Tap chi KHOA HQC BHSP TPHCIVI So 36 nam 2012
ANH H U O N G CIJA MAT Dp XUAT PHAT DEN TANG TRUdNG CUA VI TAO SKELETONEMA COSTATUM (GREWLLE) CLEVE
TRONG MOI T R U P N G N U P C BIEN NHAN TAO AQUIL*
L V THj THUY DUYEN', VO H O N G TRUNG". Le THI TRUNG"' T6M TAT
17 tdo Id thirc vdt phii du cd kich thudc hien vi. cd cdu tao dan bdo .sdng trdi noi trong nirdc. trong dd tdo silic Id ngdnh ldn nhdt cd ve sd loai vd .sinh vdt lirtmg Mdt do niidi cdy la mot trong nhirng yeu to cd lien quan mat thiet den sinh khdi vd thdi gian tdo dat cue dai Skeletonema costatum (Gtev.) Cleve tdng tnrdng tdt nhdt tren mdi trudng .4guil* d mat do nudi cdy 30.000 ti' hdo/ml. dnh .sang 3.000 lux ± 500. nhiet do 25"C ± 2.
cho chudi te bdo ddi. sdc the dam mdu. cd dudng cong tdng trudng dien hinh.
Id-khoa: Skeletonema. Sac the. moi truang Aquil*.
ABSTRACT
The morphological changes of cells accompany with Ihe growth cycle of microalgae Skeletonema costatum fCreville) Cleve in Ihe artificial seawaler medium Aquil*
Microalgae as phytoplankton are unicellular algae in microscopic size floating in the water, in which diatom is the biggest phylum in term of species numbers and biomass.
Initial cell density is one of the factors closely related to algal biomass and time when algae reach the maximum biomass. Skeletonema costatum ("Greville) Cleve grows the best in the Aqud* medium with initial cell density 30.000 cells/ml. light intensity S.OOOlia ± 500, temperature 25''C ± 2; the long-chained cells, the darker chromatophores. and the typical growth curve.
Keywords: Skeletonema, chromatophores, Aquil* medium.
1. Mo* dau
Vi tao la thirc vjt phii du co kich thuoc hien vi, co ciu tjo dan bao s6ng troi n6i trong nuoc, co kha n5ng quang tu duong, rit da d?ng ve hinh d?ng, mau sic, kich thuoc va moi truang phan bd.
Moi truong NBNT chira cSc ion quan trpng va cac tac nhan tap chelat de duy tri day dii ham lupng cac nguyen to vi lupng trpng dung dich va cac nhan t6 tang trucmg hiru ca. Theo Droop (1961, 1962), su hinh thanh chelat ciia cac nguyen td vi lupng, dem pH va sy can bang hieu the oxy hoa khir, mpt s6 hay tit ca cac dac tinh hoa 11 nay ciia mpt moi trucmg co thS quyet dinh dSn sg- tSng truang ciia loai thuc vat phii du hon la ti le ciia cac ion chinh (Fogg and Thake, 1987).
• HVCH, Trudng Dgi hpc Su pham TPHCM _" HVCH, Tru&ng Dai hgc Su ph?m TPHCM
"' TS, Truing D?i hgc Su phjm TPHCM 56
Tap chi KHOA HOC BHSP TPHCM Ly Thi Thuy Duyen va Igk
Mat dp te bao trong djch nuoi co lien quan den kha nang cung cap nguon song cua moi truang, tir do anh huang lan den su tang truang cua vi tao.
Viec xac dinh mat dp xuat phat thich hap co vai tro quan trpng trong nghien cim sinh li vi tao, gop phan tao co sij de ra cac phuang phap giiip chu dpng dieu khien toe dp tang truang cua tao.
2. V^t lieu, phu'o'ng phap 2.1. Vat lieu
Vi tao Skeletonema costatum (GrcxiUe) Cleve dupc thu tir nuac bien ven bo Dong Hoa, xa Long Hoa, huyen Can Gio, TP Ho Chi Minh.
2.2. Phuang phdp 2.2.1. Chuan bi mdi tnrdng
Moi trucmg Aquil*, pH 7 ± 0,5 (Sunda W. G., et. al., 2005), giu a nhiet dp 25°C±2 tai da 1 thang.
DiSu kien nuoi: chu ki sang t6i 12:12, dp am khoang 50%, nhiet dp: 25°C ± 2, cuang dp sang: 3000 lux ± 500.
2.2 2. Quan sdt hinh thdi te bdo
Skeletonema costatum dupc quan sat hinh thai m6i ngay va chup hinh dual kinh hien vi quang hpc.
