Comparison of Covalent and Noncovalent Immobilization of Malatya Apricot Pectinesterase (Prunus armeniacaL.)

A Review on Flexible Electrochemical Biosensors to Monitor Alcohol in Sweat

The continued focus on improving the quality of human life has encouraged the development of increasingly efficient, durable, and cost-effective products in healthcare. Over the last decade, there has been substantial development in the field of technical and interactive textiles that combine expertise in electronics, biology, chemistry, and physics. Most recently, the creation of textile biosensors capable of quantifying biometric data in biological fluids is being studied, to detect a specific disease or the physical condition of an individual. The ultimate goal is to provide access to medical diagnosis anytime and anywhere. Presently, alcohol is considered the most commonly used addictive substance worldwide, being one of the main causes of death in road accidents. Thus, it is important to think of solutions capable of minimizing this public health problem. Alcohol biosensors constitute an excellent tool to aid at improving road safety. Hence, this review explores concepts about alcohol biomarkers, the composition of human sweat and the correlation between alcohol and blood. Different components and requirements of a biosensor are reviewed, along with the electrochemical techniques to evaluate its performance, in addition to construction techniques of textile-based biosensors. Special attention is given to the determination of biomarkers that must be low cost and fast, so the use of biomimetic materials to recognize and detect the target analyte is turning into an attractive option to improve electrochemical behavior.

Enzyme Immobilization and Co-Immobilization: Main Framework, Advances and Some Applications

Enzymes are outstanding (bio)catalysts, not solely on account of their ability to increase reaction rates by up to several orders of magnitude but also for the high degree of substrate specificity, regiospecificity and stereospecificity. The use and development of enzymes as robust biocatalysts is one of the main challenges in biotechnology. However, despite the high specificities and turnover of enzymes, there are also drawbacks. At the industrial level, these drawbacks are typically overcome by resorting to immobilized enzymes to enhance stability. Immobilization of biocatalysts allows their reuse, increases stability, facilitates process control, eases product recovery, and enhances product yield and quality. This is especially important for expensive enzymes, for those obtained in low fermentation yield and with relatively low activity. This review provides an integrated perspective on (multi)enzyme immobilization that abridges a critical evaluation of immobilization methods and carriers, biocatalyst metrics, impact of key carrier features on biocatalyst performance, trends towards miniaturization and detailed illustrative examples that are representative of biocatalytic applications promoting sustainability.

Recent developments in l-glutaminase production and applications - An overview

l-glutaminases is an important industrial enzyme which finds potential applications in different sectors ranging from therapeutic to food industry. It is widely distributed in bacteria, actinomycetes, yeast and fungi. l-Glutaminases are mostly produced by Bacillus and Pseudomonas sp. and few reports were available with fungal, actinomycete and yeast system. Modern biotechnological tools help in the improved production as well as with tailor made properties for specific applications. Most of the genetic engineering studies were carried out for the production of l-glutaminase with improved thermo-tolerance and salt tolerance. Considering the potential of in vitro applications of l-glutaminase, extracellular enzymes are important and most microbes produce this enzyme intracellularly. Several research and developmental activities are going on for the extracellular production of l-glutaminase. This review discusses recent trends and developments and applications of l-glutaminases.

Extraction and characterization of pectin methylesterase from Alyanak apricot (Prunus armeniaca L)

This study was carried out to determine some of the biochemical properties of pectin methylesterase (PME) from Alyanak apricot which is an important variety grown in Malatya region of Turkey. The enzyme had high activity in a pH range of 7.0-8.0 with the maximal activity occurring at pH 7.5. However, the enzyme activity at high and low pH values was very low. The optimum temperature for maximal PME activity was found to be 60 °C. The activity of PME has been enhanced by NaCl, particularly at 0.15 M. Km and Vmax values for Alyanak apricot PME using apple pectin as substrate were found to be 1.69 mg/mL (r(2) = 0.992) and 3.41 units/mL, respectively. The enzyme was stable at 30-45 °C/10 min whereas it lost nearly all of its activity at 80 °C/10 min. Ea and Z values were found to be 206.1 kJ/mol (r(2) = 0.993) and 10.62 °C (r(2) = 0.992), respectively.

Immobilization of glutaminase enzyme from Hypocria jecorina on polyacrylic acid: preparation and biochemical characterization

L-glutaminase enzyme produced from Hypocrea jecorina pure culture and polyacrylic acid (PAA) in the presence (Cu2+) ions were composed the ternary complex at pH 7. The properties of free and immobilized enzyme were defined. The effect of various factors such as pH, temperature, heat, and storage stability on immobilized enzyme were investigated. The properties of immobilized enzyme were investigated and compared to those of free enzyme. Optimum pH and temperature of both enzyme were determined to be 8.0 and 50°C, respectively. Kinetic parameters of the immobilized enzyme (Km and Vmax values) were also determined as 0.38 mM of the Km and 10.9 U/L of the Vmax. No drastic change was observed in the Km and Vmax values. Thermal and storage stability experiments were carried out. The thermal stability studies indicated that the immobilization process tends to stabilize the enzyme.