• Journal of Microbiology and Biotechnology
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• v.24 no.6
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• pp.795-802
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• 2014

The aim of this study was to determine the effects of temperature and supplementation with skim milk powder (SMP) on the microbial and proteolytic properties during the storage of cottage cheese. Cottage cheese was manufactured using skim milk with 2% SMP and without SMP as the control, and then stored at $5^{\circ}C$ or $12^{\circ}C$ during 28 days. The chemical composition of the cottage cheese and the survival of the cheese microbiota containing starter lactic acid bacteria (SLAB) and non-starter culture lactic acid bacteria (NSLAB) were evaluated. In addition, changes in the concentration of lactose and lactic acid were analyzed, and proteolysis was evaluated through the measurement of acid soluble nitrogen (ASN) and non-protein nitrogen (NPN), as well as electrophoresis profile analysis. The counts of SLAB and NSLAB increased through the addition of SMP and with a higher storage temperature ($12^{\circ}C$), which coincided with the results of the lactose decrease and lactic acid production. Collaborating with these microbial changes, of the end of storage for 28 days, the level of ASN in samples at $12^{\circ}C$ was higher than those at $5^{\circ}C$. The NPN content was also progressively increased in all samples stored at $12^{\circ}C$. Taken together, the rate of SLAB and NSLAB proliferation during storage at $12^{\circ}C$ was higher than at $5^{\circ}C$, and consequently it led to increased proteolysis in the cottage cheese during storage. However, it was relatively less affected by SMP fortification. These findings indicated that the storage temperature is the important factor for the quality of commercial cottage cheese.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.283-283
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• 2017

The objective of the present study is to analyze the lactic acid bacteria (LAB) effects on rye silage fermentation at different stages. Different stages (Booting, Heading, Flowering, and Late flowering stage) of rye were collected from the National livestock farm, National Institute of Animal Science, South Korea. Rye sample was inculcated with lactic acid bacteria and incubated at the anaerobic condition for three months. The nutrient profile such as crude protein (CP), Acid detergent fibre, Neutral detergent fibre and total digestibility nutrients were increased in both control and LAB inculcated samples at all the stages of rye forage. The pH of rye silage was reduced at both stages by LAB inoculation as compared with control. The lactate content was increased in all stages of rye sample by LAB. The acetate concentration and butyrate was reduced in LAB inoculated rye sample. However, acetate concentration was slightly high in LAB inculcated rye at heading and late flowering stage. The LAB population was greater in LAB inoculated rye sample as compared with control sample. However, the massive population was noted in booting stage of rye than the other stages. It indicates the inoculated LAB is the main reason for increasing fermentation quality in the sample through pH reduction by lactate production. Overall results suggest that the isolated lactic acid bacterium is the potent strain that could be suitable for rye forage fermentation at different stages.

• The Korean Journal of Food And Nutrition
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• v.17 no.1
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• pp.72-79
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• 2004

This study was conducted to investigate the identification of lactic acid bacteria produced ν-aminobutyric acid(GABA) from traditional salt fermented anchovy. There was no appreciable difference in the number of lactic acid bacteria from fermented anchovy. Among the types of lactic acid bacteria, three strains of lactic acid bacteria produced ν-aminobutyric acid from those sample were identified temporary as name of Lactobacillus brevis BH-21, Lactobacillus rhamnosus BH-32 and Lactobacillus plantarum BH-38 by using gram positive identification(GPI) card and API 50 kit, respectively. 3 strains of Lactobacillus sp. were found to produce GAB A in the culture of filtrate. Lactobacillus brevis BH-21 produced GABA, some of which yielded 43.2 mg/mL GABA in the medium of 0.1% glucose, 0.1% yeast extract, 0.05% polypeptone, 0.002% MgSO$_4$$.$4H$_2$O, 0.001% FeSO$_4$$.$7H$_2$O, 0.01% NaCl, 0.1% monosodium glutamate, pH 6.0. This result suggests that Lactobacillus brevis BH-21 has the potential to be developed as a strain of GABA production.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.8
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• pp.1273-1283
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• 2020

Objective: This study investigated a method of preparing corn stover for Irpex lacteus (I. lacteus) treatment to improve its in vitro rumen degradability under non-sterile conditions. Methods: Corn stover was inoculated with Lactobacillus plantarum (L. plantarum), Lactobacillus buchneri (L. buchneri), and an equal mixture of these strains, and ensiled for 0, 3, 7, 14, and 28 days. After each period, a portion of the silage was sampled to assess the silage quality, and another portion of the silage was further treated with I. lacteus at 28℃ for 28 d. All the samples were analyzed for fermentation quality, chemical composition, and in vitro gas production (IVGP) as a measure of rumen fermentation capacity. Results: Lactic acid bacteria (LAB) was found to improve the silage quality of the corn stover, and the corn stover silage inoculated with L. plantarum produced more lactic acid and higher IVGP than other silage groups. The I. lacteus colonies flourished in the early stage of corn stover silage, especially on the 3-d corn stover silage inoculated with both L. plantarum and L. buchneri. This led to an 18% decrease in the acid detergent lignin content, and a 49.6% increase in IVGP compared with the raw stover. Conclusion: The combination of ensiling with the mixed LAB inoculation and I. lacteus treatment provided a cost-effective method for the improvement of the IVGP of corn stover from 164.8 mL/g organic matter (OM) to 246.6 mL/g OM.

