Tài liệu Vi sinh vật bệnh truyền nhiễm vật nuôi

N G U Y iN BA HIEN (Chu b ien ) N G U Y i N QUOC DOANH - PHAM SY LANG - NGUYEN TH| KIM TH AN H C H U O iN H t6 i VI SINH VAT BENH TRUYEN NHlilM VAT NUOI • • (T d i b a n la n t h u n h a t) NHA XUAT BAN GIAO DUC VIET NAM Cong ty Co phan sach Dai hpc - Day nghe - Nha xuat ban Giao due Viet N.am giur quyen cong bo tac pham. 04 - 2009/CXB/495 - 2 1 17/GD Ma so : 7K747y9 - DAI LOI NOI DAU Vi sinh vat - Benh truyen nhiem vat nuoi du’o’c bien soan nham cung cap 7 mot so tai lieu de cac sinh vien Cao dang, Trung cap chuyen nghiep chuyen nganh Chan nuoi - Thu y, giao vien va hoc sinh pho thong trong qua trinh day va hoc m on cong nghe (phan Nong - Lam - Ngtf nghiep), sinh vien khoa Sinh Kv thuat Nong nghiep cac trirdng Dai hoc, Cao dSng... co the’ dung de tham khao khi giang day ly thuyet cung nhir thirc hanh. Cac tac gia tham gia bien soan difdc phan cong nhu* sau: Cac chifdng 1, II, III, V, VI, VII do tac gia N guyen Ba Hien bien soan. Chitctng IV do cac tac gia N guyen Thi Kim Thanh va Chu Dinh Tdi bien soan. Chifdng VIII do cac tac gia Pham Sy Lang va Nguyen Quoc Doanh bien soan. Trong qua trinh bien soan chung toi da co gang gidi thieu, bd sung nil img kien thitc, noi dung can thiet va hien dai dira tren nhimg thanh tiru cua khoa hoc Thii v va nhimg kinh nghiem thirc ti£n dirdc tong ket trong nganh. Vi day la lan dau tien bien soan mot tai lieu tham khao chung cho nhieu doi tirdng sir dung nen chSc chan khong the tranh khoi nhirng thieu sot. Chiing toi rat mong nhan dirdc nhung y kien dong gop cua cac ban dong nghiep va ban doc trong qua trinh sir dung tai lieu nay de cuon sanh ngay cang hoan thien hern. Moi y kien dong gop xin giii ve Cong ty cd phAn sach Dai hoc - Day nghe, Nha xuat ban Giao due, 25 Han Thuyen, Ha Noi. Dien thoai (04) 8264974. Chiing toi xin chan thanh cam c?n! Cac tac gia 3 MUC LUC Trang Loi noi dau 3 PHAN THL/ NHAT. OAI C lfO N G C h u o n g 1. Dai cuong ve vi khuan va virus I. Cau tao va sinh ly cua vi khuain 7 7 II. V irus 24 III. A nh huong cua ngoai canh den vi sinh vat 35 C h u o n g 2. P h u on g thuc gay benh cua vi sinh vat va kha nang m ien dich ciia co the d ong vat 45 I. NhiSm trung va phuong thuc gay benh cua vi sinh vat 45 II. K ha nang mi£n dich cua co the 49 Chirong 3. Dai cu on g ve benh truyen nhiem 69 I. Cac thoi ky tien trien cua benh truyen nhidm - cac the benh 69 II. Q ua trinh sinh dich 72 III. Phong va chong dich benh truyen nhiem 78 PHAN THU HAI. CHUYEN KHOA C h u o n g 4. Benh truyen nhiem chung cho nhieu loai vat nuoi 90 Benh nhiet than 90 Benh dai 97 Benh lao 4 Benh xoan khuain 109 Benh say thai truyen nhi6m 115 Benh uon van 121 Chirang 5. Benh truyen nhiem a trau, bo 126 Benh la m om long m o ng 126 Benh bo dien 133 Benh tu huyet trung trau, bd 139 C h u on g 6. Benh a loai lgn 145 Benh dich ta lgn 145 Benh dich ta lgn chau Phi 153 Hoi chirng roi loan ho hap va sinh san d lgn 157 Benh tu huyet trung lgn 165 Benh dong dau lgn 170 Benh phd thirang han lgn 176 Benh phu thung d lgn con 181 Benh suydn lgn 186 C huong 7. Benh truyen nhiem a gia cam 192 Benh Newcastle 192 Benh cum gia cam 202 Benh Gumboro 208 Benh tu huyet trung gia cam 214 Benh thuang han ga 218 Benh viem dudng ho hap man tmh d ga 223 Benh dich ta vit 230 Benh viem gan do virus cua vit 238 Phan thuc hanh Bdi I Bao quan, sir dung kinh hien vi