Cross-linked enzyme aggregate
Encyclopedia
In biochemistry
, a cross-linked enzyme aggregate is an immobilized enzyme
prepared via crosslinking. They can be used as stereoselective industrial biocatalysts.
s. They are natural catalysts and are ubiquitous, in plants, animals and microorganism
s where they catalyze processes that are vital to living organisms. They are intimately involved in numerous biotechnological processes, such as cheese making, beer brewing and winemaking, that date back to the dawn of civilization. Recent advances in biotechnology
, particularly in genetic and protein engineering
, and genetics
have provided the basis for the efficient development of enzyme
s with improved properties for established applications and novel, tailor-made enzyme
s for completely new applications where enzymes were not previously used.
Today, enzymes are widely applied in many different industries and the number of applications continues to increase. Examples include food
(baking, dairy products, starch conversion) and beverage (beer, wine, fruit and vegetable juices) processing, animal feed
, textile
s, pulp
and paper
, detergent
s, biosensor
s, cosmetics
, health care
and nutrition
, waste water treatment
, pharmaceutical and chemical manufacture and, more recently, biofuel
s such as biodiesel
. The main driver for the widespread application of enzymes is their small environmental footprint.
Many traditional chemical conversions used in various industries suffer from inherent drawbacks from both an economic and environmental viewpoint. Non-specific reactions can afford low product yields, copious amounts of waste and impure products. The need for elevated temperatures and pressures leads to high energy consumption and high capital investment costs. Disposal of unwanted by-products may be difficult and/or expensive and hazardous solvents may be required. In stark contrast, enzymatic reactions are performed under mild conditions of temperature and pressure, in water as solvent, and exhibit very high rates and are often highly specific. Moreover, they are produced from renewable raw materials and are biodegradable. In addition, the mild operating conditions of enzymatic processes mean that they can be performed in relatively simple equipment and are easy to control. In short, they reduce the environmental footprint of manufacturing by reducing the consumption of energy and chemicals and concomitant generation of waste.
In the production of fine chemicals
, flavor
s and fragrance
s, agrochemicals and pharmaceuticals an important benefit of enzyme
s is the high degree of chemoselectivity
, regioselectivity
and enantioselectivity which they exhibit. Particularly, their ability to catalyze the formation of products in high enantiopurity, by an exquisite stereochemical control, is of the utmost importance in these industries.
Notwithstanding all these desirable characteristic features of enzymes their widespread industrial application is often hampered by their lack of long term operational stability and shelf-storage life, and their cumbersome recovery and re-use. These drawbacks can generally be overcome by immobilization of the enzyme and a major challenge in industrial biocatalysis is the development of stable, robust and preferably insoluble biocatalysts.
There are several reasons for immobilizing an enzyme. In addition to more convenient handling of the enzyme, it provides for its facile separation from the product, thereby minimizing or eliminating protein contamination of the product. Immobilization also facilitates the efficient recovery and re-use of costly enzymes, in many applications a conditio sine qua non for economic viability, and enables their use in continuous, fixed-bed operation. A further benefit is often enhanced stability, under both storage and operational conditions, e.g. towards denaturation
by heat or organic solvents or by autolysis. Enzymes are rather delicate molecules that can easily lose their unique three dimensional structure, essential for their activity, by denaturation
(unfolding). Improved enzyme performance via enhanced stability, over a broad pH and temperature range as well as tolerance towards organic solvents, coupled with repeated re-use is reflected in higher catalyst productivities (kg product/kg enzyme) which, in turn, determine the enzyme costs per kg product.
Basically, three traditional methods of enzyme immobilization can be distinguished: binding to a support(carrier), entrapment (encapsulation) and cross-linking. Support binding can be physical, ionic
, or covalent in nature. However, physical bonding is generally too weak to keep the enzyme fixed to the carrier under industrial conditions of high reactant and product concentrations and high ionic strength. The support can be a synthetic resin
, a biopolymer
or an inorganic polymer
such as (mesoporous) silica or a zeolite
. Entrapment involves inclusion of an enzyme in a polymer network (gel lattice) such as an organic polymer or a silica sol-gel, or a membrane
device such as a hollow fiber or a microcapsule. Entrapment requires the synthesis of the polymeric network in the presence of the enzyme. The third category involves cross-linking of enzyme aggregates or crystals, using a bifunctional reagent, to prepare carrier-free macroparticles.
