Title: 9.2 Environmental Applications
Course: ATEP - Biotechnology Module B > Section: Extended Learning Applications

9.2.1 Environmental

Environmental Biotechnology is often defined as the integration of science and engineering for the development, use and regulation of biological systems for the remediation of contaminated environments and for the use of environment-friendly approaches to energy and manufacturing.

Renewable Energy Sources

Biotechnology has opened the door to sustainable energy sources unlike fossil fuels, which are limited. Examples are hydrogen harvested from bacteria, and biofuels from fermentation processes.

Hydrogen from Bacteria

Scientists have discovered that some algae (e.g. Chorella) and bacteria (e.g. Clostridium) produce hydrogen under certain conditions. Experiments are underway to find ways to induce these microbes to produce hydrogen efficiently. The first possible widespread use of hydrogen could be as an additive to transportation fuels, as its combination with gasoline to make a 5 percent mixture can reduce nitrogen oxide emissions by 30 to 40 percent in today’s engines.

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9.2.2 Fermentation Products

Fermentation Products

Unlike fuels obtained from petroleum, ethanol (ethyl alcohol) comes the fermentation of biomass such as grains, corns and potatoes. All of these sources are renewable. Ethanol combustion does produce carbon dioxide, but it is more carbon neutral than petroleum products since plants use carbon dioxide to make the fermentable products that are turned into ethanol. Also, compared to gasoline, it is relatively less toxic and burns cleaner. Some of its disadvantages are that its production has been federally subsidized, its current lack of abundance, and its low energy content compared to gasoline.

Biodiesel

It also comes from biomass, mostly from the oils of plant crops, and from recycled restaurant greases, sewage, algae, and animal fats. It is produced by a transesterification reaction using methanol (an alcohol) and plant or animal fats (triglycerides).

A 20 percent biodiesel/80 percent diesel blend can be used in today’s unmodified diesel engines. Unlike other energy sources such as hydrogen or natural gas, it can be distributed in today’s infrastructure of gas stations. Gas stations are making it more available today and a famous singer/songwriter has given its his stamp of approval. He is, in fact, a shareholder in a company that produces the biodiesel product named BioWillie in his honor.

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9.2.3 Remediation

Remediation using biotechnology builds on what “nature” does naturally, the sequestering and breaking down of organisms into the basic building blocks so they can be recycled back into use by “nature.” The treatment of sewage is based on this cycle as well the treatment of oil spills, heavy metal contamination, and other types of contamination. To stimulate degradation by organisms, fertilizer or other supplements are added, especially in the case of large oil spills or contaminants that need to be cleaned up quickly. Bacteria are not the only organisms to be used to clean up contaminants, algae, plants, and trees are also used. When plants are used (Figure 13.26 from textbook), it is known as phytoremediation.

Visit this webpage to learn more. After reading this page, you should be able to: give examples of inorganic pollutants and organic pollutants, define and give examples of phytoremediation, and identify some challenges that still exist in this filed.