NGHIEN CLTU DA DANG QUAN THE VI SINH VAT KHU VlTC BIEN BINH THUAN VA KHA NANG PHAN HUY DAU THO BACH HO CUA CHUNG

Tieu ban: CONG NGHE SINH HQC Bl^N VA M 6 | TRU'ONG 555 NGHIEN CLTU DA DANG QUAN THE VI SINH VAT KHU VlTC BIEN BINH THUAN VA KHA NANG PHAN HUY DAU THO BACH HO CUA CHUNG Lai Thuy Hien',

Tieu ban: CONG NGHE SINH HQC Bl^N VA M 6 | TRU'ONG 555

NGHIEN CLTU DA DANG QUAN THE VI SINH VAT KHU VlTC

BIEN BINH THUAN VA KHA NANG PHAN HUY DAU THO

BACH HO CUA CHUNG

Lai Thuy Hien', Hoang Thj Minh T h a o ^ Do Thu Phuong, Nguyen Ba Tii',

Hoang Van Thang'

' Vien Cong nghe Sinh hpc, Vien Khoa hpc va Cong nghi Viet Nam

^Trung tdm Nghien ciru, Phat triin An todn vd Moi truang Ddu khi, Vien Ddu khi Vi^t Nam

L M O DAU

Trong thai gian vira qua, khu vyc bien Dong Nam Bg nuac ta da xay ra hang loat sy co tran

dau, trong do khu vyc bien Binh Thuan bj anh huang nang ne nhat Tinh Binh Thuan vai ba bien

dai 192km, la nai co vj tri dja ly thuan lgi de phat trien cac nganh kinh te gan vai bien [5] Tuy

nhien do chi each khu vyc tap trung nhieu boat dgng dau khi khoang 60km va nam trong tuyen

hang hai quoc te ket noi Viet Nam vai cac nuac thugc khu vyc Dong A nen noi day luon tiem an

nhieu nguy ca gay sy co tran dau [5]

Hien nay, bien phap sinh hgc la mgt trong nhirng ky thuat co tinh canh tranh nham duy tri

chat lugng moi truang, trong do vi?c ap dung phan buy sinh hgc nha vi sinh vat noi len nhu mgt

giai phap hiru hieu trong xir ly 6 nhiem dau tran va lam sach nuac thai cac nha may lgc dau [1,

2, 7] Uu diem ciia phuong phap nay so vai cac ky thuat khac trong viec lam sach moi truang la

giam gia thanh va tac dgng den hf sinh thai a mire thap nhat [1, 2, 9] Dimg truac cac van de

thyc te do, chung toi tien hanh khao sat, lay mau va phan tich thanh phan, so lugng mgt so nhom

vi sinh vat tai khu vyc bien Binh Thuan bj 6 nhiem do dau tran frong nhiing nam gan day Dong

thofi, buac dau nghien ciru kha nang phan buy mgt so loai dau tho Vift Nam ciia hon hgp chiing

CO mat trong nuac va fram tich tai khu vyc nghien ciru

II VAT LIEU VA PHUONG PHAP

L Pham vi nghien curu

Vimg nghien ciru tir Mui Ne den Lagi - Ham Tan, thugc ven bien tinh Binh Thuan, la viing

biln ha, chju tac dgng manh ciia song Co 10 vj tri thu mau tap trung tai 5 diem: 1) Hon Ram

Mui Ne; 2) Vinh Phan Thilt; 3) Tiln Hai Tiln Thanh Phan Thilt; 4) MQi ke ga; 5) Lagi

-Ham Tan

2 Doi tu-ong nghien ciiru

- M I U nuac dugc lay bang Batometer vai do sau: 4m (tang mat) va 8m (tang giira)

- M I U tram tich dugc lay a do sau 12m bang gau Peterson (M1200-C15 Wildco ciia My)

- Dau tho mo Bach Ho, Vung Tau

556 Tuyen tip Hpi nghj KHOA HQC TOAN QU6c Vg SINH HQC BI^N VA PHAT TRifeN B £ N VQNG

3 Phirong phap

* Dem s6 lugng cac vi sinh vat va phan lap vi khuan hiiu ich, gay hai tren cac moi truang chgn lgc: vi khuin hilu khi (HK) fren moi truang hieu khi tong so, vi khuan len men (LM) tren moi truang MRS, vi khuan khir sunphat (KSF) tren moi truang Postgate B cai tien; vi khuan nifrit boa (NTiH), nifrat hoa (NTaH) tren moi truong Basruda, vi khuan khir nitrat (KN) tren moi truang Giltai, vi khuin sir dung hydrocacbon (SDHC) tren moi truang khoang Gost [9,11]

* Xac djnh cac vj tri liy mau bang thiet bi dinh vi ve tinh GPS Cac thong so hoa ly moi truang do tai cho bing may kiem tra chat lugng nuac 6 chi tieu TOA (Model WQC-22A)

* Nghien curu hinh thai vi sinh vat duai kinh hien vi di?n tir JEM 1010 (Nhat Ban)

