Category → Research
Behold the Gribble – a true gutless wonder. The Gribble (pictured here) is a marine wood-boring creature of around 2 millimeters in size. Scientists at the UK’s Biotechnology and Biological Sciences Research Council have been spending quality time with the Gribble because of its exceptional innards.
The tiny animal eats wood that finds its way into the sea. The wood can come from mangrove swamps or wash into estuaries from land. Gribbles, also called ship borers, have also been known to chow on wooden sailing vessels (including, rather famously, those of the Columbus voyages). “I’m sure they’ve taken down a few pirate ships, too” says Simon J McQueen-Mason a BBSRC researcher and materials biology professor at the University of York.
Most critters that eat wood or other lignocellulose plant material rely on symbiotic relationships with a diverse population of gut microbes – called the microbiome – to break down the tough-to-digest meal. When news reports suggest that pandas may hold the key to biofuels breakthroughs because they can live on tough bamboo, it’s really the microbes, and the enzymes made by the microbes, that are of interest.
(You can read a C&EN cover story about pandas, microbiomes and biofuels )
But the Gribble has no microbiome. And it doesn’t have the squishy, absorptive digestive system that most animals have. In fact, it digests its meals of wood in a sterile, hard-sided chamber in its hind gut. McQueen-Mason likens the environment to “a steel container you might use in an industrial lab.”
Instead of microbial helpers, the gribble has a separate organ where it produces the key enzyme itself. Termites do not do this (they have microbes). The gribble “must use quite aggressive chemistry; the enzyme is so harsh that it would kill any microbes” that might otherwise occupy the space, McQueen-Mason says.
The research team found the mystery organ and looked at the genes expressed there. Many of them encoded instructions for making what is called GH7 cellulase. This is a family of enzymes that are normally found in wood-degrading fungi. “These cellulases are abundant but were never reported in an animal before,” McQueen-Mason notes. “We were able to express the genes in a lab fungus and describe the properties.”
They also used X-ray crystallography to discover the structure of the enzyme and show how it binds cellulose chains and breaks them into small sugar molecules.
The Gribble’s enzyme appears to be very rugged and long-lasting, which is a good quality for an enzyme that might be used in an industrial setting to make biofuels from wood or straw, McQueen-Mason points out. It works very well in highly saline conditions and may also function well in ionic liquids. The use of salt water and ionic liquids for biofuels processing may cut down on the use of expensive, precious fresh water. And like a true catalyst, the enzyme may be reusable.
You can see a video of the Gribble – which I highly recommend – it’s kind of cute.
For more on the enzyme, check out the journal paper: ‘Structural characterization of the first marine animal Family 7 cellobiohydrolase suggests a mechanism of cellulase salt tolerance’ www.pnas.org/cgi/doi/10.1073/pnas.1301502110.
The lack of women pursuing science careers has been a perennial hot topic. Unfortunately, scant progress has been observed in spite of a vast amount of effort on many fronts to address this inequality. Earlier this month, a special issue of Nature was devoted to the subject.
Coincidentally, an attempt to unearth possible causes of this disparity was a study published earlier this month in Psychological Science, entitled “Not Lack of Ability but More Choice: Individual and Gender Differences in Choice of Careers in Science, Technology, Engineering, and Mathematics,” by Ming-Te Wang, Jacquelynne S. Eccles, and Sarah Kenny, from the University of Pittsburgh and University of Michigan.
Although I’m likely to give this study short shrift by not going into enough detail, let’s focus on the source material. Here’s the full abstract of the original paper:
The pattern of gender differences in math and verbal ability may result in females having a wider choice of careers, in both science, technology, engineering, and mathematics (STEM) and non-STEM fields, compared with males. The current study tested whether individuals with high math and high verbal ability in 12th grade were more or less likely to choose STEM occupations than those with high math and moderate verbal ability. The 1,490 subjects participated in two waves of a national longitudinal study; one wave was when the subjects were in 12th grade, and the other was when they were 33 years old. Results revealed that mathematically capable individuals who also had high verbal skills were less likely to pursue STEM careers than were individuals who had high math skills but moderate verbal skills. One notable finding was that the group with high math and high verbal ability included more females than males.
Many previous studies by other researchers were cited as motivators behind some of the key questions this study poses. The study contains a number of controls that, to me at least, seem sensible and appropriate: Continue reading →
Cleantech Chemistry HQ got an interesting e-mail yesterday. It stated that Qteros, an industrial biotech start-up of yore, has resurfaced. The firm had officially closed down earlier this year “because of adverse market conditions.”
