April 30, 2024

Ancient Microbial “Dark Matter” – Thousands of Unknown Bacterial Species Discovered in Hawaiian Lava Caves

Steve Smith in a Hawaiian cave passage filled with roots of the Kaʻu district on the Island of Hawai`i. Credit: Kenneth Ingham
Centuries-Old Lava Caves of Hawaiʻi Island Contain Thousands of Unknown Bacterial Species
Greater bacterial variety than researchers expected has actually been discovered in the lava caves, lava tubes, and geothermal vents on the huge island of Hawaiʻi. The findings have actually been reported in a new research study published today (July 21, 2022) in the journal Frontiers in Microbiology.
This research examines the variety and interactions within these microbial communities, which illustrate how life might have existed on Mars and the early Earth in the past. Remarkably, the findings showed that a class of bacteria known as Chloroflexi are typically “center” species, suggesting that they are gotten in touch with numerous other types and usually play vital eco-friendly functions in the community. Numerous Chloroflexi species are little understood, and more research study will expose previously undiscovered types, in addition to insights into the role these species play in these severe environments.
” This study points to the possibility that more ancient lineages of bacteria, like the phylum Chloroflexi, may have crucial eco-friendly tasks, or functions,” stated very first author Dr. Rebecca D Prescott of NASA Johnson Space Center and University of Hawaiʻi at Manoa, in the United States. “The Chloroflexi are an incredibly varied group of bacteria, with lots of different functions found in great deals of various environments, however they are not well studied and so we do not know what they perform in these neighborhoods. Some researchers call such groups microbial dark matter– the un-studied or unseen bacteria in nature.”

Unseen volcanic life
Prescott and her colleagues gathered 70 samples from a range of areas, consisting of active geothermal vents (fumaroles), along with “more youthful” and “older” lava tubes and caves, which were under 400 years of ages and between 500 and 800 years old, respectively, to get a sense of how the bacterial neighborhoods may alter with time. They had the ability to identify the diversity and abundance of the bacterial classes in each sample by sequencing the ribosomal RNA present in the samples. Co-occurring bacterial networks also offered hints relating to possible interactions between these microbes.
Thick microbial mats hang under a rock ledge in steam vents that run along the Eastern Rift Zone on Hawaiʻi Island. Credit: Jimmy Saw
The harshest conditions– the geothermal sites– were anticipated to have lower diversity than the more established and habitable lava tubes. While the diversity was certainly discovered to be lower, the team of researchers was shocked to discover that the interactions within these neighborhoods were more complex than in places with higher diversity.
” This leads to the concern, do extreme environments help develop more interactive microbial neighborhoods, with bacteria more reliant on each other?” said Prescott. “And if so, what is it about severe environments that assists to develop this?”
Considering that Chloroflexi, and another class called Acidobacteria, existed at nearly all of the areas, they might play essential roles in these communities. However, these were not the most abundant bacteria, and the private neighborhoods from the different websites revealed large variations in the diversity and intricacy of the microbial interactions. Counterintuitively, the most plentiful groups, Oxyphotobacteria and Actinobacteria, were rarely hub types, recommending that their roles may be less essential to the total structure of the community.
More concerns than answers
Given that the current research study was based on the partial sequencing of one gene, it can not precisely determine the species of microbes or their tasks in the community. Additional research is required to assist reveal the specific species that are present, as well as to much better comprehend these bacterias roles in the environment.
A stalactite formation in a Hawaiian cave system from this study with copper minerals and white microbial colonies. Regardless of the reality that copper is toxic to lots of organisms, this development hosts a microbial community. Credit: Kenneth Ingham
” Overall, this study helps to illustrate how essential it is to study microbes in co-culture, rather than growing them alone (as isolates),” stated Prescott. “In the natural world, microbes do not grow in isolation. Instead, they grow, live, and communicate with many other microorganisms in a sea of chemical signals from those other microbes. This then can modify their gene expression, affecting what their jobs are in the neighborhood.”
Beyond the insights about past, or perhaps future, life on Mars, bacteria from volcanic environments can likewise work in comprehending how microorganisms turn volcanic rock (basalt) into soils, as well as bioremediation, biotechnology, and sustainable resource management.
Recommendation: “Islands Within Islands: Bacterial Phylogenetic Structure and Consortia in Hawaiian Lava Caves and Fumaroles” by Rebecca D. Prescott, Tatyana Zamkovaya, Stuart P. Donachie, Diana E. Northup, Joseph J. Medley, Natalia Monsalve, Jimmy H. Saw, Alan W. Decho, Patrick S. G. Chain and Penelope J. Boston, 21 July 2022, Frontiers in Microbiology.DOI: 10.3389/ fmicb.2022.934708.
Financing: NASA Headquarters, George Washington University.

“The Chloroflexi are an incredibly varied group of germs, with lots of various roles found in lots of different environments, however they are not well studied and so we do not understand what they do in these neighborhoods. Prescott and her associates collected 70 samples from a range of places, including active geothermal vents (fumaroles), as well as “younger” and “older” lava tubes and caverns, which were under 400 years old and in between 500 and 800 years old, respectively, to get a sense of how the bacterial communities might change over time. Because Chloroflexi, and another class called Acidobacteria, were present at almost all of the places, they may play necessary functions in these neighborhoods. These were not the most abundant bacteria, and the specific communities from the various websites showed big variations in the diversity and complexity of the microbial interactions. Counterintuitively, the most plentiful groups, Oxyphotobacteria and Actinobacteria, were not frequently center species, recommending that their functions might be less crucial to the general structure of the community.