2

1. T VN

Enzym l nhng protein c kh nng xc tc mnh. Enzyme c tng hp bi cc t bo sng v tt c cc vi sinh vt, chng tham gia trong cc phn ng ha hc lin quan n qu trnh chuyn ha [6]. Enzyme c th xc tc cc phn ng ha hc bn trong t bo cng nh cc phn ng ngoi t bo. Cc phn ng do enzyme xc tc cng din ra trong thc phm, v v th c th lm tng cht lng hoc lm h hng sn phm. Enzyme c s dng trong nhiu qu trnh sn xut, c bit l trong cng ngh thc phm. Cng ngh enzyme ra i l mt bc pht trin ng dng ca enzyme. Ngy nay, vic nghin cu enzyme bc vo mt giai on mi, mt giai on c s tch hp vi nhiu ngnh khc nhau nh ha hc protein, sinh hc phn t do c c nhng hiu bit y hn v tnh cht ha hc, cu trc, ng hc v tim nng ng dng ln ca enzyme. Nhng pht trin mi nht trong cng ngh enzyme nhm lm cho chng c th thch nghi vi iu kin mi ca qu trnh ch bin, t cho php m rng hn na vic s dng chng trong nhiu ngnh cng nghip khc nhau [6].Hin nay trn th gii, vic sn xut ch phm enzyme cc loi v ang pht trin mnh m trn quy m cng nghip. V thc t c rt nhiu ch phm enzyme bn trn th trng th gii, cc ch phm ny c khai thc v tinh ch c mc tinh khit theo tiu chun cng nghip v ng dng sn xut nh protease, amylase, pectinase, cellulase Trong , pectinase c coi l mt trong nhng enzyme c nhiu ng dng trong cc ngnh cng nghip khc nhau: trong cng nghip ch bin thc phm (nh sn xut nc qu, sn xut ru vang, sn xut cc loi mt qu, sn xut c ph, ca cao), cng nghip dt, cng nghip giy, x l mi trng...

Pectinase l h enzyme xc tc s thy phn cc polymer pectine. S phn hy pectine trong t nhin thng xy ra khi tri cy chn. Nhng enzyme ny v vy c mt vai tr ht sc quan trng trong qu trnh bo qun rau qu. Enzyme pectinase cng c ng dng nhiu trong qu trnh ch bin thc phm, c bit l kh nng lm trong nc qu. Vic kim sot hot ng ca enzyme pectinase cng c th kim sot c cc tnh cht ca sn phm nh nht, trong, Pectinase l h enzyme bao gm nhiu loi enzyme c phn loi theo c ch tc dng ln c cht [14].Pectinesterase (PE) xc tc s thy phn cc nhm methyl ester, thng tn cng nhm ester methyl ( - COOCH3) ca n v galacturonate nm k n v khng b ester ha (-COOH t do), phn ct nhm methoxy to acid pectinic hoc acid pectic, gii phng methanol. Polygalacturonase (PG) cn c tn gi l poly -1,4-galacturoniglucanohydrolase xc tc s phn ct cc mi lin kt 1,4-glycosid. Cc exo-PG (exo-poly 1,4-D-galacturonide) galacturonohydrolase phn ct t u khng kh v endo-PG (endo-poly1,4-D-galacturonide) glycanohydrolase, tn cng ngu nhin vo gia mch c cht. Polygalacturonase l mt phc h enzyme gm nhiu cu t thng c tnh c hiu cao i vi c cht [14].Pectinase c mt trong hu ht cc loi qu, c bit giai on chn. Polygalacturonase t gp trong thc vt nhng c ch yu nm mc v vi khun, c bit l nm mc Aspergillus niger, Aspergillus awamori [14].Pectinase c vai tr quan trng trong cng ngh thc phm. Tuy nhin, Vit Nam, cha c nhiu nhng nghin cu v sn xut pectinase. Vic tm hiu v h enzyme ny cng nh nhng iu kin nh hng n vic tng hp cc enzyme trong h pectinase l rt cn thit.

