• Microbiology and Biotechnology Letters
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• v.48 no.2
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• pp.138-147
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• 2020

Various microorganisms play important roles in food fermentation, food spoilage, and agriculture. In this study, the biotype of 54 yeast and bacterial strains having high potential for utilization in food and agriculture, including Candida spp., Lactobacillus spp., and Acetobacter spp., were characterized by matrix-assisted laser desorption/ionization time-of flight mass spectrometry (MALDI-TOF MS). This characterization using a fast and robust method provides much-needed information on the selected microorganisms and will facilitate effective usage of these strains in various applications. Importantly, the unique protein profile of each microbial species obtained from this study was used to create a database of fingerprints from these species. The database was validated using microbial strains of the same species by comparing the mass spectra with the created database through pattern matching. The created reference database provides crucial information and is useful for further utilization of a large number of valuable microorganisms relevant to food and agriculture.

• Microbiology and Biotechnology Letters
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• v.49 no.2
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• pp.201-209
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• 2021

Agarwood (Aquilaria spp) has high economic value. However, essential oil production from agarwood is a time-consuming process. Additionally, agarwood leaves have not been utilized even though they contain various bioactive ingredients. In this study, agarwood leaves were fermented using Lactobacillus plantarum ATCC 8014 with or without Stevia (4, 8, and 12%; v/v). The fermented fluid was mixed with maltodextrin (15%; w/v) and subjected to spray drying (inlet temperature, 120℃; outlet temperature, 65-70℃). The contents of polyphenols, polysaccharides, saponins, and flavonoids and the viability of L. plantarum were determined. Fermentation enhanced the levels of bioactive compounds. The contents of polyphenol (69.19 ± 4.05 mg GAE/g of sample), polysaccharide (20.75 ± 0.98 mg GE/g of sample), saponin (305.23 ± 4.21 mg OAE/g of sample), and flavonoid (7.86 ± 0.72 mg QE/g of sample), and the viability of L. plantarum (8.72 ± 0.17 log CFU/ml) were markedly upregulated in the samples containing Stevia (12%; v/v). This indicated that the supplementation of Stevia during fermentation decreases the fermentation time (9 h), upregulates bioactive compound production in agarwood leaves, enhances microencapsulation during spray drying, and increases the viability of L. plantarum under simulated gastric digestion conditions.

• Journal of The Korean Society of Grassland and Forage Science
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• v.39 no.3
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• pp.132-140
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• 2019

Fermented total mixed ration (TMR) is a novel feed for ruminants in South Korea. The purpose of this study was to evaluate the effects of lactic acid bacteria (LAB) on the quality of TMR and in vitro ruminal fermentation. Strains of three LAB spp. (Lactobacillus plantarum, L. brevis, L. mucosae) were used in fermentation of TMR. Inoculations with the three LAB spp. lowered pH and increased concentrations of lactic acid, acetic acid, and total organic acid compared to non-LAB inoculated control (only addition of an equivalent amount of water) (p<0.05). Bacterial composition indicated that aerobic bacteria and LAB were higher. However, E. coli were lower in the fermented TMR than those in the control treatment (p<0.05). Among the treatments, L. brevis treatment had the highest concentration of total organic acid without fungus detection. Gas production, pH, and ammonia-nitrogen during ruminal in vitro incubation did not differ throughout incubation. However, ruminal total VFA concentration was higher (p<0.05) in the LAB spp. treatments than the control treatment at 48 hours. Overall, the use of L. brevis as an inoculant for fermentation of high moisture. TMR could inhibit fungi growth and promote lactic fermentation, and enhance digestion in the rumen.

• Korean Journal of Food Science and Technology
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• v.23 no.6
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• pp.689-694
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• 1991

Jangsu, a Korean ancient non-alcoholic beverage made by lactic acid fermentation of cooked rice, was prepared and the microbial characteristics were investigated. The periodic removal of fermented product and the addition of newly made cooked rice and cold water as new substrate enhanced the growth of lactic acid forming bacteria but supressed the growth of proteolytic bacteria. The important microorganisms in jangsu were Lactobacillus, Lactococcus, Pediococccus and Leuconostoc species. Lactococcus thermophilus, Lactobacillus coryniformis and Leuconostoc mesenteroides were identified. The isolated strains were cultivated and used as starter culture of jangsu. Some useful strains were selected which were able to produce acceptable flavor and sufficient amount of acid lowering the pH to near 4.0.

