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3-hydroxypropionic acid（3-HP） has many excellent chemical properties.It is an important potential compound for chemical engineering and a good intermediate to synthesize lots of valuable compounds.In this paper,fermentation production process of 3-HP by Candida Rugosa has been studied.Firstly,an assay method of 3-HP has been founded.The optimal separation conditions are as follows:differential scanning calorimeter,the chromatographic column is Diamonsil C18（4.6×250 mm,5μm）,mobile phase is 5%methyl alcohol with 0.005 mol/L sulfuric acid,flow rate of 1.0 mL/min,column temperature at 45℃,the injected sample is 5μL. 3-hydroxypropionic acid,lactic acid and propionic acid are completed separated at this chromatographic condition.And the calibration curve is linear（r=0.99998） within the range of 0～324 mg/mL for 3-hydroxypropionic acid.The recovery is 98.04%-100.06%,the detecting limit is 5μg/mL,and RSD（n=5） is 1.08%.Secondly,for the same purpose,the GC-2010 has been used to analyses the components and the content of fermentation and the analyzed conditions are optimized in the experiment.Optimization condition is FID probe,GC-Solution data-processing workstation, AT-FFAP（30 m×0.32 mm×0.5μm） capillary column,injection-entrance temperature:200℃,FID temperature:200℃,warming procedures: 99℃-1 min,80℃/min-160℃-0.5min,2℃/min-162℃-0.5min,20℃/min-180℃-0.5 min,carrier gas:Nitrogen,cross-flow mode:linear velocity:30 cm/sec,H2 flow:40 mL/min,air flow:400 mL/min,tail blow:30 mL/min, using split injection mode,split ratio:100,injection volume:1μL.The results show that:this method has the advantage of short test time,high accuracy,good separation efficiency and repeatability,the recovery rate is more than 98%,and RSD is 1.05%.Thirdly,a Candida rugosa which producing 3-hydroxypropionic acid is mutagenesis with NTG and UV,and a mutant C3 is obtained.The productivity of the 3-hydroxypropionic acid of C3 amounts to 0.55 mg/mL,which is 3.06 times compared with the original strain.Then the components of the fermentation medium were optimized.The optimum medium consisted of glycerol 2.0%,yeast extract 0.6%,wort 0.9%, （NH4）2SO4 1.5%,KH2PO4 0.9%,K2HPO4 0.3%,MgSO4·7H2O 0.3%, FeSO4·7H2O 0.003%,pH 6.0-6.5,optimal temperature 30℃and the optimum cultivation time is 72 hours.Then Fermentation condition of producing Propionic Acid has been studied,and the optimum culture condition is glucose 2.5%,yeast extract 2.0%,Peptone 3.0%,CoCl2·6H2O 11 mL（6 ppm）,NaCl 0.5%,pH 7.0-7.5,seed-culture time:4～5d,inoculation:10%,fermentation:7～9d.Finally,through the results of the two-stage batch mixed cultures of Propionibacterium acidipropionici and Candida rugosa,a feasible technics of producing 3-hydroxypropionic acid has been founded by mixed culture.It has been confirmed that the optimal join-time of Candida rugosa is 9.5 d,inoculation 15%,and the optimal temperature is 30℃.Under the condition,the productivity of the 3-hydroxypropionic acid amounts to 2.16 mg/mL,which is 2 times compared with 0.73 mg/mL in single culture.Comparing with the single culture,the mixed culture increase the production of 3-hydroxypropionic acid and decrease the cost,and also has the advantage such as low condition,less outgrowth,environment protected,and so on.
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