News and Trends

Amyris is now partnering with Brazilian airline GOL to begin the first international commercial flight with the recently approved biojet fuel, farnesane.

GOL has committed to fly its Boeing 737 fleet with up to a 10 percent blend of the renewable fuel on its U.S. to Brazil routes starting this month. Amyris' efforts to bring farnesane-based biojet fuel to commercial airlines are supported by Boeing, the Inter-American Development Bank and other partners.

"We at Amyris are thrilled that GOL will be using our renewable jet fuel blend for their flight route from the United States to Brazil, the first of what we expect to be many routes with the world's leading airlines," said John Melo, president and CEO of Amyris.

"We are working closely with the Brazilian Biojet Fuel Platform to achieve the 1 percent blend milestone in early 2016, beginning with more than 200 sustainable flights during the World Cup in Brazil." said Pedro Scorza, director of technical operations with GOL.

Amyris says farnesane can reduce greenhouse gas emissions by up to 80 percent on a lifecycle basis compared to traditional fuels.

The Petrixo Oil & Gas has selected the green fuels technology of UOP LLC, a Honeywell company, to produce biojet fuel and renewable diesel in Fujairah, United Arab Emirates.

Petrixo, a Dubai-based company, will use the UOP technology to process around 500,000 metric tons per year of renewable feedstocks into biojet fuel and renewable diesel, trademarked as Honeywell Green Jet Fuel and Honeywell Green Diesel, respectively. The technology is flexible and is capable of processing a variety of renewable feedstocks including oils from algae and halophytes.

Petrixo will invest $800 million to build a new facility designed to produce 1 million tons per year of biojet and renewable diesel products. Honeywell says this will be the first commercial-scale production facility outside in North America.

According to Eid Al Olayyan, CEO of Petrixo Oil & Gas, "Petrixo believes that new energy solutions are immensely important for scalable, environmental and renewable solutions. UOP's green fuels technologies are proven refining solutions that produce high-quality products compatible with petroleum-based fuels."

Honeywell Green Jet Fuel, which is blended up to 50 percent with conventional jet fuel, can reduce greenhouse gas emissions by 65 to 85 percent compared with petroleum-based fuels. and Baum and Associates recently compiled data of car sales and found that clean diesel car sales in the United States have increased by 25 percent during the first six months of 2014.

The 2014 clean diesel total sales includes six months of consecutive sale increases, including double digit increases in March, April and May. June 2014 was the 43rd month of increase in clean diesel sales in the past four years.

"Sustained and mostly double-digit increases in sales each month over a four year period prove that U.S. consumers are embracing the benefits of clean diesel technology and its proven, high fuel efficiency, great driving performance, and long-term value," said Allen Schaeffer, the Executive Director of the Diesel Technology Forum.

Research and Development

Lactobacillus species are the predominant contaminants during fermentation that decrease the profitability of biofuel production. Current antibiotic treatments against these contaminants have led to emergence of drug-resistant bacterial strains. Researchers from the National Center for Agricultural Utilization Research Service of the US Department of Agriculture in Peoria, Il, led by Piyum A. Khatibi published the result of their studies on a new, non-antibiotic, eco-friendly strategy against bacterial contamination.

Two genes, LysA and LysA2, from bacteriophage were individually expressed in Saccharomyces cerevisiae. These genes produce enzymes that are capable of breaking down common Lactobacillus species that contaminate fermentation. Reductions in Lactobacillus population in the infected fermentations with yeast expressing LysA or LysA2 were observed in just under 72 hours. Lactic acid and acetic acid levels were also reduced in all infected fermentations suggesting less contamination in fermentations with transgenic S. cerevisiae compared to those with untransformed yeast.

These results demonstrate the feasibility of using yeast expressing bacteriophage endolysins to reduce L. fermentum contamination during fuel ethanol fermentations.

Cellulose, the most abundant biomass on earth, is commonly degraded by cellulases from microorganisms. Trichoderma reesei has been explored for cellulase production. However, it has low beta-glucosidase activity, which is vital in cellulose hydrolysis. Guangxi University researchers in China led by Jia-Xun Feng isolated new fungal strains from forests in China hoping to discover a strain which can be used to improve commercial cellulase. The study was published in Biotechnology for Biofuels.

Out of 305 fungal strains from China, 31 strains were found to have decent cellulase activity; 18 of these were Trichoderma while 13 were Penicillium species. The best-performing isolate was the Trichoderma koningiopsis FCD3-1, which had similar cellulase activity to Trichoderma reesei Rut-C30, but exhibited high beta-glucosidase activity. It retained 90% of its activity after 360 hours at pH 4.0 and 30C, which are optimal conditions for producing ethanol from cellulose. 

T. koningiopsis FCD3-1 was the most efficient producer of cellulase, and also produced a high level of beta-glucosidase, indicating its potential application in bioethanol production.

Glycerol-3-phosphate, a glycerol, is formed through a pathway initiated by glycerol-3-phosphate dehydrogenase (GPDH). Recently, this GPDH was found in the microalgae Phaeodactylum tricornutum, making it as a potential ideal material for biodiesel and bioactive compounds. Now, researchers led by Hong-Ye Li from the College of Life Science, Jinan University in China look into its potential use for commercial production of bioproducts.

GPDH gene was overexpressed in transgenic P. tricornutum. This resulted in an increase in glycerol concentration in the transgenics compared with the wild type. This suggests that overexpression of GPDH promoted the production of glycerol-3-phosphate. There was also an observed 60% increase in neutral lipid content.

GPDH had a significant impact on numerous metabolic processes in diatom cells, including the biosynthesis of glycerol and neutral lipids. These results suggest that metabolic engineering of these microalgae will benefit biofuel production.

Biofuels Processing

2,3,5,6-Tetramethylpyrazine, or TMP, is a popular food flavor additive which also has a potential in dietotherapy functions, such as in cardiovascular and cerebrovascular health. However, current production methods have low yields and efficiency. The China University of Petroleum researchers led by Zijun Xiao have found a temperature-controlled preparation method for TMP with improved yield and efficiency. 

First, glucose is biosynthesized by Bacillus subtilis CICC 10211 for 29 hours in a fermentor at 37C, pH 7.0. The speed of the stirring during biosynthesis is at 500 rpm with 1.0 vvm of airflow. The biosynthesis will yield action, the precursor of TMP. After biosynthesis, acetoin is transferred to another reactor and mixed with diammonium phosphate at 95C for 2.5 hours. A temporary by-product was formed but decomposed quickly under higher temperature. The method also received consistent results when tested using other strains of bacteria. Crystallized TMP with high purity (99.9%) was harvested by filtration.

The method can be expanded for other acetoin-producing strains and it gives high product yield and production efficiency for TMP production from renewable materials.

Bio-refineries produce large volumes of waste streams with high organic content, such as molasses, which have potential for further processing. Anaerobic digestion can be a key technology for treatment of these sidestreams. However, the high concentration of salts in molasses can cause inhibition of methanogenesis.

In this published  research conducted by the team of Jo De Vrieze from Ghent University, Belgium, concentrated and diluted molasses were subjected to biomethanation in two types of submerged anaerobic bioreactors, one with biogas recirculation and one with a vibrating membrane. Both reactors were compared in terms of methane production and membrane fouling.

Analysis revealed that, using the bioreactor with biogas recirculation can avoid membrane fouling. The use of diluted molasses as raw material led to a more stable methane production while concentrated molasses caused a decrease in methane production. Results also revealed the clear advantage of using Methanosaetaceae over Methanosarcinaceae in methane production.