Early Oxygen

Cores retrieved from layers of deep-sea rocks that are 3.46 billion years old suggest that oceans contained abundant oxygen and that the atmosphere of the Earth was as rich in oxygen as it is today. The cores were obtained in northwestern Western Australia, and contain evidence that the deep ocean 3.46 billion years ago was so rich in oxygen that oxygen-producing organisms must have been actively producing it. This means that oxygen-producing organisms like cyanobacteria were present much earlier in Earth’s history than previously believed.

Source: [Astrobiology Magazine]

March 28, 2009 / Posted by: Aaron Gronstal

Microbial Populations in Antarctic Permafrost

Members of NAI’s Michigan State University Alumni Team are part of an international team of scientists characterizing the microbial populations in Antarctic permafrost soils. Based on multiple samples, they describe the presence of diverse populations of both aerobic and anaerobic bacteria, cyanobacteria, green algae, yeasts, and fungi. Based on the documented ages of the permafrost regions—perhaps more than 5 million years old—these findings represent the oldest viable microorganisms discovered in permafrost on Earth. Their paper appears in the April issue of Astrobiology.

Source: [Link]

June 5, 2007 / Posted by: Shige Abe

Strategies for Evolutionary Success - Sulfolipids

Researchers from NAI’s University of Rhode Island Team and their colleagues have studied the use of phosphorus vs. sulfur in the membrane lipid sythesis pathways of organisms resident in the ocean’s subtropical gyres. Their data show that the dominant organism in the phytoplankton, a cyanobacterium, has evolved a “sulfur-for-phosphorus” strategy; producing a membrane lipid containing sulfate and sugar instead of phosphate. This adaptation may have been a major event in Earth’s early history when the relative availability of sulfate and phosphate was different than in today’s oceans. Their paper appears in the June 6th issue of PNAS.

Source: [Link]

July 4, 2006 / Posted by: Shige Abe

Earlier Evolution of Oxygenic Photosynthesis - Surviving Snowball Earth

Roger Buick from NAI’s University of Washington Team and his colleagues report in the current issue of Geology their analysis of oil-bearing fluid inclusions in 2.45 billion year old rocks from Canada. They assert that the oil is derived from an overlying formation, becoming trapped in the host rock before 2.2 billion years ago – prior to the Great Oxidation Event. Abundant biomarkers for cyanobacteria and eukaryotes were identified in the study, suggesting that aqueous environments at the time had become sufficiently oxygenated for sterol biosynthesis to occur, and implying that organisms had the ability to survive “snowball Earth”...

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Source: [Link]

June 13, 2006 / Posted by: Shige Abe

Shark Bay Stromatolites Revealed

Members of NAI’s University of Colorado Team published a study of the composition and structure of the Shark Bay stromatolites in this month’s Applied and Environmental Microbiology. Their rRNA studies revealed the most abundant sequences representing novel proteobacteria, with a surprising less than 5% representing cyanobacteria.

Source: [Link]

August 17, 2005 / Posted by: Shige Abe