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Rajani prabhuMI-1414Msc part 1Microbiology.Industrially important fungal enzyme: PROTEINASE Recent years have witnessed a phenomenal increase in the use of enzymes as industrial catalysts. Proteases (EC 3:4, 11-19, 20-24, 99) (synonymous as peptidase or pro- teinase) constitute a very large and complex group of enzymes, widely utilized in most of industries. They differ in properties such as substrate specificity, active site and catalytic mechanism, pH and temperature optima, and stability profiles. The main sources of the enzymes were from animals (e.g. calf stomach), plants (e.g. pineapple, fig, and papaya), microbes (e.g. Bacillus spp., Pseudomonas spp.) etc. But the production of enzymes from plant and animal sources is limited due to climatic reasons and ethical issues, respectively. Microbial sources have occupied an invincible domain in the production of all the threeacidic, neutral, and alkalinemajor types of proteases. classification On the basis of their site of action on protein substrates, proteases are broadly classified as endo- or exo-enzymes. Proteases are also classified into different clans and families depending on their amino acid sequences and evolutionary relationships. Based on the pH optima, they are referred to as acidic, neutral, or alkaline proteases. They are further categorized as serine proteases, aspartic proteases,glutamic acid proteses,threonine proteases cysteine proteases or met- allo proteasesdepending on their catalytic mechanism (Table 1).

Table 1. General classification of proteases with their enzyme commission (EC) code, coupled with specific mechanism of action of each subgroup. Protease EC code MechanismExopeptidases 3, 4, 11-19 cleave the peptide bond proximal to the amino or carboxy termini of the substrate Aminopeptidases 3, 4, 11 Those acting at a free N-terminus liberate a single amino acid residue Dipeptidases 3, 4, 13 Exopeptidases specific for dipeptides Dipeptidyl peptidase 3, 4, 14 Release of an N-terminal dipeptide from a polypeptide Tripeptidyl peptidase 3, 4, 14 Release of an N-terminal tripeptide from a polypeptide Peptidyldipeptidase 3, 4, 15 Release of free C-terminus liberate a dipeptide Carboxypeptidase 3, 4, 16-18 Release of a single residue C-terminal from a polypeptide Serine type protease 3, 4, 16 Carboxypeptidase have an active centre serine involved in the catalytic process Metalloprotease 3, 4, 17 Carboxypeptidase use a metal ion in the catalytic mechanism Cysteine type protease 3, 4, 18 Carboxypeptidase have a cysteine in the active centre Omega peptidases 3, 4, 19 Remove terminal residues that are linked by isopeptide bonds Endopeptidases 3, 4, 21-24 Cleave internal bonds in polypeptide chains Serine protease 3, 4, 21 Endopeptidases have an active centre serine involved in the catalytic process Cysteine protease 3, 4, 22 Possesses a cysteine in the active centre Aspartic protease 3, 4, 23 An aspartic acid residue for their catalytic activity Metalloprotease 3, 4, 24 Use a metal ion (often, but not always, Zn2+) in the catalytic mechanism Endopeptidases of 3, 4, 99 Acting on peptide bonds unknown catalytic mechanism sourcesAnimal Proteases: The most familiar proteases of animal origin are pancreatic trypsin, chymotrypsin, pepsin and rennin. Pepsin is an acidic protease that is found in the stomach of almost all vertebrates. Plant Proteases: Papain, bromelin, keratinases, and ficin are some of the well-known proteases of plant origin. Microbial proteases: microbial community is preferred over the others for the large scale production of proteases due to their fast growth and simplicity of life for the generation of new recombinant enzymes with desired properties Fungal proteases is advantageousFungal proteases: Fungal proteases magnetized the interest of researches due to high diversity, broad substrate specificity, and stability under extreme conditionsit offers an advantage of separation of mycelium by simple filtration. Fungal proteases can conveniently be produced in solid-state fermentation process. Fungal proteases are also used in for modifying food proteins and various other industrial applications.Sources of commercially significant proteasesTo meet commercial demands, large scale production of these enzymes became necessary and hence several sources were explored including fungi. The fungi possess diverse habitat, grow ubiquitously and produce various proteins/enzymes their survival. Among these enzyme proteases.Based on habitat fungi are classified as psychrophilic, mesophilic and thermophilic emerged as potential sources of commercial enzymes including proteases.Psychrophilic fungi: capable in producing cold tolerant protease.Several deep sea fungi are capable in producing psychrophilic protease including Aspergillus terreus, Beauveria brigniartii and Acremonium butyri.used in food processing,fruit and milk processing industries.

