Inorganic Carbon to Reduce Phosphate & Nitrate?

[bertoni]

Indeed! This thread has been very interesting!

[pjf]

Originally posted by mesocosm
It is also perhaps worth pointing out that any quest in search of maximizing assimilatory nitrate and phosphate reduction is going to be much more engaged with heterotrophic microorganisms. Why the focus on autotrophs?

It is natural to focus on autotrophs for nitrate export because the notion of skimming nitrate-assimilating phytoplankton is obvious. In refuges, it is common to prune macro-algae for nitrate export. Phytoplankton can be considered a skimmable form of such photo-autotrophy.

The notion of skimming heterotrophic microorganisms for nitrogen export is less obvious. In wastewater treatment, methanol or molasses are dosed to provide organic carbon to anaerobic heterotrophs that reduce nitrates to N2 gas (http://www.methanol.org/pdf/wastewater.pdf, http://www.swhydro.arizona.edu/archi...1/feature4.pdf). In aquaria, the skimming of anaerobes from live rock or deep sand beds is neither desirable nor practical.

We still need to identify the microorganisms that carbon dosing promotes in the aerobic water column of an aquarium. Aerobic heterotrophs are normally associated with the consumption of oxygen and organic materials to produce CO2 and inorganic nitrogen. It would be valuable to measure the impact of carbon dosing on ammonia, nitrite and dissolved oxygen levels.

[wilsonh]

This should be thread of the month!

[mesocosm]

Greetings All !


In order to avoid a massive (irritating) post, I'm going to come at this in pieces. Hope folks don't find this too annoying.

Originally posted by pjf
It is natural to focus on autotrophs for nitrate export because the notion of skimming nitrate-assimilating phytoplankton is obvious. In refuges, it is common to prune macro-algae for nitrate export. Phytoplankton can be considered a skimmable form of such photo-autotrophy. ...

Ahhhh, now I get where you're coming from ... excellent!


Benthic algae have indeed been documented as superior competitors for ammonia, in comparison to ammonia-oxidizing bacteria, here ...

Competition between Ammonia-Oxidizing Bacteria and Benthic Microalgae.
Nils Risgaard-Petersen, Mette H. Nicolaisen, Niels Peter Revsbech, and
Bente Aa Lomstein
Appl Environ Microbiol. 2004 September; 70(9): 5528–5537.
http://aem.asm.org/cgi/reprint/70/9/5528.pdf

Interestingly enough, such competitive superiority is not universal across the full range of algae vs. bacteria interactions. For example, some heterotrophic bacteria are documented as superior ammonia competitors (vs. algae) here ...

Utilization of inorganic and organic nitrogen by bacteria in marine systems.
Wheeler, P.A. and Kirchman, D.L.
Limnology and Oceanography 31:33, 998-1009, 1986
Abstract
http://www.osti.gov/energycitations/...sti_id=6586752

Additionally, it turns out that some bacteria can be superior competitors for P, as documented here ...

Competition along a Spatial Gradient of Resource Supply: A Microbial Experimental Model
C. T. Codeço and J. P. Grover
The American Naturalist, volume 157 (2001), pages 300–315
(Please trust me here ... the link requires a subscription ... sorry.)

These are the kinds of references that have caused me to focus on bacteria, instead of either microalgae or macroalgae, as the organisms that will give me greater efficiency in nutrient export ... JMO. While I agree completely that the physical export of algae is a much more straightforward thing (in contrast to bacterioplankton export), for me it's also a matter of the specific chemicals that need to be added to a tank to get maximum growth and respiration. Conceptually I'm more comfortable with the idea of dosing something like glucose for bacteria, than I am with dosing an ammonia compound for either macroalgae and/or microalgae as a way to maximize nutrient export ... just my preference.

For the record, there is a significant group of European reefkepers who much prefer what I do not ... they dose ammonium chloride as a way to overcome nitrogen limitation (see Jorg Kokott's fascinating multi-part series on nutrition in reef sysytems in Coral magazine). If I were pulsing small amounts of something like NH4Cl through a system, then a microalgae and macroalgae export focus would make lots and lots of sense (as in clearly superior to bacteria) ... on several levels.


