Aneesh, Balakrishna Pillai and Arjun , Jaya Kumar and Harikrishnan, Kumarapillai (2018) Enhanced production of poly(3-hydroxybutyrate) in recombinant Escherichia coli and EDTA-microwave-assisted cell lysis for polymer recovery. AMB Express, 8 (1). ISSN 2191-0855

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Abstract

Poly(3-hydroxybutyrate) (PHB) is a bacterial polymer of great commercial importance due to its properties similar to polypropylene. With an aim to develop a recombinant system for economical polymer production, PHB biosynthesis genes from Bacillus aryabhattai PHB10 were cloned in E. coli. The recombinant cells accumulated a maximum level of 6.22 g/L biopolymer utilizing glycerol in shake flasks. The extracted polymer was confirmed as PHB by GC-MS and NMR analyses. The polymer showed melting point at 171 °C, thermal stability in a temperature range of 0-140 °C and no weight loss up to 200 °C. PHB extracted from sodium hypochlorite lysed cells had average molecular weight of 143.108 kDa, polydispersity index (PDI) 1.81, tensile strength of 14.2 MPa and an elongation at break of 7.65%. This is the first report on high level polymer accumulation in recombinant E. coli solely expressing PHB biosynthesis genes from a Bacillus sp. As an alternative to sodium hypochlorite cell lysis mediated polymer extraction, the effect of combined treatment with ethylenediaminetetraacetic acid and microwave was studied which attained 93.75% yield. The polymer recovered through this method was 97.21% pure, showed 2.9-fold improvement in molecular weight and better PDI. The procedure is simple, with minimum polymer damage and more eco-friendly than the sodium hypochlorite lysis method.

Item Type:	Article
Uncontrolled Keywords:	Poly(3-hydroxybutyrate) Recombinant E. coli EDTA Microwave Cell lysis Polymer extraction
Subjects:	Environmental Biology
Depositing User:	Central Library RGCB
Date Deposited:	10 Apr 2019 07:19
Last Modified:	10 Apr 2019 07:19
URI:	http://rgcb.sciencecentral.in/id/eprint/723

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