1.1. Cc cng trnh nghin cu trong v ngoi nc

1.1.1. Cc cng trnh trong nc

Khi m mc ch s dng enzyme trong cc ngnh cng nghip ngy cng tr nn r rng hn th iu ny thc y khng t nhng nghin cu c th to ra cc ch phm enzyme thch hp. nc ta, cc nghin cu v pectinase a phn l tp trung hon thin iu kin nui cy sinh tng hp enzyme cao trong phi k n mt s cng trnh c cng b nh:

- Thu nhn enzyme pectinase t Asp.niger - tinh sch bng phng php lc gel & lc mng do Hunh Ngc Oanh, Trn Ngc Hng, Trng i hc Bch khoa, HQG TP. HCM tin hnh [1]. Ch phm enzyme pectinase c sn xut t chng nm mc Aspergillus niger trn mi trng c cha cht cm ng bt c rt sau 48 gi t hot cao nht 30,01(UI/g). Phn tch ch phm enzyme bng phng php lc gel s dng ct Bio Gel P 30 thu c mt peak c hot pectinase v vi tc chy qua ct 15ml/gi c kh nng phn tch tp cht tt hn tc 30 ml/gi. Tinh sch ch phm enzyme bng phng php lc mng (cross flow membrane) vi tc bm u vo 150rpm th tinh sch (tng 3,1 ln trc khi lc) cao hn tc 200rmp (c tinh sch ch tng 2,2 ln so vi trc khi lc).- Nghin cu enzyme cellulase v pectinase t chng Trichoderma viride v Aspergillus niger nhm x l nhanh v c ph do Trn Th Thanh Thun, Nguyn c Lng thc hin [3]. Nghin cu xc nh cc iu kin nh hng n qu trnh sn xut hai enzyme ny: iu kin ti u sn xut enzyme pectinase ca Aspergillus niger l: 2 ngy, m 62%, ging 8%. iu kin ti u sn xut enzyme cellulase ca Trichoderma viride l: 4 ngy, m 58%, ging 8%. Qua th nghim thc t nhn thy, v c ph phn hy trong 14 ngy, 60% m, 8% ging.1.1.2. Cc cng trnh ngoi nc