JMO ... your mileage will vary.

[mesocosm]

Greetings All !

Originally posted by pjf
... The notion of skimming heterotrophic microorganisms for nitrogen export is less obvious. ...

As recently as four years ago I would have agreed completely without a second thought. But the emergence of bacterioplankton filtration configurations has totally spun my already twisted little mind on this topic. I fooled around with one of the bacterioplankton product lines on a ~70G system that was used for receiving transshipped corals. The system used less than 10 lbs of live rock and an ASM G-1 skimmer (hardly the most efficient skimmer toy selection) ... despite what I considered massive organic waste input, the Salifert N-compound test kits and Hanna PO4 meter barely twiched (... and restabilized within 12 hours). Freakin' extraordinary ... I'd never seen anything like it.

I've been data-mining on bacterioplankton concepts ever since ...


JMO ... many ways to achieve low nutrient water columns.

[mesocosm]

Greetings All !

Originally posted by pjf
... In wastewater treatment, methanol or molasses are dosed to provide organic carbon to anaerobic heterotrophs that reduce nitrates to N2 gas ...

I knew you'd be worth talking to ... wastewater treatment and fish mariculture operations have been utilizing carbon dosing strategies for quite a while. Asian aquaculture operations have been using molasses extensively for decades. While molasses never quite caught on in the United States, the use of methane to overdrive wet-dry filters and fluidized sand beds has been extensive. While the big kids have no problems with such a strategic choice, reefkeepers still have dificulty experimenting with it ... go figure.

BTW, guess which RC userID has arguably posted more documentation about this type of stuff than anyone else? ...

... Boomer

Originally posted by pjf
... In aquaria, the skimming of anaerobes from live rock or deep sand beds is neither desirable nor practical. ...

I couldn't agree more ...


JMO

[mesocosm]

Greetings All !

Originally posted by pjf
... We still need to identify the microorganisms that carbon dosing promotes in the aerobic water column of an aquarium. ...

Indeed ...

I'd suggest that any initial set needs to include these ...

Phytoplankton
Diatoms
Dinoflagellates
Cyanobacteria

Bacterioplankton
Bacteria
Archaea


Given the intimate relationship between the above listed groups and zooplankton, and the susceptability of zooplankton larvae to export via skimming, I wonder if some zooplankton might also need to be included.

Looking forward to reading other opinions.

[mesocosm]

Greetings All !

Originally posted by pjf
... It would be valuable to measure the impact of carbon dosing on ammonia, nitrite and dissolved oxygen levels.

The use of "growth" and respiration as measures of the effects of "carbon dosing" is actually pretty extensive. But a tiny sampling ...

Nutrition and Metabolism of Marine Bacteria
I. Survey of Nutritional Requirements
Robert A. MacLeod, Eva Onofrey, and Margaret E. Norris
1954
Full Article
http://jb.asm.org/cgi/reprint/68/6/680.pdf


Consumption of dissolved organic carbon by marine bacteria and demand for inorganic nutrients
Ulla Li Zweifel, Bo Norrman, Ake Hagstrom
Marine Ecology Progress Series
Vol. 101: 23-32, 1993
Full Article
http://www.int-res.com/articles/meps/101/m101p023.pdf


Inorganic nitrogen utilization by assemblages of marine bacteria in seawater culture
S. G. Horrigan, A. Hagstrom, I. Koike & F. Azam
Marine Ecology Progress Series, Vol. 50, pp.147-150
1988
Full Article (pdf)
http://www.int-res.com/articles/meps/50/m050p147.pdf


Want to tap into one of the online informational "motherlodes" regarding the nutrition and metabolism of marine bacteria? Check out the links to MacLeod's stuff from this Google search:
http://scholar.google.com/scholar?as...j=all&hl=en&lr


But there's a rub ... I remain uncertain as to the direct applicability of such hard data. Clearly something fundamental is going on, but translating that awareness into practical husbandry remains elusive to me. The sugar/vodka tangent, while useful in a limited way, is a dead-end in terms of maximumizing efficiencies. There exists a serious gap between the academic research literature, and the proprietary formulae of various manufacturers. Until something bridges the gap, we're almost ... but not quite ... stuck.

