I'ep chi Cimg nghe Sinh hoc 1(1(2)

I'ep chi Cimg nghe Sinh hoc 1(1(2): .187-192. 2012

PHAN L A P \ I K H U A N O X \ H O A S U L E I D E I R O N ( ; |>|l |l K I E N lUlV KHJ \ A K> KII Ngiiun Minh (;i:nig, Ngnyeii Ihj ilant;, Phan Ihi iMiiion(> lion. Dinh Ihtiy Hilng

Vien Visiiih vgl vd Cdng nghe smh hoc. Dgi tigc (Jiioc (,ni ltd .\,ii

\(m '1A1

\'i kliii.ino\j lioasullidcliicuklii \;i quang hop k> khi diroc lam giau tinniiu iiuia :.:icii!j kiu>aii nliiem sfii va mSu biiiidaylut Ha Mini Uong moi Huong klioang dKli llie cluni ihiosulf.itc va suilidc luong img kiclial cho dien luduy nhat, ll.ii cluing vi khuan i i {iiiOii khi) \a 1*7 (quang imp l,y Mii) duoc pii.in i,;\p v.i iinli sacii Urong ung lif cac mini lam iiiaii iidi lien the hien kha ii.'iiii; o\v hoa >.,io il<ii v6i sullide Uong dieu kien hien klii va ky khi. (1iiiii;j I ! oNv hda Millidcliiaiihsuliale lich ICiyiiiHig dich uiii.i va i,im !;i.im pll cua moi linang, lumg kin Jo cluing I'" Jinvui ho.iNullide ih.inh sulfui lifr od,,iii!; hat Uong lc hao v.i m llie quan s.U duoc dudi kinh iiicii VI Cahai chungdcu CO kha ming sinh Huong o miii linongciniiingdo suilidc tao(o min. iic ciic doi vdi iihiai loai siiil) v.~iU D:IC biel eluing P7 co kha nSng siiili iiuoiig loi uoiig moi liiidny co iiiiiigdo suilldc 9 mM v.i du bl ire clic o ndng d(i 15 mM So s.inh liinh lir g.in du cua ioS iDN \ tu hai chung n.iy cho phep dnih danh tuong img lii Thiohacillus sp I < va lllo, liromaliinn sp P7 Kel qua nghien ciru bicdc diiu g^ii mo kha nang img dung cua c.ic ehung vi kluiiin nay Uong vice \ u l y ci'ic ngnon thai co ham imnig suKiile can

Tirkluia: •Mloihrnmoliuni. hiiu kill, oxy hoa \i,Hi,l,- i/iuiiin hop ky klii, Thioluii illiis

MODAU

Suilldc la hop chal luu hujnh co muc o \ \ hda thap nhat { 2). cd the bi oxy hda bang o\> Ining khdng khi ha\ bang mot sd loiii v i sinh vat (Hursc el III, 2008) Sullide duoc tiio ra tir qua trinh phan giai cac hgp chat sulfur hfm ca va lir qua trinh khu sulfate do \i khudn khu sulfate thuc hien (Widdel, Back, 2000). Sir cd mat cua sullide trong chat thai gay miii khd chiu ddi vdi mdi trudng xung quanh (Billon, 1999), Ben canh dd, suilldc cdn cd anh hudng ddc hai tdi cac co the sdng. bao gdm ca ciic sinh vat bac cao va vi sinh vai. 0 ndng dp 200 ppm sullide uc ch4 sinh trudng cua nhieu loai vi khuan (Billon, 1999), Ddi vdi cay trdng, sulfide gay ihdi re.

lam giam kha nang hdp thu chat dinh duong ciia cay (Dobermann, Fairhurst. 2000). Con ngudi li^p can vdi sulfide d ndng dd thip (150 ppm) cd the bi dau dau, chdng mat, d ndng do cao (700 - 800 ppm) cd thi bit tinh hay rdi loan tim mach (Mandavia. 2011).