Thermophilic fungi:capable in producing commercial protease that act in higher temperature such as Canariomyces thermophila, Thermomyces ibadanensis, Talaromyces thermophiles, Myriococcum and Dactylomyces thermophiles.These proteases not only offer catalytic activity inhigher temperature but also possess longer shelf lifeand provide ease in storage.It has applications in leather ,detergent, biofuel, waste treatment, textile and fabric and biotechnological applications.

Mesophililic fungi :The mesophilic fungal strains are also competent in production of large scale of commercial protease enzymes. The major class of mesophilic fungi is Aspergillus which contribute more than 25% of protease produced from fungal source.Have applications in paper,pulp,leather,textile,detergent,agriculture,animal feed and food processing indutries.Protease in food processingFood processing utilizes several enzymes for production of quality and nutritional food products. Proteases have important roles in baking, brewing and in the production of various oriental foods such as soy sauce, miso, meat tenderization and cheese manufacture.Further, processing of fruits and storage of their juices for long shelf life need enzyme treatment and primarily protease are employed. Preparation of milk products and candies need complete processing catalysed by series of enzyme including protease.

Beverage industry both soft and hard drink need a complete processing of substrate for elegant flavour and shelf life of product. Processing of tea, coffee and coca needed a precise oxidation of raw material (ripen seeds, leaves and berry) to produce complete products and enzyme such as protease play crucial role. Ethanol is product of sugar fermentation carried out by series of biochemical reactions catalysed by group of enzyme including different type of proteases

Protease in textile industryAnother most significant area of commercial application of protease is textile industry where a final elegant texture is provided by enzyme treatment. Silk is processed by thermostable protease to remove gum and other impurities lies of core protein fibre on silk. Silk degumming a growing industry, enormously utilize protease and results in high quality silk. Synthetic fabric also subjected to protease treatment for elegant and smooth finish. Fungal proteases are key enzyme in fabric industry since decade and growing tremendously. Indian sericulture has grown double in last one decade and consumption of protease also enhances in several folds. Use of such method not only offer good quality fabric but also impart mechanical strength to fibre. Use of protease minimizes chemical detergent associated with large scale of environment pollution.

Protease in leather makingLeather is prime commodity for Indian in earning foreign currency and India is the second largest exporter of processes and unprocessed leather on world map after chinaLeather processing involves several steps such as soaking, dehairing, bating, and tanning. Old and conventional methods used are less efficient and utilized massive amount of chemical that leads lead to environmental pollution.Several studies have suggested that the enzymatic processing of leather is environment friendly and yield better quality leather. Leather making which primarily carried out at higher temperature involves several thermostable proteases. Thermophilic fungi have emerged as potential sources for leather processing Further, cleaning of hair and their biological digestion had yielded in several vital amino acids used as dietary supplementSeveral studies have been carried out to reuse of these potential enzyme after immobilization for leather making

Proteases as detergentsBiological detergent had great attention in current scenario primarily protease. Both domestic and industrial detergents are having major constituents from protease. Proteases are one of the standard ingredients of all kinds of detergents ranging from those used for household laundering to reagents used for cleaning contact lenses or denturesThe biological detergent are primarily used in cleaning of large boiler in industries, hospital,poultry industry.Discovery of thermostable protease further enhanced efficiency of biological detergent. In modern days both domestic and industrial detergent are utilizing protease in higher extent. In order to meet commercial demand fungal enzymes have become key source for detergents. Fungal alkaline proteases are advantageous due to the ease of downstream processing to prepare a microbe-free enzyme.

Therapeutic applications The medicinal application of protease for diagnostic and therapeutic is widely accepted and several enzymes are in use since many years. Proteases are primarily associated with development of anticancer-caspase, anti-inflammatory-Serratiopepetidaseses, antimicrobial-cytotoxic nature,clot dissolving agents-thrombolytic. Oral administration of protease from Aspergillus oryzae (Luizym and Nortase) has been used as a digestive aid to correct certain lytic enzyme deficiency syndromes.

REFERANCES..Izabel Soares, Zacarias Tavora, Rodrigo Patera Barcelos and Suzymeire Baroni (2012). Microorganism- Produced Enzymes in the Food Industry, Scientific, Health and Social Aspects of the Food Industry, Dr. Benjamin Valdez (Ed.), ISBN: 978-953-307-916-5, InTech.J. Srilakshmi, J. Madhavi, Lavanya S, Ammani K(2014) Commercial Potential of Fungal Protease: Past, Present and Future Prospects. J.Pharmaceutical , Chemical and Biological Sciences, 2(4): 218-234.Rao Mala et.al,(1998) Molecular and Biotechnological Aspects of Microbial Proteases. J.microbiol mol biol rev. 62(3): 597635. V. N. Jisha et al. (2013) versitality of microbial proteases.J. Advances in Enzyme Research1(3):39-51

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