* Phan loai cac chiing vi sinh vat dien hinh dya vao dac diem hinh thai va sii dung cac kit chuin sinh boa API ciia hang BioMerieux, Phap:

- API 50 CHL diing cho vi khuan Gram duong khong sinh bao tii

- API 20 rapid E diing cho vi khuan Enterobacter

- API 20 NE diing cho vi khuan thugc nhom Nonenterobacter

* Phuang phap danh gia kha nang phan buy dau:

- Thir nghiem thyc hien theo phuong phap BODIS Marine - dugc cai tien tir tieu chuin ISO TC/147, SC5/WG4 N141 BOD - ap dung cho cac chit khong hoa tan (1995) [6] - nhim xac djnh dau tho nghien cuu co kha nang phan hiiy sinh hgc de dang trong dieu kien hieu khi hay khong

- Kha nang phan ra sinh hgc dugc tinh bang nhu cau oxy sinh hoa (BOD) tich liiy ciing vai nhu cau oxy hoa hgc (COD):

Y^BOD ZBOD = BOD tich lily sau 28 ngay thir nghiem (dan vj mg O2)

wpchat t h u X C O D * COD= Nhu cau oxy boa hgc (don vj mg 02/mg chit thir)

* Phuang phap xac djnh ham lugng dau trong nuac

- Cac mau thir nghiem xac djnh ham lugng dau frong nuac dugc phan tich theo quy trinh

LAI-75-46: 'Xac dinh tong ham luang ddu md trong nuac vd nude thdi bdng phuang phdp khoi luang"

- Nguyen tac: Mau nuac dugc chilt bang dung moi Di-chloromethane (DCM), sau do loai

bo het dung moi, can xac djnh lugng chat thu dugc

m KET QUA VA THAO LUAN

I Mot so dac diem hoa ly ciia nu-oc bien Binh Thuan

Ba bien Binh Thuan co cau triic dia hinh, dja mao phirc tap, tieu bieu la dang ba hon hgp giira cac cung ba bai cat an 15m vao dit liln va cac mui da, ghenh da nho ra biln Phin day bien ven ba tinh tir mep nuac den do sau -20m dgc theo duong ba biln tir mui Ne din Lagi bao gom

2 dai la dai song vo ba va dai song biln dang va pha hiiy, tao trim tich la biin, set lin cat Ba bien viing nghien ciiu thugc loai ba bien bj biln dgng manh bai dgng lyc song va dugc tai tao lai

bai gio Doan ba frr Mui Ne den mui Ke Ga co xu huong phat friln chung la khd Sn dinh fren ca chieu dai doan duang ba khoang 49km Rieng doan ba dilm 5 va 6 co xu huang dip tuc bi xam thuc Ngoai ra, doan ba biln ba phia Tay cira Song Cai (Phan Thilt) va phia Tay mui Ne cung la nhung doan ba co kha nang bj xdm thuc, cin chii y Ba phia Tay mui Ke Ga co xu huang chung la boi tu song tic do khong manh Cau tao bai biln doan nay chu ylu tir cat hat mjn va hat trung

"Tieu ban: CONG NGHE SINH HOC B I ^ N VA MOI TRLTONG 557

Doan ba mui Ke Ga den Lagi co xu huong khong on dinh trong tuong lai vai chieu dai den ban

20km

Chat lugng nuac bien ven ba theo so lieu khao sat cho thay pH nam trong khoang 7.3 - 8.0; nhiet do nuac bien dao dgng trong khoang 28°C tai thai diem liy miu; Chi s6 DO dao dgng trong khoang 4.13 - 5.96mg/l, nhu vay qua trinh quang hgp cap oxy khong Ion; Dg man nuac bien dao dgng tir 21-337oo; Ham lugng hydrocacbon thay dii tir 0,54 - 2,78pg/l, trong do viing ven bien khu vyc cang ca Phan Thilt (dilm 4bis) ham lugng hydrocacbon 0,3mg/lit, chung to kha nang bi nhiem dau a viing ven ba khu vyc nay (bang 1)

2 Thanh phan va so luong ciia quan the vi sinh vat ty nhien trong moi trirong ven bien Binh Thuan

2.1 Vai tro cua mpt so nhom vi sinh vat chinh trong nude bien

- Nhom vi khuan hieu khi va len men la cac vi khuan di duong, co kha nang phat trien tren

nguon ca chat san co nhu hydrocarbon, lipid, protein a dieu kifn co oxy hay it oxy

- Nhom vi khuan chuyen hoa cac hgp chat nito bao gom vi khuan nitrite boa va nifrate hoa

va vi khuan khii nitrate Trong do, nhom nitrite hoa se oxy hoa ammonium thanh nitrit dl nhom nitrate boa oxy boa tiep thanh nitrat Nhom vi khuan khir nitrate se khir nitrate thanh nita phan tir, khep kin mgt chu trinh chuyen boa cac hgp chat chira nita

