~ TAP c m SINH HOC 2013, 35(4): 454-460
V I K H U A N T A O C H A T H O A T H O A B E M A T S I N H H O C Rhodococcus ruber T D 2 P H A N L A P T i r N U " 6 C 6 N H I E M D A U V E N B T E N V U N G T A U
L a i Thiiy H i l n * , Nguyen T h i Yen, VuoTig T h i N g a
Vien Cong nghe sinh hoc, Vien Han Lam K H va CN Viet Nam, *[email protected] TOM TAT: Chdt boat hoa bg mat sinh hgc (CHHBMSH) duoc t6ng hgp chii yeu bdi vi khuan thuoc chi Rhodococcus thudng la glycolipids, trehalose lipids. Vdi cac uu diem vugt troi hon so vdi CHHBM hoa hgc va CHHBMSH tir vi sinh vat khac, thg gioi da co nhiSu nghien ciiu ve CHHBMSH tir chi nay nham ling dung trong cac lmh vuc cong nghe mdi nhu xu ly moi tnidng, cai thien cau Inic vat lieu polymer va y hgc, Chiing vi khuin TD2 phan lap ttr nudc bign nhilm diu Vung Tau co kha nang tao chat hoat hoa be mat sinh hgc. Chiing vi khuan TD2 co te bao hinh que, thugc nhom vi khuan gram duong, khong tao bao tli. Phan !oai chiing vi khuan TD2 bang phuong phap phan tich trinh tu gen 16S-rRNA xac djnh chung vi khuan nay tucmg dong 100% vdi loai Rhodococcus ruber. Nghien ciiru cac yeu td moi truong anh hudng den qua trinh sinh tnrong va tao CHHBMSH cho thay chung TD2 tao CHHBMSH cao a dieu kien phu hgp vdi nhiet do SCC, pH 8-9, nong do NaCI 1-2%, nguon carbon la dau oliu, chi so nhii hoa E24 dat 94%. Tren moi trucmg nuoi cay phii hgp da xac dmh tren, ham luong CHHBMSH tho do TD2 tao ra la 13,7 g/1, Kgt qua phan tich bing GC-MS cho thiy, CHHBMSH do chiing TD2 tao ra la ester cua acid beo Hexadecenoic hoac Hexanedioic acid bis 2-ethylhexyi vdi cau tnic phan tir gom nhieu nhom —OH va C=0.
Tie khoa Rhodococcus ruber, acid beo, chat hoat hoa be mat sinh hoc. chi so nhu hoa E24, dau oliu MCfDAU
Chat boat hoa be mat smh hgc (CHHBMSH) la nhirng hgp chat cd cau tnic da dang ve hoat tinh bg mat dugc tong hgp boi vi smh vat. TSt ca C H H B M S H la hgp c h i t luang cue, CO cau tao gom mgt nhdm ua nudc (thudng la phan tir duong hoac amino acid) va mgt nhom ki nudc (thuong la acid beo). Do cau tao phan cue, C H H B M S H co xu hudng co cum tai be mat va mat phan each giua 2 chat (co the la chat long-chat Idng, chat long-chat ran), ket qua la lam giam siic cang bg mat (giua chat long va khdng khi) va giam siic cang giua 2 chat (chit long-chit long va chat long-chit r i n ) [12, 13].
Khong gidng nhu C H H B M H H thudng phan loai theo ban chat cac nhom phan cue, CHHBMSH d u a c phan Ioai dua vao thanh p h i n hoa hgc va nguon goc vi sinh vat tao ra. Nhin chung, C H H B M S H dugc chia lam cac n h o m chinh: glycoHpid; lipopeptid va lipoprotein;
phospholipid va acid beo; C H H B M trimg hgp va CHHBM dang hat [2].
