The Study On Degradation Efficiency And Degradation Model Of Straws By Inonotus Obliquus

Lignocellulose is the main renewable resources on earth at present,composition of cel ulose,hemicel ulose and lignin,due to lignin wrap around cel ulose and hemicel ulose form structure of recalcitrant,led to very low utilization rate of lignocellulose.Currently,white-rot fungi is the only that can direct degradation of lignocellulose by fungi in biological pretreatment and it has a very high value in biological pretreatment.In recent years,although there are some researches on how to improve some type white rot degradation lignocellulose efficiency,how to improve conversion rate,and how to produce degradation enzyme efficiently,the selective degradation of white rot fungus is still in the research stag.For the reaserch on other white rot,such as fungus Inonotus obliquus in nature and in the submerged culture,of which lignocellulose degradation models,degradation efficiency and degradation enzyme remains blank.This thesis is about the degradation efficiency and degradation model of liquid fermentation of Inonotus obliquus on different types lignocellulose materials(such as wheat straw,rice straw,corn stover).which aimed to discover the white rot fungi with new high effective degradation and selective degradation of lignin.This paper uses the chemical analysis named van Soest method to analyze the dynamic degradation rate of cel ulose,hemicel ulose during the process of fermentation of lignocellulose material lignin,and the lignocellulose degradation process of chemical structure,surface structure and degree of crystal inity were characterized by using Fourier transform infrared spectroscopy(FTIR),scanning electron microscopy(SEM),X-ray diffraction(XRD).Meanwhile,it also studied the dynamic production of lignocellulose-degrading enzymes as well as the relationships on lignocellulose degradation efficiency in the system of liquid fermentation of Inonotus obliquus.Objective of the study:1.Explore the degradation mode and heterogeneity of Inonotus obliquus in different types liquid fermentation of straw lignocel ulose,clear selective degradation of Inonotus obliquus and enzyme mechanisms.2.Explore the main composition and the production pattern of enzymes of Inonotus obliquus(lignin-degrading enzyme,cel ulose-degrading enzyme,cel ulosedegrading enzymes)which are produed by different types of straw lignocelluloseinduced liquid fermentation of lignocellulose-degrading.Experiments results show that:1.Three kinds of lignocellulosic materials can promote the growth of mycelium of Inonotus obliquus and the effect is very significant.Wheat straw,rice straw,corn stover on the 8th day with the maximum promotion rate come to 20.1%,9.7%,6.9%,respectively.It may be due to the degraded cel ulose,hemicel ulose in lignocellulose by Inonotus obliquus,and as a carbon source nutrients for the mycelia grow fast.2.In the early fermentation,the Inonotus obliquus has a selective degradation of lignin on wheat straw,but on rice straw and corn stover lignocellulose has no selective.After 12 days,Inonotus obliquus degrades wheat straw,rice straw,corn stalk lignin with the degradation rates 72.0%,38.9%,47.1%,respectively.Inonotus obliquus has highly selective when the Initial lignin content of straw lignocellulose at around 15% in wheat straw.3.FTIR method determined Inonotus obliquus degradation rate of each component of lignocel ulose by ratio of characteristic peak,further identification of Inonotus obliquus degradate wheat straw have selective degradation of lignin,and the degradation of rice stalks,corn stover have no selective.XRD results show as wheat straw,rice straw,corn stover show a certain degree of crystal inity of lignocellulose decreased in the fermentation process,this description liquids fermentation Inonotus obliquus can able to degrade crystal ine cel ulose of lignocellulose material,which will be conducive to the further degradation of cel ulose.SEM results showed that wheat straw,rice straw,corn stover lignocellulose in liquid fermentation of Inonotus obliquus 6 days later,surface degradation of areas such as cracks,holes,faults arise.Because of Inonotus obliquus have selectivity degradation of lignin in the early fermentation,the experiment on wheat straw SEM analysis showed that found wheat straw surface holes and appears empty in 2 days,verified straw lignin Inonotus obliquus selective degradation of lignin.4.On 12 days in the fermentation process,System study on fermentation of Inonotus obliquus with wheat straw,rice straw,corn stover,three different types of lignocellulose secretion of ligninolytic enzymes,cel ulose-degrading enzyme,cel ulose-degrading enzyme producing laws.Which added wheat straw fermentation Inonotus obliquus lignin degradation enzyme LiP and MnP enzyme activity are above added rice straw and added corn strover enzyme activity,LiP and MnP enzyme activity almost increased than added rice stalk and added corn straw31%,88% and 121%,131%,respectively.Lignin-degrading enzyme LiP and MnP enzyme activity is very high in early the fermentation,this may be related to lignocellulose structure,cel ulose and hemicel ulose are surrounded by lignin,break down the lignin resistance to take precedence over degradation of cellulose and hemicellulose.In short,Inonotus obliquus has an efficient degradation of lignocelllose in fermentation treatment different types of lignocellulose.For straw lignocellulose,the effect is the best with the maximize lignin degradation,but degradation of cel ulose and hemicel ulose in straw is relatively less.What’s more,the straw cel ulose crystal inity is decreased by Inonotus obliquus which has the selective degradation on wheat straw lignin as well,especially in the beginning of fermentation.