The Genotypic and Phenotypic Responses of Candida albicans to Spaceflight (Micro-6) experiment studies how microgravity affects the health risk posed by the opportunistic yeast Candida albicans.Principal Investigator(s)
University of Colorado at Boulder, BioServe Space Technologies, Boulder, CO, United States
National Aeronautics and Space Administration (NASA)Sponsoring Organization
Human Exploration and Operations Mission Directorate (HEOMD)ISS Expedition Duration
September 2012 - March 2013
33/34Previous ISS Missions
Increment 33/34 is the first planned mission for the Micro-6 investigation.
Previous studies indicate that both Candida albicans (C. albicans) and Saccharomyces cerevisiae (types of yeast) respond to low-shear (low-stress) modeled microgravity (LSMMG) with gene expression changes and morphological (structural) consequences. Gene expression is the conversion of information from a gene to a functional product that the gives rise to structural and observable changes in the organism. The goal of the Genotypic and Phenotypic Responses of Candida albicans to Spaceflight (Micro-6) study is to further examine the responses of C. albicans to microgravity by performing hypothesis-driven studies in space flight conditions. The overriding hypothesis of this study is that exposure of C. albicans to microgravity alters gene expression and morphology, consistent with a potential increase in virulence. These studies endeavor to 1) inform the value of LSMMG for predicting the physiological responses of C. albicans, 2) further explore and document the phenotypic (observable characteristic) parameters of C. albicans that are associated with pathogenicity (ability to produce infectious disease) and altered during exposure to spaceflight, and 3) predict conserved responses of higher eukaryotes (cells with a nucleus), including humans, to space flight conditions.
The Micro-6 experiment makes use of BioServe's flight certified hardware: Group Activation Packs (GAPs) stored in a Commercial Generic Bioprocessing Apparatus (CGBA). The CGBA is an incubator capable of controlling the temperature between 8ºC and 37ºC and can hold up to 16 GAPs. Each GAP holds eight Fluid Processing Apparatus (FPA) inserts. The FPA is composed of a glass barrel divided into three chambers that are separated from one another by rubber septa. Each FPA contains growth medium in the first chamber, a microbial culture suspended in stasis medium in the second chamber, and a termination reagent in the last chamber.
The fundamental space biology experiments address basic questions of how life responds to gravity and space environments.Earth Applications
The experiments probe the fundamental nature of life in order to enhance our understanding of how life responds to physical phenomena and physical forces on Earth and serve as the basic biological foundation in support of exploration.
Late Load L-28 hours, Early Recovery R+6 hours.Operational Protocols
The samples will be flown up on SpaceX-1 at ambient temperature. Shortly after the GAPs have been de-stowed from the Dragon spacecraft, a crewmember will stow the GAPs in a CGBA. The CGBA will be set to the growth temperature of 30°C and then the crewmember will attach the crank to the top of the early set of GAPs and turn it to activate growth of the C. albicans. After 26 or 32 hours, depending on the sample, the crewmember will terminate the GAPs by again inserting the crank on the top of the GAP and turning. The terminated GAPs will be stored in a separate CGBA set to 4°C. Late in the Dragon docking period, a crewmember will use the crank to activate the late set of GAPs. The activated GAPs will be placed in the CGBA set to 30°C. After 26 or 32 hours, depending on the sample, a crewmember will use the crank to terminate the GAPs. The terminated GAPs will be stored in the CGBA set to 4°C. All GAPs will be stowed in Dragon spacecraft for descent and processing at the PIs labs.