C H H B M S H do loai Rhodococcus ruber tao ra chli ygu la dich ngoai bao trgn ngudn c a c h i t hydrocarbon. Chiing thugc n h o m glycolipid cd chiia goc trehalose n h u la carbonhydrat. Vai tro
ciia glycolipid rat da dang, tir viec thiic day su bam cua tg bao vao be mat ki n u d c ciia co chat khong tan trong nudc, tdi viec lam tang kha nang d e khang cua vi khuan doi vdi cac ygu to ly hoa ciia moi t r u d n g . . . [ 6 , 1 2 , 13]. Hon niia, glycolipid tit Rhodococcus u n viet ban so voi C H H B M tdng hgp ciing nhu C H H B M S H hi cac vi sinh vat khac bdi cac dac tinh n h u siic cang be mat, kha nang nhii hoa cao, tinh khang khuan va dieu chinh mien dich [13]. Vdi cac dac tinh u u vigt do, C H H B M S H tir Rhodococcus ngay cang d u g c nghien ciiu va img dung trong nhieu ngatih cdng nghiep dac biet la cdng nghiep dau khi va xii ly moi trudng. Trong bai bao nay, chimg toi de cap dgn dac diem sinh bgc vit kha nang tao C H H B M S H cua chiing Rhodococcus ruber T D 2 phan lap tir bai bien Thiiy Ducmg, Viing Tau, nham dua ra c a s o dii lieu dg dmh h u a n g ling dung chiing T D 2 trong xii ly 6 nhiem dau ven bign Viet N a m .
VAT LIEU VA PHirOfNG PHAP NGHIEN ClTU V a t lieu va moi tru-ong n u o i cay
_ Cac mau nudc bign n h i l m d i u l i y tai ven bien Viing Tau, Viet N a m .
Sii dung mdi truong khoang Gost 9023-74
Lai Thuy Hien, Nguyen Thi Yen, Vuong Thi Nga bo sung 5 % dau diezel (DO) d e phan lap va
nghign cuu kha nang tao C H H B M S H ciia vi khuan. Mdi trudng hieu khi tong sd 1% NaCI (HKTS1%) (API RP38) dg quan sat hinh thai khuan lac chiing nghien ciiu.
Phuong p h a p
Phan lap vi khuan tao C H H B S M H tren mdi trucmg khoang Gost 9023-74.
Nghign cim hinh thai te bao vi khuan dudi kinh hign vi dien tii SEM S4800 (Nhat Ban) tai phdng Hign vi dign tit, vien Ve sinh Dich te Trung uang.
Danh gia kha nang tao C H H B M S H dua tren chi s6 nhu hoa E24 (Pruthi) [15].
Phan loai vi khuan dua vao phan ticb trinh tugen 16SrRNA.
Tach chigt C H H B M S H theo Kuyukina [11]
Phan tich thanh phan hda hgc ciia CHHBMSH b i n g s i c ki khoi pho GC-MS tai vien Cong nghe mdi trudng, vign Han lam khoa hpc va Cdng nghe Viet Nam.
KET QUA VA THAO L U ^ N
Dac diem p h a n Ioai va k h a n a n g tao C H H B M S H cua c h u n g T D 2
Tir cac mau nutjc 6 nhigm dau \ ^ n bign Vung Tau, chiing toi tien hanh phan lap vi khuan cd kha nang tao C H H B M S H trgn mdi trudng chgn Igc. Sau do, danh gia kha nang tag C H H B M S H ciia chiing bang chi so nhii hoa E24 Kgt qua, da phan lap dugc chiing vi khuan TD2 CO kha nang tao C H H B M S H cao va chiem u u the d hau het cac mau. Dac diem khuan lac, hinh thai tg bao, chi so nhu hoa E24 ciia chiing nay dugc trinh bay d bang 1, hinh 1 va 2,
Bdng 1. Dac digm khuan lac, tg bao va kha nang nhii hoa vdi xylen ciia chimg T D 2
KH chimg
TD2
Dac digm hinh thai khuan lac Vang cam, tron loi, bdng udt, mep ggn, d ^ 1,5-2,0 mm
Dac diem te bao Que ngan, Gram (+), khong
sinb bao tir
E24 65%
Theo nhigu nghign cim trong va ngoai nudc.
vi khuan bien tao C H H B M S H thuang gap la thugc nhdm vi khuan gram am nhu Pseudomonas, Acinetobacter [2, 8, 9, 10, 15].
