Name: pet-eating bacteria and enzyme breakdown
Uploaded: 2026-03-12T13:57:46.000Z
Duration: 1 min 28 s
Channel: JoVE

K12 Standards

Alabama Course of Study Science

9-12

Environmental Science

Earth and Human Activity

9-12.EVS.4.7

Microbial Bioremediation of Plastics

Plastic waste, especially from polyethylene terephthalate, or PET, is one of the most persistent pollutants.PET is made of repeating units of terephthalic acid and ethylene glycol, forming a durable, semi-crystalline structure.Ideonella sakaiensis is a bacterium capable of degrading PET and using its monomers as a carbon and energy source.This bacterium produces two key enzymes: polyethylene terephthalate hydrolase, or PETase, and mono (2-hydroxyethyl) terephthalate hydrolase, or MHETase. Together, they break down PET into its monomers.PETase hydrolyzes the PET polymer into mono(2-hydroxyethyl) terephthalic acid, or MHET.Occasionally, this step releases bis(2-hydroxyethyl) terephthalate or BHET as a minor intermediate, which can also be hydrolyzed by PETase into MHET.MHETase then breaks down MHET into ethylene glycol and terephthalic acid, which are metabolized by the bacterium.However, this process is slow and inefficient, often taking years to partially degrade a single plastic bottle.

microbial bioremediation of plastics

Polyethylene terephthalate (PET) is a synthetic polymer widely utilized in the packaging industry, particularly for bottles and containers. Due to its chemical stability and durability, PET accumulates in the environment, contributing significantly to plastic pollution. It comprises repeating units of terephthalic acid and ethylene glycol, resulting in a semi-crystalline structure that is resistant to natural degradation processes.A notable breakthrough in plastic biodegradation came with the discovery of Ideonella sakaiensis, a bacterium capable of utilizing PET as its primary carbon and energy source. This capability hinges on the bacterium's production of two specific enzymes: polyethylene terephthalate hydrolase (PETase) and mono(2-hydroxyethyl) terephthalate hydrolase (MHETase). PETase initiates the degradation process by hydrolyzing PET into mono(2-hydroxyethyl) terephthalic acid (MHET). Occasionally, PETase also produces bis(2-hydroxyethyl) terephthalate (BHET) as a secondary intermediate. BHET is further hydrolyzed by PETase or MHETase to yield MHET, which underscores the enzyme's versatility in handling multiple degradation intermediates.Following the production of MHET, MHETase catalyzes its conversion into the original monomeric components of PET: terephthalic acid and ethylene glycol. These monomers can then be assimilated into the bacterium's metabolic pathways, facilitating biomass generation and energy production. The stepwise enzymatic breakdown of PET by I. sakaiensis offers a promising biotechnological solution to mitigate plastic waste, as it not only reduces environmental persistence but also enables the recovery of valuable chemical constituents for potential reuse.Despite the promising nature of enzymatic PET degradation, several challenges hinder its large-scale application. The natural degradation rate by I. sakaiensis remains relatively slow, limiting its effectiveness in high-volume waste management scenarios. Moreover, PET's semi-crystalline regions are less accessible to enzymatic attack, reducing overall efficiency. Industrial deployment also requires optimization of enzyme stability, activity at ambient temperatures, and integration into waste management systems. Addressing these limitations through protein engineering, microbial consortia, and reactor design is crucial for translating laboratory successes into viable environmental and industrial applications.

Polyethylene terephthalate (PET) is a synthetic polymer widely utilized in the packaging industry, particularly for bottles and containers. Due to its ...

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Education

JoVE Core

Microbiology

Unit

Environmental Microbiology

KEY TERMS AND CONCEPTS

pet-eating bacteria and enzyme breakdown

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 enzymes: PETase, which stands for polyethylene terephthalate hydrolase, and MHETase, which stands for mono(2-hydroxyethyl) terephthalate hydrolase.

PETase starts the breakdown of PET by hydrolyzing it into mono(2-hydroxyethyl) terephthalic acid, or MHET. In some cases, PETase also produces bis(2-hydroxyethyl) terephthalate, or BHET, as an intermediate. BHET can then be hydrolyzed by PETase or MHETase to form MHET, showing that PETase can act on more than one degradation product.

MHETase completes the process by converting MHET into the original PET monomers, terephthalic acid and ethylene glycol. The bacterium can then use these monomers in its metabolic pathways to build biomass and make energy. This stepwise enzymatic process offers a promising way to reduce plastic waste and recover useful chemical building blocks for reuse.