The use of a carrier inevitably leads to ‘dilution of activity’, owing to the introduction of a large portion of non-catalytic ballast, ranging from 90% to >99%, which results in lower space-time yields and productivities. Moreover, immobilization of an enzyme on a carrier often leads to a substantial loss of activity, especially at high enzyme loadings. Consequently, there is an increasing interest in carrier-free immobilized enzymes, such as cross-linked enzyme crystals (CLECs) and cross-linked enzyme aggregates (CLEAs) that offer the advantages of highly concentrated enzyme activity combined with high stability and low production costs owing to the exclusion of an additional (expensive) carrier.
by heat, organic solvents and proteolysis
than the corresponding soluble enzyme or lyophilized (freeze-dried) powder. CLECs are robust, highly active immobilized enzymes of controllable particle size, varying from 1 to 100 micrometer. Their operational stability and ease of recycling, coupled with their high catalyst and volumetric productivities, renders them ideally suited for industrial biotransformations.
However, CLECs have an inherent disadvantage: enzyme crystallization
is a laborious procedure requiring enzyme of high purity, which translates to prohibitively high costs. The more recently developed cross-linked enzyme aggregates (CLEAs) , on the other hand, are produced by simple precipitation of the enzyme from aqueous solution, as physical aggregates of protein molecules, by the addition of salts, or water miscible organic solvents or non-ionic polymers. The physical aggregates are held together by non-covalent bonding without perturbation of their tertiary structure, that is without denaturation. Subsequent cross-linking of these physical aggregates renders them permanently insoluble while maintaining their pre-organized superstructure, and, hence their catalytic activity. This discovery led to the development of a new family of immobilized enzymes: cross-linked enzyme aggregates (CLEAs). Since precipitation from an aqueous medium, by addition of ammonium sulfate
or polyethylene glycol
, is often used to purify enzymes, the CLEA methodology essentially combines purification and immobilization into a single unit operation that does not require a highly pure enzyme. It could be used, for example, for the direct isolation of an enzyme, in a purified and immobilized form suitable for performing biotransformations, from a crude fermentation
broth.
CLEAs are very attractive biocatalysts, owing to their facile, inexpensive and effective production method. They can readily be reused and exhibit improved stability and performance. The methodology is applicable to essentially any enzyme, including cofactor
dependent oxidoreductases. Application to penicillin acylase used in antibiotic
synthesis showed large improvements over other type of biocatalysts.
The potential applications of CLEAs are numerous and include:
1. Synthesis of pharmaceuticals, flavor
s and fragrance
s, agrochemicals, nutraceutical
s, fine chemicals
, bulk monomers and biofuel
s.
2. Animal feed
, e.g. phytase
for utilization of organically bound phosphate
by pigs and poultry.
3. Food and beverage processing, e.g. lipases in cheese manufacture and laccase
in wine clarification.
4. Cosmetics
, e.g. in skin care products
5. Oils and fat
s processing, e.g. in biolubricants, bioemulsifiers, bioemollients.
6. Carbohydrate
processing, e.g. laccase
in carbohydrate oxidations.
7. Pulp and paper, e.g. in pulp bleaching.
8. Detergents, e.g. proteases, amylases and lipases for removal of protein, carbohydrate and fat stains.
9. Waste water treatment, e.g. for removal of phenols
, dyes, and endocrine disrupters.
10. Biosensors/diagnostics, e.g. glucose oxidase
and cholesterol oxidase biosensors.
11. Delivery of proteins as therapeutic agents or nutritional/digestive supplements e.g. beta-galactosidase
for digestive hydrolysis of lactose
in dairy products to alleviate the symptoms of lactose intolerance
.
Biochemistry
Biochemistry, sometimes called biological chemistry, is the study of chemical processes in living organisms, including, but not limited to, living matter. Biochemistry governs all living organisms and living processes...
, a cross-linked enzyme aggregate is an immobilized enzyme
Immobilized enzyme
An immobilized enzyme is an enzyme that is attached to an inert, insoluble material such as calcium alginate . This can provide increased resistance to changes in conditions such as pH or temperature...
prepared via crosslinking. They can be used as stereoselective industrial biocatalysts.
