Assignment 1 : Steven Ness : HTGAA23

Engineering microorganisms to aid in perchlorate bioremediation.

Perchlorate is a chemical ion with the formula ClO4- that is found naturally on earth in some locations in low concentrations and ubiquitously in high concentrations (0.5%-1%) on Mars. It is also a commercially produced chemical mainly used as oxidizers for rocket propellant and pyrotechnic devices. Perchlorate has been found to have adverse effects on human health, particularly on the thyroid gland, which is why it has been regulated by some countries and organizations, including the U.S. Environmental Protection Agency (EPA).

Perchlorate can be naturally degraded by certain bacteria that are capable of using it as a source of energy and reducing it to chloride ions in a process called perchlorate reduction. Perchlorate reductase is an enzyme that takes perchlorate or chlorate and a reduced electron acceptor and produces chlorite, water and an oxidized electron acceptor. Chlorite dismutase is a second enzyme that takes this chlorite and coverts it into O2 and Cl-, using a process that is only now being elucidated.

1) Describe a biological engineering application or tool you want to develop and why.

Currently, bioremediation of perchlorate is done using naturally occurring anerobic bacteria that use perchlorate as an electron acceptor in respiration. These bioremediation efforts are typically performed in bioreactors and are one of the main ways to remediate soil contanimated by perchlorate.

We propose to attempt to transfer these genes to a fungus, and then to upregulate these genes so that they are able to degrade perchlorate in the environment. Potentially the fungus could be used in situ as a way to perform composting or for soil remediation.

2) Describe one or more policy goals related to ensuring that this application or tool contributes to an “ethical” future, like ensuring non-malfesance (preventing harm). Break big goals down into two or more specific sub-goals.

One important policy goal related to this application would be that it would not be harmful to organisms or the environment. There are many aspects to this broad policy goal, some of the relevant factors are listed below:

• use of non-hazardous bacteria
• predictability
• does not harm existing bacteria by out competing them
• containment of GMM bacteria
• tracking mechanism
• stopping mechanism

Another policy goal would be to educate the public about the risks and possible benefits of this solution. Historically releasing GMMs into the environment was contraversial, and allaying the fears of the public and regulators would be an important part of this strategy. Some aspects to be considered would be:

• Educating the public about this project
• Listening to the concerns of the public
• Addressing their concerns