Tuy nhien, d viing bien Viing Tau, noi thudng xay ra cac dgt d nhiem dau ven bien thi cac chiing vi khuan gram duong, nhu chimg TD2 lai chigm uu thg. Day cd thg do qua trinh chpn Igc tir nhien vdi cac vi khuan d nhung viing d
nhicm dau Dg xac djnh vj tri phan loai chimg nay nham cung cap dii lieu ve vi khuan tao CHHBMSH phan lap tai ven bien Vigt Nam, trinh tu 16S rDNA cua chiing T D 2 dugc phan tich. Khi so sanh vciti ngan hang dii lieu gen chuan cho thay, trinh tu I6S rDNA ciia chiing TD2 tuong ddng 100% vdi trinh tu 16S rDNA ciia loai Rhodococcus ruber X 80625 (hinh 3).
Hinh 1. Hinh thai khuan lac chiing TD2 tren moi trudng H K T S I %
Hinh 2 Hinh thai te bao chung TD2 dudi kinh HVDT quet (SEM 48001
TAP CHI SINH HQC 2013, 35(4) 454-460 Rhodococcus ruber la mgt trong
nhirng chung vi khuan cd kha nang tao C H H B M S H d u g c nghign ciiu nhieu trgn the gidi [4, 5, 13]. O Viet Nam, day la cdng bd dau tien vg kha nang tao C H H B M S H cua loai vi khuan nay.
Anh huoTig ciia mot so yeu to moi tru-cmg d e n sinh t r u d n g v a t a o C H H B M S H ciia chiing T D 2
6 digu kien thi nghiem, kha nang nhu hoa vdi xylen cua C H H B M S H do T D 2 tao ra kha cao (65%). Tuy nhien, dg irng dung C H H B M S H do chiing nay tao ra can phai nghign ctiu cac yeu to mdi trudng den sinh trudng va kha nang tao C H H B M S H . Trong cong trinh nay, anh hudng ciia nhiet do, pH, nguon carbon va ndng do NaCI tdi sinh trudng va kha nang tao C H H B M S H ciia chiing T D 2 da d u g c nghien CIJU.
Hinh 3. Vi tri phan loai ciia chiing TD2, va cac loai co hg himg g i n
Anh hudng cua nhiet dp C H H B M S H ciia vi khuan [4]. Nhiet do lua chgn de nghign ciiu sinh t r u d n g va tao C H H B M S H Nhiet dg mdi trudng nudi cay cd t h i ciia chiing T D 2 la 2 0 , 30, 37 va 42''C. Ket qua anh hudng den kha nang sinh tong hgp dugc the hien 6 hinh 4.
Hinh 4. Anh h u d n g ciia nhiet d o den sinh truong va tao C H H B M S H cua chiing T D 2
Lai Thuy Hien. Nguyen Thi Yen. Vuong Thi Nga Nhu vay, chiing T D 2 sinh t m o n g tdt va tao
CHHBMSH cao trong khoang nhiet d o tir 20 den 37''C vdi chi sd nhii hoa E24 dao dgng 70- 85% sau 5 ngay nuoi cay. Trong dd, nhiet do tdi uu cho qua trinh sinh tong hgp C H H B M S H ciia chung nay la 30''C, chi sd nhii hda E24 dat 8 5 % sau 5 ngay. Theo cac cong bo d trong va ngoai nudc, day cung la nhiet do thich hgp cho qua trinh sinh tong hop C H H B M S H bdi vi khuan [4, 9, 10]. CJ nhiet do 4 2 ^ , T D 2 sinh trudng kem hon vdi chi sd nhu hda E24 chi dat 3 0 % sau 5 ngay nudi cay.
