survival-of-filamentous-fungi-in-hypersaline-dead-sea-water

SurvivalofFilamentousFungiinHypersalineDeadSeaWaterT.Kis-Papo,1A.Oren,2S.P.Wasser,1,3E.Nevo11InstituteofEvolution,TheUniversityofHaifa,Mt.Carmel,Haifa31905,Israel2DivisionofMicrobialandMolecularEcology,andtheMosheShiloMinervaCenterforMarineBiogeochemistry,TheHebrewUniversityofJerusalem,Jerusalem91904,Israel3KholodnyInstituteofBotany,NationalAcademyofSciencesofUkraine,TereshchenkivskaStr.2,01001Kyiv-MSP-1,UkraineReceived:19August2002;Accepted:9October2002;Onlinepublication:28January2003ABSTRACTAvarietyoffilamentousfungihaverecentlybeenisolatedfromtheDeadSea(340g/Ltotaldissolvedsalts).ToassesstheextenttowhichsuchfungicansurviveforprolongedperiodsinDeadSeawater,weexaminedthesurvivalofbothsporesandmyceliainundilutedDeadSeawaterandinDeadSeawaterdilutedtodifferentdegreeswithdistilledwater.MyceliaofAs-pergillusversicolorandChaetomiumglobosumstrainsisolatedfromtheDeadSearemainedviableforupto8weeksinundilutedDeadSeawater.FourDeadSeaisolates(A.versicolor,Eurotiumherbariorum,Gymnascellamarismortui,andC.globosum)retainedtheirviabilityinDeadSeawaterdilutedto80%duringthe12weeksoftheexperiment.MyceliaofallspeciessurvivedforthefulltermoftheexperimentinDeadSeawaterdilutedto50%and10%ofitsoriginalsalinity.ComparisonofthesurvivalofDeadSeaspeciesandcloselyrelatedisolatesobtainedfromotherlocationsshowedprolongedviabilityofthestrainsobtainedfromtheDeadSea.SporesofisolatesobtainedfromtheterrestrialshoreoftheDeadSeagenerallyprovedlesstoleranttosuspensioninundilutedDeadSeawaterthansporesofspeciesisolatedfromthewatercolumn.SporesofthespeciesisolatedfromthecontrolsiteshadlosttheirviabilityinundilutedDeadSeawaterwithin12weeks.However,withtheexceptionofEmericellaspores,whichshowedpoorsurvival,asubstantialfractionofthesporesofDeadSeafungalisolatesremainedviableforthatperiod.Thedifferenceinsurvivalratebetweensporesandmyceliaofisolatesofthesamespeciespointstotheexistenceofadaptedhalotolerantand/orhalophilicfungiintheDeadSea.IntroductionTheDeadSeaisoneofthemostextremehabitatsformicroorganismsonEarth