Making Soil in Space

While doing more research into space mining, in this case thinking about refining carbonaceous chondrites I wondered if it would make more sense, at least for long term planning, to use lichen to naturally refine the water and organic molecules found in carbonaceous minerals.

The general idea is relatively simple, after finding a sufficiently large deposit of carbonaceous chondrites, either on an asteroid or a planet's moon, a balloon greenhouse is built around the mineral deposit (or the minerals are deposited inside the balloon greenhouse).  When the balloon structure is ready to be sealed off an initial feed stock of atmospheric gases and lichen colonies are added.  As time wears on the lichen will naturally break down the rock formations liberating oxygen, amino acids, carbon, and other chemicals essential for life.  The greenhouse balloon would first be ready for the gentle introduction to limited insect populations that would aid in increasing the complexity of the frontier bio-sphere.  Many years after the greenhouse was inflated, plants capable of surviving in a micro-gravity environment could join the frontier species.  Eventually the balloon would be ready to become a fully fledged complex ecosystem, either continuing on as a micro-gravity population or it could be attached to a spinning structure to allow for more terrestrial plants and animals to grow.

The rational behind choosing lichen as the colony organism stems from research done by the European Space Agency where lichen colonies were exposed to the extremes of space several times for a total of 14.6 days.  When the colonies were returned to terra-firma researchers determined they had passed the hell test with flying colors, zero fatalities and zero colony loss.  In the event that a greenhouse balloon is punctured by a micro-meteorite the loss of the contained air would not mean the end of the lichen colony.

July 15:  I should follow up with some more technical bits about temperature regulation.  On the plus side the usual 10 minutes of research seems to indicate that this idea is kind of fresh.  There is also the question, why do this soil making approach versus hydroponics?  I have no good answer, this just seemed really cool
July 15 (30 min later):  I managed to find one reference to using microbes for making refined products from lunar soil (found here)  Cyanobacteria harvested from Yellowstone's hot springs appeared to do an excellent job at breaking down lunar regolith into more useful chemical forms.  What is confusing to me is that the article talks about how the bacteria only need 3 things, (in addition to the regolith) air, water, and light, while these substances are extremely easy to find on Earth, neither water nor air are as easy to find in space, it makes me wonder about where in the colonization timeline this would make sense.  Personally I'm still pro-lichen, those little guys self regulate water needs.

I need to put less effort into proving other people have already thought of these things
http://www.cell.com/trends/microbiology//retrieve/pii/S0966842X10000430?cc=y#MainText
 http://www.sciencedirect.com/science/article/pii/S0032063397000172