Nav: Home

Why bacteria survive in space -- UH biologists discover clues

June 27, 2018

In professor George Fox's lab at the University of Houston, scientists are studying Earth germs that could be contaminating other planets. Despite extreme decontamination efforts, bacterial spores from Earth still manage to find their way into outer space aboard spacecraft. Fox and his team are examining how and why some spores elude decontamination. Their research is published in BMC Microbiology.

To gain access into the uber-sanitized clean rooms at NASA's Goddard Space Flight Center in Greenbelt, Maryland, the world's largest clean room, or the Jet Propulsion Laboratory in Caltech, California, employees pass through a series of lobbies. One, with adhesive floor mats, traps dirt carried on shoes. Another, about the size of an old phone booth, delivers a forced-air shower where dozens of air jets blow away dirt and debris. Only after these sterilization measures can they don the bodysuits, head covers and other disinfected regalia.

And still, bacteria survive and have been carried onboard the International Space Station and found on the Mars Rover. The ability of bacteria to survive extreme conditions could potentially lead to a process called 'forward contamination.'

"The search for life elsewhere is impacted by the possible transport of organisms from Earth to solar system bodies of interest," said Fox, Moores Professor of Biology and Biochemistry and Chemical and Biomolecular Engineering at UH. Fox is no stranger to microbiology. In the 1970's, along with fellow scientist Carl Woese, he revolutionized the field by discovering that archaea are a separate domain of life.

As with natural selection, the cleaning process inside clean rooms will eventually kill off the weaker bacteria while a stronger strain adapts and is unphased by the cleansers.

"No matter what we do, some bacterial spores appear to be finding ways to escape decontamination," said Madhan Tirumalai, a post-doctoral biologist in Fox's lab. "I'm trying to understand what makes these spores so special at their genomic level and relate these features with their ability to evade decontamination measures."

It starts with sequencing

The Fox team studied non-pathogenic (non-disease-causing) bacteria that belong to the genus Bacillus and produce highly resistant spores. They were isolated from cleanrooms and spacecraft assembly facilities at the Jet Propulsion Laboratory.

They sequenced the complete genome of two strains resistant to peroxide and radiation: B. safensis FO-36bT and B. pumilus SAFR-032. Then they compared the genomes of those strains and that of another strain, B. safensis JPL-MERTA-8-2, with bacteria known to produce spores that are vulnerable to peroxide and radiation, such as the strain B. pumilus ATCC7061T. The B. safensis JPL-MERTA-8-2 strain was isolated from the Mars Odyssey Spacecraft and associated facilities at the Jet Propulsion Laboratory and later also found on the Mars Explorer Rover (MER) before its launch in 2004.

"The genome blueprint gave us the basic clues of what the organism might be harboring," said Tirumalai. By comparing the blueprints of the four strains, they found 10 genes that are unique to the FO-36b, that are not found in any other organisms (including other Bacillus strains). That is 10 genes whose functions are unknown - or 10 suspects for why spores of B. safensis FO-36bT are resistant to peroxide and radiation, although it is not immediately obvious that the presence or absence of any specific gene or combination of genes is responsible for the variations in resistance seen.

"It is quite possible that distinctions in gene regulation can alter the expression levels of key proteins thereby changing the organism's resistance properties without gain or loss of a particular gene. These are potential genes of interest with respect to the resistance of the spores of this strain" said Tirumalai.

As it turns out, four of these genes are found on phage elements of the bacterial strain. Phage, short for bacteriophage, is a virus that infects bacteria. Phages are major facilitators for transferring genes between microbes.
-end-
"The task to eliminate microbes in clean rooms, where spacecraft are assembled, or aboard spacecraft, will continue to be a challenge for NASA and other space agencies," said Tirumalai.

