BREMERHAVEN, Germany, June 30 (UPI) -- Researchers in Germany have revealed the chemical mechanisms that govern the ways microalgae adapt to changing levels of nutritional abundance -- ramping up cell division in boom times and boosting metabolic efficiency during lean times.
The research also shows how microalgae begin to digest bits of themselves during times of extreme scarcity.
The findings, detailed in the journal Frontiers of Marine Science, suggest the molecular switches that trigger changes in metabolic strategy are surprisingly similar for all for living things.
"Like all living things, algae depend on the nutrients phosphorus and nitrogen, which are introduced into coastal areas by rivers -- or in the open ocean -- are carried up from depth by eddies," lead study author Sebastian Rokitta, a biologist at the Alfred Wegener Institute, explained in a news release. "If the surface water is fertilized by such nutrients, a race for the precious elements begins in which the various algae compete for the nutrients."
The race ends when nutrients are exhausted and algae face a new scenario -- a potential period of scarcity.
Until now, scientists thought microalgae and similar microorganisms reacted individually to each nutrient as it declined. This theory closely reflected their method of study -- measuring and monitoring one nutrient at a time. New genomic technology, however, has allowed scientists to take a more detailed and comprehensive look at how microalgae respond to varying starvation conditions.
Microbiologists at AWI used microarrays to analyze the activity 10,000 microalgae genes during different hunger scenarios. Their research showed that the molecule mechanisms for nutrients storage and shifting metabolic strategy are largely the same for all nutrients. The findings also show the molecular mechanisms of metabolism and cell division are closely integrated.
"Apparently, the triggered genetic programs also include molecular sensors that stop the cell division, so to speak, in case of low nutrient levels," explained AWI biologist Bjorn Rost.
Similar division mechanisms have been shown to be disturbed in human cancer cells, where cellular division and proliferation continues uncontrolled.
The team of microbiologists also found that microalgae begins to digest parts of their molecular machinery to ensure their survival as long as possible during periods of scarcity. Researchers say this strategy is underappreciated and likely a large reason why microalgae are so resilient to periods of nutrient scarcity.