de quan sat vi sinh vat - phuang phap lam tieu ban Bai 2 Nuoi cay vi khuan, virus - vacxin va phuang phap sir dung vacxin 244 247 Bdi 3 Phuang phap md kham dong vat thi nghiem, lay benh pham trong chan doan, xet nghiem, mot sd phuang phap tieu doc, sat trung 250 5 Bai 4. Benh truydn nhidm a loai lan 252 Bai 5. Benh truydn nhidm a gia c£m 253 Bai 6. Tiem phong bdnh cho Ion 255 C huong 8. Benh truyen nhi6m cho, meo Benh sai s6't cua cho 257 Benh viem ruot do Parvovirus a cho 261 Benh vi6m gan truydn nhidm a cho 265 Benh ia chay do Parvovirus a meo 269 Ky thuat thuc hanh trong didu tri 272 Tai lieu tham khao 6 257 277 P h a n th iV n h a t OAI CUONG ■ Chuong 1 OAI CUONG VE VI KHUAN VA VIRUS I. C A U TAO VA SINH LY CUA VI KHUAN 1.1. Khai niem Vi khudn (Bacteria) la nhung vi sinh vat ma ca th i chi g6m mot te bao, khong co mang nhan (Prokaryote), thudng co kich thudc dai'tir 1 - 10p.m, rong 0,2 - 1,5p.m. Vi khudn co hinh thai rieng, dac tmh sinh hoc rieng, da so song hoai sinh trong tir nhidn, mot so co kha nang tiet khang sinh, mot s6 co kha nang gay benh cho ngudi va dong vat. Co the nuoi c£y vi khuan trong cac moi truang nhan tao va quan sat dugc hinh thai cua chung duai kmh hien vi quang hoc thong thuang. 1.2. Hinh thai co ban cua vi khudn Vi khuan co hinh thai nhat dinh, hinh thai nay do mang vi khuan quyet dinh. Nhin b i ngoai, ngirdi ta chia vi khudn lam 5 loai hinh chinh: c£u khudn, true khudn, cau trirc khudn, xoAn khudn va phay khudn. 7.2.7. C au k h u d n (coccus) C iu khuan la loai vi khudn phan ldn co hinh c£u nhung co the co hinh bSu due, hinh ngon nen. Dirdng kinh cua vi khuan thay doi trong khoang 0,5 - 1pm. Tuy theo loi phAn chia, tuy vi tri cua mat phAng phan cat va dac tinh ndi nhau hoac dmh lai vdi nhau sau khi phAn chia ma cau khudn lai chia thanh cac gidng sau: a) Vi cau khudn (M icrococcus) La loai cau khuan dung rieng re timg te bao m6t, loai nay thudng sdng hoai sinh trong dat, nude va khdng khi. b) Song can khudn (Diplococcus) Khi phAn chia, c iu khuan phan cAt theo mot mat phAng xac dinh r6i dm h vdi nhau thanh tung doi mot, da so song cau song hoai sinh trong tu nhien, cd mot so loai gAy benh nhir lau cau khuan (Neisseria gonorrhoeiae), phe cau khuan (Diplococcus pneumonia) hay nao m6 cSu khuan Neisseria meningitidis 7 c) Lien can khuan (Streptococcus) CiUi khuan phan cat theo mot mat ph&ng xac dinh roi dinh lien vai nhau thanh chuoi dai. Nhirng loai dang chu y nhir: liC‘n cau gay mil Streptococcus pyogenes, lien c£u khuan gay benh viem hach truyen nhiem a ngua Streptococcus equi.... cl) Tu cau khuan (Staphylococcus) C&u khuan phan cat theo nhung mat phAng bat ky roi dfnh lai vai nhau thanh timg dam giong nhu hinh chum nho. Da so H inh 1.1. Streptococcus equi tu cau song hoai sinh, mot so gay benh cho dong vat nhu Staphylococcus aureiLs*. 1.2.2. True k h u a n (Bacteria) True khuan la ten chung de chi nhung vi khuan co hinh que, hinh gay. Kich thudc cua true khuain vao khoang 0 ,5 -lx l - 4p.m. Nhung true khuan hay gap thuoc cac giong sau: a) Bacillus La true khuan gram dirong ( + ) \ song hieu khi, sinh nha bao nhung chidu ngang cua nha bao nho hon chieu ngang cua vi khuan nen khi vi khuan mang nha bao se khong bi bien dang. Vi du: Vi khuan gay benh nhiet than (Bacillus anthracis)\ true khuan co kho (Bacillus subtil is). Hinh 1.2. S taphylococcus aureus b) Clostridium La nhung