Wednesday, January 16, 2013


Studies find hardy Earth microbes may resist conditions on Mars



 A hardy bacteria common on Earth was surprisingly adaptive to Mars-like low pressure, cold and carbon dioxide-rich atmosphere, a finding that has implications in the search for extraterrestrial life.

The bacteria, known as Serratia liquefaciens, is found in human skin, hair and lungs, as well as in fish, aquatic systems, plant leaves and roots.

"It's present in a wide range of medium-temperature ecological niches," microbiologist Andrew Schuerger, with the University of Florida, told Reuters.

Serratia liquefaciens most likely evolved at sea level, so it was surprising to find it could grow in an experiment chamber that reduced pressure down to a Mars-like 7 millibars, Schuerger said.

Sea-level atmospheric pressure on Earth is about 1,000 millibars or 1 bar.

"It was a really big surprise," Schuerger said. "We had no reason to believe it was going to be able to grow at 7 millibars. It was just included in the study because we had cultures easily on hand and these species have been recovered from spacecraft."

In addition to concerns that hitchhiking microbes could inadvertently contaminate Mars, the study opens the door to a wider variety of life forms with the potential to evolve indigenously.

To survive, however, the microbes would need to be shielded from the harsh ultraviolet radiation that continually blasts the surface of Mars, as well as have access to a source of water, organic carbon and nitrogen.

NASA's Curiosity Mars rover is five months into a planned two-year mission to look for chemistry and environmental conditions that could have supported and preserved microbial life.

Scientists do not expect to find life at the rover's landing site - a very dry, ancient impact basin called Gale Crater located near the Martian equator. They are however hoping to learn if the planet most like Earth in the solar system has or ever had the ingredients for life by chemically analyzing rocks and soil in layers of sediment rising from the crater's floor.

So far, efforts to find Earth microbes that could live in the harsh conditions of Mars have primarily focused on so-called extremophiles which are found only in extreme cold, dry or acidic environments on Earth.

Two extremophiles tested along with the Serratia liquefaciens and 23 other common microbes did not survive the experiment, which not only replicated Mars' low pressure, but also its cold temperature and carbon dioxide-rich atmosphere.

A follow-up experiment on about 10,000 other microbes retrieved from boring 40 to 70 feet into the Siberian permafrost found six species - all members of the genus Carnobacterium - that could survive and grow in the simulated Mars chamber, located at the Space Life Sciences Laboratory adjacent to NASA's Kennedy Space Center in Florida.

The next step is to see how the microbes fare under even more hostile conditions, such as higher salt levels, more radiation and less water.

Related studies to analyze the genetics and metabolism of the common bacteria Serratia liquefaciens also are under way.

"In the search for life on another planet, we have to start with something that we at least have access to. We don't have a Martian bacterium we can experiment with, not yet, so we keep trying to see if some of our own hardy micro-organisms have the ability to grow at another location," Schuerger said.

"If we can never find a microbe that can grow under conditions on another planet, then it starts implying that life may not exist on that other location," he said.

The studies appear in the December 19 edition of the Proceedings of the National Academy of Sciences and this week in the journal Astrobiology.

Industrial output rises in December but utilities slump




Industrial output rose in December and motor vehicle assembly picked up, suggesting the manufacturing sector continues to expand at a moderate pace.

Industrial production increased 0.3 percent last month after a 1.0 percent increase in November, the Federal Reserve said on Wednesday. The gain was in line with economists' expectations.

Manufacturing production increased 0.8 percent in December after advancing 1.3 percent the prior month. Automobile assembly increased from November's pace.

For the fourth quarter, industrial production rose at a 1.0 percent annual pace. Manufacturing output increased at a tepid 0.2 percent pace during the October-December period.

Factory activity has cooled in recent months and the industrial production report supported views that the sector, which carried the economy's recovery from the 2007-09 recession, was not heading for a hard landing.

Last month, mining production gained 0.6 percent after rising 0.3 percent in November. Utilities output slumped 4.8 percent as unseasonably warm weather held down demand for heating.

Last month, the amount of industrial capacity in use edged up to 78.8 percent from 78.7 percent in November.

Industrial capacity utilization - a measure of how fully firms are using their resources - was 1.5 percentage points below its long-run average.

Officials at the Fed tend to look at utilization measures as a signal of how much "slack" remains in the economy, and how much room growth has to run before it becomes inflationary.