Previous work has demonstrated the feasibility of in vivo biodiesel synthesis in Escherichia coli, however, ethyl ester formation was dependent on an external fatty acid feedstock. In contrast to E. coli, actinomycetes may be ideal organisms for direct biodiesel synthesis because of their capacity to synthesize high levels of triacylglcerides (TAGs). In this study, we investigated the physiology and associated TAG accumulation along with the in vivo ability to catalyze ester formation from exogenous short chain alcohol sources in Gordonia sp. KTR9, a strain that possesses a large number of genes dedicated to fatty acid and lipid biosynthesis. Total lipid fatty acids content increased by 75 % and TAG content increased by 50 % under nitrogen starvation conditions in strain KTR9. Strain KTR9 tolerated the exogenous addition of up to 4 % methanol, 4 % ethanol and 2 % propanol in the media. Increasing alcohol concentrations resulted in a decrease in the degree of saturation of recovered fatty acid alcohol esters and a slight increase in the fatty acid chain length. A linear dose dependency in fatty alcohol ester synthesis was observed in the presence of 0.5-2 % methanol and ethanol compared to control KTR9 strains grown in the absence of alcohols. An inspection of the KTR9 genome revealed the presence of several putative wax ester synthase/acyl-coenzyme A : diacylglycerol acyltransferase (WS/DGAT) enzymes, encoded by atf gene homologs, that may catalyze the in vivo synthesis of fatty acid esters from short chain alcohols. Collectively, these results indicate that Gordonia sp. KTR9 may be a suitable actinomycete host strain for in vivo biodiesel synthesis.

译文

以前的工作已经证明了在大肠杆菌中体内合成生物柴油的可行性,但是,乙酯的形成取决于外部脂肪酸原料。与大肠杆菌相反,放线菌可能是直接合成生物柴油的理想生物,因为它们具有合成高水平的三酰基玻璃酸酯 (标签) 的能力。在这项研究中,我们研究了Gordonia sp. KTR9的生理和相关TAG积累以及体内催化外源短链醇源形成酯的能力,该菌株具有大量专用于脂肪酸和脂质生物合成的基因。在氮饥饿条件下,菌株ktr9的总脂质脂肪酸含量增加75%,TAG含量增加50%。菌株KTR9耐受培养基中最多4% 甲醇、4% 乙醇和2% 丙醇的外源添加。酒精浓度的增加导致回收的脂肪酸醇酯的饱和度降低,脂肪酸链长度略有增加。与在没有醇的情况下生长的对照KTR9菌株相比,在0.5 2% 的甲醇和乙醇存在下观察到脂肪醇酯合成中的线性剂量依赖性。对KTR9基因组的检查显示,存在几种推定的蜡酯合酶/酰基辅酶a  :  二酰基甘油酰基转移酶 (WS/DGAT) 酶,这些酶由atf基因同源物编码,可以催化体内合成脂肪酸短链醇的酯。总的来说,这些结果表明Gordonia sp。KTR9可能是用于体内生物柴油合成的合适的放线菌宿主菌株。

+1
+2
100研值 100研值 ¥99课程
检索文献一次
下载文献一次

去下载>

成功解锁2个技能,为你点赞

《SCI写作十大必备语法》
解决你的SCI语法难题!

技能熟练度+1

视频课《玩转文献检索》
让你成为检索达人!

恭喜完成新手挑战

手机微信扫一扫,添加好友领取

免费领《Endnote文献管理工具+教程》

微信扫码, 免费领取

手机登录

获取验证码
登录