Tagged: sclerotia

Monday, March 4th 2013

Today we took the sclerotia out of the incubator.  It didn’t look very promising.  Most of it had died and looked infected.  We cut the small area of ‘normal’ looking sclerotia out and kept in in a petri dish in hopes it would dry out completely and be usable in the future.  We also changed the oats in our living culture.


Please see my inquiry partner’s blog entry for more details: http://annicah.inquiryhub.org/2013/03/05/march-4th/


Wednesday, February 27th 2013

Today we worked on our PowerPoint presentation and pretty much finished it.  We also plated petri dishes with nutrient agar and started the sclerotia process again.  We are converting all our cultures except for one (the new one we cultured from our maze experiment) into sclerotia.  The cultures (2 petri dishes of soon to be sclerotia) are now in the incubator and we will need to take them out about 24 hours from now.

Friday, February 15th 2013

The slime mould finished solving the maze last night at around 7:30 pm.  I got a picture of it at 4 pm, then forgot about it until 7:25 pm, when I checked on it and found that it had solved the maze, so I’m not sure exactly when it finished, but it was sometime just before 7:30 – maybe 6:30 or 7:00.

Today we transferred the filter paper from our second sclerotia attempt to an empty petri dish, cutting out sections that had other mould growing on them.  We put that culture back into the incubator (along with the others) to let the filter paper dry out.  We also changed the oats in the other living cultures.

Wednesday, February 13th 2013

Today at 9:24 am we put the slime mould into the maze!  We took a small piece of it with the agar it was on (from one of our first sub-cultures) and placed it upside down at the start of the maze.  We put several oat flakes at the end of the maze.  After watching it and taking photographs periodically every half hour, it didn’t look like it was growing much so we gave it an extra oat flake at 12:50 pm, thinking maybe it didn’t have enough food to be able to get all the way to the finish.  It has grown minimally since this morning (less than a centimeter in the last 5 hours).  Considering the top growing speed we read about online (1-1.8 cm/hr.), we are wondering if a) it didn’t have enough food or b) we didn’t put enough slime mould in to start with.  My partner is planning to take it home and keep photographing it as time progresses.  Hopefully it won’t grow too much during the night.  The maze is quite large in comparison to the organism, so it could take a while.

We have been keeping the rest of the cultures in the incubator as they seem to grow better in there, and have started the process of making sclerotia again with our original culture.  We changed the oat flakes in what was left of the original culture and put it back in the incubator to keep warm.

Tuesday, February 12th 2013

Leaving the cultures for the weekend seems to have been a good idea.  The two that had formed crusty balls in the corners of the petri dishes don’t look any better (worse, if anything – at least one of them is growing another type of mould), but the others have grown and are looking better.  The sclerotia we prepared on Friday (that has been in the incubator all weekend) to transfer back to its growing state has turned out well, except for a bit of contamination from some black mould, which we tried to remove this morning.  We added oat flakes to most of the cultures and put them in the incubator to warm up and hopefully grow better since the room they are in is very cold today.

Friday, February 8th 2013

After discovering that a couple of our cultures didn’t look like they were doing to well this morning, we decided to put off the maze test until Tuesday.  2 of the cultures appear to have retracted their veins and formed small crusty balls near the edges of the petri dishes.  Perhaps the clean-up job we did yesterday was a bit too much for them, but in any case, we want to allow the cultures the weekend to grow and recuperate before putting them into the maze we created.

Today we started the process of reviving some of our sclerotia.  We selected a petri dish prepared with non-nutrient agar, sprinkled a few oat flakes on it, added a piece of dried filter paper containing sclerotia, and applied a drop of water to the filter paper.  We sealed and labelled the petri dish, then covered it in foil to keep it dark.

Thursday, February 7th 2013

A lot has happened since my last entry on January 23rd.

Here’s the rundown:

The incubator we ordered finally arrived on January 25th, and we tested it out for about 20 minutes.

The petri dish we had left out in the science room with only non-nutrient agar as a test culture dried up and resembled a warped sheet of very thin plastic.

On January 28th, we began our sclerotia-making endeavour.  The first step to converting growing plasmodia into its dormant stage (sclerotia) was to put it on nutrient agar and incubate it.  We prepared 6 petri dishes with semi-defined (nutrient) agar, transferring small bits of growing plasmodia onto 4 of them, leaving one out, exposed to the air in the kitchen this time as a test (like we did with the non-nutrient agar), and saving one for future use (and as a test) in our supply cabinet at room temperature.  We exposed the test plate to the kitchen air this time instead of the science room air because we thought the air in the science room may have contributed to drying it out since that room is heated more.  However, the results were the same: the agar dried up and formed a thin sheet of brittle dehydrated agar.

After preparing the petri dishes with the nutrient agar, waiting for them to set-up, lining them with filter paper, transferring the growing plasmodia onto the filter paper, sealing them with electrical tape, labelling them, and covering them with foil (to keep the cultures dark) then re-labelling the foil, we warmed the incubator up and put the petri dishes in.