Even so, participants in cyber-reefkeeping communities are doing some pretty extraordinary things in a variety of aquaculture realms. It's my hope that by posting this kind of reference materials that components of the bridge can begin construction.

We'll see ...



JMO .. HTH

[pjf]

Originally posted by mesocosm
But the emergence of bacterioplankton filtration configurations has totally spun my already twisted little mind on this topic. I fooled around with one of the bacterioplankton product lines on a ~70G system that was used for receiving transshipped corals. The system used less than 10 lbs of live rock and an ASM G-1 skimmer (hardly the most efficient skimmer toy selection) ... despite what I considered massive organic waste input, the Salifert N-compound test kits and Hanna PO4 meter barely twiched (... and restabilized within 12 hours). Freakin' extraordinary ... I'd never seen anything like it.

You are a fountain of very valuable theoretical and practical information!

The bacterioplankton filtration that you describe seems superior to the refugiums, reactors and protein skimmers that aquarists normally use. I would be interested in links to this type of filtration.

Thanks!

[mesocosm]

Greetings All !


Before suffering through the marketing hype of the various proprietary bacterioplankton systems, I would suggest at least a moderate exposure to some of the historical discussions about these various product lines. Here's a representative example of the kinds of "classic" threads that I'm talking about ...

dosing vodka to bring down N and P
(RC, frankdreistein, 12.25.2003)
http://archive.reefcentral.com/forum...5&pagenumber=1

Originally posted by pjf
... The bacterioplankton filtration that you describe seems superior to the refugiums, reactors and protein skimmers that aquarists normally use. ...

I'm unable to assert the superiority of one captive marine ecosystem equipment configuration or husbandry philosophy ... too much depends on the unique circumstances, preferences, and intentions of the user. For me, they're all just a different set of tools anyway. The type of organisms that are to be maintained is also critical ... these systems are primarily intended for the culture of Acropora species, their relatives, and organisms with similar environmental needs.

Originally posted by pjf
... I would be interested in links to this type of filtration.

The current list of such product lines include:
ELOS
PolypLabs
Prodibio
Ultralith System (Fauna Marin)
ZEOvit System (Korallen-Zucht)


As you might imagine, most of these systems have been discussed in RC. Examples of such discussions include ...

my house reef (211 g.)
(RC, Iwan, 11.01.2005)
http://archive.reefcentral.com/forum...hreadid=700454

Prodibio
(RC, bosborn1, 03.25.2006)
http://archive.reefcentral.com/forum...5&pagenumber=1

DARK's 210g on Polyp Labs System Reef-resh and Reef Roids
(RC, DARKPHREAK, 04.04.2006)
http://archive.reefcentral.com/forum...hreadid=817441

ZEO...ZEO...ZEO...ULTRALITH System !!!
(RC, Aquarium Obsessed, 08.13.2006)
http://archive.reefcentral.com/forum...hreadid=905996

Can we talk about Zeo, if we promise to be civil?
(RC, kabbord, 06.06.2005)
http://archive.reefcentral.com/forum...ghlight=zeovit


I would strongly urge you to research these systems ... for yourself ... before engaging the marketing strategies which are inevitably associated with all of these products. A simple Google search using the product line keywords listed above will yield more commercial link hits than you can shake a gorgonian at.

The proprietary nature of many of the components of these systems makes critical evaluation difficult ... compounded by the refusal of manufacturers and distributors to present non-revelational (with regards to legitimate proprietary information), replicable experimental results. Not that this isn't the "industry standard" ...

... seen any objective, replicable skimmer performance data lately? ...

It is also perhaps worth noting that many serious reefkeeping minds consider these types of products along a continuum ranging from innocuous to fraudulent ... including folks like Dr. Randy Holmes-Farley and Eric Borneman. The history of some of the discussions regarding these products have been "controversial" ...

... to say the least ...



JMO ... HTH

[Boomer]

Meso

BTW, guess which RC userID has arguably posted more documentation about this type of stuff than anyone else? ...

