Primary Studies On Biotransformation Of Vanillin

The thesis focused on determination of vanillin, ferulic acid and other by-products of fermentation broth, the optimal production medium and culture conditions of Streptomyces L1936 for producing vanillin .The parameters of HPLC were determined. TLC was carried out for qualitative analysis. Spectrophotometery was used for quantitative analysis. The optimal conditions of enzyme pretreatment and extracting ferulic acid from rye bran were developed by orthogonal design theory. The optimal amount of enzymes was determined, that is . -amylase 40 /g raw material, 1398-proteinase 36 /g raw material, amyloglucosidase 400 /g raw material. The optimal technology was adopted to rye bran at 60 C for 6h with 1.0% concentration of sodium hydroxise to release ferulic acid 3.114g/L. Streptomyces L1936 could biotransformate the concentrated extract solution. The mount of vanillin in the broth was 0.174g/L. The optimization of fermentation media about the strain Streptomyces L1936 was researched. Different sorts of carbon and nitrogen resources, metal ions of inorganic salt were studied in the single factor experiments. Three ingredients (glucose, yeast extract, MgSO4 7H2O) ratio of media was optimized through Response Surface Analysis. The optimal concentrations of the factors were obtained: glucose 1.0g/L, yeast extract 1.0g/L, MgSO4 7H2O 0.2g/L.And the optimal media was as followed: glucose 1.0g/L, yeast extract 1.0g/L, MgSO4-7H2O 0.2g/L, Na2HPO4 4g, KH2PO4 1g, NaCl 0.2g, CaCl2-2H2O 0.05g, H2O 1000mL. The cultivation conditions of the strain Streptomyces L1936 was study and the optimal conditions were as followed: the inoculation size 6%, the fermentation temperature 37 C, a 500mL flask containing 50mL medium, the speed was 190r/min. The addition conditions of ferulic acid were studied. It was preferable that ferulic acid was added when the strain was in the period of stabilization. Fed-batch culture was adopted to relieve the toxic of ferulic acid to microorganism. The concentration of vanillin 7.246g/L was produced in flask and 10.51g/L vanillin was obtained in stirred tank fermentor.