Mon 29 Jan 18
New research has uncovered fresh insight into how diatoms - microalgae that produce the oxygen for every fifth breath we take - survive in the harsh environment of polar sea ice.
Most diatoms produce a sticky, slimy substance called EPS (extracellular polymeric substances) which protects them from changes in the environment. A new study led jointly between the University of Essex and the University of East Anglia is a world first in showing how this slime is produced by a key polar diatom species for which the genome sequence recently became available.
Diatoms are found in nearly all marine and freshwater habitats and are important to the world’s eco-system as they are responsible for 20% of the world’s photosynthesis – the process by which organisms harvest energy from the sun – and play a key role in the ecology of sea ice. Global warming is resulting in major changes in the amount of sea ice present in the Arctic and Southern Oceans.
The research, funded by the Natural Environment Research Council (NERC), and also involving Bangor University, focused on sea ice as it changes its dynamics, melting and freezing depending on the seasons. The study involved simulating sea ice in the lab with different temperatures and salt content and observing how the chemistry, biology and genetic programming changed. The laboratory results were then compared with material from the Antarctic.
Published in the leading ISME Journal, the study, led by Professor Graham Underwood at Essex and Professor Thomas Mock from the University of East Anglia, focused on the polar diatom Fragilariopsis cylindrus, which is able to thrive under the harsh conditions of sea ice.