... Boomer

Yah but now I leave it you to you and think you are ahead of me















Yeah wait

It is not me but my evil twin and good buddy Bomber He has left RC Meso and is now over at The Reef Tank as Spanky. I just talked to him on the phone not to long ago. People always get us confused. He is the Bacteria guy from NOAA, a retired Marine Pathobiologist.

[wilsonh]

I noticed he's not been around I used to like his threads (when I had a few spare hours LOL)

How come he left RC?

[Boomer]

It had to do with Eric Borenman and Ron trying to find out who he really was and Eric deleting his posts, which he had not write to do. There was lots of posts on it so he just decide to leave and more or less Eric got booted off of RC and Ron went with him

[wilsonh]

Oops! One of those kind of things!

Looks like I missed the whole thing, anyway better leave it at that, enough said.

Back to the topic!

[pjf]

Originally posted by mesocosm
I fooled around with one of the bacterioplankton product lines on a ~70G system that was used for receiving transshipped corals. The system used less than 10 lbs of live rock and an ASM G-1 skimmer (hardly the most efficient skimmer toy selection) ... despite what I considered massive organic waste input, the Salifert N-compound test kits and Hanna PO4 meter barely twiched (... and restabilized within 12 hours). Freakin' extraordinary ... I'd never seen anything like it.

I agree that there is a lot of hype in the realm of proprietary systems. Thanks for sifting out the chaff.

I'd be interested in the bacterioplankton product that you had such success with. Which one was it? What bacterial culture was used and where did you acquire it from? Did it require carbon dosing?

Thanks!

[mesocosm]

Greetings All !


pjf ... fair enough, but I'm entirely uninterested in getting into the details of specific proprietary product lines. I'm interested in the principles, and research documentation, which underlie such product lines. That being said ...

Originally posted by pjf
... Which one was it? ...

The ZEOvit system from Korallen-Zucht.

Originally posted by pjf
... where did you acquire it from? ...

CaptiveOceans.

Originally posted by pjf
... What bacterial culture was used ...

ZeoBak.

Originally posted by pjf
... Did it require carbon dosing?

Yes.


If this degenerates into a ZEOvit thread, sorry, but I'm out.
No offense ...



At the risk of continuing to be one of those userIDs who has just too much to say ...the issue of "bacterial culture" deserves a bit more detail. The product I used is called ZeoBak, but as to, "What bacterial culture was used" ... well ... that's a whole different question.



Which specific product is trivia ... it's about the biofilm. And the biofilm ain't proprietary ...



The nutrient reduction behavior that I observed was not the result of a proprietary bacteria inoculation, snake-oil potions, or magic rocks. It was the result of the behavior of the entire bacterial guild within the tank ([biofilm composition] + [system environment]). The inoculation of a specific product was but one single component of what is fundamentally a multi-variable process. A meaningful part ... to be sure ... but just one part. I view other aspects as equally (if not more) important as the specific identities of the bacterial strains (... with the notable exception of strain coding for element/compound specific siderophores, and siderophore-like proteins and receptors. This is the aspect which may indeed allow a bacterial strain to be considered as "special").

Aspects like ...

... how mass transfer is taking place in the system. The intensity and pattern of "flow" within an aquarium can exert a profound effect on the pattern(s) of nutrient uptake;
... the presence of a culture vessel (so-called "reactors") which functions to: (a) facilitate bacterial attachment and biofilm formation, and, (b) detach bacterial biomass to make it available for macro-aggregate formation, export (via skimming), filter feeding, and entrapment in coral mucus nets;
... the impact of the periodic pulsing of a bacterial biomass (inoculant) on the composition, metabolic/respiration behavior, and competitive interactions of the biofilm throughout the ecosystem;
... the impact of the periodic pulsing of carbon source(s), nutrients, and vitamins on the metabolic/respiration behavior of the biofilm.

JMO ...



BTW ... for folks wondering what the heck a "siderophore" is ...

A Siderophore (greek for iron carrier) is an iron chelating compound secreted by microorganisms. Iron Fe3+ ions have a very low solubility at neutral pH and therefore cannot be utilized by organisms. Siderophores dissolve these ions as soluble Fe3+ complexes that can be taken up by active transport mechanisms. Many siderophores are nonribosomal peptides.

http://www.google.com/search?hl=en&q...re&btnG=Search

Also see ...

