Biopolymer - A beginning towards back to nature

Abstract

Biopolymer is regarded as a polymer which can be biodegradable. Polyhydroxyalkanoates (PHAs) is one of the biopolymer which can be recovered from biomass. PHAs are naturally conserved in the cytoplasm of the bacterial cell during the growth. Bacteria/microbes store their energy from carbon sources in the form of hydrocarbons. Intracellular stored compounds are tightly linked with entire cell resulting difficulty of separation. The work aims to extract PHAs from biomass effectively. Chemical and mechanical separation of PHA can be done from biomass. A pretreatment of cells before chemical and mechanical separation is also effective for separation of PHA and has been carried out. Chemical extraction of PHA includes digestion of cell wall in acidic or alkaline medium and releasing PHA in broth, later sedimentation recovers PHA. In recent work different chemical methods were carried out to extract PHA of medium chain length. In one of these, sodium hypochlorite was used to denature the protein and chloroform was used for extraction of purified PHA. A recovery upto 96.6%, PHA by dried weight of cell, was obtained which is quite high comparing to reported literature. Other chemical disruption by sodium chloride, sodium hydroxide and hydrogen peroxide with and without pretreatment have also been carried out.