[Objective] Study on antibacterial activity and stability of the ethanol extracts from Allium mongolicum Regel.[Method] Taking Allium mongolicum Regel.(AMR)as experimental material,the antibacterial and stability test...[Objective] Study on antibacterial activity and stability of the ethanol extracts from Allium mongolicum Regel.[Method] Taking Allium mongolicum Regel.(AMR)as experimental material,the antibacterial and stability test,antibacterial capacity and antibacterial activity substance stability of extracts were studied.[Result] Size order of antibacterial effect of extracts on these 5 strains tended to be:Saccharomyces cerevisiae > Penicillium sp.> Aspergillusniger> Staphylococcusaureus> Escherichia coli;under neutral or slight alkaline conditions,optimum antibacterial effect presented best;and UV light irradiation basically had no influence on tested strains.[Conclusion] Antibacterial effect of ethanol extract shows great difference among these strains,and antibacterial activity substance is of good heat and UV light stability.展开更多
本试验旨在通过体外发酵法研究不同水平沙葱粉对牦牛瘤胃体外发酵参数、营养物质降解率和微生物区系的影响。采用体外发酵法,在发酵罐中分别加入1 g全混合日粮(TMR,发酵底物)(YZA组)、1 g TMR+1.2%沙葱粉(YLA组)、1 g TMR+2.4%沙葱粉(YM...本试验旨在通过体外发酵法研究不同水平沙葱粉对牦牛瘤胃体外发酵参数、营养物质降解率和微生物区系的影响。采用体外发酵法,在发酵罐中分别加入1 g全混合日粮(TMR,发酵底物)(YZA组)、1 g TMR+1.2%沙葱粉(YLA组)、1 g TMR+2.4%沙葱粉(YMA组)、1 g TMR+3.6%沙葱粉(YHA组),在发酵时间分别到达4、8、16、24、48和72 h时采集发酵液及底物残渣,测定发酵参数、营养物质降解率及微生物区系。结果表明:1)与YZA组相比,发酵从16 h开始,YMA组和YHA组氨态氮(NH3-N)含量均极显著降低(P<0.01),发酵16和72 h时,YMA组和YHA组菌体蛋白(MCP)含量极显著升高(P<0.01);发酵4和16 h时,YLA组和YMA组pH均显著降低(P<0.05),48 h时YMA组pH显著降低(P<0.05),72 h时YMA组pH极显著降低(P<0.01);除72 h外,其余各时间点YLA组和YMA组总挥发性脂肪酸(TVFA)和乙酸含量显著(P<0.05)或极显著(P<0.01)升高;各发酵时间点YLA组和YMA组丙酸含量显著(P<0.05)或极显著(P<0.01)升高。2)与YZA组相比,发酵时间4、24、72 h时,YMA组干物质降解率(DMD)显著升高(P<0.05);发酵4、24、48和72 h时,YMA组和YHA组中性洗涤纤维降解率(NDFD)显著(P<0.05)或极显著(P<0.01)升高;各发酵时间点,YLA组和YMA组酸性洗涤纤维降解率(ADFD)显著(P<0.05)或极显著(P<0.01)升高。3)不同添加水平沙葱粉并未改变瘤胃主要微生物类群的占比,但可增加属水平普雷沃氏菌科UCG-001(YMA组)和F082(YMA组和YHA组)等有益微生物的相对丰度,提高底物营养物质降解率。4)毛螺菌科UCG-009相对丰度与丙酸含量呈极显著正相关(r=0.982;P<0.01),与DMD呈极显著负相关(r=-0.990;P<0.01),土圈菌DEV114相对丰度与异戊酸含量呈极显著正相关(r=0.998;P<0.01),不动杆菌属相对丰度与丙酸含量呈极显著负相关(r=-0.994;P<0.01),与DMD呈极显著正相关(r=0.984;P<0.01)。综上所述,在本试验条件下,饲粮中添加2.4%沙葱粉能改善牦牛瘤胃体外发酵参数和营养物质降解率,促进有益菌的增殖,且部分参数变化呈现剂量依赖效应。展开更多
文摘[Objective] Study on antibacterial activity and stability of the ethanol extracts from Allium mongolicum Regel.[Method] Taking Allium mongolicum Regel.(AMR)as experimental material,the antibacterial and stability test,antibacterial capacity and antibacterial activity substance stability of extracts were studied.[Result] Size order of antibacterial effect of extracts on these 5 strains tended to be:Saccharomyces cerevisiae > Penicillium sp.> Aspergillusniger> Staphylococcusaureus> Escherichia coli;under neutral or slight alkaline conditions,optimum antibacterial effect presented best;and UV light irradiation basically had no influence on tested strains.[Conclusion] Antibacterial effect of ethanol extract shows great difference among these strains,and antibacterial activity substance is of good heat and UV light stability.