Trong tu nhien sulfide cdn la chit gay an indn kim loai manh, dac biet trong mdi trucmg bien do ndng dp sulfate cao trong nude bien tao dieu kien vi khuan khir sulfate phat triin smh sulfide (Widdel. Back.

2000),

Do cd mirc oxy hda thkp, sulfide co the trd thanh ngudn dien tir cho qua trinh di hda va bj oxy hda thanh sulfur d cac muc oxy hda cao han_ nhu S (nguyen td sulfur) hay S'^ (sulfate). Mpt sd loai vi smh vat cd kha nang tan dung nguon nang luong

nay. cluivcn hda ihanh ATP de sinh Iruong. liong dieu kien hieu khi, cac loi'ii Thiobaiilliis la diii dien quan Irpng nhat su dung oxy de oxy hda c<ic hop chat .sulfur tr mirc oxy hda thiip (tiong dd co sullide) thanh sullale (Kobertson. Kuenen, 2000; Sorokin et al, 2000). Trong dieu kien ky khi, vi khuan quang hpp khdng smh oxy (anoxygenic photoliophs) la nhCfiig dai dicn sir dung sullide lam nguon dicn tir trong pha tdi, sulfur Iao ra duac tich ICiy ben trong te bao (nhu a Chromalinin) hay ben ngoai te b;io (nhu d Chtorolmim) (ImholT. 2000, Overman, (iaicia- Pichel, 2000),

Trim the gidi, viec su dung cac loai Tliiobai itlns hay Chroinatiuin va Chlorobium de loai bd sullide trong nude va khdng khi da dirpc biel den qua nhieu nghien cim (Khanna el al, 1996, Takashima el ai.

2000; Wang d al, 2005) cung nhu img dung ihirc t^

(Chen d al, 2008; Hurse d al 2008). Tuy vay. d Viet Nam ITnh virc nay cdn it dupe de cap, Trudc tinh hinh d nhiem mdi trudng d mirc bao ddng nhu hien nay thi vice nghien ciru cac nhdm vi sinh vat nay de dua vao img dung la can thii-t,

VAT I lEU VA PHU'ONG PHAP NGHIEN CUl) Lam giau va phan lap vi khuan oxy hda suinde Mau biin ky khi day hd Ba Mlu (Ha Ndi) va mlu nude giing khoan nhiem sat dupe sir dung tuong img lam ngudn vi smh vat ban dau de lam giau 387

Nguyen Minh Giang el ai va phan l^p vi kluiiin quang hpp ky khi luu huynh vii

vi khuan hieu khi lliii(ic chi Thiobaeilltis.

Doi \di \ i khuan quang Inrp ky khi luu huynh, vK'c \km %\kn dupe lien hiinh Irong binh serum 100 ml (Hinh IA) chira tndi trirdng khoang djch tli^

(NaCl I g. MgCh.fill-O 0.4 g. CaCL 2H.() 0.13 g, Ki ! 0.5 g. N H / 1 0.25 g. K l L I ' d , 0,2 g.

MgSt), 7H;(> 0.25 g. nirdc cat 1000 ml). I ml moi I091 dung dich viiainm va vi lir(,Tng (Widdel. Back, 2000), dupe I091 bo o\v b3ng siic khi nito v^ bii sung Na-S (ban dau la 2 111M \;i liOp Uic bo sung tr nong dp nay sau min 2 iiga> nudi cii)) lam chat cho dii'n tu. Binh nudi dupe djt n nhivl dp 30''C. lii-p .xiic hen tgc vni kn\\ sang trAng. Phan l^p chiing thuiln khidt dupe lien hinh qua dil\ pha Inilng liong mdi trirdng tuong tp cd hd sung thgch a ndng dp 1"» ( at khuin I9C don ( d c a c ong pha loSng 10 . 10 ^) (I linh IB) dupe tach neng bang pipel Pasteur va chiivcn sang mdi trudng dich the ky khi

Ddi vdi VI khuan hieu klii thupc chi Tluobacillus.

