Bioluminescent Sensors for Space Ecosystems Li 1 Yang , 2 Kratasyuk Valentina 1SLSTP Trainee, Carnegie Mellon University, Pittsburgh, PA, 15213, 2Professor of Biophysics, Krasnoyarsk State University, Krasnoyarsk, Russia Objectives Light Intensity Signal These two bioluminescent tests were assessed on the PerkinElmer Victor2 Bioluminometer along with environmental samples from Kennedy Space Center (KSC). Development of Bioluminescent Test Systems This experiment establishes standard experimental procedures for conducting bioluminescent tests to monitor contaminants in the water and air of closed environments. Effect of Common Toxins on Bioluminescent Detection Systems Methods Results and Discussion The standard reaction mixture of coupled enzyme system was determined: 10 µl 0.002% tetradecanal, 5 µl 0.04 mM FMN, 2 µl Luciferase-Oxidoreductase, 20 µl Phosphate buffer, 10 µl NADH.. Bioluminescent Assessments of Environmental Samples Fig 1. Effect of Ethanol on E.coli Luminous Bacteria Water Filtration Assessment 180000 1400000 Luminous Bacteria [10 µl] Luminescencee 140000 Fig 6. Bioluminescent Assay of the Capacity of Filters to Eliminate Bacteria Luminous Bacteria [20 µl] 120000 Luminous Bacteria [40 µl] 100000 Luminous Bacteria [60 µl] Luminous Bacteria [80 µl] 80000 Luminous Bacteria [100 µl] 60000 Luminous Bacteria [120 µl] 40000 Luminous Bacteria [140 µl] 20000 0 -20000 0 5 10 15 20 25 Ethanol [µl] 10000000 1000000 100000 10000 1000 100 10 1 Fig. 3 Liquid Butenol on the Coupled Enzyme System 7000000 600000 6000000 500000 Luminescence Luminescence 700000 400000 300000 200000 100000 0 2 4 6 8 10 Air 100 µl 800000 Buthenol Gas 600000 400000 0 50 100 Broth 10^-6 10^-5 10^-4 10^-3 10^-2 10^-1 1 0 2 4 6 Gas [µl] Water Filtered Water 10000000 0 0 1 2 3 4 5 6 Buthenol [µl] Bacteria 1000000 Acknowledgements 100000 10000 1000 100 100000 10 10000 1000 1 The sensitivity of luminous bacteria and the enzyme system to ethanol (1 µl) was more than for butanol (2 µl) (Fig. 2,3). Therefore, 1µl of ethanol would be used for further experiments. The bioluminescence tests found that 1/3 hoaglands nutrient Obtaining the Coupled Enzyme Reaction Mixture water collected from the environmental chambers at KSC had Fig 4. Influence of Ethanol on Aldehyde no toxicity effects on the biological test system (Fig. 7); filtered and unfiltered water showed the same light intensity emissions. 0 100 200 400 600 800 1000 1200 1400 1600 Time [s] 10 1 0 10^-6 10^-5 10^-4 10^-3 10^-2 10^-1 1 Bacteria Concentration Soil Seed Medium Bioluminescent Assessment A Nutrient Plant Soil Seed Medium was investigated by a luminous bacteria assay (Fig. 13, 14). Fig 5. Influence of Ethanol on FMN 1400000 600000 Ethanol 1 µl 400000 200000 Ethanol 1 µl Fig 9. Luminescence of Concentrations of E.coli Luminous Bacteria 400000 Fig 8. Optical Density of Concentrations of E.coli Luminous Bacteria 10 15 20 25 30 FMN [µl] Light emission intensity was dependent on tetradecanal aldehyde and FMN concentrations (Fig. 4, 5). Ethanol was found to compete with tetradecanal as it reduced the intensity of light emissions with increasing concentrations of aldehyde. This suggests that ethanol acts to disrupt tetradecanal activity in the enzymatic reaction. Ethanol did not influence the FMN substrate activity. 1000000 1500000 1000000 10000000 1.2 1000000 1 500000 0.8 0 100000 Optical Density Aldehyde [µl] 5 Luminescence 8. 5 10 .5 12 .5 14 .5 16 .5 18 .5 20 .5 22 .5 6. 5 4. 5 2. 5 0 0 10000000 2000000 600000 200000 0 2500000 No Ethanol 800000 10000 1000 100 10 0 10^- 10^- 10^- 10^- 10^- 10^6 5 4 3 2 1 Bacteria Concentration 1 100000 10000 1000 100 10 1 0 0.6 0.1 0.2 0.3 0.4 Mass [g] 0.5 0.6 0.7 0.8 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 Mass [g] 0.4 0.2 1 Luminescence No Ethanol 1000000 Luminescence 800000 Luminecence 1000000 Fig. 14 Bioluminescent Assay of the Nutrient Seed Medium (logarithmic) Fig 13. Bioluminescent Assay of the Nutrient Seed Medium (linear) 1200000 1200000 0. 