2 2 3. Xdc dmh mat do te bao
Mat dp te bao dupc dSm bang khung d^m h6ng ciu va tinh theo cong thirc:
D = - X 10'' tS bao/ml
D : mat dp tg bao ; n : tong s6 xk bao trong cac lin dem ; i: so lin dem (Andersen and Throndsen, 2004).
2.2.4. Xdc dinh dudng cong tdng trudng
Duang cong tang truang dupc xay dimg dua tren mat dp te bao xac dinh moi ngay.
2.2.5. Xdc dinh he sdpha loang ^ DS CO dupc mat dp xuit phat cr cac nghiem thirc va cac binh nuoi la nhu nhau, he
so pha loang dupc tinh:
.V
He so pha loang = —jrj.
n: s6 luat d6m miu g5c; N: t6ng so if bao d^m duac trong n lupt; V: the tich m6i viing dSm (ml); Di: mat dp xuit phat cin co (te bao/ml).
. 2.2.6. Xdc dinh mat do nuoi cdy thich hap
Cac mat do duac khao sat: 15.000 te bao/ml; 30.000 ti bao/ml; 45.000 d bao/ml;
va dupc xac'djnh dua tren dudng cang tang trudng, toe dp tang trudng va hinh thai te bao.
57
Tap chi KHOA HOC BHSP TPHCM Sd 36 nam 2012
i. Ket qua, thao luan
3.1. Tdng irumig ciia Skeletonema costatum Irong mol tnrdng Aquil*
3.1.1. Hinh thdi li bdo
Ciic t6 bao X costatum cd chuoi dai. kich thudc khii to, s i c the chi6m phin ldn kich thudc tc- bao tir ngay thir 1 den ngay thir 5. Tir ngay 3 ddn ngay 5 cd nhieu te bao phan ddi. 0 ngay 5. ciic te bao giam kich thudc dang ke. Den ngay 6, cd hien tupng Ihoat s i c to, te bao nhat mau (anh 3.1).
Anh 3.1. Te bdo Skeletonema costatum trong mdi tnrdng Aquil* dr ttgirv 1 den ngdy 6 3. L2. Mat do te bdo - Dudng cong tdng tnrdng - Tdc do tang tnrdng
Thdi gian tang trucmg ciia vi tao trong mdi truimg Aquil* keo dai 7 nga\. pha 1(
cd dinh tang trudng d ngay 5 vdi 131. lO"" te bao/ml (hinh 3.1).
110 00
1(11100 So 00 so 00 40 00 :ooo 0 00
-.^qllll'
Nl N2 m N4 N5 N6 N"
Tlicri o i a n ( n g a v )
Hinh 3.1. Duang cong tdng truang Skeletonema costatum trong mdi trudng Aquil*
Tap chi KHOA HOC DHSP TPHCM Ly Thi Thiiy Duyen vd Igk
3.2. Khao sal sir sinh Irirdng a cdc mat do .xuat phdi khdc nhau 3 2.1. Hinh thdi te bdo
Tir ngay thii 3 d6n ngay thir 6:
6 inat do xuat phat 15.000 tb/ml: te bao kk chudi khdng dai. Vao ngay 2 va ngay 3 sac the to. dam. Ngay 4. sic the- phan manh. ddn sal v6 vach IS bao. Viio cic ngay tiep sau, te bao \ i tao budc vao giai doan suy ySu vi chit (anh 3.2).
Anh 3.2. Hinh thai te bdo Skeletonema costatum d mat dg xudt phdt 15.000 tb/ml tir ngdy 2 den ngdy 7
Mat do xuat phat 30.000 tb/ml: cac te bao ket chuoi dai. 6 ngay 2 va ngay 3, ti bao to, khoang each giua 2 te bao ngan, sac the chiem iron the tich te bao. Den ngay 4.
te bao to nhimg sac the phan manh nam sat vach te bao. Sang ngay 5, te bao tron. dam mau, sac the phan tan trong te bao, so te bao trong chuoi tang nhung kich thuoc te bao giam dang ke. DiSu nay cho thay vi tao da trai qua giai doan sinh san bang phan doi manh me (anh 3.3, N5). Sac the nhat hon vao ngay 6. 0 ngay 7, nhieu te bao khoi phuc lai kich thuac nhimg co hien tucmg thoat sac to (anh 3.3, N6, N7).
Mat do xu5t phat 45.000 tb/ml: li bao ket chudi dai ngay tu ngay 2, t^ bao to, tron, khoang each giiJa 2 ti bao gan nhau, sac to phan bo kha deu trong te bao. Den ngay 4, kich thuac ti bao giam, s6 te bao trong chudi nhi^u, khoang each giGa 2 ti bao xa nhau. Tu ngay 5, t^ bao co chilu huang suy vong (anh 3.4, N5, N6, N7).
