JPH0634709B2 - New lactic acid bacterium - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a novel lactic acid bacterium Lactobacillus C-590 (Lact
obacillus C-590). More specifically, the present invention relates to a novel lactic acid bacterium having both salt resistance and low temperature growth property and also having a property of suppressing the growth of harmful bacteria, which has a wide application in the food industry, the pharmaceutical industry and the like. .

(Problems to be solved by the invention) In various prepared foods and non-heated foods, such as pickles, salads, meat products, etc., it is a great problem to suppress the growth of harmful microorganisms such as Salmonella, Staphylococcus aureus, Escherichia coli. is there. Especially useful in non-heated meat products (lux ham, bacon, smoked beef, semi-dry sausage, soft salami sausage, liver paste, dry sausage, salami sausage, jerky, etc.) without adding bactericides or antibacterial agents. If it can be suppressed by using microorganisms, it has great value in the meat processing industry. Therefore, there is a strong demand from industry for the development of lactic acid bacteria which are salt-tolerant and have low temperature growth properties, and which suppress the growth of harmful microorganisms in high salt concentration products and contribute to the improvement of flavor.

(Prior art) As a lactic acid bacterium having both salt tolerance and low temperature growth property,
The following are known: Streptococcus faecalis, Streptococcus faecium, Pediococcus halophilus, Pediococcus acidilact
ici), Pediococcus
pentosaceus) Lactobacillus plantarum
illus plantarum) and the like.

(Means for Solving Problems) The present inventors have conducted various studies to search for lactic acid bacteria having salt tolerance and low temperature growth different from conventional lactic acid bacteria, and as a result, the lactic acid bacteria separated from the meat are used to store meat products and the like. It is a lactic acid bacterium that is effective in and contributes to flavor improvement, and that this bacterium is a new species that does not correspond to any known lactic acid bacterium,
The present invention has been completed.

That is, the present invention relates to Lactobacillus C-590 (Lacto
bacillus C-590). Representative strains of the present invention include Lactobacillus C-
590 (Lactobacillus C-590)
No.). This bacterium suspends about 2 g of a small piece of commercially available meat product in 10 ml of sterilized physiological saline, and 1 platinum loop of this suspension is smeared onto APT agar medium (5.5% salt added),
It was isolated from the characteristic colonies that appeared after culturing at 30 ° C for 2 days. Next, Lactobacillus C-5
The mycological properties of 90 are shown below.

(A) Bacterial morphology Bacterial morphology when cultivated in BL agar plate medium at 30 ° C. for 2 days (1) Cell size: 1.0 to 1.5 × 1.5 to 0.8 μm (2) Cell shape: rod-shaped (3) Motility: None (4) Spore formation: None (5) Gram stain: Positive (B) Growth state in each medium (1) Bacteria were spread on BL agar plate medium and anaerobically cultured at 30 ° C for 2 days Colony morphology Shape: Circular Size: 0.8-1.5 mm (diameter) Bump: Convex circle Color tone: Gray white and opaque Perimeter: Smooth Surface: Smooth and non-shiny (2) Briggs agar plate smeared with bacteria, 30 Colony morphology after anaerobically culturing for 2 days at ℃ Shape: Circular Size: 0.6 to 1.0 mm (diameter) Protuberance: Convex circle Color tone: Yellow-white and opaque Perimeter: Smooth Surface: Smooth and glossy (3) Briggs agar puncture Cultivation (30 ℃, 1-2 days) Grow linearly (4) APT liquid stationary culture (30 ℃, 1-2 days) Produce a residue.

(5) Briggs Liver liquid static culture (30 ° C, 1 to 2 days) It becomes turbid and a sediment is formed on the bottom.