• Journal of Microbiology and Biotechnology
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• v.16 no.5
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• pp.661-666
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• 2006

The present study represents the investigation of in vitro immunopotentiating activities of cellular fractions of major lactic acid bacteria found in kimchi (KLAB) and bifidobacteria. The macrophage cells, RAW264.7, were stimulated with heat-killed whole-cell, cell-wall, and cytoplasmic fractions of four strains of KLAB (Leuconostoc mesenteroides, Leuconostoc citreum, Lactobacillus plantarum, and Lactobacillus sake) and two strains of bifidobacteria (Bifidobacterium longum and Bifidobacterium lactis) each, and then the production of nitric oxide (NO) and cytokines including tumor necrosis $factor-\alpha\;(TNF-\alpha)$ and interleukin-6 (IL-6) was measured by Griess and ELISA assays, respectively. Heat-killed wholecell and cell-wall fractions-but not the cytoplasmic fraction-from all strains of KLAB significantly increased the production of NO in RAW264.7 cells, and all fractions from bifidobacteria exerted similar effects. In the production of $TNF-\alpha$, heat-killed whole-cell and cell-wall fractions of L. plantarum showed the strongest effect, followed by L. sake and B. lactis, whereas other KLAB fractions did not exert any effect. In the production of IL-6, only whole-cell and cell-wall fractions of L. plantarum were effective. These results, taken together, indicate that L. plantarum might playa critical role in the immunopotentiating activities of kimchi.

• Microbiology and Biotechnology Letters
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• v.35 no.4
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• pp.310-315
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• 2007

To investigate the effect of lactic acid bacteria in Andong-Soju fermentation and traditional nuruk maturation, several lactic acid bacteria were isolated from the Andong-Soju fermentation broth and traditionally matured nuruks using Lactobacilli MRS agar containing bromocresol purple. Among the isolated bacteria, ADS-L1 showed the highest lactic acid production and was dominant species in fermentation broth. Based on physiological characteristics and 16S rDNA sequencing results, the ADS-L1 was identified as Pediococcus acidilactici. The ADS-L1 grew well at $50^{\circ}C$, and under the acidic conditions at pH 4, whereas the ADS-L1 failed to grew by treatments of 12% (w/v) ethanol or 0.01N HCl. Considering the high temperature of nuruk above $50^{\circ}C$ during nuruk maturation and the high ethanol concentration of broth above 12% at the end-stage of Andong-Soju fermentation, these results suggested that the ADS-L1 is popular in matured nuruks and plays role in the early-stage of fermentation. Analysis of pH, brix, reducing sugar content, lactic acid production, and cell growth during the cultivation of ADS-L1 further suggested that the ADS-L1 may contribute the prevention of contamination by rapid and steady acidification of broth, and do not cause problems by rapid death at the end-stage of fermentation.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.2
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• pp.245-253
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• 2020

Objective: To develop the fermentation quality and chemical composition of alfalfa (Medicago sativa Lam.) silage, plants were inoculated with different lactic acid bacteria (LAB) strains at field 24 hours before harvest. Methods: The treatment groups were as follow: silage without additive as a control and inoculated with each strains of Lactobacillus brevis (LS-55-2-2), Leuconostoc citerum (L. citerum; L-70-6-1), Lactobacillus bifermentans (L. bifermentans; LS-65-2-1), Lactobacillus plantarum (L. plantarum; LS-3-3) and L. plantarum (LS-72-2). All the silages were stored at 25℃. Parameters such as pH, microorganism and volatile fatty acid contents, crude protein, neutral detergent fiber, acid detergent fiber, net gas, metabolizable energy, organic matter digestibility, dry matter intake and relative feed value were measured to determine fermentation quality, chemical compositions and relative feed value of alfalfa silages. Results: Significant differences were found among the control and treated groups in terms of pH and microorganism contents at all opening times and crude protein, net gas, metabolizable energy and organic matter digestibility of final silage. The pH values ranged from 4.70 to 5.52 for all treatments and control silage had the highest value of overall treatments at T₇₅d silages. Volatile fatty acid of silages was not influenced significantly by inoculations. However, lactic acid content of L. bifermentans (LS-65-2-1) was higher than the other treatments. The highest metabolizable energy and organic matter digestibility were recorded from L. citerum (L-70-6-1) inoculation. In addition, no significant differences were found among treatments in terms of neutral detergent fiber, acid detergent fiber, dry matter intake and relative feed value. Conclusion: Among the treated LAB isolates, L. bifermentans came into prominence especially in terms of organic acid composition and quality characters of silages.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.12
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• pp.1873-1881
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• 2019

