Cassava Ethanol Concentration Fermentation Strains Breeding And Application Of Research

Fuel ethanol is a new recycling energy,has became an important aspect of the energy development.Cassave is a non-grain that considered as a promising raw material for ethanol fermentation.At present,the ethanol fermentation level of cassava is very low,so it is essential to select the appropriate stains in the process of ethanol fermentation.The main content of this work is listed as follows:Firstly,using cassava medium to cultivate the stains supplied by Henan Tianguan Enterprises Group Co.Ltd.Secondly,the research of physiological and biochemical characteristics of the selected strains.Thirdly,the optimization of the conditions of ethanol fermentation was carried out in this work.At last,study on the scale-up experiment of 50 L fermentation tank.Firstly,cassava medium was used to cultivate the stains,and screening several times to obtain a excellent stain,then,the stain was applied in ethanol fermentation,the ethanol concentration of the ending feed solution can be reached to 18.26 vol.%.The stains was named as TG and used in following experiments.Study on the physiological and biochemical characteristics of the selected strains.The results showed that the appropriate temperature was 33?,the pH was kept at 5.0,the properities of sugar,slat and alcohol resistance was better than that of original stains 1308.The stablility tests also showed that the TG strains owned good inheritance.The fermentation conditions of TG strains were optimized.The particle size of cassava was about 60 mesh,the liquids temperature was 90? and kept 2 h,the adding of diastatic enzyme was 240U/g and added by 2 times at the beginning and 16 h.Meanwhile,for the fermentation in 1 L bottle,the seed culture temperature was 30? and the fermentation temperature was 33 ?,the liquid volume was 500 mL and the inoculation amount occupied 30%of the liquid.In addition,the adding amount of urea,potassium dihydrogen phosphate and magnesium sulfate was 6 g/T,18 g/T and 7 g/T,respectively.The ending ethanol concentration could be reached to 19.1 vol.%.At last,study on the scale-up experiment of 50 L fermentation tank.The optimal condition of ethanol fermentation using cassava as material was obtained.The ventilation quantity was 0.5 vvm in the stage of 0-8 h of fermentation,the adding amount of urea was 9 g/kg and added 4 h later.The adding amount of diastatic enzyme was 180U/g and added by 4 times at 0,8,16 and 24 h.The ending ethanol concentration could be reached to 19.88 vol.%.Compared with the Nanyang 1308 starin,the TG strain showed better fermentation results,the alcohol volume amount ethanol concentration and starch utilization ratio were increased 20.41%,32%and 24.90%,respectively.In conclusion,the excellent strain was obtained according to the traditional methods,the conditions of the ethanol fermentation in 50 L fermentation fank was also optimized.This work can supply some reference for future scale-up production.