Hungry green algae prefer to eat bacteria alive

New research suggests that the ability of green algae to eat bacteria is more widespread than previously thought, a finding that could be important in environmental and climate science.

Image of Pyramimonas parkeae and a green fluorescence image showing ingested bacteria. Photo: N. Bock & E. Kim

The work, led by scientists at the American Museum of Natural History, Columbia University and the University of Arizona, found that five strains of single-celled green algae consume bacteria when they are "hungry" and only when the bacteria are alive.

"Traditionally, we think of green algae as being purely photosynthetic organisms, producing their food by soaking in sunlight," said Eunsoo Kim at the American Museum of Natural History, one of the study's corresponding authors. "But we've come to understand that there are a number of species of green algae that also can eat bacteria when the conditions are right. And we've found out how finicky they are as eaters."

The researchers conducted feeding experiments with live bacteria that were labeled with a non-toxic fluorescent dye, and they combined the bacteria with five different strains of unicellular green algae for analyses through a flow cytometer, which helps scientists analyze cell properties in solution.

The flow cytometer measured increasing levels of green fluorescence in the algal cells over time, suggesting that the algae were consuming the bacteria. To confirm that ingestion was occurring, the researchers used high-precision microscopy.

In the process, the team discovered two quirks about the finicky eaters: The algal strains they tested ate only live bacteria (dead bacteria were left untouched), and they ate more when the levels of other nutrients were low. These findings have implications for the study of green algae, the scientists said. (National Science Foundation)

YOU MAY ALSO LIKE

Scientists link flower color changes with climate fluctuations

Scientists at Clemson University have linked climate fluctuations over the past one and one-quarter centuries with flower color changes.

Debris piles up in ‘mid-ocean garbage patches’

Millions of tonnes of plastic and other debris released annually from coastal areas are transported by currents to mid-ocean garbage patches, especially in the North and South Pacific Ocean, and (...)

Chip delivers COVID-19 test results on a phone

COVID-19 can be diagnosed in 55 minutes or less with the help of programmed magnetic nanobeads and a diagnostic tool that plugs into an off-the-shelf cellphone, according to Rice University engineers.

World’s Oldest Impact Crater May Not Actually Be A Crater

Meteorites and comets have captured the public imagination for centuries. They inspire awe when we see them shoot across the night sky (...)

Kilauea eruption triggered by pressure built over a decade

2018 eruption of Kilauea volcano was one of the largest volcanic events in Hawaii in 200 years.

Wildfires may have larger effects on cloud formation and climate change than thought

Chemical aging of fire-emitted particles can lead to more intense storms.