Even so, several barriers remain before this approach can work on a large scale. Natural PET breakdown by I. sakaiensis is still slow, and the semi-crystalline parts of PET are harder for enzymes to reach. Industrial use also depends on improving enzyme stability, activity at room temperature, and integration into waste management systems. Protein engineering, microbial consortia, and reactor design may help turn this lab result into a practical environmental tool.

PET-Eating Bacteria and Enzyme Breakdown

microbial bioremediation of uranium

How Microbes Lock Up Uranium in Soil

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...

microbial bioremediation of hydrocarbons

How Bacteria Break Down Oil Spills

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...

microbial bioremediation of pesticides

How Microbes Break Down Pesticides

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...

microbial leaching

Bioleaching in Metal Recovery

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...

acid mine drainage

Pyrite Oxidation in Mine Water

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...

microbial wastewater treatment

Microbes in Water Pollution Cleanup

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...

microbial corrosion

How Microbes Damage Metal Surfaces

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

How Fungi Damage Surfaces

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...

microbial fuel cells

Electricity from Bacteria in Fuel Cells

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 and climate change

Microbes in Greenhouse Gas Cycles

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...

key terms and concepts

Learn how Ideonella sakaiensis uses PETase and MHETase to break down PET plastic into reusable monomers, and why the process still needs optimization.

PET-Eating Bacteria and Enzyme Breakdown | JoVE K12

JoVE Core Microbiology provides an engaging introduction to the microbial world and its influence on health, industry, and the environment. This comprehensive collection covers key concepts such as microbial structure, metabolism, genetics, and ecology. It introduces essential laboratory techniques and microscopy methods through visually engaging animations. Corresponding scientist-in-action videos bridge classroom concepts with real-world research and applications.

microbiology

biofuels-producing-ethanol-from-cellulosic-material

Biofuels: Producing Ethanol from Cellulosic Material

Source: Laboratories of Margaret Workman and Kimberly Frye - Depaul University
In this experiment, cellulosic material (such as corn stalks, leaves, ...

Biofuels

The microbial conversion of organic matter into biofuels holds potential as a renewable energy source. Among biofuel sources, microalgae are recognized as ...

Enthalpy and Heat of Reaction

Combustion, commonly known as burning, is a reaction in which a substance reacts with an oxidizing agent, which in most cases is molecular oxygen, to ...

Enthalpies of Reaction

Hess&rsquo;s law can be used to determine the enthalpy change of any reaction if the corresponding enthalpies of formation of the reactants and products ...

Proton Exchange Membrane Fuel Cells

Source: Laboratories of Margaret Workman and Kimberly Frye - Depaul University
The United States consumes a large amount of energy &#8211; the current ...

6. Obtain, evaluate, and communicate information to describe the use of renewable and nonrenewable energy sources. Examples: Describe the similarities and differences among fossil fuels. Gather and share information to describe different sources of renewable energy from biomass such as biodiesel, cellulosic ethanol, and algae.

9-12.EVS.4.6

Dye-sensitized Solar Cells

Source: Tamara M. Powers, Department of Chemistry, Texas A&#38;M University
Today&#39;s modern world requires the use of a large amount of energy. While ...

Light as Energy

The energy required to carry out photosynthesis is light&#8212; typically electromagnetic radiation from the sun. The range of all possible wavelengths is ...

gis-software-hardware-and-sources-of-gis-data

GIS Software, Hardware, and Sources of GIS Data

A Geographic Information System (GIS) combines specialized software and hardware to effectively manage, analyze, and present spatial and related data. GIS ...

a. Analyze and interpret data on the origins and availability of renewable and nonrenewable forms of energy to predict consumption trends. Examples: Use a solar irradiance map to predict the best area for a solar thermal power plant. Analyze the distribution of fossil fuel reserves around the globe to identify energy-rich and energy-poor areas and predict future trends in types of fuel used and rates of consumption.

9-12.EVS.4.6.a

Manipulation and Analysis

GIS manipulation and analysis functions are vital for decision-making and planning. These activities range from data retrieval tasks, such as selecting ...

Climate Change

The certainty of climate change remains a public controversy despite the consensus among approximately 97% of active climate researchers, who not only ...

Microbes and Climate Change

Microorganisms are pivotal agents in Earth's biogeochemical cycles, significantly influencing climate dynamics through their metabolic activities. These ...

Coordinates and Map Projections

Coordinates and map projections are essential tools in accurately representing the Earth's surface for various applications, ranging from navigation to ...

b. Construct an argument based on data about the risks and benefits of using renewable and nonrenewable energy sources in Alabama.

