Poly[(R)-3-hydroxybutyrate]: the Green Biodegradable Bioplastics of the Future!

Abstract

Copyright: © 2013 Dhaman Y, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. At present, most plastic materials that are widely used on daily basis are non-biodegradable products derived from fossil fuels. Due to the increase in population and industrialization, there is now increased awareness of the impact of these non-biodegradable plastics on the environment. A lot of efforts are now geared towards developing various biodegradable plastics. Biodegradable polymers can be broadly classified under polynucleotides, polyamides, polysaccharides, polyoxoesters, polythioesters, polyphosphates, polyisoprenoides and polyphenols [1]. Poly[(R)-3-hydroxybutyrate] (PHB), the most widely studied member of PHA (polyoxoesters) is very promising as a biodegradable plastic because of its material properties which are comparable to those of the polypropylene [2]. PHB is a natural polymer produced by many bacteria as carbon and energy storage materials. PHB can be synthesized from renewable low-cost feedstocks and its polymerizations are operated under mild process conditions with minimal environmental impact [3]. A good number of microbial strains are known to produce PHB under certain growth conditions. Among these groups of bacteria, R. eutropha and A. latus are the most widely studied [4,5], and very high PHB contents up to 76% (w/w) have been reported [6]. Furthermore, PHB can be degraded in both aerobic and anaerobic environments, without forming any toxic products [7]. PHB can be used as biomaterials (e.g., bone regeneration, dressing of wounds, sutures, etc.) [8]. In addition, it can be used as packaging materials [9]. Some studies have also shown that PHB can serve as micro-particulate carrier of drugs [10].