JPH07108215B2 - New lactic acid bacteria - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel lactic acid bacterium belonging to the genus Lactobacillus and mainly used for preparing silage, fermented sausage, pickles and the like.

[Conventional technology]

Since the preparation of silage and the like described above is common in that it is required to secure a large amount of lactic acid accumulation from the early stage of fermentation, the following description will be made taking silage preparation as an example. Nara silage is produced mainly by slaughtering grass and storing it in silos to ferment it in an anaerobic state.

[Problems to be Solved by the Invention]

However, immediately after cutting silage raw materials such as grass and the like, they are exposed to the air and thus have an aerobic atmosphere, so that a predetermined anaerobic fermentation cannot occur from the beginning. Therefore, in order to use it as livestock feed, the cut feed itself must be respired and oxygen between the stacked raw materials must be fully consumed to reach an anaerobic atmosphere. Then, it took a considerable time for the anaerobic fermentation to proceed.
In other words, the anaerobic bacteria including lactic acid bacteria generally have a significantly lower growth ability in the aerobic condition than in the anaerobic condition. Therefore, a large number of aerobic bacteria grow and reach the anaerobic condition before the silage raw material reaches the anaerobic atmosphere. The growth of lactic acid bacteria was sometimes suppressed as a result.

Also, even if the anaerobic atmosphere is reached, if the viable count of lactic acid bacteria does not reach a certain number or more, spoilage bacteria such as butyric acid bacteria that emit an unpleasant smell of livestock may grow before lactic acid bacteria, and always It has not been possible to achieve good silage preparation by good anaerobic fermentation.

This situation is the same when preparing fermented sausages and pickles.

Therefore, the present invention eliminates the problems of the above-mentioned conventional techniques, the growth rate of the bacteria is fast, and immediately after the start of fermentation for silage raw materials such as grass, it quickly grows and has high nutritional value. An object of the present invention is to provide a novel lactic acid bacterium that surely promotes lactic acid fermentation that gives the taste that is preferred by lactic acid bacteria.

[Means for Solving the Problems]

To achieve the above object, the novel lactic acid bacterium according to the present invention is characterized in that it belongs to the genus Lactobacillus and has a lactic acid fermentation ability in both aerobic and anaerobic atmospheres. (1st Microbiology Research Institute
No. 0474).

[Action / effect]

The present inventors have made great efforts to discover lactic acid bacteria that actively carry out lactic acid fermentation from the initial stage of the preparation of silage and the like. In addition, we succeeded in finding a bacterium that rapidly grows in anaerobic atmosphere and causes rapid and large accumulation of lactic acid and accompanying pH decrease.

The lactic acid bacterium and the Lactobacillus KB-141 strain according to the present invention have the following mycological properties.

Culture medium LCM (Lactobacillus casodium) medium pH: 6.8, which shows good growth when cultured at 37 ° C for 24 hours.

Form Bacillus spores None Gram stain Positive Physiological properties Lactic acid fermentation Homo-type catalase None Growth temperature 30-35 ° C Growth temperature 15-40 ° C Sugar assimilation (For this, a strain preserved in the Department of Applied Bacteriology, Hokkaido University) The result of comparison with a certain Lactobacillus plantarum standard bacterium is shown in Table 1.) Regarding the assimilation of sugars, BTB was added to a basic medium having the following composition, sterilized at 121 ° C for 20 minutes, and each sugar was added to 2% after cooling, and then a suspension of lactic acid bacteria was added. Was inoculated drop by drop and cultured at 30 ° C. for examination. And culture 7
It was judged that there was assimilation in the medium in which the color of the medium changed from green to yellow as a result of proliferation after a day.

Basic medium Polypeptone 0.5% Yeast extract 0.5% Dipotassium phosphate 0.5% From the above results, it is clear that the lactic acid bacterium of the present invention belongs to the genus Lactobacillus, and Lactobacillus plantarum AHU-1526 (hereinafter, L. plantarum and Abbreviated.)
It is recognized as a fungus species of. However, L. plantarum means sorbose, trehalose, starch, L.
-Arabinose, ribose, rhamnose have different assimilation abilities, and as described in detail in Examples, rapidly proliferate in both aerobic and anaerobic atmospheres in the early stage of culture, and the amount of lactic acid accumulated. There are significant differences in that there is a large amount of water and the concomitant decrease in pH value.

Considering these facts, it was confirmed that this strain was a novel lactic acid bacterium belonging to the genus Lactobacillus, and was named Lactobacillus KB-141 strain.

Since this KB-141 strain grows rapidly even under aerobic and anaerobic conditions, as described below, a large number of KB-141
In the initial stage of preparation in which 141 strains are mixed with raw materials such as grass, bacteria such as spoilage bacteria can be overwhelmed by the viable cell count, and the growth of other bacteria can be suppressed. Therefore, it is possible to prevent the deterioration of the taste such as silage due to the growth of anaerobic butyric acid bacteria.
Moreover, the amount and rate of lactic acid accumulation are equal to or higher than those of the standard bacterium L. plantarum, and the lactic acid fermentation capacity is sufficient.

