Environmental Microbiology

Microbes can help lock up uranium in contaminated soil and water. They do this through bioreduction, biosorption, bioaccumulation, and biomineralization. These pathways lower uranium toxicity and help stop it from moving through groundwater.

Bioreduction is one of the main microbial pathways. Anaerobic bacteria such as some Geobacter and Shewanella strains use U(VI) as a terminal electron acceptor. Their c-type cytochromes, including OmcA and MtrC, help convert soluble, mobile U(VI) into...

Bacteria can help break down oil spills and other hydrocarbon pollution through bioremediation. This process uses living organisms, mainly microorganisms, to degrade or neutralize pollutants in contaminated environments. It is a natural, cost-effective, and environmentally friendly alternative to physical or chemical cleanup methods.

In marine settings, Alcanivorax borkumensis is a key bacterium that uses hydrocarbons as a source of carbon and energy. It grows at the oil-water interface, where...

Polyethylene terephthalate, or PET, is a common plastic used in bottles and containers. It is a synthetic polymer with repeating units of terephthalic acid and ethylene glycol. Its stable, semi-crystalline structure makes it hard to break down naturally, so it builds up in the environment and adds to plastic pollution.

A major breakthrough in PET degradation was the discovery of Ideonella sakaiensis. This bacterium can use PET as its main source of carbon and energy. Its ability depends on two...

Microbes can help break down pesticides that are hard to remove from the environment. Many pesticides have halogen groups and multiple aromatic rings, which make them chemically stable. That stability helps them resist natural degradation and lets residues build up in ecosystems, where they can affect non-target organisms.

Some microorganisms can use these pesticides as a source of carbon or energy. The breakdown process often begins with dechlorination, which is the enzymatic removal of...

Bioleaching uses microorganisms to help extract metals from low-grade ores. It is also called microbial leaching. This method is useful in mining for copper, gold, and uranium, especially when traditional extraction is too costly or causes too much environmental damage.

Copper bioleaching begins with crushed ore piled into heaps. The heaps are irrigated with dilute sulfuric acid. The acid dissolves some copper and creates conditions that favor acid-loving bacteria such as Acidithiobacillus...

Pyrite oxidation in mine water can start a chain reaction that damages streams and lakes. When mining exposes sulfide-rich rocks, especially pyrite (FeS2), to air and water, the mineral begins to break down. This process releases sulfate and can form sulfuric acid. It also mobilizes heavy metals into nearby water systems. The result is acid mine drainage, or AMD, which produces low-pH water with toxic elements that can harm aquatic life and water quality.

Pyrite can oxidize without help from...

Microbes help clean polluted water by breaking down contaminants from domestic and industrial waste. These microorganisms act like biological catalysts. They transform both organic and inorganic pollutants as water conditions change.

In oxygen-rich surface water, aerobic heterotrophs drive the first stage of breakdown. Aerobic means using oxygen, and heterotrophs are organisms that use organic matter for energy. They use oxygen as the final electron acceptor and turn many substrates into...

Microbiologically influenced corrosion, or MIC, is metal damage caused by the metabolic activity of microorganisms. It is a major problem in oil and gas, maritime, and water treatment settings. MIC happens when bacteria, archaea, and fungi colonize metal surfaces and form biofilms that change the local electrochemical environment.

These biofilms can trap corrosive agents and speed up localized corrosion. Microbes also produce substances such as hydrogen sulfide and organic acids, which attack...

Biodeterioration is the unwanted damage of materials caused by microorganisms, especially fungi. It can affect organic materials such as paper, wood, and textiles, as well as inorganic materials such as stone, plaster, and glass. Unlike simple nonliving decay, this damage comes from biological activity that causes both physical disruption and chemical breakdown.

Fungal hyphae, which are thread-like growths, can enter pores, cracks, and rough surface areas. Their turgor pressure and...

At the cathode, catalysts such as platinum or manganese oxide help oxygen react with electrons and protons to form water. This completes the circuit and keeps charge balanced. Because microbial fuel cells can use many kinds of organic waste, they are useful for environmental cleanup and may help power remote sensors or support wastewater treatment facilities. Their main limits include low power density, high electrode costs, and the challenge of scaling the system.

Microbes help move carbon and nitrogen through Earth's climate system. Their metabolism can add greenhouse gases to the air, and in some cases, it can also remove them. These tiny organisms are active in soil, water, wetlands, and the ocean.

Warming temperatures can speed up microbial metabolism. As microbes break down organic matter faster, they release carbon dioxide, or CO2, through respiration. Thawing permafrost can also wake up dormant microbial communities. When those microbes grow and...