Effects of lactic acid bacteria with bacteriocinogenic potential on the fermentation profile and chemical composition of alfalfa silage in tropical conditions
Effects of lactic acid bacteria with bacteriocinogenic potential on the fermentation profile and chemical composition of alfalfa silage in tropical conditions
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热带条件下产细菌素乳酸菌对苜蓿青贮发酵特性和化学成分的影响
DOI：
10.3168/jds.2015-9792
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发表时间：
2016-03-01
影响因子：
3.5
通讯作者：
Santos, S. A.
中科院分区：
文献类型：
--
作者：
Silva, V. P.;Pereira, O. G.;Santos, S. A.
在热带条件下，研究了不同发酵期（T）接种微生物菌剂（MI）处理苜蓿青贮的发酵特性、化学成分和微生物种群。在随机设计中使用4 x 6析因排列，重复3次。用（1）不处理（CTRL）、（2）商业接种剂（CIN）、（3）乳酸片球菌（菌株10.6，S1）和（4）戊糖片球菌（菌株6.16，S2）处理新鲜苜蓿。使用10（6）cfu/g新鲜草料的接种剂施用率。发酵周期分别为1、3、7、14、28和56 d。紫花苜蓿在开花初期播种后82天收获，切成1.5厘米的颗粒，装在25 x 35厘米的真空密封塑料袋中。青贮前苜蓿中乳酸菌、肠杆菌、霉菌和酵母菌的数量分别为5.42、5.58、4.82和4.8logcfu/g。青贮饲料的化学成分仅在56 d时进行评价。除了乳酸和丙酸的浓度外，所有参数都受到MI x T相互作用的影响。从第1天到第28天，添加S1或S2的苜蓿青贮的pH值均低于对照。然而，接种物在56 d后产生类似的pH，并且这些值低于对照。在青贮7 d和14 d时，S1和S2处理的青贮料中乳酸含量最高。在发酵3 d和28 d时，S1和S2处理的青贮饲料中乙酸浓度低于对照组和CIN组。MI或MI x T相互作用对微生物种群没有影响。然而，肠杆菌的数量在发酵期间下降，直到14天，并在此时间点后略有增加。在青贮56 d时，MI对苜蓿青贮饲料的化学成分没有影响。菌株P. pentosaceus 6.16通过更快地降低pH和增加乳酸浓度在控制发酵过程中是最有效的，这表明其作为青贮接种剂的潜在用途。
The fermentation profile, chemical composition, and microbial populations of alfalfa silages treated with microbial inoculants (MI) at different fermentation periods (T) were evaluated in tropical conditions. A 4 x 6 factorial arrangement was used in a randomized design with 3 replicates. Fresh alfalfa was treated with (1) no treatment (CTRL), (2) commercial inoculant (CIN), (3) Pediococcus acidilactici (strain 10.6, S1), and (4) Pediococcus pentosaceus (strain 6.16, S2). An inoculant application rate of 10(6) cfu/g of fresh forage was used. The fermentation periods were 1, 3, 7, 14, 28, and 56 d. Alfalfa was harvested 82 d after sowing at the early flowering stage, chopped into 1.5-cm particle size, and ensiled in 25 x 35 cm vacuum-sealed plastic bags. The numbers of lactic acid bacteria, enterobacteria, mold, and yeast in alfalfa before ensiling were 5.42, 5.58, 4.82, and 4.8 log cfu/g, respectively. Silage chemical composition was evaluated only at 56 d. All parameters were affected by the interaction MI x T, except the concentrations of lactic and propionic acids. Alfalfa silage treated with S1 or S2 had lower pH values than CTRL from the first day until 28 d. However, the inoculants resulted in similar pH after 56 d, and these values were lower than the CTRL. The highest concentration of lactic acid was observed in the silage treated with S1 and S2 at 7 and 14 d of ensiling. The concentration of acetic acid was lower in the silages treated with S1 and S2 than the CTRL and CIN at 3 and 28 d of fermentation. There was no effect of MI or MI x T interaction on the microbial populations. However, the number of enterobacteria decreased over the fermentation period until 14 d and increased slightly after this time point. The chemical composition of alfalfa silage was not affected by MI at 56 d of ensiling. The strain P. pentosaceus 6.16 was the most efficient in dominating the fermentation process by decreasing the pH more quickly and increasing the concentration of lactic acid, suggesting its potential use as a silage inoculant.