BIOTECHNOLOGY AND ENVIRONMENT BY Madam Noorulnajwa Diyana Yaacob PPK Bioproses LECTURE 9

Chapter Contents 1. What Is Bioremediation? 2. Bioremediation Basics 3. Cleanup Sites and Strategies 4. Applying Genetically Engineered Strains to Clean Up the Environment 5. Environmental Disasters: Case Studies in Bioremediation 6. 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