4. Concluding remarks
This study describes the adaptation of the previously engineered
phenylalanine-overproducing chassis P. taiwanensis GRC3
Δ8ΔpykA -tap to enable microbial production of bio-benzoic
acid. The applied heterologous pathway converts phenylalanine viatrans -cinnamate to benzoate. Further, the catabolic versatility
of Pseudomonas was exploited to establish novel pathways for the
production of catechol and cis,cis -muconate. The catechol yields
were relatively low compared to previously achieved production
parameters for other aromatics, likely at least partially related to the
high toxicity of catechol. However, the yields achieved for benzoate andcis,cis -muconate are very promising and future efforts should be
made to increase the titers in a fed-batch fermentation. Benzoate has
significant relevance as food preservative and as a starting point for
the production of many other platform chemicals and secondary
metabolites, thus expanding the product spectrum of P.
taiwanensis as robust biotechnological workhorse.