Zooplankton for the production of biomass in Bioregenerative Life Support Systems (BLSS) in space

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1 M. Knie, C. Laforsch Zooplankton for the production of biomass in Bioregenerative Life Support Systems (BLSS) in space 51 st ESLAB SYMPOSIUM ESTEC

2 Bioregenerative Life Support Systems (BLSS) independency of regular supply (long term missions/ Mars exploration) kerbalspaceprogram.com renewal of atmosphere and water food production conversion of organic waste into nutrients for the production of biomass Verseux et al

3 3 Bioregenerative Life Support Systems (BLSS) based on real ecosystems natural nutrient cycle trophic levels aquatic systems aquatic organisms better adapted to diminished gravity conditions

4 4 Daphnia magna in BLSS link between primary prodcution and higher trophic levels parthenogenetic reproduction Ø clones short generation time (maturity:6 days; new offspring: 3days) high reproduction rate (up to 80 eggs per brood) biomass

5 5 Daphnia magna in BLSS indicator for water quality (OECD model organism for ecotoxicology) production of dessication resistant dormant eggs (ephippia) Ø restart after population breakdown possible

6 6 Heterocypris incongruens in BLSS extremely tolerant of changing environmental conditions (temperature, ph, O 2 concentration, etc) rapid and high increase in biomass Lindholm/ Hobæk Norskinstitutt for vannforskning feeding on decaying organic matter production of dessication resistant dormant eggs Ørestart after population breakdown possible

7 7 Research prior to the use in BLSS analyse response of organisms to microgravity (weightlessness) locomotion behaviour and behavioural adaptation feeding interactions between organisms from different trophic levels identify and study the mechanisms of spatial orientation and graviperception impact of microgravity on physiological and cellular level

8 8 Locomotion behaviour in microgravity Daphnia magna loop swimming Heterocypris incongruens loop swimming (a) passive drifting (b) a b

9 9 Threshold of graviperception Daphnia magna Heterocypris incongruens loop swimming [%] loop swimming [%]

10 10 Behavioural adaptation to µg Daphnia magna mean looping duration seconds microgravity

11 11 Behavioural adaptation to µg Heterocypris incongruens mean looping duration seconds microgravity

12 Feeding in microgravity filter feeder Daphnia magna Heterocypris incongruens foraging on food particles in sediment and benthic zone Beat frequency of the thoraric limbs of adult D. magna during (µg) and shortly before (1g) catapult shots at ZARM drop tower. Duration of feeding behaviour under differing gravity (µg and 1g) and illumination conditions (darkness [infrared light] and white light) 12

13 13 Predator-prey interactions in µg fleaworld.be esf.edu

14 Predator-prey interactions in µg Chaborus Triops cancriformis ambush predator cruising predator D. cucullata able to recognize predator by infochemicals no co-occurrence with D. cucullata less movements reduce possibility of encounter D. cucullata no predator recognition 14

15 Predator-prey interactions in µg number of attacks with subsequent feeding on prey Chaoborus Triops 1 5 D. cucullata 15

16 16 Graviperception in Daphnia magna postabdominal setae

17 17 Graviperception in Daphnia magna sinking reception = indirect gravi-sensing gravity does not directly act on gravi-sensing organ but on body of the animal, deflection of setae by water resistance

18 18 Impact of microgravity on molecular level in Daphnia magna no data on the impact of microgravity on the molecular level so far important aspect in the context of BLSS as altered gene expression might impede survival and reproduction of Daphnia Ø disruption of food chain, non-functional BLSS

19 19 Impact of microgravity on molecular level in Daphnia magna Altered gravity induce changes in gene expression 3- fold up-regulated 3-fold down-regulated

20 20 Impact of microgravity on molecular level in Daphnia magna modified expression of gene which are associated with functions, biological processes and cellular components, such as up-regulated ion transport protein refolding unfolded protein binding cellular process metabolic process membrane protein kinase activity down-regulated metabolic process primary metabolism extracellular region structural constituent of cuticle heme binding reproduction

21 21 Impact of simulated microgravity on the proteom of Daphnia magna actin binding protein binding energy metabolism hemoglobin

22 22 Conclusion I µg -> changed swimming behaviour -> no clear indication of behavioural adaptation However on-board space station MIR -> survival and reproduction during 4 months partial compensation by phototactic orientation stimulus possible indication of different threshold values of the perception of gravity identification of the primarily graviperceptive structures in D. magna

23 23 Conclusion II hyper-g and µg lead to modified gene expression long-term effects on organisms cannot be ruled out Simulated microgravity leads to altered proteins consequences for survival and reproduction not yet evaluated Nakanishi et al Otte et al bio.indiana.edu

24 24 Outlook I further studies on gene expression and proteome under altered gravity conditions and comparison of data from different platforms (suborbital flight, drop tower) different exposure times/ accelerations reference experiments with hypergravity/ simulated microgravity

25 25 Outlook II characterization of graviperceptive organs and processes in other zooplankton organisms (especially ostracods and copepods) morphological analysis functional characterization interplay of gravi- and phototactic orientation determination of the threshold value of gravity perception Ø Comprehensive analysis of different zooplankton organisms to select suitable candidates for BLSS

26 Thank you for your attention! 26