From: roberts@cmr.ncsl.nist.gov (John Roberts)
Subject: Re: Energy production on Earth
X-Added: Forwarded by Space Digest
Organization: National Institute of Standards and Technology formerly National Bureau of Standards
Original-Sender: isu@VACATION.VENARI.CS.CMU.EDU
Distribution: sci
Date: Tue, 5 Jan 1993 00:17:57 GMT


-From: Ligon@macgw1.ge.com (Woody Ligon)
-Subject: Re: Energy production on Earth
-Date: 4 Jan 93 19:30:26 GMT
-Organization: GE-CRD

-In article <C0C251.Cxz.1@cs.cmu.edu>, roberts@cmr.ncsl.nist.gov (John
-Roberts) wrote:
-> A report on the radio this morning described a genetically engineered
-> bacterium, in which two genes were spliced in to allow it to do a very
-> good job of converting complex carbohydrates (including celluose) into
-> ethanol. Evidently the project is far enough along that there are plans
-> to build a plant in New York, to produce 15(?) million gallons of ethanol
-> per year from paper mill sludge.
-> 
-> Now, let's hope the bacterium doesn't get loose in the environment, or 
-> that it requires something to live that's found only in the culture tanks. :-)

-Well yes I guess that could be a problem, but if most attempts to grow
-microorganisms in "megaculture" offer any lessons then just the opposite is
-more likely.

One method that's been proposed to reduce the risk of genetically modified
microorganisms getting out and causing trouble is to use as a base stock some
tailored or selected organism that in order to live requires trace amounts
of some organic nutrient that's cheap to produce but which isn't found in
nature. I don't know to what extent this has actually been implemented.
Bacteria sometimes exchange genetic information, so it requires some
cleverness to come up with a nutrient requirement that's very unlikely to
be circumvented by a simple genetic swap with a wild microorganism.

-Usually what happens is that the cultures become contaminated with
-something far more competitive than the "special bug"  and the special bug
-just gets killed off by the competition.  Alternatively the special bug may
-grow competitively only under very narrowly defined conditions. Such
-conditions are quite hard to maintain with a heterogenous feedstock like
-forest products.  Also variables as simple as temperature control are not
-always easy to maintain between for example--winter and summer.  I would
-like to hear comments from the people who make antibiotics by fermentation
-on the probability of success here. 

Also relevant - bacterium-produced human insulin is now readily available.
I don't know the relative prices.

-It is a very long jump from the lab to tons and tons of paper pulp which
-may be none too sterile. This particular dream (cellulose ---> ethanol) has
-been around for a long time.  I, for one, will believe it when someone
-actually makes a buck on it. 

I should have listened to the report more carefully - I was driving, and
couldn't really take notes. I believe one point that was emphasized was
the wide assortment of junk the bacterium will eat. (I don't know whether
the material has to be sterilized first.) The plans for building a conversion
plant seemed pretty definite.

I brought this up in reference to the discussion on Earth resources vs
space resources, but I suppose exotic genetically altered organisms could
be important in recycling and in setting up working ecosystems in space.

John Roberts
roberts@cmr.ncsl.nist.gov