I'm interested in different cellulose degraders (bacteria, fungi, etc) and want to know how efficient they are. I actully found some interesting cellulose degraders. The JGI (Joint Genome Institute) has started sequencing the bottom mushroom in order to "identify superior enzymes and reactions that could be incorporated into fermentation organisms ".
(http://www.technologyreview.com/Energy/18958/)
I also found another article saying that: "Cytophaga hutchinsoini was originally isolated from sugarcane piles. This microorganism therefore probably produces an array of enzymes allowing it to digest cellulosic substrates. C. hutchinsonii thus represent a rich source of potentially effective cellulase ezymes that can be harnessed for consversio of biomass to simple sugars."
I think that would be interesting to test these natural cellulose degraders and maybe sequence their genes.
I thought it would be cool if I can do a project to genetically engineer a bacteria so it can "breakdown and ferment cellulose biomass directl to ethanol" like the scientists in the article:
Researchers from the Universidad Nacional Autonoma de Mexico have genetically engineered the bacterium Bacillus subtilis to ferment glucose sugar directly to ethanol with a high (86%) yield. This is the first step in their quest to develop bacteria that can breakdown and ferment cellulose biomass directly to ethanol.
In a presentation at last week’s 106th General meeting of the American Society for Microbiology, the team members described their work in engineering the bacterium to produce ethanol as a single fermentation product from the sugars resulting from the breakdown of plant cellulose into simple carbohydrates.
With its very efficient secretion systems, B. subtilis is widely used in the production of extracellular hydrolytic enzymes, but it does not produce ethanol. The researchers engineered in the ethanol production capability by using the pyruvate decarboxylase (PDC) and alcohol dehydrogenase B (ADHII) from Zymomonas mobilis, a bacterium that does produce ethanol.
Initially, the team found that the integration of the ethanol synthetic pathways allowed ethanol production with a 50% yield, but with a large amount of butanediol still produced. Further tweaking avoided the butanediol formation, and bumped the ethanol yield up to 86%.
They found, however, that while the yield was high, the rate of production from the recombinant strains was low. Further work is necessary to increase the rate.
Beyond that, the next step is to engineer the bacterium to produce the cellulase enzymes that can also initially break down the stems and leaves into the simple carbohydrates required for fermentation.
(http://www.greencarcongress.com/2006/05 ... .html#more)
The bio ethanol production field seems very interesting yet challenging too. So far I'm wondering if my ideas are applicable or any suggestion on putting them into an experiment? Please give me some feedback or anything related in this area.
Thank you!
Cici