Chelation, uptake, and intracellular binding of trace metals
PEI / CEBIC
http://www.princeton.edu/~cebic/chelbindadvanced.html

It should also be noted that research has documented siderophore-like protein structures and receptors in marine bacteria which grab other stuff out of the environment. Stuff like ... [drum roll] ... various phosphorous containing compounds. Folks in reefkeeping cyber-spaces post as though cellular growth is the only thing going on with bacterial nutrient export. I would argue that there's a lot more going on.

A whole lot more ...



JMO ... HTH

[Serioussnaps]

I am on the second page of this thread, but I have to say this is by far the best thread I have ever read on RC. I demand a sticky!!!!!!!!!!!!!!!!!!

[Boomer]

One thing I like about Meso, he does not hold back and tells it all

[Canarygirl]

A lot of this thread is overwhelming to a non-scientific mind like mine, I'm better with a limited amount of general science and then the practical application to husbandry. Not that I'm complaining about the contents of this thread, I'm just jealous that I can't assimilate it all...

Question about these bacterial filtration systems. I've always wondered why they are dependent on weekly water changes instead of bi-weekly, for example. Do you think it has to do with the oxygen consumption of the bacteria culture? Or just one more means to export the bacterialplankton and the bad stuff they've sucked up from the system? I am trying to research and evaluate whether it's worthwhile to use one of these systems, since I can't imagine ever doing weekly water changes. I'm a bi-weekly kind of person, myself....

[mesocosm]

Greetings All !

Originally posted by Canarygirl
A lot of this thread is overwhelming to a non-scientific mind like mine, I'm better with a limited amount of general science and then the practical application to husbandry. Not that I'm complaining about the contents of this thread, I'm just jealous that I can't assimilate it all...

A lot of folks have made the same comment. The reason that it looks intimidating is that ... well ... it is. But once you get used to the jargon I suspect that you'll find that it tends to become pretty straightforward. Despite my brain-washing ... errr, training ... as a biologist, I still find having another browser window open so that I can Google or Wikipedia the terminology to be very helpful. A "define:" command in front of a keyword in Google's Basic search engine interface works wonders. I've also found persistence to be critical. Mulder was right ... the truth is out there ...

JMO ...

Originally posted by Canarygirl
... Do you think it has to do with the oxygen consumption of the bacteria culture? ...

The only time I've seen "oxygen consumption" issues is when the carbon source has been overdosed. Starting the dosing regiment a little lower than manufacturer recommendation mitigates the issue, and allows a little better time cushion to get a feel for how the ecosystem is responding.

I think most peoples' experience is that these kinds of products are much more "interactive" than the kind of experience that one gets with a straightup Berlin-style system (for example). This was my experience ... I found myself tweaking the manufacturer dosing recommendations within the first two weeks. I enjoy this type of reefkeeping style immensely. It's also perhaps worth noting that I've come across several posts from people who just didn't like this aspect of these kinds of methodology, and it caused them to choose another style for their system.

Many ways to skin an Acropora ...

Originally posted by Canarygirl
... I've always wondered why they are dependent on weekly water changes ...

I'm not so sure that they're "dependent" on weekly water changes. I've always viewed weekly water changes as just another component of most "good" husbandry philosophies. The various product lines require "good" husbandry practices, and appropriate mechanical toys ... just like any other useful reefkeeping methodology or philosophy. I've never really understood the historical objection to manufacturers pointing out that good husbandry is required to allow their products to function properly. The notion that the necessity of "good husbandry" invalids the utility of a product is a non sequitor.

That being said, there is another "aspect" that has begun to emerge in some discussions during the last year ... so-called ionic or elemental "balance". The notion is that the enhanced bacterial behavior (both growth and respiration) consumes various elements rapidly, and that water changes function to help replenish those elements. There's even a synthetic salt mix out there which claims to lessen the water change requirements by generating "balanced levels". Tragically, such products typically offer no replicable evidence for their marketing claims (see previous post about hard skimmer data).

