The marine parchment tube worm produces a viscous substance when stressed that glows as a result of bioluminescence. New research published in this month's issue of The FASEB Journal proposes that the unique glowing goo could provide a sustainable light source for future technologies.
Those who have been fortunate enough to witness it firsthand will attest to the beauty of bioluminescence, found in all manner of creatures from glow worms to deep-sea jellyfish. Some bioluminescence occurs in short bursts, such as plankton in the ocean who create quite the show when disturbed at night, while others are slower such as that seen in bacteria and mushrooms. For the tube worm, however, the bioluminescence produced in the mucus it secretes has a slow burn effect, giving off a sustained blue glow.
"The light, or bioluminescence, produced by this worm does not appear as flashes, like in most luminous organisms, but as a long-lasting glow," said Evelien De Meulenaere, PhD, a researcher in Dimitri Deheyn's lab at the Scripps Institution of Oceanography, in a statement. "Understanding the mechanisms of this bioluminescence process could inform the design of a light stick that works for several days or, with further optimization, environmentally friendly garden and street lighting."
When investigating the worm's secretions, it was discovered that the bioluminescence wasn’t being powered by the worm’s metabolic pathways but instead that the light-producing slime was somehow powering itself. Analysis of the slime revealed it contained an iron-storage protein called ferritin that increased the luminosity of the slime when more of it was artificially added. The researchers suggest this ferritin could act almost like a battery, storing energy that fuels the blue glow. Further analysis of ferritin showed it contained more iron when exposed to blue light, and that the worm slime would flash blue for some minutes when given the same treatment.
"A light source based on this mechanism could be remotely triggered using blue light to initiate and amplify the process," said De Meulenaere. "Once we understand exactly how light production happens in the natural system, that information could potentially be used to develop a long-lasting light that is also biodegradable and rechargeable."
Researchers suggest the self-sufficient glowing goo could be used as a light-emitting tag for proteins or cells in experiments. Existing fluorescent light alternatives are currently limited by their short glowing time, whereas the worm's slim could last for many days. Beyond acting as a self-powered light source, it’s hoped the worm slime could play a diagnostic role due to its sensitivity to iron. By reacting to the presence or lack thereof of iron, the viscous substance could indicate iron deficiencies or toxicities.