Novel study published in Science sheds light on microbial ecology, energy and nutrient cycling in the sea
SUNNYVALE, CA, 14 September 2000 - Using the same DNA sequencing technology that played a key role in decoding the human genome, scientists have discovered a new type of light-activated protein in surface water bacteria that may represent a new mechanism for cycling carbon in the oceans and utilizing sunlight for food production. The study, conducted by researchers from Amersham Pharmacia Biotech and Monterey Bay Aquarium Research Institute in Moss Landing, CA, is published in the September 15, 2000 issue of Science.
The protein, called a "proteorhodopsin," was discovered through genomic analyses of bacteria found in plankton taken from surface waters in Monterey Bay. Unlike most studies of microbial genomes, DNA samples were taken directly from the bacteria instead of being isolated and cultured in a laboratory. The microbial DNA was isolated from the seawater samples and sequenced using Amersham Pharmacia Biotech's MegaBACE 1000 high-throughput instruments and DNA sequencing reagents at the company's Production Sequencing Laboratory in Sunnyvale.
Through genomic analyses, the researchers determined that when exposed to light, the protein pumps ions across the cell membrane, the basic mechanism for generating energy for all life. The study challenges the long-held presumption that most planktonic bacteria live like humans, by eating energy-rich organic compounds. The discovery of this new photoprotein shows that these marine microbes, which are abundant in surface seawater, most likely subsist by using light energy.
"This type of information is valuable because it tells us what these organisms might be doing out in the ocean and how they are making a living out there," said Dr. Robert A. Feldman, Production Sequencing and Collaborations Manager for Amersham Pharmacia Biotech. "The study highlights our ignorance of oceanic microbes and shows how the application of modern biotechnology and genomics techniques to global marine ecology questions will fundamentally change our understanding of marine biology."
"Our approach marries ecological and environmental science with modern genomic technologies," said Edward DeLong, lead scientist on the study and microbiologist at the Monterey Bay Aquarium Research Institute. "For the first time, we have access to the genomes of abundant and ecologically relevant microbes, even though we cannot grow them. It is functional genomics, moving outside the laboratory."
The study is the latest result of a valuable sequencing project completed by Amersham Pharmacia Biotech for the Monterey Bay Aquarium Research Institute. Some of the data analysis and experiments were also conducted by researchers from the National Institutes of Health and the University of Texas Medical School.
Amersham Pharmacia Biotech is at the frontier of new healthcare, providing technologies to discover, develop and deliver therapies faster and more cost-effectively than ever before. The life sciences division of Nycomed Amersham plc (NYSE: NYE; LSE: NAM) is an international leader in most of its markets. The customer base for Amersham Pharmacia Biotech's products and technology are pharmaceutical and biotechnology companies and leading research and academic institutions in the United States, Europe, Latin America and Asia. For more information about Amersham Pharmacia Biotech, please visit our web site at http://www.apbiotech.com.
Journal
Science