全 文 ：EfectsofL -carnitine on Population Growth of
NannochloropsisoculataandTetrahymenasp.
GEChen-xia, DONGXiao-qing, HOUChuang, ZHANGDong-ming＊
ColegeofAnimalScienceandTechnology, JilinAgriculturalUniversity, Changchun130118
Abstract　[Objective] TheaimwastostudytheefectsofL-carnitineonpopulationgrowthofNannochloropsisoculataandTetrahymenasp..
[ Method] WhentheconcentrationofL-carnitinewas0, 50, 100and1 000mg/L, populationdensitiesofNannochloropsisoculataandTetrahy-
menaweredeterminedrespectively.[ Result] Addinghigh-doseL-carnitinehadasignificantinhibitionefectonthepopulationgrowthofNanno-
chloropsisoculata(P<0.05).AddingL-carnitinehadasignificantproliferationpromotingefectonthepopulationgrowthofTetrahymena(P<
0.05).[ Conclusion] TheresearchprovidestheoreticalbasisfortheapplicationofL-carnitineasfeedadditiveinaquaculture.
Keywords　L-carnitine;Nannochloropsisoculata;Tetrahymenasp.;Multiplication
Received:August9, 2010　　Accepted:September1, 2010
Supported by NationalNaturalScience Foundation ofChina
(30671621).
＊Correspondingauthor.E-mail:dmzhang@jlau.edu.cn
　　L-carnitineasafeedadditiveiswidelyusedinfeedpro-
cessing, andtheirhavebeenlotsofreportsoftheeffectsof
, L-carnitineonfish[ 1] .Asanewfeedadditive, L-carnitinehas
agreatvalueinfishbreeding.Itcanimprovetherelative
growthrateoffish, increasetheabsoluteweightofthefish
andreducethefeedcoefficient.SufficientquantumofL-carni-
tineinfeedcanreducethefatcontentoffish.Nannochlorop-
sisoculataisakindofmarinesinglecelmicroalgaeandwide-
lyusedinaquaculture, mainlyincultivatinganimaldiets(such
asrotifers)andparentshelfish[ 2] , anditsapplicationinartifi-
cialbreedingofmittencrabalsoreceivedgoodresults[ 3].
Somerelatedstudiesontheeffectsofdifferentconcentrations
ofL-carnitineontheproliferationofNannochloropsisoculata
havebeenreported[ 4].However, itsefectonproliferationof
Tetrahymenahasnotbeenreported.Inthisstudy, theefects
ofL-carnitineatdiferentconcentrationsonproliferationof
NannochloropsisoculataandTetrahymenaweremeasuredin
ordertoprovidetheoreticalbasisfortheresearchontheappli-
cationofL-carnitineasafeedadditiveinaquaculture.
MaterialsandMethods
Materials
NannochloropsisoculatawasfromAquacultureLaborato-
ryofAnimalScience, JilinAgriculturalUniversity.Seawater
wasconfectedwiththeman-madeseawater(producedby
Haihuatianlingman-made sea waterFactoryinWeifang,
Shandong)andtapwater(whichhadbeenaeratedfor24h),
andthesalinitywas26.9×10-6.L-carnitinewasproducedby
SigmaCompanyinUSA.
Methods
Cultureconditions　Theculturemediumformulawasasfol-
lows:50 mg/Lurea, 1 000 mg/Lammonium sulfate, 150
mg/Lsuperphosphate, 50 mg/LEDTAand10 Lseawater.
Thefluorescentwasusedasthelightsourceinindoorcultiva-
tion, andthelightintensitywas3 500 lx, andtheilumination
timewas24 h.Temperaturewascontroledat22 ± 3 ℃.
Seawatersalinityforculturewas26.9 ×10-6 , anditspHwas
nearneutral.