9-12.EVS.4.6.b

Quarrying of Stone

Quarrying involves the meticulous extraction of stone from a quarry by either using controlled explosions or precision cutting techniques to remove the ...

Properties of Transition Metals

Transition metals are defined as those elements that have partially filled d orbitals. As shown in Figure 1, the d-block elements in groups 3&#8211;12 are ...

Bioplastics

Bioplastics derived from microbial processes present a sustainable alternative to conventional petroleum-based plastics. Among these, ...

7. Obtain, evaluate, and communicate information to describe the development, management, and recycling of mineral resources. Example: Research technologies used to mine and process rare Earth metals for electronics. Gather information and draw conclusions about the sustainability of plastics recycling.

Nutrients in Aquatic Ecosystems

Source: Laboratories of Margaret Workman and Kimberly Frye - Depaul University
Nitrogen and phosphorus are essential plant nutrients found in aquatic ...

The Nitrogen Cycle

Nitrogen atoms, present in all proteins and DNA, are recycled between abiotic and biotic components of the ecosystem. However, the primary form of ...

The Phosphorus Cycle

Unlike carbon, water, and nitrogen, phosphorus is not present in the atmosphere as a gas. Instead, most phosphorus in the ecosystem exists as compounds, ...

The Sulfur Cycle

Sulfur, an important element in the chemical makeup of proteins, is recycled through the atmosphere and aquatic and terrestrial environments. Found in the ...

Using GIS to Investigate Urban Forestry

Source: Laboratories of Margaret Workman and Kimberly Frye - Depaul University
Urban forests broadly include urban parks, street trees, landscaped ...

Biological Clocks and Seasonal Responses

The circadian&#8212;or biological&#8212;clock is an intrinsic, timekeeping, molecular mechanism that allows plants to coordinate physiological activities ...

Pollination and Flower Structure

Flowers are the reproductive, seed-producing structures of angiosperms. Typically, flowers consist of sepals, petals, stamens, and carpels. Sepals and ...

8. Construct or revise a claim based on evidence of the effects of human activities on Earth's systems, natural resources, and ecosystem services. Examples: Construct a claim that excess nitrogen and phosphorus causes algal blooms, deforestation disrupts carbon storage, or excess atmospheric sulfur leads to acid rain. Construct a claim that changing rain patterns cause flooding or desertification. Construct a claim that temperature cycles affect the timing of migrations and the flowering of plants, causing a disjunction in pollination.

9-12.EVS.4.8

What is Photosynthesis?

All living organisms on Earth are directly or indirectly dependent on photosynthesis. It is the only biological process that can capture energy from ...

The Calvin Cycle

Overview

Oxygenic photosynthesis converts approximately 200 billion tons of carbon dioxide (CO2) annually to organic compounds and produces approximately ...

Marine Microbial Ecology

Marine microbial ecosystems are shaped by distinct physicochemical limits, including high salinity, low nutrient availability, and fluctuating oxygen ...

a. Evaluate published information from computational models which illustrate the effects of an increase in atmospheric carbon dioxide on photosynthesis and the effect of ocean acidification on marine populations.

9-12.EVS.4.8.a

determination-of-nox-in-automobile-exhaust-using-uv-vis-spectroscopy

Determination Of NOx in Automobile Exhaust Using UV-VIS Spectroscopy

Source: Laboratories of Margaret Workman and Kimberly Frye - Depaul University
In the troposphere, ozone is naturally formed when sunlight splits nitrogen ...

Bioremediation

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Microbial Bioremediation of Hydrocarbons

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Microbial Bioremediation of Pesticides

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b. Use engineering practices to evaluate and refine a current solution designed to protect natural resources from anthropogenic sources of atmospheric, terrestrial, or aquatic pollution. Example: Create mechanisms to remove plastic from the ocean or particulates from industrial exhaust.

9-12.EVS.4.8.b

applications-of-gis-disaster-management-and-emergency-response

Applications of GIS: Disaster Management and Emergency Response

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Ecological Disturbance

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What are Biogeochemical Cycles?

The most common elements in organic molecules, carbon, hydrogen, oxygen, nitrogen, sulfur, and phosphorus, are only available in the ecosystem in limited ...

9. Obtain, evaluate, and communicate information based on evidence to explain how key natural resources, natural hazards, and climate variability influence human activity and welfare.

