The bioextraction of bioplastics with focus on polyhydroxybutyrate: a review

Use of bioplastics such as polyhydroxybutyrate (PHB) is increasing steadily. PHB extraction methods including solvent extraction and chemical digestion surfactant require the harmful reagents and result in severe quantitative and qualitative environmental and economic losses. Due to the friendly properties, biological extraction methods (called bioextraction methods) are gaining more attention to PHB extraction. Bioextraction methods can reduce the serious concerns in environmental pollution and cost by green tools such as genetic and metabolic engineering of PHB-accumulating cells in order to self-disrupt, induce, and modify predatory bacteria, and the utilization of mealworm digestive system. Through biotechnology mechanisms, a purified PHB biopolymer can be extracted by manufacturers in a eco-friendly system, while water and acetic acid can then be used for pre-treatment other than SDS and chloroform. As in many aspects of bioextraction, the cell engineering is accompanied by the modification of culture condition and feedstocks in order to bypass conventional approaches and their drawbacks, although these problems are yet to be solved, it can, however, be reduced by increasing the use of biotechnological approaches in bioextraction methods. The integration of biological with conventional approaches can decrease environment limitations and costs through genetically modified producers and culture optimization, and therefore establishing suitable and commercially viable extraction methods. However, PHB bioextraction through green technology may be advantageous over conventional methods with maximum impact on human health and environment. This review discusses about using bioextraction methods as green technologies for PHB extraction from bacterial producer cells with less environmental limitation.