JPH06104059B2 - New lactic acid bacteria - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel lactic acid bacterium belonging to the genus Lactobacillus.

[Conventional technology]

Silage, which is a feed for livestock, is produced by anaerobic fermentation by cutting grass and storing it in a silo.

[Problems to be Solved by the Invention]

However, immediately after cutting silage 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. Therefore, in order to feed the livestock, it is necessary for the regenerated raw material itself to breathe, the oxygen between the stacked raw materials to be sufficiently consumed to reach the anaerobic atmosphere, and the anaerobic fermentation to proceed. It took a considerable amount of time. In such a case, aerobic bacteria may grow before the silage raw material reaches the anaerobic atmosphere, and the raw material may be damaged by microorganisms.

Further, even when an anaerobic atmosphere is reached, butyric acid bacteria, etc., which emit an unpleasant odor of livestock, may proliferate first instead of lactic acid bacteria, so that good anaerobic fermentation cannot always be realized.

Therefore, the present invention solves the problems of the above-mentioned conventional techniques, and provides a novel lactic acid bacterium that surely promotes lactic acid fermentation, which has high nutritional value and is preferred by livestock immediately after cutting the silage raw material such as grass. The purpose is to

[Means for Solving the Problems]

To achieve the above-mentioned object, the characteristic constitution of the novel lactic acid bacterium according to the present invention belongs to the genus Lactobacillus, and has the ability to prepare silage in both aerobic and anaerobic atmospheres Lactobacillus KB-292 strain. (Ministry of Microbiological Research, No. 10475).

[Action / effect]

The present inventors have made great efforts to discover lactic acid bacteria that actively promote lactic acid fermentation from the initial stage of storage of silage raw material, and as a result, compared with conventional lactic acid bacteria, even in an aerobic atmosphere or in an anaerobic atmosphere. Also in the above, we succeeded in finding a bacterium having a sufficient silage preparation ability especially in the initial stage of storage.

The lactic acid bacterium and Lactobacillus KB-292 strain according to the present invention have the following properties.

Culture medium LCM medium pH: 6.8, which shows good growth when cultured at 37 ℃ for 24 hours.

Form Bacillus spores None Gram stain Positive Physiological properties Lactic acid fermentation Homo-type catalase None Growth temperature 30-35 ℃ Growth temperature 15-40 ℃ Sugar assimilation (comparison with Lactobacillus plantarum standard bacteria Lactobacillus, this strain Plantarum standard bacteria glucose ++ galactose ++ sorbose − − sucrose ＋ + maltose ＋ + cellobiose ＋ ＋ trehalose ＋ − lactose ＋ ＋ ＋ melibiose ＋ ＋ ＋ meletitose ＋. Xylose-L-arabinose + -Ribose ++ Rhamnose --- Ethanol--Glycerol--Erythritol--Galactitol--Mannitol ++. Alpha.-Me-Glucoside--Salicin ++ Citrate-- Inositol --- Mannose ++ As for the assimilation of the above sugars, BTB was added to the basic medium having the following composition, sterilized at 121 ° C for 20 minutes, and each sugar was added to 2% after cooling. , Lactobacillus suspension 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 it is recognized that it is a species of Lactobacillus plantarum. However, Lactobacillus plantarum has assimilation ability in each saccharide of trehalose, raffinose, and L-arabinose, and as described later, the amount of lactic acid produced in both aerobic and anaerobic atmospheres in the early stage of culture. There is a notable difference in the large number and the conspicuous decrease in pH value. Considering these facts, it was confirmed that this strain is a novel lactic acid bacterium belonging to the genus Lactobacillus, and Lactobacillus KB-292
The strain was named.

This strain, Lactobacillus KB-292, is
No. 0475 has been deposited at the Institute of Microbial Technology of the Agency of Industrial Science and Technology.

〔Example〕

Next, the specific lactic acid-producing ability of this strain will be described based on the experimental results.

FIGS. 1 (a), (b), and (c) show changes in pH when the Lactobacillus plantarum standard strain and this strain were cultured for up to 96 hours at respective culture temperatures of 20, 30, and 37 ° C., respectively. Show.

The measurement at this time was carried out over time by adding 2.0% of glucose to a basal medium consisting of 0.5% polypeptone, 0.5% yeast extract and 0.5% dipotassium phosphate, and then inoculating the strain.

From this figure, this strain is more
It is understood that it results in a decrease in pH. This tendency is more remarkable as the culture temperature is higher.

Then, the amount of lactic acid produced was measured under the same conditions as the above-mentioned pH measurement, and the results are shown in FIGS. 2 (a), (b) and (c).
At this time, the amount of lactic acid produced was measured by the titration method based on the following formula.

Lactic acid amount (%) = N / 10 NaOH drop constant × f × 0.009 × 100 / sample amount Here, the N / 10 NaOH drop constant means the 1/10 normal NaOH drop constant, and f is a correction factor for titration. Yes, 0.009 is N
It is the equivalent amount of lactic acid per 1 cc of aOH solution.

As for the result of the figure, a tendency similar to that of the result of FIG. 1 can be seen.

Furthermore, the influence of the atmosphere was examined for the Lactobacillus plantarum standard strain and this strain.

FIGS. 3 (a) and 3 (b) show the measurement results of pH changes with the passage of culture time in an aerobic atmosphere and an anaerobic atmosphere.

The same medium as described above was used, and this was placed in an aerobic atmosphere by statically culturing at 30 ° C., while it was placed in an anaerobic jar manufactured by BBL to make it an anaerobic atmosphere.

This strain, in both aerobic and anaerobic cases,
A sharp drop in pH is observed during the first 24 hours of culture.

Lactic acid production was measured under similar conditions, and the results are shown in FIGS. 4 (a) and 4 (b).

Also in this case, a rapid amount of lactic acid was observed in the first 24 hours of the culture, and the results corresponding to the tendency of pH decrease shown in FIGS. 3 (a) and 3 (b) were obtained.

From the above results, it is clear that the lactic acid bacterium of this strain actively promotes lactic acid fermentation in both the aerobic atmosphere and the anaerobic atmosphere, especially in the initial stage of culture, as compared with conventional lactic acid bacteria. Therefore, by inoculating the silage raw material with this strain, even at the initial stage of storage when the raw material atmosphere is aerobic, the pH is rapidly lowered to grow the lactic acid bacteria, and it is possible to provide a silage that is high in nutritional value and favored by livestock. Therefore, this strain has sufficient silage preparation ability.

The strain is adaptable to a wide range of silage raw materials, and can be used for agricultural wastes such as rice straw and straw as well as various grasses.

[Brief description of drawings]

Figure 1 shows the time course of pH of Lactobacillus plantarum standard strain and this strain at different culture temperatures, Figure 2 shows the time course of the amount of lactic acid produced, and Figure 3 shows the pH in different atmospheres. FIG. 4 is a view showing a change over time in the amount of lactic acid produced, and FIG.

Claims (1)

[Claims] 1. A lactic acid bacterium belonging to the genus Lactobacillus, which is a Lactobacillus KB-292 strain (Microtechnology Research Institute No. 10475) having the ability to prepare silage in both aerobic and anaerobic atmospheres. Characteristic novel lactic acid bacteria.