THE NEGATIVE EXPRESSION OF PEPC GENE IN CYANOBACTERIA TO IMPROVE THE PRODUCTIVITY OF BIODIESEL MATERIAL

摘要

The contents of lipids based on biomass are higher than in higher plants, and the accumulation of biomass is much more rapid than in higher plants as well. For improving the productivity of biodiesel material this work tried to increase the content of lipids in cyanobacteria by negative expression of PEPC with antisense technique. The conservative sequence of PEPC from Anabaena (Nostoc) sp PCC 7120 was selected as the target gene fragment (pepcA), which was inserted into the shuttle expression vector pRL-489 in forward or reversely orientation to form pRL-Sen pepcA and pRL-Anti pepcA. The recombinant expression vectors were transferred to Anabaena sp. PCC 7120. Comparing with wild type cells the PEPC enzyme activity of transgenic Anabaena with pRL-Anti pepcA decreased 87.1%, the synthesis of lipids increased 54.7%; While the PEPC enzyme activity of transgenic Anabaena with pRL-Sen pepcA increased 81.1%, and the lipids content decreased 58.4%; These data has not been seen before and may open a new approach to make biodiesel from microalgae.