V li'c lam giau dupe tien hanh trong biorcactor (Hinh 2) dung tich 1 lit chira 300 ml mdi trudng khoang djch thi (NHjCI I g, MgCU.dHjO 0,5 g, MgS04,7H20 0,3 g, KH.PO., 0,4 g, K^HPOj 0,6 g, CaCl:.2H:0 0.2 g. FeCl3.6H:0 0,02 g. nude cit 1000 ml) chira Na;S;0) (1%) lam chat cho di?n tu (Robertson. Kuenen, 2(K)0). Vi khuin trong bioreactor dupe cung cap oxy lien tyc nhd thiet

bi sue khi va khuay tir (Hinh 2), Phan Igp chiing thuan khiet dupe tien hanh tren mdi trudng cd thanh phan nhu trong budc lam giau dupe bd sung thach (1,5%).

X^c djnh boat tinh oxy h6a sulfide cua cdc chiing thuan khiet

Ddi vdi vi khuan quang hpp ky khi, hogt tinh oxy hda sulfide dupe xac djnh thdng qua djnh lirpng ndng dp S " trong mdi trudng bSng dung dich ddng sulfate (Zengier, 1999), Mpt each tdm tit. liy 0,1 ml m l u vdi 2 ml dung dich ddng sulfate ( C u S C 50 mM, HCI 1 mM) vao dng nghi?m, trpn deu bing vortex trong 10 giay va IJip lire do m^lt dp quang hpc d budc sdng 480 nm.

Ddi vdi vi khuin hiiu khi, hoat tinh oxy hda sulfide duoc xac djnh thdng qua dinh lugmg S O / "

tao ra trong mdi trudng (Massuomi, Cornfield, 1963) Trong phuong phap nay, lupng _S04"' cin xdc djnh ket hpp vdi ion Ba * tao thanh kit tua BaSOa sau dd dupe xac dinh thdng qua mat dp quang hpc is budc sdng 420 nm.

NKhiCn cuu hinh th^i

I linh th^i ciia ckc chimg vi khuan dupe xdc dinh ddi \in lc biu> d pha sinh trudng luy tien. Djch te bao dirpc ly t^m 10,000 vdng/phiit trong 5 phiil, sau do sinh khdi dupe hda trong 200 ^1 nude muoi 0,9% va diing liim li6u b^n tr£n phien kinh phii agar, Anh t i bao dupe chyp dinii kinh hien vi phan pha, dp phdng dgi 1000 Ian.

Tdch DNA tiing so, khuech dai \k g\k\ (rlnh ti^

IftSrDNA

DNA long sd lir ckc chimg vi khuan dupe tach chii'l iheo phuong phap ciia Marmur (1961) vdi mpt so Ihay doi de loi uu hda. Gen ma hda cho 168 rRNA (1500 bp) dupe khuech dgi trong phan ling PCR su dyng c5p moi 27F (AGA GTT TGA TCC TGG CTC AG) v i 1492R ( G G f TAC CTT GTT ACCi ACT T). San pham PCR dupe tinh s^ch va giai trinh tp vdi ABI Prism BigDye TerminatCH" cycle sequencing kit va dpc trinL tp tren may ty dpng 3110 Avant Appied Biosysten s. Trinh ty gen sau dd duac phan tich so sdnh vdi trinh ty 16S rDNA cita cac loai cd lien quan hi^n Ak cong bo tren Database DDBJ/EMBL/GenBank su dyng cdng cy BLAST Search. Cay phan logi dupe dyng theo phuong phap neighbour-joining (Saitou, Nei, 1987), trong do djnh dgng cay dupe tien hanh dya tren 1000 phep so sanh da chieu (Felsenslein, 1985),

KET QUA VA THAO LUAN

Lfim gifiu \ii p h a n lap vi khuan o\y hda sulfide trong di^u kifn ky khi \k hieu khi