It might also be pointed out that my objections to the failure of manufacturers to present replicable data in support of their marketing hype doesn't demonstrate that their claims are inaccurate. My objection merely highlights the notion that such sales-oriented claims are, at the very least ...

... suspicious.

Originally posted by Canarygirl
... Or just one more means to export the bacterialplankton and the bad stuff they've sucked up from the system? ...

I don't view the water change aspect as being a specific filtration aspect. I view it in terms of a water column chemistry aspect.



JMO ... HTH

[Mr31415]

mesocosm - great thread. One of the reasons I spend most of my online time on RC - there are some people (incl. Boomer and Bertoni) who really knows their stuff and can back it up with scientific explanations and studies performed elsewhere.

My local forums lack this kind of expertise and I really, really appreciate you guys' time and effort sharing knowledge.

[Canarygirl]

Hi Meso...thankyou for your response and the tip about searching out terms explanations.

About the weekly water changes, I reviewed the Zeovit Guide yesterday and saw that section about the one particular salt (Reefer's Best) that allegedly reduces the need for water changes to a bi-weekly change of only 5%. The guide said the water change was not to export but to import the needed elements from fresh salt mix--like you said above. This RB brand supposedly is perfectly balanced so that a weekly water change is not needed. I looked at that salt briefly on an online vendor and it was $89 for a large bucket not including shipping. I hate to imagine the shipping costs... I have not heard of this salt before as one of the top tier favored brands.

[Serioussnaps]

What about this?

http://en.wikipedia.org/wiki/Lysogeny_broth

http://www.bcm.edu/physio/lab_pages/...protocols.html

We are kicking the idea of experimenting with it in a closed aquaria appliction. Tell me what you all think?

[mesocosm]

Greetings All !


This one is a little "heavy", but it highlights some important stuff ...

Nitrogen Cycling in Coastal Marine Environments
Chapter 11: Nitrate Reduction and Denitrification in Marine Sediments
Isao Koike and Jan Sorensen (edited by T. H. Blackburn & J. Sorensen)
John Wiley & Sons, Ltd., 1988
http://globalecology.stanford.edu/DG...ke_251-274.pdf

Note ... all the direct quotes that follow are from this article.


Why am I making a trans-light jump from inorganic carbon dosing to facilitate assimilatory reduction of NO3 and PO4 (remember how all this started? ... hehe ...), to an article on the behavior of bacterial populations in marine sediments ... in pelagic, coastal, and estuarine environments ... in localities ranging from the Western Pacific to the Bering Sea? Because this article highlights the kinds of difficulties we're up against as we try to "translate" the research data into something useable in our aquaria.





Putting the differences between "free-living" and attached bacterial populations aside for the moment, a couple of things from the article may be helpful to folks who are just being exposed to this stuff ...

Much effort has been made to explain the porportioning between the two processes in situ; apart from the composition of the NO3-reducing population, the likely control factors seem to include the actual NO3 concentration in situ and the carbon:NO3 ratio of the sediment.

Thing #1: There really shouldn't be any question that altering the C:NO3 ratio has the potential to positively effect the processes that reduce NO3 in a marine aquarium's water column. Organic carbon is clearly a potential control factor ... in a way that acrylic and other technical toys are incapable of being (.. with perhaps the exception of an ozonier unit).

In coastal sediments, which are physically disturbed by the burrowing fauna, the NO3-reducing bacteria could include both an endogenous population of NO3 reducers and a population of aerobes which happen to possess the genetics for NO3 respiration. Finally, the NO3-reducing population may also include some of the strict anaerobes like the SO4-reducers which are capable of dissimilating the NO3 to NH4, but are unlikely to utilize the activity unless NO3 is introduced into the deeper sediment layers.

Thing #2: The set of micro-beasties we're talking about is potentially vast ... vast. Aerobes, facultative aerobes, obligate anaerobes ... we're talking about a potential set of very diverse bacterial populations ... all of them working together in ways which are both enriching & inhibitory ...

... all at the same time ...