true khuan gram (+), song yem khi, sinh nha bao nhung chieu ngang nha bao lan han than vi khuan nen khi vi khuain mang nha bao se bi bien d6i hinh dang. 17 du: Vi khuan uon van (Clostridium tetani) khi mang nha bao co hinh dui trong, hinh dinh ghim. 1 Viec phan biet 2 loai vi khuan gram (+) va gram (-) do nha vi khuan hoc Christian Gram, ngi/di Dan Mach (1889) da dua ra phifdng phap nhuom, sau nay mang ten ong: phUdng phap nhuom Gram. Bang phudng phap nhuom nay, nhung vi khuan bat mau tim cua thuoc nhuom tim Genxian, tay mau bang con axeton cung khong bi troi la vi khuan gram (+), vi khuan gram (-) khi tay mau bang con axeton mau tim troi di, nhuom mau do Fucxin chung bat mau do goi la vi khuan gram (-). 8 c) B aderuim La nhimg tnrc khuan gram (-), khong sinh nha bao, thirang co long xung quanh than. \7 du: Cac vi khuan dirang ruot nhir Bacterium coli. \ / \ V ^s. / * \ Hinh 1.4. C lo strid iu m tetani Hinh 15- Pasteurella m ultocida 1.2.3. C au true k h u a n (C occobacterium ) La loai vi khuan trung gian gifra cau khuan va tnrc khuan, vi khuan song hieu khu, bat mau gram (-), co hinh tnrng hoac ban due. \ 7 du: Vi khuan gay ra benh tu huyet trung (Pasteurella multocida). 1.2.4. X o a n kh u a n (Spirilium ) Gom tat ca nhung vi khuan co tir hai vong xoan trd len, gram (+), di dong durgc. Tuv cach sap xep ciia cac vong xo&n ma co cac giong sau: a) Barrel ia Vong xoan thira, khong deu nhau va khong co quy tkc. \ 7 du: Xoan khuan gay tang sinh bach cau d ga (Borrelia gallinarum). b ) I reponema Nhieu vong xoan sat nhau, sap xep deu dan, co quy tac. Hinh 1.6. Leptospira 9 Vi du: Xoan khudn gay benh giang m ai (Treponema pallidum). c) Leptospira Vong x oin hai sat nhau, sip xep Ion x6n, 2 d iu thucmg uon cong nhir moc c£u. Vi du: Loai x oin khuan hay gay benh tren cho Leptospira canicola. 7.2.5. Phdy khudn (Vibrio) Phay khuan la ten chung de chi nhtfng vi khuan co hinh que, uon cong len trong giong nhir d&'u phay. V i du: Phay khuan gay benh th6 ta: Vibro cholerae. 1.3. Cau tao te bao vi khuan Te bao vi khuan co nhung tmh chat khac vdi cac te bao dong, thircv&t d ch6: nhan kh6ng co mang, chi la mot nhi6m s ic th i, kh6ng co bo m ay phan bao, lirai n6i hat, ty, lap the va luc lap, khong co chuyen dong dong te bao. Di tir ngoai vao trong, bat cur te bao vi khuan nao cung co cau tao nhu sau: Nguyen sinh chat Mang te bao-^f ^ ^ Mang NSC Riboxom Cach ri Hinh 1.7. Cau true te bao vi khuan 1.3.1. M ang te bao Mang te bao la m6t c&u true bao v£ co chufc nang sau: + Chiu dugc ap s u it th im thau n6i tft' bao. + La cai khung de giu cho t& bao vi k h u in co hinh dang nh£t dinh. Mang te bao bao boc b£n ngoai mang nguy£n sinh ch£t, co c&'u tao hoa hgc phurc tap, la cac hgp chat cao ph&n tir va thay d6i tuy loai nhung thanh phan c a ban bao g6m: glycopeptit, polysaccarit va lipit. 1.3.2. M ang nguyen sinh chat Mang nguyen sinh chat n im phfa trong cua mang te bao, bao bgc khoi nguyen sinh ch£t, co vai tro rit 16n trong hoat d6ng s6ng cua ttf bao. No dam bao 4 chuc nang sau: + Duy tri ap suat tham thau cua te bao. + Dam bao viec chu dong tich luy cac chat dinh duang trong te bao va thai cac san pham trao d6i chat ra ngoai te bao. + La noi xay ra cac qua trinh sinh tdng hop mot so thanh phan ciia te bao va giap mo. + La nai chira mot so enzym va mot so co' quan tu ciia te bao nhu mezoxom, riboxom. Mang nguyen sinh chat co cau tao gom 3 lap: Lap ngoai cung va lap trong cung la 2 lap protein. Giua la lap phospholipit, sir phan bo protein va phospholipit khac nhau a timg vung tren mang da tao ra cac 16 hong, a do co chira mot loai protein dac biet co tac dung van chuyetn thuc an, dugc goi la cac pecmeaza, hay protein van chuyen. 