Success increasing production of bioplastic raw materials by hydrogen synthesis gene modification

July 20, 2016

Researchers of Meiji University, RIKEN CSRS, Kobe University and University of Porto have succeeded in increasing succinic acid and lactic acid production in cyanobacteria by modifying enzymes that synthesize hydrogen in a JST-ALCA program.

Succinic acid and lactic acid serve as a raw material for bioplastics. Succinic acid is currently synthesized from petroleum, but in recent years the production of bio-based succinic acid has been increasing. Organic acids from biological sources are produced by microbial fermentation by adding external sugars, although the sugars take much cost for microbial fermentation.

The research group focused on cyanobacteria, which directly fix carbon dioxide through photosynthesis and can also produce both organic acids and hydrogen through fermentation in dark, anaerobic conditions. The group found that genetically manipulating hydrogenases to reduce hydrogen synthesis increased production of succinic acid by five-fold and lactic acid by ten-fold.

This research has demonstrated a novel way to directly convert carbon dioxide to raw material for bioplastics. The development of photosynthesis-based manufacturing should contribute to solving future environmental and energy issues.


Original article
Algal Research doi: b10.1016/j.algal.2016.06.026b
H. Iijima, T. Shirai, Y. Nakaya, M. Okamoto, F. Pinto, P. Tamagnini, T. Hasunuma, A. Kondo, M. Yokota Hirai, T. Osanai,
"Metabolomics-based analysis revealing the alteration of primary carbon metabolism by the genetic manipulation of a hydrogenase HoxH in Synechocystis sp. PCC 6803".

Takashi Osanai; Visiting Scientist
Masami Hirai; Team Leader
Metabolic Systems Research Team