Nhiu li ch ca enzyme pectinase khi ng dng chng trong cc lnh vc sn xut khc nhau thc y nhng nghin cu nhm chit tch v tinh ch cc ch phm enzyme t cc ngun khc nhau. T cc nghin cu v thnh phn mi trng nui cy thch hp, iu kin nui cy sinh tng hp enzyme c hot cao n qu trnh tch v tinh ch to ra cc ch phm enzyme vi nhng c tnh ph hp cho cc ng dng trong cng nghip. Trong nhng nm gn y, th gii c rt nhiu nghin cu v pectinase t vi sinh vt v xc nh cc tnh cht ca cc ch phm enzyme thu c nhm to iu kin ng dng rng ri chng vo cc ngnh cng nghip khc nhau.- Mara A. Martos, Francisco Martinez Vazquez, Fernando O. Benassi v Roque A. Hours nghin cu nh hng kt hp ca cc iu kin nui cy kh nng sinh pectinesterase v polygalacturonase ca chng A. niger N 300 trn mi trng tng hp c cha pectine [8]. Kt qu nghin cu cho thy iu kin nui cy ti u tng hp polygalacturonase cao (t 1032 U/l) l pH 4.1, hm lng pectine 20 g/l, thi gian ln men l 74h. Ti iu kin ny, qu trnh tng hp pectinesterase l thp (15 U/l).- Vivek Rangarajan, M. Rajasekharan, R. Ravichandran, K. Sriganesh and V. Vaitheeswaran tin hnh nghin cu qu trnh tng hp pectinase t c cht l bt v cam sy kh v chit xut v cam c b sung ngun nit hu c v v c, s dng chng A.niger [11]. Kt qu cho thy hm lng pectinase cao nht trong mi trng chit xut v cam b sung peptone v mi trng bt v cam b sung sa u nnh. Hot lc endopectinase ln nht 6800 U/g t c khi nui cy chm trong mi trng chit xut v cam c b sung ngun nit hu c l peptone. Hm lng pectinase tng hp trong mi trng b sung ngun nit v c c bng phng php nui cy chm v nui cy trn mi trng rn u thp.- Aurora Martnez-Trujillo, Juan S. Aranda, Guillermo Aguilar-Osorio nghin cu v ng hc qu trnh tng trng, s gim c cht v qu trnh tng hp polygalacturonase ca Aspergillus flavipes FP-500 trong qu trnh nui cy lin tc [4]. Nghin cu thc hin trn mt s mi trng mono-, di-, tri- saccharide v xy dng c m hnh ng hc pht trin ca chng Aspergillus flavipes.- R R Siva Kiran, Rajesh Konduri, G H Rao, G M Madhu nghin cu ti u ha qu trnh tng hp endo-polygalacturonase bi chng Aspergillus niger t bin trn mi trng rn [10]. Nghin cu s dng m hnh Plackett-Burman v ti u ha bng cng c Doehlert ti u ha mi trng nui cy v hot lc tng hp endo-polygalacturonase l 4.266 U.- Evrim Takn, Eva Stratilov nghin cu v polygalacturonase tng hp bi 2 chng Aspergillus foetidus (EGEK145, EGEK635) trn mi trng rn v mi trng lng [5]. Kt qu nghin cu xc nh c mt s c im sinh ha ca hn hp enzyme sn xut bi 2 chng trn mi trng rn: pH thch hp: 4.4 4.8, nhit : 30 35oC. ng thi nghin cu cn so snh kh nng chu nhit, tc dng trn c cht pectate ca cc enzyme ca 2 chng.- M. Motallebi, H. Afshari Azad v M.R. Zamani nghin cu v qu trnh sn xut polygalacturonase bi chng Sclerotinia Sclerotiorum [9]. Kt qu cho thy iu kin ti u tng hp enzyme polygalacturonase l pectine: 15g/l, pH 5, thi gian: 4 ngy v nhit : 25oC. Nghec ng m

T in - Xem t in chi tit1.2. Tnh cp thit ca ti

Trong nhng nm gn y, vic nghin cu ci thin cc iu kin nui cy nhm thu nhn enzyme c hot tnh cao v t s dng chng trong sn xut cng nghip khng cn l mi. Enzyme pectinase cng c nghin cu v ng dng nhiu trong sn xut cc sn phm thc phm nh nc p qu, sn xut c ph, ru vang, v em li c hiu qu cao. Tuy nhin, vn cn nhng vn cn c gii quyt.S c mt ca pectinesterase l nguyn nhn gy ra cc vn trong sn xut nc qu. Nu enzyme ny khng b c ch sau khi tch chit dch qu bng cch v hot ha bi x l nhit hoc lnh ng th cc phn t pectine s b ester ha v s ng t bi cc ion Ca2+ trong dch p, lm cho sn phm nc qu b phn lp, mt i trng thi l lng ca nc qu c[14] Cc cht to hng, cc vitamin trong nc qu li nhy cm bi nhit. Hn na, nu x l v hot enzyme pectinesterase th cng lm v hot cc enzyme khc cn thit cho qu trnh sn xut, trong c enzyme polygalacturonase. y l enzyme cn thit trong h pectinase c kh nng polymer ha phn t pectine, lm gim nht ca nc qu p v tng hiu qu p cng nh tng cht lng cho cc sn phm t qu. Do , mt h enzyme pectinase c hot lc cc enzyme theo ng yu cu sn xut l mt mong mun ca cc nh sn xut cc sn phm t nguyn liu qu.Aspergillus niger l chng vi sinh vt c kh nng sinh tng hp pectinase cao, c s dng rng ri sn xut enzyme pectinase. Qu trnh sinh tng hp pectinase, s pht trin ca t bo, s hnh thnh bo t nm mc c th b nh hng bi thnh phn mi trng, cc iu kin nui cy nh nhit , pH, thi gian nui cyXut pht t nhng vn trn, ti chn ti nghin cu ca mnh l Nghin cu kh nng tng hp pectinesterase v polygalacturonase ca Aspergillus niger nhm kho st iu kin nui cy thch hp cho qu trnh sinh tng hp pectinesterase thp v polygalacturonase cao.T ti ny c th m ra thm mt trin vng ca vic thu nhn enzyme c hot lc cao vi cc tnh cht thch hp cho sn xut. iu ny khng ch hiu qu kinh t m cn m ra kh nng gii quyt cc vn v cht lng sn phm cng nh gii php k thut mt cch hiu qu.