Tir mlu bun day hd Ba Mau. M khuan quang hpp ky khi Ak dupe lam giau trong binh serum the tich 100 ml chira 50 ml mdi trucmg khoang djch the dupe logi oxy hoan toan va Na2S lam nguon di?n tir duy nhat. Binh nudi dupe chieu sang lien tyc bing anh sang tring (budc sdng 400 - 700 nm), tai nhiet dp 28 - 30''C. Sy cd mgt cua vi khuan da luu huynh de dang dupe nhgn biet thdng qua sic td do (do thinh phan carotenoid trong te bao vi khuan) xuat hi^n Irong mdi trudng nudi ciy theo thdi gian (Hinh 1 A). Tir quan the vi sinh vgt da lam giau nay, chiing vi khuan quang hpp tia luu huynh P7 dupe phan I|p qua day ong thgch ban Idng (Hinh IB) va ehuyen sang mdi trudng djch t h i . Dudi kInh hifin vi quang hpc cd the quan sdt thiy chimg P7 cd t i bao hinh oval, kich thudc 3-4 x 6-8 (im, ben trong cd nhiiu hat tich tr& luu huynh (S") (Hinh IC), la san

Tgp chi Cong nghe Sinh hoc 10(2): 387-392, 2012

pham ciia qua trinh oxy hda sulfide. So sanh trinh tu la Athctiromalium vmostim vdi 97% dp tuang ddng gan du cua 16S rDNA cua chiing P7 cho phep \tp (Hinh ID) Chiing P7 do vay dupe dinh danh la chiing nay vao chi Allochromalium, \ok\ gan gui nhat Alhctv-omalium sp P7.

(

⁷³

1000 -P7

7I9|

Thiocapsa mihoffii (Dy49SX28)

®

m^

-Altoehromalnim i-z/wv/w; (PM 17S2(iS) Athii hi onialium rennkae (AM399029) -Allocluoinaiiiim Iriipen (AM902495) nocvstis r;,i/,;,,-,v(FN293059)

Hinh 1 , Nu6itich luy va phSn lap vi k h u i n quang ho'p lia luu huynh chiing P7 1 A - d | c h nuoi tich luy t u m l u biin day ho Ba m l u I B - khuan lac (Jan cua vi khuan quang hgip ky khi luu huynh phat tn^n trong ong thach ban long, I C - hinh thai te bao cua Chung P7 viiri cdc hat luu huynh ben trong le bao b a r = 10 fim, I D - c S y phan loai neibourgh joining dua tr§n tnnh tir 16S rDNA g i n du cOa chiing P7 so sanh voi cac loai vi khuan luu huynh trong ho Chromatiaceae Tliiocapsa imhoffii dupe chon lam outgroup

©

3 e.

2 d

Hinh 2. Lam giau vi khuan Thiobacillus A - bioreactor \&m giau vi k h u i n Thiobacillus, B - Oxy h6a S i O s " trong bioreactor lam giau vi khuan Thiobacillus dan den Ihay d6i pH va lich lOy S O / " trong moi tru'6'ng

Vdi mau nude gieng khoan nhiem sat lam ngudn vi sinh vat ban dau, vi khuan hieu khi oxy hda cac hpp chit luu huynh dupe lam giau trong he thdng bioreactor dung tich 1 lit (Hinh 2A) chira 300 ml moi trudng khoang va Na2S203 (10 mM) nhu ngudn dien tit duy nhat.

