A study on medium chain length-polyhydroxyalkanoate accumulation in Escherichia coli harbouring phaC1 gene of indigenous Pseudomonas sp. LDC-5

Abstract

Aims: This study is mainly focused on the heterologous expression and accumulation of polyhydroxyalkanoates (PHA) in Escherichia coli.

Methods and results: PHA synthase gene (phaC1) from indigenous Pseudomonas sp. LDC-5 was amplified by PCR and cloned in E. coli (Qiagen EZ competent cells). The recombinant E. coli was analysed and confirmed for its expression of phaC1 gene by phase contrast microscopy, Western blot analysis and spectral studies (Fourier-transform infrared spectroscopy). It was further evaluated for its accumulation in different carbon and nitrogen sources. The accumulation of PHA (3.4 g l(-1)) was enhanced in the medium supplemented with glycerol and fish peptone compared to the other carbon and nitrogen sources used in this study.

Conclusions: This study would enable the reduction of cost of PHA production.

Significance and impact of the study: An important part of this study is that E. coli harbouring partial phaC1 gene could accumulate medium chain length PHA significantly. The results demonstrated that the E. coli strain could be a potential candidate for the large-scale production of polymer. The conditions for the higher yield and productivity will be optimized in the next phase using fermentation studies.