59 replies to this topic

[MichiganAnts]

why not throw them in the cold and then move then ants to a temp sterile environment. then scrub out that mold?

[benjiwuf]

Actually, you only need 100 c (roughly 230 f) for 30 minutes done twice to completely sterilise anything (learned from uht processes with normal everyday use tanks and lines). We also use ethanol to sterilise our gloves before adding cultures to yogurt (which I can only assume helps eliminate any microbiological agents on them).
Although h2o2 works as well and is used in the food industry in conjunction with heat sterilisation.

Edited by benjiwuf, October 10 2016 - 6:53 PM.

[drtrmiller]

100 C isn't even sufficient to sterilize all Bacillus spores. Then, there are thermophiles that can survive even higher temperatures. Holding temperature is process dependent, and that which is required to safely manufacture yogurt may be different from sterilizing a highly contaminated, porous plaster material.

Ethanol, water, and acetone are examples of polar solvents. They're great for rinsing, or in the case of high proof alcohol, preventing microbiological growth by restricting access to water. Ethanol would be a better rinse than distilled water, because it may also kill any living hydrated organisms on the gloves, in addition to rinsing spores off.

Edited by drtrmiller, October 10 2016 - 7:06 PM.

[benjiwuf]

100 c sufficiently kills all microbiology for uht milk for the tanks and lines only (as I do this daily for work). 140 c for 4 seconds for the actual liquid milk is required for uht processes. You can achieve the same result with a cooler temp but longer time (as described in food manufacturing for different products. My specific example is any Pasteurised Milk Ordinance you can find. It describes the minimum Temperatures needed to kill at least bacteria which is much much colder. As for mold, it is sufficient with 100 c I guarantee it. If not then we would be using higher temperatures in the process as our yogurts must also be treated as sterile products to achieve maximum shelf life). However since yogurt is a high moisture low acidity product, mold is of great concern.

Edit: ok yes there are thermophillic molds, but typically they do not live at our lower temperatures. The porous surface is also problematic, but you just need to ensure you have complete penetration for 30 minutes.

Edited by benjiwuf, October 10 2016 - 8:39 PM.

[Reacker]

everything in this thread*

 

[Citation Needed]

[PogoQueen]

Hello this is Andrews microbiology friend! In my Medical Mycology class in college we used Lysol and 70% ethanol to sterilize our work areas and any mold growth in our Petri dishes. When I worked as a microbiologist after college we used 70% isopropyl alcohol and a bacdown solution to sterilize our work areas. We switched every month to make sure the bacteria and mold did not develop a resistance to either sterilizing solution. I agree with Benjiwuf when he says you can sterilize by boiling in 100c water for 30 minutes. I've worked with listeria, salmonella, aspergillus and everything in between in the lab and we used the isopropyl alcohol for all. The important thing to remember with alcohol is concentration. Too dilute and it won't kill and too concentrated and it will only damage the surface and will not penetrate deep enough to kill. Alcohol works by denaturing the proteins, not by drying out the cell. A simple Google search using "alcohol denaturing proteins" will explain it better than I can on exactly how it works. If I were you I would sterilize by boiling! Although the alcohol should work and not kill your ants if you rinse it thoroughly afterwards and give the alcohol enough time to evaporate. My citation is my experience and degree, but you can also do some light reading from the cdc website:

https://www.cdc.gov/...sinfection.html

Or on alcohol denaturing proteins:
http://chemistry.elm...naturation.html

Good luck! I hope you solve your mold problem.

Edited by PogoQueen, October 10 2016 - 8:01 PM.

[benjiwuf]

I also can't stress enough, you do still need to clean the surfaces. Sterilisation only works when it can penetration, and any biofilm or residue will decrease the effectiveness of any sterilising agent you decide to use. Peracetic acid also is another chemical option (adding to the list of several alcohol types, and H2O2). My citation would also be my last 4 years of work experience with sterile food manufacturing with not only yogurt, but shelf stable uncooled Ultra High Temperature Pasteurised Milk (in which everything must be completely sterile to achieve).

[drtrmiller]

I can't believe I'm having to point this out. The conflict in advice here has to do with an ambivalence on the distinction between disinfection and sterilization, two completely different terms.

To be clear, sterilization with an emphasis on sporicidal action is required, not simple disinfection procedures, because the gypsum formicarium media is porous, and surviving spores will readily germinate once the disinfectant is rinsed or removed. Even CDC per your resource acknowledges alcohol is not to be used for sterilization, only disinfectant.

Edited by drtrmiller, October 10 2016 - 9:22 PM.

[dspdrew]

Even CDC per your resource acknowledges alcohol is not too be used for sterilization, only disinfectant.

 

I could have sworn alcohol is used for sterilization all the time. Where does the CDC's website acknowledge that alcohol is not too be used for sterilization?

[drtrmiller]

"Uses. Alcohols are not recommended for sterilizing medical and surgical materials principally because they lack sporicidal action and they cannot penetrate protein-rich materials."

