HOI NGHj KHOA HOC C O N G NGHE SINH HOC T O A N Q U 6 C 2013
NGHieN CLfU CAItHlEN CHAT LLTONG N U S C TFIAI CHE B I I N TINH BQT SAN B A N G CHE PHAM VI SINH VAT
VQThuyNga'.LiKmgHChiThanh', Pham van.Toan\ . . . - . . - - Wl4n Mbi trubng Ndng nghi$p, Vi$n Khoa hgc Ndng nghiep Vi^t Nam
'V^n Khoa hgc Nbng nghifp Vift Nam
T6M TAT
Nu6c thii nhi may ch^ bien s ^ xuit tinh b$t sin da va dang la n g u ^ gSy 6 nhilm mOi tmong. M&c di^ d3 co h; th^ng xi ly nuoc M i , song do nhieu nguyfn tih3n kbic nhau, hifu qu& xii 1^ cia nhiea nhi asky chua dat ygu cau. Nb9ni IdiSc ph\ic tinh t^mg o nhilm do nubc thii chi biSa tinh I)$t s ^ , cdng trinh nghjfo cftu tip trung tuyin chgn b^ giSng vi sinh v$t c6 hoat thih sinh h^c cao, sin xuil vi Ihig dyng tbi phim vi sinh v ^ Sk ning cao tiifu qua xii ly nuoc thii sau biogas cua nhi may ch^ biSn tinh b^t sin. Kit qui nghiSn ciiu d i tuy&i chgn 3 ch^g vi sinh v|it gom Bacillus velezensis, Streptorrryces fradiae vi Nilromonas. sp c6 khi nang chuyin b6a tot hpp chit hihi 00 trong nu^c thii ch^ bien tinh bgt sin. Ch^ phim sinh hpc.MIC-CAS t?o ra tCr tS h(»p 3 chiing vi sinh v%t tuyin chgn c6 tic dvmg giim 76,2% COD vi 89,7% BOPj sau 3 ngiy x i 1^. tJTng dyng chl phim trong xii Ij' nuoc thii tfi nhi miy chl biln tinh bgt sin ELMACO Ninh Binh cho thiy nu6c &ii sau xii 1^ dit dip iing yfiu ciu thw QCVN 40-2011/BTOMT (cOt A) vi dii dilu kifn thii la h$ th6ng nu6c thii cong c^ng.
Jiir hiida: Chl biln tinh b$t san, che phim vi sinb v$t, chuyen h6a hpp chit hiiu co, nude thii, xCr Ij' MdDAU
Theo &6 li§u ^ n g Vii. ViSt Nam c6 khoSng 100 nhd m^y chS biSn dn xuit tinh bQt san cb quy mb vira vk ibn vdi tSng cflng ]suit l<hoSng 3,8 tri$u tiin cii tuoiln&m vi nhilu ccr sb ch4 biln quy mS nh6 phSn b6 hSu hSt b dc tlnh/ttiSnh tnang d nube (Trung tim sin xuit s^ch Vi$t Nam 2009). Cic thanh ph^n h&u ca nhu- tlnh b^t, protein, xenluloza, du*ng co trong nguydn li$u eii s^n lircri ik nguySn nhdn gdy 6 nhiSm cao cho dc ddng nude 9\ki cOa nhk mky skn xuSt dnh bgt sin.
Ngodi chit thdi ran, cdc nhd mdy ch6 bi^n tinh b$t sin dlu thdi ra mdi Im^ng mflt lu'gng nu'^c thdi khSng |6, Irung blnh khodng 8-12 m^ niffrc thdi/1 tin tinh b^l. Nubc thdi sau qud trinh chi biin flnh b$t sin d dc thOng s6 d$c tnrng: pl^, thip, hdm iif<7ng chAt hiiu ca cao, thi hi#n qua ham lu^ng chit ran lo lOng (SS), T5S rit cao, cdc chit dinh dirong cliCpa N, P, cdc cht s6 v l nhu clu oxy sinh hgc (BOD5), nhu ciu oxy hod hpc (COD), ...vugt nhilu'lln so v6i tidu chuin, qui chuin ky thuat mdi truing vd Id nguyen'nhdngdy 6nhi€m mfii tru&ng smh thdi Cining tim sin xuit s^ch ViftNam 2009).
