What Keeps The Bacteria Alive?

[Christine1014]

Okay, hopefully someone can help with a little discussion we've had going on in another post.

Say you've got some filter floss or a piece of sponge media or something from an established filter. What keeps the bacteria on it alive? Is it just an ammonia source, or does it require water flowing over it (which I suppose would provide oxygen)?

Some of the reasoning we've been throwing around on the other post (in the betta section -- someone asked about cycling an unfiltered tank, and could you just put a piece of filter media into the tank, laying it in the gravel). -- when the power goes out, we all stress about how to keep the beneficial bacteria alive when our filter stops running. I remember someone once mentioning pouring water over the media.

BUT - we know bacteria needs a food source ... which IS ammonia... (but there'd be an ammonia source in a tank w/ a power outage).... SO - what is it? What keeps the bacteria alive?

I'm just curious at this point, so any insight is welcome and appreciated!

 

[dizzied]

I believe it's just ammonia and oxygen. If a filter stops running, the water would become stagnant and deprived of oxygen.

 

[Liam]

The bacteria consume a lot of oxygen, so that’s why a piece of filter media left in unmoving water is of little if any use. Pouring water over the media works to supply the oxygen.

 

[Phaedra]

Aha! Here's the new thread! Lo and behold- informed replies!
We hadn't even taken oxygen into consideration, had we Christine? Great to know!

 

[Christine1014]

I know, I never thought about oxygen either until I was typing the post, and included it more as an afterthought! So look at that; we've learned something!

You know, if I'd have gotten into fish-keeping while I was still in school, I would have been a much better chemistry and biology student!

 

[Bignose]

Oxygen is vitally important, because the bacteria get their energy from oxidizing molecules. In other words, the bacteria could be surrounded by more food than they know what to do with, ammonia for one species nitrite for the other, but without oxygen the bacteria have no way of using the food. Also, with oxygen, the bacteria can use their reserves or they will start to consume one another -- i.e. the dying/dead bacteria in a colony can be a food source for the living ones. But, again, without oxygen, the bacteria cannot use the food as an energy source.

 

[krazie2004]

Just to add, the nitrobacter family also contain anaerobic strains which do not need oxygen to convert ammonia into nitrites. So theoretically(sp?) nitrification can occur without the presence of oxygen, although certain other compounds must be present usually organic.
There are also some bacteria who can convert nitrites and nitrates into Nitrogen gas which people proberbly cant notice as it is produced in very small amounts.

 

[Phaedra]

I know, I never thought about oxygen either until I was typing the post, and included it more as an afterthought! So look at that; we've learned something!

You know, if I'd have gotten into fish-keeping while I was still in school, I would have been a much better chemistry and biology student!

ROFL! I was thinking the same thing recently! Now that I know what fish keeping entails, I don't think I'd worry about letting my kids (if I ever had any, that is) have one- it's so educational!
Great information Bignose and Krazie, thanks so much for posting it!

 

[raptorrex]

Oxygen is vitally important, because the bacteria get their energy from oxidizing molecules. In other words, the bacteria could be surrounded by more food than they know what to do with, ammonia for one species nitrite for the other, but without oxygen the bacteria have no way of using the food. Also, with oxygen, the bacteria can use their reserves or they will start to consume one another -- i.e. the dying/dead bacteria in a colony can be a food source for the living ones. But, again, without oxygen, the bacteria cannot use the food as an energy source.

yep that about covers it, nice one bignose!!

 

[Bignose]

Just to add, the nitrobacter family also contain anaerobic strains which do not need oxygen to convert ammonia into nitrites. So theoretically(sp?) nitrification can occur without the presence of oxygen, although certain other compounds must be present usually organic.
There are also some bacteria who can convert nitrites and nitrates into Nitrogen gas which people proberbly cant notice as it is produced in very small amounts.

Please don't take this in the wrong tone, but this information couldn't be wronger. How can you convert ammonia, whose chemical formula is NH3 -- N for Nitrogren and H for Hydrogen -- to nitrite, whose chemical formula is NO2 -- again N for Nitrogen and O for Oxygen, without oxygen?!? You have to have oxygen, otherwise there is no convertion from ammonia to nitrite.

There are anaerobic bacteria that can go the opposite direction. That is, they can take nitrates and go backwards all the way to nitrogen gas as their energy source. I am pretty darn sure they are not in the nitrobacter class, which by the way recent research has shown isn't even the primary oxidizers in the home aquaria (see recent work by Hovanec for example). I am pretty sure that the anaerobic bacteria are not the same species/strains since most of them are killed pretty quickly in the presence of oxygen and oxygenated water. These are the basis of live rock/live sand in some saltwater tanks.