Xylo-oligosaccharides preparation through acid hydrolysis of hemicelluloses isolated from press-lye

The preparation of xylo-oligosaccharides(XOSs)through hydrolysis of hemicelluloses was studied.The hemicelluloses were isolated from the press lye discharged in the production of viscose,which contained about 30%xylan.Then,a factorial experimental design was applied to compare the influences of several factors including the concentrations of sulphuric acid and hemicelluloses,the duration and temperature of the hydrolysis,on the conversion of xylan,and the selectivity for the product–XOSs.The results showed that the hydrolysis duration affects the yield of XOSs to the greatest extent.It is difficult to obtain a high yield of XOSs with sulphuric acid as the hydrolysis catalyst.

Separation of xylo-oligosaccharides from enzymatic hydrolytes using membrane reactor

The time course of xylo-oligosaccharides concentration and xylo-oligosaccharides yield in the separation of xylo-oligosaccharides from enzymatic hydrolytes was studied using a membrane reactor with constant permeate flux of 4 L·m -2 ·h -1 . The results show that xylanases retain 90% of its activity in the reactor. The concentration of xylo-oligosaccharides achieves the maximum, about 5.48 g/L in 30 min. The difference of xylo-oligosaccharides in the retentate and permeate stream is low, <0.62 g/L, therefore it can permeate through membrane. Under the operating conditions that xylan concentration is 30.0 g/L, pH 5.0, operating pressure 16 kPa, temperature 48 ℃, feed velocity 400 mL/min, reaction volume 400 mL, enzyme dosage 10%(volume fraction), dilution rate 1 h -1 , and enzymatic hydrolysis time 195 min, the yield of xylo-oligosaccharides reaches 31.69%.

Effects of xylanase,protease,and xylo-oligosaccharides on growth performance,nutrient utilization,short chain fatty acids,and microbiota in Eimeria-challenged broiler chickens fed high fiber diet

A 21-d experiment was conducted to study the effect of xylanase,protease,and xylo-oligosaccharides on growth performance,nutrient utilization,gene expression of nutrient transporters,cecal short-chain fatty acids(SCFA),and cecal microbiota profile of broilers challenged with mixed Eimeria spp.The study utilized 392 zero-d-old male broiler chicks allocated to 8 treatments in a 4×2 factorial arrangement,as follows:corn-soybean meal diet with no enzyme(Con);Con plus xylanase alone(XYL);Con plus xylanase combined with protease(XYL+PRO);or Con plus xylo-oligosaccharides(XOS);with or without Eimeria challenge.Diets were based on a high-fiber(100 g/kg soluble fibers and 14 g/kg insoluble fibers)basal diet.At d 15,birds in challenged treatment were gavaged with a solution containing Eimeria maxima,Eimeria acervulina,and Eimeria tenella oocysts.At d 21,birds were sampled.Eimeria depressed(P<0.01)growth performance and nutrient utilization,whereas supplementation had no effect.There were significant Eimeria×supplementation interactions for the sugar transporters GLUT5(P=0.02),SGLT1(P=0.01),SGLT4(P<0.01),and peptide transporter PepT1(P<0.01)in jejunal mucosa.Eimeria challenge increased the expression of GM-CSF2(P<0.01)and IL-17(P=0.04)but decreased(P=0.03)IL-1βexpression in the cecal tonsil.Eimeria×supplementation interactions for cecal acetate,butyrate,and total SCFA showed that concentrations increased or tended to be greater in the supplemented treatments,but only in non-challenged birds.Birds challenged with Eimeria spp.had higher concentrations of isobutyrate(P<0.01),isovalerate(P<0.01),and valerate(P=0.02)in cecal content.Eimeria challenge significantly(P<0.01)decreased the microbial richness and diversity,and increased(P<0.01)the proportion of Anaerostipes butyraticus,Bifidobacterium pseudolongum,and Lactobacillus pontis.In conclusion,Eimeria infection depressed growth performance,nutrient utilization with regulating nutrient transporters.Furthermore,Eimeria challenge shifted the microbial profile and reduced microbial richness and diversity.On the other hand,enzyme supplementation showed limited benefits,which included increased concentrations of SCFA.

Xylo-Oligosaccharide Preparation through Enzyme Hydrolysis of Hemicelluloses Isolated from Press Lye

The emerging food additive, xylo-oligosaccharide(XOSs), was prepared through enzymatic hydrolysis of hemicelluloses isolated from press lye. Two of the three experimental enzyme preparations presented favourable effects, while the other one consisting of the nominal enzyme preparations with high enzyme activity was found to have poor catalytic effects. The conversion of xylan exceeded 40% and the selectivity for XOSs reached 90% when the temperature, hemicellulose concentration, dosage of enzymes, and hydrolysis time were 40?C, 100 g/L, 1 ku/g, and 4 h, respectively. Xylo-oligosaccharide preparation through enzymatic hydrolysis of hemicelluloses isolated from press lye was proved to be a feasible process to utilize the by-product of the lye regeneration, which will substantially improve the economy of the lye regeneration and recycling.