Itaconic acid production of A. niger transformants. A ): Itaconic acid HPLC analysis of micro titer plate screening of A. niger CAD transformants. B): Itaconic acid screening results in micro-titer plate for the selected GPD and HBD transformants. The parental strain CAD 10.1 was used as a control. The transformants with the highest production and lowest production surrounded by an oval circle were selected further for Southern blot analysis.