Abdul Razak, Che Nyonya

Universiti Putra Malaysia Institutional Repository

FOR Category Fl0800: Biological SciencesSCREENING, ISOLATION ANDCHARACTERISATION OF LYPOLVTIC ANDPROTEOLYTIC MICROBES AND ENZYMESC.N.A. Razak.Faculty of Science and Environmental StudiesUniversiti Putra Malaysia, 43400 UPM, Serdang, Selangor,MalaysiaKeywords: lipolytic and proteolytic microbes, prote-ases, lipases, characterisation, purification.IntroductionMicrobial lipases and proteases constitute important groupsof biotechnologically valuable enzymes due to the versatilityof their applied properties and ease of mass production. Bothenzymes have been the subject of intensive research withconsiderable emphasis on biotechnological aspects. Lipasesare enzymes which catalyse hydrolysis of water-insolubleacyl esters, trans- and interesterification reactions leading tothe production of altered lipids. Proteases are enzymes whichcatalyse the hydrolysis of peptide bond. Industrially, prote-ases and lipases are widely used in food production, deter-gent, chemical and pharmaceutical industries. In view oftheir importance, during the last 7 years, our group havestarted an intensive screening programme for proteolytic andlipolytic microbes from local environments. New microbialenzymes with new properties may permit better understand-ing of the enzymes and exploitation of their biotechnological'potential.Materials and MethodsPrimary screening for lipolytic microbes was done usingtributyrin and triolein agar. Skim milk agar plates were usedfor proteolytic microbes. Lipase activity was determined ac-cording to Samad et al. (1990). Protease activity was assayedaccording to method described by Rahman et al. (1993).Results and DiscussionOver 100 lipolytic and proteolytic microbial isolates, mainlybacteria and fungi, were isolated and purified from variouslocations, such as dumping places, palm oil mill effluents(POME), soils and drains. The cultural and nutritional fac-tors affecting the growth of selected microbes and their en-zyme production were studied in detail (Razak et al. 1997a).For microbial lipases, detailed studies were done on Rhizo-pus rhizopodiformis, R. oryzae (thermophilic) and R. oryzae(mesophilic), (Razak et al. 1997b). Both the intracellu-, lar/membrane bound and extracellular lipases from the threefungi were purified and characterised. Two bacterial lipasesfrom Pseudomonas sp. were studied in detail. Lipase pro-duction by immobilised cells were also investigated, the ma-trix employed were alginate, polyurethane and poly-HEMA(Salleh et al. 1996). For microbial proteases, focus was onthermostable proteases. Most of the potential protease pro-ducers isolated belonged to Bacillus sp. A detailed study wasdone on B. stearothermophilus strain F1, since it producedremarkable amount of protease under alkaline condition.The protease from these bacteria has been purified and char-acterised. It showed very high thermostability up to 80°C.Deteregency studies on the protease showed that it washedbetter than Savinase (a commercial enzyme) at temperatureshigher than 50°C suggesting its potential as a detergent en-zyme. Strains improvement through mutagenesis to improvethe enzyme's yield was also studied (Razak et al. 1996).Currently, work is being carried out to clone and sequencethe protease gene from B. stearothermophilus strain Fl.ConclusionsThree fungal lipases were purified and characterised. Theirgrowth and lipase production parameters were determined.Higher lipase yield was achieved with immobilised cells.Protease from B. stearothermophilus strain FI was purifiedand characterised. The protease is very thermostable, stablein alkaline condition and display remarkable washing ability.ReferencesRahman, R.N.Z., Razak, C.N.A., Ampon, K., Basri, M., Wan Yunus,W.M.Z. and Salleh, A.B. 1993. Purification and characteriza-tion of a heat-stable alkaline protease from Bacillus stearother-mophilus F1. Appl. Microbiol. Biotechnol. 40: 822-827.Razak, C.N.A., Tang, S.W., Basri, M. and Salleh, A.B. 1997a. Pre-liminary study on the production of extracellular protease from anewly isolated Bacillus sp. (No.1) and the physical factors af-fecting its production. Pertanika J. Sci. & Technol. 5(2): 169-177.Razak, C.N.A., Salleh, A.B., Musani, R. Sarnad, M.Y., Basri, M..1997b. Some charac~eristics of lipases from thermophilic fungiIsolated from palm oil mill effluent. J. Mol. Cat. B. Enzymatic. 3:153-159.SaHeh, A.B., Zakaria, Z., Razak, C.N.A., Ampon, K, Basri, M. andYunus, W.M.Z. 1996. Polyurethane as a matrix for immobilisa-tion of lipolytic. Biosci. J. 8(1): 15-21.Samad, M.Y.A., Salleh, A.B., Razak, C.N.A., Ampon, K., Yunus,W.M.Z. and Basri, M. 1990. A lipase from a newly isolatedthermophilic Rhizopus rhizopodiformis. World J. Microbiol.Biotechnol. 6: 390 - 394.Supported by IRPA Grant 09-02-04-0002219

Screening, isolation and characterisation of lypolvtic and proteolytic microbes and enzymes

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Screening, isolation and characterisation of lypolvtic and proteolytic microbes and enzymes

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