Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) produced by mixed bacterial cultures derived from a cheese whey (CW) industrial by-product (unpurified PHBV; u-PHBV) was incorporated into commercial PHBV without previous purification or isolation processes. The presence of certain impurities was evident as investigated by scanning electron microscopy. The crystallinity of the polymer fraction was decreased b...