1.3. ngha khoa hc v thc tin ca ti

1.3.1. ngha khoa hc

Thit lp cn c/c s khoa hc cho vic thay i iu kin mi trng nui cy nhm thu nhn enzyme pectinesterase v polygalacturonase vi hiu qu cao t cc chng nm mc c phn lp t cc loi qu giu pectine.

1.3.2. ngha thc tin ca ti

Vi vic thay i iu kin mi trng nui cy sinh tng hp h enzyme thu nhn ch phm enzyme vi hiu sut cao, hot cc enzyme trong h nh mong mun, ph hp vi tng quy trnh sn xut cc loi sn phm khc nhau, gp phn p ng c nhu cu s dng chng trong sn xut cng nghip ph bin hn. ng thi gp phn ci tin c quy trnh sn xut, nng cao cht lng sn phm, m ra mt kh nng mi cho vic s dng mi trng t nhin thay th nui cy nm mc c hiu qu kinh t cao.

2. I TNG V PHNG PHP NGHIN CU

2.1. i tng nghin cu

- i tng nghin cu l chng Aspergillus niger c kh nng sinh tng hp enzyme pectinase ngoi bo phn lp t cc loi qu giu pectine.2.2. Phng php nghin cu

2.2.1. Phng php vi sinh

*Phn lp nm mc c kh nng sinh tng hp pectinase ngoi bo caoPhng php phn lp dng kim nhn: S dng phng php ny phn lp nm mc pht trin trn c cht giu pectine.Cch lm: S dng que nhn nht bo t chuyn sang mi trng phn lp. Nui cy bo t nhit 250C, quan st s ny mm ca bo t hng ngy n khi hnh thnh khun lc th chuyn sang mi trng thch nghing.* Phng php xc nh kh nng sinh pectinase Nguyn tc ca phng php: Hot tnh enzym pectinase c nh gi trn c s mc thu phn pectin dc tc dng xc tc ca enzym thng qua ln ca vng phn gii bng dung dch ch th lugol. Pectinase l mt enzym cm ng nn khi ta ln men cc chng nm mc phn lp c trong cc mi trng c pectin th s sinh pectinase, khi ta sng lc bng phng php o vng phn gii.

Cch xc nh:

Chng ging sau khi hot ha c nui cy trong mi trng trong cc ng nghim. Thc hin nui cy trong my lc 300C trong 3 ngy, dng khoan nt c l trn a thch v cho dch ln men vo a thch. cc hp pectin ny 370C, sau 24h ly ra nh dung dch ch th lugol ln mt thch. Sau , xc nh hot tnh enzym pectinase bng cch o ln vng phn gii pectin trn mi trng.* Phng php nui cy thu nhn enzym pectinase

