- 3190 - - MICROBES - on Earth and the planets? Soil is mostly microorganisms, both alive and dead. It is typical to see several hundred different types of fungi and bacteria in a single pinch of soil off the ground, making it one of the most diverse ecosystems that exist.
- --------------------------- 3190 - MICROBES - on Earth and the planets?
- Though it might seem that the dirt under your feet is dead and dormant, the soil under our feet is actually very much alive. It's filled with countless microorganisms actively breaking down organic matter, like fallen leaves and plants, and performing a host of other functions that maintain the natural balance of carbon and nutrients stored in the ground beneath us.
-
- There's still so much unknown about soil organisms. Having that knowledge about these organisms, too small to see with the naked eye, is key to better understanding the soil “micro biome“, which is made up of the communities of different microbes that live together.
-
- If we know where organisms are on earth, and we know how they change through space and time due to different environmental forces, and something about what different species are doing, then we can much better predict how the function of these communities will change in terms of carbon and nutrient cycling having huge implications for agriculture, climate change, and public health.
-
- The ability to accurately predict which microbes would likely be found in a given soil sample increased as the researchers looked at organism groupings higher up on the phylogenetic scale, a system that classifies organisms based on evolutionary relatedness.
-
- On the smallest end of the scale, a "species" represents the finest level of classification; on the other end, a "phylum" makes up the largest and most diverse groupings of organisms. They were surprised to find that they were better able to predict the presence of a whole phylum, as opposed to individual species.
-
- Building a framework for forecasting the soil microbiome at sites across the US will improve our understanding of seasonal and inter-annual change. This could help us anticipate how climate change could affect microbial processes like decomposition or nitrogen cycling.
-
- The more we learn, the more we realize how important soil microbes are for agriculture, public health, and climate change. We know certain factors, like temperature and moisture, affect microbial communities. But we don't know how important those factors are compared to natural variability, or interactions between microbes.
-
- Going from dirt to ice in other parts of the world get even more interesting.
Using years' worth of data collected from ice-covered habitats all over the world scientists have discovered new insights into the processes that support microbial life underneath ice sheets and glaciers, and the role those organisms play in perpetuating life through ice ages and in seemingly inhospitable environments on other planets.
-
- The study examines the ways water and microbes interact with the bedrock beneath glaciers, using samples of sediment taken from glacial sites in Canada and Iceland. We kept finding organisms in these systems that were supported by hydrogen gas. It initially didn't make sense, because we couldn't figure out where that hydrogen gas was coming from under these glaciers.
-
- Through a series of physical and chemical processes, hydrogen gas is produced as the silica-rich bedrock underneath glaciers is ground into tiny mineral particles by the weight of the ice on top of it. When those mineral particles combine with glacial meltwater, they let off hydrogen.
-
- Microbial communities under the glaciers could combine that hydrogen gas with carbon dioxide to generate more organic matter, called “biomass“, through a process called “chemosynthesis“. Chemosynthesis is similar to how plants generate biomass from carbon dioxide through “photosynthesis“, although chemosynthesis does not require sunlight.
-
- Sediment from the glaciers in Canada and Iceland were used to grow the living organisms then watching them over several months to see if they would continue to grow in the simulated environment.
-
- The organisms rely on hydrogen gas as food to grow, and most are also “anaerobes“, meaning oxygen will kill them.
-
- Samples taken from the Kötlujökull Glacier in Iceland, which sits atop basaltic bedrock, produced much more hydrogen gas than the samples from Robertson Glacier in Alberta, Canada, which has carbonate bedrock beneath it.
-
- As they use that hydrogen gas to generate energy, the microbes also pull carbon dioxide out of the air to create biomass, replicate and grow. That ability to "fix" carbon is a critical climate regulation process, another similarity to photosynthesis in plants.
-
- Considering that glaciers and ice sheets cover about 10% of the Earth's landmass today, and a much larger fraction at times in the planet's past, microbial activities such as the ones measured are likely to have had a major impact on Earth's climate, both today and in the past.
-
- We've known for a while that microorganisms living beneath ice sheets or glaciers can fix carbon, but we never really understood how. Not only are these organisms completely self-sustainable in the sense that they can generate their own fixed carbon, they also don't need sunlight to do it like the rest of the biosphere that we're familiar with.
-
- Looking further afield at the other planets in our solar system, two of the critical elements scientists look for when evaluating habitability are water and a source of energy.
-
- The newfound knowledge that self-sustaining microbial communities can flourish in icy environments through the generation of hydrogen gas is a critical step toward identifying potentially habitable environments on other planets.
-
- There's lots of evidence for ice and glaciers on other planets. Are they habitable? We don't know. Could there be microbes living under ice sheets on planets with bedrock? Absolutely. There's no reason to think otherwise.
-
--------------------------- Other reviews available:
-
- 2442 - MICROBES - the simplest life on Earth? The complexity life is not just with us humans. Many other life forms from the octopus to the microbes show us adaptation far beyond our imagination. But, we are learning more. And, not just for our planet only.
-
- 1374 - Microbes, dominant life on Earth.
-
- 787 - Microbes include bacteria, fungi archaea, protists but not viruses and prions which are considered as non-living. The human gut is 20 feet long , contains 10^15 microbes of 1,000 different species.
-
- 906 - Vaccines work because they are a variation of the microbe that causes your immune system to go to work.
-
- 959 - Bad microbes originate in animals and our bodies are not equipped to handle them.
-
- 881 - Microbes make climate change. Microbes may have arrived on Earth hitchhiking on meteorites.
-
- 989 - Extreme microbes. If you stop an antibiotic too soon some microbes might survive and mutate to become resistant to the antibiotic.
-
- 1654 - Everything about protons. The proton lifetime is 2.1*10^29 years.
-
- 979 - Calculating the mass of a proton.
-
- June 12, 2021 MICROBES - on Earth and the planets? 3190
----------------------------------------------------------------------------------------
----- Comments appreciated and Pass it on to whomever is interested. ----
--- Some reviews are at: -------------- http://jdetrick.blogspot.com -----
-- email feedback, corrections, request for copies or Index of all reviews
--- to: ------ jamesdetrick@comcast.net ------ “Jim Detrick” -----------
--------------------- --- Wednesday, June 16, 2021 ---------------------------
No comments:
Post a Comment