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EFECTUL PH-ULUI SI ATEMPERATURII ENZIMELORASUPRA EPURARII APELOR

UZATESimona SIMON (NISTE), drd,

Universitatea Tehnic Cluj-NapocaTiberiu RUSU,Profesor,

Universitatea TehnicCluj-NapocaAncuta BORLEA (TIUC) ), drd,

Universitatea Tehnic Cluj-Napoca

Rezumat:Datorit necesitatii de de mbuntire atehnicilor de remediere biologice, tehnologiaenzimatic a primit o atenie sporit. Activitateaenzimelor n procesul de curare a apelor uzate esteputernic afectatde modificarea pH-ului i de variaiade temperatur.O temperaturmult prea ridicatsauprea scazut sau o variatie a pH-ului va duce ladistrugerea de activitii enzimatice.

Cuvinte cheie:pH, temperatur, enzime, epurare, apuzat

1. INTRODUCEREEnzimele sunt catalizatori biologici,

care accelereaz viteza unei enzime dintr-oreacie biochimic. Fr aceti

biocatalizatori multe din procesele importanteale vieii nu se pot ntmpla, de asemenea,sunt foarte specifice, n funciie lor, deoarecefiecare enzim poate ajuta o singur reacie.Enzimele nu sufer schimbri atunci cnd iiexercit funcia de biocatalizator, aceleaienzim poate fi utilizat de mai multe ori.

Enzimele reduc energia de activare care esteesenialpentru a ncepe orice tip de reaciechimic. Performanei generale a unei enzimedepind de diveri factori, cum ar fitemperatura, pH-ul, care pot afecta formaenzimei i vor face enzima mai puin eficacesau chiar inutil.

2. EFECTUL pH-ULUI ASUPRAACTIVITATII ENZIMATICE

Modificri ale pH-ului sau aciditateamediului poat avea loc datorita factorilorexterni care ar putea modifica sau inhiba total

EFECT OF pH ANDTEMPERATURE OF ENZYMES

ON BIOLOGICAL

WASTEWATER TREATAMENTSimona SIMON (NISTE), PhD,Tehnical University Cluj-Napoca

Tiberiu RUSU,Professor, TehnicalUniversity Cluj-Napoca

Ancuta BORLEA (TIUC) ),PhD,Tehnical University Cluj-Napoca

Abstract: With a necessity of improvement inbiological remediation techniques, enzyme technologyhas been receiving increased attention. The activity ofenzymes in cleaning wastewater process is stronglyaffected by changes in pH and temperature.Too hightor low temperature or pH will cause the destruction ofenzyme activity.Keywords: pH, temperature, enzymes, tratament,wastewater

1. INTRODUCTION

Enzymes are biological andproteinaceous catalysts, which speed up therate of a biochemical reaction.Withouthenzymes many of the important processes oflife could not happen are also very specific intheir function because each enzime has onlyone reaction that it can help. Enzymes are notchange when they perform their function,same enzyme can be used over and overagain. They reduce the activation energy thatis essential for starting any type of chemical

reaction. With a low energy requirement foractivation, the reaction takes place faster. Theoverall performance of an enzyme dependson various factors, such as temperature, pH,who may affect the shape of an enzymemolecule and will make the enzyme lesseffective or possibly even useless.

2. pH EFFECTS ON ENZYMESACTIVITY

Changes in the pH or acidity of theenvironment can take place that would alter


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enzima de la cataliza unei anumite reacii.Enzimele sunt afectate de modificarea pH-ului [1]. Valoarea pH-ului cea mai favorabileste punctul n care enzima este cea maiactiv, este cunoscut ca pH-ul optim. Nivelul

pH-ului optim poate s difere n funcie defiecare tip de enzim. (Table1).

or totally inhibit the enzyme from catalyzinga reaction. Enzymes are affected by changesin pH[1]. The most favorable pH value is the

point where the enzyme is most active, isknown as the optimum pH.This pH optimum

can be diffrent for each enzym(Table1).

