In our life, various types of polymers are available, utilized in several sectors. Synthetic and natural polymers are now found in different natures of packaging tasks of our valuable products. But the synthetic utility of polymers in packaging material is found to be a big challenge for their degradation issue in the environment. In the last few decades, various kinds of packaging have been developed that use fossil origin products and also natural origin products like starch, chitin, or other biomolecules. Natural origin polymers are always found to be biodegradable and also eco-friendly products. Polylactic acids, chitin, and starch-based packaging material nowadays showed more interest in packaging tasks. In this context, the report for microbial-derived polyhydroxyalkanoates (PHA) polymers has found more application due to their several structural and functional properties. Much research is done on the huge production of PHA polymer with the utilization of an effective microbial system and cheap carbon sources like food waste biomass and also agricultural residue. This chapter explores the microbial-derived PHA polymer synthesis, like P-3-HB-co-4-HB (~poly-3-hydroxybutyrate-co-4-hydroxybutyrate) and PHB (~poly-3-hydroxybutyrate), with exploitation of several carbon and nitrogen sources. Later, PHA applications can be focused on special emphasis on bone and wound healing applications.