Starting from spores - todays trials

[ian]

Another trial run. I've 'built' an 'incubator' - a 1960's paper says warmth is crucial so I've put an aquarium heater in a tank of water inside a large tub, it's set to 28C.

I'm trying many methods at once - getting from spores to plasmodia is the major bottleneck in actually breeding physarum and I'm trying to hit on a low tech method that's not too slow.

Germinating spores - Big thing here - Fresh spores will not hatch! They're dormant. They need a few weeks ( about 3 ) of being.

Spores hatch into the haploid phase - the single celled amoeba, they'll hatch in 24-48 hours in water but they need feeding. Low tech solution - one oat per ml of water generates shedloads of bacteria in about 24 hours I use half a sporocarp per ml of water-oats and get swarmer cells and amoeba in a couple of days.

Getting amoeba to mate - even in labs this can be a little hit and miss. High concentrations of cells and a dwindling food supply are triggers, presence of amino benzoic acids helps. That's a nutrient found in mushrooms ( among other things ) so half of my plates today are made with mushroom extract ( 10g mushroom chopped in 100ml water, boiled and strained )

Rotting paper method- so far I've found this infallible ( over 15 trys ) but sloooooowwwwwww - Piece of filter paper in a honey tub, wet it, add amoebae and a couple of oats. Leave in a drawer and check weekly. After a month add more water and maybe more oats. In amongst the piles of mould and stink, new plasmodia will appear but it takes 2-3 months. I've set up six tubs, half without additional oats, some with mushroom exract.

Agar - this should, I've dabbled and it's been unreliable ( but successful ) - but I didn't know about the heat. In lab methods they get plated on to plain agar with killed ( formalin fixed and washed ) E. coli - which fulfills the dwindling food supply side - it;s possible to get results in a week.

I'm trying - just plate on 2% agar and plating on mushroom extract agar - 3 drops of culture on a 35mm petri dish. Plates of single parent and mixed parent cultures - eighteen plates in total.

'Back to nature' approach. Hey these things live outdoors, so what the hell - Ive put a handful of fallen, wet and trodden beech leaves in a tub with half a ml of mix culture, given it a shake..

I'll check them in a few days

[RyChu]

Nice! Any advice for building an actual incubator for experimental purposes?

[ian]

Yeh - the tank heater isn't great - it's keeping the tub over 20c but not the 28 of wanted - also unlike the aquarium, a tub of still water with a heater in it stinks very quickly. I've a reptile heating cable and thermostat that's going to get pressed into service,