1.3.3. Nguyen sinh chat Nguyen sinh chat la thanh phan chinh cua te bao vi khuan, do la mot khoi keo chua 8 0 - 90% nirac, phan con lai chu yeu la lipoprotein. Trong nguyen sinh chat ciia te bao truang thanh, ngirai ta thay co nhi£u cac co' quan tir nhu mezoxom, riboxom, khong bao, cac hat dir tru, sAc to va cau true nhan. a) Mezoxom La mot the hinh cAu trong giong mot bong bong, nam a vach ngang te bao, chi xuai hien khi te bao phan chia. Vai tro cua no la tao ra vach ngang de chia te bao me thanh hai te bao con. Trong te bao, mezoxom chi co so luoiig bAng mot. b) Riboxom La nhung cau true nho giau ARN chua 40 - 60% la ARN va 60 - 40% la protein, ngoai ra con co mot s6 enzym va mot so khoang chat. Trong te bao, riboxom co so lugng hang van, m6i riboxom co cau tao gom hai tieu phAn khong deu nhau, phan duai Ian hon phan tren nen trong giong hinh con so 8. Riboiom la trung tAm sinh tong hop protein ciia te bao. c) 7ac hai clif in? Gem 4 loai: axit nucleic, lipit, gluxit va cac chat vo ca, no dirge sir dung khi te bao thieu thuc an. cl) Khong bao La mot to chirc co hinh cau, dugc bao boc bai mot lap mang, ben trong chira dAy dich te bao. Khong bao co vai tro quan trong trong viec dieu chinh ap suat tham than ciu te bao va la nai chira nhfmg sail pham trao doi chat bat lgi. 1.2.4. The nhan Thf* nhan la bo phan chua dung bo may di truyen ciia te bao vi khuan, co rat nhi£u ADN. O vi khuan, nhan khong phAn hoa thanh khoi, khong co mang nhAn nen kho qm n sat. Do la mot nhidm sAc the duy nhat, la mot sgi ADN xoAn, co dang vong tron dong kin, neu mo' vong xoAn, sgi ADN dai khoang 1mm. Vi chi co 1 nhiem sic the nen khi phAn chia, vi khuain phAn chia don gian bAng cach cAt doi. Chrc nang cua vi khuain cung giong nhu chuc nAng cua nhAn te bao sinh vat cao cap chu veil gom 2 mat: - Dieu khien viec sinh tong hgp protein. - Di truydn moi tinh ehat cua te bao cho the he sau. 1.3.5. Cac can true khac Ngoai cac cau true ca ban neu tren. d mot sd loai vi khuan con co nhung cau true sau day: a) Gid/) md 0 mot sd loai vi khuan, ben ngoai mang te bao con dirge bao boc bdi mot lap vd, cd klii rat day, goi la giap mo hay vd nhay. Thanh phan hoa hoc cua giap md chu yen la cac hgp chat hydrat cacbon va chira 98% nirdc. Giap mo la nai tich luy chat du tru, giup cho vi khuan dd khang manh ho'n vdi dieu kien song bat lo'i. 0 vi khuan gay benh, giap mo con tang cirdng kha nang gay benh, giup cho vi khuan chong lai sir thuc bao ciia cac te bao thuc bao trong co'the ky chu. Hinh 1.8. Giap mo vi khuan nhiet than h) Nha bao Mot sd loai vi khuan, trong nhung giai doan nhat dinh cd the hinh thanh trong te bao nhung cau true dac biet cd hinh cau, hinh bail due goi la nha bao. Nha bao thudng dugc sinh ra trong nhfrng didu kien kho khan nhu mdi trirdng thieu thirc an, nhiet do. do pH khong thich hgp, mdi trudng tich luy nhidu san phAm trao ddi chat bat lo'i. Hinh 1.9. Nha bao vi khuan nhiet than Vi vay nha bao la mot hinh thuc song tiem sinh ciia vi khuAn, no giup cho vi khuan virot qua duoc nhung dieu kien song bat lgi