Background
Enzymes are proteins that catalyze (i.e. accelerate) chemical reactionChemical reaction
A chemical reaction is a process that leads to the transformation of one set of chemical substances to another. Chemical reactions can be either spontaneous, requiring no input of energy, or non-spontaneous, typically following the input of some type of energy, such as heat, light or electricity...
s. They are natural catalysts and are ubiquitous, in plants, animals and microorganism
Microorganism
A microorganism or microbe is a microscopic organism that comprises either a single cell , cell clusters, or no cell at all...
s where they catalyze processes that are vital to living organisms. They are intimately involved in numerous biotechnological processes, such as cheese making, beer brewing and winemaking, that date back to the dawn of civilization. Recent advances in biotechnology
Biotechnology
Biotechnology is a field of applied biology that involves the use of living organisms and bioprocesses in engineering, technology, medicine and other fields requiring bioproducts. Biotechnology also utilizes these products for manufacturing purpose...
, particularly in genetic and protein engineering
Protein engineering
Protein engineering is the process of developing useful or valuable proteins. It is a young discipline, with much research taking place into the understanding of protein folding and recognition for protein design principles....
, and genetics
Genetics
Genetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....
have provided the basis for the efficient development of enzyme
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...
s with improved properties for established applications and novel, tailor-made enzyme
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...
s for completely new applications where enzymes were not previously used.
Today, enzymes are widely applied in many different industries and the number of applications continues to increase. Examples include food
Food
Food is any substance consumed to provide nutritional support for the body. It is usually of plant or animal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals...
(baking, dairy products, starch conversion) and beverage (beer, wine, fruit and vegetable juices) processing, animal feed
Compound feed
Compound feeds are feedstuffs that are blended from various raw materials and additives. These blends are formulated according to the specific requirements of the target animal...
, textile
Textile
A textile or cloth is a flexible woven material consisting of a network of natural or artificial fibres often referred to as thread or yarn. Yarn is produced by spinning raw fibres of wool, flax, cotton, or other material to produce long strands...
s, pulp
Wood pulp
Pulp is a lignocellulosic fibrous material prepared by chemically or mechanically separating cellulose fibres from wood, fibre crops or waste paper. Wood pulp is the most common raw material in papermaking.-History:...
and paper
Paper
Paper is a thin material mainly used for writing upon, printing upon, drawing or for packaging. It is produced by pressing together moist fibers, typically cellulose pulp derived from wood, rags or grasses, and drying them into flexible sheets....
, detergent
Detergent
A detergent is a surfactant or a mixture of surfactants with "cleaning properties in dilute solutions." In common usage, "detergent" refers to alkylbenzenesulfonates, a family of compounds that are similar to soap but are less affected by hard water...
s, biosensor
Biosensor
A biosensor is an analytical device for the detection of an analyte that combines a biological component with a physicochemical detector component.It consists of 3 parts:* the sensitive biological element A biosensor is an analytical device for the detection of an analyte that combines a biological...
s, cosmetics
Cosmetics
Cosmetics are substances used to enhance the appearance or odor of the human body. Cosmetics include skin-care creams, lotions, powders, perfumes, lipsticks, fingernail and toe nail polish, eye and facial makeup, towelettes, permanent waves, colored contact lenses, hair colors, hair sprays and...
, health care
Health care
Health care is the diagnosis, treatment, and prevention of disease, illness, injury, and other physical and mental impairments in humans. Health care is delivered by practitioners in medicine, chiropractic, dentistry, nursing, pharmacy, allied health, and other care providers...
and nutrition
Nutrition
Nutrition is the provision, to cells and organisms, of the materials necessary to support life. Many common health problems can be prevented or alleviated with a healthy diet....
, waste water treatment
Sewage treatment
Sewage treatment, or domestic wastewater treatment, is the process of removing contaminants from wastewater and household sewage, both runoff and domestic. It includes physical, chemical, and biological processes to remove physical, chemical and biological contaminants...
