Survival of beneficial bacteria

[kilnakorr]

Hi

I recently saw a youtube video from a 'local' fish store. He recommended that filters should be dried out, as the bacteria can survive a long time,weeks, as long as oxygen was present, as in leave canister bucket open.

I can't seem to find any evidence or studies on this (other than very different bacteria), and wondered if anyone here has some insight?

 

[dean]

I don’t think they meant to let it dry out completely just tip it up and pour out the water so that the media remains moist

An aerobic organism or aerobe is an organism that can survive and grow in an oxygenated environment. In contrast, an anaerobic organism (anaerobe) is any organism that does not require oxygen for growth. Some anaerobes react negatively or even die if oxygen is present.
https://en.m.wikipedia.org › wiki


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[Simon Cole]

There are two types. Dependent anaerobes and optimistic anaerobes. It is actually very hard to get oxygen free conditions, so the majority fall into the latter category. When you store bacteria you are looking to stabilise the environment. Commonly this is done with fridges or freezers to avoid deleterious conditions. A key factor in a natural system would be whether the bacteria are digested by other microbes.

 

[kilnakorr]

I don’t think they meant to let it dry out completely just tip it up and pour out the water so that the media remains moist

Yes, completely dry out. I'm not sure I can translate the entire thing, but we are talking crispy dry.

 

[Witcher]

Filter media can be dried out and bacteria will survive in a form of spores which can withstand lots of extreme conditions, like completely lack of water for thousands of years, radiation, high temps and quite nasty chemicals.
In planet Earth surface conditions they're practically indestructible.

 

[sparkyweasel]

What is he trying to achieve by drying it out?

 

[zozo]

Closed, stagnant and wet finally will go rotting and that is a fairly similar but different form of decay involving different organisms. Meaning as long as there is water there will be life, that will eat, poop, reproduce and die again, the conditions make the changes for different organisms to come and go.

Thus as long as it is wet, stagnant and never refreshed you could say the bacteria in there thrive themselves to their demise and will die and be taken over by other nasties we need nor want.

A dry environment is a natural preservative, especially for organisms, good and bad both stop reproducing and become inactive. Hence Freeze drying is very common preservation method to store bacteria etc. in the pharmaceutical industry.

And the food industry, think of instant coffee and soup...

Even freeze-dried bacteria are available to us for decades already as instant filter start (soup).

It seems that a lot, maybe the majority of bacteria can survive a freeze-dry period and come back to life when moist becomes available again to them. I guess for the Kitchen princesses among us, instand yeast is a very good example.

 

[Simon Cole]

A slightly historic article, but I hope it could help you on your quest.

@sparkyweasel ... hoping to store filter media outside of filter.

 

[kilnakorr]

What is he trying to achieve by drying it out?

Its a part of a 'guide and tips' for bying used aquarium. Takes time before the tank is moved, cleaned, scaped and ready to be plugged in. Most people clean the filters very well and then goes through normal start, waiting for nitrogencycle to happen.
Just being sceptic as no mentioning of studies or tests.

 

[dw1305]

Hi all,

I don’t think they meant to let it dry out completely just tip it up and pour out the water so that the media remains moist

That's what I'd do.

Yes, completely dry out. I'm not sure I can translate the entire thing, but we are talking crispy dry.

I definitely wouldn't do this. Some bacteria might form resting spores, but work on Ammonia Oxidising Archaea (AOA) and bacteria (AOB) has definitely shown <"that they aren't resistant to drying.">

Treated soils were dried, incubated for three weeks, rewetted, incubated for a further three weeks and compared to untreated soils, maintained at a constant moisture content. Nitrate accumulation and AOA and AOB abundance (abundance of respective amoA genes) and community composition (DGGE analysis of AOA amoA and AOB 16S rRNA genes) were poorly adapted to drying-rewetting. AOA abundance and community composition were less resistant than AOB during drought and less resilient after rewetting..........

I'll see if I can find a reference for COMAMMOX Nitrospira, as they might be the most important nitrifying organisms.

cheers Darrel

 

[kilnakorr]

@dw1305 Thanks Darrel.
It could very well be a good approach. I've found several studies, but bacteria strains are very different.

