Grade 12

Advanced

10 min

Lesson 12 of 12

Biotechnology for Sustainable Development

Not Started

Synthesizes biotechnology and ecology to address the UN Sustainable Development Goals through scientific innovation.

What if we could treat our planet's waste not as a burden, but as the raw 'code' to power our cities and resurrect lost species?

Learning Objectives

1.Describe how synthetic biology can contribute to a circular bioeconomy
2.Evaluate the role of biofuels and microbial fuel cells in reducing carbon footprints
3.Synthesize the potential of biotechnology to mitigate the impacts of the Sixth Mass Extinction

The Circular Bioeconomy

Traditional economies follow a 'take-make-dispose' linear model. In contrast, a circular bioeconomy mimics nature by ensuring that waste from one process becomes the feedstock for another. Synthetic Biology (SynBio) is the engine of this transition. By 'writing' new DNA sequences, scientists can engineer microorganisms like E. coli or yeast to convert agricultural waste (lignocellulose) into high-value bioplastics, pharmaceuticals, or textiles. This reduces our reliance on fossil fuels and minimizes landfill contributions. The goal is to close the loop, where the carbon emitted during a product's life cycle is exactly equal to the carbon captured during its production, represented by the net flux equation:

\Delta C = C_{emitted} - C_{sequestered} = 0

Quick Check

What is the primary role of synthetic biology in a circular bioeconomy?

Think about what happens to waste in this model.

Answer

It allows for the engineering of microorganisms to convert waste products into valuable resources, effectively 'closing the loop' of production.

1. Scientists identified the bacterium Ideonella sakaiensis, which naturally produces enzymes to break down PET plastic. 2. Using SynBio, researchers 'optimized' the genetic code for the enzyme PETase. 3. This engineered enzyme breaks down plastic bottles into their original chemical building blocks (monomers) in days rather than centuries. 4. These monomers are then reused to create new high-quality plastic, preventing the need for new petroleum extraction.

Biofuels and Microbial Fuel Cells

To reduce our carbon footprint, we must move beyond petroleum. Biofuels, such as cellulosic ethanol, are derived from non-food plant matter. Unlike fossil fuels, which release 'ancient' carbon, biofuels release 'modern' carbon that was recently pulled from the atmosphere via photosynthesis. Furthermore, Microbial Fuel Cells (MFCs) offer a radical way to generate electricity. MFCs use specialized bacteria (electrogens) that oxidize organic matter in wastewater. During respiration, these bacteria transfer electrons to an external anode rather than oxygen. The flow of electrons through a circuit generates power:

P = I \times V

where

I

is the current generated by microbial metabolism.

Quick Check

How do Microbial Fuel Cells (MFCs) differ from traditional batteries?

Consider the source of the electrons.

Answer

MFCs use living bacteria to convert chemical energy from organic waste into electricity, whereas batteries use stored chemical reactions.

Imagine a bus running on biodiesel. 1. The plants used for the fuel absorbed

100 \text{ kg}

CO_2

during growth. 2. The processing and transport of the fuel emitted

15 \text{ kg}

CO_2

. 3. Combustion of the fuel in the engine releases

100 \text{ kg}

CO_2

. 4. The net carbon impact is:

(100 + 15) - 100 = 15 \text{ kg added to the atmosphere}

5. While not perfectly zero, this is significantly lower than the

\approx 115 \text{ kg}

net addition from fossil fuels, which have zero sequestration offset.

Mitigating the Sixth Mass Extinction

We are currently facing the Sixth Mass Extinction, driven largely by human activity. Biotechnology provides tools for Genetic Rescue. This involves using CRISPR-Cas9 to increase genetic diversity in small, inbred populations or to confer resistance to diseases (e.g., fungal blight in trees). More controversially, Gene Drives can be used to control invasive species by ensuring a specific trait (like infertility) is inherited by 100% of offspring, eventually collapsing the invasive population. While these tools offer hope for biodiversity, they require rigorous ethical oversight to prevent unintended ecological consequences.

1. The black-footed ferret population was reduced to just 18 individuals, leading to extreme inbreeding. 2. Scientists used cloning (SCNT) to revive a lineage from frozen cells of a ferret that died 30 years ago. 3. By introducing this 'lost' genetic material back into the wild population, they increased the heterozygosity (

H

) of the species. 4. The goal is to reach a level of genetic health where the population can survive environmental shifts:

H_{new} > H_{current}

Key Takeaways

1Synthetic biology enables a circular bioeconomy by turning waste into feedstock via engineered microbes.
2Microbial Fuel Cells (MFCs) generate electricity by capturing electrons from bacterial respiration during waste breakdown.
3Biotechnology can mitigate extinction through genetic rescue, cloning, and gene drives, though ethical risks must be managed.
4The net carbon flux of biofuels is significantly lower than fossil fuels because they utilize 'modern' atmospheric carbon.

Quick Check

Multiple Choice

In a Microbial Fuel Cell, where do the electrons used for electricity come from?

True/False

Biofuels are considered carbon neutral because they do not release any CO2 when burned.

Multiple Choice

Which technology would be most effective for increasing the genetic diversity of a nearly extinct species?

What's Next?

Review Tomorrow

In 24 hours, try to explain the difference between 'ancient carbon' in fossil fuels and 'modern carbon' in biofuels to a friend.

Practice Activity

Research a local invasive species in your area and sketch a plan for how a 'Gene Drive' might be designed to control its population.

Browse

Browse

Biotechnology for Sustainable Development

Learning Objectives

The Circular Bioeconomy

Biofuels and Microbial Fuel Cells

Mitigating the Sixth Mass Extinction

Key Takeaways

Quick Check

What's Next?

Biotechnology for Sustainable Development

Learning Objectives

The Circular Bioeconomy

Biofuels and Microbial Fuel Cells

Mitigating the Sixth Mass Extinction

Key Takeaways

Quick Check

What's Next?