De dam bao oxy cho qua trinh oxy hda thiosulfate, mdi trudng trong bioreactor duoc sue khi lien tuc va khuiy diu tren may khuay tir. Binh reactor dupe dat tai nhiet dp dn dinh 28 - 30°C, trong dieu kien khdng cd anh sang. Qua trinh oxy hda SiOi lam giam dp pH ciia moi trudng do su hinh thanh H* (theo 389

Nguvi'n Minh Giang e / o / phinrng trinh phan img S-O,'

2SI),- ' 211). S.III 2 iiuin nudi cn\.

irj dudi 4. ddng thdi smi phiim S(), (Hinh 2B). chirng to quii irinli o \ \ dii'ii la lich cpc

Tir quiin tlw vi khii.in bioreactor mo ta c trim, chi

dupe limi iii.ui irong

\iii \\ khuiin 1 3 dirpc

phiin Igp v;i tinh s^ich tren mdi trudng khoang thach CO tiiiinh phim tiumg ty nhu mdi^ truimg lam giau, Cliiing vi kluian ntiy gdm nhO'ng te bao oval, cd kich ihirdc 2 ' 3 |,im (Hinh VA). it ehuyen dpng trong moi iniang dich the. So s.inh irinb ty 16S rDNA cho phep \ep cluing 1 ^ \iio chi Thiobacillus. loai gan giii nhal la T ilno/uiius (tv I? tuong ddng 96%) {Hlnh3B).

„,lh,^ ll„„l.„n,v,]l\l[-!}6'i4i 11,,' ,h„,i,-,l„.fhi.\S2A^i44)

/,h,ml-.,pliih,'l.\!}\66m

ivi:i7.t|

.'i-iHgi98585) Hmh 3. Hinh thdi i4 bdo vd vi tri phdn loai cita chung T3 A - Hinh Ihdi 1^ bdo cua chiing T3 ducri kinh hi^n vi phdn pha. dO phdng dai 1000 >• (bar = 5 nm), B - cdy phdn loa> neibourgh joining du'a tr€n trinh t u 16S rDNA g i n du cua chung T3 so sdnh vPi cdc lodi vi g i n gui Pseudomonas resinovorans d u p e chpn Idm outgroup

®' ®

Hinh 4. Smh trudng k4t hop 6xy hba sulfide ir chung Allocliromatium sp P7 A - mdi d ^ quang hoc cua dich te bdo (n) tang kem theo s u gidm cua n6ng do S'' (•) trong m6i tru&ng nu6i c i y B - m^l dO quang hpc cua dich 16 bdo trong mfli Iruong cd b6 sung S^ d cdc ndng d ^ k h d c nhau

Oxy hda sulfide d c a c chiing P7 \ a T3 Sinh truong cua chung P7 phy thupc rd r?t vao sy cd m^t cua sulfide tronj; mdi trudng nudi cdy, Dd thi tren (Hinh 4A). cho thay dudng cong sinh trirong bieu ihi bang gia tri OD do d budc sdng 600 nm vii dudng cong bieu thi su thay ddi cua nong dp sulfide trong mdi trudng (do bang mM) la hai dudng cong gan nhu ddi ximg nhau. chimg td lupng sulfide trong

mdi truimg nudi ca\ da dupe \ i khuan su dung de tich luy smh khdi D?ic biet. chung P7 the hien kha niing sinh truang ldi uu o ndng dp H:S tren 9 mM (Hinh 4B). la ndng dp ddc hai ddi vdi phan Idn cac loai sinh vat soni; (Bitton. 1999) va chi bj ire che d n d n g d d 15 mM H:S irong mdi trudng.

Khac vdi chung P7. chiing T3 sinh trudng nhd oxy hda sulfide bang oxy phan tu nen cd nhu cau

Tgp chi Cdng nghe Smh hgc 10(2): 387-392, 2012 oxy rat cao, Tdc dp oxy hda cao nhat dien ra d ngay thir 2 va 3 (Hinh 5), sau dd giam ddng k i do pH trong mdi trudng giam (tdi mirc dudi 4 sau 4-5 ngay nudi cay).

