#23 increased toxicity of carbon source

[Adrienne Zweifel]

this can be a synonym of an existing "decreased growth rate" term since the phenotype would be visualized via growth.
An example is PMID:4886277- an author compares how well a strain grows on 3 different carbon sources, and finds that it exhibits slower growth on galactose. The authors conclude that there is a "slight toxicity of galactose when grown at 20C and 37C."

[Marcus]

Adrienne,
Can we discuss this one further? I am wondering if growth is a correct parent. What if, for example, toxicity is assessed for a developmental process? This would be incorrect. I also wonder if you intend for us to importe every potential substrate for this term, as we plan to do for the carbon utilization terms. This is not a problem, per se, but I am just wondering. Thanks!
--Marcus

[Adrienne Zweifel]

Is the type of example you had in mind something like whether a carbon source causes a toxic effect during sporulation? If so, that is a valid scenario, but toxicity of a carbon source during growth would be different from a toxic effect that would impede a developmental process, wouldn't you think? I need to think about this some more, so l guess we'll talk about this later.

I was not planning to make terms for every carbon source.

[Debby Siegele]

The phenotype described in PMID:4886277 is an example of a non-toxic compound being converted to an intermediate that builds up to toxic levels because a mutation creates a block in a metabolic pathway. The mutant described in this paper has a mutation that inactivates the GalT step of the galactose degradation pathway (http://www.ecocyc.org/ECOLI/NEW-IMAGE?type=PATHWAY&object=GALACTMETAB-PWY&detail-level=3). In the absence of GalT, galactose is metabolized to alpha-D-galactose-1-PO4, which accumulates and is toxic. The originally proposed term needs editing so it doesn't suggest that the carbon source was toxic in the parental strain.