& MEDICINE_Personal Portrait

Marine Passion

Instead of taking center stage as the prima ballerina she once wanted to be, Nicole Dubilier has become a star of the international science arena. The renowned scientist researches deep-sea and worms at the Max Planck Institute for Marine Microbiology in Bremen.

TEXT KLAUS WILHELM

hat a laugh! Over and Nicole Dubilier is sitting in her modest over again, Nicole office on the first floor of her institute Dubilier erupts into in Bremen. Pinned to the notice board peals of deep, hearty, is a card with birthday greetings from contagious, spirited, the crew of the Maria S. Merian, and a W congenial and loud laughter. She sim- humorous “baptismal certificate” for ply can’t help it, it seems. Even if – or crossing the equator on the high seas more precisely, when – she is talking from the crew of the Meteor. The sparse about the things that mean the world office contains just a few desks and to her: science, family and the ocean. shelves lined with specialist books and The joyful, downright exuberant bi- publications. The window overlooks the ologist from the Max Planck Institute institute garden and pond, and Bremen’s for Marine Microbiology adopts an Bürgerpark forest is visible in the dis- equally upbeat tone when recounting tance – it is easy to see how the view tales about her excursions in the Atlan- could provide a source of inspiration. tic and Pacific Oceans with the research “Nicole von Wurm,” as the ironic, yet Meteor, Sonne, and Maria S. Meri- highly symbolic nameplate on her office an, when explaining – that door reads, has been leading the now tightly knit “marriage of convenience” twelve-strong “Symbiosis” Research between various living – or Group from this office since 2007. the new world of molecular biology that is gradually unveiling the secrets MENAGE À TROIS BETWEEN that lie behind the phenomenon of A WORM AND TWO BACTERIA symbiosis, or when simply talking about bacteria and worms. Yes, worms! The livewire from the – Nicole Spontaneity and candor come just as Dubilier has been living in Hamburg easily to this down-to-earth woman as since the 1970s – has had a formative laughter – and research. She likes sto- influence on this research field over the ries and in general – and her own past decade. She was responsible for the life. All this is immediately obvious discovery of a new form of symbiosis: Photo: Björn Schwentker upon meeting her. a symbiotic menage à trois between a

62 MaxPlanckResearch 3 | 10 Letting her hands do the talking: When Nicole Dubilier addresses students in the seminar room, she does not rely on speech and humor alone. Her animated facial expressions and vivid hand gestures also help her get her message across.

3 | 10 MaxPlanckResearch 63 » BIOLOGY &MEDICINE 64 of animmersionheater. is milky-whiteandwoundlike thecoils waters. Underthemicroscope, itsbody ocean floorsofElba’s shallowcoastal through thesedimentof the sandy one totwocentimeterslong, burrows lier. Theexoticcreature,whichisjust ther: thatwouldnotsuitNicoleDubi- However, speciesei- itisnoordinary no posterspeciesofthemarineworld. chaete value ofadolphin,themarineoligo- ty ofawhaleandtheentertainment ing asitdoestheimpressivephysicali- not developuntillateroninlife.Lack- fascination thatliesintheunusualdoes dullindeed.” I musthavebeenvery us.” Dubilierlaughs:“Ifthat’s thecase, dullestamong inspire allbutthevery colors ofthetissuesarecoordinatedwill organization andorder, andtheway that: “Thevarietyofthestructures,their book onpracticalzoology, totheeffect “Kükenthal,” theseminalGermantext- omy, andreadthenotorioussentencein dissect anearthwormandstudyitsanat- semester biologystudents,shehadto likeallsecond- studies. Onthecontrary: intheearlystagesofherbiology did shedevelopanygreatpassionforthe how theyregeneratedthemselves,nor sected earthwormsasachildtowatch things wouldturnout:shehadnotdis- years hadsuggestedthatthiswashow counts Dubilier. Nothinginherearly denly changedmyscientificlife,”re- an shoresoftheislandElbathat“sud- tremely proudatthetime.”Shelaughs. world ofscientificresearch. “Iwasex- – theequivalentofaknighthoodin a letterintheprestigiousjournalN merited partners benefit.Thediscovery topreviousbelief,allofthe contrary worm andtwobacteria,fromwhich, MaxPlanckResearch MaxPlanckResearch Sometimes anappreciationforthe It wasawormfromtheMediterrane- strong-willed woman finally received herdoctorate. received womanstrong-willed finally alongsix-year on. and After carried she herteeth struggle, determined gritted the and occasions, different On three Dubilier tempted tothrow in was towel, the buteach time Olavius algarvensis 3 | 10 _Personal Portrait

