potential-of-halotolerant-and-halophilic-microorganisms-for-biotechnology

MINI-REVIEWExtremophiles(2001)5:73–83DigitalObjectIdentifier(DOI)10.1007/s007920100184©Springer-Verlag2001R.Margesin(�*)•F.SchinnerInstituteofMicrobiology(NF),UniversityofInnsbruck,Technikerstrasse25,A-6020Innsbruck,AustriaTel.+43-512-5076021;Fax+43-512-5072929e-mail:rosa.margesin@uibk.ac.atPotentialofhalotolerantandhalophilicmicroorganismsforbiotechnologyAbstractHalotolerantorhalophilicmicroorganisms,abletoliveinsalineenvironments,offeramultitudeofactualorpotentialapplicationsinvariousfieldsofbiotechnology.Thetechnicalapplicationsofbacteriorhodopsincompriseholography,spatiallightmodulators,opticalcomputing,andopticalmemories.Compatiblesolutesareusefulassta-bilizersofbiomoleculesandwholecells,saltantagonists,orstress-protectiveagents.Biopolymers,suchasbiosurfac-tantsandexopolysaccharides,areofinterestformicrobiallyenhancedoilrecovery.Otherusefulbiosubstancesareenzymes,suchasnewisomerasesandhydrolases,thatareactiveandstableathighsaltcontents.Halotolerantmicro-organismsplayanessentialroleinfoodbiotechnologyfortheproductionoffermentedfoodandfoodsupplements.Thedegradationortransformationofarangeoforganicpollutantsandtheproductionofalternativeenergyareotherfieldsofapplicationsofthesegroupsofextremo-philes.KeywordsHalotolerant/halophilic•Biotechnology•Bact-eriorhodopsin•Compatiblesolutes•Biopolymers•Halo-fermentation•Wastetreatment(biodegradation)IntroductionAsaresultofadaptationtotheirenvironment,manyextre-mophilicmicroorganismshaveevolveduniquepropertiesofconsiderablebiotechnologicaland,therefore,commercialsignificance.Theobjectiveofthisreviewistosummarizethebiotechnologicalpotentialofhalophilic/halotolerantmicroorganisms,focusingonrecentdevelopmentsinthisarea.Thetaxonomy,physiology,andbiochemistryoftheseorganisms,partlyincludingapplications,havebeenreviewedbyGalinskiandTindall(1992),Eisenbergetal.(1995),Grantetal.(1998),Ventosaetal.(1998),andOren(1999).Briefly,therearetwostrategiestocopewithasalineenvironment.HalophilicArchaeamaintainanosmoticbal-anceoftheircytoplasmwi