• Journal of Microbiology and Biotechnology
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• v.23 no.10
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• pp.1357-1364
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• 2013

Human skin is continuously exposed to ultraviolet (UV)-induced photoaging. UVA increases the activity of MMP-1 in dermal fibroblasts through mitogen-activated protein kinase (MAPK), p38, signaling. The irradiation of keratinocytes by UVA results in the secretion of the inflammatory cytokine, tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), and the stimulation of MMP-1 in normal human dermal fibroblasts (NHDFs). Lipoteichoic acid (LTA) is a component of the cell wall of gram-positive Lactobacillus spp. of bacteria. LTA is well known as an anti-inflammation molecule. LTA of the bacterium Lactobacillus plantarum has an anti-photoaging effect, but the potential anti-photoaging effect of the other bacteria has not been examined to date. The current study showed that L. sakei LTA (sLTA) has an immune modulating effect in human monocyte cells. Our object was whether inhibitory effects of sLTA on MMP-1 are caused from reducing the MAPK signal in NHDFs. It inhibits MMP-1 and MAPK signaling induced by UVA in NHDFs. We also confirmed effects of sLTA suppressing TNF-${\alpha}$ inducing MMP-1 in NHDFs.

• Korean Journal of Veterinary Service
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• v.29 no.3
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• pp.277-285
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• 2006

Plasmids are covalently closed circular molecules of DNA that are stably inherited and replicate somewhat independently of the bacterial chromosome. Genes carried on plasmids can mediate a wide variety of important functions, including antibiotics (R plasmids) and heavy metals resistance, toxins production, cell penetration, iron chelation, complement resistance, and metabolic characteristics such as sucrose and lactose fermentation. Fifty strains of lactobacilli were isolated from 26 staters and 29 fermented milk products. They were classified 27 strains as Lactobacillus paracasei subsp paracasei, 11 stains as Lactococcus lactis subsp cremoris, 6 strains as L delbrueckii subsp lactis, 4 strains as L acidophius, and 2 strains as L delbrueckii subsp bulgaricus. All of these strains were examined for drug resistance and transferability of R plasmids. All of the isolates were sensitive to Am, C, CF, E, NB, P, T, and Te. But resistant to SXT 94% (47 strains), K 66% (33 strains), S 56% (28 strains), ENR 50% (25 strains), NOR 38% (19 strains) CIP 38% (19 strains), GM 16% (8 strains), and N 14% (7 strains), in order. And 32 different resistant patterns were found. The most frequently encountered patterns were CIP-ENR-K-NOR-S-SXT (5 strains). In vitro R plasmids transfer experiment, 57 antibiotic resistant strains which were not transfer to the recipient 2 Escherichia coli strains by conjugation, These results indicate that Lactobacillus in internal trade market' stater recognize R factor but transmissible R plasmid is not existed.

• Journal of Dairy Science and Biotechnology
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• v.33 no.1
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• pp.83-91
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• 2015

Yogurt is a product of the acidic fermentation of milk, which affects the survival of lactic acid bacteria (LAB). The aim of this present study was to examine the survival and acid stress response of Lactobacillus rhamnosus GG to low pH environment. The survival of LAB in commercial yogurt was measured during long-term storage. The enumeration of viable cells of LAB was determined at 15-day intervals over 52-weeks at $5^{\circ}C$. L. acidophilus, L. casei, and Bifidobacterium spp. showed low viability. However, L. rhamnosus GG exhibited excellent survival throughout the refrigerated storage period. At the end of 52-weeks, L. rhamnosus GG survived 7.0 log10 CFU/mL. $F_0F_1$ ATPase activity in L. rhamnosus GG at pH 4.5 was also evaluated. The ATPase activities of the membranes were higher when exposed at pH 4.5 for 24 h. The survival of L. rhamnosus GG was attributable to the induction in $F_0F_1$ ATPase activity. In addition, the mRNA expression levels of acid stress-inducible genes at low pH were investigated by qRT-PCR. clpC and clpE genes were up-regulated after 1 h, and atpA and dnaK genes were up-regulated after 24 h of incubation at pH 4.5. These genes could enhance the survival of L. rhamnosus GG in the acidic condition. Thus, the modulation of the enzymes or genes to assist the viability of LAB in the low pH environment is thought to be important.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.2
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• pp.198-205
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• 2017

