Well, lessee here. 1 teaspoon = 5 mL, and 1 gallon = 3800 mL
(approximately). So, that's 5 mL into 19000 mL, if my math is correct.
That works out to about 1/4 mL per liter.

For some kinds of tissue culture work, it is normal to dissolve
certain chemicals in ethanol or other solvents because they do not
dissolve well in water. They are then dispensed and autoclaved normally
when diluted in the media. Due to the high level of dilution, not all the
alcohol boils off. As substantial quantities of ethanol, methanol, and
other solvents may be used to compound media (several mL in some cases),
it is likely that more than the concentration stated above (1/4 mL per
liter) remains in the media during autoclaving.

As a result, the constant exposure of plants to these solvents in
vitro is assured. Interestingly, there are morphological differences with
plants raised under these conditions, and there are different results with
different concentrations- showing that at least *some* of these solvents
do, in fact, remain behind. I've never tried to quantify them. Anyway,
these changes vary wildly between different plants.

That plants are capable of chemosynthesis is not unexpected;
orchids derive virtually all of their carbon from the sugars in the media-
it's sure as heck not from the 400 ppm carbon dioxide that gets in
through the vent. Even unvented tissue cultures will grow, with plants
accumulating more carbon mass than would ever be possible from the small
amounts of available atmospheric air. Other organisms use chemosynthesis
as well; while an undergrad, I attended one lecture from an astronomer
turned biologist who tried to poison freshwater mussels with organic
solvents like toluene. The concept was to develop a quick-and-dirty
bioassay for organic solvent levels in water. Remarkably, the mussels
survived high concentrations (the memory fails me, but 500 ppm of some
very nasty solvents), and grew faster than the controls. That the critters
were capable of chemosynthesis of aromatic organic solvents seemed the
most reasonable explanation. I remember the concentrations were so high
that there were problems maintaining such high levels of solvent in
aqueous solution.

The e-mail address in the header doesn't work. Sorry.

-AJHicks
Chandler, AZ