| Using Sargassum thunbergi as a raw material, this paper studies the influencing factorsin the process of microbial fermentation, and making ethanol production more than3.0%-4.0%of the dry weight of the Sargassum thunbergii. At last, it explores the Sargassumthunbergii in the cellular level by observing changes of algal cells in the process of hydrolysisand fermentation.First of all, ethanol production from Sargassum thunbergii was carried out to optimizethe best fermentation temperature, pH and time, content of cellulose enzyme and yeastconcentration. At last a fermentation process was established.The results found that the optimal temperature is25℃to30℃and fermentation pH valueis the range of6to8in the process of fermentation. When don’t adding cellulose enzyme, thefermentation period is for3to4days. But when adding cellulose enzyme, the fermentationperiod is6to7days. Cellulose enzyme content is the main influencing factor the productionof ethanol when yeast concentration is low. When yeast concentration is high (30%40%), theyeast is the main factor that influence the production of ethanol. The adding of two kinds ofcellulose enzyme in Sargassum thunbergii can significantly enhance the production of ethanolafter fermentation. The ethanol production of using cellulase R-10in Sargassum thunbergii ishigher than using cellulase Aladdin. Glycerin is a main impurity in the fermentation process.There are also some other impurities. For example, methanol and other fusel, but theircontents are very small. The maximum yield of ethanol (51.32ml/kg) after fermentation isreaching4.02%of the dry weight of the Sargassum thunbergii.Secondly, exploring the changes of Sargassum thunbergii by observing its cell structurein the process of hydrolysis and fermentation. The experimental results showed that theadding of two kinds of cellulose enzyme have no visual impact on yeast cells, and the cellwall of yeast cells have not been broken. The changes of cell structure in Sargassumthunbergii are mainly concentrated in the hydrolysis stage. While, there are no obviouschanges with the increase of fermentation time. Adding two kinds of cellulose enzymeimprove the effect of hydrolysis. With the increase of hydrolysis time, the Sargassumthunbergii cells are constantly broken, and a large number of cell contents flow out. There arealso a lot of pieces of algal cells in the solution. The surface of Sargassum thunbergii cells is algin which is the biggest obstacle in the process of hydrolysis, and it is the direction thatresearchers need to breakthrough in the future. |
