黑酵母(Aureobasidium pullulans)所分泌的胞外多醣體是一種線性直鏈高分子，名為普魯藍多醣(Pullulan)，因為結構與其他物理、化學性質特殊，廣泛的應用於食品、醫藥工業方面。 本論文是探討「光」此類的環境因子對於A. pullulans生產胞外多醣之影響。探討的方式是利用白光、紅光、藍光三種不同光波長的光源在不同光強度下對Aureobasidium pullulans發酵所產生的效應。 實驗結果發現於pH 4.8、攪拌式發酵槽中，所有光源均能夠加速碳源利用，藍光LED 600 lux、白光LED 200 lux、400 lux 則會對胞外多醣轉化率產生抑制的現象。而以白光 400 lux具有最大抑制性。低強度的藍光100 lux、200 lux能提升基質對產物胞外多醣轉化率與產率，基質對產物胞外多醣轉化率依序提升至0.41、0.45，為避光0.35的1.17、1.28倍；產率部分依序提升1.57、1.9倍。並且於胞外多醣產量最高值下，副產物黑色素含量分別為0.62、0.66 g/L，較避光組0.54 g/L 分別提升了15 %、22%。紅光200 lux、600 lux無助於基質對產物轉化率，均為0.31，略為下降11%；但於多醣產量最高值下，副產物黑色素含量分別為0.44、0.47 g/L，均約下降了20%。 以上發現照光會對Aureobasidium pullulans產生影響性，隨著不同波長的光源而有不同的效應。藍光能夠提升胞外多醣轉化率，可以降低發酵成本；而紅光能抑制黑色素產量，有助於降低純化多醣的成本。 Pullulan is a linear homopolysaccharide that is produced extracellularly by Aureobasidium pullulans. It has been processing in application of food industry and pharmaceutical industry because of it’s unique physical and chemical properties. My study was investigated the effect of light wavelength and intensity on the accumulation of extrapolysaccharides (EPS) by Aureobasidium pullulans. The fungus Aureobasidium pullulans was grown in white light, red light (640 nm) and blue light (470 nm) with difffernt intensity。 The fermentor is constant stirring tank reactor (CSTR) fermentations with constant pH of 4.8. All the radiation of light accelerated consumption of carbon source in the stirred tank. The pH is 4.8. LED blue light (200 lux) and white light (200lux、400 lux) would inhibit the yield of EPS significately. The white light (400 lux) has the highlest ability to inhibit the yield of EPS. Low intensity of blue light (100 lux、200 lux) could promote the yield coefficient of EPS and yields of melanin. These yield coefficient of EPS were 17% (0.41 g/g)、28% (0.45 g/g) higher than the dark group (0.35 g/g). These productivity of EPS are 57%、90% higher than the dark group. These yields of melanin were also 15% (0.62 g/L)、22% (0.66 g/L) higher than the dark group (0.54 g/L) at the maximum of EPS. The red light (200 lux、600 lux) could reduce the yields of melanin about 20% but no use on the yield of EPS. These findings suggest that the radiation of differential light could exert influences on Aureobasidium pullulans. The blue light could promote EPS and melanin. The red light could reduce the yield of melanin.
