Polyesters are a family of both synthetic and natural polymers extensively used in a wide variety of applications from commodity materials to advanced engineering parts of space crafts. Polyester microparticles are produced intentionally for specific applications in agriculture, cosmetics, hygiene products, and medicine businesses. These particles could also be generated from mechanical or microbial degradation of larger parts and find their way inside the marine food chain, endangering the ecosystem as well as national and international food safety. To address such issues, we targeted bioproduction of polyhydroxy alkanoates (PHA) as they are non-toxic and fully biodegradable. Microbial production of such materials is limited due to the high cost of production, mostly from the carbon source. In this regard, we investigated the possibility of using manure as a sustainable feed stock addressing the environmental and economic concerns associated with manure management. Standard biodegradation assessment tests, generally known as soil burial methods, are extremely time-taking and their results are hard to reproduce. Thus, we devised and fabricated a microfluidic platform to immobilize polymeric microparticles and analyze their enzymatic degradation, in a close-to-static microflow condition, mimicking natural microbial degradation. We further developed a mathematical model to find the kinetic parameters of this class of degradation assuming shrinking particle- shrinking core model of transport phenomena. Polyhydroxy butyrate (PHB), the simplest form of PHA, is generally accepted as a hard-to-process thermoplastic due to its high degree of crystallinity, limiting its wide-spread application. We sought to take advantage of and even enhance this property as it can affect the biodegradation rate, making it a great platform for a controlled release system of micronutrients to plants and crops. Optimizing the genetic modification, genotype used, and culture conditions, we were able to bio-produce high-molecular weight PHB with 65% crystallinity. Loading this PHB with 30% of iron nanoparticles (micronutrient) resulted in a nanocomposite with 30% crystallinity which later was found to be an effective nano fertilizer for delivery of cargo to the soil within 10 weeks of addition to the soil. Pot experiments demonstrated that plants growing on soil amended with this nano fertilizer grew faster than control groups.