As long as we have some scientists peeking at this thread again, I'd like to post these links & previous discussion about collagen production & VC:
There have also been recent suggestions that vitamin C encourages collagen production and may be doing so in corals and be a factor in why people are experiencing increased growth. In particular this article has been used to support that notion. There are also suggestions that the ascorbic acid is acting as an antioxidant and that this article also supports that.
http://www.pnas.org/content/105/1/54.full
"The addition of ascorbic acid to the culture media increased collagen production by â‰Ë" 40% in M. digitata cell cultures (4.4 Ã"šÃ‚± 0.2 weight percent collagen relative to total protein without ascorbic acid compared with 6.2 Ã"šÃ‚± 0.5% with ascorbic acid; P ≤ 0.01; Fig. 2"
here's another link that has been tossed around...
http://www.springerlink.com/content/8lp5y5e1kahpuqpe/
To me it seems that they're drawing incorrect conclusions, but that first paper is enough over my head that I don't feel confident in making a strong argument. Perhpaps they're onto something, I don't know, which is why I'm hoping for your input on the matter. I'm also very curious as to how the ascorbic acid could be acting as a carbon source.
Also, here are some random comments from others from that thread that have been bugging me a little and would also appreciate your input.
"yes, collagen is the tough, rubbery "skin" or structural body of soft corals which provides stability and resistance to deformation.
In hard or stony corals the collagen is "assisted" by spicules of calcium carbonate.
This is way many soft corals are low current loving species, because high current will force them to fold or collapse and is also why stony corals thrive in high current, their calcium carbonate infrastructure allows them to with stand it."
"Zoanthids rely heavily on collagen for structural support, as other corals utilize calcium carbonate. This might explain why the zoanthids start "melting" away while other corals do okay.
Think about it the structure of the zoanthid, tough rubber collagen skin on the outside, with a gelly like internal, if the coral is deficient in ascorbic acid and can't produce collagen skin, it would appear to be melting."
Here's one response in particular in relation to me feeling that the ascorbic acid is acting as a carbon source...
"I've been scouring text books, asking friends and searching online, for the life of me I can't find any info on adsorbate being used as a carbon source. I can't even find a possible chemical reaction or pathway that can reduce ascorbate back to glucose or any other sugar....I really don't think it is possible.
My friend whose conversation posted above is a biochemical graduate student, her work is actually in marine chemistry. I posed the question about ascorbic acid being a carbon source to her and shot it down after reviewing the literature on it.