Enzymes are biocatalysts that play an important role at all stages of metabolism and biochemical reactions. They are of particular interest and are used as organic catalysts in numerous processes on an industrial scale. This article provides an overview of the enzymes of microorganisms and their classification.
Introduction
Various bioproductors need enzymes with special characteristics for their use in the processing of substrates and raw materials. Microorganism enzymes act as biocatalysts to carry out reactions in biological processes in an economical and environmentally friendly way compared to using chemical catalysts. Their special characteristics are used for commercial interest and industrial applications. Enzymes are very specific, they catalyze about 4000 biochemical reactions. Nobel laureate Emil Fischer suggested that this is because both the enzyme and the substrate have specific complementary geometric shapes that fit exactly together.
Definition
Enzymes are large biological molecules that are responsible for all those important chemical interconversions that are necessary to sustain life. They are highly selective catalysts that can significantly accelerate both the speed and specificity of metabolic reactions, which range from digestion of food to DNA synthesis. From what enzymes are formed in the cells of microorganisms, all metabolic processes occurring in them depend.
History
In 1877, Wilhelm Friedrich Kühne, professor of physiology at the University of Heidelberg, first used the term “enzyme”, which comes from the Latin word fermentum , meaning “leaven”. The production of microorganism enzymes began in ancient Greece. They were used to preserve food and drink.
In 1783, the famous Italian Catholic priest Lazzaro Spallanzani first mentioned the importance of this biomolecule in his work on biogenesis.
In 1812, Gottlieb Sigismund Kirchhoff investigated the process of converting starch into glucose. In his experiment, he highlights the use of enzymes as a catalyst.
In 1833, French chemist Anselm Payen discovered the first enzyme, diastase.
A few decades later, in 1862, when studying the fermentation of sugar to alcohol, Louis Pasteur came to the conclusion that it was catalyzed by the vital force contained in yeast cells.
Biomolecules found in nature have been widely used since ancient times in the manufacture of products such as flax, leather and indigo. All these processes were caused by microorganisms - producers of enzymes.
Value
Enzymes are needed to facilitate chemical reactions. Their role in the life of microorganisms is very important. It consists in providing metabolic processes, respiration, digestion and other types of life. When enzymes function properly, homeostasis persists. Another role of enzymes in microorganisms is the acceleration of metabolism.
Special features
The properties of microorganism enzymes include:
- heat resistance;
- thermophilic nature;
- tolerance to the changing pH range;
- stability of activity when changing temperatures and pH;
- other harsh reaction conditions.
They are divided into thermophilic, acidophilic or alkalophilic. Microorganisms with thermostable enzyme systems reduce the possibility of microbial contamination in long-term large-scale industrial reactions. Microorganism enzymes help in increasing mass transfer and lowering the viscosity of the substrate during the hydrolysis of the feed.
Classification
Due to the wide range of activities based on the nature of their reaction, enzymes are classified according to catalysis:
- Oxidoreductases. Oxidation reactions include the transfer of electrons from one molecule to another. In biological systems, this is the removal of hydrogen from a substrate.
- Transferase. This class of enzymes catalyzes the transfer of groups of atoms from one molecule to another. Aminotransferases or transaminases promote the transfer of an amino group from an amino acid to alpha oxo acid.
- Hydrolases. Catalyze the hydrolysis, the splitting of substrates with water. Reactions include the cleavage of peptide bonds in proteins, glycosidic bonds in carbohydrates, and ester bonds in lipids. As a rule, larger molecules break up into smaller fragments.
- Liases. Catalyze the addition of groups to double bonds or the formation of the latter by removal of the former. For example, pectate lyases cleave glycosidic bonds by beta elimination.
- Isomerase. Catalyze the transfer of groups from one position to another in the same molecule. Change the structure of the substrate, rearranging its atoms.
- Ligase. Combine the molecules together with covalent bonds. Participate in biosynthetic reactions, where new groups of bonds are formed. Such reactions require the input of energy in the form of cofactors.
Application
Fermentation is used in the preparation of many foods. The use of microorganism enzymes in the food industry is a long-standing process. The following types are widely used:
- Amylase. Liquefying starch, improving the quality of bread, lightening fruit juices.
