An investigation of the genome and phenome of a green alga called Chloroidium sp. UTEX 3007 has revealed, for the first time, certain adaptive traits that help algae acclimate to desert environments.
But what sets apart this new species, which scientists at the New York University Abu Dhabi (NYUAD) have discovered and sequenced, from other types of green algae?
Nature Middle East talks to Kourosh Salehi-Ashtiani, associate professor of biology and managing director at the Center for Genomics and Systems Biology at NYUAD, to find out.
Nature Middle East: What does your new study add to the body of knowledge that we have of green microalgae?
Kourosh Salehi-Ashtiani: Green microalgae or Chlorophyta live in myriad forms and are believed to be the progenitors of land plants. Many scientists around the globe are involved in active research programs to understand the ecological roles of these organisms as well as to utilize them for biotechnology. Despite the importance of micro-algae, relatively few species have been profiled at the genomic and phenomic levels.
These species are mostly from temperate zones, with very little information available on any alga from the subtropical geographies, such as the environment of the United Arab Emirates (UAE). Our study, however, sets a new standard for understanding the biology of micro-algae, and how Chloroidium has evolved to cope with the environmental challenges unique to the region.
NME: Was there anything particularly surprising about Chloroidium?
KSA: Yes. Its ability to thrive on both freshwater and high-salinity growth media and its ability to assimilate an array of uncommon carbon compounds for heterotrophic growth [which is growth through an energy pathway in which an organism that cannot manufacture its own food uses sunlight or inorganic compounds to produce carbohydrates, proteins and fats from carbon dioxide, in order to survive].
NME: Can you tell me more about your comparative study of Chloroidium and land plants?
KSA: Our phenomic and genomic data suggests that Chloroidium has a close relationship with higher plants and may live an intermittent epiphytic lifestyle, in other words, it may live on the surface of plants when such an opportunity arises. We show the Chloroidium is able to uptake many different sugars. Now, if you think where an alga is likely to find sources of sugar, plant and plant material become the most obvious candidates.
NME: In your paper you mention that Chloroidium harbors “unique protein families involved in osmotic stress tolerance and saccharide metabolism,” would you mind explaining this to our readers?
KSA: It is known that many organisms, when faced with increased osmolarity or typically high salt concentrations, they start to accumulate sugars internally. The Chloroidium’s genome contains unique genes implicated in the accumulation and breakdown of uncommon sugars. It hasn’t been previously known how organisms accumulate and break down these sugars; our study clarifies this.
NME: What are some of the future applications of your findings now that we have this new species, with a robust and flexible biology, especially with regards to conservation and understanding the effects of climate change?
KSA: In light of the environmental hazards befalling much of Southeast Asia that have been caused, at least partly, by razing high-biodiversity rainforests to cultivate oil palm, we chose to particularly emphasize Chloroidium’s ability to accumulate palm-like oil. The fatty acid profiles of oil palm or Elaies guiensis and Chloroidium are virtually identical.
NME: So this discovery may, in the future, help in providing an alternative to palm oil?
KSA: Definitely. Cultivation of oil palm has been associated with deforestation, if not devastation of rainforests in Southeast Asia. It’s why many European countries are banning the use of oil palm in their products. We think this alga may provide an environmentally-friendly alternative to cultivation of oil palms once further developed.