多山梨醇酯20对棉花秸秆体外发酵的影响

Effect of Polysorbate 20 on the In Vitro Ruminal Fermentation of Cotton-straw

采用体外培养技术,研究不同添加水平的多山梨醇酯20对棉花秸秆体外发酵的影响。结果表明:多山梨醇酯20能显著提高棉花秸秆体外发酵24 h的累积产气量和发酵速度。与对照组相比,0.1%、0.2%、0.4%和0.8%的多山梨醇酯20使24 h累积产气量分别提高27.95%(P<0.01)、32.30%(P<0.01)、43.48%(P<0.01)和19.88%(P<0.01)。多山梨醇酯20使棉花秸秆中的干物质、有机物、纤维素和半纤维素24h降解率提高,其中0.2%组的干物质、有机物和半纤维素的24 h降解率为各组最高,分别比对照组提高12.71%(P<0.05)、11.81%(P>0.05)和115.96%(P<0.01);纤维素的24h降解率以0.4%最高,较0%提高33.67%(P<0.01)。添加多山梨醇酯20后,使pH和还原糖显著下降。除0.2%组外,总挥发性脂肪酸显著高于对照组。羧甲基纤维素酶(CMCase)活性有增加的趋势,0.8%组的CMCase活性较0%组高114.05%(P<0.01)。低浓度多山梨醇酯20有提高微生物(MCP)的趋势,但随着多山梨醇酯20添加浓度的增加,MCP逐渐下降,培养上清中的氨态氮浓度呈现线性增加。在体外厌氧培养条件下,多山梨醇酯20明显促进棉花秸秆在混合绵羊瘤胃液中的降解。

The suffactant polysorbate 20 was evaluated for its effects on the in vitro fermentation of cotton - straw by mixed sheep ruminal microorganisms. The results showed that polysorbate 20 raised 24h accumulative gas production and fermentation rate. Compared with the control group, the 24h cumulative gas production of 0.1%, 0.2 %, 0.4 % and 0. 8% group increased by 27.95%（P〈0.01）,32.30% （P〈0.01）,43.48% （P 〈 0.01） and 19.88% （P〈0.01） respectively. The degradability of DM, OM and hemicellulose in 0.2 % group and cellulose in 0.4 % group were improved by 12.71% （P〈0.05）, 11.81% （P〉0.05）, 115.96% （P〈0.01） and 33.67% （P〈0.01） respectively. At the end of 24h anaerobic culture, the pH and reducing sugar decreased significantly. The TVFA increased dramatically in all treated groups except for the 0.2% group. After the addition of polysorbate 20, the CMCase activity of the 0.8% group increased by 114.05% （P〈0.01） compared with that of the control group. The MCP tended to increase in groups of lower concentration, while decrease in groups of higher concentration. With the increase in the concentration, the NH3 - N in culture supernatant increased linearly. In present research, polysorbate 20 could greatly stimulate the degradation.of cotton - straw in in vitro anaerobic fermentation.