Ecosystembacteria

Ecosystembacteria are bacteria that inhabit natural and managed ecosystems and contribute to their structure and function through metabolic activity. They are highly diverse and occupy soils, freshwater and marine environments, sediments, plant surfaces, and animal guts, as well as extreme habitats. They are not a single lineage but a broad collection of prokaryotes that interact with other organisms and abiotic factors.

In ecosystem processes, these bacteria drive decomposition and nutrient release, underpinning nutrient cycles. They participate in carbon cycling through decomposition and, in photosynthetic members such as cyanobacteria, primary production. They mediate nitrogen cycling via nitrification and denitrification, and some fix atmospheric nitrogen. They also influence sulfur and phosphorus cycles, and methane-oxidizing bacteria contribute to methane turnover in certain habitats.

Many ecosystembacteria form biofilms and engage in symbiotic relationships with plants, animals, and other microbes. Rhizobia fix nitrogen in legume root nodules, while gut-associated communities influence host digestion and immunity. Through these interactions, bacteria affect soil structure, plant health, and ecosystem resilience, and they can catalyze pollutant degradation, aiding bioremediation and wastewater treatment.

Studying ecosystembacteria relies on cultivation-independent methods such as 16S rRNA gene sequencing and metagenomics, as well as traditional culture-based approaches. Challenges include immense diversity, functional redundancy, and many taxa being difficult to culture or characterize.

Ecosystembacteria are essential drivers of ecosystem services, supporting productivity, water quality, pollutant degradation, and climate regulation through their roles in nutrient and energy flows.