, pharmaceutical and chemical manufacture and, more recently, biofuel
Biofuel
Biofuel is a type of fuel whose energy is derived from biological carbon fixation. Biofuels include fuels derived from biomass conversion, as well as solid biomass, liquid fuels and various biogases...
s such as biodiesel
Biodiesel
Biodiesel refers to a vegetable oil- or animal fat-based diesel fuel consisting of long-chain alkyl esters. Biodiesel is typically made by chemically reacting lipids with an alcohol....
. The main driver for the widespread application of enzymes is their small environmental footprint.
Many traditional chemical conversions used in various industries suffer from inherent drawbacks from both an economic and environmental viewpoint. Non-specific reactions can afford low product yields, copious amounts of waste and impure products. The need for elevated temperatures and pressures leads to high energy consumption and high capital investment costs. Disposal of unwanted by-products may be difficult and/or expensive and hazardous solvents may be required. In stark contrast, enzymatic reactions are performed under mild conditions of temperature and pressure, in water as solvent, and exhibit very high rates and are often highly specific. Moreover, they are produced from renewable raw materials and are biodegradable. In addition, the mild operating conditions of enzymatic processes mean that they can be performed in relatively simple equipment and are easy to control. In short, they reduce the environmental footprint of manufacturing by reducing the consumption of energy and chemicals and concomitant generation of waste.
In the production of fine chemicals
Fine chemicals
Fine chemicals are pure, single chemical substances that are commercially produced with chemical reactions for highly specialized applications. Fine chemicals produced can be categorized into active pharmaceutical ingredients and their intermediates, biocides, and specialty chemicals for technical...
, flavor
Flavor
Flavor or flavour is the sensory impression of a food or other substance, and is determined mainly by the chemical senses of taste and smell. The "trigeminal senses", which detect chemical irritants in the mouth and throat as well as temperature and texture, are also very important to the overall...
s and fragrance
Aroma compound
An aroma compound, also known as odorant, aroma, fragrance or flavor, is a chemical compound that has a smell or odor...
s, agrochemicals and pharmaceuticals an important benefit of enzyme
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...
s is the high degree of chemoselectivity
Chemoselectivity
Chemical reactions are defined usually in small contexts , such generalizations are a matter of utility. The preferential outcome of one instance of a generalized reaction over a set of other plausible reactions, is defined as chemoselectivity...
, regioselectivity
Regioselectivity
In chemistry, regioselectivity is the preference of one direction of chemical bond making or breaking over all other possible directions. It can often apply to which of many possible positions a reagent will affect, such as which proton a strong base will abstract from an organic molecule, or where...
and enantioselectivity which they exhibit. Particularly, their ability to catalyze the formation of products in high enantiopurity, by an exquisite stereochemical control, is of the utmost importance in these industries.
Notwithstanding all these desirable characteristic features of enzymes their widespread industrial application is often hampered by their lack of long term operational stability and shelf-storage life, and their cumbersome recovery and re-use. These drawbacks can generally be overcome by immobilization of the enzyme and a major challenge in industrial biocatalysis is the development of stable, robust and preferably insoluble biocatalysts.
Immobilisation
- See Immobilized enzymeImmobilized enzymeAn immobilized enzyme is an enzyme that is attached to an inert, insoluble material such as calcium alginate . This can provide increased resistance to changes in conditions such as pH or temperature...
for more information.
There are several reasons for immobilizing an enzyme. In addition to more convenient handling of the enzyme, it provides for its facile separation from the product, thereby minimizing or eliminating protein contamination of the product. Immobilization also facilitates the efficient recovery and re-use of costly enzymes, in many applications a conditio sine qua non for economic viability, and enables their use in continuous, fixed-bed operation. A further benefit is often enhanced stability, under both storage and operational conditions, e.g. towards denaturation
Denaturation (biochemistry)
Denaturation is a process in which proteins or nucleic acids lose their tertiary structure and secondary structure by application of some external stress or compound, such as a strong acid or base, a concentrated inorganic salt, an organic solvent , or heat...
by heat or organic solvents or by autolysis. Enzymes are rather delicate molecules that can easily lose their unique three dimensional structure, essential for their activity, by denaturation
Denaturation (biochemistry)
Denaturation is a process in which proteins or nucleic acids lose their tertiary structure and secondary structure by application of some external stress or compound, such as a strong acid or base, a concentrated inorganic salt, an organic solvent , or heat...
