Tag: microbes

Potentially dangerous bacteria found on ISS

9:24 am

Researchers have found five strains of bacteria on ISS that, while not dangerous now, has the potential to mutate into forms that could be a threat.

When Bezdan and colleagues ran the numbers on the space station microbes, however, they found that they were similar to only three – and rare ones, at that. They report similarities with strains found to date only once – one recovered from neonatal blood in a Tanzanian patient, another from a neonatal urine sample in the US, and the third from a 72-year-old woman with multiple health problems. In total, the researchers report, the eight strains thus “formed a unique ecotype”.

The ISS strains all contained genes associated with drug-resistance. They did not, however, contain combinations associated with high infection rates. Nevertheless, the results are enough for the researchers to sound a warning.

There are a lot of uncertainties here, including a lack of understanding of the effect of weighlessness on these bacteria. Nonetheless, this research highlights an important problem for future interplanetary spacecraft that has generally been ignored: Their small and limited ecology is very vulnerable to this kind of threat.

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Certain microbes survive in clean rooms by eating the cleaning fluids

10:51 pm

Researchers have found that the reason certain microbes seem to survive in all spacecraft clean rooms is that those microbes actually live off the very cleaning fluids used to scrub the rooms.

Despite extensive cleaning procedures, however, molecular genetic analyses show that the clean rooms harbor a diverse collection of microorganisms, or a spacecraft microbiome, that includes bacteria, archaea and fungi, explained Mogul. The Acinetobacter, a genus of bacteria, are among the dominant members of the spacecraft microbiome.

To figure out how the spacecraft microbiome survives in the cleanroom facilities, the research team analyzed several Acinetobacter strains that were originally isolated from the Mars Odyssey and Phoenix spacecraft facilities.

They found that under very nutrient-restricted conditions, most of the tested strains grew on and biodegraded the cleaning agents used during spacecraft assembly. The work showed that cultures grew on ethyl alcohol as a sole carbon source while displaying reasonable tolerances towards oxidative stress. This is important since oxidative stress is associated with desiccating and high radiation environments similar to Mars.

The tested strains were also able to biodegrade isopropyl alcohol and Kleenol 30, two other cleaning agents commonly used, with these products potentially serving as energy sources for the microbiome.

With this information, the space engineering community will be able to refine their clean room operations to eliminate these microbes so as to better sterilize spacecraft heading on life-seeking missions.

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Methane detected on Enceladus could come from microbes

8:38 am

The uncertainty of science: New research has found that the methane that Cassini detected being released from Enceladus’s interior could conceivably come from at least one Earth-type microbe.

Using various mixtures of gases held at a range of temperatures and pressures in enclosed chambers called “bioreactors,” Rittmann and his co-authors cultivated three microorganisms belonging to the oldest branch of Earth’s tree of life, known as Archaea. In particular, they focused on Archaean microbes that are also methanogens, which are able to live without oxygen and produce methane from that anaerobic metabolism. The team examined the simplest types of microbes, which could be the primary producers of methane at the base of a possibly more complex ecological food chain within the moon.

They tried to simulate the conditions that could exist within and around Enceladus’s hydrothermal vents, which are thought to resemble those found at a few deep-sea sites on Earth, often near volcanically active mid-oceanic ridges. According to their tests, only one candidate, the deep-sea microbe Methanothermococcus okinawensis, could grow there—even in the presence of compounds such as ammonia and carbon monoxide, which hinder the growth of other similar organisms.

There are a lot of fake news stories today trumpeting this result as proof that alien microbes can exist on Enceladus. The data does no such thing. All it shows that one methane producing microbe could possibly live in an environment that researchers guess might somewhat resemble the situation on Enceladus. However, as the article admits,

Scientists do not really know the precise conditions on Enceladus yet, of course. And in any case it is possible any life there, if it exists, is nothing like any DNA-based organism on our planet, rendering our Earth-based extrapolations moot. What’s more, these findings only show microbial life might exist in one particular subset of possible environments within the moon’s dark ocean.

This result is interesting, but it really proves nothing about Enceladus itself.

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Scientists have found microbes inside a lava tube that can thrive in the freezing cold and low oxygen environment of Mars.

9:40 pm

Scientists have found microbes inside a lava tube that can thrive in the freezing cold and low oxygen environment of Mars.

In a laboratory setting at room temperature and with normal oxygen levels, the scientists demonstrated that the microbes can consume organic material (sugar). But when the researchers removed the organic material, reduced the temperature to near-freezing, and lowered the oxygen levels, the microbes began to use the iron within olivine – a common silicate material found in volcanic rocks on Earth and on Mars – as its energy source.

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