不同来源木聚糖酶及其组合对木聚糖水解产物组成、细菌增殖与大肠杆菌黏附性的影响

本试验旨在研究不同来源木聚糖酶及其组合对木聚糖的水解效果,并研究不同木聚糖水解产物对细菌增殖及大肠杆菌对肠道上皮细胞黏附性的影响。试验用木聚糖酶A和木聚糖酶B分别来源于毕赤酵母和米曲霉。采用木聚糖酶A、木聚糖酶B、组合酶1(木聚糖酶A∶木聚糖酶B=3∶7)、组合酶2(木聚糖酶A∶木聚糖酶B=1∶1)、组合酶3(木聚糖酶A∶木聚糖酶B=7∶3)分别水解木聚糖,然后测定木聚糖水解产物对大肠杆菌、枯草芽孢杆菌和乳酸杆菌增殖和大肠杆菌对肠道上皮细胞黏附性的影响。结果表明:1)2种木聚糖酶有一定的组合效应,木聚糖酶A、木聚糖酶B、组合酶1、组合酶2、组合酶3组木二糖和木三糖的总含量分别为95.70%、86.79%、93.11%、94.55%和87.55%,其中木聚糖酶A组木二糖含量最高,组合酶2组木三糖含量最高。2)培养20 h时,5种木聚糖水解产物对大肠杆菌的增殖(以菌液吸光度值表示)没有产生显著影响(P0.05);培养20和30 h时,5种木聚糖水解产物显著促进枯草芽孢杆菌的增殖(P0.05);培养13和17 h时,5种木聚糖水解产物显著促进乳酸杆菌的增殖(P0.05)。3)5种木聚糖水解产物均可以显著降低大肠杆菌对肠道上皮细胞的黏附率(P0.05)。由此可见,通过不同来源木聚糖酶及其组合水解木聚糖,可以产生以木二糖和木三糖为主要组分的水解产物,从而起到促进枯草芽孢杆菌和乳酸杆菌增殖、减少大肠杆菌对肠道上皮细胞黏附的作用。

Effects of Different Sources of Xylanase and Their Combinations on Xylan Hydrolysate Composition,Bacteria Proliferation and Escherichia coli Adhesion

This experiment was conducted to study the hydrolysis effect of different sources of xylanase and their combinations on xylan,and then research the effects of xylan hydrolysate on bacteria proliferation and adhesion of Escherichia coli to intestinal epithelial cells (IEC).Xylanases from Pichia pastoris and Aspergillus oryzae were named xylanase A and xylanase B,respectively.The xylanase A,xylanase B,combined enzyme 1 (xylanase A:xylanase B =3:7),combined enzyme 2 (xylanase A:xylanase B =1∶1),combined enzyme 3 (xylanase A ∶xylanase B =7∶3) were used to hydrolyze xylan,respectively.The effects of xylan hydrolysate on Escherichia coli,Bacillus subtilis and Lactobacilli proliferation and the adhesion of Escherichia coli to IEC were measured.The results showed as follows:1) some combined effects of two kinds of xylanase were observed.The total content of xylobiose and xylotriose in xylanase A,xylanase B,combined enzyme 1,combined enzyme 2 and combined enzyme 3 groups were 95.70％,86.79％,93.11％,94.55％ and 87.55％,respectively.The content of xylobiose in xylanse A group was the highest,while the highest content of xylotriose in combined enzyme 2 group.2)Five kinds of xylan hydrolysate had no significant effect on the proliferation expressed in optical density (OD) value] of Escherichia coli cultured at 20 hours (P＞0.05),but significantly improved the proliferation of Bacillus subtilis cultured at 24 and 30 hours (P＜0.05),and significantly improved the proliferation of Lactobacilli cultured at 13 and 17 hours (P＜0.05).3) Five kinds of xylan hydrolysate could significantly reduced the adhesion rate of Escherichia coli to IEC(P＜0.05).It is concluded that xylan hydrolyzed by difference sources of xylanase and their combinations can produce xylan hydrolysate with xylobiose and xylotriose as main components,which can promote Bacillus subtilis and Lactobacillus proliferation and reduce the adhesion of Escherichia coli to IEC.