Unit 6 - Synthetic Biology for Carbon Dioxide Utilisation Flashcards
How efficient is photosynthesis in converting light to biomass?
Less than 2% efficient.
What is yeast used for?
Preparing a variety of small products such as ethanol (for beer and wine), butanol and GVL.
It also has a large scale use in the food industry such as for baking, making yoghurt and cheese.
What are the features of biocatalysis?
Energy and raw material supply and use of waste is fully integrated.
In some organisms, the individual steps can be controlled so the desired product is formed.
What are some of the problems with fermentation?
Ethical issues on whether the biomass should be used for fuel or food.
The scalability is difficult as to have a very large scale process continuous reactions need to occur rather than batch reactions.
A low concentration of the product is obtained.
What is gas fermentation?
Fermentation that is fed with gaseous feedstock such as CO2, CO, CH4.
What are the benefits of gas fermentation?
It is not dependent on biomass so there is no food vs. fuel debate.
There can be a reduction in carbon emissions. For example, producing ethanol from steel mill off-gas delivers a 87% reduction in life-cycle emission when compared to conventional gasoline.
What are the advantages of using gas fermentation to produce ethanol?
The waste CO2 from the steel industry would provide a secure supply that is circular. This avoids the combustion of off-gas stream which results in a reduction in particulate matter, SOx and NOx emissions by 85%.
Over 40 billion tonnes of ethanol could be made in China and 20 billion tonnes in Europe without using any more carbon.
What happens to the microorganisms after they have been used for fermentation?
They are collected and dried and used to make single cell proteins. This can then be used as a protein source in animal feed.