Cdc ket qua thu dupe cho thay hai chung Allochromalium sp. P7 Vii Thiobacillus sp, T?> ciing CO kha nang oxy hda S"' nhung su dyng cdc chat nhgn dien tCr kliac nhau la C O . (d chung P7. theo phuang trinh phan img H;S + CO^ - * (CH:0) + 2S) va Ol (d chimg T3. tlieo phuong trinh phdn img H.S + 20n —• HjSOj). Tai cdc Uiuy vyc cd ham lupng sulfide cao, cdc chung \i khuan nay cd the ddng vai trd quan trpng trong \ ice logi bd tlianh phan chat dpc hgi nay trong nude (chimg T3) ha> trong biin day (chiing P7).

Ldi cdni O'n: Nghien ciru nd]' dirge ihtir hi('n nhdsu hd Irg kinh phi lir de Idi cap co so Vi('n Vi sinh vdi vd Cong nghe sinh hoe ndm 2010 do TS Phan Thi Phtrong Hoa chu Iri.

60 90 120 ISO

Hinh 5. C h u y i n hoa S^ ( • ) t h a n h S O 4 ' " ( • ) o chung Thiobacillus sp. T3 trong bioreactor

Vi khudn oxy hda sulfide d dieu kien ky khi (chiing P7) va hieu khi (chiing T3) duac phan Igp tit mdi trudng nude ngpt, tuong img la bim day hd Ba Mau va nude ngSm nhiem s a t Hai chung nay cd kha nang sinh trudng trong moi trudng cd ndng dp sulfide cao (9 mM ddi vdi chiing P7 vd 5 mM ddi vdi chung T3), sit dyng sulfide lam ngudn di?n t u de sinh trudng, chuyin hda ve dang sulfur (chiing P7) hay sulphate (chiing T3) khdng dpc. So sanh trinh ty 16S rDNA cho phep djnh danh hai chimg nay la Allochromalium sp. P7 va Thiobacillus sp. T3, cac loai gan giii tuong ung la Allochromalium vinosum (97% tuong ddng) va T. thioparus (96% tucmg ddng).

Vdi kha nang oxy hda sulfide cao, chimg vi khuan P7 va T3 cd tiim nang ling dyng trong vi^c loai sulfide tii cdc mdi trucmg 6 nhiSm.

vrohiology. John Wiley &

TAI LIFU THAM KHAO Bitton (r (1999) Wasleiia, Sons. New York, USA.

Chen C, Run NQ. Wang AJ, Yu ZG, Lee DJ (2008) .Simultaneous biological removal of sulfur, niirogcn and carbon using EGSB reactor, Appl Microbiol Biotechnol 78.1057-1063

Dobuimann A, Fairhurst T (2000) Rice nun-ient di.soiders and nutnenl management. Handbook series, Oxford Graphie Printers Ltd,

Felsenstein J (1985) Confidence limits on phylogenies. an approach using the bootstrap. Evolution 39' 783-791.

Hurse TJ, Kappler U, Keller J (2008) Using anoxygenic photosynthelic bacteria for the removal of sulfide from wastewater In Hell R, Dahl C, Knaff D, Leustek T (Ed ), Sulfiir Metabolism in Pholotrophic Organisms 1st ed.

The Netherlands Springer 437-460

Imhoff JF (2000) The Chromatiaceae In Dworkin M, Falkow S, Rosenberg E, Schleifer KH, Stackerbrandt E eds The Prokaryotes: an Evolving electronic resource for the microbiological community Springer-Verlag, New York Khanna P, Rajkuma B, Jothikuma N (1996) Microbial recovery of sulfur from thiosulfate-bearing wastewater with phototrophic and sulfur-reducing bacteria Cur Microbiol 32:13-37.

Mandavia S (2011) e-Medicine Toxicity hydrogen sulfide, available at blip //emedicinc niedscape.com/aiticle/

815139-ovcrview, accessed in May, 2011

Marmur J (1961). A procedure for the isolation of deoxyribonucleic acid from micro-organisms, J Mol Biol 3:208-218

Massuomi A, Cornfield AH (1963) A rapid method of determining sulfate in water extracts of soils. Analyst 88.

321-322.