Experimentaldesign　TheL-carnitineconcentrationwasset
to0, 50, 100, 1 000 mg/Lrespectively, withthreerepetitions
foreachgradient.Thecontrol(0 mg/LofL-carnitine)wasin-
oculatedwiththesameportionofmicroalgaeseeds.Before
inoculation, 2 000mltriangularflasksusedinexperimentwere
sterilizedwithpotassiumpermanganate.Thenthemicroalgae
cultivationwhichhadbeenculturedfor1dwasinoculatedinto
theflaskwiththeculturevolumeof2 000ml.Theflaskswere
sealedwithsterilesealingmembraneandmarked.Aeratione-
quipmentwasplacedintoeachflasktomakethesolutionsha-
kingwelduringculture.
Thedeterminationoftheindexes　① Thedetermination
proceduresofNannochloropsisoculatadensitywereasfol-
lows:thesamplewascolectedat8:30 ameveryday, and1
mlofculturesolutionatdiferentdepthswascolectedfromev-
erybotle.Afterthesolutionwasputasidefor3 -5 min, the
algalcelssinktothebottomoftheflask, andthenitwas
countedwithbloodcelcounter.② ThemeasurementofTet-
rahymenadensity:itwasdeterminedbycountingwitha0.1
mlcountingframe.
Dataprocessing
Relativegrowthconstantwas:K=(lgO.D1 -lgO.D0)/T[ 5];
averagedoublingtime:G/d=0.301/K.Intheformula, O.D1 was
thealgaeconcentrationattheendofculture;O.D0 wastheal-gaeconcentrationatthebeginningofculture;andTwasthe
culturetime(d).
SPSS11.0 softwarewasusedforvarianceanalysison
data, andthecomparisonofsignificantdifferencewascarried
outbytheuseofthemethodproposedbyDuncan[ 6] .
ResultsandAnalysis
TheeffectsofdifferentconcentrationsofL-carnitineon
Nannochloropsisoculataproliferation
Fourconcentrationsof0, 50, and100, 1 000 mg/Lwere
settoinvestigatetheeffectsofL-carnitineonNannochloropsis
oculataproliferation.ItcouldbeconcludedfromTable1 that,
diferentconcentrationsofL-carnitinesignificantlyinhibited
Nannochloropsisoculataproliferation(P<0.05).Duringthe
1
st-5th day, theNannochloropsisoculatadensitiesbetween
fourconcentrationswerenotsignificantlydiferent(P>0.05);
onthe7thday, therewasasignificantdiferenceinNanno-
AgriculturalScience＆Technology, 2010, 11(7):157-159Copyright 2010, InformationInstituteofHAAS.Alrightsreserved. PlantProtection
chloropsisoculatadensitybetween100, 1 000 mg/Land0,
50 mg/L(P<0.05).However, thedifferencebetweenthe
concentrationsof100 mg/Land1 000 mg/Lwasnotsignifi-
cant, whilethediferencebetweentheconcentrationsof0
mg/Land50mg/Lwasnotsignificanttoo(P<0.05).Onthe
9
thday, thedensityofNannochloropsisoculatawassignificant
diferentbetween0mg/Land50, 100, 1 000 mg/L(P>0.05);
therewasasignificantdiferencebetween50 mg/Land100,
1 000mg/L(P<0.05);andthediferencebetween100 mg/L
and1 000 mg/Lwasnotsignificant(P>0.05).
ItwasrevealedinTable2 that, theKvalueofeachex-
perimentalgroupwassignificantlylowerthanthatofthecon-
trolgroup, whiletheGvalueofeachexperimentalgroupwas
significantlyhigherthanthatofthecontrol.Comparedwiththe
control, theKvalueofeachexperimentalgroupdecreasedby
7.59% andtheGvalueincreasedby8.22%whenL-carnitine
concentrationwas50mg/L;therewere13.46% decreaseof
Kvalueand15.56% increaseofGvaluewhenL-carnitine
concentrationwas100 mg/L;whenL-carnitineconcentration
was1 000 mg/L, itsKvaluedecreasedby13.58%, andG
valuewasincreasedby15.71%.WhenL-carnitineconcentra-
tionwas1 000 mg/L, theKvalueofNannochloropsisoculata
wassignificantlylowerthanthatoftheconcentrationof0 and
50 mg/L.ThedensityofNannochloropsisoculatabetween1
000 mg/Land0, 50 mg/Lweresignificantlydiferent, indica-
tingthat1 000 mg/LofL-carnitinehadsignificantinhibitory
effectsonthegrowthofNannochloropsisoculatapopulation.