(unfolding). Improved enzyme performance via enhanced stability, over a broad pH and temperature range as well as tolerance towards organic solvents, coupled with repeated re-use is reflected in higher catalyst productivities (kg product/kg enzyme) which, in turn, determine the enzyme costs per kg product.
Basically, three traditional methods of enzyme immobilization can be distinguished: binding to a support(carrier), entrapment (encapsulation) and cross-linking. Support binding can be physical, ionic
Ionic bond
An ionic bond is a type of chemical bond formed through an electrostatic attraction between two oppositely charged ions. Ionic bonds are formed between a cation, which is usually a metal, and an anion, which is usually a nonmetal. Pure ionic bonding cannot exist: all ionic compounds have some...
, or covalent in nature. However, physical bonding is generally too weak to keep the enzyme fixed to the carrier under industrial conditions of high reactant and product concentrations and high ionic strength. The support can be a synthetic resin
Resin
Resin in the most specific use of the term is a hydrocarbon secretion of many plants, particularly coniferous trees. Resins are valued for their chemical properties and associated uses, such as the production of varnishes, adhesives, and food glazing agents; as an important source of raw materials...
, a biopolymer
Biopolymer
Biopolymers are polymers produced by living organisms. Since they are polymers, Biopolymers contain monomeric units that are covalently bonded to form larger structures. There are three main classes of biopolymers based on the differing monomeric units used and the structure of the biopolymer formed...
or an inorganic polymer
Polymer
A polymer is a large molecule composed of repeating structural units. These subunits are typically connected by covalent chemical bonds...
such as (mesoporous) silica or a zeolite
Zeolite
Zeolites are microporous, aluminosilicate minerals commonly used as commercial adsorbents. The term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt, who observed that upon rapidly heating the material stilbite, it produced large amounts of steam from water that...
. Entrapment involves inclusion of an enzyme in a polymer network (gel lattice) such as an organic polymer or a silica sol-gel, or a membrane
Membrane (selective barrier)
A membrane is a layer of material which serves as a selective barrier between two phases and remains impermeable to specific particles, molecules, or substances when exposed to the action of a driving force...
device such as a hollow fiber or a microcapsule. Entrapment requires the synthesis of the polymeric network in the presence of the enzyme. The third category involves cross-linking of enzyme aggregates or crystals, using a bifunctional reagent, to prepare carrier-free macroparticles.
The use of a carrier inevitably leads to ‘dilution of activity’, owing to the introduction of a large portion of non-catalytic ballast, ranging from 90% to >99%, which results in lower space-time yields and productivities. Moreover, immobilization of an enzyme on a carrier often leads to a substantial loss of activity, especially at high enzyme loadings. Consequently, there is an increasing interest in carrier-free immobilized enzymes, such as cross-linked enzyme crystals (CLECs) and cross-linked enzyme aggregates (CLEAs) that offer the advantages of highly concentrated enzyme activity combined with high stability and low production costs owing to the exclusion of an additional (expensive) carrier.
Cross-Linked Enzyme Aggregates (CLEAs)
The use of cross-linked enzyme crystals (CLECs) as industrial biocatalysts was pioneered by Altus Biologics in the 1990s. CLECs proved to be significantly more stable to denaturationDenaturation (biochemistry)
Denaturation is a process in which proteins or nucleic acids lose their tertiary structure and secondary structure by application of some external stress or compound, such as a strong acid or base, a concentrated inorganic salt, an organic solvent , or heat...
by heat, organic solvents and proteolysis
Proteolysis
Proteolysis is the directed degradation of proteins by cellular enzymes called proteases or by intramolecular digestion.-Purposes:Proteolysis is used by the cell for several purposes...
than the corresponding soluble enzyme or lyophilized (freeze-dried) powder. CLECs are robust, highly active immobilized enzymes of controllable particle size, varying from 1 to 100 micrometer. Their operational stability and ease of recycling, coupled with their high catalyst and volumetric productivities, renders them ideally suited for industrial biotransformations.
