sirdarksol

I have a question about bacteria, specifically
lactobacillus
Is there any way that this bacteria could serve the nitrogen cycle?

lew2000

Actually, Lactobacillus are Lactic Acid bacteria. I know that you know this already but since the following:The Nitrogen cycle works with the following bacteria (pH 7 or above); nitrosomonas which oxidizes the ammonia in the tank into un-ionized ammonia (NH3; nitrobacter breaks down the nitrites into nitrates; and if you have a nitrate reactor (creates an anaerobic area) where denitrifying bacteria break down nitrates into nitrogen gas, and Lactosbacilli work on lactic acid - it would have no benifit.

Pandora

It's been a long time since I took micro... but I thought lactobacillus produced lactic acid rather than feeding off it? I doubt they would be able to feed off nitrogenous wastes... I'm pretty sure they requires sugars to ferment, and were they able to perform nitrification the acid production might be a problem in an aquarium. We all know how much lactic acid hurts when it builds up in your muscles, I doubt the fish would be too happy living in it!
lol, though like I said it's been a while since micro so I could well be off the mark on something!

KyWildFish

Lactobacillus are very good for Genetic modification. They readily take up alleles and are regularly modified in the food industry to accomplish different tasks. They are primarily used for fermentation but can be used to soak up phages or produce different components of a longer fermentation process (think sauerkraut or pickles). Because this is a rather easy bacteria to work with its likely its modified for your little experiment. I would need to get into a micro lab, get a bunch of media and run a few tests on it to be sure, but I think it has been modified to complete the nitrogen cycle and output Nitrogen gas as a byproduct.
I will try and find more literature about the modification potential of Lactobacillus, but it will have to wait till tomorrow (I have to finish dinner and play hockey all night

sirdarksol

Excellent answers, folks. I appreciate the help.
Also, please keep them coming, if anyone has any other info they think is pertinent. Discuss, argue, come up with and shoot down theories. There is a very specific purpose (which KyWild's figured out) that I'm asking.
I knew the stuff was easy to play with, I just didn't know to what extent.

KyWildFish

I found your answer. Its heavy on the microbiology lingo, but I will break it down.

"Six strains of Lactobacillus fermentum and Lactobacillus plantarum were investigated for nitric oxide (NO) production. First, the potential presence of NO synthase was examined. None of the strains of L. fermentum and L. plantarum examined produced NO from L-arginine under aerobic conditions. Interestingly, all L. fermentum strains expressed strong L-arginine deiminase activity. All L. fermentum strains produced NO in MRS broth, but the NO was found to be chemically derived from nitrite, which was produced by L. fermentum from nitrate present in the medium. Indeed all L. fermentum strains express nitrate reductase under anaerobic conditions. Moreover, one strain, L. fermentum LF1, had nitrate reductase activity under aerobic conditions. It was also found that L. fermentum strains JCM1173 and LF1 possessed ammonifying nitrite reductase. The latter strain also had denitrifying nitrite reductase activity at neutral pH under both anaerobic and aerobic conditions. The LF1 strain is thus capable of biochemically converting nitrate to NO. NO and nitrite produced from nitrate by lactobacilli may constitute a potential antimicrobial mechanism"

This will be a tad lengthy but here is the jest. This is an abstract from a journal titled Applied microbiology and biotechnology from 2001, authored by XU J. and VERSTRAETE W. (have to give credit now that we are talking science here). What this paper discusses is the ability of different strains of Lactobacillus to reduce nitrate into NO, or Nitrogen gas. This is demonstrated using several strains under several conditions. The first condition was "anaerobic" which simply means without oxygen/air. The other condition was with aerobic, or with oxygen/air. I assume that the type of Lactobacillus you are questioning is similar to some of the mentioned species. I read your thread regarding the HiQ system and believe that the type of bacteria that you are using is a slightly modified version of one of these. Because you are having to re-inoculate the system of a regular basis the bacteria is probably of the obligate anaerobic variety. This means is HAS to be in an anaerobic environment to metabolize and reduce nitrate. The draw back is it wont survive long in an aquarium seeing that the oxygen rich water is cycled through the whole tank. I suspect that the "powder" you are introducing has some kind of oxygen binding property and can temporarily create an anaerobic environment in the towers, but I am not sure. The big take-away from the article is that Lactobacillus sp. of bacteria are not limited to metabolizing lactic acid as mentioned above. In fact, in my looking I found strains of Lactobacillus that are found in the GI tract, vaginal flora, mouth, food industry, medical/pharmaceutical industry, and more.

I will say a great thank you to sirdarksol for sending me on the hunt. I really enjoy microbiology and miss having reasons to dig up info like this.

lew2000

There are studies being done using strains of different Lactosbacilli and instead of using yeast using less costly nitrogen sources, Nitrogen is one of the sources along with different sucroses for the formation of lactic acid and fermintation. Secondarily as KyWild Fish talks about, there are strains of lactosbacilli that are facultative that can live/grow in reduced oxygen flow. I would be curiuos if Hi-Q would identify the strain of bacteria used - as when you get into using nitrate towers you also have to add regular doses of bacteria anfd there are other threads on the web with regard to systems that use specialized facultative strains of bacteria (none mention lactosebacilli, but specialized ntifitying bacteria) to nitrify/and remove nitrates. Also since UGF's have areas of low flow - will this ugf setup have the same problem? I am curiuos though, because there are threads for marine aquariums in regard to sand beds and the use of facultative bacteria - as nitrate concentratations from studies indicate that there is movement towards the plenum and are higher than in the general aquarium water.

sirdarksol

Thank you, KyWildFish. That wasn't too terribly heavy on the bio-lingo. That wasn't any higher than a 200-level college class.

One concern I have is one of the last lines, which suggests that this bacteria may actually convert some of the nitrate into nitrite (probably leftover from what couldn't be turned into gaseous nitrogen)

One of the ideas behind the towers is that they create a partially enclosed anaerobic system. The powder has nothing to bind oxygen.
I'm guessing, actually, that the issue is that the stuff will not do well in a fully aquatic environment.

Of course, we'll see when the official experiment is over, because the secondary experiment is to see whether or not it's just the zeolite soaking up the nitrates, and the tertiary experiment is to see if my aquarium's cycle crashes when I run out of BioMagic.

Angela_96

I will let my husband answer when he gets out of the woods this evening, he has a BS degree in bio/chem he should have a good answer to that question. In fact I am curious to what he says.