- Nhom vi sinh vat sir dung hydrocarbon va tao chat boat hoa be mat la cac vi sinh vat co kha nang tao chat hoat hoa be mat va sir dung cac hydrocarbon cua dau mo lam ca chat cho sy phat trien So lugng ciia nhom vi khuan sir dung hydrocarbon la chi thj cho sy 6 nhiem dau

Bang 1 Cac thong s6 hoa ly nu'O'c bien Binh Thuan

t r i

1

2

3

4

4 bis

5

6

7

8

9

10

Tog d9

N 10°23'18"

E 107°03'36"

N T'6°28'32"

E 107°03'00"

N 10°26'18"

E 107°06'36"

N 1 0 ° 2 5 ' 3 r

E 107°08'21"

N 10°25'31"

E 1 0 7 ° 0 8 ' 2 r

N 10°26'00"

E 107°06'14"

N 10°21'48"

E 107°07'12"

N 10°30'55"

E 107°00'50"

N 10°29'54"

E 107°00'03"

N 10°27'54"

E 107°02'16"

N 10°26'45"

E 107°09'45"

Dia danh

Hon Ram

Phan Thiet

Cang ca P.Thiet Tien Hal, Tien Thanh

MQI Ke Ga

La Gi - Ham Tan

T h o n g s6 chat lirqrng nu'O'c

pH 7.80 7.84 7.43 7.45 7.56 7.36 7.56 7.63 7.83 8.09 8.12

T ( ° C ) 28.7 28.7 28.2

28 27.8

28 28.2 28.3 28.3 28.4 28.4

DO (mg/l) 5.5 4.7 5.11 4.23 4.13 5.5 5.45 5.96 5.86 5.73 5.61

Dp ddn (mS/cm) 34.9 35.3 38.7 34.4 34.2 53.4 53.2 52.8 51.9

50 49.4

Dp mgn (°/oo)

21.4 21.4 27.4 22.3 20.6 33.7

32 34.2 33.2 32.6 31.6

Dp dye (NTU)

9

14

4

6

8

3

4

3

5

6

11

- Nhom vi khuin khir sulfat la nh&ng vi khuan sir dung ca chat lactate hoac acetate de phat triln va CO kha nang tao H2S Do vay, chiing thuong co mat nhieu a nhung nai co 6 nhiem hihi

ca va ham lugng S04^" cao Sy phat trien ciia chimg gay 6 nhiem va dgc cho dgng thyc v^t frong

he sinh thai Tuy nhien, mgt s6 vi khuan kbii sulfate lai co kha nang su dyng hydrocarbon thom,

CO thi ling dung trong xir ly 6 nhiem dau

Cac nhom vi sinh vat nay dong vai tro rat quan trgng trong chu trinh chuyen hoa v^t chat cung nhu frong he sinh thai bien

Ngoai ra, frong moi truang nuac va fram tich bien luon co mat cua mgt so vi sinh vat gay

benh Nhom vi khuin gay benh Vibrio la loai vi sinh vat gay benh thuong gap a nhiing moi

truang nuac bj 6 nhiem Chiing la nhiing vi khuan gram am hinh cong, ua man, bien dg nhift phat tnin tir 15-40°C, pH la 5-9.6

2.2 Thanh phdn vd so lupng cua mpt so nhdm vi sinh vat tu nhien trong mdi trudng ven bien

Binh Thuan

Ket qua xac djnh so lugng ciia mgt so nhom vi sinh vat trong moi truang nuac va frim tich ven bien cac diem nghien curu cho thay: khu he vi sinh vat khu vyc ven bien Binh Thuan rat da dang va phong phii, bao gom vi khuan hieu khi, len men, chuyen boa cac hgp chat chua nito, sir

dung hydrocarbon, vi khuan khir sulfate va vi khuan gay benh Vibrio (bang 2)

So lugng vi khuan hieu khi (HK) xuat hien a cac mau nuac tai cac dilm tir lO'-lO* CFU/ml; frong khi do a cac mau bim, so lugng nhom vi khuin nay d^t tai 10* CFU/g Chi co tai diem 4 (ven bien thi xa Phan Thilt), mau nuac la 10* CFU/ml va mlu trim tich la 10^ CFU/g So lugng vi khuan hieu khi a diem 4 thap co the co lien quan den ham lugng oxy frong nuoc bien khu vyc nay thap hon so vai cac diem khac

Vi khuan len men (LM) phan bo a cac mau nuac tai cac dilm dat tir 5.10^-5.10^ CFU/ml, a

cac mau biin so lugng nhom vi khuin nay dao dgng trong khoang tir 10^-10* CFU/g Tai diem 4,

so lugng nhom vi khuan nay cung it hon tai cac dilm khac, mau nuac la lO"* CFU/ml va miu biin la 10^ CFU/g