(C) Physiological properties (1) Growth temperature: optimum temperature 25 to 30 ° C Growth range 8 to 42 ° C (2) Growth pH: optimum pH 6.2 to 6.8 Growth range pH 4.2 to 8.3 (3) For enzyme Attitude: Grows under facultative anaerobic and aerobic conditions, but grows better in the presence of CO ₂ gas (4) Does not reduce nitrate (5) Denitrification reaction: Negative (6) MR test: Positive (7) ) VP test: Negative (8) Indole formation: No formation (9) Hydrogen sulfide formation: No formation (10) Starch hydrolysis: Negative (11) Urease: Negative (12) Oxidase: Negative (13) Catalase : Negative (14) Liquefaction of gelatin: Negative (15) Litmus milk: Invariant (16) Gas production from glucose: Negative (17) Sodium chloride resistance: Grows at 10%, not at 12% (18) Sugar Optical rotation of lactic acid produced from: DL-type (19) Acid production from saccharides: arabinose-lactose-xylose-trehalose-rhamnose-melly Biose-Ribose + Raffinose-Glucose + Meletitose-Mannose + Starch-Fructose + Mannitol-Galactose + Sorbitol-Sucrose + Esculin + Maltose + Salicin + Cellobiose + Amygdalin + (+: Positive-: Negative) -590 is Gram positive,
It is a spore-free, facultative anaerobic, catalase-negative bacillus, and although DL-type lactic acid is produced from glucose, it is recognized as a homofermentative Lactobacillus lactic acid bacterium because it produces no gas.

In addition, since this bacterium grows even at 15 ° C, it is a subgenus of the genus Lactobacillus.
erium). The bacterial species belonging to Streptobacteria are classified into the following 13 species. ["Burger's Manual of Determinative Bacteriology 8th Edition" (1974) "The Procariotis Vol. 2" (1981)] That is, Lactobacillus (hereinafter referred to as L.) Plantarum (L. plantarum), L. Casei Subspecies (hereinafter referred to as ss.) Alactosus (L. casei s
s.alactosus), L. Casei ss. Rhamnosus (L.ca
sei ss.rhamnosus) L. Casei ss. Tolerance (L
． casei ss.tolerans), L. Casei ss. Casei (L
． casei ss.casei), L. Casei ss. Pseudoplantarum, L
． L. xylosus, L. L. curvatas, L. Corniformis (L.co
ryniformis), L. H. homoohiochi
i) L. Yamanashiensi (L.yamanashiensi
s), L. L. farciminisi, L
． It is L. alimentarius.

The above-mentioned "Burger's Manual of Determinative Bacteriology 8th Edition" (1974) and "The Procariotis Vol. 2" (1981), and further, "Idintification Method Microbiologicals" Part A "(1966)
And “The World of Enterobacteriaceae” written by Chimitsu Mitsuoka, Sobunsha (1980)
Year)) and the mycological properties of known strains classified into the subgenus Streptobacteria of the genus Lactobacillus and the mycological properties of Lactobacillus C-590 which is a representative strain of the present invention. It is shown in the following table. In the table, "acid from cellobiose and mannitol" The section on "genitality" is described in "The World of Enterobacteriaceae" by Michioka Michioka, 12
It is one of the elements used to classify bacterial species, as described on page 1, Moubunsha (1980).

As is clear from the above table, the bacterium of the present invention is different from any of the known bacteria classified into the subgenus Streptobacteria of the genus Lactobacillus in various mycological properties. That is, a known bacterium having the characteristic of the bacterium of the present invention that it produces an acid from cellobiose and not an acid from mannitol is L. Curvatas, L .; Casei ss. Tolerance, L. Falcipinis and L. There are four species of Alimentarius. Of these four species, those that do not grow at 45 ° C. and exhibit the optical-rotating DL-type property of lactic acid are L. Only Cultatas.

However, L. Curvatas is a simple bacillus characterized by a horseshoe-shaped curved cell shape. On the other hand, the bacterium of the present invention is
It is a club rod-shaped bacillus and has L. It is different from Curvata. Furthermore, in the acid production from sugar, L. It differs from cubatas in lactose, amycdarin, and rhamnose.

For the above reasons, the present invention does not correspond to any known bacterial species and is a new bacterial species.

