Re: [DIYbio] is BioGlow being realistic?

Well I'm not a biohacker, it would be interesting to be but it's only a fantasy for me. From a marketing standpoint though, the amount of light produced is entirely inefficient. It might be enough if they got a whole lot of them and set them in a row, window on one side, glass on inside on the other, with the plants set up in between with a hydroponic system of sorts. It'd be pretty and that's half the battle. There's no way they could sell it as a streetlight at this point, maybe if you can get it brighter and in vine form guys. That would be a beautiful mix of concrete and plants though, huge vines of glow in the dark plants over the walls... You'd just have to make sure it won't grow horizontally or the maintenance cost would dismiss it. For all that matters, you could sell it to individual businesses to place it over their storefronts, it'd require daily maintenance but would be a statement to their "green" interest, and that would be the point you'd sell it on. If they can make something that forces the plant to stop growing at a certain length or at a certain type of barrier, some kind of emission or light at the bottom of where you want it to stop growing or something I couldn't think of. Feel free to use my idea, no credit of any form necessary, though it would be nice. :) 

On Wednesday, September 3, 2014 8:50:40 PM UTC-5, Nathan McCorkle wrote:

Does you post title refer to that quoted text? Or are you citing quote
to reinforce that it doesn't seem realistic? I actually thought you
were quoting someone at BioGlow, but from googling it seems the author
is just some tech media writer:
http://arstechnica.com/science/2013/04/why-your-streetlights-wont-be-replaced-by-glowing-trees-anytime-soon/

His analysis seems decent, he notes inefficiencies know and the math
is simple enough.

Certainly with enhancement a few of the points he makes could be
moot... namely the omni-directional character of the light emission
seems like something that could be improved upon, first by moving
expression to some cells on the lower part of the leaves (stomata
maybe), then by controlling the direction the emission complex points
toward. That can all be done in parallel with biochemistry tweaks for
the metabolics.

He also doesn't really go into the 'one-time' costs like enzymes
(these won't actually be one-time costs, but they certainly aren't
quite recurring costs in the same way as the small-molecule energy
transporter is), but somehow determines that only 5% of the energy
involved in luminescense will be photon output, that seems quite low
to me for a system that is based on catalysts (but I really don't
know).

If you assume the machinery is a fixed non-recurring cost, and the
pathway is 15 metabolic steps long (I don't know how many steps it
actually is from common plant molecules), and the assumption is 5%
energy making it to photons, you get an average thermodynamic
efficiency per-metabolic-step of 81%.

I don't honestly know if that is realistic or not. I tried searching
for info on heat/thermal production/waste, or enzyme energy savings,
but I think my search terms were lacking in specificity, as I was
getting more hits enzyme efficiency as related to the speed or
completeness of reaction, rather than % energy to heat. I can't
remember if I want to search for something about Gibbs free energy or
something... I have been bad about memorizing chemistry.


--
-Nathan