Tag Archives: bacteria

The lone survivor: single organism ecosystem discovered

Scientists has discovered a new bacterial organism called desulforudis audaxviator that is an entirely self-sufficient ecosystem in and of itself, 2.8 km below the Earth’s surface the desulforudis audaxviator’s genome contains:

everything needed for the organism to sustain an independent existence and reproduce, including the ability to incorporate the elements necessary for life from inorganic sources, move freely, and protect itself from viruses, harsh conditions, and nutrient-poor periods by becoming a spore.

This is a beautiful discovery, and a testament to the diversity and splendour of Life. Also, it suggests there is no theoretical reason why life cannot survive in similar conditions on other planets:

“One question that has arisen when considering the capacity of other planets to support life is whether organisms can exist independently, without access even to the sun,” says Chivian. “The answer is yes, and here’s the proof. It’s sort of philosophically exciting to know that everything necessary for life can be packed into a single genome.

[image from eschipul on flickr]

Conducting bacteria that feed off garbage to produce power

Is rubbish going to become too valuable to be piled up like this?Whilst some of first generation biofuels like corn and soy based ethanol are proving to be more trouble than their worth, scientists are working hard on second and third generation alternatives that should add to our energy mix without damaging our food supply. One new development is microbial fuel cells (MFCs) – bacteria that breaks down garbage and conducts electricity. Scientists think by digesting our waste these cells could replace up to 25% of the fuels we currently use.

In a microbial fuel cell, the bacteria acts on the anode of the circuit, breaking down waste with oxidation. As a byproduct they produce electrons. Normally a bacteria would transfer these electrons to a nearby oxygen molecule but if the fuel cell has no oxygen in it, the microbe must move these electrons elsewhere and an MFC uses this to drive an electrical current.

Researchers are beginning to make headway in creating self-contained microbial fuel cells. Biofilms are bacteria that create matrices of material to attach themselves to the anode. This mix of sugars, proteins and cells is thought to contain tiny conducting nanowires that help move the electrons into the electrical circuit, making the whole clump of bacteria act like a big living anode. If this works, people aren’t going to be leaving their litter on the streets any longer. It’ll be too valuable!

[via Daily Galaxy, picture by Alan Stanton]

Oil You Can Eat: Bacteria Eat Rubbish, Egest Petrol

Splendid news from Silicon Valley: a flotilla of companies, including one called LS9, are now starting toblack_gold genetically engineer bacteria that poop petrol and eat any old rubbish:

Because crude oil (which can be refined into other products, such as petroleum or jet fuel) is only a few molecular stages removed from the fatty acids normally excreted by yeast or E. coli during fermentation, it does not take much fiddling to get the desired result.

For fermentation to take place you need raw material, or feedstock, as it is known in the biofuels industry. Anything will do as long as it can be broken down into sugars, with the byproduct ideally burnt to produce electricity to run the plant.

The key facts are that this is a carbon-neutral method of producing conventional crude oil (and all the good stuff you can get out of crude oil), that doesn’t cause food inflation, consumes waste biomass, and doesn’t require us to spend $billions upgrading our current transport infrastructure to compatibility with hydrogen fuel cells.

The company is not interested in using corn as feedstock, given the much-publicised problems created by using food crops for fuel, such as the tortilla inflation that recently caused food riots in Mexico City. Instead, different types of agricultural waste will be used according to whatever makes sense for the local climate and economy: wheat straw in California, for example, or woodchips in the South.

The main onion in the ointment seems to be the scale required to produce the amount of oil needed:green_oil

However, to substitute America’s weekly oil consumption of 143 million barrels, you would need a facility that covered about 205 square miles, an area roughly the size of Chicago.

This is it: with oil prices continuing to break records and global warming coming around the corner this is the direction we need to go in (unless there’s some other huge problem with it, aside from the Chicago-sized thing?).

[story at Times Online, via Charlie’s Diary][images by nalilo and XcBiker]

Evolution observed in laboratory bacteria

Image of E Coli in the labFor the first time, a major evolutionary change has been observed in laboratory conditions, giving even greater weighting to evolutionary theory. The bacteria used, a strain of E. Coli, was first introduced into the Michigan State University lab twenty years ago by evolutionary biologist Richard Lenski. Some 44,000 generations later, the bacteria are still reproducing.

Somewhere around the 31,500th generation, the E. Coli developed a trait not present in the original strain: they began to be able to metabolise citrate, the inability of which is one of the main ways scientists distinguish E. Coli from other bacteria. Importantly, the paper says that evolution occurs as a sum of the previous steps of mutation and that as this history varies between groups of creatures, evolution is a random and unpredictable act.

“It’s the most profound change we have seen during the experiment. This was clearly something quite different for them, and it’s outside what was normally considered the bounds of E. coli as a species, which makes it especially interesting,” says Lenski.

One of the main criticisms of evolutionary theory has been that it is a theory that hasn’t been observed in the real world. Creationists are going to have a hard time explaining this result away, one suspects.

[via Daily Kos, image by scaliber001]