Team:Brown-Stanford/PowerCell/Introduction

Introduction

Mars is a hostile, desolate environment. In order to live there, humans will have to deal with extreme cold, unfiltered solar radiation, low oxygen, and little water¹. Cellular engineering will solve these problems in time, but that raises a new problem--the extra burden of providing these requirements raises the already considerable needs of these microbes². It may be possible to feed them from a stored cache of growth nutrients for some time, but these basic requirements will have to be extracted from local resources if a self-sustaining colony is to exist.

PowerCell is our solution to this problem; by engineering cyanobacteria to excrete sugar compounds photosynthesized from atmospheric carbon dioxide³, PowerCell will provide other bacterial cultures with a rich carbon source, a basic requirement for producing biomass and other compounds. In addition, PowerCell able to fix atmospheric N₂ and release it in a form accessible to bacteria, providing a basic requirement for protein synthesis and other crucial biological functions⁴.

By producing two of the macromolecules essential to bacterial growth, PowerCell will form a metabolic foundation for the biological systems which will eventually enable a settlement on Mars. Other microbes producing oxygen, heat, food, light, and other necessities will follow. In time, a complete biogenic life support system will be put together, all fueled by PowerCell.

We first provide an overview of the chassis organism we selected. Then, we consider some of the conditions on Mars which would affect how a photosynthetic bioreactor performs. Finally in our Nutrient Secretion section we describe our construct design, the work we accomplished in lab, and how we plan to use PowerCell to drive other processes on our Mars settlement.

Parts submitted to the Registry

Anabaena pSac vegetative-specific promoter: http://partsregistry.org/Part:BBa_K656010

CscB sucrose symporter from E. coli W: http://partsregistry.org/Part:BBa_K656011

Complete PowerCell construct: http://partsregistry.org/Part:BBa_K656012

References

¹ R. Hanel, B. Conrath, W. Hovis, V. Kunde, P. Lowman, W. Maguire, J. Pearl, J. Pirraglia, C. Prabhakara, B. Schlachman, G. Levin, P. Straat, T. Burke, Investigation of the Martian environment by infrared spectroscopy on Mariner 9, Icarus, Volume 17, Issue 2, October 1972, Pages 423-442, ISSN 0019-1035, DOI: 10.1016/0019-1035(72)90009-7. (http://www.sciencedirect.com/science/article/pii/0019103572900097)

² Weeks, Amy M, and Michelle C Y Chang. 2011. “Constructing de novo biosynthetic pathways for chemical synthesis inside living cells.” Biochemistry 50 (24) (June 21): 5404-5418. doi:10.1021/bi200416g.

³ Niederholtmeyer, Henrike, Bernd T Wolfstadter, David F Savage, Pamela A Silver, and Jeffrey C Way. 2010. “Engineering cyanobacteria to synthesize and export hydrophilic products.” Applied and Environmental Microbiology 76 (11) (June): 3462-3466. doi:10.1128/AEM.00202-10.

⁴ Chaurasia, Akhilesh Kumar, and Shree Kumar Apte. 2011. “Improved eco-friendly recombinant Anabaena sp. strain PCC7120 with enhanced nitrogen biofertilizer potential.” Applied and Environmental Microbiology 77 (2) (January): 395-399. doi:10.1128/AEM.01714-10.