5 Coupled Enzymatic Reaction: NADH:FMN-oxidoreductase NADH (NADPH) + H+ + FMN NAD(NADP)+ + FMNH2 (1) Luciferase FMNH2 + RCHO + O2 FMN + RCOOH + H2О + h (2) ’ The biological systems consisted of bioluminescent bacteria and their enzymatic extracts. Both test systems are based on the coupled enzymatic reaction shown above. 1400000 Luminescence This research developed two bioluminescent test systems for toxicity assays: the whole cell bacteria and the coupled enzyme system. 1. Farre M., Barcelo D. Toxicity Testing of waste water and sewage sludge by Biosensors, bioassays and chemical analysis. Trends in Analytical Chemistry, Vol. 22, No. 5, 2003. 2. Kratasyuk V.A. Esimbekova E.N. Polymeric Biomaterials, The PBM Series, V.1:Introduction to Polymeric Biomaterials, Arshady R Ed, Citus Books, London, pp. 301-343, 2003. 3. Kratasyuk V.A., et al. The use of bioluminescent bio-tests for study of Natural and laboratory aquatic ecosystems. Chemosphere, 42: 909915, 2001. 4. Kratasyuk V. A., et al. Bioluminescent water quality monitoring of salt lake Shira. Luminescence; 14: 193-195, 1999. 5. Paddle, Brian. Biosensors for Chemical and Biological agents of defense Interest. Review Article. Biosensors and Bioelectronics Vol. 11 No. 11:1079-113, 1996. 6. Vetrova E., Bioluminescence characteristics of Lake Shira water. Aquatic Ecology 36: 309-315, 2002. 10000000 1000000 2000000 References 100000000 Fig. 7 Bioluminescent Assessement of Growth Chamber Water Filtration 3000000 12 Buthenol Fig 12. Bioluminescent Assay of Butenol Gas on Coupled Enzyme System 4000000 Buthenol [µl] 200 Air Butanol gas was found to produce a slight inhibition of the enzymatic reaction (Fig. 12). Nutrient Water Bioluminescent Assessment 5000000 150 2000000 1800000 1600000 1400000 1200000 1000000 800000 600000 400000 200000 0 Gas [µl] Bioluminescent assessment of NanoCeram filters showed that the filters were capable of filtering bacteria (Fig. 6). 1000000 0 1000000 0 Filtered Bacteria Bacteria Concentration The bacterial system exposed to ethanol showed very pronounced reduction in light intensity (Fig.1). 1200000 200000 Bacteria 0 Fig. 2 Liquid Buthenol on E.coli Luminous Bacteria Fig 11. Bioluminescent Assay of Buthenol Gas on E.coli Bacteria System [Direct Injection ] 1600000 160000 • Bioluminescent methods were developed in this research to monitor the air, water, and soil samples in closed ecosystems. These methods serve as a set of guidelines for conducting bioluminescent toxicity tests for closed environments. • Bioluminescent tests were found to be capable of detecting toxins in the liquid solutions. • The bioluminescent systems were found to have high sensitivity to minute amounts of liquid ethanol (1µl) and butanol (2ul), which are common cleaners on space shuttles. • New bioluminescent methods for control of the purification of water were developed with NanoCeram filters. • The coupled enzyme system was slightly inhibited by an air sample of 500 ppm of buthanol gas. These investigations of bioluminescent assays indicate the advantages of using bioluminescence in applications for space biotechnology. This result will be used to develop a proposal entitled “Bioluminescent Biosensors for Space biotechnology”. The future prospects of this research is directed to the development of bioluminescent systems to control levels of contaminants in the air, water, and soil of closed ecological life support systems. In addition, bioluminescent methods for control of water filtration will be developed in collaboration with the Argonide