Environmental Protection Essential Idea: Biotechnology can be used in the prevention and mitigation of contamination from industrial, agricultural and municipal wastes.

2 TOK  Emergent properties are the outcome of the interaction of the elements of a system. In what context is a reductionist approach to science productive and in what context is a reductionist approach problematic?

Bioremediation  In response to environmental pollution incidents, various methods of cleanup can be employed.  Bioremediation  Physical and Chemical procedures.

4 Bioremediation  Various physical and chemical means are often used to clean up a polluted area.  Detergents  Pressure washers 4

5 Bioremediation  Physically scrubbing polluted areas with chemicals can also be used during clean up.

6 Use of Microorganisms  Microorganisms are often used in bioremediation.

Bioremediation--How it Works  Generally, some toxic substance is spilled into the environment.  The waste kills most bacteria, but a few survive.  The bacteria which survive can be cultured and used to break down the waste.  Bacteria can also be engineered to break down the waste by inserting the correct gene/plasmid into the genome of the bacterium.

9 Bioremediation  The bacteria may change the waste into something less toxic, into smaller parts, or break it down completely.

10 Bioremediation-Examples:  When oil is spilled, it poses many challenges for cleanup.  Benzene and other types of polycyclic aromatic compounds are found the spill.  The tendency for the oil to bind tightly to soil particles poses challenges for cleanup.  It throws off the carbon- nitrogen balance and hinders microbial growth.

11  Certain genera of bacteria, such as Marinobacter and Pseudomonas are often used in the cleanup efforts.  Marinobacter hydrocarbonoclasticus is a genus of proteobacteria found in sea water and readily degrades oceanic oil spills which often included aromatic compounds like benzene. Bioremediation-Examples: Both images: 14_at_ _AM.pnghttps://microbewiki.kenyon.edu/index.php/File:Screen_shot_ _at_ _AM.png

12  Some members of the Pseudomonas genus such as Pseudomonas aerugnosa and P. putida are used to metabolize hydrocarbons found in oil spills. Bioremediation-Examples: 2&catid=140:analytical-services&Itemid=132

13  Methyl mercury is a common environmental pollutant from industry and can be broken down by many Pseudomonas species such as P. putida. The remaining mercury can be collected and removed from the environment. Bioremediation-Examples:

14 Biofilms  According to the IUPAC, a biofilm is an aggregate of microorganisms in which cells that are frequently embedded within a self- produced matrix of extracellular polymeric substance (EPS) adhere to each other and/or to a surface.  EPS is a sugary, molecular strand that helps to develop complex 3D structures. This makes the biofilm stronger and enables it to survive.

15 Biofilms  Biofilms possess emergent properties:  Initial attachment:  Growth:  Irreversible attachment:  Maturation I:  Maturation II:  Dispersion:

16 Initial Attachment  The formation of a biofilm begins with the attachment of microorganisms to a surface.  Initially these attachments are weak and reversible, due to Van der Waals interactions.

17 Irreversible Attachment  Later the attachment becomes more permanent as bacterial structures such as pili get involved in the attachment.

18 Maturation I  Cells of the biofilm communicate with other cells via quorum sensing.  Quorum sensing is known to be involved in the formation of a biofilm in numerous bacterial species.

19 Maturation II  Once colonization has begun, the biofilm grows through cell division and recruitment of other bacteria.  Most biofilms are diverse mixtures of many species of bacteria, fungi, algae, yeasts, protozoa, and many other microorganisms.

20  Additionally, this stage is also characterized by the growth of polysaccharide matrices and inclusion of materials from the surrounding environment.  These matrices act as an enclosure for the biofilm and increase the resiliency of the structure. Maturation II

Dispersion  Dispersion is the final stage of the formation of a biofilm.  During this stage, the biofilm is well established and only changes in shape and size.  This stage allows the colony to spread to new surfaces.

Ubiquity of Biofilms  Biofilms are ubiquitous, and are very important to the health and well being of the economy, and the people who live in it.  Biofilms cost our economy billions of dollars each year.  Energy loss  Equipment damage  Product contamination  Medical infections

23  Microorganisms growing in a biofilm are often highly resistant to antimicrobial agents.  Biofilms have properties that differ quite a bit from the free-floating bacteria that comprise them.  The dense extracellular matrix and outer layer of cells acts to protect the cells in the interior.  Horizontal gene transfer between organisms facilitates a stable, more resilient biofilm. Ubiquity of Biofilms

24  Not all biofilms are more resistant to antimicrobials.  Some biofilms show just as much susceptibility to antimicrobial agents as free-floating bacteria. Ubiquity of Biofilms

25 Biofilms in Bioremediation  Biofilms offer a huge potential for helping to clean up environmental damage, hazardous waste clean up, and wastewater treatment.

26 Biofilm and Wastewater Treatment  Biofilms play an important role in wastewater treatment.  Trickle filter beds are often built to facilitate the formation of a biofilm.  The biofilm feeds off of the nutrients in the waste stream.

27 Environmental Problems and Biofilms  For all the good that biofilms do, there are many problems they can cause.  They can clog or corrode pipes.  They can contaminate surfaces of food production facilities.  They can contaminate waterways through the transfer of ballast water from ships.