For instance, both the organic substrate composition and the carbon: NO3 ratio of the media may be important in order to determine if the predominant organisms are denitrifiers or the type which reduces NO3 to NH4. As an example of a selection on carbon-rich medium, the use of Difco nutrient broth with N03 gave a predominance of the Aeromonas-Vibrio group and, in smaller fractions, other enteric organisms and pseudomonads (Dunn et al., 1980; MacFarlane and Herbert, 1982, 1984).

As an extension of this work, continuous culture enrichments may be used to find the organisms which are best adapted for particular conditions. The sediment from an estuarine mud flat was shown to produce mainly fermenting, enteric organisms when glycerol was used in a carbon-limited chemostat (Dunn et al., 1980). In contrast, a predominance of oxidative pseudomonads was seen only when acetate was used as the carbon source. As a further complication, the product of NO3 dissimilation by fermenting bacteria may be either NO3 or NH4 depending on the carbon:NO3 ratio ofthe medium. Using isolates of both the Aeromonas-Vibrio group (MacFarlane and Herbert, 1982) and other enteric organisms (Herbert et al., 1980), there was a complete dissimilation to NH4 only when the nitrogen was limiting growth. In contrast, the NO3-reducing activity was not induced and NO3 accumulated in the medium when the carbon source was in short supply. Thus, even if the fermenting bacteria can dominate numerically, and contribute to the NO3 reduction in the sediments, they do not always express their NO3-reducing capacity.

Thing #3: Specific carbon sources can have profoundly different effects on different bacteria populations within the same ecosystem.

It should be mentioned, though, that Koike and Hattori (1978a) reported a significant incorporation of N03 and N02 into particulate nitrogen in coastal, marine sediments and further studies are needed to clarify the role of assimilatory N03 reduction in the sea bottom.

Thing #4: The type and concentration of particulates in the water column can have a profound effect ... profound ... on assimilatory NO3 and PO4 reduction.

For folks contemplating a bacterioplankton configuration for their own system ... Thing #4 is important. There is the potential for a significant operational/performance difference between bacterioplankton systems which incorporate a component to generate particulates in the water column ... as compared with the bacterioplankton systems which do not incorporate such a component.

Additions of peptone, glucose and amino acids to organic-rich, coastal sediment gave no significant stimulation of the denitrification, however, and the limitation by organic substrate availability may in such cases be of minor importance (I. Koike and A. Hattori, unpublished).

Thing #5: The C:N:P ratio within the water column of a marine aquarium can make the application of a bacterioplankton filtration product line very unsatisfying, as in ... useless.

Which takes me to the next post ...


JMO ... HTH






Time out ... digressive tangent alert. Anyone remember solbby's post in the SPS Keepers forum a few months ago when he mentioned that some of his bacteria-skimmate experiement results might come across as "controversial"? Look at the quote with thing #3 ... no mention of either Nitrosomonas, or Nitrobacter.

From samples taken from the Western Pacific to the Bering Sea ... no direct mention of either Nitrosomonas, or Nitrobacter.

Think about it ...


Okay ... time in

[mesocosm]

Greetings All !

Originally posted by Serioussnaps
What about this? ...

Peptones and yeast, in and of themselves, are generally a dead end. This is why I presented Thing #2, and Thing #3 ... the generalized, historical media aren't specific enough, and sometimes they may be problematic. Bad things may happen if the wrong group of micro-beasties is enriched.

Remember the Gram Stain of ZeoBak thread? ... ...

Even so, I've not seen any specific posts on this, nor have I experimented with LB media myself ... so take this opinion FWIW. As you folks continue your examination of different components, I suspect that at some point you're going to need to consider electron donors, electron acceptors, and strain-specific substrates (apart from the single carbon source variable).

JMO ...




For what it's worth, this is one of the places where I've spent a lot of time looking at the different sets of potential media formulae:

Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH
(German Collection of Microorganisms and Cell Cultures)
List of Media Ingredients
http://www.dsmz.de/microorganisms/media_list.php



But before you go there, you may want to take a moment for a quick review of the Structure and Function of Prokaryotes, Nutrition and Growth of bacteria, Growth of Bacterial Populations, and ... especially ... Regulation and Control of Metabolic Activities sections of this one:

Todar's Online Textbook of Bacteriology
http://www.textbookofbacteriology.net/


JMO ... HTH