NanoRacks-National Design Challenge-Centaurus High School-The Effects of Simulated Gravity on Bacterial Lag Phase in a Micro-Gravitational Environment (NanoRacks-NDC-CHS-Bacterial Lag Phase) - 02.22.17

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

ISS Science for Everyone

Science Objectives for Everyone
Bacteria are more virulent and grow more rapidly in space, but scientists are not sure why. NanoRacks-National Design Challenge-Centaurus High School-The Effects of Simulated Gravity on Bacterial Lag Phase in a Microgravity Environment (NanoRacks-NDC-CHS-Bacterial Lag Phase) studies the bacterial lag phase, a delay period before the start of exponential growth, which is much shorter in microgravity than it is on Earth. The experiment uses a centrifuge to simulate gravity, comparing microgravity and simulated-gravity Escherichia coli (E. coli) cultures to determine whether microgravity itself causes changes in bacterial growth.
Science Results for Everyone
Information Pending

The following content was provided by Brian Thomas, Teacher, and is maintained in a database by the ISS Program Science Office.
Experiment Details

OpNom: NanoRacks Module-55

Principal Investigator(s)
Centaurus High School , Centaurus High School, Lafayette, CO, United States

Co-Investigator(s)/Collaborator(s)
Brian Thomas, Teacher, Centaurus High School, Lafayette, CO, United States
Bryan McCarty, Centaurus High School, Lafayette, CO, United States
Abigail Schmid, Centaurus High School, Lafayette, CO, United States
Jack Carvalho, Centaurus High School, Lafayette, CO, United States

Developer(s)
Centaurus High School, Lafayette, CO, United States

Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)

Sponsoring Organization
National Laboratory Education (NLE)

Research Benefits
Space Exploration, Earth Benefits, Scientific Discovery

ISS Expedition Duration
March 2015 - September 2015; September 2016 - September 2017

Expeditions Assigned
43/44,49/50,51/52

Previous Missions
None

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Experiment Description

Research Overview

  • Bacterial lag phase is the least understood part of bacterial growth – why do bacteria wait before growing on Earth and why is that waiting period shorter in space? To fully understand the mechanisms behind bacterial lag phase, it is necessary to isolate gravity as the variable causing the change.
  • By using a centrifuge to simulate gravity aboard the International Space Station (ISS), NanoRacks-National Design Challenge-Centaurus High School-The Effects of Simulated Gravity on Bacterial Lag Phase in a Micro-Gravitational Environment (NanoRacks-NDC-CHS-Bacterial Lag Phase) determines whether or not gravity causes this change in bacterial lag phase. The growth of Escherichia coli (E. coli) is measured both in and out of a centrifuge aboard the ISS to ascertain if gravity is the causal variable.
  • Two potential results are expected from the research; either bacteria grows in the centrifuge as it would on Earth, or it grows in the centrifuge as it would in microgravity. If simulating gravity causes the bacteria to revert to Earth-length lag phase, a more complete knowledge of bacterial growth and how to control it is gained. If simulating gravity has no effect, efforts may be refocused towards how other factors (radiation, magnetism) influence the growth of bacteria, effects even more poorly understood than lag phase itself.

Description
NanoRacks-National Design Challenge-Centaurus High School-The Effects of Simulated Gravity on Bacterial Lag Phase in a Micro-Gravitational Environment (NanoRacks-NDC-CHS-Bacterial Lag Phase) seeks to determine whether bacterial lag phase is related to gravity. Previous studies in microgravity have shown that bacterial lag phase in space is drastically shorter than bacterial lag phase on Earth. Bacterial lag phase is the first part of the bacterial growth cycle where a colony isn't growing and is acclimating to the environment. A shorter lag phase can have serious negative implications for crew members due to the shorter time for exposure, contraction, incubation, and the display of symptoms. It is believed that (lack of) gravity is the factor that causes this change. To isolate gravity as the factor causing the change, the bacteria are grown in simulated gravity, via rotation in a centrifuge. If the recorded lag phase matches the lag phase of the ground based testing, it will prove that gravity is a variable impacting the change in lag phase. If it doesn't, gravity can be ruled out and other possible variables such as magnetism or radiation can be tested. This research allows for a better understanding of bacterial growth and gravity's effect upon it, helping humans better understand and control bacterial growth both in space and on Earth.

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Applications

Space Applications
Bacteria grow faster in space, but the reasons for this change are still unclear. This investigation helps scientists understand bacterial growth in a variety of gravitational environments, from simulated Earth gravity to microgravity. Understanding why bacteria grow differently in space improves efforts to prevent infections on future space missions. If experiments reveal that microgravity is not a cause of increased bacterial growth, scientists will study other possible causes such as magnetic fields and radiation.

Earth Applications
The lag phase is the earliest and the least understood stage of the bacterial growth cycle, but previous research has demonstrated it prepares bacteria for the eventual exponential growth. This investigation provides new information on how this phase works, including how external forces like gravity can affect it. Understanding the lag phase improves efforts to control bacterial growth on Earth, and could yield new findings about life in extreme environments, including the earliest forms of life on the planet. In addition, students at Centaurus High School in Lafayette, Colorado, proposed, designed and built the investigation, gaining unique experience in science, technology, engineering and math (STEM) to prepare them for future careers.

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Operations

Operational Requirements and Protocols

A total of 4 experiment inserts are changed out as part of this investigation. The first should be completed by 7 days after launch and the full experiment should be completed by 2 months after launch. All samples experiment inserts are returned ambient, soft stowage.

One Module is flown, with three additional experiment inserts. All hardware launches in passive cold stowage at -26°C. The Module is transferred to the NanoRacks Platform to start the powered operations phase. Following a minimum of 72 hours, power is removed from the Module and the end cap of the Module is removed. The first experiment is pulled out of the Module and the next experiment is installed. Following attachment of the end cap, power is restored and the next experiment commences. A total of four experiments are run. The Module and 3 experiments return to the ground at ambient temperatures in soft stowage.

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Decadal Survey Recommendations

Information Pending

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Results/More Information

Information Pending

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Related Websites



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Imagery

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Internal setup for the NanoRacks-National Design Challenge-Centaurus High School-The Effects of Simulated Gravity on Bacterial Lag Phase in a Micro-Gravitational Environment (NanoRacks-NDC-CHS-Bacterial Lag Phase) investigation.  Image courtesy of Jack Carvalho.

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NanoRacks-National Design Challenge-Centaurus High School-The Effects of Simulated Gravity on Bacterial Lag Phase in a Micro-Gravitational Environment (NanoRacks-NDC-CHS-Bacterial Lag Phase) NESI microcontroller and sensor housing.  Image courtesy of Jack Carvalho.

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Centrifuge setup with gears, walls, and vials for the NanoRacks-National Design Challenge-Centaurus High School-The Effects of Simulated Gravity on Bacterial Lag Phase in a Micro-Gravitational Environment (NanoRacks-NDC-CHS-Bacterial Lag Phase) investigation.  Image courtesy of Jack Carvalho.

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