<P><B>Abstract</B></P><P>A techno-economic analysis of submerged (SmF) and solid state fermentation (SSF) processes for <I>Aspergillus carbonarius</I> polygalacturonase production was performed to make an appropriate process selection. The downstream processing involved integrated membrane process (IMP) and alginate affinity precipitation (AAP). For a production scale of 30kL purified polygalacturonase concentrate per year, the total upstream cost of SmF was 14% lower than the SSF process. Downstream processing cost by IMP was 47% lower than AAP. The SmF-IMP process required a total capital investment that was 15–24% lower than the SmF-AAP and SSF-AAP processes. The corresponding unitary product cost was also lower by 24–36% in SmF-IMP process. Thus the SmF-IMP process proved to be very attractive from an economic point of view.</P>