This work investigated the separation of polyhydroxybutyrate (PHB) containing Ralstonia eutropha cells from the culture broth using a novel ceramic based tubular membrane assembly. The culture broth was fed into outer surface of the membrane (shell side) and permeate was drawn from the tube side. Further, the number of ceramic membranes in the assembly was raised from 1 to 4 and its performance was assessed by measuring the broth flux, biomass and PHB recovery as a function of applied pressure (49 kPa - 196 kPa). The present ceramic membrane is found to be highly efficient (99.9 +/- 0.03%) in recovering the PHB from the culture broth. A maximum initial water flux of 444 L m(-2) h(-1) and a permeate broth flux of 52 L m(-2) h(-1) was observed at the maximum applied pressure (196 kPa) and with four number of ceramic membranes added to the membrane assembly. Both biomass and PHB recovery were observed to decrease with an increase in the applied pressure; on the contrary, a reduction in the applied pressure enhanced the biomass and PHB recovery, but at the cost of low broth flux. However, this relationship is overcome by increasing the number of membranes in the membrane assembly. (C) 2019 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.