Overmann J, Garcia-Pichel F (2000) The Phototrophic Way of Life. In Dworkin M, Falkow S, Rosenberg E, Schleifer KH, Stackerbrandt E eds. The Prokaryotes. an Evolving electronic resource for the microbiological community. Springer-Verlag, New YorL

Robertson LA, Kuenen JG (2000) The genus Thiobacillus In Balows A, Trueper GH, Dworkin M, Harder W, Schleifer KH eds. The Prokaryotes: an Evolving electronic resource for the microbiolo^cal community. Springer- Verlag, New York

391

Nguyen Minh Giang et ai Saitou N, Nei M (1987) Ihc iieiglihor-ioming meihod ii

new method for rcconsiriiding phyloijcnclic trees, Mni Biol Evol A: AM^-A2f'

Sotokin D^'. Rohcilson 1 A. Kuenen J<. (20III)) Isolation and diariicteiiAiiion of alkaliphiiic. i.hemoliiiio.iuiolro|iliic.

siifur- o\\di/ing hjclcri.i liii-nie van Lecincnhoek 77:

l'^\-2bl

l.ik.ishim.i i, Nishiki 1, Konishi V (2000) Anaerobic oMdaliiHi ol dissolved hydrogen suilldc in continuous culture ol the phuioirophic haclcrium I'rostliecoctitoris ae.siuani Em non Biotcchiml X-) 247-251.

W,ui^ AJ, Du DZ. Ren Ni^, van Giocneslijn JW (2005) An innoviilive process, of simultaneous desulfurizalion and denitrilicalion by Thiobacillus denilrification, J Environ Sci Health A 41): 19.19-1949

Widdel r. K.ik 1 (2000) (;rdm-negalive mesophilic sulfale- rcducing biiLicriii In Balows A. Trueper GH. Dworkin \I.

Harder W. Schleifer KH eds. The Prokaryotes: an I vnlving eteitnnii,' lesoiiire /or the microbiological eomninnily. Spnnyct-Vcri.iy. New York.

/cngler K(I999) PhD Disi (icrinany.

aiion, Universiiv of Bremen.

isol vnoNoi \i Hoim \\\) \\\\ KOHK SI I.IIDKOXIDI/JN*, BACTERIA

N'^inen Minh <.i;iiiu. N;:IIM-II Ihi Hunt:. Than I hi P h u o n s Una. Dinh Thu> H a n g ' Institute ot Microbudogy and Hmtc, liinil,>g\ I idiiain Salnnial Universily of Hanoi

SLMMARY

Aerobic sultur-o\idi/-ing and anaerobic phototrophic Miifide-oxidi/ing bacicna were enriched from ferTou!.-coniaining groundwater and anoxic sediment from H.i MJu lake, using mineral media with ihtosulfate and sulfide as elcciron donors. Two strains T3 (.icntbic) and P7 (anaerobic, photouoph) were isolated and punfied from llicse cnrKiiineni cultures under OMC and ano.xic conditions. respeai\ely. Strain T3 o.Mdized sulfide to sulfate that jccumulaied in the culture medium and lowered its pH. whereas slrain P7 con\erted sulfide to sulfur deposited in the form of granules inside the cells and could be Msible under microscopy. Both strains showed high aclivity in ihe oxidation of sullide (at the inhibitory concentrations to man\ other sptxies) under aerobic and anaerobic conditions, respectively In particular, strain P"" was able lo grow in the medium supplemented with sulfide dl i\ie concentration as high ,is 9 niM and was inhibited only at ihe concentration of IS m \ | Based on the 16S r l ) \ \ sequence data, strains 13 and P7 wen- JCLordingh designated as Tluobacillus sp T3 ^nd Allochromalium sp P7. The obtained results indicated die application potenlial of the strains T3 and V for the irealmeni of sulfide in contaminated sources

'irds. Aerobic, anoxygenicphoioiroph. sulfide oxidation. Chr Thiobacillus

Author for corresponder.

392

.• E-mail; hansdinh cblmjci'yahoo com