Table 1.pH optimum[1]

Enzyme PH optimum

Lipase 8

Amylase 6.7-7

Catalase 7

Valorile extrem de mari sau mici, alevalorii pH-ului duc la pierderea complet aactivitii pentru cele mai multe enzime, pH-ul este, de asemenea, un factor de stabilitate aenzimelor i poate avea un efect asupra striide ionizare a acizilor , bazelor sauaminoacizilor. n cazul n care starea deionizare de aminoacizi ntr-o protein estemodificat, atunci legaturile ionice care ajut

pentru a stabili forma 3-D a proteinei poat fimodificate. Acest lucru poate duce la

recunoaterea proteinei modificate i enzimaar putea deveni inactiv.Table 1. pH optim[1]

Modificrile pH-ului nu afecteaznumai forma unei enzime, aceasta poatemodifica, de asemenea, forma sau

proprietile responsabile de substrat, astfelnct substratlul nu se poate lega la situsulactiv sau nu poate efectua cataliza.

Extremely high or low pH valuesgenerally result in complete loss of activityfor most enzymes, pH is also a factor in thestability of enzymes and can have an effect ofthe state of ionization of acidic or basicamino acids. If the state of ionization ofamino acids in a protein is altered then theionic bonds that help to determine the 3-Dshape of the protein can be altered. This canlead to altered protein recognition or anenzyme might become inactive.

Changes in pH may not only affect theshape of an enzyme but it may also changethe shape or charge properties of the substrateso that either the substrate can not bind to theactive site or it can not under go catalysis.

Fig.1.Efectul pH-ului [4]

pH-ul mediului n care enzima

Fig. 1.pH effect[4]

The pH of the medium in wich the enzymeworks affects the rate of enzyme activity.Tere


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funcioneaz afecteaz rata de activitate aenzimei. Sunt enzime care pot fi active pe oscara a pH-ului de la 2 la 9. Unele dintreenzime pot fi active n mediu acid iar altele inmediul bazic. Dar cea mai mare parte a

enzimelor activeaz ntr-un mediu neutrupentru a avea o activitate enzimaticputernic.PH-ul poate avea un impact major asupraactivitii enzimatice fcnd ca o enzim sfuncioneze mai bine sau mai ru.

3. EFECTUL TEMPERATURIIASUPRA ACTIVITATIIENZIMATICE

Temperatura, o msura intensitii decldureste un factor important n activitateacare caracterizeazviteza enzimei. O reacieenzimatic este influenat de temperatur.Fiecare enzim are, de asemenea, otemperatur optim, care favorizeaz oconformaie nativpentru activitatea maxim.Avnd n vedere consideraiile de mai sus,fiecare enzimare o gam de temperatuara ncare poate atinge o ratmaxima activitii.Aceast maxim este cunoscut ca

temperatura optim a enzimelor, viteza dereacie a unei enzime catalizate crete pemsur ce temperatura se apropie de niveluloptim. O cretere cu zece grade atemperaturii va crete activitatea celor maimulte enzime cu 50 pana la 100%. Variaiilede temperatur de reacie mici cu 1 sau 2grade pot introduce modifiri de la 10 panala 20% n rezultatele aciunii enzimei. ncazul reaciilor enzimatice, acest lucru estecomplicat de faptul cmai multe enzime sunt

afectate de temperaturile ridicate [2].n afara acestui interval de temperaturenzima devine inactivi este declarata ficomplet inhibat. Acest lucru se ntmpldeoarece, schimbriile de temperaturafecteazaprovizionarea cu energie suficient

pentru a rupe legaturile intramoleculare.Enzimele sunt proteine iar temperatura esteunul dintre factorii care afecteaz enzimele

pentru ca, o data cu creterea temperaturii,energia cinetic a moleculelor crete, acestlucru nseamn c moleculele se mica mairepede, astfel nct exist anse mari pentru

are enzyme that can be active betuin a pHrange of 2 to 9. Some of enzime can be activein acidic medium and some in alcalinemedium.But most part of enzime have aneutral medium to have a powerfull activity.

The pH can cause enzyme to performbetter or worse. If the enzyme is placedoutside of the range the protein willdenaturate or lose its function.

