generate uniform drops of different volumes the flow rates of continuous and disperse phases were varied and the geometry of flow focusing nozzle to generate polydisperse drops the culture media were mixed with the continuous phase followed by manual shaking the size of the drops obtained ranged from 5 pl to 1 nl the drops generated were then collected in a gas tight vial and incubated with methane and oxygen injected in the headspace small volumes of the drops were sampled and destabilized for the characterization of cell growth and p3hb accumulation at various time points the rate of cell growth increased in emulsion based fermentation fig2 a shows bright field microscopy images of cells in 40 pl drops as a function of time at the initial concentration of cells used od 600 u02dc 0 1 corresponding to u02dc 9 28 u00d7 10 7 cells ml a 40 pl drop contained an average of 4 cells at t 0 h the number of cells in a drop increased significantly after 48 h no further increase was observed after 96 h the qualitative trend of cell growth from these microcopy images was consistent with optical density measurements fig2 b shows that cells replicated rapidly during the first 72 h to reach od 600 u02dc 0 7 corresponding to 6 50 u00d7 10 8 cells ml and stabilized afterwards in the control experiment where the cells were cultured with shaking at 150 rpm in the aqueous media without hfe 7500 or emulsions the cells also grew to a.