I am operating a continuous cultivation at fixed carbon and nitrogen concentrations, and under carbon-limitation regime and varying dilution rates from 0.1 to 0.01/hr. Under these conditions all the other kinetic parameters are at steady state, even when I change the flow rate (or dilution rate). But I am observing a shift up and shift down in product profile and after 2-3 residence time, no product is observed in the HPLC. And this is happening at every Dilution. I am perplexed seeing such product profile. My current hypothesis is that the product may be an intermediate product rather than the end product, or there is some kind of degradation is going on? I am not sure. So, If anyone has any idea regarding the product formation (secondary metabolite, polyketide pathway), in chemostat, please let me know?