ciia ngoai canh. Nha bao cd cau tao kha phire tap, dd la mot khoi nguyen sinh chat dong nhat, duoc bao boc bdi nhieu Idp mang cd tac dung ngan chan sir tham than ciia nude va cac chat hoa tan trong nude. Nha bao cd sue dd khang cao ddi vdi cac nhan to vat ly va hoa hoc nhir nhiei do, tia circ tim, ap suat va cac chat sat triing. Trong di£u kien tir nhien, nha bao cd the tdn tai rat lau nen no la nguon lay lan benh nguy hiem ciia nhfrng vi khuan gay benh ma cd sinh nha bao. V i du vi khuan nhiet than, vi khuan uon van,... Sd cfl nha bao cd sire de khang cao va song lau la do cac nguyen nhan sau: 12 - Niroc trong nha bao phan lan d trang thai lien ket do do khong lam hien tinh protein khi tang nhiet do. - Enzym va cac chat hoat dong sinh hoc khac trong nha bao deu t6n tai d dang khong hoat dong. -1 rong nha bao co mot lirong ldn ion Ca2+ va mot loai axit la dipicolinic, protit trong te bao ket hop vdi Ca2+ va axit dipicolinic tao ra mot phirc chat protein dipicolinat canxi cd tmh on dinh cao vdi nhiet do. Khi gap didu kien thuan loi, nha bao hut nirdc, trirang len, mang nut ra va tao thanh vi khuan. Sir nay mam nay lam doi mdi va nang cao sire song cua te bao vi khuan. Nha bao thudng gap d m o t sd giong vi khuan nhir Bacillus, Clostridium . Nha bao cd the ton tai doc lap hoac ton tai ngay trong te bao vi khuan trong te bao, nha bao co the nam d gii'ra te bao, gan dau hoac d mot dau. Vi trf cua nha bao la mot tfnh chat quan trong de phan loai vi khuan. c) Long cua vi khuan Mot sd loai vi khuan cd long d tren than nen cd kha nang di dong mot cach chu dong. Long ciia vi khuan co ban chat la protein va do nhieu sai nho xoan lai vdi nhau tao thanh. Moi long moc ra tir mol hat goc nam d mat trong cua mang nguyen sinh chat. Vi trf va so lirong long thay doi tuy loai vi khuan. Cd vi khuan chi cd mdt long d dau £oi la tien mao. Cd nhidu long d m o t dau goi la chum mao. Cd nhieu ldng moc xung quanh than goi la chu mao. d) Pili Ngoai long, mot sd vi khuan con co tiem mao hay fim briae (yeu td bam dinh), do la nhfrng sai protein rat ngan va manh. Pili la mdt phuang tien giiip cho te bao vi khuan bam chAc len bC; mat ciia co' chat (tlnrc an hoac gia the). 1.4. Sinh ly hoc ciia vi k h u an Sinh ly hoc ciia vi khuan la khoa hoc ve sir dinh dudng, sinh trirdng va cac chirc nang song khac cua vi khuain. Noi dung cu the ciia khoa hoc sinh ly vi khuan la nghien ciru thanh phan hoa hoc, quy luat va c a c h e cua sir dinh dirdng, ho hap, sinh trirdng va phat trien cua vi khuan. / .4.1. T h a n h p h a n hod hoc cua te bao vi kh u a n Phan tich thanh phan hoa hoc ciia te bao vi khuan, ngirdi ta thay rang te bao vi khuan co cau tao chu yeu la nirdc va mot phan vat chat kho. 1.4.1.1. Nude Chiem 70 - 80% khoi liro'ng te bao, ton tai d hai dang: - Nirdc ket hop tham gia vao thanh phan chat keo ciia nguyen sinh chat te bao. - Nude tir do: La dung mdi cho sir song, tham gia vao cac phan irng thuy phan trong te bao. 1.4.1.2. Chat kho Cha'i kho trong te bao chiem tir 15- 25% khoi luong te bao gom: a ) Cac 11git yen td khoang Da lirong nhirCa, Na, K, Fe,... Vi lirgng nhirZn, Co, Mo, Cr,... b) C ar hop chat hiln co' gom cd - Protit chiem 50 - 80% khoi lirgng kho te bao va g6m 2 loai: + Protein: Lit nhfrng protit don gian nhir albumin, globulin do la cac chat dir trfr. + Proteit: Lit nhimg protit phire tap co \'ai tro sinh hoc