The Study Of Lignocellulose Biodegradation In Sapogenin Solid Residue

Using Bio-refining technology to degrade lignocellulose is an availably solution tothe resources and environmental problems. Incomplete pretreatment low efficiency andhigh cost are three major limiting factors during the process of enzymatic hydrolysis oflignocellulosic biomass. Looking for environmental protecting and effective pretreatmentmethods is necessary and important. In this papers，diosgenin solid residues as theexperimental materials, five different kinds of pretreatment on residues degradation effectwas studied. And diosgenin extraction from diosgenin solid residues was studied toachieve the max utilization of diosgenin solid residues. Following achievements areobtained.1. We determined the pretreatment of diosgenin solid residues and optimized thepretreatment process. We comparatively studied the result of chemical pretreatment,microwave pretreatment, steam-explosion pretreatment, microbial pretreatment andsteam-explosion combined microbial pretreatment. Found that steam-explosion combinedmicrobial pretreatment is better than traditional chemical pretreatment as it takes less timeand produce less pollution. By optimize the pretreatment process, best pretreatmentprocess was confirmed. Maintain the steam pressure to0.28MPa keep ten minutes thenreduce it to zero rapidly. Then inoculate bacillus HR1cultivate two hours in the conditionof38℃and140rpm. The Total weight loss rate of diosgenin product residues is52.6%and the sugar yield is53.2%which is43.2%and38.2%higher than the residues that didnot receive any pretreatment.2. Trough the study of diosgenin extraction from diosgenin solid residues we foundthat Multiple pretreatment and alkali pretreatment have the highest diosgenin extractionrat (29.67%and32.33%). And by analysis the relationship between removal rat of threecomponents of the residues and diosgenin extraction rat we found that cellulose removalrat influence diosgenin extraction most. The more cellulose removed the higher diosgeninextraction rat we can get.3. Evaluate the saccharification liquid of diosgenin solid residues: We uses.cerevisiae to investigate the liquid’s influence on glucose usage, thalli wet weight and ethanol production of s.cerevisiae during fermentation. Confirm that s.cerevisiae canutilize all the glucose of sacchrification liquid and the diesgenin in liquid did not influences.cerevisiae wet weight and ethanol production very much.To sum up, multiple pretreatment was optimized. The enzymatic hydrolysis ofresidues’ cellulose and hemicelluloses is increased. When compared with otherpretreatment it has higher enzymatic hydrolysis rate and diosgenin extraction rate, lowerenvironment pollution. Evaluation of the saccharification liquid confirmed that thesaccharification liquid can be used to s.cerevisiae fermentation. Multiple pretreatmentwhich combined steam explosion and microorganism pretreatment is an efficiency andeco-friendly pretreatment, which has a great potential for efficiently utilize of diesgeninsolid residues.