ok xi> 1$ nguin nu-dc thdi phdt sinh trong qud trinh sdn xull, cdc nhd mdy chi biin tinh bflt san diu xdy di/ng h$ thing xi> 1;^ nu'dc thdi. Tuy nhidn tikn tivj/e t l phan I6n cdc h$ th6ng x^ 1;^ nirdc Ihdi ho^t dgng chu^ hi$u qua n6n chat lirpng nude thdi sau xCr 1;^ khfing ddm bdo tifiu chulin xd thdi theo qui djnh, Irong dfi cfing ly trdch nhi$m hCru h^n rn^l thdnh vifin (TNHH MTV) Tlnh bgt sin ELMACO-Ninh Binh Id mftt vidy. Bao cko quan trie cua Nhd mdy (nam 2009 vd 2010) vd kit'qud khdp sdt cua Tdng cgc Mfii tnrdng (nam 2009) xdc £^nh nu^c thai sau xir ly cua h$ th6ng chua d^t Quy . chuin 1^ thu$l quoc gia QCVN 24:2009/BTNMT. Nham hb trg doanh nghiep khJc phgc tinh tr^ng fi nhiSm nu'dc thdi bong chi biin tlnh b^l san, nhfim nghiSn ci>u cua Vi$n MSi tnidng Nfing nghifp da triin khai nghifin ci>u cdt thifin chit lup'ng nude thdi ch^ biln tinh bOt san bang chi pham vi sinh v|t thuflc n^l dung d i tdi "NghiSn ci>u sdn xuit chi phim vi sinh v$t xi> 1;^ nude thai nhd mdy chl bien tinh bfltsln"doyjfin_Moi tn/dpg Nfing nghifp chiilrl, . ^ - .•-- -- NGUYgN Lieu VA PHU-aNG PHAP
Nguyin ll^u
Nude thdi Cfing ly TNHH MTV Tlnh bflt sAn ELMACO - Ninh Blnh.
Bfl giing vl slnh vdt phdn Igp Kr nu*c Ihdi nhd mdy.
Phuo'ng phdp
Phucng phdp liy mSy, v^n chuyen mlu vd'bao qudn miu Hieo TCVN 4556 - 83. ' * Phucrng phdp vi sinh v$t; phftn l$p, xdc ajnh m^t dg, hogt tinh sinh hgc theo Egonsv (1976).
Phuong phdp xdc i^nh cdc chi tieu trong nude: Xdc djnh BODs flieo TCVN 6001:1995, xdc djnh COD theo TCVN 6491:1999 (ISO 6060:1989). phdn tich phospho t&ig.si theo TCVN 6202:2008 (ISO 6878:2004), xdc djnh nita ting so theo TCVN 5987:1995, xde djnh hdm lug-ng ting chdt rin Icr ICpng TSS flieo TCVN 6625:2000 (ISO 11923:1997).
Djnh tfin vi sinh v|t Iheo phuang phdp phdn tieh gen 16S rDNA.
Phuangphdp xit ly nude Ihdi:
Xi> If' giin dogn: cho lu^ng nude thdi nhit djnh vdo b l chira, cip khf euung bi>c, bo sung chi phim vi slnh vkl Xdc d\nh hdm luang BODj, COD ban dlu vd nhiJng ngdy tiip ttieo (cdc b i chi>a co dung tich 60 - 80 lit)
Xlf 19 liin tgc qd mb nhd' Hfi thing gim 3 bi: b i chua nu6c thdi, be xO 1^ vd b i ling. Cdc b i dugc noi vdi nhau bSng
ing diri, cd van dilu ehlnh iuu lugng nude chdy. Dua nufi'c thdi cin xi> IJ vdo b l . Dieu chfnh van cip nude tir b i ehi>a
dl vdo b i xi> ly. Bfl sung 5 g chi phlm/m nufirc fliai luang ducmg m|it flfl 5 x 10^ CFU/ml vd cip khi cudng bue co
khuiy trong thdi gian 8 gid trufire khi din vdo b l i i i g . Luvng khi cip luang duang 6 mg/Ilt nude thdi. Phdn lich chit
lug-ng nude thdi tnjfi'e vd sau xi> 1;^ bing cdc phuong phdp b trin
HOl NGHj KHOA HQC C O N G N G H ^ SINH H p C T O A N Q U 6 C 2013
Thl nghi$m d i i chung thgc hien tren h? ttiing xO' ly gidn dogn, x u ly Iidn tgc t u o n g t u nhung khfing b i sung Xi> 1^ liin [yc tai hifn trubng nhi miy che din tinh bbt sin: ^ . hAynqdy THI nghi$m d u o c thi/c hign tgi cfing ty TNHH MTV Tinh bflt s i n ELMACO • Ninh Binh d c 6 " 9 ^ " f l ^^'U^aasvk bk lang v d i krgng nufic thai trung binh Id 1400 - 1500 m^/ngdy. N u d e flidl d u a c xir ty thflng qua he ' " ^ P R ° ~ f . ^ ^ ^^ t h i n g dgng. Thl nghi$m si> dgng 5 g c h i p h i m cho 1 m^ nude fl\ai b efing do?n x u ly frfin ttilfit bi syc • < " ' « " 9 , ^ ^ ^ chi sgc khi sau btogas. C h i t l u g n g n u d e Uiai sau biogas vd sau x u IJ b i n g c h i p h i m VSV d i r v e phdn tich, aann g tifiu sinh, hoa hgc Iheo phuang phdp d trfin.