Corporation. Bioluminescent Assessment of Gasses Gas samples (5000 ppm Butanol) were injected to the bioluminescent systems by two methods: (1) the gases were bubbled to 2 ml luminous bacteria solution (Fig. 10); (2) the gases were directly injected into the microplate (Fig. 11). Butanol was found to have a slightly excitatory effect on the bacteria. Fig. 10 Bioluminescent Assay of Buthenol Gas on E.coli Bacteria System [Injection into Vial ] Conclusions Future Work Soil Seed Medium: Bioluminescent Test of Seed Medium for Soil The seed medium fiber was cut into pieces, massed from 0.1 to 0.7 g, and soaked in 10 ml of dionized water overnight. 50 µl of E.coli bacteria was pipeted in concentrations from 1 to 10-5 into a microplate and the initial light intensity was measured. 20 µl seed medium solution was injected into the bacteria after 1-2 min and the new light intensity was recorded. PerkinElmer Bioluminometer This project aims to develop sensitive, low cost, versatile bioluminescent sensors capable of monitoring multiple aspects of the internal environment in closed ecological space life support systems. The objectives for this study were six fold: • to develop the biological component of bioluminescent sensors to monitor closed environment of space ecosystems. • to find the conditions (the amount of luminous bacteria and concentrations of enzymes, flavin mononucleotide FMN, tetradecanal aldehyde, NADH) to conduct environmental toxicity assays • to investigate the sensitivity of these bioluminescent test systems on model pollutants (ethanol and buthanol) • to investigate the nutrient water from environmental growth chambers and the process of its purification with NanoCeram filters • to develop the methods of gas pollutant detection • to develop assays for control of water filtration systems in environmental growth chambers Gass: Bioluminescent Assessment of Toxic Gasses Gas samples of 1000 ppm ethanol and 500 ppm buthanol were harnessed from the VOC project at the SLS lab. E.coli with LUX-gene dissolved in tryptic soy broth solution was prepared in concentrations from 1 to 10-5. Gas samples were directly injected into the microplate and indirectly injected in a sealed 2 ml vial. Light intensity I (t) was measured after definite time intervals for the duration of 1-2 min. The changes in light intensity I(0)/I(t)*100 % were correlated with toxicity of the air samples to biological organisms. Luminescence As NASA embarks on a new era of human space exploration, the environmental control of closed ecosystems will be crucial for the long-term success of missions into space since they maintain essential life support functions to sustain a human crew during space flight. It will be of crucial importance to develop biological sensors to monitor the environmental conditions inside closed ecosystems. The biological monitoring of the environmental constituents of closed ecological systems can be accomplished by bioluminescent detection. In the past, bioluminescent sensors have been developed to monitor natural aquatic ecosystems [1,2,4,5,6]. These methods were adapted to monitor systems used for human space travel. Liquid: Bioluminescent Assessment of a Water Filtration System The bioluminescent test system consisted of 100 µl E.coli bacteria in control in dilutions from 1 to 10-5of the bacterial solution. 