Table1　DensityofNannochloropsisoculataunderdiferentconcentrationsofL-carnitine 104 /ml
Concentration∥mg/L Culturetime∥d
1 3 5 7 9
0(CK) 841±0a 1 375±100a 2 245±240a 3 258±590a 5 091±720a
50 841±0a 1 610±350a 2 326±810a 3 245±570a 4 440±670b
100 841±0a 1 343±680a 1 781±740a 2 600±320b 3 993±670c
1 000 841±0a 1 598±340a 2 148±480a 2 920±630b 3 990±980c
Thedatawerethemeansofthreerepetitions±standarddeviation.Thelowercaseinthesamecolumnwasmeaningthatthereweresignificant
diferencesatthe0.05levelbetweendiferenttreatments.
Table2　TheK, G/dvalueofNannochloropsisoculataunderdifer-
entconcentrationsofL-carnitine
Indexes Concentration∥mg/L
0(CK) 50 100 1 000
K 0.086 9 0.080 3 0.075 2 0.075 1
G/d 3.463 8 3.748 4 4.002 7 4.008 0
TheeffectsofdiferentconcentrationsofL-carnitineon
Tetrahymenaproliferation
Fourdiferentconcentrationsof0, 50, 100, 1 000 mg/L
weresettoinvestigatetheeffectofL-carnitineontheprolifer-
ationofTetrahymena.ItwasshownfromTable3 that, difer-
entconcentrationsofL-carnitinehadsignificantefectonthe
proliferationofTetrahymena(P<0.05).Onthe1stdayand
3
rdday, thedensityofTetrahymenabetweenthefourconcen-
trationswasnotsignificantlydifferent(P>0.05).Onthe5th
day, asignificantdifferenceinTetrahymenadensityexisted
between1 000 mg/Land0, 50, 100 mg/L(P<0.05);no
significantdifferenceinTetrahymenadensitywasfoundbe-
tween0mg/Land50, 100mg/L(P>0.05);onthe7thday,
Tetrahymenadensitybetween100, 1 000 mg/Land0 and50
mg/Lweresignificantlydifferent(P<0.05), whilenosignifi-
cantdifferencewasfoundbetween100mg/Land1 000 mg/L
(P>0.05);onthe9thday, Tetrahymenadensityhadsignifi-
cantlydifferencebetweentheforconcentrations(P<0.05).
Table3　TetrahymenadensityunderdifferentconcentrationsofL-carnitine ml
Concentration∥mg/L Culturetime∥d
1 3 5 7 9
0(CK) 247±2.70a 50±1.73a 62±4.71a 47±2.11a 61±4.58 a
50 247±3.12a 35±4.30a 62±4.72a 28±2.22b 23±2.18 b
100 247±1.25a 35±2.92a 65±5.03a 180±3.96c 301±4.40 c
1 000 247±2.49a 48±4.21a 80±7.62b 192±17.68c 404±32.60 d
Table4　TheK, G/dvalueofTetrahymenadensityunderdiferent
concentrationsofL-carnitine
Indexes Concentration∥mg/L
0(CK) 50 100 1 000
K -0.180 -0.121 -0.114 0.016
G/D -0.226 -2.469 -2.620 -18.580
　　AsitwasshowninTable4, theKvalueoftheexperi-
mentalgroupwassignificantlylowerthanthatofthecontrol
group, whiletheGvalueoftheexperimentalgroupwassignif-
icantlyhigherthanthatofthecontrol.Whentheconcentration
ofL-carnitinewas50 mg/L, theKvaluewasreducedby
32.78%, andGvalueincreasedby109.00%;whenL-carni-
tineconcentrationwas100 mg/L, theKvaluedecreasedby
63.00%andGvalueincreasedby117.00%;whenthecon-
centrationofL-carnitinewas1 000 mg/L, theKvaluewasre-
ducedby89.00%, Gvalueincreasedby82.00%.Theresult
suggestedthatL-carnitinecouldsignificantlypromotethe
growthofTetrahymenapopulation.
