Genecor and DuPont, and Dupont and Tate & Lyle are making 1,3-propanediol biochemically from glucose derived from corn. Genecor uses an E. coli
strain for the conversion. The reference linked below gives a nice summary of a University of Wisconsin study whereby several bacterial species were
evaluated for 1,3-propanediol producing capability using glycerol as substrate. Among those successful were Kiebsiella pneumoniae and
Citrobacter freundii.
I'm not interested in K. pneumoniae as I understand it is a pathogen, even though it gave the best yield: 63%. The C. freundii, which seems much
more benign for the home chemist, gave a 39% yield.
My question: Is C. freundii harmless enough for the home chemist to use, assuming he has no formal training in the use of bacteria?
[Edited on 5-10-2008 by Magpie]chemoleo - 5-10-2008 at 17:01
It certainly seems very common throughout nature...I was about to dig out heavy references, but even Wiki says
"he species C. amalonaticus, C. koseri, and C. freundii use solely citrate as a carbon source. These bacteria can be found almost everywhere in soil,
water, wastewater, etc. It can also be found in the human intestine. They are rarely the source of illnesses, except for infections of the urinary
tract and infant meningitis." Ok in a few cases in 10000 they led to real symptoms, but I imagine, these were immuno-compromised patients with a
genetic susceptibility.
I wouldn't worry, given they are everywhere anyways. How are you going to isolate the species?
If you are out of ideas - I'd suggest making a solution of pure citrate in H2O (preferably ammonium potassium citrate, to introduce a few ions), and
infect it with some wet healthy soil. Then keep reinocculating similar solutions (but heat sterilised) to ensure that the only thing that grows well
in there is the bacteria that already grew in the initial occulate.
[Edited on 6-10-2008 by chemoleo]Magpie - 5-10-2008 at 19:25
Quote:
I wouldn't worry, given they are everywhere anyways. How are you going to isolate the species?
Thanks. That's what I suspected but wanted some confirmation from a professional who works in the field. C. freundii is available from biological
supply houses for about $9/tube.
What I liked about the UW paper is that it gave all the conditions, nutrients, etc, needed for the conversion. I'll have to take another look to see
how difficult it will be to isolate the 1,3-PD from the final broth.chemoleo - 6-10-2008 at 18:46
Yes, that's very nice that they give the info. It's actually fairly standard for bacterial growth, they even use soy extracts (cheap!) which contain
presumably all the vitamins required for efficient growth.
Given that you can simply order this bacterium (what's the source?) this is definitely the best route, as you won't have to spend time on finding
& isolating those species that can live on citrate alone (which is what I meant with my suggestion above). Glycerol is used instead in the article
presumably because of its availability from biodiesel production... and it works because it is a metabolic product of glycolysis (well, it is
derivatised into phosphorylated forms).