3. EFFECTS OF TEMPERATUREON ENZYMES ACTIVITY

Temperature, a measure of intensity ofheat is an important factor in the activity ofenzymes.The velocity of an enzyme reactionis influenced by temperature. Each enzymehas also an optimal temperature that favor thenative conformation for maximum activity.Given the above considerations, each enzymehas a temperatuare range in which a maximalrate of reaction is achieved. This maximum isknown as the temperature optimum of theenzyme, the rate of an enzyme-catalyzedreaction increases as the temperature is

raised. A ten degree rise in temperature willincrease the activity of most enzymes by 50to 100%. Variations in reaction temperatureas small as 1 or 2 degrees may introducechanges of 10 to 20% in the results. In thecase of enzymatic reactions, this iscomplicated by the fact that many enzymesare adversely affected by hightemperatures[2].

Outside that temperature range theenzyme is rendered inactive and is said to be

totally inhibited. This occurs because as thetemperature changes this supplies enoughenergy to break some of the intramolecularattractions.

Enzymes are proteines andtemperature affects enzymes because astemperature incrase, the kinetic energy ofmolecules increase, this means that themolecules are mouving about quicker so thatthere is big chance for substrate moleculescoming into contact with the active site of the

enzymes and too hight of temperature willcause proteins to denaturate or to essentially


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molecule i substrat care intrn contact cusitusul-ul activ al enzimelor iar temperatura

prea mare va provoca denaturarea enzimelor.Pstrarea i utilizarea enzimei la temperaturifoarte ridicate pentru o perioad lung de

timp va duce la pierderea enzimei.

fall apart due to kinetic energy overcomingthe strenght of the molecular bonds holdingthe enzyme together.

Holding the enzyme at the highttemperture for a long period of time may

cook the enzyme.

Fig. 2.Efectul temperaturii [4]

4. IMPORTANA AMESTECULUIENZIMATIC N TRATAREAAPELOR UZATE

Concentraia enzimelor pentru procesulbiologic de curatare al apelor uzate este unfactor foarte important i poate safecteazerata de reacie enzimatic, frenzime acesttip de proces poate merge foarte ncet, dar cuenzime rata este direct proporional cucantitatea de enzime care este prezent.Microorganismele pot modifica cantitatea deenzime care influeneaz sinteza lor i potcrete viteza de catalizatizare.Activitatea enzimelor este puternic afectat

de modificarea pH-ului i a temperaturii.Este necesar ca pentru optimizareatemperaturii i a pH-ul, s se ia n calculactivitatea enzimatic.Majoritatea enzimelor au o temperaturoptim, care poate fi asemanatoare cu cea aorganismului din care a fost izolat enzima.Anumite organisme se dezvoltfoarte bine latemperatura camerei iar enzimele provenitedin aceste microorganisme au o activitateaenzimaticmaximla temperatura de 30-40

C. La temperaturi ridicate acestemicroorganisme ii incetinsc activitatea, la

Fig. 2.Effect of temperature [4]

4. IMPORTANCE OF ENZYMESIN WASTEWATERTREATAMENT

Enzime concentration for the

biological wastewater process is a veryimportant factor and can affects the rate ofenzimatic reaction, withouth enzime this tipeof process can go very slowly but withenzymes the rate is directly proportional tothe amount of enzume that is present. Inaddition , there reaction will only incrase ifthe substrate present are in excess amounts,cells can alter the amount of enzymes byinfluencing their synthesis and breack downand the speed of catalization increases.

The activity of enzymes is stronglyaffected by changes in pH and temperatures.Itis necessary to optimize the pH andtemperature, calculating the enzyme activityrates at each pH and temperature. Aminoacids constitute the active catalytic region ofevery enzyme and the various side chains ofthe basic and/or acidic amino acids can existin either of two forms: ionized or protonated.Consider the catalytic mechanism of a

particular protease to be controlled by twoglutamic acid residues, one ionized and theother protonated. Any pH lower than the


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fel intamplndu-se i cu enzimele care nceps se denaturezei i s ii piard activitateadin timpul proceselor de epurarea a apeloruzate.Enzimele pot avea un efect deosebit n

tratarea biologic a apelor uzate volumul denmol n exces, organismele care se pierd nprocesul de tratare a apei uzate, nlaturareamirosurilor, reducerea timpului de maturareal compostului, descompunerea grsimilor ia uleiurilor minerale. [5]

