Worldwide attention is currently focused on bioethanol production from viewpoints of global warming prevention and energy security enforcement. However, feedstock for current bioethanol production processes comprises food crops, which will be in limited supplies in the near future. Therefore, there is a pressing need to use abundant lignocellulosic biomass, some obtained from inedible parts of food crops, is of as demand for bioethanol proliferates.

Corynebacterium glutamicum has widely been used in industrial microbial production of amino acid and nucleic acid. We constructed ethanologenic C. glutamicum strains to demonstrate ethanol production under growth-arrested conditions, with cells of the strain packed in a reactor at high density. Growth-arrested conditions were implemented by oxygen deprivation, which enabled the cells to produce ethanol at high volumetric productivity. Now, we are trying to improve the process for ethanol production from mixed sugars containing hexose and pentose sugars derived from lignocellulosic biomass.

This study was partially supported by a grant from New Energy and Industrial Technology Development Organization (NEDO).