Fatty acid production in genetically modified cyanobacteria

作者：Xinyao Liu, Jie Sheng, Roy Curtiss · 发表于：Proceedings of the National Academy of Sciences · 年份：2011 · DOI：10.1073/pnas.1103014108 · 被引用次数：535 · 研究领域：Algal biology and biofuel production、Microbial Metabolic Engineering and Bioproduction、Photosynthetic Processes and Mechanisms

To avoid costly biomass recovery in photosynthetic microbial biofuel production, we genetically modified cyanobacteria to produce and secrete fatty acids. Starting with introducing an acyl-acyl carrier protein thioesterase gene, we made six successive generations of genetic modifications of cyanobacterium Synechocystis sp. PCC6803 wild type (SD100). The fatty acid secretion yield was increased to 197 ± 14 mg/L of culture in one improved strain at a cell density of 1.0 × 10(9) cells/mL by adding codon-optimized thioesterase genes and weakening polar cell wall layers. Although these strains exhibited damaged cell membranes at low cell densities, they grew more rapidly at high cell densities in late exponential and stationary phase and exhibited less cell damage than cells in wild-type cultures. Our results suggest that fatty acid secreting cyanobacteria are a promising technology for renewable biofuel production.