About the University of Houston

The University of Houston is a Carnegie-designated Tier One public research university recognized with a Phi Beta Kappa chapter for excellence in undergraduate education. UH serves the globally competitive Houston and Gulf Coast Region by providing world-class faculty, experiential learning and strategic industry partnerships. Located in the nation's fourth-largest city and one of the most ethnically and culturally diverse regions in the country, UH is a federally designated Hispanic- and Asian-American-Serving institution with enrollment of more than 45,000 students.

University of Houston

Related Bacteria Articles:

Conducting shell for bacteria
Under anaerobic conditions, certain bacteria can produce electricity. This behavior can be exploited in microbial fuel cells, with a special focus on wastewater treatment schemes.
Controlling bacteria's necessary evil
Until now, scientists have only had a murky understanding of how these relationships arise.
Bacteria take a deadly risk to survive
Bacteria need mutations -- changes in their DNA code -- to survive under difficult circumstances.
How bacteria hunt other bacteria
A bacterial species that hunts other bacteria has attracted interest as a potential antibiotic, but exactly how this predator tracks down its prey has not been clear.
Chlamydia: How bacteria take over control
To survive in human cells, chlamydiae have a lot of tricks in store.
Stress may protect -- at least in bacteria
Antibiotics harm bacteria and stress them. Trimethoprim, an antibiotic, inhibits the growth of the bacterium Escherichia coli and induces a stress response.
'Pulling' bacteria out of blood
Magnets instead of antibiotics could provide a possible new treatment method for blood infection.
New findings detail how beneficial bacteria in the nose suppress pathogenic bacteria
Staphylococcus aureus is a common colonizer of the human body.
Understanding your bacteria
New insight into bacterial cell division could lead to advancements in the fight against harmful bacteria.
Bacteria are individualists
Cells respond differently to lack of nutrients.

Related Bacteria Reading:

Bacteria: Staph, Strep, Clostridium, and Other Bacteria (Class of Their Own (Paperback))
by Judy Wearing (Author)

The Bacteria Book: The Big World of Really Tiny Microbes
by Steve Mould (Author)

I Contain Multitudes: The Microbes Within Us and a Grander View of Life
by Ed Yong (Author)

Bacteria: A Very Short Introduction (Very Short Introductions)
by Sebastian G.B. Amyes (Author)

A Field Guide to Bacteria (Comstock Book)
by Betsey Dexter Dyer (Author)

From Bacteria to Bach and Back: The Evolution of Minds
by Daniel C. Dennett (Author)

BACTERIA: An Educational FunBook for Kids (and Adults) (Educational Books for Children Series)
by Alexander Matis Msc (Author)

Bacteria: The Benign, the Bad, and the Beautiful
by Trudy M. Wassenaar (Author)

Molecular Genetics of Bacteria, 4th Edition
by Larry Snyder (Author), Joseph E. Peters (Author), Tina M. Henkin (Author), Wendy Champness (Author)

Premed Kids: Microbiology - Bacteria & Viruses
by April Chloe Terrazas (Author)

Best Science Podcasts 2018

We have hand picked the best science podcasts for 2018. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Why We Hate
From bullying to hate crimes, cruelty is all around us. So what makes us hate? And is it learned or innate? This hour, TED speakers explore the causes and consequences of hate — and how we can fight it. Guests include reformed white nationalist Christian Picciolini, CNN commentator Sally Kohn, podcast host Dylan Marron, and writer Anand Giridharadas.
Now Playing: Science for the People

#482 Body Builders
This week we explore how science and technology can help us walk when we've lost our legs, see when we've gone blind, explore unfriendly environments, and maybe even make our bodies better, stronger, and faster than ever before. We speak to Adam Piore, author of the book "The Body Builders: Inside the Science of the Engineered Human", about the increasingly amazing ways bioengineering is being used to reverse engineer, rebuild, and augment human beings. And we speak with Ken Thomas, spacesuit engineer and author of the book "The Journey to Moonwalking: The People That Enabled Footprints on the Moon" about...