Navigation Links
Modified bacteria turn waste into fat for fuel

HOUSTON (Feb. 28, 2013) "Green" chemistry developed at Rice University is at the center of a new government effort to turn plant waste into fatty acids, and then into fuel.

The Rice lab of bioengineer Ka-Yiu San is part of a recently announced $25 million United States Department of Agriculture project to develop a new generation of renewable energy and bio-based products from switchgrass and forestry residues and from a new hybrid of sorghum being developed at Texas A&M University.

Patent-pending fermentation processes created by San and his colleagues use genetically modified E. coli bacteria to produce fatty acids from hydrolysates. The sugary, carbon-rich hydrolysate is extracted from cellulose, the tough, inedible part of plants that is usually thrown away. San said his lab already gets an 80-to-90 percent yield of fatty acids from model sugars and hopes to improve that over the next few years.

"Adding another 1 or 2 percent doesn't seem like much," said San, based at Rice's BioScience Research Collaborative. "But when you're talking about making several million tons per year, it's huge."

The target products are synthetic diesel and lubricants, according to Ceramatec Inc., a Utah-based company that proposed the project and would produce hydrocarbons from fatty acids that could then be processed by petroleum refineries.

There are two ways to make fuel (from biomass)," said Mukund Karanjikar, innovation manager at Technology Holding LLC, which is administering the project. "You either make alcohols, or you make petroleum-like fuels that can go into current infrastructure. Our program is for infrastructure-compatible transportation fuels.

"There aren't many ways to go from sugars to a diesel-like compound," he said. "The best way is to make fatty acids from the sugars microbially, as many labs have tried to do. But the Rice University process is definitely the winner."

Postdoctoral researchers Xiujun Zhang and Mai Li have been nudging their bacteria toward efficient production of fatty acids for four years, San said. Zhang is responsible for the development of enzymes in E. coli that promote the efficient formation of free fatty acids, while Li, now at GlycosBio, worked to build microbial host strains for high-yield production.

"They have been instrumental to this project," he said. "In four years, with two postdocs, we beat everybody, even groups with dozens of members."

San said the researchers screened hundreds of strains of E. coli and genetically combined the best qualities to reach a high yield. "Other scientists thought we couldn't come close to a maximum yield," San recalled. "They said E. coli only needs to build enough lipid (fat) for its membrane and would stop."

That, as it turned out, was not true. "In fact, one of the strains we developed is very interesting: Instead of excreting the fatty acid, it wants to keep it inside. So more than 70 percent of the weight of these cells is fatty acid. These are obese E. coli," San said.

Since the project began, the researchers have increased their production 100-fold, San said. "We started with a titer of 0.4 grams per liter, and we were excited when we first produced 1 gram. Now we're up to 14 grams per liter and looking at ways to fine-tune the process. But at this point, the bug will not change that much."

Still, it will take time to scale up. "We have to be sure the bug is perfected and robust enough for industry," San said. "Strains that behave well in the lab may not do as well in an industrial setting." He said the development path will involve testing by independent labs to make sure the process is repeatable, and then initial scaling by a pilot plant in two or three years.

"I think this is a very rich area," San said. "When we started this project four years ago, nobody had paid attention to fatty acids. But I knew this would be a good model system with endless variations that could lead to real products."


Contact: David Ruth
Rice University

Related biology news :

1. Genetically modified corn affects its symbiotic relationship with non-target soil organisms
2. Transplanted genetically-modified adipose cells offer potential therapy for liver diseases
3. Circadian rhythms can be modified for potential treatment of disorders
4. Leading evolutionary scientist to discuss how genome of bacteria has evolved
5. Study by UC Santa Barbara researchers suggests that bacteria communicate by touch
6. Team discovers how bacteria resist a Trojan horse antibiotic
7. From scourge to saint: E. coli bacteria becomes a factory - to make cheaper, faster pharmaceuticals
8. Bacterial shock to recapture essential phosphate
9. Disarming disease-causing bacteria
10. Study shows unified process of evolution in bacteria and sexual eukaryotes
11. Invisible helpers: How probiotic bacteria protect against inflammatory bowel diseases
Post Your Comments:
Related Image:
Modified bacteria turn waste into fat for fuel
(Date:11/18/2015)... , November 18, 2015 ... published a new market report titled  Gesture Recognition Market ... Forecast, 2015 - 2021. According to the report, the global gesture ... is anticipated to reach US$29.1 bn by 2021, at ... North America dominated the global ...
(Date:11/17/2015)... 17, 2015 Paris ... --> Paris , qui s,est ... DERMALOG, le leader de l,innovation biométrique, a inventé le ... et empreintes sur la même surface de balayage. Jusqu,ici, ... l,autre pour les empreintes digitales. Désormais, un seul scanner ...
(Date:11/17/2015)... , Nov. 17, 2015 Pressure BioSciences, Inc. ... the development and sale of broadly enabling, pressure cycling ... sciences industry, today announced it has received gross proceeds ... million Private Placement (the "Offering"), increasing the total amount ... or more additional closings are expected in the near ...
Breaking Biology News(10 mins):
(Date:11/30/2015)... Partnership includes an MPP ... the u niversity , s Solid Drug Nanoparticle ... cale - up through cost ... , where licensees based anywhere in the world will have the right to ... Africa , where licensees based anywhere in the world will have the ...
(Date:11/30/2015)... , Nov. 30, 2015 Harvard Apparatus ... a biotechnology company developing bioengineered organ implants for ... notification from The NASDAQ Stock Market that it ... requirements. The letter noted that as a result ... stock having exceeded $1.00 per share for more ...
(Date:11/30/2015)... 2015 Spherix Incorporated (Nasdaq: SPEX ... fostering and monetization of intellectual property, today provided ... designed to create shareholder value. ... "Based on published reports, the total addressable market ... and Spherix will seek to secure fair and ...
(Date:11/30/2015)... , Nov. 30, 2015  Champions Oncology, Inc. (CSBR), ... services to personalize the development and use of oncology ... Executive Officer, will be presenting at the LD MICRO ... Pacific Standard Time (PST).  The conference, held at the ... Angeles, CA , will feature 200 small/micro-cap companies ...
Breaking Biology Technology: