A highly active GH11 xylanase from Penicillium sp. L1 with potential applications in xylo-oligosaccharide production / 生物工程学报

Xylanase is a high-profile glycoside hydrolase with applications in brewing, feed, pharmacy and bioenergy industries, but most of xylanases are in active below 30 ℃. In order to obtain low temperature active xylanase, a xylanase gene, XYN11A, was cloned from Penicillium sp. L1 and expressed in Pichia pastoris GS115. After purification and enzyme assay, optimal pH and temperature were determined to be 3.5 to 4.0 and 55 ℃. This enzyme was stable at acid and neutral condition (pH 1.0 to 7.0) or under the treatment of 40 ℃ for 1 hour. This xylanase displayed strong resistance to all tested ions and chemicals. Noteworthily, XYN11A maintained a higher activity of 6 700 U/mg than a lot of GH11 xylanase, and demonstrated higher activity (24% to 58%) at lower temperature from 20 to 40 ℃. After beechwood xylan hydrolysis for 16 h, the hydrolysates consisted mainly of xylobiose, xylotriose and xylotetraose and barely of xylose, thus XYN11A could be used for the production of prebiotic xylooligosaccharide. Possessing the features of acidophilic, highly active at lower temperature and oligosaccharide production, XYN11A demonstrated great potential in food and feed industrials.

Effect of xylooligosaccharide-sugar mixture on defecation frequency and symptoms in young women with constipation: a randomized, double-blind, placebo-controlled trial / 한국영양학회지

PURPOSE: To investigate the effects of the intake of xylooligosaccharide-sugar mixture (XOS) on defecation frequency and symptoms in 56 young women (mean age of 22.1 years old) with constipation. METHODS: Two experiments were conducted. In experiment 1, a randomized double-blind study was performed to evaluate the effect of 6 weeks' intake of 10 g sucrose containing 7% xylooligosaccharide or 10 g sucrose on constipation. In experiment 2, 24 g coffee mixture containing 12.8 g plant cream and 11.2 g xylooligosaccharide-sugar mixture was consumed by the subjects. During the study, the clinical efficacy was assessed by using a daily diary. The subjects indicated the number of frequencies they defecated in a day and the clinical symptom scores. RESULTS: In experiment 1, the mean frequency of defecations was 2.07 in the pretreatment week and increased significantly to 4.05, 4.42, 4.84, 4.84, and 4.05 in weeks 2 to 6 of XOS intake, in comparison with the 3-3.67 with sucrose intake (sucrose, SUC). In experiment 2, the mean frequency of defecations significantly increased from 2.47 in the pretreatment week to 4.11-5.67 in weeks 1-6 of XOS intake. The occurrence of very loose or loose stools in the XOS group was significantly increased in weeks 5 and 6, compared with the pretreatment week and SUC group. XOS intake significantly alleviated the abdominal displeasure and feeling of residual stool leftness in weeks 2, 3, 5, and 6, while SUC did so in weeks 4 and 6 (p < 0.05). The coffee mixture containing xylooligosaccharide-sugar mixture reduced the abdominal displeasure and feeling of residual stool leftness from week 3 until the end of the experiment (p < 0.05). CONCLUSION: Our results suggest that xylooligosaccharide-sugar mixture intake was effective, without adverse effects, for the alleviation of constipation in the young women in this study.

Effect of different levels of xylooligosaccharide in sugar on glycemic index and blood glucose response in healthy adults / 한국영양학회지

PURPOSE: In the present study, we aimed to evaluate the effect of sucrose containing 2 different levels of xylooligosaccharide on the glycemic index (GI) and blood glucose response in healthy adults. METHODS: Healthy adults (4 male participants and 6 female participants, n = 10) were randomized to receive glucose, sucrose, sucrose containing 7% xylooligosaccharide active elements (Xylo 7), or sucrose containing 10% xylooligosaccharide active elements (Xylo 10). Each participant was administrated one of these materials once a week for 8 weeks and an oral glucose tolerance test was performed. RESULTS: We found a reduction in the glycemic response to sucrose that included xylooligosaccharide active elements (Xylo 7 and Xylo 10). The glycemic indices of sucrose, Xylo 7 and Xylo 10 were 68.9, 54.7, and 52.5, respectively. The GI values of Xylo 7 and Xylo 10 were similar to that of foods with low GI. The percentage reduction of GI value caused by sucrose containing xylooligosaccharide active elements was significantly different and dose-dependent as compared to that caused by sucrose alone (p < 0.05). The reduction in the glycemic response to Xylo 7 and Xylo 10 was 21% and 24%, respectively, as compared to the glycemic response to sucrose. The attenuation of the glycemic response to Xylo 10 tended to be higher than that for Xylo 7 when the percentage of body fat was increased. CONCLUSION: These results demonstrated that xylooligosaccharide active elements may be effective in protecting humans against overconsumption of sucrose.