Anh hud'ng cua ngudn carbon
Nguon carbon khac nhau cd anh hudng Idn dgn kha nang tao C H H B M S H ciia vi khuan ciing nhu thanh phan cau tao ciia CHHBMSH tao thanh [3,4]. Ngudn carbon su dung cho vi khuan sinh tdng hap C H H B M S H bao gdm carbohydrate (glycerol, cac loai dudng...), hydrocarbon va dau thuc vat. Mdt sd loai vi
khuan chi sir dung mgt loai carbon cho sinh tdng hgp C H H B M S H , mpt sd khac cd thg sir dung ca ba ngudn carbon kg tren [3, 7, 15]. Sinh truong va kha nang tao C H H B M S H cua chiing T D 2 dugc khao sat tai cac ngudn carbon:
glycerol, ri dudng, D O va dau oliu. Ket qua the hien d h i n h 5.
Nhu vay, chung T D 2 cd kha nang sinh tnrdng va tao C H H B M S H trgn cac ngudn carbon la dau oliu, D O va ri dudng. Trong dd, dau oliu la ngudn carbon thich hgp nhat cho sinb trudng va tao C H H B M S H ciia chiing nay, chi so nhu hda E24 dat 9 4 % sau 5 ngay nudi cay. Vdi ngudn carbon la DO va ri dudng, chiing nay cung cho thay kha nang sinh trudng kha tdt vdi chi sd do dugc E24 lin luot dat 89 va 72%i Tuy nhien, T D 2 khdng sinh trudng va tao C H H B M S H tren ngudn carbon la glycerol.
Dieu nay khac biet so vdi cac chiing Rhodococcuss da d u a c nghign cim trgn the gidi [3, 4].
Hinh 5 Anh hudng cua ngudn carbon den sinh trudng va tao C H H B M S H chung TD2
Hinh 6. Anh hudng ciia pH den sinh tnrdng va tao C H H B M S H chiing T D 2 Anh h v a n g cua p H
Sinh trudng cua vi khuan bi tac dgng manh bdi pH moi trudng nuoi cay, do dd se anh hudng true tigp den qua trinh sinh tdng hgp CHHBMSH. De nghien ciiu su tac dgng nay, sinh trudng va kha nang tag C H H B M S H ciia TD2 dugc khao sat d dai pH tir 5 dgn 9 trong 8 ngay nuoi cay (hinh 6).
Ket qua cho thay, chung T D 2 sinh trudng va t?o CHHBMSH tot 6 dai pH tii 5 d i n 9, tdt nhit a pH kiem (8-9). Tai dai pH nay, chi sd nhii hoa E24 do dugc lan lugt la 92 va 90%. sau 5 ngay nuoi cay. So vdi cac nghign ciiu ciia cac tac gia tren the gidi v l pH ihi'ch hgp cho sinh tong hgp
CHHBMSH ciia chi Rhodococcus la 6,8-7,0 [1, 5], thi chiing T D 2 cd kha nang sinh trudng va tao CHHBMSH trong dai pH kha rgng. Day se la yeu td thuan loi dg irng dung chiing nay trong qua trinh phan huy dau ven bien Viet Nam.
Anh h u o n g ciia n o n g d o NaCI
Ndng do muoi ciing la ygu td anh hudng dgn tinh c h i t ciia CHHBMSH do vi khuan tag ra [14]. Anh hudng ciia ndng dp mudi NaCI dgn smh tnidng va tao C H H B M S H ciia chiing TD2 dugc nghien ciiu vdi cac ndng dg 0, I, 2. 3 va 4%) trong 8 ngay nudi cay (hinh 7). Ket qua cho diiy, chiing TD2 cd kha nang tao C H H B M S H d tat ca ndng do NaCI khao sat. Tuy nhign, chiing
TAP CHI SINH HOC 2013, 35(4): 454-460 nay sinh trudng tdt nhat va tao CHHBMSH cao
nhit d ndng do NaCI tii 1 -2% vdi chi sd E24 lgn tdi 92-93%i. Ket qua thu dugc cung tucmg ddng vdi nghign ciiu cua Chenggang et al. (2009)
[4]. Tac gia da xac dinh dugc nong do NaCI tdi mi cho kha nang tao CHHBMSH ciia chiing Rhodococcus ruber Z25 la 2%.
