A Review on Bioplastic from Starch, Cellulose and Polyhydroxyalkanoates (PHA) Sources

Environmental and safety challenges have incited scientists to find a substitute for the petro-based plastics. Bio plastics can be produced either directly from an organism or they can also be extracted from plant based materials such as starch/cellulose sources. Starch and cellulose are the most abundantly available polysaccharide molecules. The most widely used PHA is Polyhydroxybutyrate (PHB), produced as a stored food by bacteria. The most common method used for extraction of starch is wet milling. The other methods include microwave-assisted extraction, pressurized solvent extraction, sonication, etc. The methods used for extraction of cellulose fibres are mechanical and chemical methods, soxhlet extraction, xylanase treatment etc. As PHA is being produced intracellularly, there is need to separate it from the biomass using effective extraction techniques. Solvent extraction technique is the most common and it can also be extracted by lysing the cell using sodium hypochlorite. Enzymatic digestion is also an effective technique but a selective one. Bio plastics can help overcome energy crisis and reduce the use of conventional fuels. The objective is to devise various extraction techniques for bio plastic production.The future directions are to improve the properties of bioplastics which will in turn increase the quality of plastics.