grow sps.........got milk?

[MarkoD]

Maybe the milk and honey are acting as a carbon source? I'm sure when the first person started dosing vodka, people freaked out

[tlhood]

I think someone on the thread hypothesized that the milk molecules were acting like a transport system for nutients, allowing more concentrated amounts to reach the polyps.

Or something along those lines.

[asylumdown]

Originally Posted by tlhood

I think someone on the thread hypothesized that the milk molecules were acting like a transport system for nutients, allowing more concentrated amounts to reach the polyps.

Or something along those lines.

If elements of that are true, I suspect it's a gross over-simplication.

first and foremost, there's not really such thing as a 'milk molecule'. What we perceive as 'milk' is a combination of sugars, fats, protein, and various enzymes all in an aqueous medium.

Further, which enzymes, and how much fat will depend on the kind of milk and whether or not it was pasteurized, as pasteurization inactivates most enzymes.

If we're going to hypothesize that something in that mix is a 'transport mechanism', it would be helpful to define what is meant by the term 'transport mechanism' and 'nutrient'. In biology, transport mechanisms are usually very specific to a particular pathway - i.e. a specific molecule designed to bind to a specific other molecule as well as fit in to a specific receptor. The only molecules in milk that are designed to directly interact with other molecules in milk are the enzymes, and they have very specific relationships with the fats, sugars, and proteins in milk - relationships specifically related to breaking said fats, sugars and proteins down, not 'transporting' them anywhere. Most of them are torched in the kind of milk you can buy at the supermarket anyway.

As for 'nutrients' - it's an open question whether any of the raw ingredients in milk can be used by corals directly. Corals can absorb mineralized nutrients like nitrate and phosphate as well as some amino acids directly from the water, but I seriously doubt they have any capacity to either absorb or break down a molecule like lactose. I suspect that the carbohydrates in milk such as lactose are broken down by bacterial pathways just like any other carbon source in a tank and not used directly by the coral. The fats are an interesting wild card though.

Milk has over 400 different fatty acids in it. I've never heard of anyone experimenting with adding fats to a reef tank, or how they interact with corals. milk fatty acids can have up to 18 carbon atoms per molecule though, so at the very least they'd make milk a very potent organic carbon source.

[asylumdown]

And I was just reading the wikipedia page on honey. Honey is basically just a super dehydrated glucose-fructose solution. What ratio of glucose to fructose will depend on what the bees have been feeding on.

I don't see how adding honey to a tank is any different than dosing sugar. What makes honey special is the fact that it's a "supercooled liquid', meaning that it remains in some sort of liquid form well below it's melting point because of the innate properties of super-saturated glucose-fructose solutions.

It does have amino acids in it, but according to wikipedia, they account for 0.05-0.1% of it's composition, so not exactly a major contributor. I strongly suspect that to dose the equivalent amount of amino acid via honey that you'd get from a single frozen cube of mysis shrimp, you'd need to add so much that your tank would crash in an opaque cloud of bacterial anoxia.

It's got a tiny fraction of organic acids (like 1% or less). They're pretty common organic molecules, like citric, lactic, formic and butyric acid. Perhaps they do something in a reef tank, but you'd be adding very, very small amounts of them at a 'safe' dose of honey.

but yah, as soon as that drop of honey hits your water, it stops being "honey". Everything that makes it unique as a substance, from it's texture to it's viscosity, to it's 'super-cooled liquid' state, to it's anti-microbial properties, is related to it being a super dehydrated sugar solution. Add a drop of honey to a body of water a trillion times it's volume and it's just sugar and a teeny tiny amount of other relatively common organic molecules.

As far as a sugar additive goes, it's probably no more or less beneficial than any other sugar molecule. Table sugar is sucrose, which is a glucose and fructose molecule stuck together, so you're not really adding anything different than when you add just regular old sugar.

[asylumdown]

hmmmmm, the more I read about this fat thing the more I'm intrigued:

http://www.int-res.com/articles/meps/76/m076p295.pdf

I highly doubt corals can take up fatty acids directly from the water, the ones they get externally likely come from food. However, while some marine bacteria have the metabolic pathway to synthesize the polyunsaturated fatty acids (PUFAs) that most animals can't make on their own, I've found another study that showed bacteria are certainly capable of absorbing it directly from the environment if it's present, and that it will change the lipid profile of the bacteria when it does.

I'd be interested to see if adding milk to a tank alters the lipid profile of the bacteria the corals were feeding on, and in turn altered the lipid profile of the coral. Increasing the supply of certain essential fatty acids that the coral doesn't make on it's own, or doesn't get enough of from it's zooxanthella might encourage different concentrations/expressions of pigment proteins.

I suspect the 'dangerous' part relates to the gigantic supply of carbohydrate in milk, and the huge amount of carbon you'd be adding to the water in general. It would probably be pretty easy to OD and kill things.

[kien]

I love me some good 'ol fashioned sciencey threads. Especially when Adam starts throwing down enzymes, lipids and acids, oh my !