Novel lactic acid bacterium and method for preparing silage or fermented feed by using the same

Abstract

An object of the present invention is to provide a lactic acid bacterium, in a silage or fermented feed material on which any sufficient fermentation quality-improving effect cannot be established by conventional lactic acid bacteria because of a low saccharide content thereof and therefore which undergoes butyric acid fermentation, the lactic acid bacterium inhibiting the butyric acid fermentation and thus enabling stable preparation of a silage or fermented feed having good qualities. A lactic acid bacterium capable of producing 40 IU or greater, per mL of supernatant, of nisin in a grass extract medium having a total content of monosaccharides and disaccharides of 0.1-0.4 mass%; a microbial preparation for preparing silages, the preparation containing the aforethe lactic acid bacterium; and a method for preparing a silage or fermented feed using the preparation.

Description

Technical field [0001] The present invention relates to lactic acid bacteria capable of inhibiting butyric acid fermentation, a microbial preparation containing the same, and a method for preparing silage or fermented feed using the preparation. Background technique [0002] The silage obtained by lactic acid fermentation under anaerobic conditions for the staple food of livestock, such as forage grass and fodder crops, is a necessary feed in the dairy industry. The preparation of high-quality silage is a very important technology for dairy farmers. At this time, the problem called poor fermentation frequently occurs. This is because the growth of butyric acid bacteria in silage is more advantageous than that of lactic acid bacteria. As a result, the content of butyric acid in the silage becomes higher. Silage with a higher concentration of butyric acid not only causes a decrease in the hobby and feed intake of cattle, but also becomes a problem related to diseases such as ketosi...

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Problems solved by technology

Therefore, lactic acid bacteria producing high concentrations of nisin in a synthetic medium and nisin producing in a fermented barley extract medium have also been reported (Patent Document 1, Non-Patent Document 6), but no synthetic Existing literature on the production of high concentrations of nisin in culture medium or fermented barley extract medium, and in silage materials with different nutrient sources

[0007] In addition, in the case of silage as an object, a silage preparation method in which bacteriocin-producing Lactococcus lactis RO50 strain is added to silage material grass has been reported (Patent Document 2), but it has also been reported that sufficient silage is not obtained. In the case of improving the fermentation quality, the effect is not stable, and it is completely unclear whether bacteriocin is produced in the silage (Non-Patent Documents 7 and 8)

In addition, in Patent Document 3, there is also a report on a method for preparing silage by adding nisin-producing lactic acid bacteria and nisin-resistant lactic acid bacteria. Although 200 IU / g of nisin activity was detected in the silage, but Since there is no change in the fermentation quality such as pH, organic acid content, and ammoniacal nitrogen concentration relative to total nitrogen compared with other lactic acid bacteria that do not produce nisin, good fermentation can be obtained even with common lactic acid bacteria The results of the sugar content (5.0% or more in the dry product, 1.0% or more in the raw material) are not yet clear about the effect of this lactic acid bacteria under the strict conditions of low sugar content

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