Enzym Keratinaza Phân Hủy Lông Gia Cầm

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Enzym Keratinaza Phân Hủy Lông Gia Cầm

Transcript of Enzym Keratinaza Phân Hủy Lông Gia Cầm

i hc Khoa hc T nhin_ HQGHN ----------

BI TIU LUNng dng enzym keratinaza trong phn hy lng gia cm lm thc n chn nui Ging vin : Nguyn Th HNhm 7 K57 CNKTMTDanh sch thnh vin:1. Phm Th Liu2. inh Th Diu Linh3. Hunh Th Phng Linh

Ni DungI. Cht thi lng gia cm1.1 Thc trng cht thi lng gia cm1.2 Keratin1.2.1 Ngun gc Keratin 1.2.2 Cu trc Keratin1.2.3 Tnh cht keratinII. Enzym Keratinaza2.1 c tnh enzyme Keratinaza2.2 Ngun gc enzyme keratinazaIII. ng dng enzyme keratinaza trong phn hy lng gia cm3.1 C ch phn hy keratin3.2 Cc yu t nh hng n hiu sut phn hy3.3 Sn xut thc n chn nuiIV. Kt lunV. Ti liu tham kho

I.Cht Thi Lng Gia Cm1.1 Thc trng rc thi lng gia cm Pht trin ngnh chn nui l mt phn quan trng trong gii quyt vn lng thc, thc phm trn th gii. Qu trnh ny ng thi to ra lng ln rc thi lng v. Mi nm trn th gii c vi triu tn lng v c to ra t ngnh ch bin gia cm v t l tng hng nm l khong 4,5%. y l cht thi rt kh x l do thnh phn chnh l keratin - mt loi protein c kh nng chng li cc tc nhn phn hy cao, thi gian lng v t phn hy hon ton trong t nhin l t 5 7 nm. Ph phm lng gia sc gia cm thng c x l bng phng php chn lp hoc t chy, thm ch thi trc tip ra mi trng, gy nhim nghim trng cho mi trng t, nc, khng kh ( hnh 1) Hnh 1. Cht thi lng gia cm khng c thu gom x lX l lng v khng ng quy nh gy nh hng nghim trng n sc khe con ngi v mi trng ( hnh 2 ) Hnh 2 .X l, ch bin lng v khng ng quy nh Do bn cht ca lng gia cm l protein nn nu c x l ph hp th c th tr thnh ngun protein b sung hiu qu vo thc n chn nui, em li hiu qu cao v kinh t v c th gii quyt cc vn lin quan n mi trng. Tuy nhin hin nay cc c s sn xut thng p dng cng ngh hin i sn xut bt lng thng mi. Qu trnh ny tn rt nhiu nng lng v cng khng thy phn hon ton c lng v. Nhng phng php ny ph hy amino acid lm gim cht lng v t l tiu ha Protein.Bng 1: Thnh phn t l ca protein v acid amin trong lng v

( ngun latshaw et al . 1994) Vic s dng enzyme thy phn l phng n hiu qu, khng tn nng lng m hiu sut thy phn gn nh hon ton. Trong nhng nm gn y, cc nh khoa hc trn th gii c nhiu nghin cu v cc vi sinh vt c hot tnh keratinaza, v c im v ng dng ca chng, bc u phc v cho vic phn hy ph phm lng dng lm thc n chn nui v gii quyt c nhiu vn mi trng.

1.2 Keratin1.2.2 Ngun gc Keratin t nhin c to thnh t cc t bo sng ca c th. Trong t nhin keratin l thnh phn chnh cu to nn cc cu trc nh lng, tc, mng, guc, sng, da, biu m ca t bo ng vt c xng sng Ty thuc vo loi ging v tui ca ng vt m t l lng trn trng lng c th c s khc nhau. i vi g trng thnh lng v chim 5 7 % khi lng c th. i vi gia sc nh ln th t l ny l 0,5 0,8 % khi lng c th. Keratin chim n 90% khi lng lng v nn y c xem nh l ngun protein tim nng thay th cho mt s ngun protein khc b sung vo thnh phn thc n chn nui. 1.2.3 Cu trc ca keratin Keratin l nhm cc protein c cu trc si c trong t bo biu m ca ng vt c xng sng v l thnh phn ch yu cu to nn cc thnh phn ph nh mng, tc, lng, Keratin cc loi ng vt c xng sng khc nhau c trnh t acid amin v cu trc c bn tng t nhau. Trnh t acid amin quyt nh n cc lin kt trong phn t v tnh cht ca nhng cu trc bc cao hn, cng nh nh hng n cc lin kt trong phn t keratin. Cc chui acid amin ny c cun cht, dng xon ( keratin) hoc dng phin ( keratin ) v gp np to thnh cu trc ba chiu. ( hnh 3) Hnh 3 : cu to hnh hc ca keratin v keratin Trong s cc acid min to nn cc phn t keratin th cyscein l ph bin nht (c th chim ti 24%).Trong cu trc ca acid amin cyscein c cha lu hunh c kh nng to s lin kt cho cht ch nh vo nhng cu ni disunfua. Theo hm lng lu hunh Keratin c phn thnh hai nhm chnh da theo . Keratin cng: hin din nhiu tc, mng, guc, vi hm lng cu ni disunfua cao. keratin mm: cc cu ni disunfua t hn v ch yu da, m. 1.2.4 Tnh cht ca keratin Keratin l protein rt bn, rt kh ha tan v b phn hy bi cc proteaza thng thng nh : trypsin, papain, pepsin. Keratin c th ha tan hon ton trong cc dung dch c cha cht bin tnh nh ur. Keratin trong dung dch c th lp rp li si trung gian. Hu ht cc t bo cha nhiu keratin m chng ta gp l t bo cht v c th c rng ra hoc b cc t bo mi y ln. Nu cc t bo cht ny c lu gi trong tnh trng tt, chng s c tc dng nh mt lp cch in, cch nhit, khng thm nc, bo v cc t bo pha di.II. Enzym Keratinaza2.1 c Tnh Ca Keratinaza Keratinaza c tn IUB l EC 3.4.99. Trng lng phn t 33kDa. Keratinaza t vi sinh vt c pH ti u nm trong khong t trung tnh n kim (6-9) v l loi enzyme a nhit, nhit ti u t 30oC n 80oC, c khi t ti 100oC. Keratinaza l loi enzyme c kh nng phn hy c cht cha Keratin trong t nhin. Keratinaza ch yu c xp vo nhm proteaza serin do c n 97% cu trc ging vi cu trc ca proteaza serin v cng b c ch bi cc cht c ch proteaza serin. Hnh 4 : enzyme keratinaza Tuy Keratin l mt dng protein kh b phn hy, nhng thc t ngoi t nhin cc dng c cht cha Keratin nh lng, mng, sngvn b phn hy. iu ny c c l do hot ng ca cc vi sinh vt (vi khun, x khun, nm mc) c kh nng sinh ra enzym Keratinaza. Keratinase ch yu tn cng vo cc lin kt disulfide (S-S), lm suy gim cc protein dng si fibrin, elastin, collagen v si protein khc.Tuy nhin kh nng to ra enzym ny ca vi sinh vt ph thuc vo nhiu yu t nh chng vi sinh vt, ngun c cht v c iu kin ca mi trng. y c xem nh ngun enzym quan trng c kh nng ng dng vo nhiu lnh vc khc nhau nh cng nghip da, phn bn, thc n chn nui, y dc

