Research On US And European Sanctions Against Russia's Oil Sector In The Context Of The Russian-Ukrainian Conflic

In this paper,the waste of bamboo shoots shell（BSS）was taken as the research object.In order to increase the value of components in BSS,hydrothermal pretreatment was proposed to improve the efficiency of production,and the influence of hydrothermal pretreatment on the efficiency of enzymatic hydrolysis was investigated.On the basis,using BSS lignin to prepare sodium lignosulfonate surfactants to improve the efficiency of enzymatic hydrolysis,and the preparation conditions of sodium lignosulfonate and its influence on the enzymatic hydrolysis of auto-hydrolyzed BSS were investigated.Finally,investigated the effect of BSS XOS on the intestinal flora activity.The main research conclusions are as follows:（1）Hydrothermal pretreatment（autohydrolysis）combined with endo-xylanase hydrolysis of BSS to obtain glucose and XOS rich in xylobiose（X2）and xylotriose（X3）.The results showed the glucose yield of pretreated BSS residue reached 74.84%and it reached 88.4%after adding PEG.In order to obtain more valuable X2-X3 parts of XOS,endo-xylanase was used to pre-hydrolyze autohydrolysis（170℃,50 min）.After endo-xylanase hydrolyzed,the yield of XOS reached 25.6%,and the content of X2-X3 was 76.7%.In addition,the content of fermentation inhibitors in the auto-hydrolysate of hydrothermal pretreatment was low（0.7 g/L formic acid,2.6g/L acetic acid,0.7 g/L furfural）.On the basis of mass balance,32.1 g glucose and 6.6 g XOS（X2-X3,5.1 g）were produced by hydrothermal pretreatment coupled enzyme method with 100.0 g BSS as raw material.The results showed that hydrothermal pretreatment could effectively improve the enzymatic hydrolysis property of BSS,and the utilization degree of BSS resources could be improved effectively under the cooperation of enzymatic method.（2）The preparation of sodium lignosulfonate（SL）by sulfonation was proposed to solve the problem on the utilization of BSS enzymatic hydrolysis residue.The results showed that the lignin sulfonation rate reached 45.8%after reaction at 100℃for 3 h with the solid-liquid ratio of 1:10,0.08 M CH₂OHSO₃Na and 10g lignin.In addition to studying the condition of SL production,the significant characteristics of SL which was identified as a surfactant,such as enzymatic hydrolysis property,critical aggregability（CAC）,sulfonic acid group content and Zeta potential,were also studied.The results showed that the hydrolysis efficiency increased from 74.8%to 80.8%and the content of free protease increased from 3.38 mg/m L to 4.03 mg/m L with the addition of 0.075 g/g sodium lignosulfonate.（3）In order to investigate the physiological activity of BSS XOS,which was applied to human intestinal flora culture experiment.After 48 h anaerobic culture of intestinal flora,the results showed that utilization rate of the LDX and XOS reached 100%and 90%,organic acid metabolism increased by 6.5 and 4.7 times,bacterial proliferation increased by 2.25 and 1.81 times,and the abundance and richness of intestinal flora were significantly improved.In addition,according to the experimental results significantly XOS and LDX（X2-X3 as the main components）have the ability to improve human immunity and digestion.XOS is better at improving human digestion;LDX has significant inhibition of pathogenic bacteria and has more potential to improve host immunity.