Therefore, according to the present invention, it is possible to provide a silage or the like that is stable and has an excellent quality and is hardly affected by other bacteria.

This strain, Lactobacillus KB-141, is
No. 0474 has been deposited at the Institute of Microbial Technology of the Agency of Industrial Science and Technology.

〔Example〕

Below, the experimental results relating to the growth rate and lactic acid production ability of this strain are shown using the silage adjusting ability as an index.

[Experimental Example 1] Lactic acid accumulation of sugars that were assimilated (%)
The amount of lactic acid accumulated was further measured for sugars that were assimilated in both KB-141 and the standard strain L. plantarum in Table 1 above. Sugar was added to the above basic medium at 30 ° C. so as to be 2.0%, and the mixture was cultured, and the amount of lactic acid accumulated after 48 hours and 96 hours of culture was measured. The results are shown in Table 2.

From the above results, KB-141 of the present invention is L- which is a standard strain.
It was confirmed that sugar assimilation capacity was higher than that of plantarum.

[Experimental Example 2] Comparison of growth properties Glucose 2.0% and calcium carbonate 0.5% were added to the basal medium.
The number of viable cells was determined by the usual dilution plate culture method using a medium containing 1% and agar. The results are shown in Fig. 1 (a),
Shown in (b) and (c).

From this result, the initial growth rate of KB-141 of the present invention is particularly higher than that of the standard strain L. plantarum, and the stable state after the pH decrease even in the viable cell count under the conditions of pH 4.0 or less at which the growth of lactic acid bacteria is suppressed. It was confirmed that the standard strain was exceeded at 20 ° C, which is the usual condition in.

[Experimental Example 3] Comparison of Lactic Acid Accumulation (%) and pH 2.0% glucose was added to the basic medium, KB-141 and L. plantarum were inoculated, respectively, and 20 ° C., 30 ° C. and 37 ° C. Lactic acid accumulation was measured in pH. The amount of accumulated lactic acid was measured by the titration method and calculated by the following formula.

Lactic acid amount = N / 10 drop constant of sodium hydroxide x f x 0.009 x 100 / sample amount The measurement results are shown in Table 3 and the pH at 20 °, 30 ° and 37 ° C.
Figure 2 (a), (b), and (c) show the changes with time in the amount of lactic acid and lactic acid.

From these results, it was confirmed that KB-141 of the present invention rapidly accumulates lactic acid and lowers the pH as compared with the standard strain L. plantarum until the pH is around 4 at which the growth of lactic acid bacteria themselves is inhibited. This early decrease in pH is advantageous in suppressing the growth of many bacteria around the optimum pH 7.

[Experimental Example 4] Relationship between Lactic Acid Production and Oxygen Glucol 2.0% was added to the basic medium, three strains of lactic acid bacteria were inoculated, respectively, and aerobic static culture and anaerobic (BBL
In an anaerobic jar) static culture was performed. The results are shown in Table 4 and FIG.

From the above results, it is clear that KB-141 shows equal or more rapid lactic acid accumulation and pH decrease under anaerobic conditions under aerobic conditions, and can regulate stable quality silage regardless of aerobic or anaerobic conditions. became.

[Experimental Example 5] The culture conditions were set as follows, and the culture characteristics of the standard strains L. plantarum and KB-141 were compared.

 Culture place: PYG (polypeptone yeast glucose) medium Culture temperature: 30 ° C Culture time: 72 hours Results are shown in Table 5.

From the above results, it was quantitatively confirmed that KB-141 had a shorter generation time, a higher growth rate, and higher lactic acid production than the standard strain.

As is clear from the above results, the lactic acid bacterium KB- according to the present invention
141 has the excellent property of causing similar rapid growth and pH decrease due to lactic acid accumulation under both aerobic and anaerobic conditions, which means stable high quality silage by lactic acid fermentation, fermented sausage, It is extremely advantageous in adjusting pickled sugar. The KB-141 of the present invention can be used alone or in combination with other lactic acid bacteria having different properties. The KB-141 of the present invention is also useful when used in the production of lactic acid bacteria beverages and yogurt sugar foods.

[Brief description of drawings]

Figures 1 (a), (b), and (c) show the changes in the viable cell count at each temperature of 20 ° C, 30 ° C, and 37 ° C, and Fig. 2 (a),
(B) and (C) are graphs showing changes in the amount of lactic acid in the medium and the pH at each temperature of 20 ° C, 30 ° C, and 37 ° C.

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location C12P 7/56 9548-4B (C12N 1/20 C12R 1: 225) (C12P 7/56 C12R 1: 225)

Claims (1)

[Claims] 1. A lactic acid bacterium belonging to the genus Lactobacillus, which has the ability to ferment lactic acid in both aerobic and anaerobic atmospheres.
No. 0474), a novel lactic acid bacterium.