2.2.1.1. Phng php nui cy b mt t mi trng rnMi trng s dng nui cy VSV thu nhn pectinase l bt v cam nh l ngun c cht. Ngun dinh dng b sung thng l cc mui ammonium, phosphoric m mi trng phi nm trong khong 60%. Nm mc thng c nui cy 30oC v trong thi gian khc nhau, v hm lng ngun c cht khc nhau. Sn phm ln men thu c l ch phm enzyme th v em i xc nh hot lc ca cc enzyme PG v PE.2.2.3.2. Thu nhn ch phm enzyme t canh trng b suMi trng nui cy l mi trng lng cha dch chit v cam, b sung cc ngun dinh dng nit, phosphoS tch t enzyme trong mi trng c bt u khi s pht trin ca nm mc gn t n pha n nh, khi mi trng b acid ho mnh v khi lng phospho v c c s dng hon ton. pH ca mi trng nui cy thng t t 6-7,2 l thch hp. i vi nm mc, pH kim km hm s tng hp sinh khi v s tch ly enzyme pectinase. pH=4 c ch hon ton s tch ly enzyme pectinase. Khi pH dch v pha acid, ngay c khi pH nm trong khong 4,5-5,0, tuy s to thnh sinh khi khng b nh hng nhng s to thnh enzyme pectinase b km hm. Kho st thi gian ln men t 24 120h, pH ban u ca dch nui cy 3.5 6.5, hm lng c cht b sung 5 20 g/l (tnh thep pectine)Vt liu gieo cy c th l si nm 24, 32 v 48h tui v vi hm lng t 2-10%. i vi A. niger, vt liu gieo cy l si nm c s b trong mi trng dinh dng cho n khi bt u nt nanh bo t. Thi gian s b thng l 38 42h. Lng si nm em gieo cy thng l 2%. Trong qu trnh nui cy, hm lng cc cht ho tan trong mi trng thng gim t 6% xung cn 1,5-1,8%.Sau tch sinh khi t bo bng phng php lc li tm v em dch enzyme th i xc nh hot tnh ca PG v PE.2.2.2. Phng php sinh ha

2.2.2.1. Xc nh hot enzyme bng phng php xc nh sn phm cui- Xc nh hot lc ca polygalacturonase bng cch enzyme vi dung dch c cht chun (acid pojygalacturonic) trong iu kin thch hp. Xc nh lng cc nhm kh hnh thnh bng phng php Dinitrosalicylic acid [6].- Xc nh hot lc ca pectinesterase bng cch enzyme vi dung dch c cht chun ri xc nh lng nhm cacboxyl hnh thnh bng cch chun bng dung dch NaOH.2.2.2.2. Xc nh hm lng tinh bt trong cc ngun nguyn liu t nhin giu tinh bt (ngun C) da trn phng php Bernfeld2.2.2.3. Xc nh hm lng m tng s trong cc ngun nguyn liu t nhin giu protein (ngun N) bng phng php Kjeldahl [18]2.2.3. Phng php vt l

- Xc nh pH ca mi trng nui cy bng my o pH in t- Xc nh hp th quang bng my quang ph2.2.4. Phng php ton hc

- S liu c tnh trung bnh, lch chun, s dng phng php hi quy tuyn tnh ti u ha.3. MC CH V PHM VI NGHIN CU

3.1 Mc ch nghin cu

- Xc nh iu kin ti u chng Aspergillus niger tng hp enzyme pectinesterase l thp v enzyme polygalacturonase l cao.3.2 Phm vi nghin cu

- Chng Aspergillus niger c kh nng sinh tng hp enzyme pectinase ngoi bo phn lp t cc loi qu giu pectine v chng Aspergillus niger trong phng th nghim thuc khoa Ha k thut trng i hc Bch Khoa Nng.- Nghin cu iu kin nui cy nh hng n vic thu nhn ch phm enzyme ca chng Aspergillus niger phn lp c.4. NI DUNG NGHIN CU

4.1. Nghin cu l thuyt

4.1.1. Tng quan v chng Asp.niger- Ngun phn lp- c im, cu to, hnh thi- Kh nng sinh enzyme pectinase4.1.2. Tng quan v enzyme pectinase- Gii thiu chung- Phn loi v tnh cht- Enzyme pectinesterase v polygalacturonase

- Ngun thu nhn pectinase- ng dng ca pectinase4.1.3. Tng quan v qu trnh thu nhn enzyme pectinase t vi sinh vt

- Vi sinh vt c kh nng tng hp enzyme pectinase

- Phng php thu nhn pectinase t vi sinh vt4.1.4 Nhng nghin cu trong v ngoi nc c lin quan n ti.

4.2. Nghin cu thc nghim

4.2.1.Phn lp Aspergillus niger t nguyn liu giu pectinePhn lp nm mc Aspergillus niger t v qu giu pectine, s dng mi trng phn lp Czapek.4.2.2. Kho st kh nng sinh tng hp PE v PG ca A.niger- La chn mi trng.

