I am looking for a gelling agent that can be used in place of agar, where its carbon must not be bioavailable for fungi. I have read about pluronic polyol f127 as substitute for agar. Can fungi metabolize carbon from this polymer?
1 Answer
It is known that some species of fungi can use hydrocarbons as their carbon source. Polyethers like pluronic are less chemically inert than hydrocarbons. Indeed, degradation of polyethylene glycols by microorganisms is a well studied process (see DOI: 10.1007/s00253-001-0850-2 for example). Gloeophyllum trabeum is known to degrade poly(ethylene oxide) by a non-enzymatic, oxidative process (Proc. Natl. Acad. Sci. USA. 1998, 95(18):10373-7). Given those facts, there is a very good chance that some species of fungi can metabolize pluronics and similar compounds.
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$\begingroup$ When you said that there is a very good chance that some fungal species can metabolize pluronics does that mean that most fungal species will not be able to metabolize pluronics? If that's the case then pluronics is ideal substitute for agarose as gelling agent for my study given that most fungi survive in agar. By the way, based from the structure, how can I tell whether carbon in a polymer is available for microorganisms? $\endgroup$– Jo DenCommented Jun 24, 2016 at 13:43
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$\begingroup$ Well I can't tell exactly how many species is able to metabolize polyethers, but I wouldn't be surprised if most of them can. About stability: anything that contains hydrolysable bonds (amides, esters and hemiacetal ethers) is potentially prone to biodegradation. Also chemical groups that can be oxidized - like alcohol groups in pluronics are good targets for enzymes. But that free-radical oxidation system described in the second reference is able to attack practically any organic molecule, so your only choice is to test several gelling agents with your particular species of fungi. $\endgroup$– vapidCommented Jun 27, 2016 at 8:14