, such as carboxylic acid reductase and fatty acid photodecarboxylase (an algal photoenzyme). Both carboxylic acid reductase and fatty acid photodecarboxylase have not yet been applied in the direct valorization of food wastes. Furthermore, limitations of the reported methods, societal and economic aspects and a fresh perspective on the subject, along with important examples, are described.

PHYSICAL FITNESS TRAINING AND REACTION SPEED IN SPORTS TABLE TENNIS PLAYERS

ABSTRACT Introduction: Table tennis is demanding in terms of athletes’ physical fitness and muscular responsiveness. Excellent physical fitness is important to ensure a high technical level. It can also play an essential role in injury prevention. Objective: Explore the correlation between table tennis players’ movements and their displacements. Methods: Volunteer professional competitors underwent a private 16-week quality speed training program. In this experiment, athletes had their speed analyzed before and after training. Mathematical and statistical analyses were performed on the collected data. Some discussions are made to improve the reflex ability of the athletes. Results: The table tennis players’ physical fitness and action response capacity were explored. After physical exercise, the players’ reflex ability improved. There were statistically significant differences in the data (P<0.05). Conclusion: The results show that special training improves athletes’ reaction speed, endurance, strength, coordination, and flexibility. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

Is enzyme immobilization a mature discipline? Some critical considerations to capitalize on the benefits of immobilization

Enzyme immobilization has been developing since the 1960s and although many industrial biocatalytic processes use the technology to improve enzyme performance, still today we are far from full exploitation of the field. One clear reason is that many evaluate immobilization based on only a few experiments that are not always well-designed. In contrast to many other reviews on the subject, here we highlight the pitfalls of using incorrectly designed immobilization protocols and explain why in many cases sub-optimal results are obtained. We also describe solutions to overcome these challenges and come to the conclusion that recent developments in material science, bioprocess engineering and protein science continue to open new opportunities for the future. In this way, enzyme immobilization, far from being a mature discipline, remains as a subject of high interest and where intense research is still necessary to take full advantage of the possibilities.