KtT QUA v A T N A O LUAN
Xic dinh bb chOng vi dnh vft vi sin xuit ch4 phim x u /j? nuiSrc thii sau chi blin tinh bbt sin
Trfin CO s d ddnh gid hogt Unh sinh hgc, nhom nghifin edu dd xdc dinh d u o c bfl chung vi sinh v | t (VSV) co k n 9 c h u y i n hfia c h i l hiru c o s o dgng trong xCr ly n u d e flidi nhd mdy c h i b i i n tinh bflt s i n vd t i n g hpp ' ^ " 9 ^ f | J ; « ° ^ ChOng S H X 1 2 c h u y i n hfia ceHutose. tinh b^l, chOng SHV.22 c h u y i n hda h o p c h l l photphat khfl tan vd e t " " ^ ^ chon c h u y i n hda hop c h i t chOa nito. K i t qud ddnh gid khd ndng logi bfl hop c h i t cacbon. N v d P eua cdo VSV ^ y e n crign duoe A l l hifin trong Bdng 2 cho t h i y cde VSV l u y i n chpn efl khd ndng logi bd 7 0 % h o p c h l l cacbon. 9 2 % hg-p cnat N vd 86% hgp c h i l P.
, B i n g 1.Ho;l Unh stnh h9c cua c i c chUngvl slnh v^t
Khd nang phfln glii hop c h l l hChj co cila vi sinh v j t KlhljuctiiJng Phfln g l i i Pbdn giii tinh Phfln gidi hoP PhSn giai
CMC bfit chit chlia N photphat kha tan (tM=mni) (CW=mm) "fin k i t (mgfl) (D-d=mm) SHX12
SHV.22 SHV. 0 A 7
B i n g 2. K h i ndng lo^l bd hgp c h i t hOu c o v^ khoang c h i l Irong nude t h i l ciia c i c chiing vl slnh vflt
Nude thdi kh&ng xii ly
Nude thii xi> ly vdl cic vl sinh v$t sau 72 gid ChCing SHX. 12
Chung SHV. 22 Chiing SHV. 0A7 (•): khing x6c dtnh
N h i m ddnh gid khd ndng t u o n g tdc da cdc VSV trong d i l u ki^n to hgp, d i tdi danh gid khd nang t6n tgi cOa c ^ c VSV trfin n i n flian bCin khir tning vd hogt Unh sinh hgc cua chung Irong cdc d i l u ki$n rifing Ifi vd t i h g p . K i t qud dug'c Irlnh bdy trong Bdng 3 cho t h i y m | t dfl cdc chOng vl slnh v | t l y a chgn trong d i l u l<i§n hSn hgp v d ridng Id khflng c 6 sg sai khdc. sau 11hdng bdo qudn m$t dfl t l bdo tang nhg sau do giam Vd i n djnh vd dgt mgt dfl > 10® CFU/g s a u 3 thSng bdo qudn, k i l qud k i i m tra cflng xdc djnh hogt tinh sinh hgc cua ede VSV trong d i l u kign to h g p khflng cfl s y sai k h d c s o v d i Chung g i c .