M\\ « 1
Hinh 7. Anh huong ciia ndng do NaCI tdi sinh trudng va tao CHHBMSH chung TD2 Ham luo'ng va thanh phan cua CHHBMSH do chiing TD2 tao ra
Chiing TD2 dugc nudi lac tren mdi trudng vdi nhung yeu to phii hgp nhu ngudn co chat la dau oliu, nhiet do 30''C, pH 8-9, va ndng dp NaCI 1-2% dg thu hoi CHHBMSH. Kit qua cho thiy, CHHBMSH thd do chung TD2 taora dat ham lugng 13,7 g/l. Theo cdng bd ciia Chenggang Zheng et al. (2009) [4], cbiing Rhodococcus ruber Z25 phan lap tir nudc nhigm dau cd kha nang sinh tdng hgp 13,3 g/l CHHBMSH tho trgn nguon co chat alkane.
Ham lugng dau thd tao ra tir cbiing TD2 khdng cao hon nhigu so vdi chung Z25, tuy nhien, day la ket qua nghien ciiu dau tien ve kha nang tao CHHBMSH cua chung Rhodococcus ruber phan lap tai Viet Nam. Vi vay, can tiep tuc nghign ciiu tdi uu hda cac yeu td anh hudng den
Hinh 8. Sic ky khoi phd cua CHHBMSH do ^ chung vi khuan TD2 tao ra
qua trinh tao CHHBMSH nham lira chgn mdi trudng tdi uu cho chiing nay tao CHHBMSH cao hon. Dg iing dung bieu qua CHHBMSH do timg loai vi sinh vat tao ra thi viec tim hieu cau tnic hda hoc ciia chiing ddng vai trd rat quan trgng. Bigt dugc cau tnic hda hoc ciia CHHBMSH se gnip du doan co che tac dgng cua chiing trong viec tang cudng kha nang phan huy hydrocarbon dau md, xir ly 6 nhiem mdi trudng. CHHBMSH do TD2 tao ra dugc phan tich sac ky khdi phd (GS-MS) dg tim hieu ban chat hda hgc cua chiing.
Kgt qua phan ticb GC-MS (hinh 8) cho thiy, cd 13 phan doan trong CHHBMSH tho, tuy nhien, chi cd hai phan doan a thai gian luu la 21,127 phiit va 23, 337 phiit cd cau tnic tuong tu CHHBMSH hgc chuan.
MH.rl..i.|...j.,.>.T...'^^ O i i ^
Hinh 9. Khdi phd CHHBMSH do chung TD2 tao ra tai thdi gian luu 23,337 va 21,127 phut
Lai Thuy Hien, Nguyen Thi Yen, Vuong Thi Nga Phan tich phan doan co thoi gian luu 21,127
phiit cho thay, chat nay cd chiia cac nhdm nguygn td cd trgng lugng phan tu (m/z) tuong ling: 4 1 ; 55; 69; 83; 97; 111; 123; 151; 180;
222. 264 va 282 (hinh 9), So sanh vdi thu vien chat chuan, chat nay la acid beo Hexadecenoic acid (C|fiH3o02) vdi d o tuong ddng 90%.
