茁芽短梗霉P1012产普鲁兰多糖的条件优化

Optimization of Fermentation Conditions for Producing Pullulans in Aureobasidium pullulans P1012

研究了培养基组分(蔗糖、米糠和L-抗坏血酸)及发酵条件(pH、温度、接种量和转速)对茁芽短梗霉P1012(Aureobasidium pullulans P1012)产普鲁兰多糖的影响,以期提高普鲁兰多糖的产量。研究对培养基组分进行单因素试验及优化发酵条件,再结合正交试验考察了三因素(米糠、蔗糖和L-抗坏血酸)两水平对普鲁兰多糖产量的影响,从而优化茁芽短梗霉P1012发酵工艺,并通过上5 L发酵罐发酵培养验证。试验确定最佳培养基配方为蔗糖70 g/L、米糠3 g/L和L-抗坏血酸3 g/L。发酵条件控制为温度28℃、p H 5.0、接种量4%以及转速200 r/min。经5 L发酵罐培养后,测定普鲁兰多糖产量达到43.77 g/L,糖转化率为62.53%。发酵液pH由5.00升至6.56,黏度达到52.10m Pa·s,具有特别的芳香气味。获得茁芽短梗霉P1012的发酵工艺参数,为进入工业化生产提供依据。

In order to increase the pulluans productivity of Aureobasidium pullulans P1012, the effects of medium component（sucrose, rice bran, and vitamin C） and fermentation conditions（p H, temperature, inoculum size, and speed） on the pulluans＇ yield were investigated. The fermentation condition and medium component of high yield production were determined with single factor experiments. The effects of three extracting factors（sucrose, ricebran, and vitamin C） and the one＇s two levels on the pulluans＇ yield were studied through orthogonal test. Then fermentation technology of Aureobasidium pullulans P1012 was obtained, and validated by fermentation in 5 L fermenter. The optimum culture medium had been obtained with sucrose 70 g/L, rice bran 3 g/L and vitamin C 3 g/L. The optimal fermentation conditions were as followings： fermentation temperature 28 ℃, initial p H 5.0, inoculum 4% and speed 200 r/min. After 5 L fermenter culture, the yield of pullulan of strain P1012 was 43.77 g/L, the sugar conversion rate was 62.53%. During the fermentation, p H increased to 6.56 from 5.00. Viscosity of fermentation broth which had especial aroma smell was 52.10 m Pa·s. Termentation technology of Aureobasidium pullulans P1012 would provide basis for pulluans production in industrial scale.