The mutant lacking ORF469 fragment in Synechocystis sp. PCC 6803 (cyanobacterium) was created by means of DNA recombination. In its genome, ORF469, the key DNA fragment controlling the light-independent pathway of chl...The mutant lacking ORF469 fragment in Synechocystis sp. PCC 6803 (cyanobacterium) was created by means of DNA recombination. In its genome, ORF469, the key DNA fragment controlling the light-independent pathway of chlorophyll biosynthesis was deleted and replaced by erythromycin resistance cassette. The operation resulted in the fact that the content of chlorophyll in mutant cells was fully controlled by illumination and two kinds of cells were harvested, one is high chlorophyll with concentration of 9.427 μg · mg-1 and the other is low chlorophyll with concentration of 0.695 μg ·mg-1. They were subjected to thermal simulation respectively at 300℃ for 100 h. The alkanes biomarkers from pyrolysates were analyzed by GC-MS and main difference between high and low chlorophyll cells was found at their contents of isoprenoid hydrocarbons. Pr/nC17 and Ph/nC18 from pyrolysate of low chlorophyll cells were 0.192 and 0.216 respectively, which were about 1/3 and 1/7 of that from high chlorophyll cells. The展开更多
With the growing demand for air transportation combined with global concerns about environmental issues and the instability and lack of renewability of the oil market,microbial production of high energy density fuels ...With the growing demand for air transportation combined with global concerns about environmental issues and the instability and lack of renewability of the oil market,microbial production of high energy density fuels for jets(bio-jet fuels)has received more attention in recent years.Bio-jet fuels can be derived from both isoprenoids and fatty acids,and,additionally,aromatic hydrocarbons derived from expanded shikimate pathways are also candidates for jet fuels.Compared to fatty acid derivatives,most of isoprenoids and aromatic hydrocarbons used for jet fuels have higher density energies.However,they are also highly toxic to host microbes.The cytotoxicity induced during the synthesis of isoprenoid or shikimate pathway-derived biofuels remains one of the major obstacles for industrial production even though synthetic and systems biology approaches have reconstructed and optimized metabolic pathways for production of these bio-jet fuels.Here,we review recent developments in the production of known and potential jet fuels by microorganisms,with a focus on alleviating cytotoxicity caused by the final products,intermediates,and metabolic pathways.展开更多
文摘The mutant lacking ORF469 fragment in Synechocystis sp. PCC 6803 (cyanobacterium) was created by means of DNA recombination. In its genome, ORF469, the key DNA fragment controlling the light-independent pathway of chlorophyll biosynthesis was deleted and replaced by erythromycin resistance cassette. The operation resulted in the fact that the content of chlorophyll in mutant cells was fully controlled by illumination and two kinds of cells were harvested, one is high chlorophyll with concentration of 9.427 μg · mg-1 and the other is low chlorophyll with concentration of 0.695 μg ·mg-1. They were subjected to thermal simulation respectively at 300℃ for 100 h. The alkanes biomarkers from pyrolysates were analyzed by GC-MS and main difference between high and low chlorophyll cells was found at their contents of isoprenoid hydrocarbons. Pr/nC17 and Ph/nC18 from pyrolysate of low chlorophyll cells were 0.192 and 0.216 respectively, which were about 1/3 and 1/7 of that from high chlorophyll cells. The
基金supported by National Natural Science Foundation of China(No.32170084)Shandong Provincial Science Fund for Distin-guished Young Scholars(No.ZR2020JQ11),Young Taishan Scholars(No.TSQN201909159)+1 种基金Research and innovation fund of Shandong En-ergy Institute(No.SEI I202135 and No.SEI I202113)Natural Science Foundation of Shandong Province(No.ZR2019BC060)and Youth Inno-vation Promotion Association,CAS(Y2021063).
文摘With the growing demand for air transportation combined with global concerns about environmental issues and the instability and lack of renewability of the oil market,microbial production of high energy density fuels for jets(bio-jet fuels)has received more attention in recent years.Bio-jet fuels can be derived from both isoprenoids and fatty acids,and,additionally,aromatic hydrocarbons derived from expanded shikimate pathways are also candidates for jet fuels.Compared to fatty acid derivatives,most of isoprenoids and aromatic hydrocarbons used for jet fuels have higher density energies.However,they are also highly toxic to host microbes.The cytotoxicity induced during the synthesis of isoprenoid or shikimate pathway-derived biofuels remains one of the major obstacles for industrial production even though synthetic and systems biology approaches have reconstructed and optimized metabolic pathways for production of these bio-jet fuels.Here,we review recent developments in the production of known and potential jet fuels by microorganisms,with a focus on alleviating cytotoxicity caused by the final products,intermediates,and metabolic pathways.
