For Christmas, a bacterial love story: The Incredible Journey

Figure 1. The Cyanophyte Oscillatoria animalis growing on agar (left) and viewed under a low-power  microscope (right)

I’m exploring the use of the photosynthetic and auxotrophic Cyanophyte (Cyanobacterium) Oscillatoria animalis  (Fig. 1) as novel BioMaterial that can be fashioned from little more that sunlight, water and air.

When this filamentous bacterium grows in shallow culture media it self-organises into a floating bladders (Fig.2) that are reminiscent of silk moth cocoons. In fact, the bladders here are also woven from millions of microscopic filaments.

Figure 2. Floating bladders of Oscillatoria animalis, each one is woven  millions of microscopic filaments

I discovered the remarkable properties of the structures formed by Oscillatoria  when I accidentally knocked a cultured onto the floor. Fortunately, the bottle was plastic and so didn’t break, but my Oscillatoria structure that had taken 3 weeks to grow  had turned into a green soup. However, when I returned from a coffee break about 15 minutes later the Cyanophyte structure had miraculously repaired itself. The video below is a recreation of the accident, but here I deliberately shook the culture. The time-lapse represents 10 minutes of real time

 

Now to the love story. To grow the Oscillatoria structures, I clone them, that is I cut them into two, and transfer each cut-half into a new culture dish, where they grow into larger bladders again. The process is then repeated again and again. On one occasion that I did this I’d run out of fresh media so I left the two freshly separated halves to separate and float apart across the distance of the Petri dish. The uncut Oscillatoria bladder can be seen in Fig 3. below.

One

Figure 3.The uncut Oscillatoria bladder

The image (Fig 4) below shows the cut bladder and freshly separated halves.

Two

Figure 4. The two newly split daughter forms of the Oscillatoria bladder

 

Now this is where the love story really begins. When I returned the lab, the following morning, after having cruelly separated a union, the two halves had reached out to touch each other across the distance of the culture dish (Fig 5). For the microscopic cells of Oscillatoria,  the distance over which this re-uniting grasp occurred, must be the equivalent of  reaching out over massive planetary  distances for us. You can see this first recontact in the image below (Fig 5)

three

Figure 5. Reconnection of the two Oscillatoria  forms across 10 cm of liquid culture

 

Over the next few days and in the images that follow  (Figs 6-9), the two separated halve slowly pulled each other until over vast distance for them, they were finally reunited.

four

Figure 6 . The two Oscillatoria forms slowly pulling themselves together fivesix

Figures 8-9. The two Oscillatoria forms slowly pulling themselves together

seven

Figure 9: Finally the two Oscillatoria structures fuse and reunite having once been separated by vast distances. The end of an Incredible Bacterial Journey 

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