Construction of recombinant Bacillus subtilis for production of polyhydroxyalkanoates.
ABSTRACT Polyhydroxyalkanoates (PHAs) are polyesters of hydroxyalkanoates synthesized by numerous bacteria as intracellular carbon and energy storage compounds and accumulated as granules in the cytoplasm of cells. In this work, we constructed two recombinant plasmids, pBE2C1 and pBE2C1AB, containing one or two PHA synthse genes, respectively. The two plasmids were inserted into Bacillus subtilis DB104 to generate modified strains, B. subtilis/pBE2C1 and B. subtilis/pBE2C1AB. The two recombinants strains were subjected to fermentation and showed PHA accumulation, the first reported example of mcl-PHA production in B. subtilis. Gas Chromatography analysis identified the compound produced by B. subtilis/pBE2C1 to be a hydroxydecanoate-co-hydroxydodecanoate (HD-co-HDD) polymer whereas that produced by B. subtilis/pBE2C1AB was a hydroxybutyrate-co-hydroxydecanoate-co-hydroxydodecanoate (HB-HD-HDD) polymer.
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ABSTRACT: Bacillus, generally regarded as safe, has emerged as a robust organism that can withstand adverse environmental conditions and grow easily to very high densities. Bacillus has been recognized for its biotechnological applications on an industrial scale. Recent efforts have shown the potential of Bacillus to generate biofuels (hydrogen), biopolymers (polyhydroxyalkanoates), and bioactive molecules (acyl-homoserine lactonases). Bacillus can be considered the dark horse in the race to generate sustainable energy, ecofriendly non-fossil fuel-based polymers, and bioactive molecules for use as therapeutics.Biotechnology advances 08/2013; 31(8). DOI:10.1016/j.biotechadv.2013.08.007 · 8.91 Impact Factor
Thesis: BIOSYNTHESIS OF POLY(3-HYDROXYBUTYRATE) USING MARINE BACILLUS MEGATERIUM UMTKB-1 By AMIRUL ARIF BIN ABDUL SHUKOR A PITA report submitted in partial fulfilment of the requirements for the award of the degree of Bachelor of Applied Science of Conservation and Management of Biodiversity SCHOOL OF MARINE SCIENCE AND ENVIRONMENT06/2014, Degree: Bachelor of Applied Science of Conservation and Management of Biodiversity, Supervisor: Dr. Kesaven Bhubalan
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ABSTRACT: Polyhydroxyalkanoates (PHAs) as an alternative to synthetic plastics have been gaining increasing attention. Being natural in their origin, PHAs are completely biodegradable and eco-friendly. However, consistent efforts to exploit this biopolymer over the last few decades have not been able to pull PHAs out of their nascent stage, inspite of being the favorite of the commercial world. The major limitations are: (1) the high production cost, which is due to the high cost of the feed and (2) poor thermal and mechanical properties of polyhydroxybutyrate (PHB), the most commonly produced PHAs. PHAs have the physicochemical properties which are quite comparable to petroleum based plastics, but PHB being homopolymers are quite brittle, less elastic and have thermal properties which are not suitable for processing them into sturdy products. These properties, including melting point (Tm), glass transition temperature (Tg), elastic modulus, tensile strength, elongation etc. can be improved by varying the monomeric composition and molecular weight. These enhanced characteristics can be achieved by modifications in the types of substrates, feeding strategies, culture conditions and/or genetic manipulations.Indian Journal of Microbiology 01/2015; DOI:10.1007/s12088-015-0528-6 · 0.83 Impact Factor