Effects of xylooligosaccharide-sugar mixture on glycemic index (GI) and blood glucose response in healthy adults / 한국영양학회지

PURPOSE: The objective of this study was to investigate the effects of xyloologosaccharide (XOS)-sugar mixture on glycemic index (GI) and blood glucose in human subjects. METHODS: Randomized double-blind cross-over studies were conducted to examine the effect of sucrose with 14% xyloologosaccharide powder (Xylo 14) and sucrose with 20% xylooligosaccharide powder (Xylo 20) on GI and postprandial glucose response at 15, 30, 45, 60, 90, and 120 min. RESULTS: GIs of Xylo 14 and Xylo 20 were 60.0 +/- 23.5 classified within medium GI range, and 54.3 +/- 17.7 within low GI range, respectively. Xylo 14 and Xylo 20 showed significantly lower area under the glucose curve (AUC) for 0-15 min (p = 0.0113), 0-30 min (p = 0.0004), 0-45 min (p < 0.0001), 0-60 min (p < 0.0001), 0-90 min (p < 0.0001), and 0-120 min (p = 0.0001). In particular, compared with glucose, the blood glucose levels of Xylo 14 and Xylo 20 were significantly lower at every time point between 15 and 120 min. CONCLUSION: The results of this study suggested that Xylo 14 and Xylo 20 had an acute suppressive effect on GI and the postprandial glucose surge.

Effect of probiotics and xylo-oligosaccharide on performance,digestive enzyme activities,blood index and intestinal microflora of early weaned piglets / 中国兽医学报

To evaluate the effects of supplemental probiotics and xylo-oligosaccharide on performance,digestive enzyme activities,blood index and intestinal microflora.Two hundred and forty crossbred early weaned PIC piglets with an average initial weight of (6.83 + 0.9) kg,weaned at (21 ± 2) d of age,were divided into four groups.Control Ⅰ (positive diet,with no probiotics and xylo-oligosaccharide but more fish meal,whey powder and little soybean meal),Control Ⅱ (negative diet,with no probiotics and xylo-oligosaccharide but less fish meal,whey powder and more soybean meal),Negative diet + 0.035 % probiotics,negative diet + 0.002% xylo-oligosaccharide.The results of theses studies suggested that whey powder and fish meal from 5.50% to 2.50%,soybean meal from 22.50% to 26.50% could result in decreasing of alimentary canal enzyme activity,blood sugar,total serum protein and the quantities of Bacillus in appendix(P<0.05),and raising of serum urea nitrogen,the quantities of Escherichia coli in appendix,diarrhea indexes and Feed/Gain(P<0.05).Addition of probiotics and xylo-oligosaccharide could significantly improve the activities of alimentary canal protein,lipase and amylase(P<0.05),decrease Feed/Gain and the levels of blood sugar and decrease the levels of serum urea nitrogen and improve protein equilibrium in blood and energy metabolism.The quantities of bacillus were improved,Escherichia coli were decreased in appendix(P<0.05).Diarrhea indexes were decreased(P<0.05).Whether adding probiotics and xylo-oligosaecharide or not could not affect ADG and ADFI (P>0.05).Addition of probiotics and xylo-oligosaccharide could improve digestive function,beneficial microbial population of post-alimentary canal,Feed/Gain and prevent the diarrhea of piglets.

Effects of Xylooligosaccharide Intake on Fecal Bifidobacteria,Lactic acid and Lipid Metabolism in Korean Young Women

This study investigated the effects of xylooligosaccharide on feces bifidobacteria proliferation, lactic acid concen-tration and lipid metabolism in healthy woman. Fourteen volunteers were randomly assigned to 2 groups : 1.4 g/day xylooligosaccharide intake group, 2.8 g/day xylooligosaccharide intake group. The duration of the study was 28 days. The amount of feces and excretion time were not affected by xylooligosaccharide intake. The color of feces changed to yellow brown, and hardness of stool and effort to evacuation were reduced by xylooligosaccharide intake. Xylooligo-saccharide intake reduced the fecal pH significantly after 14 days in 2.8 g/day intake group (p <0.05 ). The number of fecal bifidobacteria were significantly increased after 28 days in 1.4 g/day intake group (p <0.05 ), and in 2.8 g/day in-take group, the number of fecal bifidobacteria significantly increased after 14 days (p <0.05 ). Water contents of feces were not affected by xyloolgosacchride intake. The fecal triglyceride and cholesterol concentrations were increased in 2.8 g/day intake group (p <0.05 ), and in 1.4 g/day intake group, fecal cholesterol concentration only was increased (p <0.05 ). The fecal lactic acid concentration was significantly increased in 2.8 g/day intake group (p <0.05 ). Serum trigly-ceride, cholesterol and glucose concentration were significantly decreased in 2.8 g/day intake group (p <0.05 ). In conclusion, xylooligosaccharide dietary supplementation may be beneficial to gastrointestinal health and lipid metabolism, and 2.8 g/day intake was more effective than 1.4 g/day intake.