Earticle

초록

영어

Glycerol is an abundant, inexpensive, and highly reduced molecule generated as inevitable by-product of biofuels production. Its use as carbon source in fermentation processes offers the opportunity to produce reduced chemicals at yields higher than those obtained with the use of common sugars. Fully realizing this potential, however, would require the metabolism of glycerol in the absence of electron acceptors. Unfortunately, fermentative utilization of glycerol is restricted to a small group of microorganisms, most of them not amenable to industrial applications. The synthesis of 1,3-propanediol (1,3-PDO) by these organisms has long been considered the metabolic property that determines their ability to ferment glycerol. We have recently discovered that E. coli can ferment glycerol in a 1,3-PDO-independent manner. We identified 1,2-propanediol (1,2-PDO) as a fermentation product and established the pathway that mediates its synthesis as well as its role in the metabolism of glycerol. Based on our findings, we proposed a new model for the fermentative utilization of glycerol in which: (1) the production of 1,2-PDO provides a means to consume reducing equivalents generated in the synthesis of cell mass, thus facilitating redox balance, and (2) the conversion of glycerol to ethanol, through a redox-balanced pathway, fulfills energy requirements by generating ATP via substrate-level
phosphorylation. Other auxiliary or enabling pathways facilitating this metabolic process
were identified along with the culture conditions triggering them, and therefore facilitating glycerol fermentation. We have also shown that this model for the 1,2-PDO-dependent fermentation of glycerol is valid for other microorganisms. The knowledge base created by the aforementioned studies has been instrumental in the implementation of metabolic engineering strategies to convert glycerol to a variety of fuels and reduced chemicals, including ethanol, hydrogen, formate, succinate, and 1,2-PDO. We will present at the meeting our latest results in the understanding of this new metabolic competency and the metabolic engineering of these microorganisms to produce different chemicals from glycerol.

저자

• Ramon Gonzalez [ Department of Bioengineering, RiceUniversity ]

참고문헌

발행기관

간행물

표지보기 관심저널 등록

• 간행물명

  한국생물공학회 학술대회

• 간기

  반년간

• 수록기간

  1985~2013

• 십진분류

  KDC 476 DDC 576