🔅Biocatalysis is the use of living or biological systems or their parts to speed up chemical reactions.
– Biocatalysis can employ natural or modified enzymes, which are proteins that act as biological catalysts, or whole cells, which contain various enzymes and cofactors.
– Biocatalysis has many advantages over conventional chemical catalysis, such as: high selectivity, mild conditions, environmental friendliness, and biocompatibility.
– Biocatalysis has also been integrated with other technologies, such as: flow chemistry, protein engineering, and artificial intelligence, to enhance its efficiency and versatility.
– Biocatalysis has found numerous applications in various fields, such as: pharmaceuticals, fine chemicals, food and beverages, biofuels, bioremediation, and biosensors.
🔅 Processes involved in Biocatalysis:
– Some examples of biocatalytic processes are:
1). The synthesis of chiral compounds for drugs; such as statins, antibiotics, antivirals, and anticancer agents. Enzymes can catalyze asymmetric reactions that produce enantiomerically pure products with high yields and low waste. For instance, the enzyme ketoreductase can reduce a ketone group to a chiral alcohol group with high enantioselectivity.
2). The production of flavors and fragrances; such as vanillin, limonene, menthol, and lactones. Enzymes can transform natural or synthetic precursors into complex molecules with desirable sensory properties. For example, the enzyme lipase can catalyze the esterification of alcohols and acids to produce fruity or floral esters.
3). The conversion of biomass into biofuels; such as ethanol, biodiesel, and biogas. Enzymes can degrade lignocellulosic materials into fermentable sugars or fatty acids that can be further processed into fuels. For example, the enzyme cellulase can hydrolyze cellulose into glucose that can be fermented by yeast into ethanol.
4). The remediation of environmental pollutants; such as pesticides, heavy metals, dyes, and plastics. Enzymes can degrade or detoxify harmful substances into harmless or useful products. For example, the enzyme laccase can oxidize phenolic compounds and aromatic amines into water-soluble products that can be easily removed.
5). The development of biosensors; for medical diagnostics food quality control, environmental monitoring, and biodefense. Enzymes can act as recognition elements that bind to specific analytes and generate measurable signals. For example, the enzyme glucose oxidase can react with glucose and produce hydrogen peroxide that can be detected by an electrode.
– There are different types of biocatalysis depending on the nature and source of the biocatalyst. Some of the common types of biocatalysis are:
Enzymatic Biocatalysis
– This type of biocatalysis uses isolated or purified enzymes that are free or immobilized on a solid support. Enzymatic biocatalysis offers high specificity and activity but requires optimal conditions and cofactors for the enzyme to function.
Whole-cell Biocatalysis
– This type of biocatalysis uses intact cells or cell extracts that contain multiple enzymes and cofactors. Whole-cell biocatalysis offers high stability and diversity but may suffer from low permeability and productivity.
Artificial Biocatalysis
– This type of biocatalysis uses synthetic or modified enzymes or cells that have been engineered to perform novel or improved reactions. Artificial biocatalysis offers high versatility and adaptability but may face challenges in expression and regulation.
The steps involved in biocatalytic processes vary depending on the type and scale of the application. However, some general steps are:
🔅Selection of the Biocatalyst
– This step involves choosing the appropriate enzyme or cell that can catalyze the desired reaction with high efficiency and selectivity. This may require screening natural sources or designing artificial variants using protein engineering or directed evolution techniques.
🔅 Optimization of the Reaction Conditions
– This step involves adjusting the parameters such as temperature, pH, substrate concentration, cofactor concentration, solvent type, etc., that affect the performance of the biocatalyst. This may require experimental design or computational modeling techniques.
🔅 Scale-up of the Reaction
– This step involves transferring the optimized reaction from laboratory to industrial scale while maintaining the quality and quantity of the product. This may require process engineering or flow chemistry techniques.
🔅 Recovery and Purification of the Product
– This step involves separating the product from the reaction mixture and removing any impurities or by-products. This may require chromatography or extraction techniques.
Biocatalysis is a rapidly growing field that has many important details to consider. Some of these details are:
🔅 The Stability and Reusability of the Biocatalyst
– The biocatalyst should be able to retain its activity and structure over multiple cycles and under harsh conditions. This can be achieved by immobilizing the biocatalyst on a suitable support or modifying its amino acid sequence.
🔅 The Selectivity and Specificity of the Biocatalyst:
The biocatalyst should be able to discriminate between different substrates and products and produce the desired stereochemistry and regiochemistry. This can be achieved by using enzymes with high affinity and catalytic power or engineering the active site or binding pocket of the enzyme.
🔅 The Compatibility and Integration of the Biocatalyst
– The biocatalyst should be able to work well with other biocatalysts or chemical catalysts and form efficient and sustainable reaction networks or cascades. This can be achieved by using compatible solvents and cofactors or designing artificial fusion enzymes or cells.