Lactobacillus C590 has a good low temperature growth property, and reaches a growth arrest period in a liquid medium at 10 ° C. for 5 days. This bacterium shows good growth in a medium such as APT, MRS, Briggs Liver, BL. Furthermore, this bacterium can grow even at a salt concentration of 10%.

(Example 1) ... Culture example Yeast extract 75 g, peptone 125 g, glucose 10
0 g, sodium citrate 50 g, sodium chloride 50
g, dipotassium hydrogen phosphate 50 g, manganese chloride 1.4
g, magnesium sulfate 8 g, ferrous sulfate 0.4 g, sorbitan monooleate complex 2 g, thiamine hydrochloride 0.001 g, water 10 L medium (pH 6.5) 121
Sterilized at 15 ° C for 15 minutes and then cooled to 30 ° C. 10 L of the above medium was inoculated with 500 ml of a seed culture solution of Lactobacillus C-590 pre-cultured with a medium having the same composition for 20 hours at 30 ° C., and static culture was performed at 30 ° C. for 20 hours. Further, 1000 L of the same composition medium was sterilized at 90 ° C. for 30 minutes, cooled to 30 ° C., inoculated with 10.5 L of the culture solution, and statically cultured at 30 ° C. for 20 hours. The viable cell count at the end of the culture was 8.5 × 10 ⁸ / ml.

The culture broth after the culturing is subjected to a Sharpless centrifuge (150
The cells were harvested by suspending the bacterial cell concentrate in 200 L of sterilized physiological saline at 90 ° C. for 30 minutes, and again harvested by the centrifuge. The obtained microbial cell concentrate was resuspended in 20 L of a solution consisting of skim milk powder 10% (w / w) and sodium glutamate 1% (w / w) (preliminarily sterilized at 115 ° C. for 15 minutes), and then subjected to a conventional method. Vacuum freeze-dried according to. In 3.02 kg of the obtained dry powder, this bacterium contained 2.5 ×
The content was 10 ¹¹ / g.

(Example 2) ... application example Commercially available pork lean meat 450g, beef lean meat 300g pork fat 250
g, salt 25g, glucose 2.5g, potassium nitrate 0.5
g, 0.014 g of sodium nitrite and 0.01 g of the powder containing the present bacterium obtained in Example 1 and Staphylococcus aureus
IID-980 (enterotoxis production strain) normal broth medium culture solution (30 ° C., 24 hours culture, viable cell count 1.0 × 1)
( ⁰⁹ / ml) is diluted 1000 times with physiological saline, and 10 ml of the diluted solution is uniformly mixed with a silent cutter.

This homogeneous mixture contained 2.4 × 10 ⁶ / g of this bacterium and 1.0 × 10 ⁴ / g of Staphylococcus aureus. When this was aged at 18 ° C for 3 days, the bacterium was 4.
It increased to 6 × 10 ⁸ / g, and Staphylococcus aureus became 1.0 × 10 ² / g or less. The pH at this time is 5.2.
showed that. Thus, it was confirmed that this bacterium has an action of suppressing the reproduction of Staphylococcus aureus, which is a harmful microorganism.

(Effect of the Invention) Lactobacillus C-590, which is the bacterium of the present invention, is a bacterial species that suppresses the growth of harmful microorganisms such as Staphylococcus aureus in non-heated meat products and contributes to the storage stability of the product.
In addition, when this bacterium is added and aged as a starter during the production of various meat products, the effect of improving the flavor is remarkable.

As described above, this bacterium is a new species that does not correspond to any of the known Lactobacillus species and is a lactic acid bacterium having extremely excellent industrial properties.

Claims (1)

[Claims] 1. A novel lactic acid bacterium Lactobacillus C-590 having the following mycological properties (1) Gram-positive (2) Aspore-free spores (3) Bacilli (4) No motility (5) Facultative anaerobic (6) Catalase: Negative (7) Gas production from glucose: Negative (8) Growth temperature range: 8 to 42 ° C (9) Production from sugar Lactate rotation of lactic acid: DL type (10) From sugar Acid production: Lactose and rhamnose are negative (11) Sodium chloride resistance: 10% viable