ScholarlyJournalofBiologicalScienceVol.2(3),pp.30-38,March2013Availableonlinehttp://www.scholarly-journals.com/SJBSISSN2315-6147©2013Scholarly-JournalsFullLengthResearchPaperReductionofcholesterolbyLactococcuslactisKF147WesamA.Hassanein,NadiaM.AwnyandShimaaM.Ibraheim*DepartmentofBotany,FacultyofScience,ZagazigUniversity,Zagazig,44519,Egypt.Accepted17January,2013Lactococcuslactisfromyoghurtsamplewasconfirmedbasedonalignmentof16SrRNAgenesequenceingenebank.Thedegreeofacidandbiletoleranceofbacteriawasevaluated.L.lactisKF147wasabletomaintainviabilityfor2hatpH2andgrewinamediumof4,000mg/Lbileacidswithmaximumcholesterolreductionof66.8%fromtheculturemedium.ThefattyacidcompositionofthecellsofL.lactisKF147wasalteredbyreducingcholesterolfromthemedia.Infraredspectroscopy(IR)analysisandtransmissionelectronmicroscopeweredetectedinthecholesterolbindingactivitybetweenL.lactisKF147andcholesterol.TherestinganddeadcellsofL.lactisKF147exhibitedthecholesterolreducingactivityof32.9and29.7%,respectively.Keywords:Binding,cholesterol,LactococcuslactisKF147,reduction.INTRODUCTIONCholesterolisakindofsteroid,foundparticularlyinanimalcellmembranes(Paniangvaitetal.,1995).Cholesterolcirculatesinbloodasacomponentoflipoproteins(Bansaletal.,2005).Majorityofthecholesterolsynthesizedcomesfromtheliver(Kimetal.,2003).Cholesterolintheintestinecomesfromdiet,bile,andintestinalsecretions(Levyetal.,2007).Cholesterolisrequiredfortheformationofsexhormones(Young,2001),cellmembranefunction,formationofvitaminDintheskin(MoserandSavage,2001)andbileacids(AfafandAli,2009),precursorforhormonesandvitamins(Ikonen,2006),andinaddition,playsavitalroleinthedevelopment,functionandstabilityofsynapses(ChattopadhyayandPaila,2007),andpathogenesisofHumanImmunodeficiencyVirus(HIV)infectionanddiseaseprogression(Mansfieldetal.,2007).CholesterolreductionbymicroorganismstakesplacebydifferentmechanicalbioactivitieswhichincludetheinhibitionofthehydroxymethylglutarylcoenzymeAreductase(Homma,1988),co-precipitation(KlaverandVanderMeer,1993)oruptakeandco-precipitationofcholesterolbybacteria(Tahrietal.,1996),productionforcholesterolesterase(Young,2001)andprecipitationofcholesterol(Saavedraetal.,2004).Inaddition,*Correspondingauthor.E-mail:Dr_shimaa199@yahoo.com.cholesterolbindingtocellwallsofprobiotics(LiongandShah,2005),co-precipitationofcholesterolwithdeconjugatedbile(LiongandShah,2006),productionofshortchainfattyacidsuponfermentationbyprobioticsinthepresenceofprebiotics(DePreteretal.,2007),extracellularcholesteroloxidaseenzyme(Mendesetal.,2007),enzymaticdeconjugationofbileacidsbybile-salthydrolaseofprobiotics(Lambertetal.,2008),incorporationofcholesterolintothecellularmembranesofprobioticsduringgrowth(Lyeetal.,2010a)andconversionofcholesterolintocoprostanol(Lyeetal.,2010b).Somemicroorganismsassimilatedcholesterolgrowsoncholesterolasasolecarbonsource.Thenon-pathogenicandpathogenicmycobacteriaareabletousecholesterolasasolecarbonsource(GayandSobouti,2000).Kovalenkoetal.(2004)observedthat,thestrainsoflacticacidbacteriastrain,N139belongingtoLactobacillus,Streptococcus,EnterococcusandLeuconostocgenerahaveusedcholesterolascarbonsource.Probioticshavebeenconsideredtohavepotentialhealth-promotingbenefitsasbiotherapeuticagentsorabiologicalhypocholesterolemicagent(Parketal.,2007),andhavecholesterolloweringeffectsinaqueoussystemasliquidmedia(Saavedraetal....
