I HC QUC GIA THNH PH H CH MINHTRNG I HC KHOA HC T NHIN

CNG NGH SINH HCVI SINH VT

Ging vin: TS. Nguyn Th Bch Hu ti: Cng ngh sinh hc ca acid citric sn xut Thnh vin_Nhm 4:Nguyn Th Xun Diu1118061V ng Phng Lan1118217Hong Th Ca Ly1118247V Th Khnh Ngn1118280Nguyn Tn Anh Nhi111831420/10/2014

Mc lcI HC QUC GIA THNH PH H CH MINH1I.Axit citric31)Gii thiu32)Thng tin tng qut3- Tn theo IUPAC: 2-hydroxypropane-1,2,3-tricarboxylic acid33)Tnh cht34)Lch s tm ra45)Sn xut46)ng dng4II.Aspergillus niger51)Gii thiu A. niger52) C s l thuyt ca qu trnh ln men acid citric53)Mi trng6III.Sn xut acid citric91)Cc phng php sn xut acid citric9a.Phng php ln men b mt9b.Phng php ln men chm112)Cng ngh sn xut acid citric bng phng php ln men chm s dng nm mc Aspergillus niger123)Cc yu t quyt nh n qu trnh sn xut acid citric14IV.Tnh hnh sn xut acid citric hin nay15V.Hng tng lai trong sn xut acid citric15

I. Axit citricGii thiu Axt citric l mt axt hu c thuc loi yu v n thng c tm thy trong cc loi tri cy thuc h cam qut. N l cht bo qun thc phm t nhin v thng c thm vo thc n v ung lm v chua. lnh vc ha sinh th axt citric ng mt vai tr trung gian v cng quan trng trong qu trnh trao i cht xy ra trong cc vt th sng. Ngoi ra axt citric cn ng vai tr nh l mt cht ty ra, an ton i vimi trngv ng thi l tc nhn chng oxy ha. Axt citric c mt trong nhiu loi tri cy v rau qu nhng trong tri chanh th hm lng ca n c tm thy nhiu nht, theo c tnh axt citric chim khong 8% khi lng kh ca tri chanh.Thng tin tng qut- Tn theo IUPAC: 2-hydroxypropane-1,2,3-tricarboxylic acid Tn thng thng: axit chanh Cng thc phn t: C6H8O7 Cng thc cu to:

Khi lng phn t: 192.13 g/mol C dng: tinh th mu trngTnh cht Tnh axt ca axit citric l do nh hng ca nhm carboxyl -COOH, mi nhm carboxyl c th cho i mt proton to thnh ion citrat. Cc mui citrat dng lm dung dch m rt tt hn ch s thay i pH ca cc dung dch axt. Cc ion citrat kt hp vi cc ion kim loi to thnh mui, ph bin nht l mui canxi citrat dng lm cht bo qun v gi v cho thc phm. Bn cnh ion citrat c th kt hp vi cc ion kim loi to thnh cc phc dng lm cht bo qun v lm mm nc. nhit phng th axt citric tn ti dng tinh th mu trng dng bt hoc dng khan hay l dng monohydrat c cha mt phn t nc trong mi phn t ca axt citric. Dng khan thu c khi axt citric kt tinh trong nc nng, tri li dng monohydrat li kt tinh trong nc lnh. nhit trn 74oC dng monohydrat s chuyn sang dng khan. V mtha hcth axt citric cng c tnh cht tng t nh cc axt carboxylic khc. Khi nhit trn 175oC th n phn hy to thnh CO2v nc.Lch s tm ra Vo th k th 8 nh gi kim thut Jabir Ibn Hayyan ngi Iran pht hin ra axt citric. Cc hc gi chu u thi trung c cng bit v axt t nhin trong chanh, nhng kin thc s b v axt ny cng c ghi nhn vo th k XIII. Axt Citric c nhha hcngi Thy S tch c vo nm 1784, ng kt tinh c axt citric t nc chanh p. Nm 1860 ngnh cng nghip nc p tri cy ca a cng trnh sn xut axt citric vo hot ng. Nm 1893 C. Wehmer pht hin ra rng nm mc (Penicillium) cng c th to nn axt citric t ng. Sn xut axt citric theo kiu vi sinh ny khng c a vo sn xut cng nghip cho n th chin th I, do cc xut khu nc hoa qu ca bc b. Vo nm 1917 nhha hcthc phm James Currie ngi M pht hin ra rng nm mc hnh si (Aspergillus niger) c th dng sn xut axt citric rt hiu qu. Hai nm sau tp on dc phm Pfizer ng dng k thut ny vo sn xut axt citric theo qui m cng nghip.Sn xut K thut m ngy nay ngi ta vn dng trong cng nghip sn xut axt citric l nui nm si trn ng n, sau lc nm mc ra khi dung dch v axt citric c tch bng cch cho kt ta vi nc vi to thnh canxi citrat, sau kt ta c x l bng axt sulfuric. Ngoi ra axt citric cn c tch t sn phm ln men ca nc lo bng cch dng mt dung dch hydrocacbon ca mt baz hu c Trilaurylamin chit. Sau tch dung dch hu c bng nc.ng dng Vi vai tr l mt cht ph gia thc phm, axt citric c dng lm gia v, cht bo qun thc phm v ung, c bit l nc gii kht, n mang m s E330. Mui citrat ca nhiu kim loi c dng vn chuyn cc khong cht trong cc thnh phn ca cht n king vo c th. Tnh cht m ca cc phc citrat c dng hiu chnh pH ca cht ty ra v dc phm. Citric axt c kh nng to phc vi nhiu kim loi c tc dng tch cc trong x phng v cht ty ra. Bng cch phc ha cc kim loi trong nc cng, cc phc ny cho php cc cht ty ra to nhiu bt hn v ty sch hn m khng cn lm mm nc trc. Bn cnh axt citric cn dng sn xut cc cht trao i ion dng lm mm nc bng cch tch ion kim loi ra khi phc citrat. Axt citric c dng trong cng nghsinh hcv cng nghip dc phm lm sch ng dn thay v phi dng axt nitric. Citric axt l mt trong nhngha chtcn thit cho qu trnh tng hp Hexametylen triperoxit diamin (HMDT) l mt cht d pht n ging Axeton peroxit, nhy vi nhit v ma st. mt s nc nu bn mua mt s lng ln axt citric bn s b lit k vo s en ca cc m mu khng b. Axt citric cng c cho vo thnh phn ca kem gi cc git cht bo tch bit. Ngoi ra n cng c thm vo nc p chanh ti. Citric axit c coi l an ton s dng cho thc phm cc quc gia trn th gii. N l mt thnh phn t nhin c mt hu ht cc vt th sng, lng d axt citric s b chuyn ha v o thi khi c th. iu th v l mc d axt citric c mt khp ni trong c th nhng vn c mt vi trng hp mn cm vi axt citric. Tuy nhin nhng trng hp ny rt him v ngi ta thng gi l phn ng gi v ca c th. Axt citric kh c th lm kch thch da v mt do nn mc o bo h khi tip xc vi axt ny.II. Aspergillus niger1) Gii thiu A. niger C nhiu loi nm mc c kh nng oxy ha gluxit thnh axit citric nh Rhizopus, Aspergillus, Penicillium. Trong quan trng nht l Aspergillus niger. Aspergillus niger l mt loi nm si v mt trong nhng loi ph bin nht ca chi Aspergillus c nhiu cng dng trong cng ngh sinh hc, nhit ti u 35 370C, pH t 1,4 - 9. N gy ra mt cn bnh c gi l nm mc en trn mt s loi tri cy v rau qu nh nho, hnh ty, u phng, v l mt cht gy nhim ph bin ca thc phm. Aspergillus niger l vi sinh vt hiu kh pht trin trn cc cht hu c, do n c th c tm thy gn nh khp mi ni trong mi trng c cha t. Ngoi ra, n c tm thy trong cht thi, nguyn liu thc vt phn hy v phn hu c trong mi trng ngoi tri. Mi trng trong nh to ra mt mi trng sng tt cho s pht trin ca nm mc. Chng hn nh trong cc lnh vc h gia nh thng thng, trn cc bc tng trong phng tm hoc cc khu vc khu vc khc c m cao.A.nigerc nui sn xut nhiu cht trong cng nghip, trong c axit citric2) C s l thuyt ca qu trnh ln men acid citric Trong qu trnh ny glucose c chuyn ho thnh axit pyruvic theo con ng EMP (Embden-Mayerhof-Parnas), sau axit pyruvic tip tc chuyn ho thnh axit citric. Phng trnh tng qut ca qu trnh ny nh sau: 2C6H12O6 + 3 O2 6C6H8O7 + 4H2OC ch ca s chuyn ho ny c th c biu din nh sau: ng C6H12O6 thu phn thnh acid pyruvic (CH3COCOOH) CH3COCOOH + CO2 HOOCCH2COCOOH (Acid oxaloacetic) HOOCCH2COCOOH + CH3COOH CH2COOHCOHCOOHCH2COOH(Acid citric)3) Mi trng a s cc quy trnh cng nghip hin nay s dng ngun c cht l r ng. Nhng d c s dng ngun c cht nh th no th ngi ta vn cn phi ch y n hai yu t quan trng l gi thnh v cc yu t cn chun b cung cp iu kin thun li nht cho vi sinh vt ln men. Ngun c cht c bn c dng trong cc quy trnh ln men ni l mt r ng ma hoc mt r c ci ng. Cn i vi cc quy trnh ln men ni th ngun c cht c th c s dng khng ch l mt r ng m cn l nhng c cht c tinh khit cao hn nh glucose tinh khit, ng th hoc ng tinh, nc p ma v c ci ng c c. S dng cc ngun c cht tinh khit nh trn c th gip lm nng nng sut hoc gip gim thi gian nui cy.Di y l bn nng cc cht trong nui cy Aspergillus niger nhm ln men acid citric:Thnh phnKhong gi trGi tr chung

Sucrose/Glucose125-225 kg/m3180 kg/m3

NH4NO3 (hoc mui NH4+ khc)0.5-3.5 kg/m31.5 kg/m3

KH2PO40.5-2.0 kg/m30.5 kg/m3

MgSO4.7H2O0.1-2.0 kg/m30.25 kg/m3

Fe++2-1300 mg/m3 hn ch lng cht thi rn to ra => gim thiu chi ph x l.

Ti liu tham khohttp://www.authorstream.com/Presentation/chweetpia-1395191-citric-acid/http://baigiang.violet.vn/present/show/entry_id/8212525http://luanvan.net.vn/luan-van/quy-trinh-len-men-acid-citric-tu-aspergillus-niger-58815/Cng ngh sinh hc tp 5 Cng ngh vi sinh v mi trng GS.TS. Phm Vn Ty TS. V Nguyn ThnhC s cng ngh sinh hc tp 4 Cng ngh vi sinh L Vn Hng, Nguyn Vn Cch.Citric acid production - Marin Berovic, Matic Legisa