9-12.EVS.4.9

Stratified Sampling Method

Sampling is a technique to select a portion (or subset) of the larger population and study that portion (the sample) to gain information about the ...

a. Communicate scientific information about how environmental change may disproportionately impact people in certain socioeconomic groups or geographic locations. Examples: People in lower socioeconomic groups or those who are unhoused are more affected by rising temperatures and heat islands than others. Populations living at lower sea levels are more impacted by sea level rise than those who live at higher elevations. People living in floodplains are more likely to experience seasonal flooding than those living on higher ground.

9-12.EVS.4.9.a

Genetic Drift

Natural selection&#x2014;probably the most well-known evolutionary mechanism&#x2014;increases the prevalence of traits that enhance survival and ...

Gene Flow

Gene flow is the transfer of genes among populations, resulting from either the dispersal of gametes or from the migration of individuals.

This ...

Conservation of Small Populations

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Conservation of Declining Populations

Conservation of declining population focuses on ways of detecting, diagnosing, and halting a population decline. The approach uses methods to prevent ...

Habitat Fragmentation

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10. Use mathematics and graphic models to communicate how human activity may affect genetic variation in organism populations, including threatened and endangered species.

9-12.EVS.4.10

Population Growth

Population size is dynamic, increasing with birth rates and immigration, and decreasing with death rates and emigration. In ideal conditions with ...

Population Models
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Key Elements for Plant Nutrition

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11. Construct an explanation of how human populations undergo growth and decline. Examples: Explain how birth and death rates, infant mortality, nutrition, and other factors increase or decrease human populations. Clarification: Use of mathematical calculations to determine growth rate is not required.

9-12.EVS.4.11

What are Populations and Communities?

Populations are groups of individuals of the same species that inhabit a shared environment. Communities include multiple co-existing, interacting ...

How Data are Classified: Categorical Data

A variable, usually notated by capital letters such as X and Y, is a characteristic or measurement that can be determined for each member of a population. ...

a. Analyze and interpret data on human population trends in developing and developed countries and in the global population as a whole. Example: Use fertility and mortality rates to predict population growth and average population age during different stages of the demographic transition model. Compare age structure diagrams of developing and developed countries to determine differences in population growth rates. Use total fertility rates to predict global population growth rate.

9-12.EVS.4.11.a

Biodeterioration

Biodeterioration refers to the unwanted alteration of materials caused by microorganisms&#8212;especially fungi&#8212;which damage both organic substrates ...

b. Construct explanations of the types of environmental impacts produced by human populations in each stage of the demographic transition model. Example: Current American quality of life standards from post-industrial development (driving a car, heating and cooling a house) can have a negative impact on the environment. As quality of life, educational opportunities, and gross national product increase, individual resource consumption increases. Transitioning populations may generate increased local solid waste pollution.

9-12.EVS.4.11.b

Global Climate Change

Throughout its ~4.5 billion year history, the Earth has experienced periods of warming and cooling. However, the current drastic increase in global ...

12. Obtain, evaluate, and communicate information to describe the effects of human population growth on global ecosystems.

9-12.EVS.4.12

Testing For Genetically Modified Foods

Source: Laboratories of Margaret Workman and Kimberly Frye - Depaul University
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Plant Breeding and Biotechnology

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Production of Biopesticides

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Plant Tissue Culture

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a. Evaluate and communicate information describing the impact of measures used to increase the food supply for the growing human population, including the use of GMOs, monocultures, integrated pest management (IPM), and precision agriculture.

9-12.EVS.4.12.a

Measuring Tropospheric Ozone

Source: Laboratories of Margaret Workman and Kimberly Frye - Depaul University
Ozone is a form of elemental oxygen (O3), a molecule of three oxygen atoms ...

turbidity-and-total-solids-in-surface-water

Turbidity and Total Solids in Surface Water

Source: Laboratories of Margaret Workman and Kimberly Frye - Depaul University
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Survey Safety

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b. Evaluate and communicate information describing the effects of urbanization on the environment. Examples: Creating impervious surfaces such as roads, parking lots, and sidewalks increases flash flooding in low-lying urban areas. Urban sprawl leads to increased use of fossil-fuel-powered transportation and higher levels of local air pollution. An increase in pavement and rooftops and a decrease in green space leads to heat islands.

9-12.EVS.4.12.b

Sustainable Development

As the human population continues to grow and use resources, we must be mindful of our planet&rsquo;s natural limits. Sustainable development provides a ...

13. Design and defend a sustainability plan to reduce an individual's ecological footprint, taking into account how market forces and societal demands influence personal choices.

9-12.EVS.4.13

PET-Eating Bacteria and Enzyme Breakdown

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