Using microfluidic technology, a team of researchers, led by Justin Seymour of the Massachusetts Institute of Technology, USA, recorded microbes swimming towards dimethylsulfoniopropionate (DMSP) as it was released into channels occupied by the microbes.

DMSP provides underwater and atmospheric foraging cues for several species of marine invertebrates, fish, birds, and mammals and the DMSP injection mimicked the bursting of an algal cell after viral infection. The microbes’ reaction was recorded using a camera attached to a microscope.

The researchers found that some microbes are attracted to DMSP because they feed on it, whereas others are drawn to it because it signals the presence of prey. Actively moving towards the DMSP indicates that the microbes play a role in ocean sulfur and carbon cycles, consuming DMSP or converting it to dimethylsulfide, fundamental to cloud formation.

• Chemoattraction to Dimethylsulfoniopropionate Throughout the Marine Microbial Food Web
  J. R. Seymour, R. Simó, T. Ahmed, R. Stocker,
  Science 2010, 329 (5989), 342 – 345.
  DOI: 10.1126/science.1188418