1.Production of FAME biodiesel in E. coli by direct methylation with an insect enzyme.
Sherkhanov S1, Korman TP1, Clarke SG1, Bowie JU1. Sci Rep. 2016 Apr 7;6:24239. doi: 10.1038/srep24239.
Most biodiesel currently in use consists of fatty acid methyl esters (FAMEs) produced by transesterification of plant oils with methanol. To reduce competition with food supplies, it would be desirable to directly produce biodiesel in microorganisms. To date, the most effective pathway for the production of biodiesel in bacteria yields fatty acid ethyl esters (FAEEs) at up to ~1.5 g/L. A much simpler route to biodiesel produces FAMEs by direct S-adenosyl-L-methionine (SAM) dependent methylation of free fatty acids, but FAME production by this route has been limited to only ~16 mg/L. Here we employ an alternative, broad spectrum methyltransferase, Drosophila melanogaster Juvenile Hormone Acid O-Methyltransferase (DmJHAMT). By introducing DmJHAMT in E. coli engineered to produce medium chain fatty acids and overproduce SAM, we obtain medium chain FAMEs at titers of 0.56 g/L, a 35-fold increase over titers previously achieved. Although considerable improvements will be needed for viable bacterial production of FAMEs and FAEEs for biofuels, it may be easier to optimize and transport the FAME production pathway to other microorganisms because it involves fewer enzymes.
2.Neuroprotective Properties of Compounds Extracted from Dianthus superbus L. against Glutamate-induced Cell Death in HT22 Cells.
Yun BR1, Yang HJ1, Weon JB1, Lee J1, Eom MR1, Ma CJ2. Pharmacogn Mag. 2016 Apr-Jun;12(46):109-13. doi: 10.4103/0973-1296.177905.
BACKGROUND: Dianthus superbus L. has been used in Chinese herbal medicine as a diuretic and anti-inflammatory agent.
3.Application of AlkBGT and AlkL from Pseudomonas putida GPo1 for selective alkyl ester ω-oxyfunctionalization in Escherichia coli.
van Nuland YM1, Eggink G2, Weusthuis RA3. Appl Environ Microbiol. 2016 Apr 15. pii: AEM.00822-16. [Epub ahead of print]
The enzyme system AlkBGT fromPseudomonas putidaGPo1 can efficiently ω-functionalize fatty acid methyl esters. Outer membrane protein AlkL boosts this ω-functionalization. In this study it is shown that whole-cells ofE. coliexpressing the AlkBGT system can also ω-oxidize ethyl nonanoate (NAEE). Co-expression of AlkBGT and AlkL resulted in 1.7-fold higher ω-oxidation activity on NAEE. With this strain, initial activity on NAEE was 70 U/gcdw, 67% of the initial activity on methyl nonanoate. In time-lapse conversions with 5 mM NAEE the main product was 9-hydroxy NAEE (3.6 mM), but also 9-oxo NAEE (0.1 mM) and 9-carboxy NAEE (0.6 mM) were formed. AlkBGT also ω-oxidized ethyl, propyl and butyl esters of fatty acids ranging from C6 to C10. Increasing the length of the alkyl chain improved the ω-oxidation activity of AlkBGT on esters of C6 and C7 fatty acids. From these esters, application of butyl hexanoate resulted in the highest ω-oxidation activity of 82 U/gcdw Co-expression of AlkL only had a positive effect on ω-functionalization of substrates with a total length of C11 or longer.
4.A New Neolignan from Coix lachryma-jobi var. mayuen.
Kim SY, Choi CW, Hong SS, Shin H, Oh JS. Nat Prod Commun. 2016 Feb;11(2):229-31.
A new neolignan, named coixide A (1), along with fifteen known compounds, (7R,8S)-3'-demethyl-dehydrodiconiferyl alcohol-3'-O-β-glucopyranoside (2), (7R,8)-3'-demethyl-9'-butoxy-dehydrodiconiferyl-3'-O-β-glucopyranoside (3),adenosine (4), 2-O-caffeoyl isocitricacid (5), pseudolaroside A (6), 2-hydroxy-7-methoxy-(2H)-1,4-benzoxazin-3(4H)-one (7), 2-O-β-glucopyranosyl-7-methoxy-2H-1,4-benzoxazin-3(4H)-one (8), 2-O-β-glucopyranosyl-4-hydroxy-7- methoxy-2H-1,4-benzoxazin-3(4H)-one (9), 2-O-β-D-glucopyranosyl-7-hydroxy-2H-1,4-benzoxazin-3(4H)-one (10), p-coumaric acid ethyl ester (11), caffeic acid ethyl ester (12), p-coumaric acid (13), cis-N-p-coumaroyltyramine (14) trans-N-p-coumaroyltyramine (15), and coixol (16) have been isolated from Coix lachryma-jobi var. mayuen. Their chemical structures were elucidated by chemical evidence on the basis of spectroscopic and MS data, and as well as by comparison with those reported.