Division of Biotechnology and Life Science, Institute of Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo, Japan.
Appl Microbiol Biotechnol. 2015 Feb;99(3):1521-9. doi: 10.1007/s00253-014-6286-2. Epub 2014 Dec 21.
The production of alkanes in a marine cyanobacterium possessing the α-olefin biosynthesis pathway was achieved by introducing an exogenous alkane biosynthesis pathway. Cyanobacterial hydrocarbons are synthesized via two separate pathways: the acyl-acyl carrier protein (ACP) reductase/aldehyde-deformylating oxygenase (AAR/ADO) pathway for the alkane biosynthesis and the α-olefin synthase (OLS) pathway for the α-olefin biosynthesis. Coexistence of these pathways has not yet been reported. In this study, the marine cyanobacterium Synechococcus sp. NKBG15041c was shown to produce α-olefins similar to those of Synechococcus sp. PCC7002 via the α-olefin biosynthesis pathway. The production of heptadecane in Synechococcus sp. NKBG15041c was achieved by expressing the AAR/ADO pathway genes from Synechococcus elongatus PCC 7942. The production yields of heptadecane in Synechococcus sp. NKBG15041c varied with the expression level of the aar and ado genes. The maximal yield of heptadecane was 4.2 ± 1.2 μg/g of dried cell weight in the transformant carrying a homologous promoter. Our results also suggested that the effective activation of ADO may be more important for the enhancement of alkane production by cyanobacteria.
通过引入外源烷烃生物合成途径，在一种具有α-烯烃生物合成途径的海洋蓝细菌中生产烷烃成为可能。蓝细菌烃通过两条独立的途径合成：用于烷烃生物合成的酰基-酰基载体蛋白（ACP）还原酶/醛-去甲氧酶（AAR/ADO）途径和用于α-烯烃生物合成的α-烯烃合酶（OLS）途径。这些途径的共存尚未见报道。在这项研究中，海洋蓝细菌 Synechococcus sp. NKBG15041c 被证明可以通过α-烯烃生物合成途径产生类似于 Synechococcus sp. PCC7002 的α-烯烃。通过表达 Synechococcus elongatus PCC 7942 的 AAR/ADO 途径基因，Synechococcus sp. NKBG15041c 能够生产十七烷。Synechococcus sp. NKBG15041c 中十七烷的产量随 aar 和 ado 基因的表达水平而变化。在携带同源启动子的转化体中，十七烷的最大产量为 4.2±1.2 μg/g 干重。我们的结果还表明，ADO 的有效激活可能对蓝细菌烷烃产量的提高更为重要。
