Fig. 7

Controlled batch cultivations of citB overexpressing mutants and parental strain. a HPLC analysis of controlled batch cultivations of AB1.13 CitB mutants #99, 113# and AB1.13 CAD + MFS + MTT #49. Both citB transformants show complete conversion of CA into IA as there is little to no production of CA by these strains. IA production halts after 120 h for CitB #99 and after 192 h for CitB #113. The highest titer reached by the parental AB1.13 #49 strain is 12.96 g/L IA and 8.91 g/L CA whereas CitB #99 and #113 reach a highest titer of 26.2 and 23.42 g/L IA and 0.3 and 0.35 g/L CA. b Biomass development during controlled batch cultivations of AB1.13 CitB#99, #113 and AB1.13 CAD + MFS + MTT #49. Glucose is consumed at identical rate by all three strains but biomass formation is much lower for the citB overexpressing strains #99 and #113. CitB #99 and #113 reach a final biomass concentration of 12.0 and 12.38 g/kg, whereas the parental AB1.13 #49 strain reaches a final biomass concentration of 21.96 g/kg. Also it becomes evident that fungal growth is severely hampered by relatively high amounts of IA in the fermentation broth of CitB#99 and #113