CONCLUZIIBiotehnologia modern continu s

dezvolte instrumente noi, precise pentru ambunti o gam larg de procese de

producie, de asemenea, poate ajuta lameninerea sau restabilirea echilibrului prinoferirea unor instrumente, metode, ioportuniti de a opri sau a reduce impactulactivitii umane asupra mediului. Enzimelesunt catalizatori foarte eficieni pentrureaciile biochimice, acestea joac un rolfoarte important n facilitarea i protejeareamediului care pot duce la crearea unorsisteme de producie mai durabile.Treatamentul apelor uzate biologice cuenzime este o soluie foarte bun pentru

protecia mediului, deoarece produselechimice pot fi nlocuite cu produse ecologice,

bio, cu o eficiencrescut.NOT: Aceast lucrare a beneficiat de

suport financiar prin proiectul " Studiidoctorale n tiine inginereti n scopuldezvoltrii societii bazate pe cunoatere -SIDOC ", contract:POSDRU/88/1.5/S/60078,

proiect cofinantat din Fondul Social

European prin Programul OperationalSectorial Dezvoltarea Resurselor Umane2007-2013.

BIBLIOGRAFIE[1] B Holum, J.: Elements of General andBiological Chemistry, 2nd ed., 377, Wiley,

NY[2] Bennett, T. P., and Frieden, E.: ModernTopics in Biochemistry, pg. 43-45,Macmillan, London (1969).

[3] Logan, R. H., I Chemistry, Dallas CountyCommunity College District, North Lake

optimum would protonate the ionized residuewhile any pH higher than the optimum wouldionize the protonated residue leading todecreased activity. Most enzymes have anoptimum temperature, which may be related

to the type of organism from which theenzyme was isolated. Some organisms growwell near room temperature and so theirenzymes are most active at a temperaturearound 3040 C. At low temperatures, all themolecules in the solution slowdown and sodoes the enzyme catalyzed reaction while athigh temperatures, the thermal movement ofthe molecules become too great for theenzyme to hold its shape or conformation andso it begins to denature and lose its activity

[4] in the wastewater treatament process.Enzymes can have an excellent effects

on biological wastewater applications such asvolume reduction of excess sludge, organismwasted water treatment, bad odorremovement, but also promote composting toreduce ripening time, glowing plants(improving soils), purifying ponds and lakeswater (activating aquatic microbes),decomposing fat and mineral oil. [5]

CONCLUSIONModern biotechnology continues to

develop new, precise tools to improve a widerange of production processes also can helpmaintain or restore the balance by providingtools, methods, and opportunities to stop orlessen the impact of human activity on theenvironment.

Enzymes, are very efficient catalystsfor biochemical reactions, play a very

important role in facilitating moreenvironmentally sound production andeducation and making production systemsmore sustainable.

Biological wastewater treatament withenzyme is a very good solution forenvironment protection, because thechemichal products can be replaced withenvironmentally friendly bio products with ahight eficienticy.

ACKNOWLEDGEMENTS: Paper preparedfor the Project "Doctoral studies in


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College[4] Whiteley, C.G., Lee D.-J., Enzymetechnology and biological remediationDepartment of Biochemistry, Microbiologyand Biotechnology, Rhodes University,

Artillery Rd., P.O. Box 94, Grahamstown ,South Africa, Department of ChemicalEngineering, National Taiwan University,Taipei, Taiwan, October 2005[5] Shun'ichiw, I., Water treatmenttechnology. On volume reduction, biologicaltreatment, and deodoring of excess sludge byusing complex enzymes, Japan,2005

engineering science to develop knowledge-based society - SIDOC" ContractPOSDRU/88/1.5/S/60078.

REFERENCES

[1] B Holum, J.: Elements of General andBiological Chemistry, 2nd ed., 377, Wiley,NY[2] Bennett, T. P., and Frieden, E.: ModernTopics in Biochemistry, pg. 43-45,Macmillan, London (1969).[3] Logan, R. H., I Chemistry, Dallas CountyCommunity College District, North LakeCollege[4] Whiteley, C.G., Lee D.-J., Enzymetechnology and biological remediation

Department of Biochemistry, Microbiologyand Biotechnology, Rhodes University,Artillery Rd., P.O. Box 94, Grahamstown ,South Africa, Department of ChemicalEngineering, National Taiwan University,Taipei, Taiwan, October 2005[5] Shun'ichiw, I., Water treatmenttechnology. On volume reduction, biological

treatment, and deodoring of excess sludge by

using complex enzymes, Japan,2005

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