PCR-DGGE analysis of silage microorganisms and its application to food quality control

在日本，高水分副产品作为全混合日粮青贮饲料与干饲料一起储存已成为一种常见的做法。这可以将产生污水的风险降到最低，并可以省去投料前的混合时间。如果在筒仓中发酵改变了TMR青贮料的气味和味道，那么令人不快的副产品可能会被加入TMR青贮料中。TMR青贮料的一个有趣的特性是在空气中的高度稳定性。即使在夏天也不会发生加热，而非敏化的TMR混合物可能会很快变质。传统的标准不能很好地解释稳定性，因为TMR青贮可以保持不加热，即使有大量的酵母菌和大量的底物(糖和乳酸)用于好氧微生物的生长。用聚合酶链式反应-变性梯度凝胶电泳法对影响抗腐性的因素进行了研究，得到了一些有趣的结果，如…。再低一点。当湿啤酒糟和豆腐渣单独储存或与其他饲料混合作为TMR青贮料时，变质并不只发生在TMR青贮料中。在没有厌氧发酵的情况下，TMR混合物也很容易变质。布氏乳杆菌是一种能够提高有氧稳定性的异源发酵乳酸菌，在青贮料中没有发现，但在含湿啤酒糟的TMR青贮料中已出现。尽管添加豆腐渣的TMR青贮料的有氧稳定性同样很高，但无论青贮期如何，都没有检测到布氏乳杆菌。卫氏杆菌(Weisella sp.)在两种稳定的TMR青贮料中都发现了短乳杆菌。单独储藏的不稳定副产品青贮料中不含这两种乳酸菌。我们可以从后续的实验中分离出布氏乳杆菌、短乳杆菌和杂乱魏氏杆菌，因此现在正计划进行接种实验，以确定这些细菌混合物是否真的能提高青贮料的有氧稳定性。较少

It has become a common practice in Japan that high-moisture by-products are stored with dry feeds as an total mixed ration silage. This may minimize the risk of effluent production and can omit the time for mixing prior to feeding. Unpalatable by-products could be incorporated into a TMR silage, if their odors and flavors are altered through the fermentation in a silo. An interesting property of the TMR silage is high stability on exposure to air. Heating would not occur even in summer, whereas non-ensiled TMR mixture may deteriorate quite rapidly. Conventional criteria do not account well for the stability, because the TMR silage can remain unheated even with a large number of yeasts and a substantial level of substrates (sugars and lactic acid) for the growth of aerobic microorganisms. We have investigated the factors involved in resistance to deterioration by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE), and some interesting results are obtained as fo … More llows.1. When wet brewers grains and soybean-curd refuse were stored alone or in combination with other feeds as a TMR silage, deterioration did not occur only in TMR silages. Without anaerobic fermentation, TMR mixture also spoiled quite easily.2. Lactobacillus buchneri, a hetero-fermentative lactic acid bacteria which is capable of enhancing aerobic stability, was not found in the silage material, but appeared from the early ensiling period in TMR silage containing wet brewers grains. Although aerobic stability was similarly high in TMR silage containing soybean-curd refuse, L. buchneri was not detected regardless of ensiling period.3. Weisella sp. and Lactobacillus brevis was found in both the stable TMR silages. Unstable by-products silage stored alone did not contain these two lactic acid bacteria.4. We could isolate those L. buchneri, L. brevis and Weisella confusa from the following experiment, hence now are planning to inoculation experiment to determine if these bacterial mixture can actually improve the aerobic stability of silage. Less