Polyhydroxyalkanoates (PHA)

Introduction:

Polyhydroxyalkanoates (PHA) are a class of polyesters produced by several groups of bacteria under unbalanced growth conditions as a mechanism to store excess carbon and energy, and they occur as water-insoluble inclusions in the cells (Anderson and Dawes 1990; Zinn et al. 2001). These polyesters have garnered worldwide interest because they are biodegradable (Ho et al. 2002; Lenz and Marchessault 2005; Lim et al. 2005), biocompatible (Zinn et al. 2001; Hazer and Steinbuchel 2007) and are produced by bacterial fermentation using renewable resources. Hence PHA has potential as alternative material for conventional petrochemical-based plastics.

Biobased materials such as polynucleotides, polyamides, polysaccharides, polyoxoesters,

A wide variety of different monomer compositions of PHA has been described, as well as their future prospects for applications where high biodegradability or biocompatibility is required. PHA can be produced from renewable raw materials and are degraded naturally by microorganisms that enable carbon dioxide and organic compound recycling in the ecosystem, providing a buffer to climate change.Although more than 300 different microorganisms synthesize PHA(Steinbüchel, A et al,1995, Kim et al,2001, Lenz et al,2005, Hazer et al ,2007), only a few, such as Cupriavidus necator (formerly known as Ralstonia eutropha or Alcaligenes eutrophus), Alcaligenes latus, Azotobacter vinelandii, Pseudomonas oleovorans, Paracoccus denitrificans, Protomonas extorquens, and recombinant E. coli, are able to produce sufficient PHA for large-scale production.

The objective of this study was to isolate and identification PHA-producing bacteria in different soils collected from Allahabad and characterization for Plant growth promoting traits for the enhancement of Rice seed germination under in Vitro