NanoRacks-Valley Christian High School-The Effect of Microgravity on Probiotic Growth (NanoRacks-VCHS-Probiotic Growth) - 12.06.17

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

ISS Science for Everyone

Science Objectives for Everyone
NanoRacks-Valley Christian High School-The Effect of Microgravity on Probiotic Growth (NanoRacks-VCHS-Probiotic Growth) investigates how well commercial probiotic bacteria grow in the microgravity environment of space. The experiment consists of an automated setup that monitors bacterial growth in a fluid medium using cameras, lights and a special light-sensitive protein that helps track bacterial abundance. NanoRacks-VCHS-Probiotic Growth runs for thirty days aboard the International Space Station and enlists the help of high school science classes back on Earth in preparation steps, data analysis and interpretation.
Science Results for Everyone
Information Pending

The following content was provided by Valley Christian High School, and is maintained in a database by the ISS Program Science Office.
Experiment Details


Principal Investigator(s)
Valley Christian High School , Valley Christian High School, San Jose, CA, United States

Dan Saldana, Valley Christian High School, San Jose, CA, United States

Valley Christian High School , San Jose , CA, United States
NanoRacks, LLC, Webster, TX, United States

Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)

Sponsoring Organization
National Laboratory Education (NLE)

Research Benefits
Information Pending

ISS Expedition Duration
April 2017 - September 2017

Expeditions Assigned

Previous Missions
Information Pending

^ back to top

Experiment Description

Research Overview

  • NanoRacks-Valley Christian High School-The Effect of Microgravity on Probiotic Growth (NanoRacks-VCHS-Probiotic Growth) determines how biological pathways related to bacterial growth in Lactobacillus casei (L. casei) are affected by microgravity.
  • NanoRacks-VCHS-Probiotic Growth measures the growth of L. casei by calculating the amount of light that is able to pass through the mass of cells.
  • NanoRacks-VCHS-Probiotic Growth determines if there are any major effects on biological pathways due to the change in gravity.
  • Additionally, the changes of probiotic growth in microgravity can affect the digestion of astronauts.


Probiotics are live microorganisms both produced by and ingested by humans. The informal terminology for probiotics is “good bacteria”. This name has been assigned to probiotics, as they aid in the performance of bodily processes, such as the digestion of food and destruction of disease-causing microorganisms. Astronauts in space may be affected by the effect of microgravity conditions on probiotics. If so, this would affect their gastrointestinal tract and digestive system. To explore the effects of microgravity on probiotics, NanoRacks-Valley Christian High School-The Effect of Microgravity on Probiotic Growth (NanoRacks-VCHS-Probiotic Growth) raises a probiotic culture in space for thirty days. The bacteria used is Lactobacillus casei (L. casei), found in the human intestine and mouth. L. casei is beneficial bacteria that lowers the pH in the digestive system through the production of lactic acid. This increase in acidity impedes the growth of harmful bacteria detrimental to human health. The bacteria are lyophilized to ensure that they remain alive when they reach the International Space Station. An expandable chamber is utilized to remove all excess air. Periodic pumping of broth occurs to remove old broth and introduce new broth. To monitor the growth of the probiotics, green fluorescent proteins are inserted in the bacterial culture before lyophilization. To monitor the bacteria, a pair of photos is taken every six hours. The first image is with a white light-emitting diode (LED) so the Microlab can be monitored. The second image is with an ultraviolet LED so the rate of bacterial growth via the green fluorescent protein (GFP) can be observed. Additionally, at three hour intervals the white LED turns on and a light sensor records the quantity of light that passes through the chamber. These light sensor measurements provide quantitative measurements of the bacterial growth. For example, a small amount of light passing through implies a large quantity of bacteria because the presence of bacteria reduce the quantity of light detected. These periodic measurements occur throughout the thirty day period. Analysis of the photos and the light sensor measurements allow for the formulation of a conclusion regarding the effects of microgravity on probiotics.

^ back to top


Space Applications
NanoRacks-VCHS-Probiotic Growth determines how well probiotic microbial communities develop in space. Results demonstrate how certain dietary supplements can support astronaut health during long-term space missions. Deeper knowledge of microbial biology can also contribute to the development of food cultivation strategies in space.

Earth Applications
NanoRacks-VCHS-Probiotic Growth expands understanding of how unique and commercially significant microbial communities operate under unusual conditions. This research also contributes to science, technology, engineering, and math (STEM) education goals by including high-school student participation. These students receive training in scientific methods, teamwork and product testing.

^ back to top


Operational Requirements and Protocols
NanoRacks Black Box is completely autonomous and only requires installation and removal. During actual operation, photographic data is sent to the investigators to track the progress of the experiment. The first three days have the most data transmitted (about 16 VGA quality photographs along with environmental data (humidity and temperature). Thereafter, transmission is limited to 1 VGA photo and environmental data per day for the duration of the flight. The payload chamber needs to be returned to the researchers so its contents can be examined under an atomic force microscope.

^ back to top

Decadal Survey Recommendations

Information Pending

^ back to top

Results/More Information

Information Pending

^ back to top

Related Websites

^ back to top