Biofuels have recently emerged onto the market after George W. Bush claimed that America is addicted to foreign oil. The security of the biofuels industry is highly reliant on the vested interest of the government and their ability to procure funding. The laws of economics are steadfast, and biofuels are not an exception. If the cost of production cannot compete with the alternative product, then there will be insufficient demand. Biofuels are a promising alternative to fossil fuels in terms of sustainability and energy independence, but the government has to mandate biofuel use and subsidize its production in order for it to compete in the marketplace. The market will never be able to stand alone without competitively sufficient demand. Scientists need to find the least expensive production configuration by maximizing efficiency at every step of the biofuel production process; which is proving to be more difficult than expected. The following papers are recent publications that probe certain aspects of a critical step in the conversion of lignocellulosic biomass into a fermentable sugar feedstock.
You can hardly turn on the television or radio these days and not hear a discussion about rising gas prices. When most people set out to buy a new car it’s no doubt that fuel efficiency is one of the top benefits they are looking for. A growing number of people also want a vehicle that is environmentally friendly. One approach to try and obtain the best of both worlds is through the production of bio-fuels. There are many different types of bio-fuels, such as bio-diesel, bio-ethanol, or bio-methane, but the one that has stood out the most to me is bio-H2. H2 is one of the most environmentally friendly alternative fuel sources available. The energy content of H2 is a whopping 142MJ/kg, which is the highest of all fuel types currently being used (Fig.1). When ignited, the only byproduct is water… pure water! That sounds like a great overall alternative fuel to me. But there are some draw backs in the current way H2 is made. Currently, 95% of hydrogen production in the United States is dependent on carbon-based non-renewable resources. Not only is this a very expensive process, but it defeats the purpose of it being an environmentally friendly alternative fuel source.
What do you think of when you hear the word algae? I just think of cool looking green stuff that grows in water. But algae have been getting a lot of press lately for being something much more than that! It turns out that these organisms produce a very large amount of lipids that can be converted into biofuel. This is great news considering most of our biofuel (in the form of bioethanol) in the USA is derived from food crops, such as corn. If you recall my blog a couple of months ago, I have already talked about why this isn’t such a good thing. But if you need a reminder, please refer to this cartoon:
So last time I was advocating for 2nd generation biofuels derived from switch grass or wood chips, and while I still believe that is a really great idea and worth pursuing, I have now jumped on the algae bandwagon. You see, algae can be produced on non-arable land, be harvested nearly all year round, has very high photosynthetic efficiencies and (BIG ONE) this already CO2-neutral fuel production can be coupled to CO2 sequestration. Additionally, a wide variety of fuel products can be produced from algae, such as bioethanol, biodiesel and biomethane. And remember, the main problem with using switch grass or wood chips is that thing called biomass recalcitrance… meaning, it is really hard to break down the cell walls and access the energy stored in these plants… but not with algae! Oil content in algae can exceed 80% by weight of dry mass, depending on the species. And while it does take some work to extract that out, the steps are pretty straightforward.
Fossil fuels are disappearing. Carbon dioxide released from burning these fuels is accumulating in our atmosphere. Neither half of this planetary carbon problem has an end in sight.
The immediate solution to Earth’s carbon problem with respect to transportation can be stated as follows: replace fossil fuels with other energy dense fuels that are renewable and either carbon-neutral or carbon-mitigating. The need to power a world’s worth of internal combustion engines leaves us with the stopgap measure of producing biofuels, primarily biologically derived diesel and ethanol. Bio-diesel and ethanol are the products of photosynthetically fixed atmospheric carbon dioxide and, therefore, renewable energy sources. The funny thing is that we humans, not to mention Earth’s animals, also eat lots of products of photosynthetically fixed atmospheric carbon dioxide. Now, with our dinners on the line, we can restate our solution to the global carbon problem in a refined form: replace fossil fuels with carbon-neutral or carbon-mitigating biofuels whose production does not compete with the food supply. Ethanol derived from cellulose-rich biomass is one fuel option that can leave fossil carbon in the ground, remove greenhouse carbon from the atmosphere, power our cars as we drive to the grocery store and leave something on the shelves for us to eat.
Because of the growing demand of energy needs and a lack of efficient, alternative sources of energy, using biotechnology to harvest the hydrocarbons from bacteria or other microorganisms seems to be a feasible operation. That is, of course, barring the innate complexity of metabolism. However, it is only through understanding individual metabolic pathways–inputs, outputs, metabolic intermediates, cross-talk, mechanisms, et cetera–that we can create an organism that will give us what we want (or the zombie plague…♫dun-dun-duuunnnn♫).
