Algae are simple organisms, but scientists continue to uncover remarkable characteristics that prove beneficial for humans as well.
Michigan State University researchers discovered that some algae can protect themselves when the oxygen they produce harms their ability to conduct photosynthesis. This helps to solve a decades-old mystery about how algae live in conditions with low carbon dioxide, the gas they consume during photosynthesis.
This research also could lead to methods for boosting biofuels production, considering algae increasingly are used as a biofuel feedstock.
Like plants, algae use solar energy to perform photosynthesis. During the process, they take in CO2 to make their own food and then give off oxygen.
But oxygen can impair some of the key reactions that occur during photosynthesis. An accumulation of oxygen causes hyperoxia, or oxygen toxicity.
When the amount of algae growth increases, so does the amount of oxygen produced. This is a problem when algae are grown at a large scale in dense ponds for bioenergy.
“The overall goal was to understand how algae respond to hyperoxia, as a first step to making bioenergy strains that are more tolerant to such stresses and thus more productive,” Peter Neofotis, MSU postdoctoral researcher, said in a news release.
Researchers examined the ability of different strains of the same algae species to survive at high oxygen levels. They mated some strains to see how offspring respond.
When algae cells respond to low CO2 levels, they activate a biological process that pumps in more CO2. To do this, the cells need to make a special structure, a pyrenoid, to hold the pumped-in CO2.
The MSU team discovered that the pyrenoid serves a double purpose and also protects against oxygen. They figured out a “signal” that triggers algae to make the pyrenoid.
“It’s been a big mystery as to how the algae know it’s time to make the pyrenoid,” said MSU professor David Kramer. “Now that we know a signal, we can potentially get the cells to make pyrenoids whenever we want. This could prepare them to work better during biofuel production.”
The researchers say a lot of the mechanisms are still unclear and more work is necessary to fully understand the genes and processes involved. This study gives a better understanding not only of the specific operating mechanisms within algae, but also how photosynthesis works in general.
One potential application for their discovery could be to introduce the algae’s mechanism into land crops to improve photosynthesis efficiency and boost crop production. Additional research also will help to create algae that are well-suited for the conditions in biofuel generation facilities.