Nhom vi khuan nitrite boa va nitrate boa trong moi truang nuac bien Binh Thuan thap, chi tir <10'-10' CFU/ml, trir khu vyc mui Ke Ga s6 lugng vi khuin nitrite boa dat 10^ CFU/ml So lugng vi khuan nhom nay frong miu trim tich cung chi tir lO'-lO^ CFU/g, co dilm <10'CFU/g Dieu nay cho thiy, qua trinh phan giai cac hgp chat nita viing ven biln Binh Thuan thap Nhom

vi khuin khiir nitrate a cac miu nuac dat tir 10^-5.10" CFU/ml; con a cac miu biin vi khuin khir

nifrate dat tir lO^-lO" CFU/g

So lugng vi khuan sir dyng hydrocarbon (SDHC) xuat hi^n kha cao ca trong mlu nude va mau trim tich dao dgng tir lO^-lO' CFU/ml, chi trir khu vyc La Gi - Ham Tan co s6 lugng thap ban (5.10^ CFU/ml) Nhu vay, khu vyc nay da co bilu hi^n 6 nhilm diu

Ben canh nhom vi khuin hiru ich, nhom vi khuin khir sulfate (KSF) xuit hifn vai sy bien dgng so lugng dang chu y, mau nuac tir 5.10'-10^ CFU/ml, tham chi khu vyc cang ca Phan Thiet dat 10" CFU/ml; trong khi do miu biin so lugng vi khuan nhom nay cao ban 10-100 lin (10^-10^

CFU/g) Theo mgt so tai lifuda cong bo, so lugng vi khuin khu sulfate a frong cac mau nuac tir

10^-10^ CFU/ml va frong miu frim tich tir lO^-lO* CFU/g fra len la diu hifu cua sy 6 nhilm nguon nuac Co thi kit luan viing ven biln Binh Thuan da xuat hifn dau hifu 6 nhilm

_ Ngoai ra, so lugng nhom vi khuin gay benh Vibrio dao dgng nho, tir lO^-lO" CFU/ml; frong

mau tram tich so lugng cung tuong ty, rieng tai dilm Hon Rom-MQi Ne s6 lugng vi khuin gay benh dat 10^ CFU/g Dieu nay cho thiy nuac a khu vyc nay da bi 6 nhilm mgt phin do sinh hoat ciia con nguai Co thi la do tac dgng cua hoat dgng du Ijch

Tieu ban: CONG NGHE SINH HOC B I ^ N VA MOI TRLTONG 559

Qua ket qua phan tich nhan thay, so lugng vi sinh vat a do sau khac nhau thi cung khac nhau, trong do vi sinh vat a mau biin luon cao ban mau nuac tir 10-100 lan Nhom vi khuan hiru ich nhu vi khuan hieu khi, vi khuan len men va vi khuan sii dung hydrocarbon co mat a trong ca mau nuac va mau tram tich vai so lugng Ion Dieu nay chirng to chat hiru ca dugc phan giai manh, cho thay tiem nang ty lam sach ciia moi truang bien khu vyc nay rat tot

So sanh so lugng cac nhom vi sinh vat 6f day vai bien Cat Ba (Hai Phong) cho thay so lugng cac chiing vi sinh vat chuyen hoa cac hgp chat nito a Binh Thuan rat thap, trong khi nhom

VI sinh vat sir dung hydrocarbon lai cao han a Cat Ba [9] Ket qua nay co the dugc giai thich la

do bien Binh Thuan each day 2 nam chju anh huang cua sy co fran dau, do do da kich thich nhirng vi sinh vat sir dung dau phat trien

Bang 2 So lu'qrng mgt s5 n h o m vl sinh vat trong cac m l u nu>6c va tr§m tich tai bien

Binh Thuan STT

1

2

3

4

5

6

7

8

9

10

4bis

Mau

B T - W 1

B T - S 1

B T - W 2

BT-S2

B T - W 3

BT-S3

B T - W 4

BT-S4

B T - W 5

B T - S 5

B T - W 6

BT-S6

B T - W 7

B T - S 7

B T - W 8

B T - S 8

B T - W 9

B T - S 9

B T - W 1 0

BT-S10

NB cang PT

Cac n h o m vi sinh v$t

HK 10®

10®

10®

10®

10' 10' 10' 10' 10®

10®

10' 10®

10®

10®

10®

10®

5.10' 10®

10®

10®

10®

LM 10®

10' 5.10' 10®

10^

10®

10*

10^

10' 10®

10®

1 0 '

1 0 ' 10®

10®

10' 5.10®

10®

10=

10®

10®

NH4

<10' 10^

<10^

10^

<io'

<io'

<10^

10=

10' 10'

<10' 10=

10' 10' 10=

10=

<io'

10' 10' 10=

10'

N03 10^

10^

10*

10*

10*

10®

10*

10*

10*

10*

5.10*

10®

5.10*

10®

10*

10®

5.10*

10®

5.10®

10*

10*

N02

<io'

<io'

<io'

10'

<io'

<io'

<io'

10'

<10'

<10'

<io'

10'

<10'

<io'

<io'

10'

<10'

<io'

<io'

<10' 10'

