Ancient bacteria species among the first of its kind to colonize land

A species of bacteria that lived 407 million years ago would have flourished among early land plants.

Detailed 3D reconstructions of fossils discovered in Scotland are helping scientists to understand more about how microbial life affected early terrestrial ecosystems.

Cyanobacteria evolved early in our planet’s history and played a significant role in shaping life as we know it.

These tiny microorganisms have been well documented in marine rocks, but scientists are trying to understand more about how they first colonized land.

Langiella scourfieldii is a species of cyanobacteria which is part of the Hapalosiphonaceae family and grew among early land plants more than 400 million years ago in the Early Devonian.

A new study published in iScience reveals that L. scourfieldii is the oldest species of the Hapalosiphonaceae known to have colonized land. It would have thrived in soils, freshwater and hot springs, much like its living relatives do today.

Dr. Christine Strullu-Derrien, a Scientific Associate at the Museum and lead author of the study says, “With the 3D reconstructions, we were able to see evidence of branching, which is a characteristic of Hapalosiphonacean cyanobacteria. This is exciting because it means that these are the earliest cyanobacteria of this type found on land.”

What are cyanobacteria?Cyanobacteria are an ancient group of microorganisms. Their fossils are among the earliest ever discovered, with the oldest widely accepted ones dating to around 2 billion years ago.

Today, they are one of the largest and most important groups of bacteria. They live in and around aquatic environments virtually everywhere on Earth, including oceans, freshwater, damp soil, and even Antarctic rocks.

Although small and typically unicellular, cyanobacteria often grow in colonies large enough to see with the naked eye and are known for their extensive blooms that turn the water’s surface blue-green.

These tiny organisms have played a significant role in shaping the evolution of life. They photosynthesize in a similar way to plants and are responsible for helping to create our oxygen-rich atmosphere.

Around 2.4 billion years ago, masses of photosynthesizing cyanobacteria initiated the Great Oxygenation Event, when oxygen began to replace other gases like methane in the atmosphere. This led to what many scientists have described as Earth’s first mass extinction as organisms that were adapted to anaerobic life began to die out.

Cyanobacteria probably originated in freshwater environments, so scientists believe they started to colonize land early in their history.

“Cyanobacteria in the Early Devonian played the same role that they do today,” says Christine. “Some organisms use them for food, but they are also important for photosynthesis. We have learnt that they were already present when plants first began colonizing land and may have even competed with them for space.”

How was Langiella scourfieldii discovered?L. scourfieldii was first discovered in 1959 alongside two other species from a rock fragment found in the Rhynie Chert fossil site in Aberdeenshire.

The original descriptions were based on specimens in the Museum’s collections, but more recently, similar specimens discovered in the collections of the Sorbonne University in Paris were found to be from the same species.

“The three species of cyanobacteria described in 1959 were described from a small piece of rock that is very difficult to photograph and study,” Christine says.

“Fortunately, we found new samples from the Rhynie Chert containing cyanobacteria that we could study in more detail using the confocal microscope.”

One of the main characteristics of this type of bacteria is the presence of what is known as “true branching.” This occurs when individual bacteria grow alongside each other in a line, with some lines breaking off in different directions to create a branching structure.

While remains of cyanobacteria are relatively common in the Rhynie Chert, many do not display this true branching. By finding it in L. scourfieldii, researchers could confirm the bacteria’s presence in this ecosystem.

What did the Rhynie Chert look like in the Early Devonian?More than 400 million years ago, the landscape of Aberdeenshire would have looked considerably different from today.

Much of Earth’s landmass was located in the Southern Hemisphere. Scotland lay just south of the Equator and would have experienced a tropical to sub-tropical climate.

The Rhynie Chert, meanwhile, would have been an area of sandy flatland with shallow pools of fresh to brackish water. Volcanic activity and hot springs in the area would mean that it likely resembled the modern Yellowstone Nation Park.