Cdc VSV nghifin cuu d u g c ^ n h danh trfin c a s d gldl trinh V bo^" gen ma hfla 16s ARN riboxom v d s o sdnh v d i cdc trinh Xg ddng k;^ trong ngdn hdng gen q u i c t i EMBL bdng p h l n m i m FASTA 33 Kfit qud xdc dinh cdc chOng VSV nghifin ciru ky hifiu SHX.12. SHV.22 va SHV.0A7 cfl dfl l u o n g d i n g cao v d i S^eptomyces fradiae, Badllus velezensis vd Nilmsomonas sp. Ofli c h i l u vdi danh myc cac VSV khflng bi hgn chl.5i> dgng cCia Cflng d i n g chdu A u , d l tai xdc- dinh cdc VSV l y a chgn thuflc nhfim an todn d p dfl 2. K i t qud nghien CLFU d u g c tong h g p trong Bdng 4 .
B i n g 3. K h i nang song sol va ho^l Unh sinh h9C cua e i e chiing vl slnh vflt trong flilu k i f n tS hgp v i riSng le Kyhieu Cflng thic Bir M|t dQ vi slnh v j t sau thdi gian bao qudn (CFU/g)
ChOng nghl*m oalA 1 i t , ™ • > « , * . .
SHV.22 Ekm chiing Hdn hg'p Don Chung Hdn tiTp Don chiing Hfin hg'p
4.65 X 10"
4.14x10' 4.45 X 10"
3.46 X 10' 4.43 X 10' 3.75x10'
6,47x10*
5,56x10*
6,74x10*
5,75x10' 8,62 X 10' 4,16x10'
4,50x10°
3,32x10"
5,81 X 10"
4,56x10' 5,87x10' 5,63 X 10*
3,98 X 10^
2.45 X 10"
3.63 X 10°
3.86 X 10"
4.60 x l r f * 3.91 X10*
5 mgfl 4,8 mg/l
SHtKHSfttipC CONC HSH6 SINH HPCJOAtiLQUaa2ai3_
Bang 4. K i t q u i x i e ^ n h STT Ky hifiu chung
1 SHX12 2 SHV.22 3 SHV.OA7
ten v i m tit: d$ an t o i n ciia chiing cae vl slnh v | t Ten xdc ^nh
Streptomyces fradiae Bacillus velezensis . Nitmsomonas.sp
MiJcdpATSH Cip dfi 2 C l p d g 2 Cip dfl 2
Trfin CO s d cac k i l q u i nghifin ei>u v i d i l u kign nhan sinh k h i i VSV tren fliilt bi Ifin men chim vd l y a chgn chat mang Ihich hgp (so iiflu khflng trinh bdy), d i tdi da san x u i t thi> thdnh cong e h i p h i m VSV x u IJ n u d e thai nhd mdy e h i bien Unh bflt s i n vdi tdn MIC - CAS. Kfit qua Wlm tra c h i t l u g r ^ c h l p h i m dugc trinh bdy trong Bdng 5.
Bing 5. Kit q u i k i i m tra c h i t lugng c h i pham MIC-CAS
TT Chiing vl slnh v§t Hogt tlnh sinh hgc Mfit dfi l i bao sau 3 thing bdo quan[CFU/g) 1 Streptomyces Irateae Chuyin hfia e^Iulose, Gnh bflt
2 Badllus velezends Chuyin hfia hgp chit photphat kho tan • 3 Nitmsomonas sp. Chuyen hfia hgp chat chda nlto
K i t qud Bdng 5 cho t h i y e h i p h i m MIC - CAS chi>a cdc chiing VSV cfl m§t dfl t i bdo dgt £ 10* CFU/g sau 3 thdng bdo qudn, ddp <>ng yfiu d u v i sdn x u l l c h i p h i m vi sinh v ^ t
Hlfu qui ciJa chi phim vi sinh vft trong xi> l;^ nubc thil sau dii bien tinh bft sin
Thi ngW$m M > i^ nubc ttidi nhd mdy c h l b i i n tinh bgt s i n qui mfl phfing flit nghiflm d u g c Uiuc hifin trfin h# ttiing x u ly gldn dogn quy mfl 80 l(l/me. K i t qud xO ly t i n g hgp trong Bdng 6 cho t h i y vigc b l sung e h i phdm MIC - CAS dd c^i ttilfln ro r§t hiflu qud xi> ly c h i t hOu c a bong n u d e thki. Sau 3 ngay xi> 1^ hdm lugng COD, BODs trong nude flidi tinh bflt s i n gidm 76,2%, vd 89,7% so vfli nuflc Uidi trudc x u ty.