Tai phan doan cd thai gian luu 23,337 phut, CHHBMSH CO chiia cac nhdm nguygn td cd trong lugng phan tii (m/z) tuong iing: 57; 70;
83; 112; 129; 147; 207 va 241 (hinh 9). Miic dp tugng ddng ciia chat nay so vtiri Hexanedioic acid bis 2-ethyIhexyl (C22H^204) ia 9 4 % khi so sanh vdl thu vien chat chuan. Tir ket qua phan tich GC-MS, cd the nhan dmh C H H B M S H do chiing TD2 tao ra la ester cua acid Hexadecenoic hoac Hexanedioic bis 2- ethylhexyl vdi can tnic phan tii gdm nhieu n h 6 m - 0 H v a C = 0 .
Da phan lap duoc chimg vi khuan Rhodoccocus ruber T D 2 (tucmg ddng chiing chuan Rhodococcus ruber X 80625 100%,) cd kha nang tao C H H B M S H tir cac mau nudc 6 nhiem dau ven bien Vung Tau Dicu kien tdi uu dc tao CHHBMSH cua cbiing nay la nhigt do 3 0 T , pH 8-9, ndng dp NaCI tir 1-2%, sii dung ngudn carbon la dau oliu, chi sd nhii hda E24 dat 94%, ham lugng C H H B M S H thd la 13,7g/l.
CHHBMSH do chiing T D 2 tao ra cd kha nang boat dgng be mat va la ester ciia acid beo mach dai Hexadecenoic (C16H30O2) hoac Hexanedioic acid bis 2-ethylhexyl (C22H42O.,) vdi nhilu n h o m - O H va C = 0 trong cau tnic phan ni.
Ldi c a m o n : Cong trinh nay dugc thuc hien vdi su hd trg vg kinh phi ciia dg tai Dgc lap cap Nha nudc ma s6 D T D L 2008 T.02. Cac tac gia cam an su cgng tac giiip dd ciia Phdng Hign vi dign tli, Vien Ve sinh Dich te Trung uong; Vign Vi sinh vat va Cong nghg sinh bgc, Dai hgc Quoc gia Hii Ngi; Vien Cdng nghe mdi trudng, Vign Hiin liim Khoa hgc va Cdng nghe Vigt Nam
TAUIEU THAM KHAO
t. Abu-Ruwaida A. S., Banat I. M., Hadituto S„ Khamis A., 1991. Nuttitional
requirements and growth characteristics of a biosurfactant-producing Rhodococcus bacterium. World J. Microbiol. Biotechnol., 7(1); 53-60.
2. Banat M. I., Franzetti A , Gandolfi A., Bestetti G., 2010. Microbial biosufactants production, applications and future potential. Appl. Microbiol. Biotechnol., 87:
427-444.
3. Ciapina E. M., Melo W. C , Santa Anna L, M „ Santos A. S., Freire D. M., Pereira N . Jr., 2006. Biosurfactant production by Rhodococcus erylhropolis grown on glycerol as sole carbon source Appl.
Biochem. Biotechnol, (1-3). 880-886.
4 Chenggang Z., Shuguang L., Li Y,, Lixin H., Qinghong W., 2009. Smdy of the biosurfactant-producing profile in a newly isolated Rhodococcus ruber stram. Ann.
Microbiol., 59 (4): 771-776.
5. Flavio C, B,, Leonardo C, F,, Marco A. Z.
A,, 1999 Production of biosurfactant by hydrocarbon degrading Rhodococcus ruber and Rhodococcus erylhropolis. Revista Microbiol., 30: 231-236.
6. Franzetti A., Gandolfi I. Bestetti G., Smyth T J., Banat I M . 2010. Production and applications of trehalose lipid biosufactants.
Eur J Lipid- Sci Tech . 112. 617-627.
7. Hamzah A., Sabturani N., Radiman S , 2013. Screening and optimization of biosurfactant production by the hydrocarbon-degrading bacteria. Sains Malaysiana, 42(5): 615-623.
8. Lai Thiiy Hien, Do Thu Phuong, Hoimg Hai, Pham Thi Hang, Le Tbi Nhi Cdng, Le Phi Nga, Kieu Hiru Anh, 2003. Chon chiing vi sinh vat tao C H H B M S H cao ling dung trong cdng ngbiep dau khi vii xir ly mdi trucmg. Tap chi Cdng nghg sinh hgc, 1: 119- 129.