 

[dw1305]

Hi all,

It could very well be a good approach. I've found several studies, but bacteria strains are very different.

My guess would be that there definitely are nitrifying microbes that are both resistant to drying, and used to a cycle of drying and re-wetting. I'd actually be reasonably confident that where-ever ammonia is available there will be a suite of organisms that can utilise it.

The would be a lot of natural situations where drying and re-wetting happens, seasonal streams, wetlands that dry out during the dry season, Rice paddies etc. The question I don't know is whether this applies to the microbial assemblage that you find in aquarium filters.

Again my guess would be that even in aquarium filters there are some AOA, AOB and COMAMMOX bacteria that are resistant to drying, purely because I think they will be in every environment. Because a filter sponge is normally a constantly wet environment I would suspect that the abundance of these is fairly low.

If you want an analogy I'll call it the "Killifish effect", you might find that Nothobranchius spp. are the only fish in a seasonal pond, but in the constantly wet pond next door there are Catfish, Lamp-eyes and Cichlids, and no annual Killifish.

cheers Darrel

 

[kilnakorr]

The would be a lot of natural situations where drying and re-wetting happens, seasonal streams, wetlands that dry out during the dry season, Rice paddies etc. The question I don't know is whether this applies to the microbial assemblage that you find in aquarium filters.

Yes. Finding info on denitrifying bacteria in agriculture where drying/re-wetting happens is easy. However, these are all very different stories as the soil has a great impact on the outcome, so not much relevant info.

 

[Simon Cole]

[comment redacted]

 

[Simon Cole]

I have changed my mind and hereby redact the opinion I expressed above. When I read back over my first honours project - I was measuring nitrous oxides and nitrogen gas in a range of soils and quite a few green waste composting windrows. I did find some of these gases and a correlation with carbon content. I'm embarrassed to forget my research , but then, I've had a hard week and would happily have claimed NASA never landed on the moon.

 

[dw1305]

Hi all,

and quite a few green waste composting windrows

Alternating aerobic nitrification/anaerobic denitrification is one of the big areas for research in wastewater treatment. Traditionally you had a spatial separation between the two phases, but a lot of research has gone into achieving both in the same vessel with a temporal separation.

The advantage of combining the processes is that you can have a plant with a smaller footprint and the anaerobic process reduces CO2 emissions and produces methane.

There is a good review paper <"A review on anaerobic–aerobic treatment of industrial and municipal wastewater">.

cheers Darrel

 

[Simon Cole]

Just read it, cheers Darrel. To me, the emission of nitrous oxide(s) is one of the "scariest" things about global warming. I've got no problem with methane emissions because it solves the greenhouse problem at the source end. But when the biodigestate is applied to land, that is when we shift towards far more dangerous emissions. N2O has a global warming potential (GWP) above 250. I seem to remember that when soils do not have adequate C:N ratio (partially a historical problem), you get a tendency for N2O above NO and NO2 - which if I remember correctly have far far lower GWPs ranging between 60 and 120 possibly.

The same thing happened when we shifted from locking carbon (and nitrogen) into landfill to composting and applying it to land. Everybody assumed that composting was green, when actually it was doing immense harm through global warming, and now the link to respiratory disease. I have challenged this in public scrutiny and the position of many government authorities is that landfill tax is forcing them to compost. Even energy to waste (EtW) has a far lower greenhouse emissions impact.

Bangor University, CEH and a few other groups are rushing to conduct research into soil applications. Personally, I think these technologies could work if biodigestates are controlled, but the chances are, once the technology reaches poorer parts of the world, that safer practices will be unlikely due to the overriding need to maximise land production for food and crops.

Coming back to carbon. I think you will be surprised of some research in the coming years that will show many tropical soils are up to or around 50% soil carbon, not the 10% that we thought. After slash and burn, it would seem there are incredibly high carbon loads yet to be respired into the atmosphere. Not my research - word on streets. Adding nitrogen seems like a pathway to really hot summers.