ThesignificantproliferationofTetrahymenacouldbere-
sultedfromthefolowingtworeasons:①L-carnitineinculture
mediumhadsomeefectsonNannochloropsisoculata, lead-
ingtothatNannochloropsisoculatasecretedacertainsub-
stance, whichcouldpromotethegrowthandpropagationof
Tetrahymena[ 7] .② L-carnitineintheculturemedium was
usedbywaterbacterialcommunitiesandprovidedcarbon, ni-
trogenandenergywhichwerenecessaryforthegrowthand
reproductionofbacteria, resultinginthattheTetrahymenaliv-
ingonwaterbacteriacommunitysignificantlyincreased.Cur-
rently, thestudiesontherelationshipamongprotozoa, bacte-
riaandthenecessarynutrientsforbacterialgrowthandrepro-
ductionhavebeenreported[8] .Forexample, theinternational
158 AgriculturalScience＆TechnologyVol.11, No.7, 2010
commonmethodofculturingciliateslivingonbacteriaisto
carryoutamixedcultureoffoodbacteriaandciliates, and
supplyrichmediumforbacteria, suchasbeefextract[ 9].In
thismixedsystem, thecarbon, nitrogenandenergywhichare
necessaryforbacterialgrowthandreproductionarederived
frombeefextract.Becauseproteinisthemaincomponentof
beefextractandothermedia, theratioofcarbontonitrogenis
imbalanceseverely, socarbonandenergysourcescanonly
relyontheaminoacidsmetabolism.Themetabolicpathway
notonlyreducesthesupplyofcarbonandenergyeficiency,
butalsoleadstotheaccumulationofammonia, thusinhibiting
thegrowthandreproductionofbacteriaandciliates.By
addingappropriateamountofglucosetothemedium, theratio
ofthecarbontonitrogencanberegulatedeffectively, tomain-
tainoptimumgrowthandreproductionofciliates.
Conclusions
TheapplicationresearchofL-carnitineonNannochlorop-
sisoculataandTetrahymenashowedthatL-carnitineatthe
concentrationsof50, 100, 1 000 mg/Lhadsomeinhibitory
efectsonhepopulationgrowthofNannochloropsisoculata
andcouldpromotethepopulationgrowthofTetrahymena.
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Responsibleeditor:YINQing-qing Responsibleproofreader:WUXiao-yan
左旋肉碱对微绿球藻和四膜虫种群生长的影响(摘要)
葛晨霞 ,董晓庆 ,候闯 ,张东鸣＊　(吉林农业大学动物科学技术学院 ,吉林长春 130118)
[目的 ]研究左旋肉碱对微绿球藻Nannochloropsisoculata和四膜虫 Tetrahymenasp.种群生长的影响。
[方法 ]对微绿球藻和四膜虫在左旋肉碱浓度为 0、50、100、1 000mg/L时的种群密度进行测定。
[结果 ]添加高剂量左旋肉碱对微绿球藻种群生长有显著抑制作用(P< 0.05);添加左旋肉碱对四膜虫种群生长有显著促增殖作用(P<0.05)。
[结论 ]该研究为左旋肉碱在水产养殖中的应用研究提供了理论依据。
关键词　左旋肉碱;微绿球藻;四膜虫;增殖
基金项目　国家自然科学基金(30671621)。
作者简介　葛晨霞(1975-),女 ,吉林长春人 ,硕士 ,高级实验师 ,从事水产养殖学研究。 ＊通讯作者,博士 ,教授 ,博士生导师,从事水产动物营养学
研究 , E-mail:dmzhang@jlau.edu.cn。
收稿日期　 2010-08-09　　修回日期　 2010-09-01
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2010年 10月 6日 , 《AgriculturalScience＆ Technology》
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159GEChen-xiaetal.EfectsofL-carnitineonPopulationGrowthofNannochloropsisoculataandTetrahymenasp.