Advantages And Disadvantages Of Bioplastic

Introduction

The non-biodegradability of petroleum-based plastics make a substantial challenge for the environmental ability to remove and recycling of them that offer drawback to health and environmental systems including soil infertility, the greenhouse gas and carcinogenic agents release under disposing process, landfill and incineration (approximately 60% of total products) (1-3). Because of the bio-material eco-friendly properties, commercially production of Polyhydroxyalkanoates (PHAs) as the most common representative of degradable plastics, known as bioplastic, gained the most attention, especially Polyhydroxybutyrate (PHB), and Polyhydroxybutyrate-co- hydroxyvalerate (PHBV) (4, 5).

A low cost protocol is one of the major demands

The composition of biomass as raw material provides a convincing explanation for the general use way which is renewable, available and biodegradable (21). Bioplastic produced of biomass have generally three main opportunistic include, the economy, the environment and medical application.

According to the figure.2, to production of biodegradable polymers called oxo-biodegradable plastics, an operating window is started by natural feed stocks such as agriculture and forestry residues, food industry and municipal solid waste by three conversion platforms, biochemical, chemical and thermochemical (22). proteins, lipids, polysaccharides and polyhydroxyalkanoate are obvious example for environmental friendly polymers (23). Moreover, there are currently other groups of the great important biotechnology degradable biopolymers like polylactic acid (PLA), poly vinyl alcohol (PVOH) (24).

Figure. 2 gives a brief summary of the applications of biomass-derived degradable polymers. Nowadays, there are tremendous interest in research and using of biopolymers in packaging, civil engineering, biomedical and automotive mystery

As for, bioplastic biodegradability and biocompatibility, Biotechnological application fully exploits of these properties and many type of bioplastics have been successfully biosynthesized using by new biotechnological strategies (28). Hence, several strategies have been developed to increase of bulk production that are more efficient and less expensive (29). These are considered as multilateral, for example: definition of the modified cultures for generation of wide range of biopolymer monomers using wide range of feedstocks, utilization of engineered micro-organisms in order to use different inexpensive carbon sources such as grape pomace, waste frying oil, fish solid waste, methane, molasses and glycerol (30-34). Figure.1: General scheme of three metabolic pathways for PHAs biosynthesis in R. eutropha and P. entomophila. PHAs biosynthesis occurred by Acetoacetyl-CoA synthesis (A) de novo fatty acid synthesis (B) and fatty acid β-Oxidation (C). The Acetyl-CoA, which is produced by metabolism and glycolysis of sugar and also fatty acid catalysis, as a vitally metabolic present in the all pathways. The phb genes encoded scl-PHA catabolic enzymes in order to PHB production, in contrast, the pha genes encoded catabolic enzymes to mcl-PHA such as