OpNom: Micro-xxExperiment Overview
The Gravitational Effects on Biofilm Formation During Space Flight (Micro-2) experiment studies how gravity alters biofilm (aggregation of microorganisms) formation with the goal of developing new strategies to reduce their impact on crew health and to minimize the harmful effects of biofilms on materials in space and on Earth.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
March 2010 - September 2010
23/24Previous ISS Missions
This will be the first flight for the Micro-2 experiment.
The goal of the Gravitational Effects on Biofilm Formation During Space Flight (Micro-2) experiment is to understand the effects of microgravity on the growth, cellular physiology, and cell-cell interactions in microbial biofilms (aggregation of microorganisms). It will focus on two model microorganisms that form biofilms both inside and outside of the human body, Pseudomonas aeruginosa and Staphylococcus aureus. These microbes can switch between benign and pathogenic interactions with humans and may be relevant to crew health during extended missions. This experiment will also test the ability of novel antimicrobial surfaces to reduce biofilm formation.
When cells form biofilms they have a number of potentially harmful properties, including increased potential for infection and increased resistance to antimicrobial compounds. Biofilms have the potential to cause significant damage to both spacecraft and their crew; numerous problems caused by biofilms were documented on Mir. A greater understanding of the effects of spaceflight on biofilms is critical.
The Micro-2 experiment will make use of Group Activation Packs (GAPs) stored in a Commercial Generic Bioprocessing Apparatus (CGBA). The CGBA is a flight certified 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 will contain growth medium with membranes in the first chamber, a microbial culture suspended in stasis medium in the second chamber, and a termination reagent in the last chamber.
Understanding the different effects of microgravity on biofilm formation may provide new insights into combating biofilm formation in space and may lead to better management and treatment of infections if they occur. Also, novel antimicrobial surfaces will be tested for their potential to reduce the impact of biofilms in future spacecraft design.Earth Applications
According to the Center for Disease Control (CDC), hospital-acquired infections are the fourth leading cause of death in the United States behind stroke, cancer and heart disease. Furthermore, it is estimated that >65% of all bacterial infections are associated with biofilms. A greater understanding of biofilms is essential if we are to find effective methods to combat their formation. Furthermore, the low-shear conditions microbes experience in microgravity are similar to those found in the human body that are difficult to study. This work may provide new insights into the role of shear and other physical effects, such as convection, on biofilm formation.
The Micro-2 experiment consists of 128 samples housed in 16 GAPs. The temperature profile of the CGBA and the two temperature loggers (HOBOs) are required for the post-flight analysis of the data.Operational Protocols
The samples will be stowed in the CGBA at 8ºC until as late in the mission as possible then CGBA temperature will be set to 37ºC. After 14-21 hours, to allow the temperature of the samples in the FPAs to have reached and stabilized at 37ºC, all 16 GAPs will be activated. To activate the samples, a crewmember must remove the CGBA from its middeck stowage location, take out each GAP and install the hand crank. The hand crank is then turned until the cell suspension in the second chamber is introduced to the growth media in the first chamber. Following the 72-hour growth period, a crewmember will again install the hand crank and terminate the GAPs by adding the termination reagent in the last chamber to the cells. Only GAPs 1-10 will need to be terminated. All GAPs will be returned to the CGBA and the CGBA will be set to 8ºC where it will remain until recovery.