Qteros’ technology was – and is – based on what the founders call the Q microbe. This critter is a two-in-one biofactory. It chomps down on biomass and also ferments the sugars into ethanol. It seemed that the firm’s microbe was well regarded, but the path to commercialization was murky. Cleantech Chemistry earlier reported that the firm was regrouping and maybe looking for a buyer.
That buyer, it turned out, was to be three of the company’s original founders. The firm was a tech spin off of the U. of Mass. Amherst. Original COO – and now CEO – Stephan Rogers of Amherst says “Having examined all the research, we now see an immediate pathway to commercialization with the current technology. The company is going to pursue a new and different, less capital-intensive business model. Part of our strategy to quickly get to market is to partner with others who have deep experience in microbial research to help us jump-start the process.”
Also at Amherst and still on the company’s scientific advisory board is Susan Leschine, who discovered the Q microbe. Qteros’ connection to the school will remain very cozy, it appears from the press release. It seems that the developers will move in with fellow researchers and will not seek out their own lab or office space until sometime in mid 2013. So it may be a little while before we hear more about the road forward.
It’s not too often that I get a press release with a New Zealand embargo time. Waste gas to fuels and chemicals firm LanzaTech got its start in New Zealand, but is currently headquartered in Illinois. Still, the company’s larger projects are all in Asia, and being on the opposite side of the world from Cleantech Chemistry blog HQ is not a problem for them.
Yesterday (which is today in New Zealand), LanzaTech CEO Jennifer Holmgren spoke to a conference of oil refiners in New Delhi. In her remarks, she announced that the firm has a new joint development agreement with Malaysia’s national oil company Petronas.
The two firms will work to produce chemicals from carbon dioxide – the first one being acetic acid. LanzaTech already has two facilities that make ethanol from CO. In all cases, the CO or CO2 comes from waste gases. LanzaTech’s proprietary microbes ferment the gas into various end products. The Petronas deal will get its CO2 from refinery off gases and natural gas wells.
Earlier this year, the venture arm of Petronas contributed to LanzaTech’s third round of venture funding. And it seems the two companies have been in cahoots ever since.
C&EN profiled LanzaTech this summer.
And there is another cleantech firm that aims to make acetic acid – Zeachem. Zeachem is building out its plant that will produce acetic acid – as well as ethanol – from hybrid poplar grown in Oregon.
As has been reported at C&EN and elsewhere, the anxiously awaited 2012 Nobel Prize in Chemistry was awarded Wednesday to Robert Lefkowitz and Brian Kobilka for their work characterizing the structure and function of G-protein-coupled receptors (GPCRs).
Here at CENtral Science, giddy Nobel fan boy David Kroll has followed up with two terrific posts (and promises yet another) about this year’s award, and Carmen Drahl, in the context of discussing a researcher’s two “families,” conducted an insightful interview with author Cheryl Renée Herbsman, daughter of Robert Lefkowitz.
The impact of this research cannot be overstated. GPCRs are huge, no question. Easily half the projects I’ve worked on in my career as a medicinal chemist have targeted GPCRs, and many of those that did not still contained one upstream or down in a broader signalling cascade.
In spite of the importance of this research, there has been some complaining about this year’s chemistry Nobel, and others given in recent years. The injured parties argue that the chemistry award is being somehow sullied by including work that isn’t really chemistry—by an overly strict definition. Last year’s award, which was for discovery of quasicrystals by Dan Shechtman, was also criticized by some because it didn’t go to a “real chemist.” This attitude even caught the attention of Nobel laureate Roald Hoffmann, who viewed the Nobel Committee’s recent decisions “as a call to our profession to embrace the far and influential reach of chemistry.”
In the chemistry blogosphere, there were several calls to abandon this chemistry-purist attitude, including a very nice rebuke by Derek Lowe, who succinctly stated, “Biology isn’t invading chemistry – biology is turning into chemistry.” Derek went on:
And that’s the story of molecular biology for you, right there. As it lives up to its name, its practitioners have had to start thinking of their tools and targets as real, distinct molecules. They have shapes, they have functional groups, they have stereochemistry and localized charges and conformations. They’re chemicals.
In his blog, Chemjobber granted this argument, but is still uncomfortable with the notion. He wrote, “My main complaint against this trend of biology/biologists winning recent chemistry Nobel prizes is that it is beginning to distract from the non-life-sciences aspects of chemistry.”
I mention all this grumbling about the Nobel Prize in Chemistry because a topic covered by this blog is so-called nontraditional careers in chemistry. So far be it from me to criticize the awarding of a Nobel Prize in Chemistry to chemistry research that some may view as nontraditional.