Bing 6. m ^ q u i xir iy nude Uiil chd b l i n Unh b?! s i n cua e h i p h i m MIC - CAS b qui md 80 lit COng thdo thf
nghidm Khfing bfi sung chfi phim CA bfi sung c h i phSm
COD (mg/llt) Ogid
347,6 347,6
N g i y 1 342,5 274,9
Ngdy 2 315,6 191,8
Ngiy 3 301,2 82,9
T7 lfl giim COO sau 3 nF)dy(%)
13.4 76.2
BODs(mq/l) Ogid
281.5 231.5
Ngdyl 272,6 219.2
Ngdy 2 261.3 136.6
Ngay 3 244,8 28,9
Ti Ifi glim BODs sau 3 13.1 89.7 ThO- nghiflm hi§u lye c h i p h i m MIC - CAS d u g c fliyc hign trong hfl ttiong XLP I^ lifin tgc qui mfi 200 lit vfin 8 g i d luu nufl'C flidi vd si> dyng bfl k h u i y lua bin 2 t i n g , v | n toe 150 vflng/phiit Hfl Uiing d u g c v | n hdnh fl-ong 14 ngdy, vfli 7 ngdy d l u Id hogt hfia hfl t h i n g . Ti> ngdy xO- ij thu 81)11 dau I l y mau phan Uch 1 lin/ngdy. K i t qua phdn tich nufl'C ttiai sau 14 ngdy xO" li' dugc tong-hgp fl-ong Bdng 7, xdc djnh nghiflm fliuc s u dgng e h i p h i m VSV cdc thfing s6 BODs, COD dgt qui c h u i n Vifit Nam 40:2011/BTNMT.
Bing 7. Kfit q u i p h i n Uch c h i t lugng nude sau x d i;^ l i i n tyc qui ni& 200 III vfii c h l phim MIC - CAS D l u v i o Qiu ra khdng che phim Oau ra cd chl phim QCVN40;2011/BTNWr COO (mg/I)
B0D5(mg/l) TSS (mgfl) N.(mg/I) P»(nigfl)
318,3 230,5 260.2 41,2 11,9
301,6 236,4 253,2 27,9 7.6
67,3 27,2 22.1 3,1 2.2
Si> dung c h l p h i m MIC - CAS x u 1;^ n u d e thai cOa nhd mdy Unh bflt sdn EL^4AC0 Nmh Binh d u g c thye hifln trong ttidi gian tir Uidng 9 nam 2011 d i n ttidng 4 ndm 2012. K i t qud phdn tich d i l t l u g n g nude flidi cua nhd may cho flidy bo sung c h i pham MIC - CAS dd cdi ttii$n d u g e e h i l l u o n g n u d e thai d l u ra (Bdng 8). Nude thdi nhd mdy c h l b i i n tinh bflt s i n ELMACO Ninh Blnh sau xir ij 6k ddp iJng yfiu c l u ttieo QCVN 40.2011/BTNMT (cflt A)\k dC d i i u kifln ttiai ra tJfi Ihflng nude thdi cflng cflng.