[benjiwuf]

Well, i can honestly tell you that if 100c was not sufficient to sterilise then all yogurt would be moldy before anyone purchased it. Along with uht milk not being shelf stable since it contains protein, fat, and sugar. Couple that with quite a bit of water and stagnant air, and you have a perfect medium for mold growth.

[drtrmiller]

Benji, you keep referring to ultra high temperature (UHT) sterilization, but you keep saying 100 C. The procedure isn't relevant here since that occurs in specialized machines. But can you link to a resource that supports those figures?

[benjiwuf]

It is relevant as it has to be completely sterile (bacteria, mold, and yeast must be completely killed). The 140 c is only necessary for 4 seconds, 100 c for 30 minutes and continues on a curve (so if you want to go to 140, by the time you get there you're already sterile since its difficult to reach at home). You yourself said 140 c was necessary and 100 c is too cold, that is not correct. I mention for the point of fact that it can mold easy and i have direct daily experience with it. When I get home I'll check for a curve link, or you can lookup the PMO as I described above as it should be in there. I've also checked with the Molkerei Meisters here as they've spent 4 years learning exactly this material, and they've said the exact same thing.

Edit: when sterilising against mold you also have to use a moist medium like steam or water.

Edited by benjiwuf, October 11 2016 - 12:26 AM.

[AntsMAN]

I'm really tired of people guessing at what kills mold. Here are the facts:

Fungi thrive in acidic environments. Vinegar, a weak (acetic) acid, will not kill fungal spores, but will suppress growth temporarily, until it all evaporates away.

Alcohol, again, has a drying effect on the fungus itself, but will not kill the spores, only keep them from germinating, until it evaporates away.

For hard, non-absorbent surfaces, only hydrogen peroxide or a strong, oxidizing base like sodium hypochlorite (aka bleach) will actually kill the fungal spores. Unfortunately with any plaster or grout formicarium, the molecules are too big to fully penetrate the medium. Still, it is the best option, short of dry heat.

Dry air hearing over 140 C (285 F) for 3 hours will guarantee complete sterilization. This is only possible with glass and heat-resistant materials, however.

 

Thanks, for the awesome advice everyone. Getting some bleach and hydrogen peroxide today and for the nest with the mold sandwiched underneath, I'm going to remove the material in that area and clean thoroughly.

I'd bake (285 F) them but I don't think THA materials are heat resistant.

 

As for the ants they are 80% dead now, the queen is still kicking and the brood seems fine, but the workers are steadily dying.

I'd move them one by one but I can't get to them in the nest. I've tried everything to get them to move.

[benjiwuf]

I have a book all about proper sterilization methods and procedures. I can't link it as it is a paid book. "Handbuch der Milch und Molkereitechnik" for those that feel like delving into the German and EU regulations written in German (Dairy processing handbook {for the more detailed version you must buy it, however here is an extremely simplified version that requires only an email address and name http://www.dairyproc.../long-life-milk which was provided through a Tetrapak website } which can be found for a price from Tetrapak which is a rather large food and drug manufacturing and engineering company). Otherwise i found relatively little in my searches of the government websites. Should you like to see the handbook i'll have to photograph it, which reduces the credibility....and it'll only be in German. However in there you will find a curve, 121 C is recommended, but only for 3 minutes. 140 C for mere seconds, and 100 C for a half an hour. The reason that the milk reference is quite relevant also is that mold does not typically grow on high sugar content food products due to low available water values. Milk on the other hand is quite  susceptible to mold since it has a high available water value, protein, and typically remains stagnant. UHT milk is more susceptible than normal products also as it typically remains uncooled (providing a perfect temperature for mold growth along with a good medium to grow in).

[drtrmiller]

I'll keep all this in mind for my future dairy-based formicarium. Thanks!

[benjiwuf]

can't wait to try it out!

[Subverted]

Definitely worth pointing out that there is close to zero comparison between processes used to sterilize surfaces/materials and processes used on liquids. Completely different problems.

For porous surfaces things are even more complicated. Whatever method you try, please do it twice. That should get any left over spores that might have survived and then tried germinating.

[drtrmiller]

That's one way to know whether hydrogen peroxide is working. Soak 24 hours, fully submerged in H2O2. Allow to air dry fully. If a second application yields lots of bubbles, then it means there's still something, probably an organism, to which the H2O2 is reacting. If there are no bubbles, then you've probably killed most of everything (at least as far as the liquid can penetrate into the material). Should be rinsed with distilled water and fully air dried before further use.

Edited by drtrmiller, October 11 2016 - 11:37 AM.

[JasonD]

That's one way to know whether hydrogen peroxide is working. Soak 24 hours, fully submerged in H2O2. Allow to air dry fully. If a second application yields lots of bubbles, then it means there's still something, probably an organism, to which the H2O2 is reacting. If there are no bubbles, then you've probably killed most of everything (at least as far as the liquid can penetrate into the material). Should be rinsed with distilled water and fully air dried before further use.

 

Just chiming in here, make sure you do this in a cool dark environment! Hydrogen peroxide is extremely light sensitive, especially when diluted. If you let a bucket of this stuff sit outside you'll lose a ton of effectiveness, and you'll see bubbles as the H2O2 breaks down to water and oxygen as it's hit by light.