Invited Presentation: Seawater Based Microbial Synthetic Biotechnology

Industrial biotechnology based on microbial fermentations aims at producing chemicals, materials and biofuels to partially replace petrochemical routes. However, industrial biotechnology cannot compete with the petrochemical industries as it suffers from high consumptions on energy and freshwater, discontinuous processing, low product concentration and thus high product recovery cost as well as low substrate to product conversion efficiency. Therefore, to make industrial biotechnology competitive, we need develop fermentation platform technology which is energy and fresh water saving and run in a continuous way instead of a batch way.

To overcome these disadvantages of the traditional fermentation industries, seawater based fermentation technology has been developed based on Halomonas spp. Taking production of microbial bioplastics polyhydroxyalkanoates (PHA) as an example to show the advantages of this new technology. To lower the production cost of PHA, we have developed a seawater technology based on Halomonas spp. grown in seawater in an unsterile and continuous process. This new blue water technology achieves fresh water saving, energy saving and reduces process complexity combined with mixed substrates like kitchen wastes, it significantly reduces the production cost of PHA and its biofuels.

In this lecture, the most updated technology to reprogram the Halomonas spp. will be introduced. We have been able to assemble several multiple genes containing pathways in Halomonas spp. for production of various PHA molecules. The growth patterns of the Halomonas spps. have been changed to influence the shapes of Halomonas spps. from short rods to long fibers, even further to large spheres, allowing more PHA accumulation and easy product recovery. The technology has been pilot tested in industrial setting, it has been proven to be able to reduce PHA production cost at least 100%. The seawater technology should be able to improve the economic competitiveness of industrial biotechnology. We expect the technology can play an increasingly important role in the fermentation industries.

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