The present invention relates to improved methods for producing biosynthetic products in a cascade of bioreactors. In particular the present invention relates to methods and a cascade of bioreactor systems comprising at least two bioreactors and at least one concentration unit.

The invention provides a hydraulic fluid composition comprising a hydrocarbon component comprising more than 5 wt% of naphthenic oil and up to 95 wt% of renewable or recycled isoparaffinic oil based on the total weight of the composition. The hydraulic fluid composition is useful as an arctic hydraulic fluid composi...