3.2.2. Mat do te bdo - Dirong cong tdng tnrcmg - Toe do tdng tnrcmg
d mat dp xuit phat cang cao, thofi gian pha log cua quin the djch nuoi cang ngan, vi tao nhanh dat d^n mat dp cao nhit (bang 3.1). Trong do, mat dp ti bao cue dai d diSu 59
Tap chi KHOA HOC BHSP TPHCM So 36 ndm 2012
kien mat dd xuit phat 30.000 te bao/ml la 112. 10* te bao/ml va cao hon hai dieu kien xuit phat cdn lai (baitg 3 1).
Mat dp xuat phat 30.000 te bao/inl thich hop cho su tang trudng ciia tao.
N6 N7 i?;^.
Anh 3.3. Hinh thdi te bdo Skeletonema costatum a mat dg xudl phdi 30 000 tb/ml tir ngdy 2 den ngdy 7
Anh 3.4. Hinh thdi te bdo Skeletonema costatum & mot dg xuat phdt 45 000 tb/ml ngdy 2 den ngdy 7
Tgp chi KHOA HOC DHSP TPHCM Ly Thi Thiiy Duyen vet tgk
Bang 3.1 Mat do te bdo ciia Skeletonema costatum a cdc mgt do xudt phdt khdc nhau
Thoi gian (ngay)
1 2 3 4 5 6 7 8
Mat do tc bao (tb/ml) 15.000
2.6 ± 0.02"
2,94±0.0 9'' 6.56±0.16' 38,5±0.09'' 65,7±0.13'-' 103,4±0,16''
93,7±0,7'^
66,4±0,18'
30.000 5.85±0,19"
7.32± 0,07"
23.6±0,06'' 85,2±0,5' 112±0,14' 92,5±0,07' 75,9*0,07"
42,9±0,14=
45.000 10,3*0,12"
31,5*0,05' 77,9±0,11' 93,4*0,09"
82,3*0,18' 47,2*0,13"'=
50,2*0,13'"
29,9*0,08'' Cdc SO trung binh trong cot vai cdc mdu tir khdc nhau khdc biet cdy nghia a mirep=0.05
Dan vi tinh x W'tb/ml.
Su thay doi mat dp xuat phat co anh hudng ldn den su tang trudng cua vi tao. Do do, viec chpn mat dp xuat phat thich hpp rat can thiet cho nghien cuu sinh h. O Viet Nam, tren loai Skeletonema costatum, nuoi trong binh tam giac vdi the tich dich nuoi la 50ml, Nguyen Tan Dai da chpn mat dp xuat phat la 15.000 te bao/ml. Khi cay chuyen cung mat do tren vao 125ml djch nudi tao tang trudng kha tot nhung pha cam ung dai han va mat do cue dai thap hem d dieu kien xuat phat la 30.000 te bao/ml. CJ mat dp xuat phat 45.000 te bao/ml, thdi gian tang trudng cua quan the nit ngan hon, vi tao nhanh chdng suy yeu. Co le, do so lugng te bao nhieu ngay tu dau lam tang kha nang canh tranh ngudn dinh duang, ngudn sang ddng thdi cung sdm giai phdng nhiSu chat thai ra mdi trudng.
4. Ket luan
Skeletonema costatum (Grev.) Cleve tang trudng tdt trong mdi trudng nude bien nhan tao Aquil*, vdi tdc dp tang trudng cao. Mat do nudi cay thich hap la 30.000 t^
bao/ml.
Tap chi KHOA HQC DHSP TPHCM Sd 36 nam 2012
TAI Ll^:il THAM KHAO
Andersen P.. Throndsen J. (2004). E.sfimating cell numbers. In. llallegraef G. M..
Anderson D. M.. Ccmbella A. I), (eds). Manual on harmful marine microalgae, Paris: UNFSCO Publishing, pp. 99-130.
Droop (1962). Algal physiology and biochemistry. Hotanical monorgraph., Voi (10).
Fogg G. E.. Thakc B. (1987). .-ilgac cultures and phylopkmtonk ecology. The University of Wisconsin Press.. Vol 3, pp. 12-42.
Sunda W. G.. Price N. M.. Morel F. M. M. (2005), Trace metal ion buffers and their use Ul culture studies. In: Andersen R, A. (ed.). Algal culluring techniques, Amsterdam: Elsevier Academic Press, pp. 35-63.
(Ng^y Tda so^n nh$n dirge bii 26-12-2011. ngdy chip nh$n dSng 24-4-2012)