RESUMO
Twenty nine environmental samples were screened for the presence of anaerobic microorganisms fermenting glycerol with 1,3-propanediol as a final product. Seven samples were then selected for the next step of our research and eight bacteria strains were cultured anaerobically. Seven of them produced 1,3-propanediol with a yield of 0.47-0.58. Six of the the isolated microorganisms were then classified as Clostridium butyricum (four strains), C. lituseburense (one strain), and C. sartagoforme (one strain). We suggest that of all these strains C. butyricum 2CR371.5 is the best 1,3-propanediol producer as producing no lactate as a by-product and growing well on a glycerol-containing medium.
Assuntos
Clostridium butyricum/isolamento & purificação , Microbiologia Ambiental , Glicerol/metabolismo , Propilenoglicóis/isolamento & purificação , Sequência de Bases , Butiratos/metabolismo , Cromatografia Gasosa , Cromatografia Líquida de Alta Pressão , Clostridium butyricum/classificação , Clostridium butyricum/genética , Clostridium butyricum/metabolismo , Meios de Cultura/metabolismo , DNA Bacteriano/genética , DNA Ribossômico/genética , Fermentação , Dados de Sequência Molecular , Filogenia , Propilenoglicóis/metabolismo , RNA Ribossômico 16S/genética , Alinhamento de Sequência , Especificidade da EspécieRESUMO
1,3-propanediol is used as a monomer in the production of some polymers e.g. polytrimethylene terephthalate used in the production of carpets and textile fibers and in the thermoplastics engineering. However, the traditional chemical synthesis is expensive, generates some toxic intermediates and requires a reduction step under high hydrogen pressure. Biological production of 1,3-propanediol could be an attractive alternative to the traditional chemical methods. Moreover, crude glycerol which is a by-product of biodiesel production, can be used. We constructed a recombinant Escherichia coli strain producing 1,3-propanediol from glycerol by introducing genes of the dha operon from Clostridium butyricum 2CR371.5, a strain from our collection of environmental samples and strains. The E. coli strain produced 3.7 g of 1,3-propanediol per one litre of culture with the yield of 0.3 g per 1 g of glycerol consumed.
