MICROBIAL DYNAMICS IN INTERNATIONAL SPACE STATION (MICROBE-I/II), TWO INVESTIGATIONS
Research Area: Microbiology
Expedition(s): 19, 20 and 23- 26
Principle Investigator(s): ● Koichi Makimura, MD, PhD, Teikyo University, Tokyo, Japan
● Masao Nasu, PhD, Osaka University, Osaka, Japan
RESEARCH OBJECTIVES
The Microbe investigations are a set of activities used to monitor the abundance and diversity
of fungi and bacteria in Kibo (the Japanese Experiment Module) of the International Space
Station (ISS).
EARTH BENEFITS
This experiment contributes to the
establishment of a standard microbial
sampling method that pharmaceutical and
food industries can use. These industries
require strict microbial control and could
greatly benefit from such techniques.
Microbe can also contribute to a better
microbial quality control of freshwater, a
fundamental part of daily life.
SPACE BENEFITS
Periodically monitoring microbial activity in
the JEM module secures microbial hygiene
and can be used in other closed habitat
systems, such as the relatively constant
environment of space ships.
RESULTS
FUNGAL POPULATIONS (MAKIMURA)
Samples were collected from 3 sites in Kibo (air diffuser, handrail, and surfaces) for analysis of
fungal biota approximately 1 year after the module had docked to the ISS. Samples taken from
Kibo before launch and from our laboratory were used as controls. In the case of Kibo, both
microbe detection sheet (MDS) and swab culture tests of orbital samples were negative. The
MDS were also examined by field emission-scanning electron microscopy; no microbial
structures were detected. However, fungal DNAs were detected by real-time PCR and analyzed
by the clone library method; Alternaria and Malassezia spp. were the dominant species before
launch and in space, respectively. The dominant species found in specimens from the air
conditioner diffuser, lab bench, door push panel, and facility surfaces on the laboratory (ground
controls) were Inonotus, Cladosporium, Malassezia, and Pezicula, respectively. The fungi in Kibo
were probably derived from contamination due to humans, while those in the laboratory came
from the environment (eg, the soil). In conclusion, the cleanliness of Kibo was equivalent to that
in a clean room environment on the ground.
ISS033E012541 – Japan Aerospace Exploration Agency
(JAXA) astronaut Akihiko Hoshide, Expedition 33 flight
engineer, performs microbial white tube sampling in the
JEM Pressurized Module with wet wipes and sampling
sheets for the JAXA MICB (Microbe-III) experiment. JAXA
image.