SDHC 10®

10*

5.10®

10®

10®

10®

10®

10®

10®

10*

5.10®

10*

10*

10®

10*

10®

10®

10®

5.10=

10®

10®

KSF 10=

10®

10®

10*

10®

10*

10®

10*

10®

10*

5.10' 10=

10=

10=

10*

10®

5.10' 10=

10=

10®

10*

Vibrio

1,1.10* 10® 1,3.10® 10* 1,1.10® 3,5.10® 10® 10* 1,9.10® 3.10® 5.10® 0,8.10® 1,2.10® 10* 10* 3.10® 4,8.10® 10* 1,2.10® 10* 2,1.10® Ghi chu: W: mau nuac (CFU/ml) S: mau tram tich (CFU/g)

3 Phan loai cac chiing vi sinh vat dien hinh phan lap tir viing bien Binh Thuan

Sau khi phan tich so lugng va thanh phan cac nhom vi sinh vat tai vimg bien Binh Thuan, chiin" toi da phan lap dugc mgt so chiing vi khuan tren cac moi truang chgn lgc Tien hanh quan

sat khuin lac va xac djnh Gram cac chiing da phan lap dugc, chimg toi lya chgn mgt so chiing vi

560 Tuyen t?p Hgi nghj KHOA HOC TOAN QUOC V£ SINH HQC BlgN vA PHAT TRifeN B £ N VU'NG

khuin diln hinh dl phan loai nhanh den loai bing cac kit chuan sinh hoa API ket hgp vai khoa phan loai vi khuin ciia Bergey Kit qua dugc trinh bay fren bang 3

Bang 3 K§t qua phan loai mot s6 chung vi k h u i n dien hinh phan lap tin bien Binh Thuan

TT

1

2

3

4

5

6

7

8

9

10

Ky hi?u

chung

VKS 1.3.1

VKS 1.3.3

P T W 5 2

P T S 6 1

PT S 6.2

P T S 8 1

BT-VK9

VKW9.2

VKS 9.3.1

BT-VK10

Hinh thai khuan i^c

Vang cam, tron loi bong uot, mep gpn,

d=2.0mm

TrSng nga, hoi loi, bong ifcrt, mep gpn,

d=5.5mm

T r i n g trong, trong bong, nhay, dinh,

d= 0,8cm Vang t u ' d , lam vang moi tru'd'ng, be mgt det, phang deu, bong uot, mep khong gpn, khuan lgc to, d=0,8cm Vang dye, be mgt loi, bong u61, mep khong gpn, nhay, d=0,8cm Xanh, giu'a xanh dgm tgo chop nhpn, vanh nhgt han, be mgt bong ucrt, mep

gpn, d= 0.5cm Trlng nga, mep rang cua, p h I n g , khuan lgc to, d=4.5mm

Tr§ng sOa, hai loi, be mgt kho bong, vong dong tam, d= 4.0mm

Trang nga, tron loi, vong dong tam, mep vi4n, d= 2.5mm Tring, bong uat, loi, gpn, nho cao,

d=2mm

Gram

-+

-Phipo-ng phap phan log!

API 20 NE

API 20 NE

API Rapid E

API Rapid E

API Rapid E

API Rapid E

API Rapid E

API 50 CHL

API 20 NE

API Rapid E

Ten loai (ID)

Brevundimonas vesiculasis (98%)

Brevundimonas diminuta {"[00%)

Serratia plymutica

(100%)

Vibrio alginolyticus

(99%)

Vibrio cholerae

(98%)

Vibrio parahaemolyticus

(98.8%)

Enterobacter gergoviae (98%)

Lactobacillus sp

(100%)

Chryseomonas sp

(100%)

Aclnetobacter sp

(97%)

Ket qua bang 3 cho thay, trong so 10 chimg vi khuan dai dien phan lap dugc tir viing bien nay chii yeu la vi khuan gram am chi co mgt chiing vi khuan gram duang la chimg VKW 9.2 Hinh thai khuan lac cua chung cung rit da dang: 3 chiing VKS 1.1.3, P T S 6.1 va PT S6.2 co mau sac khuan lac vang, chiing PT S 8.1 co mau xanh con hiu hit cac chiing diu co mau fring Cac chiing vi khuan phan lap tai vimg bien nay thuong co hinh fron

Trong so cac chiing vi khuan da phan loai dugc thi co 4 chiing thugc cac loai:

Brevundimonas vesiculasis VKS 1.3.1, Brevundimonas diminuta VKS 1.3.3, Chryseomonas sp VKS 9.3.1, Acinetobacter sp BT-VKIO, theo nhilu cong bo tren the giai thi cac chi vi khuan

nay deu co kha nang phan huy dau Nhu vay, khu vyc nay rat co tiem nang iimg dung nhom vi khuan huu ich ngi tai nay vao viec xir ly 6 nhiem dau