Bing 8. Hi#u qud xir ly ntrdc t h i l nh^ m i y tlnh bot san ELMACO Nfnh Blnh bang che phim MIC-CAS
Chi tifiu phdn Uch Trudc Biogas QCVN 40:2011/BTNMT
COD (mgfl) BODs(mgfl) TSS(mgfl) ' TDS(mgfl)
13800 6200
HOI NGH! KHOA HQC C O N G N G H $ SINH HQC T Q A N Q U 6 C 2 0 1 3
Hinh d n h xi> l y n u d e thai tgi nhd m d y che b i i n t i n h bflt san E L M A C p - N i n h B i n h
K^T LUAN
C h i p h i m vi sinh v^t MIC - CAS x u ly nude ttidi nhd mdy c h i b i l n flnh bflt s i n Id t l h g p g i m chflng Streptomyces fradiae c h u y i n hfla cellulose. Unh bflt. Bacillus velezensis c h u y i n hfla hgp c h i t photphat khfl tan v d Nitrosomonas sp c h u y i n hfla hgp c h i t chda nilo. Si> dgng c h i p h i m MIC - CAS trong xi> i-j gidn do?n nubc thdi sau chfi bifin t m h bflt s i n xdc djnh chl s l COD. BODs giam 76.2% vd 89.7% so v d i d l i ehiing. Nufl'C thai sau c h l b i l n tinh bflt sdn d i | g c bfl sung c h l p h i m MIC - CAS x u 1^ lifln tyc flong hfl ttiing si> dyng bfl k h u i y lua bin 2 t i n g sau 14-ngdy dgt qui c h u S n Wflt Nam 40:2011/BTNMT v i chi s l COD, BODs- O'ng dyng c h l p h i m MIC - CAS Uxing xi> l# n u d e ttidi tgi nhd mdy c h d bien tinh bflt s i n ELMACO Ninh Blnh xdc dinh nude thdi sau xir I'} 6k ddp l i n g yfiu c i u ttieo QCVN 40:2011/BTNMT (cflt A) vd dli d i l u k i | n Hidi ra hfl t h i n g nude flidl cfing eflng.
T A I L l f u THAM K H A O
Nguyfin Lin DOng (ngudi dich), Egorov N.X: (1976) Tfii/c t$p vi slnh vd hgc. NXB Mir, Maxcova vd d^l hgc THON, IHd Nfli.
Quyfin Olnh Thi (2005) Cflng nghfi sinh hoc tfip 1, NhOng ky thuft co tiin trong phfin tlch DNA. NXB Khoa hgc kJ Uiu^l TCVN 4556-88, Nude Ihil-phuong phip l i y mlu, vfin chuyfin v i b i o quin m l u
TCVN 6491:1999 (ISO 6060:1989): C h i l lugng nude-Xic djnh nhu d u oxy hfia hoc TCVN 5987:1995 Chit lugng nude-Xic dinh Nilcr-Kjeldahl
TCVN 6202 2008 (ISO 6878.2004) C h i l lugng nude- Xic djnh Phospho, Phucmg phip i r i c p h i diing Amoni molipdat TCVN 6625 2000 (IS011923.1997) C h i l lugng nude- Xic djnh chit rfin lo ICrng bing cdch Igc qua c i i lipc sgi thdy tlnh.
TCVN 6001.1995 Chfit Iirgng nude- Xic dinh nhu ciu oxy sinh hda sau 5 ngiy (BODs)
Tmng t i m sin xuit sgch Vifit Nam (2009): T i i lifiu hudng d i n sdn x u i l sgch hon nginh sdn xuit tinh b^t s i n .
Sambrook J, Russell DW. (2001) Molecular Cloning. A Laboratory Manual, 3 rd ed. Cold Spring Hartror Laboratory, Cdd Spring harbor.
IMPROVING THE QUALITY OF WASTEWATER FROM CASSAVA STARCH PROCESSING USING THE BIO-INOCULANT
Vu Thuy Nga', Luong Huu Thanh', Pham Van Toan'
%sBtute for Agncultural Environment, Vietnam Academy of Agricultural Sciences- Vietnam Academy of Agricultural Sciences
SUMMARY
Waste water of processing cassava starch was known a source of environmental pollution. Most of cassava starch processing factories have wastewater ireatmenl system, bul due lo many different causes, the treatmenl was unsalis&ciory. In order to redress ihe sewage contamination of cassava starch processing, the study focused on the selection of the microorganism wilh high biological activities for production and application microbial inoculants to improve efficiency of wastewater after biogas treatmenl. T h e ohtabed results showed fliat 3 strains including 5oc(7/ia velezensis, Streptomyces fradiae and Nilromonas sp. have good ability to metaholue organic compounds m waste water of cassava starch processing. The MIC - CAS inoculant made from 3 selected strains was reduced 76.2% (COD) and 89.7%''(BODj) m wastewater after 3 days of treatment, Apphcation the bio-noculant in wastewater treatment system at EI-MACO Ninh Binh factory deterrained wastewater quality after treatment ensured regularization n u m b e r 40-2011 or Vietnam's Mmistry of Natural Resources and Environment (column A) arui eligible for discbarge.
Keywords- Cassava starch processing, microbial inocuiant, metabolize organic compounds, wastewater, treatment _.
-Author for correspondence. Tel. •84-4-37893776; Email" [email protected]
