Biofuels Flashcards
What are biofuels?
These are a renewable liquid or gaseous fuel made by and/or from living organisms or the waste that they produce.
What % and directive of transport fuel to be made from renewable energy sources?
10% by 2020l EC Renewable Energy Directive 2009
What is Bioethanol produced from?
Sugar beet, sugar kane and corn.
Fermentation of soluble sugars by the yeast Saccharomyces Cerevisiae.
What is Biodiesel produced from?
From the extraction of the oil from crops such as soybean, oilseed rape and oil palm followed by chemical esterification.
What enzyme in the yeast converts sucrose to glucose and fructose ?
intertase.
How many ATP molecules does yeast produce in glycolysis.
2 ATP for each glucose - leads to an increase in biomass.
What is the function behind the bioengineering of yeast to allow for a reduction in ATP yield?
High ATP - Increase in biomass (waste in carbon and energy resources could have been used towards ethanol)
DIVERT metabolic flux into ethanol not ACETATE.
Give an example of a microorganism used in Bioethanol production:
Zymomonas Mobilis - anaerobic, GN
Breaks down bacteria via Entner Dourdoroff
What is wanted in the production of Bioethanol?
A reduction in ATP, this is why Z.mobilis is used 2 pyruvates + 1 ATP for each glucose molecule.
Z.mobilis can withstand higher ethanol levels then S.cere
What is a limiting factor associated with using Z.mobilis for Bioethanol production?
It can only use a few simple sugars for ethanol production - limit it.
Can E.coli be used to produce Bioethanol?
Not naturally, but through bioengineering it can developed to produce fatty acid ethyl esters for Biodiesel.
What genetic engineering is needed alongside S.Cerevisiae to convert glucose to ethanol (Bioethanol)?
Needed to convert into ethanol not oxaloacetate or acetate.
What is used in the production of Biodiesal?
Fatty acid methyl and ethyl esters.
What types of microorganisms can be used in the microbial production of biodiesel?
Yeasts such as S.Cerevisiae and some algae can accumulate fatty acids such as triglycerides, cannot be used directly as fuels. (can be engineered to divert lipid synthesis)
E.coli (can be engineered to produce fatty acid ethyl esters)
Which algae produces glycerol, a potential feedstock?
Dunaliella.
What is an example of first gen biofuels?
These are made from edible crops.
What are examples of 2nd and 3rd gen biofuels?
These are produced from non-food crops or plant waste.
What is plant biomass composed of?
Cellulose, hemicellulose and lignincellulose
Which plant biomass type makes up the the majority of the biomass in the world?
Lignincellulose.
How is plant cellulosic material broken down into 5- and 6- carbon sugars?
Physical and chemical pretreatment.
Enzyme exposure from biomass-degrading organisms (cellulase)
Where are microbes that naturally produce cellulase from?
Volcanic soil, termite guts and cow stomachs.
What are the current goals for the future of Biofuels?
- Scale up production of microbial cellulases.
- Engineering yeast for higher ethanol tolerance.
- Gen modify m/o to use more sugars and ferment more efficiently
- Get microbial strains to make products such as biobutanol
- Algae ; Biodiesel Production