We left the incubator on all night at its lowest setting (which turned out to be around 26-28 degrees Celsius), then turned it off the next day, waiting to see if the filter paper would dry at room temperature as we read it was supposed to.

Sometime after 24 hours, we opened our incubated cultures and transferred the growing slime mould that was still on its filter paper into new petri dishes that didn’t have any agar in them.  We then put these back into the incubator.

On January 30th, we changed the oats in all of our growing cultures (the ones we were trying to make into sclerotia did not have oats) and looked at the original culture under a microscope.  It looked….yellow.

We also came up with a couple of drafts for a possible maze, and are planning to test our maze-making skills tomorrow when my partner brings in some lego.

On January 30th, our plan for making the maze was to build it on a base piece and stick it directly into a Tupperware container we had previously purchased at the dollar store.  But little did we know that on January 31st we would find out that the container featured an obvious yet hidden divider, making it unsuitable for out plan.  Dunn dunn dunn dunnnn….

As it tuns out, the packaging of the container had conveniently covered the part where your could see the divider, so, upon purchasing the container, we didn’t know it had one.  Therefore, the lego base piece didn’t fit into the container and we were left with another problem to solve.

We continued checking on the filter paper the next day or two to see if it was dry, but ended up finishing the sclerotia-making process shortly after we discovered another type of mould growing in one of the incubated cultures.  Though the filter paper was not completely dry, the slime mould had formed small, dry, crusty clusters that were slightly darker in colour to the growing mould.  We presumed these to be sclerotia.

We cut the filter paper that had the clusters and placed them in two other (plain) petri dishes – one for the transferred pieces that came from the contaminated culture and a separate one for the rest of them (prejudice, I know).  We proceeded to cover these in foil to keep them dark, and they have been sitting undisturbed in the supply cabinet since.

When we transferred the migrating plasmodia that was on the filter paper from nutrient agar to empty petri dishes, we kept the supposedly ‘mould-free’ plates of nutrient agar that we used.  Looking at them now, they are infested with other types of mould, and are quite interesting.  Is that what we’re breathing in the air all the time?  I guess those plates display the difference between non-nutrient and nutrient agar: one is easy to keep unwanted things from growing on (the non-nutrient agar) and the other is not.  Or so it would seem.

It is interesting to note that the petri dish of nutrient agar that we sealed immediately after preparing and have not re-opened since has not grown anything,  So how did the other mould get onto the now slime mould-free plates?  Some things might have to remain a mystery, but they didn’t just appear out of thin air …actually, on second thought, they might have.

On February 4th we attempted to sterilize a few things….first some used petri dishes, then the lego we would use for our maze,  We soon discovered that a) petri dishes cannot withstand boiling water and b) lego doesn’t do much better.  After first trying the petri dishes and ending up with warped tree ornaments, we thought we would be smarter with the lego and try a test piece.  Unfortunately we discovered a little too late that the two-blocks could withstand boiling but the others could not.  Our lego blocks and base piece now not able to be attached together again, not to mention being slightly discoloured, we had to think up another plan of action.

Our new bright idea (let’s hope this one turns out better than the last one) was to get a Tupperware container’s undivided attention (or, rather, just a Tupperware container without any division at all), that would fit the size of the maze, put a layer of non-nutrient agar on the bottom, and stick the lego pieces directly into the agar when it was semi-solidified.  We then embarked on the now somewhat habitual task of melting and pouring the agar.

My partner took care of fixing the lego pieces into place with only minor complications.  The only things that went wrong were a) the agar solidified a little too much before the lego places were placed in it, resulting in small cracks, and b) there was a slight change in formation as far as the shape of the maze (apparently my drawing skills could use some improvement).

With a few re-calculations today (due to the slight change in shape of the maze) on how long the mould would take to solve the maze if it grew at top speed, we came up with an estimated time of maze completion being about 10.2 hours.  However, we are expecting the mould to take longer than that, as that is the top speed we read that slime mould grows (1.8 cm / hour), and another source said only 1 cm / hour.

One of us is planning to take the mould home while it is solving the maze so we know exactly how long it took to solve the maze.

Looking at our original culture we discovered a bit of contamination from some type of black mould.  We removed the chunk that was contaminated and soon discovered that our other cultures were growing out of their petri dishes.  Looks like the taping job we did didn’t quite suffice, and the mould must have been hungry because it was making it’s way down the sides of the petri dishes, probably looking for food.   We washed the lids of the petri dishes, cleaned up the sides and bottoms of the containers, and re-taped them – better than last time.  We also changed the oat flakes that the cultures were eating, giving them fresh ones and trying to put them in the centre this time to encourage the slime mould to grow into the middle of the petri dishes rather than toward the outside.

I think that about sums it up!  Tomorrow we put some mould in the maze and see how it goes!