Эрдэмтэд газрын гүнийн тусгаарлагдсан орчинд амьдардаг бичил биетүүд өөр өөр үүрэг гүйцэтгэдэг тогтвортой экосистемийг бүрдүүлдэг болохыг илрүүллээ.
Нортвестерний их сургуулийн геобиологич Магдалена Осбурнаар удирдуулсан судалгааны баг АНУ-ын Өмнөд Дакота дахь “Homestake” уурхайн гүнээс 2015-2019 оны хооронд дээж авч судалгаа хийжээ. Тэд газрын гадаргаас 250-1500 метрийн гүнд орших зургаан өөр цэгээс шингэн болон хийн дээжийг цуглуулсан бөгөөд зарим ус нь 10,000 жилийн турш гүнд хадгалагдсан байсныг тогтоов.
Судлаачид бүх цэг дээр ижил төрлийн бичил биетүүд байх болов уу гэж таамаглаж байсан ч үр дүн нь тэс өөр байлаа. Байршил бүр өөрийн гэсэн өвөрмөц бүрэлдэхүүнтэй бичил биетний нийгэмлэгтэй байсан нь тухайн орчны геологи, химийн нөхцөл байдал тэдгээрийн оршин тогтнолд гол нөлөө үзүүлдэг болохыг харуулж байна.
Гэвч зүйлүүд нь харилцан адилгүй байсан ч экосистемийн ерөнхий бүтэц нь тууштай хадгалагджээ. Судлаачид бүх цэг дээр нүүрстөрөгчийг дахин боловсруулдаг үндсэн бүлэг болон хүхэр, азот, төмөр зэрэг шим тэжээлийг ашиглан идэвхждэг хоёр дахь бүлэг бичил биетүүдийг олж илрүүлсэн байна.
Эдгээр бүлгийг “функциональ гильд” буюу үүрэг гүйцэтгэгч бүлгүүд гэж нэрлэж байгаа бөгөөд газар хөдлөлт зэрэг хүчин зүйлээс шалтгаалан шим тэжээл ялгарах үед тэдгээр нь идэвхжиж, экосистемийн тэнцвэрийг хадгалдаг ажээ. Энэхүү нээлт нь дэлхийн гүнийн амьдрал хэрхэн зохион байгуулалттайгаар оршин тогтнодгийг шинжлэх ухааны түвшинд илүү тодорхой болголоо.
Дэлгэрэнгүйг эх сурвалжаас харах
↓Эх сурвалжийг нээх ↓
Far below Earth’s surface, in complete darkness and cut off from sunlight, microbes have found ways not just to survive, but to organize itself into functioning ecosystems. A new study has revealed that underground microorganisms form stable communities with different groups performing different tasks, helping life persist in some of the planet’s most isolated environments.
The findings come from a long-term investigation of the deep subsurface, a part of Earth that remains largely unexplored despite estimates suggesting it of the world’s microorganisms.
To better understand what happens beneath our feet, researchers studied microbial communities at the Sanford Underground Research Facility in Lead, South Dakota. The site, formerly known as the Homestake Mine, allowed scientists to collect samples from depths ranging from a few hundred meters to more than a kilometer below the surface.
Hidden Life Below Ground
Led by Northwestern University geobiologist Magdalena Osburn, the research team established six monitoring sites throughout the former mine.
Scientists drilled into surrounding rock formations and collected fluids flowing through natural fractures. These samples contained water, dissolved gases, and active microbial populations. The study, published in Journal of Geophysical Research: Biogeosciences, found that some of the water had remained trapped underground for as long as 10,000 years.
Researchers monitored the six sites between 2015 and 2019, creating one of the most detailed long-term records of deep underground microbial activity. Before the study began, scientists expected to find broadly similar microorganisms throughout the mine because the environments shared many of the same characteristics, including darkness, isolation, and limited energy resources.
“Within the goldmine, we sampled six spots, ranging from 250 meters deep to 1500 meters deep,” Osburn said. “We thought we might see some subtle variation with depth but assumed the microbial communities should be broadly similar. That’s not what we found at all.”
Even nearby sites often contained very different microbial populations. He compared the experience to sampling separate islands rather than different parts of the same ecosystem.
No Common Microbiome Emerged Across The Mine
The team had expected to identify a core group of microorganisms specially adapted to underground life. Instead, each location appeared to host its own distinct ecosystem shaped by local geological and chemical conditions.
“Because deep underground environments share extreme conditions, including darkness, isolation and limited energy, we thought we’d find a common set of specially adapted microbes,” Osburn noted. “But effectively, we found there is not a core microbiome anywhere in this mine. We did not expect that.”
The absence of a shared microbiome was one of the clearest results of the study. Rather than finding the same species across all six sites, researchers encountered unique microbial communities at every location.
This suggests that local conditions play a major role in determining which microorganisms can establish themselves underground, even within the same mine.
Microbes With Shared Functions
Although the species varied significantly from site to site, the overall structure of the ecosystems remained surprisingly consistent. Researchers identified two major groups of microorganisms at each location.
One group formed a stable core community that continuously recycled carbon and maintained basic biological processes. These microbes survived on very limited resources and appeared to operate at a slow pace over long periods.
A second group was ready to respond when new nutrients became available. These organisms consumed compounds containing sulfur, nitrogen, and iron, allowing the ecosystem to take advantage of occasional chemical changes.
“The core community has a low and slow metabolism,” Osburn explained. “Then this other community of organisms is poised to respond to pulses of nutrients when they become available.”
The researchers noted that events such as earthquakes can trigger underground chemical changes that release nutrients. When those opportunities arise, these microorganisms can quickly become active. Despite their differences, all six ecosystems contained microbes capable of performing similar ecological roles.
Scientists refer to these groups as functional guilds, meaning that different organisms can accomplish the same tasks. Osburn illustrated the concept with a simple analogy:
“I have a friend who says, ‘Every town needs a plumber.’ These sites reflect that idea. Each one is filled with different types of microbes, but all have a ‘plumber.’”
Enjoyed this article? Subscribe to our free newsletter for engaging stories, exclusive content, and the latest news.