- Glucoamylases. Production of beer and high glucose and fructose syrups.
- Protease. Tenderization of meat, coagulation of milk.
- Lactase. Decreased lactose intolerance in humans, prebiotic nutritional supplements.
- Lipase. Cheddar cheese production.
- Phospholipases. Production of lipolized milk fat.
- Esterasam. Improving the taste and aroma in fruit juice. Deesterification of dietary fiber. Production of short chain esters.
- Cellulase Pet food.
- Glucose oxidase. Improving the shelf life of food.
- Laccases. Removing polyphenols from wine.
- Catalases. Food preservation. Removing hydrogen peroxide from milk prior to cheese production.
- Peroxidase. The development of taste, color and quality of food.
Protease
Proteases derived from microbial systems are of three types: acidic, neutral and alkaline. Alkaline serine proteases are most used in the bio-industry. They have high activity and stability under abnormal conditions of extreme physiological parameters. Alkaline proteases have the property of high stability of enzymatic activity when used in detergents. They have found wide application in the bio-industry:
- production of washing powders;
- food industry;
- skin treatment;
- Pharmaceuticals
- research in molecular biology and peptide synthesis.
Amylase
It is an enzyme of microorganisms that catalyzes the breakdown of starch into sugars. It was discovered and isolated by Anselm Payen in 1833. All amylases are glycoside hydrolases. They are widely used in industry and occupy almost 25% of the enzyme market. Used in industries such as:
- food;
- bakery;
- paper and textile;
- sweeteners and fruit juices;
- glucose and fructose syrups;
- detergents;
- fuel ethanol from starches;
- alcoholic drinks;
- digestive assistance;
- dry cleaning stain remover.
Also used in clinical, medical and analytical chemistry.
Xylanase
Hemicellulose is one of the main constituents of agricultural residues along with cellulose, lignin and pectin. Xylan is its main component. The importance of xylanase has increased significantly due to its biotechnological applications for the production of pentose, purification of fruit juices, improved digestion and bioconversion of lignocellulosic agricultural waste into fuel and chemicals. It has found its application in the food, textile and pulp and paper industries, agricultural waste management, and the production of ethanol and animal feed.
Laccase
Ligninolytic enzymes are applicable in the hydrolysis of lignocellulosic agricultural residues, especially for the degradation of complex and non-pumping constituent lignin. They are very versatile in nature and can be used in a number of industrial processes. The lignolitic enzyme system is used in biobleaching of cellulose, and in other industries, such as stabilization of wine and fruit juices, denim washing, cosmetics and biosensors.
Lipase
It is an enzyme of microorganisms that catalyzes the breakdown and hydrolysis of fats. Lipases are a subclass of esterases. They play a significant role in the digestion, transport and processing of fats. Most lipases are involved in a certain position on the glycerin backbone of the fatty substrate, especially in the small intestine. Some of them are expressed by secreted pathogens during an infectious disease. Lipases are considered the main group of biotechnologically valuable enzymes, mainly due to the universality of their applied properties and the ease of mass production.
Lipase
These enzymes are involved in a variety of biological processes, ranging from the routine metabolism of triglycerides in the diet to signaling and cell inflammation. Some lipase activities are limited to certain compartments within cells, while others work in extracellular spaces:
- Pancreatic lipases are secreted into the extracellular spaces, where they serve to process food lipids into simpler forms that are carried throughout the body.
- Facilitate the absorption of nutrients from the environment.
- Increased lipase activity replaces traditional catalysts in biodiesel processing.
- Used in areas such as baking, laundry detergents, as biocatalysts.
- In the textile industry it is used to increase the absorbency of fabric and evenness during dyeing.
- To modify the food taste by synthesizing esters of short chain fatty acids and alcohols.
- The presence or high level of lipases may indicate a specific infection or disease and can be used as a diagnostic tool.
- They have a bactericidal effect. Can be used in the treatment of malignant tumors.
- They are of great commercial importance in cosmetics and pharmaceuticals (skin care products, hair curlers).