Tailoring Triacylglycerol Biosynthetic Pathway in Plants for Biofuel Production

2019 ◽  
pp. 41-60 ◽  
Author(s):  
Kshitija Sinha ◽  
Ranjeet Kaur ◽  
Rupam Kumar Bhunia
2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Yanfei Zhang ◽  
Stephan Lane ◽  
Jhong-Min Chen ◽  
Sarah K. Hammer ◽  
Jake Luttinger ◽  
...  

Abstract Background Branched-chain higher alcohols (BCHAs), including isobutanol and 2-methyl-1-butanol, are promising advanced biofuels, superior to ethanol due to their higher energy density and better compatibility with existing gasoline infrastructure. Compartmentalizing the isobutanol biosynthetic pathway in yeast mitochondria is an effective way to produce BCHAs from glucose. However, to improve the sustainability of biofuel production, there is great interest in developing strains and processes to utilize lignocellulosic biomass, including its hemicellulose component, which is mostly composed of the pentose xylose. Results In this work, we rewired the xylose isomerase assimilation and mitochondrial isobutanol production pathways in the budding yeast Saccharomyces cerevisiae. We then increased the flux through these pathways by making gene deletions of BAT1, ALD6, and PHO13, to develop a strain (YZy197) that produces as much as 4 g/L of BCHAs (3.10 ± 0.18 g isobutanol/L and 0.91 ± 0.02 g 2-methyl-1-butanol/L) from xylose. This represents approximately a 28-fold improvement on the highest isobutanol titers obtained from xylose previously reported in yeast and the first report of 2-methyl-1-butanol produced from xylose. The yield of total BCHAs is 57.2 ± 5.2 mg/g xylose, corresponding to ~ 14% of the maximum theoretical yield. Respirometry experiments show that xylose increases mitochondrial activity by as much as 7.3-fold compared to glucose. Conclusions The enhanced levels of mitochondrial BCHA production achieved, even without disrupting ethanol byproduct formation, arise mostly from xylose activation of mitochondrial activity and are correlated with slow rates of sugar consumption.


2002 ◽  
Vol 69 ◽  
pp. 47-57 ◽  
Author(s):  
Catherine L. R. Merry ◽  
John T. Gallagher

Heparan sulphate (HS) is an essential co-receptor for a number of growth factors, morphogens and adhesion proteins. The biosynthetic modifications involved in the generation of a mature HS chain may determine the strength and outcome of HS–ligand interactions. These modifications are catalysed by a complex family of enzymes, some of which occur as multiple gene products. Various mutant mice have now been generated, which lack the function of isolated components of the HS biosynthetic pathway. In this discussion, we outline the key findings of these studies, and use them to put into context our own work concerning the structure of the HS generated by the Hs2st-/- mice.


2013 ◽  
Author(s):  
Pancheewa Benjamasutin ◽  
◽  
Ponthong Rijana ◽  
Phongchayont Srisuwan ◽  
Aussadavut Dumrongsiri

2020 ◽  
pp. 22-30
Author(s):  
SERGEY N. DEVYANIN ◽  
◽  
VLADIMIR A. MARKOV ◽  
ALEKSANDR G. LEVSHIN ◽  
TAMARA P. KOBOZEVA ◽  
...  

The paper presents the results of long-term research on the oil productivity and chemical composition of soybean oil of the Northern ecotype varieties in the Central Non-Black Earth Region. The authors consider its possible use for biodiesel production. Experiments on growing soybeans were carried out on the experimental fi eld of Russian State Agrarian University –Moscow Timiryazev Agricultural Academy (2008-2019) on recognized ultra-early ripening varieties of the Northern ecotype Mageva, Svetlaya, Okskaya (ripeness group 000). Tests were set and the research results were analyzed using standard approved methods. It has been shown that in conditions of high latitudes (57°N), limited thermal resources of the Non-Chernozem zone of Russia (the sum of active temperatures of the growing season not exceeding 2000°С), the yield and productivity of soybeans depend on the variety and moisture supply. Over the years, the average yield of soybeans amounted to 1.94 … 2.62 t/ha, oil productivity – 388 … 544 kg/ha, oil content – 19…20%, the content of oleic and linoleic fatty acids in oil – 60%, and their output from seeds harvested – 300 kg/ha. It has been established that as soybean oil and diesel fuel have similar properties,they can be mixed by conventional methods in any proportions and form stable blends that can be stored for a long time. Experimental studies on the use of soybean oil for biodiesel production were carried out on a D-245 diesel engine (4 ChN11/12.5). The concentrations of toxic components (CO, CHx, and NOx) in the diesel exhaust gases were determined using the SAE-7532 gas analyzer. The smoke content of the exhaust gases was measured with an MK-3 Hartridge opacimeter. It has been experimentally established that the transfer of a diesel engine from diesel fuel to a blend of 80% diesel fuel and 20% lubrication oil leads to a change in the integral emissions per test cycle: nitrogen oxides in 0.81 times, carbon monoxide in 0.89 times and unburned hydrocarbons in 0.91 times, i.e. when biodiesel as used as a motor fuel in a serial diesel engine, emissions of all gaseous toxic components are reduced. The study has confi rmed the expediency of using soybeans of the Northern ecotype for biofuel production.


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