Glycerol Conversion To 1,3-Propanediol By A Newly Isolated Microognism And Optimization Of Its Medium

1,3 - propanediol (1,3-propanediol, abbreviated as 1,3-PDO) is an important chemical raw materials,which could be used as monomer during the production of polyester, polyether, polyamide and other polymers,and would occupied the market to large extent. Particularly when the 1,3-PDO is used as synthesis polyester materials for PTT, due to the characteristicof good flexibility, resistant to pollution, and good coloring and good biodegradability, drawing growing concerns, as well as showing the bright future for mass production, so that research and development of 1,3-PDO is receiving increasing attention. The growing shortage of energy recently, the study on renewable resources as raw materials to produce bio-diesel has a positive practical significance, with charateristic of small environmental pollution and by-product glycerol for production of microbial transformation of 1,3-PDO. With increasing production of vegetable oil in developing countries and increasing appliance in the chemical industry, in the use of large quantities of glycerol in the world market and prices will gradually decline which give way to development and utilization of bio-technology and which render transforming glycerol into the products of high prices ( such as 1,3-PDO)to the focus of attention.In this experiment the crude glycerol was the by-product in the process of biodiesel during which the Swida were used as crude materials .During the process of producing bio-diesel , a large number of glycerol was manufactured .With the aim of better utilization of glycerol,the present experiment translate glycerol into of products of higher price (such as 1,3-PDO), in which 8 thalli with different morphology were picked up from the Betula forest soil. After the shake flask experiement, by the gas chromatography analysis, bacterial sx7 which can produce 1,3-PDO from glycerol was gained.By the experiment of cell morphology observation combined with physiological and biochemical experiments, was found as Gram-positive bacteria with the charateristic of non-spore, facultative anaerobes, contact-negative. Then Sx7 was preliminarily determined as intestinal microoganism after the sequential experiments of producing ammonia with Arginine, starch hydrolysis, gelatin liquefaction and growth conditionsSx7 for the good bacterial culture of 96h, anaerobic culture 96h, after the first aerobic anaerobic (each 48h) culture, found in the completely anaerobic conditions, the strain output of the highest, 17.18g / L, conversion rate of 52.00%. In order to make the strain disproportionation glycerol 1,3-PDO production output has been improved culture conditions for its trace elements, organic salt, inorganic salt, fermentation pH, culture time, culture temperature, such as a system. To determine the optimum fermentation medium is: glycerol 40.00g / L, KH2PO4 0.50 g / L, K₂HPO₄ - 3H₂O 1.00 g / L, (NH₄) 2SO₄ 3.00 g / L, CaC₁₂ ? 2H₂O 0.02 g / L, CaCO3 2.00g / L, yeast extract, 3.00g / L, most micro-elements solution 4ml / L, Fe2SO4 5.00mg / L, MgSO₄ - 7H₂O 0.05g / L. The strains of 1,3-PDO production of 25.03g / L, the conversion rate of glycerol to reach 75.76%. Optimization than the former, the output increased 7.85g / L, enhanced the conversion rate of 23.76%.