isclearly ATURE

they assimilatedbacteriathatchemical- trick: atsomepointintheirevolution, this riskwiththehelpofaningenious almost allanimals.Thetubewormsdefy ten eggssmellbadandispoisonousto ,thegasthatmakesrot- of theEarth.Thesoupisfortifiedwith that spewahellishsoupfromthedepths ers atboilinghothydrothermalvents bottom ofthedeepsea–onblacksmok- scientists discoveredtubewormsatthe As farbackastheearly1980s,American PROXIMITYSOURCE TO FOOD THE THE HOSTGUARANTEES ammonium andurea. the excretionofwasteproducts,suchas body invainforkidney-likeorgans The anatomistwouldalsosearch its fact, itlacksadigestivetractaltogether. stomach norintestinebowels.In well.Ithasneithermouthnor very does noteatabiteoffood,yetitlives unusual features.Themarineworm fact thatdoeslittlejusticetoitshighly It isrelatedtothelowlyearthworm,a representative oftheworldworms. just 0.2millimeters,itisatrulysvelte Olavius Dubilier’s doctoralsupervisor, Olav drothermal venttubeworms, Nicole their mutualbenefit. formed bytwolivingorganisms for of nutrition.Inshort:acommunity constant proximitytotheirsource ishment, thehostguaranteesitsguests lationship as,inreturnforthenour- more thanaclassicalsymbioticre- bon. Theentirespectacleisnothing they usetofixCO al “sulfideoxidizers”obtainenergythat render itharmlesstothem. ly convertthehydrogensulfideandthus Soon after the discovery ofthehy- Soon afterthediscovery Through thisprocess,thesebacteri- isalsoslim:withadiameterof 2 intoorganiccar - host bacteria. sulfide-rich sedimentandappearedto Bermuda. Thesewormsalsothrivedin not inthedeepsea,butoncoastof ingutlesswormsthathefound, asimilarsymbioticrelation- observed Giere fromtheUniversityofHamburg, shower. Onthree differentoccasions, muse onitcreativelywhile takinga grossed bytheirsubjectthat theyeven researcher, someonewhoissoen- shattered: thatofbecoming afulfilled next dreamalsoappeared tohave doing herdoctorate,however, the dream offulfillment.Whileshewas lively mindandsharpintellect. aspectoflifewitha approaches every woman isjudiciousinheractions.She been overbytheageof30anyway.” This And, “mydancingcareerwouldhave , andemptychatternolessso. girls.” Alossforwordsisforeigntoher sensible conversationwiththoseballet the time.“Itwasimpossibletohavea interestedinthepoliticsof became very changed.Asateenager,everything she of therenownedStuttgartBallet.Then tion fortheprestigioustrainingschool She evenpassedtheentranceexamina- afternoonafterschool. let barreevery with unwaveringdedicationatthebal- age of15.Priortothat,shehadpracticed of becomingaclassicalballerinaatthe passion andfulfillment.Andnowthis! ly believedthatacareershouldinvolve cloud,” shelaughs.Shehadalwaysfirm- miserable. “Ihadmyownpersonalrain Sylt, whereshedidherfieldwork,was weather onthenorthGermanislandof she founditratheruninspiring.The Although thetopicconcernedworms, which involvedaphysiologicalstudy. struggling withherdoctoralthesis, Meanwhile, NicoleDubilierwas Nonetheless, sheheldontoher She had given up on her first dream She hadgivenuponherfirstdream

Photo: Björn Schwentker (top, 2), MPI for Marine Microbiology 1 2

1 The microtome is a device for cutting extremely thin sections of material embedded in a block of wax. 2 Nicole Dubilier rarely finds the time to tinker with the microtome 3 Well nourished despite the lack of a digestive tract: Olavius algarvensis, an oligochaete and relative of the earthworm, might not have a mouth or digestive system, but that does not mean it has to starve. The , which is only about two centimeters long, has bacterial endosymbionts to thank for this.

3

3 | 10 MaxPlanckResearch 65 1

1 Dialogue in the institute’s Lander workshop: Nicole Dubilier discusses improvements to the equipment with the sea technician, Marc Viehweger. 2 Laughter is an essential part of the process: Nicole Dubilier clearly enjoys her work. 3 Looking back at the last sea voyage: Nicole Dubilier discusses a map with a field on the Mid-Atlantic Ridge with some members of her team – (from left) Caroline Verna, Karina van der Heijden, Silke Wetzel and Dennis Fink.