Objective: Information regarding the vitamin content of silage is limited. This study investigated the changes in the vitamin content of alfalfa and Chinese leymus silages with or without a lactic acid bacterial inoculant. Methods: Alfalfa at the early flowering stage and Chinese leymus at the full-bloom stage were harvested. The treatments for each forage type were control (deionized water only) and $1{\times}10^6$ colony-forming units Lactobacillus plantarum (LP)/g fresh matter. After 45 days of ensiling, all silages were sampled for evaluating the vitamin content, fermentation quality and chemical composition. Results: The LP inoculant decreased the pH value and ammonia nitrogen content of the alfalfa and Chinese leymus silages and significantly (p<0.05) increased the lactic acid, acetic acid concentrations and Flieg's points. Prior to ensiling, the levels of five B-group vitamins (thiamin, riboflavin, niacin, pantothenic acid, and pyridoxine) and ${\alpha}$-tocopherol in alfalfa were significantly (p<0.01) higher than those in Chinese leymus. Ensiling decreased the levels of the five B-group vitamins in both alfalfa and Chinese leymus while increasing the ${\alpha}$-tocopherol content of Chinese leymus. The thiamin, riboflavin, niacin and pantothenic acid levels in the LP-treated silage were significantly (p<0.05) lower than those in the untreated silage for the alfalfa and Chinese leymus. The ${\alpha}$-tocopherol content in the LP-treated alfalfa silage was significantly (p<0.05) higher than that in the untreated alfalfa silage. There was no significant (p>0.05) difference in pyridoxine content between the untreated and LP-treated silages for both forages. Conclusion: With or without LP inoculation, the levels of the five B-group vitamins (thiamin, riboflavin, niacin, pantothenic acid, and pyridoxine) in alfalfa and Chinese leymus decreased after 45 days of ensiling, while the ${\alpha}$-tocopherol content of Chinese leymus increased. The LP inoculant improved the fermentation quality of both the alfalfa and Chinese leymus silages but increased the thiamin, riboflavin, niacin, and pantothenic acid loss in the two forages after fermentation.

• Korean Journal of Food Science and Technology
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• v.33 no.5
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• pp.603-610
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• 2001

The quality characteristics of soy yogurt prepared with different proteolytic enzymes and starter culture were evaluated. In order to facilitate the growth of lactic acid bacteria and subsequent production of lactic acid, soy protein isolate(SPI) was hydrolyzed using three kinds of proteases; one extracted from Aspergillus oryzae, bromelain and ${\alpha}-chymotrypsin$. The cultural systems employed thereafter for lactic fermentations were: 1) Bifidobacterium bifidum, 2) B. bifidum and Lactobacillus acidophilus, 3) B. bifidum and Lactobacillus bulgaricus. In soy yogurt, pH was more decreased by mixed culture method than single culture method with the accumulation of lactic acid. Viable cells of lactic acid bacteria in soy yogurts were measured $10^8$ CFU/g by the single culture method while $10^9$ CFU/g by the mixed culture method except ${\alpha}-chymotrypsin$ treatment. The amount of free amino acids in soy yogurts were substaintially increased by enzyme treatment. Viscosity was decreased by enzyme treatment, resulting in higher viscosity by ${\alpha}-chymotrypsin$ treatment. Water holding capacity was found to be higher in the single culture method in case of enzyme treatment. Among the various volatile flavor components isolated and identified after enzyme hydrolysis, acetaldehyde, ethanol, diacetyl, butyl alcohol contents tended to increase by lactic fermentation.

• Korean Journal of Food Science and Technology
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• v.25 no.2
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• pp.130-135
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• 1993

A curd yogurt was prepared from milk added with skim milk powder of four kinds of cereal. The effect of cereals at 2%(w/v) level on acid production by lactic acid bacteria in milk was investigated. The effect of cereals on quality of curd yogurt (apparent viscosity, sensory property) was also examined. Addition of cereals markedly stimulated acid production by lactic acid bacteria. Among three organisms tested, L. acidophilus produced more acid than others. Apparent viscosity of curd yogurt added with corn was the highest while that with barley was the lowest. Curd yogurt fermented with L. acidophilus showed characteristics of thioxotropic flow. Apparent viscosity of curd yogurt added with cereal markedly increased between 6 and 24 hours of fermentation. Sensory property of curd yogurt added with wheat was judged as better than reference sample, but that with barley was lodged as the worst among all samples.