Okay. I'm going to go out on a branch here. This could be totally wrong now. And it is also an answer to how I perceive your question, Kevin2000. I could be WAAAYYY off though.
The use of these carbon sources, such as sucrose and ethanol, get directly used as immidiate energy so they can process their "food" (nitrates, phosphates, etc) for more carbon source energy so they can keep on living and reproducing. It's a give and take situation. You give it the "power" to live, and it will live harder/better. And in order for it to live, it needs to "digest" those simple organic compounds that we have building up in our tanks into something useful. Here is an example, and please pardon the adolescense of it. But think of this scientifically, please. It's the only useful example I can think of. Sperm store and use simple sugars (sucrose if I remember right) that is also found in the semen in order to power themselves to achieve their goal of getting to the egg and fertilizing it. You can power-up these cells by adding excessive amounts of simple sugar. They immidiately use it and you can see that in the statistical finding of doctors that study this. They are more aggressive and energetic to get their life goal finished. To put this in terms of our anaerobic and aerobic bacteria, when we add a carbon source they aggressively try to complete their lifes goal. Which in our case is use nitrates, phosphates, and other compounds to grow and reproduce. That is their life goal. We are just giving them the steroids to do it
But, as to why the carbon sources that Randy has listed are better than others is because they are simple compounds that are readily consumed by the bacteria. I'm sure you could add some other source, but it would have to break down into a simpler form first.
Now which bacteria is powered by what carbon source is better left to the real experts.
Now what I want to know is does the marine bacteria that uses these carbon sources to help reduce organic compounds store extra energy? Do they store it in their mitochondria (spelling?)? Do bacteria have mitochondria?
