BIOTECHNOLOGY AND ENVIRONMENT

BYMadam Noorulnajwa Diyana Yaacob

PPK BioprosesLECTURE 9

Chapter Contents

1. What Is Bioremediation?2. Bioremediation Basics3. Cleanup Sites and Strategies4. Applying Genetically Engineered Strains to

Clean Up the Environment5. Environmental Disasters: Case Studies in

Bioremediation6. Future Strategies and Challenges for

Bioremediation

What Is Bioremediation?

Biodegradation - the use of living organisms such as bacteria, fungi, and plants to degrade chemical compounds

Bioremediation – process of cleaning up environmental sites contaminated with chemical pollutants by using living organisms to degrade hazardous materials into less toxic substances

What Is Bioremediation?

Initiative of the U.S. Environmental Protection Agency (EPA)

To pollution due to chemical dumping and storage

Purpose is to clean up hazardous waste sites

What Is Bioremediation?

Why use bioremediation? To convert harmful pollutants into relatively

harmless materials such as carbon dioxide, chloride, water, and simple organic molecules

Processes are generally cleaner

What Is Bioremediation?

Biotechnological approaches are essential for; Detecting pollutants Restoring ecosystems Learning about conditions that can result in

human diseases Converting waste products into valuable

energy

Bioremediation Basics What needs to be cleaned up?

Soil, water, air, and sediment Pollutants enter environment in many

different ways Tanker spill, truck accident, ruptured chemical

tank at industrial site, release of pollutants into air

Bioremediation Basics

Bioremediation Basics

Chemicals in the Environment Carcinogens

– Compounds that cause cancer Mutagens Cause skin rashes, birth defects Poison plant and animal life

Bioremediation Basics

Bioremediation Basics

Fundamentals of Cleanup Reactions Microbes convert chemicals into harmless

substances by either Aerobic metabolism (require oxygen) or anaerobic

metabolism (do not require oxygen) Both processes involve oxidation and

reduction reactions Oxidation – removal of one or more electrons from an

atom or molecule Reduction –addition of one or more electrons to an

atom or molecule

Bioremediation Basics

Bioremediation Basics

Aerobic and Anaerobic Biodegradation

Bioremediation Basics

Metabolizing Microbes Indigenous microbes – those found naturally at a

polluted site Bacteria

Pseudomonas E.coli

Algae and fungi Phanerochaete chrysosporium Phanerochaete sordida Fusarium oxysporum Mortierella hyaline

Bioremediation Basics

Stimulating Bioremediation Nutrient enrichment (fertilization) – fertilizers

are added to a contaminated environment to stimulate the growth of indigenous microorganisms that can degrade pollutants

Bioaugmentation (seeding) –bacteria are added to the contaminated environment to assist indigenous microbes with biodegradative processes

Cleanup Sites and Strategies Soil Cleanup

Ex situ bioremediation Slurry phase bioremediation Solid phase bioremediation

Composting Land farming Biopiles

In situ bioremediation Bioventing – pumping either air or hydrogen peroxide into

the contaminated soil

9.3 Cleanup Sites and Strategies

Cleanup Sites and Strategies

Bioremediation of Water Wastewater treatment Groundwater cleanup

Wastewater treatment

It is a well known application of bioremediation

The purpose is to remove; Human sewage

fecal material paper wastes

Soaps Detergents Other household chemicals

Wastewater treatment

House septic systems and municipal wastewater treatment facility use bioremediation

Human sewage from residential house

Cleanup Sites and Strategies

Cleanup Sites and Strategies

Cleanup Sites and Strategies Turning Wastes into Energy

Methane gas used to produce electricity Soil nutrients can be sold commercially as

fertilizers Anaerobes in sediment that use organic molecules

to generate energy Electicigens – electricity-generating microbes

Applying Genetically Engineered Strains to Clean Up the Environment Petroleum-Eating Bacteria

Created in 1970s Isolated strains of pseudomonas from

contaminated soils Contained plasmids that encoded genes for

breaking down the pollutants

9.4 Applying Genetically Engineered Strains to Clean Up the Environment E. coli to clean up heavy metals

Copper, lead, cadmium, chromium, and mercury Biosensors – bacteria capable of detecting a

variety of environmental pollutants Genetically Modified Plants and

Phytoremediation Plants that can remove RDX and TNT

Environmental Disasters: Case Studies in Bioremediation Jet Fuel and Hanahan, South Carolina The Exxon Valdez Oil Spill Oil Fields of Kuwait

Future Strategies and Challenges for Bioremediation Recovering Valuable Metals Bioremediation of Radioactive Wastes