Characterization of sulfur-compound metabolism underlying wax-ester fermentation in Euglena

January 30, 2019

Achievement contributing to biofuel production efficiency

A team of researchers from Euglena Corporation, RIKEN and the University of Tsukuba have clarified the metabolic changes of sulfur compounds in a microalga, Euglena gracilis ('Midorimushi' in Japnese) underlying its wax-ester fermentation.

E. gracilis has been industrially used functional foods and cosmetics, and further studied to increase its oil production level. E. gracilis can produce wax-ester through decomposition of paramylon a storage polysaccharide, paramylon. This process is known as wax-ester fermentation, and empirically known to accompany the generation of a nasty odor.

The research team analyzed oil samples from E. gracilis using the Sulfur Index,* that enables to comprehensively analyze sulfur compounds, and found that the main odor component is hydrogen sulfide. They also found that this hydrogen sulfide is generated through degradation of proteins and glutathione in E. gracilis cells.

These findings provide us clues to develop technology to improve oil productivity and suppress the generation of odors in Euglena, which will contribute to accurate research for development of highly-efficient bio-fuel from microalga biomass.

* Sulfur Index is a service for analyzing sulfur compounds in samples using LC-MS/MS analysis. (in Japanese)

Original article
Scientific Reports doi:10.1038/s41598-018-36600-z
K. Yamada, T. Nitta, K. Atsuji, M. Shiroyama, K. Inoue, C. Higuchi, N. Nitta, S. Oshiro, K. Mochida, O. Iwata, I. Ohtsu, K. Suzuki,
"Characterization of sulfur-compound metabolism underlying wax-ester fermentation in Euglena gracilis".
Keiichi Mochida
Team Leader
Bioproductivity Informatics Research Team