- Nui cy Aspergillus niger trn mi trng la chn c v xc nh hot lc PE v PG.4.2.3. Nghin cu nh hng ca iu kin nui cy n hot lc enzyme PG v PE sinh tng hp bi Aspergillus niger- nh hng cu pH mi trng

Thc hin thay i pH ca mi trng v tin hnh nui cy theo ch trn.

Cc gi tr pH ban u ca mi trng c thay i theo cc mc: 3.5 6.5. - nh hng ca hm lng c cht b sung vo mi trng nui cyC cht c s dng l ngun pectine (pectine hoc bt v cam hoc chit xut v cam).

Thc hin thay i hm lng pectine b sung vo mi trng v tin hnh nui cy.

Cc hm lng pectine ban u (tnh theo pectine) nh sau: 5 20 g/l.- nh hng ca thi gian nui cy B tr th nghim nui cy vi pH, nhit thch hp v ly mu xc nh hot PG v PE.Cc khong thi gian tin hnh ly mu l: 24h 120h.4.2.4. Ti u ha cc iu kin nui cy PG cao v PE thpThit k th nghim vi cc gi tr ca pH, thi gian ln men v hm lng pectine b sung ti u ha qu trnh tng hp PE v PG bi Aspergillus niger, s dng quy hoch thc nghim, ti u ha hm a mc tiu.4.2.5. Phn tch ch phm enzyme bng phng php in di- Chit tch enzyme t ch phm enzyme th.

- Phn tch enzyme bng phng php in di.4.3. Kt lun:- Xc nh c mi trng nui cy c s dng ngun nguyn liu thch hp chng Asp.niger c kh nng sinh tng hp pectinase ngoi bo cao;

- Xc nh c iu kin nui cy ti u: nhit , pH, thi gian nui cy cho qu trnh sinh tng hp enzyme PE thp v PG cao.5. D KIN TIN NGHIN CU

- T 4/12/2010 n 18/01/2011: Tham kho ti liu, la chn ti, hon thnh cng chi tit sau khi thng qua gio vin hng dn; chun b v bo v cng.

- T 18/01/2010 n 30/01/2011: Tm kim tham kho ti liu, chun b trang thit b, ha cht, nguyn vt liu tin hnh th nghim.

- T 14/02/2010 n 30/06/2011: Trin khai th nghim ti phng th nghim vi sinh khoa Ha, trng i hc Bch khoa Nng. Kt hp vit lun vn: tng quan ti liu kt hp bin lun nhng kt qu thu c trong tng th nghim.- T 01/07/2011 n /08/2011: Hon thnh bn vit lun vn v thng qua gio vin hng dn.

- Bo v lun vn.

6. CHUN B HO CHT V PHNG TIN NGHIN CU

6.1 a im nghin cu

- Phng th nghim vi sinh khoa Ha k thut, trng i hc Bch khoa Nng.

6.2 Ha cht

- Pepton, Aga, pectine, acid polygalacturonic, acid 3,5 -dinitrosalisilic do hng Merk sn xut.

- Cc ha cht v c khc do Trung quc sn xut.6.3 My mc thit b

- T nui cy vi sinh vt c lc (Orbital Incubator S150).- My li tm lnh tc cao (HIMAC CR22G).- Ni cch thy (OSL 200).- My o quang ph (UV/VIS).- My o pH in t (HANA).- T m (WTB).V mt s thit b thng dng ca phng th nghim.

