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[Skautroll]

Bacillus thuringiensis israelensis - work in progress

Short introduction

This soil bacteria is the primary component in commercial pesticides like GnatOff and Gnatrol. It is a remarkable microbe that produce toxins that target flea larva, in particular the pests blackflies and fungus gnats. Once exposed to the toxin the larva's hormone balance is impaired and it stops feeding resulting in death within 24 hours. This bacteria seem to have little impact on other organisms than flea larva, which make it an ecologically friendly option for pest control, particularly indoors.

Bti cultivation experiment

I got the motivation to try cultivating Bti after discussing it in another thread about Psychotria Nexus, after reading a few articles on how to cultivate Bti I decided to give it a go. Since there seem to be several  other members interested in experimenting with this I thought we might as well keep track of any progress in a separate topic.

Substrates

A few suggestions, more on the way

Protein sources
Nutritional yeast
Soy bean flour

Sugars
Malt extract
Potato flour
Corn flour
Glucose syrup
Corn syrup




I'll update with more info links and info later when I get the full version of some research articles..

6 Likes New Wisdom, TBM, happyconcacti, Greentoe, fairdinkumseeds and 1 more people like this.

[SoulGrower]

I use to buy this as 'mosquito dunks' (it kills mosquito larvae too).  I'd break it up and sprinkle it over my bromeliads to control the mosquitos.

Now I get some from a friend that works for the county.  They use it in the broms too.  Theirs has two varieties though (in addition to israelensis).  Apparently some mosquito larvae have become resistant to the israelensis.  I believe it is pulverized corn that they are using for the carrier.. not sure if it is actually acting as a substrate/growth media but guess that would make sense.

I could send you some if you're interested in another variety.  I'll have to find out what the name is.

1 Like Skautroll likes this.

[TBM]

How would you be able to tell if you're growing what you introduced or if you have contamination? I'm assuming you're already planning on pasteurizing/sterilizing your substrates somehow before inoculating.

I'm just curious because depending on the culture it can be difficult to tell if there's contamination, while others it's quite easy (wrong colors, odors, etc.).


Maybe some food sources are more likely to become contaminated than others?

[Skautroll]

You will need to sterilize it first, a pressure cooker is the quickest way to do it. Liquid cultures work the same way either its mushrooms mycelium or bacteria.

Bacteria live by the feast or famine principle, as long as you add enough to a starter culture they will dominate it very quick. In their typical native environment these bacteria can be expected to compete with yeast, lactobacillus and molds since they have defences directed against the insects that spread and feed on these microbes.

You can expect some degree of contaminants, but its easy enough to test your freshly brewed gunk on some decomposing fruit festering with gnat larvas. If they stop feeding you know its on the right track at least

2 Likes TBM and Sunshine like this.

[Skautroll]

I have to say this bacterial culture sure is useful for slow sprouting tropical shrubs seeds like P. viridis, T. Undulata and iboga  To make sure there is no gnat maggots nibbling on the seedling taproots can be frustrating as hell,

[New Wisdom]

I treat my pereskiopsis/epiphytes regularly with it and it's amazng to stop fungus gnat infestations.

1 Like Skautroll likes this.

[happyconcacti]

I left a gallon jar of gnatrol mixture (mixed at heavy ratio) for about two weeks.

When I used it today, I noticed a thin film had formed over the top. I didn't know it was there until I dipped a cup into and that's why it's not perfectly skinned over the top in the picture below

Could this be something that could be used for a starter culture like making kombucha?

1 Like fairdinkumseeds likes this.

[New Wisdom]

I'm pretty sure that the starting culture is a specific type of bacteria and yeast rather than just anything.  I personally wouldn't use that for kombucha since it could contain something dangerous. I don't really know for sure though.

I've left out jugs of gnatrol before (accidentally) and they ended up just stinking horribly like rotten flesh.  So i think it all just died and then rotted after a while.   

Also, The bacteria used in gnatrol is suseptible to light (according to the directions on my container.) Meaning that it will die in contact with light for a period of time. That's why it reccomends that you apply it at dawn.  This way it has time to sink into the soil and establish before the sun comes up. Kind of like trichoderma.

[happyconcacti]

ah, gotcha, didn't know about the light sensitivity.

Definitely wasn't suggesting making Kombucha from gnatroll, but a similar process: where you start a new culture with an old SCOBY.

Hcc

[New Wisdom]

Oh I see what you mean.  That would be awesome if it worked out like that.  Do you think that culture on the top is the thuringiensis israelensis?