Tieu ban: CONG NGHE SINH HOC B I ^ N VA MOI T R l / O N G 561

Ngoai ra thi chimg toi con phan loai dugc 3 chiing vi khuan thugc chi Vibrio: V parahaemolyticus PT S 8.1, V alginolyticus PT S 6.1, V cholerae PT S 6.2, day cung la cac loai Vibrio thuang co mat trong nuac bien ven ba 6 Viet Nam Dac biet, a day chiing toi phan lap dugc chiing V cholerae PT S 6.2 la loai vi khuan gay benh ta cho nguai Do do can canh bao de

phong cho nguai dan ciing nhu khach du lich luu y vi khu vyc nay thuang dien ra cac boat dgng nhu khai thac thuy san va du lich

4 Danh gia kha nang phan hiiy dau tho mo Bach Ho ciia quan the vi sinh vat ty nhien trong nuac bien Binh Thuan

4.LThu nghiem ddnh gid khd ndng phdn huy ddu tho mo Bach Ho trong moi trudng mo phong tu nhien khong hoan todn

Ciing nhu cac phuang phap tieu chuan a mire do phong thi nghifm khac, thir nghiem

BODIS Marine co the khong hoan toan giong dieu kien ty nhien, nhung nhirng chat thir nghiem dat tieu chuan quy dinh trong thir nghifm nay se dugc xem la co kha nang phan hiiy sinh hgc trong moi truang bien (theo OECD guideline, 1992) [3]

Nuac bien diing de thir nghiem dugc lay tir viing bien Binh Thuan, luu giir trong dieu kien duong khi a nhiet do phong thi nghiem Truac khi sir dung, loai bo cac can tho bang each de lang va gan bo Ngoai cac mau thir nghifm, Benzoate Natri (C6H5COONa) dugc sir dung lam chat so sanh, vai muc dich kiem tra boat dgng ciia vi sinh vat trong nuac bien

Xac djnh nhu cau oxy sinh hoa (BOD) ciia cac binh thir nghifm dugc do a 4 thai diem 0, 7,

14, 21, 28 ngay ke tir luc bat dau thir nghifm

Ngoai ra con xac dinh nhu cau oxy hoa hgc (COD) ciia chat thir

Ket qua tom tat ciia thir nghifm phan hiiy sinh hgc tren doi tugng dau tho Bach Ho dugc trinh bay tren hinh 1

100

Nhanh

14 21 Tlioi giau (ngay)

Hinh 1 So sanh kha nang phan huy sinh hoc cua d i u tho Bach Ho v a i do! chu-ng

Cac kit qua phan ra sinh hgc ciia mau chuan va cac thong so ciia qua trinh thir nghiem theo phuang phap Bodis Marine deu thoa man cac dieu kien yeu cau cho thir nghifm phan hiiy sinh hoc [3]'

562 Tuyen t^p Hgi nghj KHOA HQC TOAN QU6C Vfe SINH HQC BifeN VA PHAT T R | £ N B^N VCTNG

Theo tieu chuin OECD (1992), mgt chat thir nghiem dugc xem la co kha nang phan ra sinh

hgc de dang trong dilu kifn moi truang bifn khi chat do bj phan ra fren 60% sau 28 ngay thir

nghifm Diu tho mo Bach Ho bj phan ra sau 28 ngay la 49%, nhu vay co the ket luan diu tho

mo Bach H6 dugc xep vao loai khong co kha nang phan buy sinh hgc de dang trong moi fruang

nuac bien ty nhien [3]

4.2 Thir nghiem ddnh gid khd ndng phdn huy dau tho Bach Ho cda quan thi vi sinh v^

trong nude bien Binh Thuan khi bo sung chat dinh dudng

Tien hanh thiet ke thi nghifm danh gia kha nang phan huy dau tho Bach Ho ciia quin the vi

sinh vat trong nuac bien Binh Thuan khi bo sung chat dinh duong:

- Mau doi chung 1 (BT-DCl): 50ml nuac bien da khir triing + 5% diu tho Bach Ho

- Mau doi chirng 2 (BT-DC2): 50ml nuac bien chua khir triing -i- 5% diu tho Bach H6

- Cac mau thi nghifm: 50ml (5g) nuac bien (tram tich bien) theo vi tri nghien ciru + 5% dau

tho Bach Ho + 0,3g/l Photpho + 0,3g/l Nito

- Dau tho Bach Ho, Photpho, Nita dugc khir triing truac khi bo sung, cac mau thii nghifm

dugc nuoi lac lien tuc 120 vong/phut a 30°C (± 1°C) frong 15 ngay

Hinh 2 Kha nang phan huy dSu tho B^ch Ho cua quin the vi sinh v f t trong m l u nu'ac vi

t r i m tich Sau 15 ngay nuoi cay, vi sinh vat phat trien manh a trong ca miu nuac va miu trim tich do

chung CO CO che trao doi chit thi'ch nghi vai moi truong Dung dich trong tit ca cac miu thir

va chuyen mau nau vang, khdi diu dua vao thir nghifm hiu nhu diu bi phan

^ ^ - - _ 7 w ^1^ , m » " i i 5 , iviiwi \aau u u a v a u lllU llgiutplll IiaU tUlU UCU Vl puail

giai ha^ bi phan hoa thanh nhimg gigt nho ban hoac bj nhQ tuang hoa vao moi truang Nhu vay,

tinh chat vat ly va hoa hgc cua diu tho da bj thay doi va no rit co y nghTa trong viec dl dang lam

giam muc do gay 6 nhilm C5 mau doi chimg 1, kh6i diu dua vao hau nhu khong thay doi, vi

nuac bien khii friing da loai bo vi sinh vat co trong miu Con a miu d6i chiing 2, quan sat thay

lugng dau dua vao co bi phan ra nha vi sinh vat sin co, tuy nhifn mire dg phan ra khong manh