9. Lai Thuy Hign, D u a n g Van Thang, Tran c i m Van, Doan Thai Hoa, 2003. Vi khuin tao c h i t boat hoa be mat sinh hgc phan lap tir bien Nha Trang. Tap chi Sinh hoc, 25(4):
53-61.
TAP CHI SINH HOC 2013, 35(4): 454-460 10. Lai Thiiy Hicn, N g u y i n Thi Thu H u y i n , D o appUcations of biosurfactants: Recent
Thu Phuong, P h a m Thi H5ng, K i l u Quynh Advances. Int. J. Mol. Sci., 12: 633-654.
Hoa, Vucmg Thj Nga, Nguyen Thj Yen, ] 3 . Maria S. K. and Irena B. I., 2010.
Hoang Van ThSng, Tran Dinli Man, 2011. Rhodococcus biosurfactants: Biosynthesis, Nghien cmi da dang vi khuan bien tao chat Properties and Potential Application. Bio.
boat boa b e mat smh hoc nham ling dung Rhodococcus, 16: 291-313.
trong cong nghicp va xii ly 6 n h i l m moi j ^ Mancerat S., Phectrong K , 2007. Isolation tniong Hoi ngh| Khoa hoc va Cong nghe ^^ biosurfactant-producing marine bacteria bien toan quoc, 5: 297-305. ^^^ characteristics of selected biosurfactant.
11. Kuyukina M . S., Ivshina T, Philip J., Songklanakarin J. Sci. Technol., 29(3): 781- Christofi N., Dunbar S., Ritcbkava M., 791
2001. Recovery of Rhodococcus jg p ^ t ^ i V., Cameotra S. S., 1997. Rapid biosurfactants using methyl tert^^^-butyt .^entification of biosurfactant-producing etherextraction J. Microbiol, 46: 149-156. ^^^^^^.^^ ^^^^-^^ ^^-^^ ^ ^^,1 ^^^^^^^
12. Magdalena P. P., Grazyna A. P., Zofia P. S., bydrophobicity technique. Biotechnol.
Swaranjit S. C , 2011. Environmental Techniques, 11(9): 671-674
B I O S U R F A C T A N T - P R O D U C I N G Rhodococcus ruber T D 2 I S O L A T E D F R O M O I L P O L U T E D W A T E R I N V U N G T A U C O A S T A L Z O N E
L a i T h u y H i e n , Nguyen T h i Yen, V u o n g T h i N g a Institute ofBiotechnology, VAST
SUMMARY
Thanks to their advantages compared with other microbial and synthetic surfactants, Rhodococcus biosurfactants are widely studied to apply in new advanced technologies, such as environmental bioremediation, improved polymeric material construction and biomedicine. A biosurfactant-producing strain TD2 was isolated from the oil poluted water at Vung Tau coastal zone. Strain TD2 was observed as rod- shaped, positive gram, non-spore bactenum. The strain was identified as Rhodococcus ruber TD2(I00%
identity Rhodococcus ruber X 80625) based on 16S rDNA analysis. Investigation of influence of environmental conditions on cell growth and biosurfactant production showed that strain TD2 produced highest biosurfactant at SCC, pH 8-9, 1-2% NaCl (w/v) and olive oil as carbon source In this condition, Rhodococcus ruber TD2 exhibited to be a potential producer attaining 94% of emulsifying index £24 and the maximum yield of crude biosurfactant production was 13.7 g/l GC-MS analysis revealed that biosurfactant of Rhodococcus ruber TD2 was ester of Hexadecenoic acid or Hexanedioic acid bis 2-ethylhexyl containing of many -OH and C = 0 groups in structural chemicals
Keywords: Rhodococcus ruber, biosurfactant, emulsification index E24. olive oil, fatty acid.
Ngay nhdn bii: 25-6-20] 3
