by Brooks Hays
Washington (UPI) Oct 25, 2017
In order to survive, marine microbes living buried beneath seabed sediments must resort to cannibalism, according to a new study.
In an effort to better understand how microorganisms break down carbon trapped in the sediments at the bottom of the ocean, a team of researchers at the Ludwig-Maximilian University of Munich conducted a genetic analysis of the enzymes secreted by resident microbial communities.
Extracellular enzymes are secreted by microbes to accelerate the breakdown of surrounding organic detritus. The byproducts of the breakdown process are reabsorbed as proteins that serve as fuel for the microbes.
Enzymes secreted into the surrounding sediment contain signature strings of amino acids that mark its extracellular destiny. The microbe's secretory mechanism recognizes this signature and allows the enzyme access to the outside world. These RNA fragments can be sequenced in the lab and used to study the microbes that released them.
"Using a novel bioinformatic method, we searched for evolutionarily conserved, and hence functionally important, amino-acid sequence motifs within these recognition sequences," William Orsi, professor of geomicrobiology at LMU, said in a news release. "In this way, we were able, for the first time, not only to use genetic data to deduce enzyme functions, but also to specifically identify those enzymes that are secreted by cells that live in these sediments."
Researchers sequenced the genetic material found in sediments recovered from deep-sea drilling sites situated off the coast of Peru. Some of the sediments were 2.8 million years old.
The researchers' analysis -- detailed this week in the journal Nature Microbiology -- showed different communities of bacteria, archaea and fungi buried in seabed sediments use an array of enzymes to breakdown carbohydrates, lipids and proteins into usable sources of energy.
The enzymes can also breakdown dead cells, allowing microbes to eat their own kind for additional sustenance.
"Many of the enzymes synthesized and secreted by fungal cells specifically attack the cell walls of archaea, while many of the extracellular enzymes released by bacteria can degrade the cell walls of fungi," Orsi said. "In other words, different classes of microbes apparently cannibalize one another's 'carcasses.'"
Marine sediments are the planet's largest carbon reserve. Scientists hope an improved understanding of the microbial communities living in the seabed will help them more accurately model how carbon and other organic molecules are recycled.
Sydney, Australia (SPX) Oct 09, 2017
Science fiction has frequently considered self-replicating robots that travel across space, making copies of themselves as they spread throughout the galaxy. Such devices are formally known as "von Neumann machines" after the Hungarian-born mathematician John von Neumann, who performed theoretical research into their operations. In theory, such devices could gradually explore the entire galaxy o ... read more
Lands Beyond Beyond - extra solar planets - news and science
Life Beyond Earth
|The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - 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. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. 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|