In situ modifications to bacterial cellulose with the water insoluble polymer poly-3-hydroxybutyrate

► Properties of bacterial cellulose (BC) can be altered using non-growth based additives. ► BC properties were modified with the addition of poly-3-hydroxybutyrate (PHB). ► PHB was incorporated into the BC fibrils during production. ► PHB modified BC offers an improved interface with BC in a PHB composite matrix.