Breakthrough scientific research often occurs at the boundaries of disciplines. A key insight can be made by someone skilled in another field of science as they view an intractable problem from a previously unappreciated perspective.
Those of us who get worked up over media hysteria regarding things containing chemicals (the horror!) and are deeply critical of consumer products described as “chemical free” have long maintained that everything is made of chemicals. True enough. If so, then we can hardly complain if a Nobel Prize in chemistry is awarded for work in biology, because—repeat after me—biology is chemistry. And as David Kroll rightly pointed out, the tools necessary for elucidating the function of the earliest-understood GPCRs were chemical tools.
This is really nothing new. I’ve heard many times in my career that “all biology is chemistry, and all chemistry is physics.” So…maybe there’s some room in the physics Nobel for some chemistry research? If that happens, will physicists grumble that their Nobel didn’t go to a “real physicist?”
[With a note on some confusion about wheat, and if it has been genetically modified (see below)]
The herbicide 2,4 D is pretty powerful stuff. It has recently been in the news because it kills weeds that have developed resistance to glyphosate (brand name Roundup). In May, I wrote about efforts by Dow AgroSciences to bring a new genetically modified corn to market that has been engineered to be tolerant to 2,4 D.
The idea is that the new corn would withstand applications of both glyphosate and 2,4 D, and that farmers would use those two herbicides, and presumably a rotation of at least one other chemical control, to kill weeds and prevent new occurrences of resistant weeds.
Along with the new corn, Dow scientists created a new version of 2,4 D, called 2,4 D Choline, that is less likely to drift off the fields where it has been applied. Now, one group of growers, the Save Our Crops Coalition, has issued a joint statement with Dow saying that the information Dow has supplied about reduced drift and volatility, along with the company’s pledge to investigate non-target claims, has gone a long way to satisfy its concerns about migrating herbicide. Both SOCC and Dow say they have “agreed to modify positions with respect to pending regulatory matters around 2,4-D tolerant crops.”
Prior to this agreement, the Save Our Crops Coalition had used the USDA’s open comment period to request an environmental impact statement to assess the likelihood of drift from 2,4 D applications.
They pointed out that since not all farmers will be growing 2,4 D tolerant crops, drift to non-intended targets could result in significant crop damage, since it would be applied during the growing season (imaging a field of vegetables that got smogged by 2,4 D – the plants would croak along with the weeds).
I reported on Dow’s work to reduce migration of 2,4 D in the C&EN feature story. Here’s the relevant background:
David E. Hillger, an application technology specialist at Dow AgroSciences, explains that rather than traditional ester or amine forms of the molecule, which can volatilize in the environment, the new version is a more stable quaternary ammonium salt.
In addition, Hillger says Dow’s proprietary manufacturing process produces a product with less particle drift when application directions are followed. Dow recently reported that field tests of the formula showed a 92% reduction in volatility and a 90% reduction in drift.
Crops that contain the 2,4-D tolerance- trait will also tolerate older versions of 2,4-D. However, Dow has developed a stewardship program that obligates farmers to use a premixed combination of 2,4-D choline and glyphosate. The program includes farmer education about using multiple herbicide modes of action, the requirement to use Dow’s new herbicide mixture, and labeling instructions for proper application. State pesticide regulations generally require farmers to follow labeling guidelines when using herbicides.
For now DowAgrosciences is waiting on regulatory authorizations for 2,4-D tolerant corn, but the company says it plans to get the green light in time for the 2013 growing season.
Certainly there are other criticisms of the 2,4 D-tolerant crops still out there. One important concern is that farmers may use chemical fertilizers in such a way as to promote even more herbicide-resistant weeds – ones that cannot be killed with 2,4 D or glyphosate. Another is the possibility that the amount of 2,4 D used on crops will dramatically increase (glyphosate, though used in large amounts, breaks down rather quickly in soil).
And of course, foes of all types of GMO crops abound, and anyone who is against Roundup Ready corn is not likely to be in favor of the new varieties.
Speaking of which, I’ve noted a number of commentaries relating to wheat lately, apparently due to the rise of anti-gluten eating. Many leave the reader with the impression that the U.S. is awash in genetically modified wheat. This is incorrect – there are many wheat hybrids on the market today, but none have been genetically engineered.
I find it handy to refer to an online USDA list – updated seemingly daily – which lists pending GM crops as well as those that have been approved already (in the section titled Determinations of Nonregulated Status). You may want to bookmark it, or have it printed on handy cards to give to people.
