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Genotypic and Phenotypic Responses of Candida albicans to Spaceflight (Micro-6)


Overview | Description | Applications | Operations | Results | Publications | Imagery

Experiment Overview

This content was provided by Sheila Nielson-Preiss, Ph.D, and is maintained in a database by the ISS Program Science Office.

Brief Summary

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)

  • Sheila Nielson-Preiss, Ph.D, Division of Health Sciences, Montana State University, Bozeman, MT, United States
  • Co-Investigator(s)/Collaborator(s)

    Information Pending


    University of Colorado at Boulder, BioServe Space Technologies, Boulder, CO, United States

    Sponsoring Space Agency

    National Aeronautics and Space Administration (NASA)

    Sponsoring Organization

    Human Exploration and Operations Mission Directorate (HEOMD)

    ISS Expedition Duration

    September 2012 - March 2013

    Expeditions Assigned


    Previous ISS Missions

    Increment 33/34 is the first planned mission for the Micro-6 investigation.

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    Experiment Description

    Research Overview

    • When cells are exposed to spaceflight they may acquire potentially harmful properties, including increased potential for infection and increased resistance to antimicrobial compounds. A greater understanding of the effects of space flight on potentially infectious organisms is critical.

    • The goal of the Genotypic and Phenotypic Responses of Candida albicans to Spaceflight (Micro-6) study is to understand the different responses and physical effects of reduced gravitational force on the yeast Candida albicans. Cells grown in microgravity are compared to cells grown in normal gravity. The team examines differences in gene expression, biofilm formation, and the susceptibility of the yeast to an antimicrobial agent.

    • Understanding the different responses and physical effects of microgravity on the yeast Candida albicans may provide new insights into better management and treatment of Candida infections when they occur.


    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.

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    Space Applications

    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.

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    Operational Requirements

    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.

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    Results/More Information

    Information Pending

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    Related Websites

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    image A Commercial Generic Bioprocessing Apparatus (CGBA) provides a controlled temperature environment for growth. The unit is pictured with 9 Group Activation Packs (GAP) that contain the C. albicans yeast.
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    image Fluid Processing Apparatus (FPA), in which are loaded growth media, the C. albicans microbial culture in stasis, and a termination reagent.
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    image Two Group Activation Packs (GAPs) each containing eight FPA Chambers.
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    image NASA Image: ISS033E011737 - Seven Group Activation Packs (GAP) inside of a Commercial Generic Bioprocessing Apparatus (CGBA). This CGBA was unpacked from the SpaceX Dragon vehicle, and is pictured on board the ISS Destiny Lab.
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    Information provided by the investigation team to the ISS Program Scientist's Office.
    If updates are needed to the summary please contact JSC-ISS-Program-Science-Group. For other general questions regarding space station research and technology, please feel free to call our help line at 281-244-6187 or e-mail at JSC-ISS-Payloads-Helpline.