The three papers that follow describe an initial presentation of biochemical evidence regarding genes involved in bacterial alk(a/e)ne production and the subsequent two papers will discuss two specific pathways of hydrocarbon production.
The Reiser paper (1), while in a simplistic manner, demonstrates that the Acr1 gene, from Acinetobacter calcoaceticus, is a fatty acyl coenzyme A reductase. The figure to the left is the proposed pathway for wax biosynthesis in A. calcoaceticus. In this proposition, wax synthesis can begin from an acyl-CoA or either an acyl-ACP. This conclusion was made pretty much by making a mutation and observing the appearance/disappearance of bands on a high-tech piece of technology…a TLC plate. This is exciting science. But, like I said, this was one of the first glimpses into the genetics of hydrocarbon production.
As anybody who drives has noticed, the price of oil has increased continuously (except the major drop in late 2008) over the past 15 years, and almost continuously over the past 40 years. This price increase has increased interest in alternative fuels. Biofuels make up one category of these alternative fuels.
Biofuels are broadly defined as any fuel that is derived from a recently living organism. By this definition, biofuels are not new. People have been burning wood and animal fat for thousands of years. Of course, these are not the biofuels being discussed today–unless someone wants to build a car that runs on wood or lard! Usually, modern biofuels consist of alcohols, derived from sugars, starches, and cellulose, or as fatty acid esters (biodiesel), derived from plant lipids (and occasionally animal lipids–like lard!).
On the bench of the 5th Hole at Cedar Rock Disc Golf Course During the 2013 U.S. Masters Disc Golf Championships
For fun relaxation, exercise and competition, I play disc golf. I do it a lot – it keeps me mobile and connected to nature. It’s good to come up on a snake every once in a while and know what to do. I get poison ivy a couple of times a year – it’s an occupational hazard!
My 70-year-old friend Ken also loves the game. I’m perfectly happy to wake up at 5 am, drive halfway across the state to meet up with him then go play at some astonishingly beautiful location. Many stories, I’ll defer.
I’ve been to several U.S. or World championship tournaments. For example, last spring we went to the U.S Masters Disc Golf Tournament in Burlington, NC. At 9 am, on a stunningly gorgeous Saturday morning, we placed ourselves behind the Men (the world champs, over 40) and in front of the Women (same). At each hole, we could watch the men throw monster drives and 50-foot chain-shakers! A plus was that Ken Climo, the Tiger Woods of disc golf, was in the lead pack.
I cannot say that I’m unfamiliar giving presentations in front of groups as I was a TA for years for Dr. Jim Knopp teaching 50+ students for 1.5 hours once a week. I will say that giving my first protein journal club (PJC) presentation was much more nerve wrecking even with a group weighing in less than half of what I am used to. Eyes staring holes into me, waiting to see if I could possibly keep their attention while presenting information on such a controversial topic as biofuels. In the end I would say it was a relatively good success and hopefully this first blog post will produce that same success.
When it comes down to it, most approaches to biofuel production using a microorganism involve extreme genetic engineering to obtain the metabolic products desired. Lu et al (1) demonstrate this by severally re-engineering the E. coli strain X100 to boost its production of medium-chain fatty acids which are of biggest interest in the biofuels/biodiesel community. They do this by knocking out an endogenous acyl-CoA synthetase gene (fadD), inserting a plant thioesterase gene, overexpressing an endogenous acyl-CoA carboxylase and overproduction of an endogenous thioesterase to overcome degradation caused by long chain fatty-acids. This allows for a substantial increase in MCFA, but with an efficiency of only 4.8% (0.048 g fatty acid/g carbon source), there is definitely more optimization to be done.
I went to a small liberal arts college which had a very small chemistry program (some of my classes had just me and one other person). For an elective I was given the choice of either Inorganic Chemistry II class or doing research. I am really good at classwork and only so-so in the lab, plus at that time I was considering going to medical school and didn’t think research was something they were looking for, so I chose the easy route of taking the class. In retrospect, I think doing the research would have been a better choice for me. Not only would I have had more experience, I would have had less self-doubt coming into graduate school.
Dr. Flora Meilleur chaired the 4th workshop on the applications of neutrons scattering in structural biology (BCH590E) hosted by Oak Ridge National Laboratory (ORNL) during June 24-28, 2013. Since the inaugural event in 2010, the workshop has increased in popularity and broadened to include graduate students, post-doctoral fellows and university faculty with diverse backgrounds and interests in structural biology. The workshop is structured to introduce the participants to neutron scattering techniques, instrumentation and data collection, analysis and interpretation and to expose them to cutting-edge research in neutron structural biology. Over 60 graduate students, post-doctoral fellows and university faculty – from 34 premier universities and research institutions across the United States, with no prior neutron scattering experience have now participated.