NOVELTY - Preparing polyhydroxyalkanoate comprises: growing a culture of Acetobacter aceti in a nutrient rich medium; recovering a biomass by centrifuging the broth; treating the biomass with a freshly prepared solvent system; keeping the biomass solution mixture to obtain three layers comprising upper layer, middle layer and lower layer; separating and centrifuging the lower layer; separating the polyhydroxyalkanoates through precipitation; separating and centrifuging the precipitate mixture; and dissolving the precipitate mixture in a first solvent and precipitating with a second solvent.    USE - The method is useful for preparing polyhydroxyalkanoate for enhancing microbial electrocatalysis (all claimed).    ADVANTAGE - The reproducible method economically prepares the polyhydroxyalkanoate with high yield and improved biodegradability and biocompatibility.    DETAILED DESCRIPTION - Preparing polyhydroxyalkanoate comprises: (i) growing a culture of Acetobacter aceti in a nutrient rich medium to form a broth; (ii) recovering a biomass by centrifuging the broth and further drying the biomass; (iii) treating the biomass obtained from step (ii) with a freshly prepared solvent system to form a biomass solution mixture; (iv) keeping the biomass solution mixture obtained from step (iii) to obtain three layers comprising an upper layer, a middle layer and a lower layer, where the upper and the middle layers are discarded; (v) separating and centrifuging the lower layer obtained from step (iv); (vi) separating the polyhydroxyalkanoates through precipitation to get a precipitate mixture; (vii) separating and centrifuging the precipitate mixture obtained from step (vi); and (viii) dissolving the precipitate mixture in a first solvent and precipitating with a second solvent to obtain highly purified polyhydroxyalkanoate. An INDEPENDENT CLAIM is included for enhancing microbial electrocatalysis comprising functionalizing the polyhydroxyalkanoate on a surface of an electrode to form a polyhydroxyalkanoate functionalized electrode and then allowing to form a biofilm, and performing bio-electrocatalysis of a substrate by the biofilm using the polyhydroxyalkanoate functionalized electrode.