TI LIU THAM KHO

Ting Vit

[1]. Hunh Ngc Oanh, Trn Ngc Hng, Thu nhn enzyme pectinase t asp.niger - tinh sch bng phng php lc gel & lc mng, Tp ch pht trin Khoa hc & Cng ngh, tp 11, s 08 2008.[2] Phm Th Trn Chu, Phan Tun Ngha, 2006, Cng ngh sinh hc, Tp 3 - Enzyme v ng dng, NXB Gio dc.[3] Trn Th Thanh Thun, Nguyn c Lng, Nghin cu enzyme cellulase v pectinase t chng Trichoderma viride v Aspergillus niger nhm x l nhanh v c ph, Tp ch pht trin Khoa hc & Cng ngh, tp 12, s 13 2009.Ting Anh[4] Aurora Martnez-Trujillo, Juan S. Aranda, Guillermo Aguilar-Osorio, Kinetic study on inducibility of polygalacturonases from Aspergillus flavipes FP-500, Electronic Journal of Biotechnology ISSN: 0717-3458 Vol.11 No.4, Issue of October 15, 2008

[5] Evrim Takn, Eva Stratilov, Polygalacturonases Produced Under Solid State and Submerged Fermentation Conditions by Two Strains of Aspergillus foetidus, Turkish Journal of BiochemistryTurk J Biochem, 2008; 33 (4) ; 190196.

[6] Gail Lorenz Miller, Use of DinitrosaIicyIic Acid Reagent for Determination of Reducing Sugar, Analytical Chemistry vol. 31, no. 3, march 1959.[7] H.-D. Belitz, W.Grosch, P. Schieberle, Food Chemistry, Springer Verlag Berlin Heidelberg 2009.[8] Mara A. Martos, Francisco Martinez Vazquez, Fernando O. Benassi and Roque A.Hours, Production of Pectinases by A. niger: Influence of Fermentation Conditions, Brazilian archives of biology and technology, Vol.52, n. 3: pp.567-572, May-June 2009.[9] M. Motallebi, H. Afshari Azad and M.R. Zamani, Polygalacturonase Production by clerotinia Sclerotiorum, Causal Agent of Canola Stem Rot: Parameter Optimization Using Taguchi Approach, World Applied Sciences Journal 3 (1): 96-101, 2008, ISSN 1818-4952

[10] R R Siva Kiran, Rajesh Konduri, G H Rao, G M Madhu, Statistical optimization of endo-polygalacturonase production by overproducing mutants of Aspergillus niger in solid-state fermentation, J Biochem Tech (2010) 2(2):154-157.

[11] Vivek Rangarajan, M. Rajasekharan, R. Ravichandran, K. Sriganesh and V. Vaitheeswaran, Pectinase Production from Orange Peel Extract and Dried Orange Peel Solid as Substrates Using Aspergillus niger, International Journal of Biotechnology and Biochemistry ISSN 0973-2691, Volume 6, Number 3 (2010) pp. 445453.Website:

[12] http://www-saps.plantsci.cam.ac.uk/osmoweb/pectinase.htm(22/12)[13] http://www-saps.plantsci.cam.ac.uk/osmoweb/polygase.htm , 22/12/2010[14] http://download399.mediafire.com/pl2nnv4ku6qg/znmbjywcm2m/

UNG+DUNG+ENZIM+PECTINASE.zip, 24/12/2010[15] http://d.violet.vn/download.php?id=1216070&path=%2Fuploads%2Fresources%2F562%2F1216070%2F%2Fdien_di.doc&file=dien+di&user=1157195, 25/12/2010[16] http://www.mdi.vn/viewer.print.asp?aid=202&l=VN , 28/12/2010[17] http://www.vnulib.edu.vn:8000/dspace/handle/123456789/3489, 04/01/2011[18] http://www2.hcmuaf.edu.vn/contents.php?ur=mnam&ids=1999, 02/01/2011NGI HNG DN KHOA HC

PGS. TS TRN TH XHC VIN THC HIN

L TH THU TRANG

B GIO DC V O TO

TRNG I HC BCH KHOA NNG

KHOA HA K THUT

CNG NGHIN CU LUN VN THC S K THUT

TN TI:

NGHIN CU KH NNG TNG HP PECTINESTERASE V POLYGALACTURONASE CA ASPERGILLUS NIGER

Chuyn ngnh: CNG NGH THC PHM V UNG

M NGNH: 60.54.02

HVTH: L TH THU TRANG

HDKH: PGS.TS. TRN TH X

KHA: K20.CTP.N

Nng - 2011

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