That said, its biodiversity would have looked very different, as the Early Devonian was before forests and vertebrates started to become dominant on land.

Instead, the focus of life would have been on moist rocks near pools of water. These would have been covered by microbial mats consisting of bacteria, algae and fungi.

As the soil at the time was not deep, plants did not have complex root systems so instead grew on these microbial mats attached by small structures called rhizoids.

At some point, silica released from hot springs settled around the organic material, rapidly preserving it in chert, which is a finely crystalline quartz. The exceptional preservation of these organisms makes the Rhynie Chert a globally important site for scientists.

“The Rhynie Chert is an iconic site because it’s 400 million years old, and much of the environment from this time has been preserved,” says Christine.

“It is the only site where you find traces of all the organisms together: the plants, animals, fungi, bacteria and algae. You can see the interactions between species that would have taken place.”

More information: Christine Strullu-Derrien et al, Hapalosiphonacean cyanobacteria (Nostocales) thrived amid emerging embryophytes in an early Devonian (407-million-year-old) landscape, iScience (2023). DOI: 10.1016/j.isci.2023.107338

This story is republished courtesy of Natural History Museum. Read the original story here.

Citation: Ancient bacteria species among the first of its kind to colonize land (2023, September 11) retrieved 13 September 2023 from https://phys.org/news/2023-09-ancient-bacteria-species-kind-colonize.html

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Climate Change and Terrestrial Ecosystem Modeling

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03

This Start-Up Taps Into A Hidden World To Restore Biodiversity And Capture CO2

Fruits of underground fungi working hard to decompose a tree stump

Upsplash Executive SummaryHumans often overlook the most important things in life. Scientists are just starting to understand that we are only able to enjoy the shade and grandeur of a stand of Giant Sequoias or revel in the mélange of wildflowers in a meadow thanks to a complex, interconnected ecosystem of tiny organisms we never see in daily life. One start-up, headed by a world-renowned expert in forest soils and the organisms living there, took a moment to smell the flowers. He and his company have found an interesting way to pay landowners to increase biodiversity and slow the progress of climate change.

Dr. Colin Averill, founder and CEO of Funga

Dr. Colin Averill / FungaFunga is an Ag Tech start-up leveraging recent advances in mycology—the study of fungi—to increase the carbon sequestration capacity of commercial pine tree plantations. It was founded by Dr. Colin Averill, a world-renowned expert on mycorrhizal networks, a type of fungi that forms symbiotic relationships with trees that enables the trees to grow quicker and to adapt more easily to climactic changes.

The company generates revenues by selling high-quality carbon credits on the additional carbon stored by trees after the soils are “inoculated” with a community of mycorrhizae and other microscopic soil dwellers that Funga scientists select with the help of vast datasets and machine learning algorithms.

Funga announced in February that it had closed a $4 million financing with several leading venture capital investors. Averill and his team are using that money to develop carbon credit projects in pine plantations in the southeastern United States with plans to soon expand globally.

Funga’s Founder and Brief Company HistoryFunga’s founder and CEO, Averill, is an expert in the role of mycorrhizal networks in forested ecosystems. He is well-respected in his field, having made important advances to scholarship during his doctoral and post-doctoral research at the world-famous Crowther Lab at ETH Zurich, a leading institution for environmental research and the alma mater of none other than Albert Einstein.

Averill says he originally got the idea for Funga in 2021 while working as a researcher at the Crowther Lab and began the process of shaping a business plan and raising start-up capital in 2022. Supported by Averill’s strong background, the scientific rigor with which he is working, and the underlying demand for high-quality carbon credits from corporate buyers, the fundraising proceeded quickly.

Funga announced in February, 2023 that it had closed a $4 million financing round led by Azolla Ventures with participation from Better Ventures, Trailhead Capital, and Shared Future Fund. Averill was able to hire a team of about a dozen scientists and forestry experts, who are working hard to scale up Funga as a business worldwide.

