Co-synthesis Of Polyhydroxyalkanoates And Ectoine Using The Moderately Halophilic Bacteria And Optimization Of Synthesis Conditions

As a kind of bio-synthetic plastic, PHA has the excellent properties of biodegradability and biocompatibility. These characters of PHA have made it widely used in many fields such as agriculture, medicine. It has great significance for the further study of PHA since the cost of production, separation and purification is too high to meet the demand of industrial production. The co-synthesis of PHB and Ectoine is a new way for PHB preparation which is low-cost and high efficiency.The co-synthesis of PHB and Ectoine from Halomonas venusta DSM4743 was indentified. The effect of different substrates and enzyme inhibitors on the synthesis of PHB from H. venusta DSM4743 was investigated and possible synthesis method was discussed. Partial sequence of the genes encoding PHA synthases PhaC from Halomonas halophila DSM4770 was cloned. In order to investigate the effects of the concentration of N, P, NaCl and different carbon sources on the synthesis of PHB, the fermentation conditions were optimized. The optimal conditions were yeast extract 0.1%, monosodium glutamate 5%, glucose 5%and NaCl 6%. A two-phase co-synthesis method was discussed, the synthesis of PHB and Ectoine was 4.17 g/L and 263.13 mg/L respectively when adding glucose and oxygen in the inducible synthesis phase.