连续微通氧浓醪乙醇发酵研究

Preliminary Study on Ethanol Fermentation with Very High Gravity and Micro-Aeration Technologies

为了提高浓醪酒精发酵效率,以高浓度木薯粉浆液化滤液为原料,对微通氧浓醪酒精发酵过程进行了研究。在搅拌式5 L发酵罐中,通过对连续通风速率分别为0、0.04、0.08、0.16、0.24、0.35 L/min的高浓度液化滤液酒精分批发酵过程分析表明,最佳通风策略为:以通风速率0.08 L/min进行酒精发酵,酵母细胞密度达到5.40×108个/m L,发酵效率为90.00%,与未通风发酵相比分别提高了56.52%和2.45%。总之,在浓醪酒精发酵过程中微通氧能够提高酵母细胞活性,进而提高发酵效率。

Ethanol is widely used in renewable fuels ,chemical engineering,medicine and food industry. In developed countries there is a growing trend towards employing modem technologies and el？. cient bio-energy conversion using a range of biofuels. In order to improve Very High Gravity （VHG） ethanol fermentation efficiency the optimization process of VHG ethanol fermentation from liquefied VHG cassava mash filtrate with micro-aeration were investigated in this thesis. Changes of fermentation parameters during the ethanol fermentation from VHG liquefied starch filtrate with aeration rate （0,0.04,0.08,0.16,0.24,0.35 L/min） by Saecharomyees cerevisiae GGSF16 under batch condition in a 5-L bioreactor were studied. The optimum condition for ethanol fermentation was shown as a continuous aeration rate of 0.08 L/min. The verification experiments under the optimum condition clearly indicated that the aeration strategies improved ethanol production. Thebiomass and fermentation efficiency were 5.40× 10^8 cells/mL and 90.00%, respectively, representing about 56.52% and 2.45% increase compared to anaeration fermentation. In conclusion, micro-aeration can improve VHG ethanol fermentation efficiency because it can enhance cell viability.