2.2 Ngun Gc Keratinaza l mt dng protease rt ph bin trong th gii vi sinh vt. Vi sinh vt tng hp Keratinaza c phn lp t nhiu v tr a l khc nhau, t t Nam cc n sui nc nng, k c iu kin mi trng k kh v hiu kh. n nay Keratinaza c nghin cu ch yu c ngun gc t vi khun, c bit l t chi Bacillus. ( hnh 5 ) Vi khun Bacillus phn b rng trong t nhin, nht l trong t. Chng tham gia tch cc vo s phn hy vt cht hu c nh kh nng sinh nhiu loi enzyme ngoi bo. y l nhng vi khun hnh que, Gram dng, sinh trng hiu kh hoc k kh khng bt buc v hnh thnh ni bo t Hnh 5: vi khun bacillus Hnh 6: nm Chrysosporium Trong s cc loi thuc chi Bacillus th B.licheniformis v B.subtilis c nghin cu l c kh nng thy phn Keratin tt. B.licheniformis l vi khun Gram dng, c tm thy nhiu trong t, nhit tng trng ti u khong 30oC, sinh enzyme ti a 37oC v c kh nng sinh bo t mi trng khc nghit. B.subtilis l trc khun Gram dng, hiu kh ty tin, sinh ni bo t Ngoi vi khun th cn mt s nhm vi sinh vt c kh nng sinh ra enzyme Keratinaza. Nhm vi khun: vi khun Gram dng c kh nng phn hy Keratin bao gm Lysobacter, Kocurica, Nesternokia v mt vi dng Gram m nh Vibrio, Xanthomonas, Stenotrophomonas Nhm x khun ch yu l nhm Streptomyces. Nhm nm: Chrysosporium ( hnh 6) , Fusarium, Geomyces, Monodictys, UrocladiumIII. ng Dng Enzym Keratinaza Trong Phn Hy Lng Gia Cm3.1. C Ch Phn Hy Keratinaza c trong t bo vi khun s b gy cc cu ni disulfide trong cu trc ca keratin, to thnh cc chui protein c cu trc n gin hn, h tr cho qu trnh phn hy ca enzyme ngoi bo. Sn phm cui cng ca qu trnh phn hy bao gm peptide mch ngn c kh nng ha tan v cc axit amin. Nh vy qu trnh phn hy keratin bao gm hai bc l ph hy cc cu ni disulfide v phn hy chui protein Disulphide bonds NH2 NH2 CH2 - S S - CH2 CH2 S- S- - CH2NH CO NH CO CO -----------------HN CO NHR hydrogen bonds R t0, H+/OH R R NH CO + E NH + COOC NH CO NH NH3+ ------ -OOC NH3+ -OOCNH ion-ion interactions CO NH CO CO HN CO NHR R R R t0,enzym ,H+ +H2O NH2-CH-COOH + NH2-CH-COOH + . + peptide mch ngn R CH- SH 3.2 Cc Yu T nh Hng n Qu Trnh Phn Hy Lng3.2.1 nh hng ca nhit v pH Nhit v PH l 2 yu t nh hng rt ln n s tn ti v pht trin ca vi sinh vt. Nhit qu thp hoc qu cao s lm c ch qu trnh trao i cht, tiu dit t bo vi sinh vt.( Hnh 8). Nng H+ c trong mi trng lm thay i tnh thm ca t bo, nh hng n h enzyme trn thnh t bo cng nh cc enzyme ngoi bo t, lm nh hng n kh nng trao i cht v pht trin ca t bo vsv. ( Ngun: G.-T. Park, H.-J. Son et al.2007) Hnh 8. nh hng ca nhit n mt v hot ng ca enzyme kerstinza

( Ngun: G.-T. Park, H.-J. Son et al.2007)Hnh 9. nh hng ca pH n m