trong te bao nhir Nucleoproteit, lipoproteit va cac enzym. - Glux.it: Ton tai 6 hai dang: dan gian (oza) va phire tap (ozit) day la thirc an dir trir ciia te bao va tham gia hinh thanh nen giap mo a mot so loai vi khuan. - Lipit: T6n tai diroi dang don gian la cac hat m a dir trir. Dang phire tap la lipoproteit tao len cau true mang nguyen sinh chat te bao. - Enzym: G6m hai loai. + Ngoai enzym: La nhirng enzym vi khuan tiet ra moi truang ngoai, co tac dung thuy phan nhfrng phan tir hfm ca lan thanh nhfrng phan tir nho hon de vi khuan co the hap thu. + Noi enzym: Co trong te bao co tac dung xiic tac sir chuyen hoa trong te bao. - Doc to ciia vi khuan: Trong qua trinh song, mot so loai vi khuan tiet ra moi tnrang hoac tong hgp trong ca the nhimg hop chat hfru c a co tinh doc cao, c6 tac dung dau doc ca the dong vAt, goi la doc to. Doc to ciia vi khuan co hai loai: Loai tiet ra moi tnrang goi la ngoai doc to; mot loai ton tai trong te bao, chi diroc giai phong khi te bao bi pha va goi la noi doc to. 1.4.2. D in h clnong cua vi sinh vat Trong hoat dong song, vi khuAn luon hap thu cac chat dinh dirang tir moi tnrang vao ca the va dao thai cac chat khong a in thiet ra ngoai. Qua trinh nay dirge tlurc hien qua mang te bao chat. Qua trinh dinh dirang chinh la qua trinh hap thu cac chat dinh dirang tir moi tnrang xung quanh vao te bao vi khuan. 1.4.2.1. Nhu cau th u c an ciia vi k h u a n De duy tri sir song, vi khuan can mot lirgng thirc an bAng khoi lirong c a the ciia chiing. Sa di nhir vay la vi ngoai viec kien tao, cung cap nang lirong cho qua trinh song, vi khuAn con can thirc an cho qua trinh sinh san, bai chiing sinh san rat nhanh, cir 20 - 30 phut vi khuan lai sinh san mot lAn va theo cap so nhAn. Nhu cAu ve thirc an ciia vi khuan co the chia lam 3 loai: - Thirc an nang lirong: Sau khi hap thu se cung cap nang lirong cho hoat d(>ng song ciia vi khuan. Protit, gluxit, lipit la nhfrng thirc an nang lirgng thirang gap. - Thirc an kien tao: Cac thirc an tham gia xAy dimg cau true te bao. - Yeu to sinh tnrang (thirc An dac hieu): La nhimg chat can thiet doi voi hoat dong song ciia vi khuan ma mot loai vi khuan nao do khong the’ tir tcing hgp dirge. Vi du axit amin khong thay the hoac vitamin,... 14 1.4.2.2. Cac loai dinh dirang a) D inh clii'd’n g cacbon T hanh phan c a ban can tao len te bao vi sinh vat bao g6m chu yeu la cac nguyen to C, H, O, N, vi the cac chat dinh dirang ma vi khuan can phai co day du cac nguyen to tren. Trong 4 nguyen to tren thi nuac va khong khi da cung cap day du O r va H cho vi khiuin. Rieng C va N co sSn trong moi truang, mot so lay tir dat, nuac va khong khi. Can c u vao yeu cau dinh duong C va N ciia vi sinh vat ma co the co cac loai dinh duong sau: -f Vi sinh vat tu dirong cacbon: La cac vi sinh vat co the trirc tiep sir dung ngu6n cacbon vo co' nhir C 0 2 va muoi cacbonat. Vi sinh vat muon hap thu C 0 2 hoac C trong muoi cacbonat de’ t6ng hgp nen cac chat huu ca ciia te bao. qua trinh nay can phai co nang lugng tu ben ngoai cung cap. Co 2 nguon cung cap nang lugng: Nang lugng tu anh sang mat trai goi la quang nang. Nang lugng tir cac phan irng oxy hoa goi la hoa nang. Dua vao nguon cung cap nang lugng cho qua trinh dinh duang, kieu tu duang cacbon lai chia lam: Dinh duong quang nang: Mot so vi khuan co chua sdc to quang hop (Bacterio clorophil) nen co kha nang quang hop