乳酸菌复合系SFC-2发酵液对秸秆饲料的抑菌作用

Antibacterial activity of lactic acid bacteria community SFC-2 on straw feed

为揭示乳酸菌发酵液直接吸附生产秸秆饲料的新工艺中,发酵液对秸秆饲料的保鲜作用及其机制,以玉米秸秆为原料,以乳酸菌复合系SFC-2发酵液为处理剂,设不同添加量(0、75、150、375mL/kg),研究吸附后24h内秸秆的理化性质、微生物群动态变化及有氧稳定性。结果表明添加SFC-2发酵液后:1)提高秸秆的营养价值和风味,添加量越大,效果越明显;2)添加75mL/kg时,秸秆的有氧稳定性提高,其余处理有氧稳定性降低;3)添加发酵液可以减少饲料有氧放置过程中粗蛋白的损失;4)变性梯度凝胶电泳(Denaturing gel gradient electrophoresis,DGGE)图谱分析表明,添加发酵液的处理中主导菌群是SFC-2中的Lactobacillus fermentum和L.plantrum,未发现对照中的杂菌条带。由此可见,添加适量SFC-2发酵液可通过有效抑制杂菌的繁殖,提高饲料的有氧稳定性等来实现保鲜作用。

A new straw feed producing process by applying lactic acid bacteria culture on the straw feed was proposed.In order to reveal the preservation effect of the bacteria culture on straw feed and mechanism involved,in this study,corn stalk was used as raw material,culture broth of lactic acid bacteria community SFC-2was used as additive in different ratios（0,75,150,375mL/kg）.By analyzing the physicochemical properties of straw and dynamic change of microorganisms in constant 24 hours after exposed to air,the results were as follows：1）After adding lactic acid bacteria culture broth,smell and contents of water soluble carbohydrate（WSC）and crude protein（CP）were all improved,and these traits showed a positive correlation with the content of SFC-2fermentation broth;2）The aerobic stability of the straw feed was improved when 75mL/kg was given,and decreased in other treatments;3）Loss of crude protein was reduced when SFC-2fermentation broth was given;4）The band patterns of denaturing gradient gel electrophoresis revealed that strains of SFC-2were the dominant species in the inoculated feedstuff,and many bands which appeared in the control were not detected in the inoculated feedstuff.In conclusion,by adding SFC-2culture broth,some bacteria except SFC-2were significantly restrained,and the aerobic stability of straw feed was improved.