by Staff Writers
Bristol UK (SPX) Mar 25, 2016
Researchers have discovered a 'bizarre' microorganism which plays a key role in the food web of Earth's oceans. Researchers from Spain's Institute of Marine Sciences (ICM-CSIC), alongside colleagues at the University of Bristol in the UK, discovered that symbiotic phytoplankton capable of fertilising the ocean with nitrogen 'fertilizer' evolved back in the Cretaceous at a time when the oceans were nutrient deprived.
This study, which used data from the Tara Oceans circumnavigation expedition, is published in Nature Communications. The cyanobacterium which the researchers have discovered is unique because it has no photosynthetic capabilities - a trait commonly associated with these microorganisms. Instead, its sole purpose is to provide nitrogen to a more complex cell host.
This 'slaving event' evolved around 90 million years ago towards the end of the Cretaceous period, when the oceans were starved of nutrients.
While nitrogen is hugely abundant in the atmosphere, most organisms can't breathe nitrogen, instead relying on bacteria to transform atmospheric nitrogen into bioavailable nitrogen - critical for growth and survival in the marine food web.
Marine scientists have known that bioavailable nitrogen is provided by cyanobacteria, but the new findings take this knowledge one step further, by identifying the intimate relationship of this marine nitrogen factory which is formed by a single-celled alga (prymnesiophyte) and the cyanobacterium UCYN-A.
Dr Silvia G. Acinas, from ICM-CSIC in Spain, led the study and said: "This is a very important symbiotic system in marine environments because they are globally distributed, playing a significant role in today's nitrogen and carbon marine cycles."
Dr. Patricia Sanchez-Baracaldo, from the School of Geographical Sciences at the University of Bristol, added: "A stage of scarce nutrients in the ocean could have led to the establishment of the symbiotic relationship between the algae and the cyanobacteria back in the late Cretaceous, after the oceans had been deprived in nutrients."
This research has been made possible thanks to the metagenomes and metatranscriptomes dataset obtained from the Tara Oceans oceanographic expedition.
Research paper: Cyanobacterial symbionts diverged in the late Cretaceous towards lineage-specific nitrogen fixation factories in single-celled phytoplankton Several international laboratories including the University of Bristol (UK), VIB/VUB/KU Leuven (Belgium), Aix-Marseille Universite (France), Centre National de la Recherche Scientifique - CNRS (France), Genoscope (France), European Molecular Biology Laboratory - EMBL (Germany) and the University of California (USA) have participated in this study.
University of Bristol
Explore The Early Earth at TerraDaily.com
|The content herein, unless otherwise known to be public domain, are Copyright 1995-2016 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.|