2 3

66 MaxPlanckResearch 3 | 10 BIOLOGY & MEDICINE_Personal Portrait

» The eldest of four children, Nicole Dubilier comes from a distinguished background. Her father was an American businessman and her mother a descendant of the renowned Berlin physiologist Emil du Bois-Reymond and Fanny Mendelssohn, sister of composer Felix Mendelssohn-Bartholdy.

Dubilier was tempted to throw in the teria and primitive protozoa, in partic- She was born in New York and grew up towel, but each time she gritted her ular, fueled the spread and of on the Upper East Side, one of the Big teeth and carried on. plant and animal cells, and shaped the Apple’s most illustrious neighborhoods. After a long, six-year struggle, the development of life on Earth. There’s no doubt about it: the eldest of determined and strong-willed woman Today, almost all plant, animal and four children, Nicole Dubilier comes finally received her doctorate in 1992. human cells, with their minute energy from a distinguished background. Her It was clear to her, however, that she power plants, the mitochondria, still father was an American businessman would not be able to survive many contain the descendents of earlier bac- and her mother a descendant of the more years like this, as “it is frustrating terial symbionts – without mitochon- renowned Berlin physiologist Emil du when you work hard and remain unful- dria, we would not be able to breathe. Bois-Reymond and Fanny Mendelssohn, filled.” The plan: “I’ll give myself one Dubilier explains that innumerable sister of the composer Felix Men- more year as a post-doc,” working on a bacteria thrive in the human bowels delssohn-Bartholdy. Creativity is clearly different topic, doing a different kind and return the favor by supporting di- in her blood. of research. She would soon know if it gestion, or possibly even strengthening Her German mother emigrated to really gratified her: it would have to feel the immune system. Symbioses can be the US in the 1950s and married there. like ballet. found wherever you look. “An explosive union from the outset,” It turned out to be molecular biolo- It may thus come as some surprise is how the daughter describes the mar- gy, or more specifically, the symbiosis to learn that symbiosis only gradually riage. “My parents were like fire and between worms and bacteria, that pro- took off as a research field in the mid- water, and it was all quite chaotic.” vided the satisfaction she sought. Mo- 1990s. To enable scientists to find out The family moved to Germany in the lecular biology provided the right path more about the emergence of these 1970s, to Wiesbaden, where Nicole because, in a way, it is less tedious than partnerships, as simple a model as pos- Dubilier completed her German high . “When it works, that’s it. sible was needed. Olav Giere’s gutless school studies at the nationally re- You don’t have to repeat the experi- shallow-water Bermuda worms ap- nowned Helene-Lange-Schule, achiev- ment five times,” says the researcher. peared tailored to this task. With the ing an excellent grade average. “I real- What fascinated her about symbiosis worm cultures in her suitcase, Nicole ly enjoyed school,” she says. And it was the idea of cooperation; the fact Dubilier headed off to Harvard Univer- wasn’t just physics, chemistry and bi- that evolution is not driven solely by sity, to Colleen Cavanaugh’s laborato- ology that appealed to her – she was egoism and competition, and that co- ry, which had made a crucial contribu- also fascinated by politics, the social operation and reciprocity can also be tion to the discovery of the deep-sea sciences and humanities. Discussion, the engine of evolution. In this life tubeworms with their bacterial symbi- protest, conflict: the young Nicole Du- form, each participant contributes onts. It was in this prestigious setting bilier was interested in social develop- something that helps the other partic- that Nicole Dubilier became familiar ments, and still is today. ipant. “That touched me,” she says. “So with the tools of molecular technology. Against this background, her choice much so that it grieved me when some of biology as a subject is rather surpris- symbionts “cheated” on their partners.” CREATIVITY IN HER BLOOD ing. But “I also wanted to do something This could be interpreted as a typi- with my hands, something that linked cally female perspective on things: co- The move to Harvard also marked a re- physical and mental work.” So biology operation instead of egoism. However, turn to her native country: Nicole Dubi- it would be, preferably marine biology. Nicole Dubilier counters such an inter- lier is American by birth, with an inter- Her love of the sea runs deep and was pretation with hard facts and the con- esting and eventful biography. Her forged by annual two-month-long fam- viction of an inspired researcher. She original nationality is not immediately ily holidays on Fire Island, a long nar- goes on to explain how symbiosis is an obvious to anyone who hears her chat row island off the shore of Long Island. ancient process: without symbiosis, life in perfect Hanseatic German. However, “Paradise for us children.” Her choice would not have been able to develop a slight American accent creeps into her of subject was also influenced by an-

