Forgotten nematode experiment

Rummaging through boxes in my studio i found a lunch box containing the nematode culture my sister gave me for Christmas. It was an unusual present – a tub of yellowish slime smelling of vinegar. These nematodes feed on yeast. The growth medium is porridge oats and a bit of yeast to get it going.

The microscopic worms form tree like patterns as they creep up the sides of the container; writhing masses of worms form super highways; (branches) either to escape the saturated lower regions of the culture or in seeking of new food – i dont know yet. these branchlets seem to persist for quite a while.

I mixed up 3 cultures to with varying amounts of oats and yeast and water unfortunately i lost my notes and forgot about this since Christmas. I was pleasantly surprised to see that they were still fermenting & wriggling away in this tub with excellent results…

The original Tub showed stubby branches which did not go very high in the container. (originally these branches spread all over the inner surfaces) worms were still invisible.

Tub A and C pictured below..
Nematodes form into evenly spaces spots, clusters of tiny worms, around the inner surface. The worms are less than 1mm long but fairly active – in tub C the worms are inactive and form faint irregular branchings

Tub B
Had very active complex branchings, and the worms had grown to about 2mm!
There is an interesting dynamic with the movement.

In the film (which was made in a bit of a rush) you will notice that when the worm moves across free space & meets another worm they move against each other the seem temporarily magnetize to each other & sometimes to deflect trajectories. This has to be partly to do with capillary build up of liquids around the worms bodies. Perhaps it is easier to collectively amass to hold fluid together, perhaps making it easier to move and feed. I plan to do some time lapse of this…

Slime mold escapes

Simon Parks a microbiologist at University of Surrey, & represents & a “collective” of artists working with slime molds called the Physarum Dynamic. see http://www.unnecessaryresearch.org/

He sent me these amazing images of slime molds creeping over a book. apparently a laboratory accident of some kind – these molds try to escape the confines of the petri dishes given the chance. I would not like to fall asleep near one.

He as well as other members of the institute of unnecessary research have been keeping these as pets.
Simon also works with these ‘bio-fluids’ bacterium which appear to behave like fluids, rather than typical bacterial cultures which tend to propagate in circular growths. I am still not clear on the mechanism of this phenomena, But here is Simon’s take on it;

“This type of bacterium grows as a long chain of many thousands of individual rod-like cells. The chain is extended by the growth of individual bacteria within the chain and these generate a pushing motion. Single chains of bacteria, join together to form threads and the pulsing power is amplified. I think this is how the waves are generated with whole masses of bacterial threads uniting to become a wave that flows around objects and becomes turbulent”

In this image the growth filaments or strands seem to be encircling this opening in the medium; the circular hole that was cut in the agar gel – this looks as if it were liquid pouring through a hole. It would appear that the bacterium obeys the laws of fluid mechanics.

Non-living Dissipative Systems

Its too late at night to be writing anything meaningful about slime molds, I have read that its is quite common to find it in the woods Looking at this site I think I may have actually seen some. This bears some relevance the the BZ reaction we have been working on…

“The investigation of such self-organizing chemical systems is still going on. All these chemical systems, mainly variants of the BZ-reaction, strongly point in the direction of corresponding biochemical processes in Organisms, for example the aggregation patterns of the Slime Mold. This mold consists of amoebae (unicellular animals) living on the forest floor. When starved (i.e. finding themselves in unfavorable conditions) they aggregate into a multicellular body which can then move in search of a more favorable habitat. The aggregation is triggered by the release of the compound cyclic adenosine monophosphate (cAMP) from some of the amoebae”

http://waynesword.palomar.edu/slime1.htm /a>

Spiral waves in colonies of the mold Dictyostelium discoideum. These patterns are created when the mold forms aggregates in response to some external ‘ stress’, such as a lack of moisture or nutrients.