I was curious about how Averill has found the transition from scientist to entrepreneur. He told me that some skills were quite portable—writing grant proposals to fund research projects is similar to preparing a pitch deck to shop around to VCs, for instance. Funga’s vibe is collegial, so feels similar to an academic laboratory.

When discussing cultural differences between academe and industry, he expressed an idea that I had heard from other academics as well: the academic world is a terrific place to explore new ideas, but is not the ideal environment to try to scale these ideas into world-changing movements. Recognizing the desperate need for large-scale, easily implementable solutions to the dual crises of climate and biodiversity loss, he felt called to start Funga.

The Science behind FungaA few years ago, politicians got very excited about some research out of the Crowther Lab that suggested humans could reverse a decade’s worth of the carbon cycle imbalance causing climate change by planting a trillion trees. President Trump even mentioned and praised the “Trillion Tree Initiative” in his 2020 State of the Union Address.

As if on cue, countries and organizations were touting their tree planting initiatives.

However, research out of Stanford suggests that, unless afforestation programs are structured intelligently, overseen diligently, and managed proactively, tree planting can actually decrease biodiversity and have negligible or negative effects on carbon sequestration.

The big problem with the naive tree planting idea is that we humans, seeing only the trunks, branches, and leaves above ground, have no understanding (and therefore no appreciation) for the complexity of the biosphere flourishing within the soil of a healthy, natural forest.

My favorite Japanese poet and calligrapher, Mitsuo Aida, executed a wonderful work which, translated into English, goes something like this:

“A water main running underground / A sewage pipe under a skyscraper / The most important things do not appear on the surface.” (translated by the author)

Over the past few years, scientists have been taking a closer look at the importance of the soil microbiome—the bacteria, protists, archaea, and fungi that make up a world of life that is normally completely invisible to us surface dwellers—and the revelations from their work have been profound.

Their work showed that the soil microbiome governs the biogeochemical cycling of plant macronutrients (e.g., nitrogen, phosphorous, and potassium) and micronutrients (e.g., boron, manganese, and copper). Mycorrhizae are filamentous fungi that form a critical component of the soil microbiome. Some species of mycorrhizae grow in sheaths around plants’ roots and some even burrow into them—forming a tight, symbiotic relationship between the themselves and the plants.

https://commons.wikimedia.org/wiki/File:Mutualistic_mycorrhiza_en.svg Creative Commons License: … [+] https://creativecommons.org/licenses/by-sa/4.0

Nefronus, via Wikimedia CommonsMycorrhizae have evolved to capture certain nutrients and minerals necessary for plant growth from the soil and use those nutrients as “currency” which they exchange for sugars (i.e., carbon-containing molecules) created by the plants during photosynthesis. The symbiotic relationship between fungi and plants is so important that scientists believe the partnership was the main factor allowing the emergence of life on land.

If the soil contains too few organisms or a broad enough selection of organisms, the soil is said to lack biodiversity and the trees end up not being provided with the necessary nutrients. In this case, rather than taking in additional carbon dioxide from the atmosphere, trees will be forced to slough it off through the process of “respiration”—breathing out carbon dioxide just like we animals do.

In exchange for the fungi providing nutrients to trees, trees pass fungi a substantial amount of the carbon dioxide they capture during the photosynthetic process. According to a recent scientific study, each year, mycorrhizal networks end up receiving and sequestering the equivalent of nearly two-fifths of the CO2 emissions that humans created from burning fossil fuels during all of 2021.

In other words, the forests we cannot see—the forests of microscopic fungi, bacteria and the like, which live within the soil of the forests we can see—end up doing a lot of the heavy lifting of atmospheric carbon sequestration.

The carbon sequestration services provided by fungi have one big drawback. If the soil is dug up, much of the carbon sequestered there is released back into the atmosphere. Land use changes—converting forestland to farmland, plowing farmland, or cutting roads through forests (i.e., everything that is happening in the Amazon basin right now)—all do great damage to soil ecosystem biodiversity and thus to the soil’s ability to sequester carbon.

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