However, CLECs have an inherent disadvantage: enzyme crystallization
Crystallization
Crystallization is the process of formation of solid crystals precipitating from a solution, melt or more rarely deposited directly from a gas. Crystallization is also a chemical solid–liquid separation technique, in which mass transfer of a solute from the liquid solution to a pure solid...
is a laborious procedure requiring enzyme of high purity, which translates to prohibitively high costs. The more recently developed cross-linked enzyme aggregates (CLEAs) , on the other hand, are produced by simple precipitation of the enzyme from aqueous solution, as physical aggregates of protein molecules, by the addition of salts, or water miscible organic solvents or non-ionic polymers. The physical aggregates are held together by non-covalent bonding without perturbation of their tertiary structure, that is without denaturation. Subsequent cross-linking of these physical aggregates renders them permanently insoluble while maintaining their pre-organized superstructure, and, hence their catalytic activity. This discovery led to the development of a new family of immobilized enzymes: cross-linked enzyme aggregates (CLEAs). Since precipitation from an aqueous medium, by addition of ammonium sulfate
Ammonium sulfate
Ammonium sulfate , 2SO4, is an inorganic salt with a number of commercial uses. The most common use is as a soil fertilizer. It contains 21% nitrogen as ammonium cations, and 24% sulfur as sulfate anions...
or polyethylene glycol
Polyethylene glycol
Polyethylene glycol is a polyether compound with many applications from industrial manufacturing to medicine. It has also been known as polyethylene oxide or polyoxyethylene , depending on its molecular weight, and under the tradename Carbowax.-Available forms:PEG, PEO, or POE refers to an...
, is often used to purify enzymes, the CLEA methodology essentially combines purification and immobilization into a single unit operation that does not require a highly pure enzyme. It could be used, for example, for the direct isolation of an enzyme, in a purified and immobilized form suitable for performing biotransformations, from a crude fermentation
Fermentation (biochemistry)
Fermentation is the process of extracting energy from the oxidation of organic compounds, such as carbohydrates, using an endogenous electron acceptor, which is usually an organic compound. In contrast, respiration is where electrons are donated to an exogenous electron acceptor, such as oxygen,...
broth.
CLEAs are very attractive biocatalysts, owing to their facile, inexpensive and effective production method. They can readily be reused and exhibit improved stability and performance. The methodology is applicable to essentially any enzyme, including cofactor
Cofactor (biochemistry)
A cofactor is a non-protein chemical compound that is bound to a protein and is required for the protein's biological activity. These proteins are commonly enzymes, and cofactors can be considered "helper molecules" that assist in biochemical transformations....
dependent oxidoreductases. Application to penicillin acylase used in antibiotic
Antibiotic
An antibacterial is a compound or substance that kills or slows down the growth of bacteria.The term is often used synonymously with the term antibiotic; today, however, with increased knowledge of the causative agents of various infectious diseases, antibiotic has come to denote a broader range of...
synthesis showed large improvements over other type of biocatalysts.
The potential applications of CLEAs are numerous and include:
1. Synthesis of pharmaceuticals, flavor
Flavor
Flavor or flavour is the sensory impression of a food or other substance, and is determined mainly by the chemical senses of taste and smell. The "trigeminal senses", which detect chemical irritants in the mouth and throat as well as temperature and texture, are also very important to the overall...
s and fragrance
Aroma compound
An aroma compound, also known as odorant, aroma, fragrance or flavor, is a chemical compound that has a smell or odor...
s, agrochemicals, nutraceutical
Nutraceutical
Nutraceutical, a portmanteau of the words “nutrition” and “pharmaceutical”, is a food or food product that reportedly provides health and medical benefits, including the prevention and treatment of disease. Health Canada defines the term as "a product isolated or purified from foods that is...
s, fine chemicals
Fine chemicals
Fine chemicals are pure, single chemical substances that are commercially produced with chemical reactions for highly specialized applications. Fine chemicals produced can be categorized into active pharmaceutical ingredients and their intermediates, biocides, and specialty chemicals for technical...
, bulk monomers and biofuel
Biofuel
Biofuel is a type of fuel whose energy is derived from biological carbon fixation. Biofuels include fuels derived from biomass conversion, as well as solid biomass, liquid fuels and various biogases...
s.
