Abstract: The present invention provides submerged fermentation processes of producing one or more polypeptide of interest, the process comprising: a) fermenting one or more microorganism that produces the one more polypeptide of interest in a fermentation broth, and b) adding at least one enzyme to the fermentation broth: OR co-expressing the at least one enzyme in the one or more microorganism and secreting the at least one enzyme into the fermentation broth in an amount sufficient to reduce the viscosity of the fermentation broth, compared to when the at least one enzyme is not added or co-expressed; and, optionally, c) recovering the one or more polypeptide of interest.