80 ml of 1/3 Hoaglands water was collected from KSC growth chambers. Nutrient water was injected into the bioluminescent bacterial solutions on the microplate. Light intensity readings were taken with the bioluminometer to determine the steady state curve. A 5ml syringe with NanoCeram filters from Argonide Co. was used to filter the growth chamber water. Filtered water was pipeted on the microplate to see if bioluminescent test system can assess the filtration of water. Bacterial solution was filtered with NanoCeram and pipeted onto the microplate. The number of bacteria was calculated from their optical density at a 600 nm setting using a Genesis 20 spectrophotometer to be compared with light intensity readings from the bioluminometer. Bioluminescent Bacteria System To find the volume for maximum light intensity, E.coli bacteria dissolved in tryptic soy broth was pipeted in volumes from 10 to 140 µl into a microplate. The effect of different mediums [water and ethanol] was tested with different volumes of liquids from 0 to 100 µl. Coupled Enzyme Test System The enzymatic reaction mixture contained 10 µl 0.002% Aldehyde solution, 5 ul 0.04 mM FMN, 2-5 µl Luciferase-oxidoreductase (1 ml phosphate buffer added to vial of lyophilized enzymes), 20 µl phostphate buffer pH 6.9, 10 µl NADH. To determine effect of common toxins on the coupled ezyme system, buthanol was injected to the reaction mixture in concentrations from 0 to 10 µl. To determine the reaction mixture, 1 µl ethanol was injected into enzymatic reaction mixture with varying amounts of FMN and Aldehyde. Luminescence Bioluminescent Sensors for Space Biotechnology KSC Growth Chambers Luminescence Introduction Bioluminescent Test Systems Luminescence Bioluminescent assays were conducted to monitor the toxicity of contaminants in air, water, and soil samples taken from environmental chambers located at the Space Life Science Laboratory (SLSL) at Kennedy Space Center. Two methods were developed to monitor contaminants in closed ecological systems. They consisted of an in vivo assay using luminous bacteria, and an in vitro assay using the coupled enzyme system NADH:FMNoxidoreductase-luciferase. The bioluminescent assays were used to detect the contaminants in samples of water and gas. The luciferase enzyme system was found to have more sensitivity to ethanol than the bacteria system. Bioluminescent methods for the control of liquid filters were developed with luminous bacteria. Methods and Materials for Developing Bioluminescent Detection Systems Luminescence Abstract 0 0 10^-6 10^-5 10^-4 10^-3 10^-2 10^-1 1 Bacteria Concentration To determine if luminous bacteria could be used as an accurate measure of water filtration, the luminescence of the unfiltered bacteria (Fig. 9) was compared to their optical density (Fig. 8). The comparison showed that luminous bacteria test was highly sensitive. The nutrient soil solution has no toxic effect on the bioluminescent system. This proves to be good for using the bioluminescent system for toxicity testing. These results along with previous results also show that while our biosensor is sensitive to toxins like ethanol and butanol it is not affected by environmental materials like nutrient water or soil seed mediums. This research was conducted as a part of the 2005 Spaceflight and Life Sciences Training Program funded by the National Aeronautics and Space Administration. The authors recognize the support of the Dynamac Corporation, the NASA Spaceflight and Life Sciences Training Program Academic Partner Alliance and the United States Department of Agriculture. Thanks to Diane Shoeman, SIFT (Summer Industrial Fellowships for Teachers) and Frank Mycroft (SLSTP trainee) for conducting parallel laboratory research, Dr. Ignascio Eraso for providing samples of buthanol and ethanol, Dr. Micheal Roberts and Michelle Birmele for assistance with the PerkinElmer Victor 2 Bioluminometer, Lashelle E. McCoy for providing samples of 1/3 hoaglands solution from environmental growth chambers. In addition, we would like to thank SLSTP trainees, Antrelle Kid, Jake Elmer, Jonathan for providing laboratory materials essential for performing these experiments.