2. Animal feed
Compound feed
Compound feeds are feedstuffs that are blended from various raw materials and additives. These blends are formulated according to the specific requirements of the target animal...
, e.g. phytase
Phytase
A phytase is any type of phosphatase enzyme that catalyzes the hydrolysis of phytic acid --an undigestible, organic form of phosphorus that is found in grains and oil seeds-- and releases a usable form of inorganic phosphorus...
for utilization of organically bound phosphate
Phosphate
A phosphate, an inorganic chemical, is a salt of phosphoric acid. In organic chemistry, a phosphate, or organophosphate, is an ester of phosphoric acid. Organic phosphates are important in biochemistry and biogeochemistry or ecology. Inorganic phosphates are mined to obtain phosphorus for use in...
by pigs and poultry.
3. Food and beverage processing, e.g. lipases in cheese manufacture and laccase
Laccase
Laccases are copper-containing oxidase enzymes that are found in many plants, fungi, and microorganisms. The copper is bound in several sites; Type 1, Type 2, and/or Type 3. The ensemble of types 2 and 3 copper is called a trinuclear cluster . Type 1 copper is available to action of solvents,...
in wine clarification.
4. Cosmetics
Cosmetics
Cosmetics are substances used to enhance the appearance or odor of the human body. Cosmetics include skin-care creams, lotions, powders, perfumes, lipsticks, fingernail and toe nail polish, eye and facial makeup, towelettes, permanent waves, colored contact lenses, hair colors, hair sprays and...
, e.g. in skin care products
5. Oils and fat
Fat
Fats consist of a wide group of compounds that are generally soluble in organic solvents and generally insoluble in water. Chemically, fats are triglycerides, triesters of glycerol and any of several fatty acids. Fats may be either solid or liquid at room temperature, depending on their structure...
s processing, e.g. in biolubricants, bioemulsifiers, bioemollients.
6. Carbohydrate
Carbohydrate
A carbohydrate is an organic compound with the empirical formula ; that is, consists only of carbon, hydrogen, and oxygen, with a hydrogen:oxygen atom ratio of 2:1 . However, there are exceptions to this. One common example would be deoxyribose, a component of DNA, which has the empirical...
processing, e.g. laccase
Laccase
Laccases are copper-containing oxidase enzymes that are found in many plants, fungi, and microorganisms. The copper is bound in several sites; Type 1, Type 2, and/or Type 3. The ensemble of types 2 and 3 copper is called a trinuclear cluster . Type 1 copper is available to action of solvents,...
in carbohydrate oxidations.
7. Pulp and paper, e.g. in pulp bleaching.
8. Detergents, e.g. proteases, amylases and lipases for removal of protein, carbohydrate and fat stains.
9. Waste water treatment, e.g. for removal of phenols
Phenols
In organic chemistry, phenols, sometimes called phenolics, are a class of chemical compounds consisting of a hydroxyl group bonded directly to an aromatic hydrocarbon group...
, dyes, and endocrine disrupters.
10. Biosensors/diagnostics, e.g. glucose oxidase
Glucose oxidase
The glucose oxidase enzyme is an oxido-reductase that catalyses the oxidation of glucose to hydrogen peroxide and D-glucono-δ-lactone. In cells, it aids in breaking the sugar down into its metabolites....
and cholesterol oxidase biosensors.
11. Delivery of proteins as therapeutic agents or nutritional/digestive supplements e.g. beta-galactosidase
Beta-galactosidase
β-galactosidase, also called beta-gal or β-gal, is a hydrolase enzyme that catalyzes the hydrolysis of β-galactosides into monosaccharides. Substrates of different β-galactosidases include ganglioside GM1, lactosylceramides, lactose, and various glycoproteins...
for digestive hydrolysis of lactose
Lactose
Lactose is a disaccharide sugar that is found most notably in milk and is formed from galactose and glucose. Lactose makes up around 2~8% of milk , although the amount varies among species and individuals. It is extracted from sweet or sour whey. The name comes from or , the Latin word for milk,...
in dairy products to alleviate the symptoms of lactose intolerance
Lactose intolerance
Lactose intolerance, also called lactase deficiency or hypolactasia, is the inability to digest and metabolize lactose, a sugar found in milk...
.