Photos: Björn Schwentker (3) on Earth. The symbiosis between bac- energetic Hamburg German at times. other important factor: “Given the cha-

3 | 10 MaxPlanckResearch 67 BIOLOGY & MEDICINE_Personal Portrait

» When she gets together with her colleagues as she does this afternoon, the atmosphere is constructive and friendly. The topic of discussion is the next trip to the Mid-Atlantic Ridge with the Meteor – a major event for all.

otic family life I experienced, I wanted rium that produces sulfide from sulfate Atlantic Ridge with the Meteor – a ma- to find order and logic somewhere. In and generates energy in the process. jor event for all. Meticulous prepara- science, I thought, two plus two always The familiar sulfide-oxidizing bacteria tion is required. And when, as now, equals four.” A young seeker of the sim- use the hydrogen sulfide in turn as a they all beat around the bush because ple truth. She laughs. source of energy. they don’t want to take over a routine She would later come to understand A cycle thus emerges in which the task, the boss can also show her asser- that research only really becomes fasci- two bacterial species exchange their tive side: “This has to be settled now, nating when two plus two appears to metabolic products and ends only with who’s going to do it?” She laughs. make five – at the latest by the time she the death of the host. This biological Together with partners from the reached Harvard. Resolving such contra- construct functions so admirably that institute in Bremen and other insti- dictions carries the promise of scientific the bacteria produce an excess of organ- tutes in Germany and abroad, Dubili- renown – as was the case in the late ic carbon compounds from carbon di- er and her team regularly deliver out- 1990s when Olav Giere and Swedish tax- oxide, with which they feed the worm. standing results. The researchers have onomist Christer Erseus accidentally dis- The microbes also relieve their host of carried out in-depth studies on the covered Olavius algarvensis off the is- all of the inconvenient waste products “O. algarvensis biotope” using new land of Elba. The find immediately that it would otherwise have to excrete. molecular methods, and identified up presented a puzzle: no matter how thor- “Simply ingenious,” says Nicole Dubi- to four different bacterial species, a oughly Nicole Dubilier looked, she lier. The worm makes itself largely in- ménage à plusieurs involving two sul- could not detect hydrogen sulfide in the dependent of external energy sources fate reducers and two sulfide oxidizers. sediment of Capo Sant’Andrea Bay. All and can populate new habitats that Surprisingly, all four symbionts fix previously discovered gutless oligochae- have little to no sulfide. “My most im- carbon dioxide. Why the redundancy? te worms (annelids) lived in sulfide-rich portant scientific contribution – and no That remains unclear. sediments. Moreover, electron micro- one believed it at first.” But the doubt- scope images testified that at least two ers were silenced. A MODEL FOR A SELF- morphologically different bacterial spe- Not least as a result of this discovery, SUSTAINING BIOSPHERE? cies lived inside the worms. Nicole Dubilier settled for the long-term Nothing added up correctly until at the Max Planck Institute in Bremen The different metabolic systems may Nicole Dubilier decoded the symbiont’s in 2001. “I had always wanted to work perhaps be used in different sediments, 16s rRNA gene. This gene is considered at this institute because it offers in predominantly oxygen-rich upper by experts to be a kind of molecular optimum working conditions.” These layers of sand and in predominantly ni- passport for a bacterial species. This led include her own research group – she trate-rich deeper layers of sand. What to a pioneering discovery for symbiosis now has her own funding as a research is clear is that the worm has a regular research: a harmonious menage à trois – organizer – an office instead of a labora- symbiotic powerhouse built into its one host with two symbionts, with all tory, and the opportunity to develop body. “O. algarvensis shows how limit- of the partners benefiting. new perspectives with her colleagues. ed resources can be used through the “They’re great,” she says warmly. “The cooperation of microbial communities A DISCOVERY THAT SILENCED teamwork is great fun.” Just what you’d that are tailored to each other’s needs,” THE DOUBTERS expect from a symbiosis researcher. explains Nicole Dubilier. The worm- When she gets together with her bacteria symbiosis could thus provide a Because there is little or no hydrogen colleagues, as she does on this particu- model for an almost self-sustaining bio- sulfide in the Mediterranean sediment, lar afternoon, the atmosphere is con- sphere. Such systems are required on a O. algarvensis internalized a source of structive and friendly. The topic of large scale by space travel, for example hydrogen sulfide by taking up a bacte- discussion is the next trip to the Mid- for long expeditions to Mars.

