| In the present thesis, nutritional and non-nutritional factors, surging fermentation techniques of a 16 liter anto fermenter and a 7 liter air-lift fermenter and extracting techniques of free radical scavenger of Ba02, a strain of Beauveria sp. were studied. Among 8 strians of Beauveria sp., Ba02 was found yielding highest free radical scavenger content. The carbon source experiment showed that commercial sugar, sucrose and glycerol were helpful to yielding free radical scavenger. Among them, commercial sugar was the best. Glycerol and commercial sugar as carbon sources could contribute to the synthesis of free radical scavenger. Amidst eight nitrogens, soybean powder and yeast extract were favorable nitrogen sources. But taken raw material and cost into account, soybean powder was the best. When initial pH was 8, orthogonal test with seven kinds of mineral compounds and growth promoters as test factors indicates that K.2HPO4 MnSO4-H2O and wort had significant effects on free radical scavenger at 99% level. For liquid surging fermentation conditions of Ba02, the optimal composition of medium was : commercial sugar 30g/L, glycerol 6ml/L, K.2HPO41 g/L, MnSO4 - H2O 0.006 g/L, wort 20 ml/L.pH as one of non-nutritional factors was studied with free radical scavenger yield and myceiial biomass as targets. The result showed that initial pH value as 8 would decrease in course of incubation and pH 4.5 was the optimal point at which pH was adjusted to 7.5 with autoclaved HC1 (1M) or NaOH (1M). Three gradients were set up in temperature experiment and the most suitable temperature for Ba02 was 25 C. The other optimal non-nutritional factors including seed ageN inocula> inoculated volumesand agitating speed were determined through an orthogonal experiment. The optimum culture conditions were as follows: temperature 25℃, seed aged 7 d, 25 ml/250 ml flask of culture volume, 5 % of inoculated volume, 180 rpm of agitating speed. Effects of optimal medium and incubation conditions on free radical scavenger were tested. In the view of synthesis of free radical scavenger, under the same optimal incubation condition, the optimal medium made the goal metabolite turnout advanced by 24.14 % although prolonging fermentation peak time by one day; Strain BaOl was superior to Ba02 by 7.4 %, which made it clear that BaOl was fitter for still fermentation than Ba02. The sieving of Beaweria sp.strains ,optimal medium and incubation condition increased free radical scavenger yield to a great extent by 26.5 % and cut short fermentation peak time by 11 d. So, the effect of optimization was distinct. Based on the surging fermentation experiments, submerged fermentation conditions of the 16 liter auto-fermenter and 7 liter bubble fermenter were studied. The result revealed that oxygen was important to Ba02 mycelial biomass and free radical scavenger. For 16 liter auto-fermenter, the condition that ventilation higher than 1:0.9(v/v/m) and impeller rotational speed higher than 450rpm benefitted fermentation.In search of an extracting technique of free radical scavenger, which was lower energy consumption and pollution, temperature, ratio of concentration, extracting solvent, extracting way, extracting time and ratio were optimized. The result revealed the excellent extracting technique was: concentration temperature 90 ℃, enrichment ratio as little as possible, extracting solvent CHsCOOCaHs, extracting ratio 1:10, extracting time 1 h.The rough extractor of Ba02 had good impacts on DPPH- scavenging effects among five samples including four kinds of healthcare medicines. Taken producing cycle and cost into account, Ba02 had great potential on factory production of free radical scavenger. The inhibitor of MAO of Ba02 was also primarily studied and the outcome showed there was some inhibitor of MAO in the Ba02 clarified culture broth whose generating curve was different from that of free radical scavenger. The effect of RCEF(ig) on "behavioural despair" experiment in mouse was significant at 99% level, which...
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