Directed evolution of promising engineered strains to improve
their production capacity has received widespread attention in
recent years. This study aims to develop a robust C.
tyrobutyricum chassis which has an alternative non-oxidative
glycolysis (NOG) pathway to EMP pathway and can withstand
possible growth side effects of EMP modification during genomic
directed evolution for enhanced or expanded synthesis capacity
of bioproducts. We integrated a non-oxidative glycolysis (NOG)
pathway to EMP pathway in C. tyrobutyricum by introducing F/Xpk
gene. Plasmids using two F/Xpk genes and three different native
promoters, Pthl, Ptkt and Pfba, were constructed and transferred
into C. tyrobutyricum L319. By analyzing the growth and yields
of butyric acid and acetic acid of the strain, we found that
F/Xpk gene derived from C. acetobutylicum and Ptkt promoter was
the best combination for constructing NOG pathway in C.
tyrobutyricum, and xylose was the best carbon source for the
strain.