Kha nang phan buy dau tho cua quin the vi sinh vat ty nhien frong moi truang nuac va frim tich

bien Binh Thuan sau 15 ngay thir nghifm dugc thi hifn a binh 2 va bang 4

Quan sat bang 4 cho thiy, mau DC 1 ham lugng dau hiu nhu khong thay doi 6 miu DC 2,

^r^io/'^^^^ "^'^ "^""^ ^^ ^™^ ^^^^ ^'"^ '^^^^ 'l"^" *^ ^' ^'"'^ ^^^ ^ "'i'^" ^^ P*^^" ^^^

J8.67/0 lugng dau dua vao Con doi vai cac mau thir nghiem, khi b l sung chit dinh duang thi

ham lugng dau a cac mau deu giam tren 65%, cao han rit nhilu khi khong b6 sung chit dinh

i^ong ly If dau tho Bach Ho bi phan buy bai quin thi vi sinh vat trong nuac biln khi bo sung

Tieu ban: CONG NGHE SINH HQC BI^N VA MOI TRl/Q-NG 563

chat dinh duong dat tir 67 den 7 1 % , con frong miu trim tich giam tir 70 din 75% Miu co ty' If giam nhieu nhat la mau tram tich s6 9 (Lagi) dat 75.26%, mau giam thip nhit la miu nuac bien so

6 (Tien Thanh), dat 67.27% Tir ket qua tren nhan thay, kha nang phan buy dau tho Bach Ho ciia quan the vi sinh vat frong mau fram ti'ch cao han frong mau nuac tai tat ca cac vi fri, tuy nhien kft qua chenh lech khong cao, trung binh 5% tai thai diem ket thiic thir nghifm Kha nang phan buy

dau ciia vi sinh vat giira cac vi tri nghien ciru khong cho thay co sy khac bift ro ret o ca mau frim

tich va mau nuac Nhu vay, ket qua danh gia kha nang phan buy dau tho Bach Ho cua quin thi vi sinh vat ty nhien frong moi truong ven bien Binh Thuan rat kha quan Theo Margesin va Scbinner, frong rat nhieu cac thiir nghifm da thyc hifn thi ham lugng hydrocarbon khong thi giam tai 0 a bat

ky thir nghifm nao, ham lugng dau con lai thuang vao khoang 10-30% [11] Co nhilu nguyen nhan gay ra hifn tugng nay, trong do bao gom: sy tich luy cac thanh phin kho bj phan buy, vifc tao ra dgc to hoac c6 nhirng yeu to ngan can cac qua trinh frao doi chat

Bang 4 Kha nang phan huy d i u tho Bach Ho cua q u i n the vl sinh vat trong cac m l u

nu'ac bien va t r i m tich sau 15 ngay thii' nghifm

TT

1

2

3

4

5

6

7

8

9

10

11

12

K y hipu

m a u

BT-BC 1

BT-DC 2

BT-S-1.2

BT-S-2.2

BT-S-3.3

BT-S-4.2

BT-S-5.3

BT-S-6.2

BT-S-7.3

BT-S-8.2

BT-S-9.3

BT-S-10.2

H a m Iu'p'ng diu ban dau (mg/l)

40876

40876

40876

40876

40876

40876

40876

40876

40876

40876

40876

40876

H a m Iu'p'ng diu con Igi (mg/l)

40856

25069

10946

10505

10533

11821

10881

12262

10975

11473

10112

12258

Ty Ip diu phan hiiy (%)

0.05

38.67 73.22 74.30 74.23 71.08 73.38 70.00 73.15 71.93 75.26 70.01

TT Ky hipu

m l u

H a m Iu'p'ng diu ban diu (mg/l)

H a m Iu'p'ng diu con Igi (mg/l)

Ty ip diu phan huy (%)

13

14

15

16

17

18

19

20

21

22

BT-W-1.2 BT-W-2.2 BT-W-3.1 BT-W^.1 BT-W-5.1 BT-W-6.1 BT-W-7.1 BT-W-8.2 BT-W-9.3 BT-W-10.2

40876

40876

40876

40876

40876

40876

40876

40876

40876

40876

12937

12565

12781

12630

11322

13378

11972

12344

12262

12246

68.35 69.26 68.73 69.10 72.30 67.27 70.71 69.80 70.00 70.04

Cac ket qua thir nghiem kha nang phan huy dau tho cua vi sinh vat a Binh Thuan cung hoan toan hgp ly, khi cac nghien cuu truac day cua chung toi cung nhu mgt so nha khoa hgc khac da chung minh dugc rang, khi bo sung mgt lugng dinh duong nhat djnh co the tang cuong kha nang

phan buy diu a cac dja diem 6 nhiem bang vi sinh vat ngi tai [4]