68 MaxPlanckResearch 3 | 10 Photos: Björn Schwentker (2) tion,” saysNicoleDubilier. Hercol- how provideprotectionagainst infec- assume thatthesymbionts can some- do nothavesymbionts.“We therefore penetrate intothenucleiof cellsthat cells. Interestingly, these parasitesonly teria thatinfectthenucleiofmussel Max Planckteamalsodiscoveredbac- containing oxygenandsulfidestothem. constantly pumpamixtureofseawater onts incertaincellsoftheirgillsand found. Theycultivatebacterialsymbi- seeps wherehydrogensulfidecanbe corpses, hydrothermalventsandcold a rathermiserableexistenceonwhale field forDubilier. out Thebivalvescarve of thedeepseaisacomparativelynew free fromthetiesofappliedresearch. to keepaneyeoutfortheunexpected, er likestoenterunknownterritory, and More thananythingelse,NicoleDubili- tant forinfectionresearch. Yes, thattoo. symbiotic bacteriacouldalsobeimpor- many oftheprocessesassociatedwith linked tospeciesdiversity, aswellhow the well-beingofseaisdirectly carbon budgetoftheoceansandhow Shethenexplainsabitaboutthe serve. her “symbiosisscience”couldpossibly asked questionastowhatpurpose amples inresponsetotherepeatedly Nicole Dubilieralwaysreferstosuchex- While studyingthissymbiosis,the The research of musselsinthedark a classical ballerina at the age of 15. A few years later, she embarked on an extremely successful career in marine biology. inmarine career successful extremely an on embarked later, she years Afew 15. of age the at ballerina a classical becoming of dream her up gave she However, young, was she when ballet of didalot Dubilier Nicole stage: scientific the On UNDERWATER WORLD FASCINATING IMAGES FROM THE ocean windinherface. Meteor to setsailatleastonceayearwiththe ocean.” Sheperceives itasaprivilege light up:“Iamsimplyhappyonthe diately makesNicoleDubilier’s eyes excursion totheworld’s oceansimme- though, ofcourse,themereideaan cess thantheirdeep-searelatives.Al- shallow-water musselsareeasiertoac- commercially availablebluemussels. presence ofsuchnuclearinfectionsin well, it’s greatfun,andwhenitdoesn’t – mainlymusselsoflate.“When itgoes ment usingtheROV’s manipulatorarm they shouldfishfromtheocean sedi- asm. Itisherjobtotellthepilots what self,” shesays,withobvious enthusi- “It’s likesittinginthemiddleofityour- screen showingtheimagesitcaptures. who flytheROV, watchingthelarge small darkcontainerwiththepilots the seaandscientistsitsin ed vehicle(ROV)divestothebottomof when theunmannedremotelyoperat- hard. Itstartsearlyinthemorning lifeonboardissometimes But everyday nomenon somewhatlessdifficult,as leagues havenowdemonstratedthe This makesresearching thisphe- orthe Merian , andtofeelthe She laughs.Ofcourse. doing thebestresearch intheworld.” just wantstobeablesay“my teamis til she’s 80,ifshe’s allowedto.Andwho power-woman whowantsto workun- lar biologistandmicrobiologist, the lier: mother, marinebiologist,molecu- stuck tothedeal.”That’s NicoleDubi- share childcareequally, andwe’ve agreed withmyhusbandthatwewould fosters theideaofcooperation.“I “He’s wonderfulatit.”Here,too,she over thechildcaringinherabsence. she knowsthatherhusbandwilltake eight fouryearsago.Andonlybecause such tripsagainsincehersonturned equally exhaustedcolleagues. er foranearlymorningchatwithher shegetstogeth- tired andbleary-eyed, ter 20hoursofhardtoil,completely ing.” Andshelovesthetimeswhen,af- smells ofsulfideisincrediblysatisfy- hands andsniffingittoseewhether sel fromthedepthsofoceaninyour job cantakeallnight.“Holdingamus- around alaboratory,” saysDubilier. The when theyseethatIstillknowmyway oratory. “Mycolleaguesaresurprised animals andmicrobesintheship’s lab- searchers, preparing andanalyzingthe up again,theworkcontinuesforre- evening, whentheROVhascomeback go sowell,youbicker.” Andinthe She hasonlybeenparticipatingin 3 | 10 MaxPlanckResearch MaxPlanckResearch 69