dugc, tire la co kha nang chuyen hoa trirc tiep nang lugng cua anh sang mat tioi thanh nang lugng hoa hoc tich luy lai trong ATP va sir dung nang lugng nay de chuyen cacbon vo co' thanh cacbon huu ca can thiet e ho ca the. \ 7 du: qua trinh quang hop cua vi khuan luu huynh man luc (Green sunfua bacteria): CO: + 2 U :S Anh Mng mat nq> 1 (Q ,H i:O f,) + H 20 + 2S Luc to \'i khuan 6 Tirang tir cay xanh: CO. + FLO ------------------- > - ( Q H p O j + O, 6 Nhir vay ca hai phan ting d6u sir dung quang nang de tao thanh cac hop chat cacbon huu c a tir C 0 2 va mot chat khac. Dieu khac nhau c a ban a day la: Vi khuan liru huynh thu II tir ITS, giai phong S. Cav xanh thu H tir H:0 giai phong 0 : . Do do cong thuc tdng quat ciia qua trinh quang hop la: CO, + 21 LA — “ Trong do A la — -1g— » - (CriH P0 6) + FLO + 2A Sac to quang hop 6 mot chat vo ca. 15 * Dinh dirang hoa nang: Nhung vi sinh vat sir dung nang lirong cua cac phan irng oxy hoa de chuyen nguon C vo ca thanh chat hfru co' can thiet cho c a the goi la vi sinh vat co dinh duang hoa nang. \ 7 du: Vi khuan Nitrocomonas sir dung nang lirong cua phan irng oxy hoa NIL. s 2 N I I , + 3CO, --------> 2 H N O .+ 7° : 2 H ,0 + 158 calo S i 4H4 47” CXX + 4H +--------- > - ( Q H p 0 fi) + H20 6 Vi khuan liru huynh (Green sunfua bacteria) cung co kieu hoa nang: y* 02 H,S + 0 , --------- > 2 1 1 ,0 + S + 126 calo S i 4Hf Tu do vi khuan k h ir C 0 2 trong khong khi: 126 calo 1 CO, + 4H ------------ > - (CftI 1p O fi) + H-.0 ^ T¥ ^ 6 T Cr cac phan irng tren co the rut ra cong thirc tong quat dang dinh dirang hoa nang nhir sau: Chat vo ca: H2M + 0 2-------- > Chat oxy hoa + Q (nang lirong) CO, + 411+----- > - ( Q , I I p O fi) + H-.0 6 + Vi sinh vat di dirong cacbon: Nhfrng vi sinh vat chi co the phan giai cac hgp chat hfru ca siin co trong moi trirang lam nguon dinh dirdng va cung cap nang lirgng cho hoat dong song ma khong cd kha nang tdng hop dirge cac chat hfru ca can thiet tir nguon cacbon vd ca diroc goi la cac vi sinh vat di dirdng cacbon. Dira vao nguon cung cap cac hgp chat hfru ca, vi sinh vat di dirong cacbon lai chia lam 2 loai: * Vi sinh vat ky sinh: I ii loai vi sinh vat sir dung nguon cacbon tir cac hop chat hfru cO cd san tren ca the vat chu. dd la trirdng hop ciia da so cac vi sinh vat gay benh. * Vi sinh vat hoai sinh: La cac vi sinh vat chi co kha nang sir dung nguon cacbon tir nhimg hop chat hfru ca co a cac xac chet dong, thirc vat, loai vi sinh vat nay cd the thay a moi noi trong thien nhien, chung cd vai trd quan trong lam phi nhieu dat va trong chu trinh chuyen hoa vat chat tir nhien. b) D i dudng N it o' Trong thien nhien, nita ton tai 6 3 dang: nita phan tir, n ita vd ca va nita him ca. 16 + Nito' phan tir chiem mot lirgng nhieu nhat va chmh la dam ciia khi quyen. Trong khong khi, dam chiem 75,5% v6 khoi lirgng, 78,1% v6 the tich. Tinh ra trong khi cjiiyen hanh tinh chung ta co toi 4 trieu ty tan dam (4.10" tan). + Nito' him c a co chii yeu trong sinh vat va cac san pham khong hoan toan cua chimg. Lirong dam nay co khoang 10 - 25 ty tan. + Nito' vo co': I o n tai dirai dang muoi amon, nitrat... so lirgng bang 1% lirgng dam him co'. Vi sinh vai co the sir dung nguon nita a ca 3 dang trong thien nhien. - Dinh dirang nita ciia vi sinh vat rat phire tap va cung chia lam 2 loai: + Vi sinh vat tir dirang amin: La loai vi sinh vat co kha nang sir