초록
<P>Fermentations employing anaerobes always suffer from the restriction of stringent anaerobic conditions during the production of bulk and fine chemicals. This work aims to improve the oxidative stress tolerance of <I>C. tyrobutyricum</I> CCTCC W428, an ideal butyric-acid-producing anaerobe, via the introduction of trehalose biosynthesis capability. Compared with the wild type, the engineered strain showed a wider substrate spectrum, an improved metabolic profile, and a significantly increased specific growth rate upon aeration and acid challenge. Molecular simulation experiments indicated that CoA transferase maintained its native folded state when protected by the trehalose system. Furthermore, qRT-PCR was combined assays for acid-related enzyme activities under various conditions to verify the effects of trehalose. These results demonstrate that introducing a trehalose biosynthetic pathway, which is redundant for the metabolism of <I>C. tyrobutyricum</I>, can increase the robustness of the host to achieve a better oxidative resistance.</P><P><B>Graphic Abstract</B><BR><IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jafcau/2017/jafcau.2017.65.issue-40/acs.jafc.7b03172/production/images/medium/jf-2017-03172c_0009.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/jf7b03172'>ACS Electronic Supporting Info</A></P>