How to brew a food friendly biofuel
How to make it friendly??
There is a need for alternative sources of energy which do not use up natural resources or harm the environment. There are different types of renewable energy ranging from: hydro-, nuclear, wind, solar, geothermal and hydrogen. One possible way to generate energy is to use plants, biomass or agricultural residues, which is also known as biofuels. Fermentation is a versatile process, which can be used to produce not only beer, but also biofuels such as bioethanol.
Bioethanol is mainly produced by fermentation of sugar in yeast cells. Different types of sugars can be provided for the cells to grow and produce alcohol. The number and size of yeast cells affects the amount of bioethanol produced, and this is overall highly dependent on the quality of the feedstock. Crops such as wheat and grain are simple for cells to use and break down as they possess simple sugars. However, there are ethical issues with using food crops to make fuel. On the other hand, non-food crops such as seaweed and woody plants can be used instead, however their complex cell sugars require enzymes to convert this into a form yeast can use.
To solve this, Biochemical Engineers have started to look to nature to find new enzymes that can break down these complex nutrients. This search has led to the discovery of microbes in the stomachs of sheep that can digest seaweed; worms called gribbles which can digest wood; and Antarctic salps that can digest algae. By isolating these enzymes and putting their genes into yeast, we can give them the ability to use and ferment these complex feeds. This is a great example of Nature-Inspired Engineering which aims to draw lessons from nature to engineer innovative solutions.