Sometimes when you dig a little on Google News you find fascinating nuggets in local news of the topics that we cover here at C&EN. A great example is in Knoxville’s alternative newsweekly Metro Pulse.*
Newshound Joe Sullivan digs into what ever became of $70 million that the state of Tennessee spent in the flush days of 2007 to start up a switchgrass and cellulosic ethanol industry in the state.
The good news on the project is that the promised 250,000 gal per year cellulosic ethanol plant did open, in Vonore, Tennessee. The bad news is that it has not been using any of the switchgrass grown on 5,000 surrounding acres. The switchgrass part of the project involved the University of Tennessee Institute of Agriculture. The state figured switchgrass would grow great there. And it seems to have been correct.
Sullivan reports that more than half of the $70 million project money went to build the pilot plant. But corporate partner DuPont (now DuPont Cellulosic Ethanol) has used the pilot plant to test and demonstrate its ability to make ethanol from corn stover. Corn stover is a feedstock that is available in huge quantities…. in Iowa. As it happens, DuPont’s first commercial-scale cellulosic ethanol plant is in Nevada, Iowa, and is set to come online soon.
C&EN has mentioned the Vonore plant a half dozen times (including in a previous post on this blog). The move away from switchgrass escaped our attention, but it is an important development for the UT folks and the farmers they have been working with.
So what will happen to the 50,000 tons of switchgrass that were harvested by Vonore-area farmers? Read the story to find out.
* Edited 8/28 to correct reference to Metro Pulse
It’s been a very busy summer, but I had a chance to catch up with Rick Eno, the CEO of Metabolix, last week. Metabolix makes a bio-based plastic that it calls Mirel, though chemists call it a polyhydroxyalkanoate polymer (PHA). We last heard from Metabolix in January when its commercial-scale partnership with Archer Daniels Midland dissolved.
The breakup was a significant blow to the company in terms of growing its business and selling Mirel to customers. The partnership with ADM was based around an ADM-financed production plant capable of making 50,000 tons of Mirel per year. Unfortunately, sales ramped up slowly and ADM said the market was too risky.
Since the breakup, Metabolix has decided to launch the biodegradable Mirel bioplastic under its own nameplate, says Eno. It has transferred inventory from ADM, and brought over all the business operations. Still, the company needs a production partner.
“Since Mirel was exclusive to ADM for so long, [after the breakup] we did get inbound calls and we also reached out to potential partners to establish potential manufacturing,” Eno told C&EN. He says that rather than try to sell enough Mirel to keep a huge plant busy, he’s now looking for something closer to a 10,000 ton per year scale.
“We’ve narrowed down a large number of potential opportunities to four. Now we’re looking at engineering detail for integration of our manufacturing technology to the partners’ asset sets,” Eno reports. “We’re deeply evaluating a short list of manufacturing options.” Without ADM to center the business, Metabolix can look outside the U.S. – for example, to be closer to customers. In fact, the firm has opened a sales office in Cologne, Germany to be close to the European market.
As Alex Tullo wrote in his recent cover story on biodegradable plastics, an important market niche is in organic waste handling – specifically in municipalities where organic waste is separated and hauled to composting facilities. Eno suggests this is both a good niche for PHA, and also a great reason to be in Europe where people rigorously sort their trash.
Eno followed up on his January comments that the company would look to higher-value markets that really require biodegradability, rather than try to compete with cheap and plentiful petro-based plastics. He said the company is focusing on agriculture and horticultural markets – for things like biodegradable plastic mulch; the consumer market for compostable bags and similar products for organic waste diversion; a broader packaging market; and a marine and aquatic segment where it is important that plastics biodegrade fully in oceans and streams.
The breakup with ADM somewhat ironically boosted Metabolix’s cash position (for some rather complicated accounting reasons). That will be a big help, because the company is still developing its upcoming portfolio of bio-based C3 and C4 chemicals, using different PHA molecules than Mirel uses as an intermediate. Example target chemicals are gamma butyrolactone and acrylic acid. The C4 program is the farthest along and has reached 60,000 liter fermenters in scale-up. Eno says the chemicals program has netted “significant partner interest.”
Also helping to pay the bills is a government grant backing the company’s efforts to put the bio-based plastic platform into purpose-grown plants. In a recent advance, Metabolix and its research partners have reported a new way to increase polyhydroxybutyrate (PHB) production in sugar cane.
So there you have it – Metabolix is still moving along. The next time we will hear from them, Eno says, it will be because they have a new production partnership to announce. Stay tuned.