Theo cong bo mai day ciia Lai Thuy Hien va cgng sy da danh gia kha nang phan buy dau ciia quin thi vi sinh vat tai Quang Nam va Vung Tau Ket qua cho thay, vi sinh vat frong cac

mau cat biln a day da sir dung dugc 46.4% dau diezel va khi bo sung chat mang bentonit da kich

thich cac vi sinh vat ngi tai su dung tai 81.2% dau tong so [8] Nhu vay, ket qua nghien cuu kha nantJ phan buy dau ciia quan the vi sinh vat tai Binh Thuan them mgt lan nira khang djnh vifc irno dung vi sinh vat trong xir ly 6 nhiem dau la hoan toan kha thi neu bo sung chat dinh duong hgp ly de kich thich sy phan buy dau ciia hf vi sinh vat ngi tai

564 Tuyen tap HQi nghj KHOA HQC TOAN QU6C V£ SINH HQC B | £ N V A P H A T T R | £ N BgN VCfNG

IV KET LUAN

1 Kit qua phan tich quin thi vi sinh vat trong cac mau nuac va fram ti'ch tai khu vyc bien Binh Thuan cho thay so lugng cac nhom vi sinh vat a cac mau tram tich cao ban so vai cac mlu nuac be mat tir 10-100 lan

2 Thanh phan cac nhom vi sinh vat a day rat da dang, vai so lugng: Vi khuan hieu khi lO'-10^ (CFU/ml); len men lO'-lO' (CFU/ml); sir dung hydrocacbon 5.lO'-10^-lO'-10^ (CFU/ml), nhom vi khuin chuyin hoa nito 10'-10^ (CFU/ml), vi khuin khir sunphat5.10'-10'' (CFU/ml) va vi khuin

gay bfnh Vibrio 10^-10^ (CFU/ml)

3 Dya vao dac diem hinh thai va sir dung kit chuan sinh boa (API 50 CHL, API 20 NE, API Rapid 20 E) da dinh ten dugc 10 chiing vi khuan dai difn, trong do co 6 chung hiru ich va 4 chung vi khuan gay bfnh:

- Chiing VKS 1.3.1 thugc loai Brevundimonas vesiculasis

- Chung WKS ].3.3 thuoc loai Brevundimonas diminuta

- Chiing PT W 5.2 thugc loai Serratia plymutica

- Chiing PT S 6.1 thugc loai Vibrio alginolyticus

- Chiing PT S 6.2 thugc loai Vibrio cholerae

- Chiing PT S 8.) thugc loai Vibrio parahaemolyticus

- Chiing BT-VK9 thugc loai Enterobacter gergoviae

- Chiing VKW 9.2 thugc loai Lactobacillus cuvantus

- Chiing VKS 9.3.1 thugc loai Chryseomonas sp

- Chiing BT-VKIO thugc loai Acinetobacter sp

4 Sau 28 ngay thir nghifm, diu tho mo Bach H6 bj phan buy la 49%, nhu vay dau tho mo Bach Ho dugc xep vao loai khong co kha nang phan buy sinh hgc dl dang frong moi truang nuac bien ty nhien

5 Khi dugc b l sung chit dinh duong, quin the vi sinh vat trong nuac biln va frim tich Binh Thuan co kha nang phan huy diu tho Bach H6 vai ty If tir 67.27-75.26%

V TAI LIEU THAM KHAO

1 Aislabie J, Saul DJ, Foght JM (2006) Bioremediation of hydrocarbon containminated polar

soil Extremophiles 10(3): 171-179

2 Atlas RM (1995) Bioremediation of pefroleum pollutants International Biodeteriration and Biodegradation: 3\1-321

3 Bodis Manne method - Modified seawater variant of ISO TC/147, SC5/WG4 N141: "BOD

Test for Insolube Substances", 1995

4 Bin Thj Kim Anh, Dang Dinh Kim, Akihiko Maruyama (2007) LTng dung ky thuat phan tich phan tir de xac djnh thanh phin va so lugng vi sinh vat trong thi nghiem xir ly 6 nhilm

dau bang phuang phap sinh hgc Tap chi Cong nghi Sinh hpc 5(4): 505-512

5 Dinh Dung (2008) Lo ngai 6 nhiem moi truang a Mui Ne Thai bdo kinh ti Sai Gbn (7/1/200S-\i'\u\\ binhthuantodav.com)

6 Haider AK Uchiyama K, Shioya S (1996) Isolation and Characterization of

Poly-D(-)-3-hydroxylalkanoat (PAH) Degrading Bactena Annual Reports of International Center for Bioiechnolog); Osaka University, Japan 19: 212-222

7 Head IM, Jones DM, Rolling WFM (2006) Manne microorganisms make a meal of oil

Nature reviews Microbiology 4(3): 173-182