Efficient Polyhydroxyalkanoate Recovery from Recombinant Cupriavidus necator by Using Low Concentration of NaOH

摘要

An efficient method for recovering polyhydroxyalkanoate (PHA) from bacterial cell was developed by using a low concentration of sodium hydroxide (NaOH). In this study, the effectiveness of low-concentration NaOH on PHA recovery from recombinant Cupriavidus necator was investigated by testing several NaOH concentrations, in relation to digestion time and reaction temperature. Gas chromatography (GC) analysis showed that PHA with more than 96% purity and recovery yield can be achieved after the recovery process which involved treatment of lyophilized cells with 0.05 M NaOH at 4°C for 3 h. GC analysis was supported by transmission electron microscope images and associated with considerable release of protein after NaOH addition. The recovery process developed herein was found effective in recovering PHA even from cells with low PHA content, with only 13% reduction in molecular weight (Mw). Ultimately, the present method could be an alternative to the PHA recovery by organic solvents, with added values such as being simple, nontoxic and environmental friendly.