不同表面活性剂对体外培养瘤胃微生物几种纤维降解酶活力和小麦秸秆降解的影响

摘要

Effects of different inclusion levels (0.1% or 0.2% in final concentration)of anionic surfactant (calcium stearate),zwitterionic surfactants (soy lecithin and betaine)and non-ionic surfactants (Tween80, PEG20000 and Span80)on fiber degrading enzyme activities of ruminal microorganisms and substrate de-gradability after 24h in vitro fermentation were investigated.The activity of xylanase were increased by 35.4%,34.6% and 26.8%(P <0.05 )after increase of 0.1% PEG20000,betaine and soy lecithin,respec-tively.In addition,after addition of 0.1% Span80,betaine,soy lecithin and calcium stearate,endo-β-1,4- glu-canase activity were improved by 27.1%,78.9%,90.3% and 37.4% (P <0.05),respectively.As a result, DM degradability of wheat straw increased by 29.6% and 39.9% (P <0.05 )and NDF degradability in-creased by 54.6% and 91.8% (P <0.05)after increase of betaine and soy lecithin.When soy lecithin and PEG20000 supplement level were increased by 0.2%,the xylanase increased by 48.9% and 46.0% (P <0.05),and the DM degradability of wheat straw increased by 29.9% and 30.6% (P <0.05),and NDF de-gradability increased by 42.3% and 69.1% (P <0.05).The results suggest that the action mechanisms of soybean lecithin ,PEG 2 0 0 0 0 and betaine improved xylanase and endo-β-1 ,4-glucanase activity ,and thus improving the degradation of DM and NDF of wheat straw.In general,the order of these surfactants in reg-ulating ruminal fermentation is as follows:soy lecithin>PEG20000>betaine>Tween 80 >calcium stea-rate>Span80.%研究3类表面活性剂：非离子表面活性剂(PEG20000,Span80和吐温80)、阴离子表面活性剂(硬脂酸钙)和两性离子表面活性剂(甜菜碱和大豆磷脂)对瘤胃微生物体外发酵和纤维素降解酶活力的影响。结果表明,添加0.1％的 PEG20000、甜菜碱或大豆磷脂后,木聚糖酶活力分别提高35.4％(P ＜0.05),34.6％(P ＜0.05),26.8％(P ＜0.05)；Span80、甜菜碱、大豆磷脂和硬脂酸钙使内切β-1,4-葡聚糖酶活力分别提高27.1％(P ＜0.05),78.9％(P ＜0.05),90.3％(P ＜0.05),37.4％(P ＜0.05)。甜菜碱和大豆磷脂使小麦秸秆干物质降解率提高29.6％(P ＜0.05)和39.9％(P ＜0.05),中性洗涤纤维降解率分别增加54.6％(P ＜0.05)和91.8％(P ＜0.05)。当大豆磷脂和PEG20000添加水平增加到0.2％时,木聚糖酶增加48.9％(P ＜0.05)和46.0％(P ＜0.05)。添加0.2％的PEG20000和大豆磷脂后干物质降解率提高29.9％(P ＜0.05)和30.6％(P ＜0.05),中性洗涤纤维降解率提高42.3％(P ＜0.05)和69.1％(P ＜0.05)。在体外条件下,大豆磷脂、PEG20000和甜菜碱通过提高瘤胃微生物木聚糖酶、内切β-1,4-葡聚糖酶活力增加小麦秸秆干物质和中性洗涤纤维降解率。综合来看,表面活性剂对瘤胃发酵影响程度的顺序依次为：大豆磷脂＞PEG20000＞甜菜碱＞吐温80＞硬脂酸钙＞Span80。