1. Analyse the progress in the development and use of a named bioploymer. This anslysis should name the specific enzyme(s) used or organism used to synthesise the material and an evaluation of the use or potential use of the polymer produced related to it’s properties.
Progress Analysis: - Bacteria first used to make PHB in 1925 at Pastuer Institute in Paris. - In 1970’s adopted by Imperial Chemical Industries (ICI) – Alcaligenes Eutrophus grown in fermentation vats with Molasses - The bacteria is then starved of nutrients (glucose and nitrogen) – PHB is produced as an energy store for the bacteria. - In 1980’s Maddison University (Virgina) successfully cloned the 3 genes of A. Eutrophus that control PHB production and transferred them to Escherichia coli – an easier bacteria to work with allowing easier manipulation of the polymer depended on the need. - In 1990’s the 3 genes were cloned into sugar beets and turnips – much larger scale production of polymer. Work continuing (with Monsanto – company bought patent) into cloning genes to corn.
Advantages of PHB - Can be manipulated genically therefore can be used for many things - Hard, inflexible – used in medicine for sutures and stabilization of healing bones. - Soft, flexible, lightweight – disposable nappies, plastic bags, cling wrap, bottles and packaging. - Also Biodegradable – can be used in landfill etc. And breakdown naturally.
Disadvantages of PHB - Costly four times as much as polyethylene (it’s major competitor) – cheaper to produce necessary materials from petrochemical industry. - Large scale production in early stages.
Evaluativve conclusion: - PHB has huge potetial as polymer for future – biodegradable, ease of manipulation. - Work must be done to make it cheaper and make large-scale production easier. - We must do this as petrochemical industry supplies become scarce
Bibliography: en.wikipedia.org/wiki/Polyhydroxybutyrate www.greenplastics.com/.../index.php?title=Polyhydroxybutyrate www.scielo.br/scielo.php?pid=S1516...script=sci_arttext