Chapter 1: The Misunderstood Microbes

While bacteria often have a negative reputation due to their association with illnesses, they play a critical role in maintaining the health of our planet. Many people go to great lengths to eliminate bacteria using antibacterial products, unaware of the invaluable services these microorganisms provide.

In fact, bacteria are ubiquitous, existing in massive colonies across diverse environments. For example, a single gram of soil can harbor around 40 million bacteria, while a millimeter of freshwater contains about one million. Inside our own bodies, trillions of these cells contribute to various biological processes.

Scientists have harnessed bacteria for a wide range of applications, including medical diagnostics and wastewater treatment. Their remarkable ability to decompose complex substances makes them invaluable in addressing pollution issues.

Bacteria's unique ability to break down materials stems from enzymes they produce. These microorganisms require nutrients for energy, but when they encounter substances too complex to digest, their enzymes catalyze reactions that simplify these materials into digestible components.

Different bacterial strains produce various enzymes, some of which can degrade even the most complex and hazardous substances. For instance, in 2016, researchers in Japan discovered a bacterial strain in a waste site that had evolved to consume polyethylene terephthalate (PET), a widely used plastic in products like water bottles. Approximately 30 million tons of PET are produced annually, with only 30 to 50 percent being recycled.

Discarded PET items can linger in landfills and oceans for centuries, largely due to the strong molecular bonds within the material. The newly identified bacterial species is the first known organism capable of breaking these bonds and facilitating decomposition.

Although the process isn't instantaneous, low-quality plastics can be fully degraded in six weeks, while tougher PET takes longer. Fortunately, scientists have inadvertently enhanced the enzyme PETase, making it 20 percent more effective at breaking down PET within just a few days. Further modifications may expedite this process even more.

This past March, another strain of bacteria was found to degrade polyurethane, a notoriously difficult plastic to recycle due to its complex molecular structure. Used across various industries, polyurethane releases toxic chemicals as it slowly degrades, often killing surrounding bacteria. However, this resilient bacterial species can thrive on polyurethane as its sole energy source.

As we grapple with the escalating plastic waste crisis, bacteria may soon offer a solution. However, researchers suggest that it could take up to a decade before bacteria can effectively consume significant amounts of plastic waste. In contrast, their role in addressing oil spills has already been demonstrated.

After the 2010 BP oil spill in the Gulf of Mexico, bacteria consumed a considerable portion of the natural gas and oil trapped underwater—around 200,000 tons—within a few months. Crude oil comprises up to 1,000 distinct chemical compounds, some of which are particularly challenging to degrade.

By studying the bacteria's genetic makeup, researchers identified specific enzymes that target hydrocarbons, revealing that various bacterial strains collaborate to break down these compounds more efficiently. The mixing of ocean currents further facilitated the transformation of millions of barrels of oil into approximately 100 sextillion bacterial cells.

However, bacteria cannot remediate every substance left behind after an oil spill, particularly larger compounds or smaller molecules lacking sufficient nutrients. Scientists are exploring ways to enhance the effectiveness of naturally occurring bacteria in oceans during future spills, particularly by ensuring that dispersants do not harm or kill these microorganisms.

More recently, researchers have turned their attention to the potential of bacteria to address the challenges of nuclear waste disposal. Given its radioactivity, nuclear waste requires careful management, often being stored underground in concrete enclosures, leading to alkaline environments that trigger specific chemical reactions.

One such reaction involves the breakdown of cellulose into isosaccharinic acid (ISA). When ISA forms, it can bind with unstable radionuclides, increasing their solubility and risking leakage into the environment. However, scientists have identified certain "extremophile" bacteria capable of thriving in high pH conditions. These bacteria can utilize ISA as a food source, degrading it and maintaining radionuclides in a solid state, preventing their escape.

As nuclear waste remains buried for thousands of years, these bacteria could provide an additional safeguard for our environment and health.

This video discusses how beneficial bacteria can help combat climate change and improve environmental health.

This video explores the potential of an ancient Siberian bacteria that might hold secrets to immortality, shedding light on its unique properties.