dung nguon nito' vo c a co sin trong moi trirong nhir NIL, muoi nitrat,... tham chf ca nito' o' dang phan tir va cung co the! sir dung cac hop chat hiai ca dan gian nhir ure, axit amin, protein de tao len cac axit amin va thanh phan chira nito' trong te bao. Cac vi sinh vat tir dirang axit amin co vai tro rat quan trong trong chu trinh chuyen hoa dam trong tir nhien. Nha co vi sinh vat, lirgng dam trong tir nhien luon dirge chuyen hoa iir dang nay sang dang khac de sinh vat co the hap thu, duy tri sir song. Ta co chu trinh dam trong tir nhien: Hinh 1.10. Chu trinh dam trong tir nhien + Vi sinh vat di dirdng axit amin: Gom nhung vi sinh vat co kha nang tong hgp nhieu loai axit amin tir cac hgp chat nito' vo ca va him ca dan gian hay phire tap, song khong co kha nang t6ng hop len mot so axit amin nhat dinh ma doi hoi moi tnrang phai cung cap day dii. Cac axit amin nay phai dirge vi sinh vat sir dung mot cach nguyen veil de tong hgp len protit ciia vi sinh vat chir khong qua qua trinh phan giai thanh NI L nhir cac vi sinh vat tir dirdng. Co the thay sir khac nhau giira vi sinh vat tir dirdng va di dirdng axit amin qua so* do sau: /sv DAI HOC QUOC GIA HA NoT TRUNG TAiVI THONG TIN THU VIEN 0/f030 0 0 2 0 1 1 HNO, ino axit axit J ^ V t M u a n g Protit ____►P e p tit____h Am Amino ^ NH^ V N, Protein vi sinh vat r J D///// ditdng khoang Nhu cau ve chat khoang doi voi vi sinh vat chi can mot krgng nho nhirng co tam quan trong rat lan trong qua trinh sinh trirang va phat trien cua vi sinh vat. Nhirng nguyen to khoang ma vi sinh vat doi hoi phai cung cap vai so lirgng lan diroc goi la nguyen to dai lirgng (macro element): P, K. Na, Cl, Ca,... Nhfrng nguyen to khoang ma vi sinh vat chi doi hoi vai mol so lirgng nho goi la cac nguyen to vi lirgng (micro element). Tuy can thiet nhimg sir ton tai mot cach dir thira cac nguyen to khoang la khong can thiet va co anh hirong xau den qua trinh trao doi chat cua vi sinh vat. 1.4.2.3. Ca che cua sir dinh dirang - De duy tri sir song te bao vi khuan phai thirong xuyen trao dcSi vai chat va nang lirgng vai moi trirang ben ngoai. - Vi khuan khong co co* quan tieu hoa va bai tiet, vi vay toan bo qua trinh trao doi vat chat dirge thirc hien nha mang nguyen sinh chat ciia te bao. Cac chat dinh dirang tir dan gian den phire tap dtki qua mang nguyen sinh chat de vao ca the, nhfrng san pham can ba d6u qua mang ra ngoai. - Vi khuain hap thu thirc an mot cach chon loc va chi hap thu dirge cac chat co cau true phan tir don gian, de hoa tan. Cac chat cao phan tir nhir protit, gluxit, lipit co cau true phire tap khong the thAm thau qua mang te bao vi khuan diroc. Ngirai ta thay icing: protit co phan tir lirgng cao khong lot qua dirge mang te bao. Chi co cac phan tir protit ma cau true khong qua 5 axit amin mai qua dirge mang (day la ch6 khac nhau gifra vi khuan va protozoa, nhfmg loai nay co the an dirge thfrc an ran). Vi vay, de hap thu dirge cac chat dinh dirang, vi khuain phai nha cac ngoai enzym tiet ra moi tnrang phan huy cac hgp chat cao phan tir tao ra cac chat dan gian, d i hoa tan roi mai hap thu qua mang nguyen sinh chat. Proteaza Peptitaza P rotit---------------- ► Polvpeptit—— ---------- ► Monopeptit -> axit amin vi sinh vat vi sinh vat Lipaza L ip it-------------- ► glyxerin + axit beo vi sinh . Amilaza G lu xit--------------- ► D extran---------- ► Glucoza Xellulaza 18