Objective: This study aimed to investigate the effects of single or/and double strains of probiotic supplement on feed efficiency, growth performance, and microbial population in distal gastrointestinal tract (GIT) of weaning rabbits. Methods: Sixty-four weaning (28 days old) New Zealand White rabbits were randomly distributed into four groups with treatments including: basal diet without probiotic supplement (control) or supplemented as follows: $1{\times}10^6cfu/g$ B. subtilis (BS group), $1{\times}10^7cfu/g$ L. acidophilus (LA group), or $0.5{\times}10^6cfu/g$ B. subtilis plus $0.5{\times}10^7cfu/g$ L. acidophilus (BL group). During the research, the male and female rabbits were fed separately. Body weight of the rabbits was recorded at 28, 42, and 70 d of age. Results: There was an increase (p<0.05) in body weight gain for the LA group at 42 d. Rabbits fed BL responsed with a greater growth (p<0.05) and better feed conversion ratio (p<0.05) than those fed with no probiotic. Digestibility coefficients of dry matter, organic matter, crude protein, neutral detergent fiber, and gross energy were higher (p<0.05) in LA and BL groups than those in the control group. Male rabbits had higher (p<0.05) Bacilli spp. and Coliformis spp. in the ileum than female rabbits. Rabbits supplemented with BS had greater (p<0.05) numbers of bacilli in all intestinal segments than those receiving no probiotic, whereas intestinal Lactobacilli populations were greater (p<0.001) in the LA and BL diets compared to control. Average intestinal coliform populations were lowest (p<0.05) in the rabbits supplemented with LA as compared to those fed the control and BS. Conclusion: Supplementation of L. acidophilus alone or in combination with B. subtilis at a half of dose could enhance number of gut beneficial bacteria populations, nutrient digestibility, cecal fermentation, feed efficiency, and growth performance, but rabbits receiving only B. subtilis alone were not different from the controls without probiotic.

• Microbiology and Biotechnology Letters
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• v.47 no.4
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• pp.509-514
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• 2019

We investigated the beneficial effects of Ecklonia cava by-product (ECB), a residual product obtained after polyphenol extraction from Ecklonia cava, on normal rats. Male Sprague-Dawley rats were divided into the following three groups: Control group (NC), received basal diet; ECB 0.1 group, received basal diet supplemented with 0.1% ECB for 21 days; ECB 0.5 group, received basal diet supplemented with 0.5% ECB for 21 days. The productivity, serum immunoglobulin level, expression levels of muscle-related genes, and cecal microflora were measured in all the treatment groups to evaluate the potential use of ECB as a feed additive. The ECB 0.1 group exhibited enhanced expression of Myod, Myog, and Igf1 genes, which increased the body weight of rats. Additionally, treatment with ECB increased the cecal Lactobacillus spp. counts and the serum immunoglobulin G levels in rats. Thus, ECB can effectively increase body weight and can be a potential feed additive for improving growth.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.3
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• pp.417-421
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• 1999

This experiment examined the effects of feeding Aspergillus oryzae (AO) culture to laying hens, on fecal microbial populations, fecal pH and moisture content, egg quality, and metabolizabilities of several nutrients. Sixteen commercial 38-wk-old laying hens were randomly allotted to four diets: control; with 0.15% locally produced AO culture; with 0.3% locally produced AO culture, and; or with 0.3% imported AO. Each treatment consisted of four replicates (cages) containing one bird per cage according to a completely randomized design. After 4 wk, AO were recovered in the feces of birds fed the AO diets, indicating that AO might pass through the fore-gut alive and become active in the hind gut. The number of Lactobacillus spp. in feces was higher in all treated groups than that of the control, indicating that AO would provide a beneficial environment for the Lactobacillus spp. to proliferate in the intestine. The number of fecal E. coli was significantly reduced by the addition of AO. A similar trend was also found for aerobic bacteria. Although not significant, fecal moisture contents tended to be reduced by the addition of AO. Fecal pH was not significantly different among the treatments. The addition of AO did not affect the various economic traits of eggs. Metabolizabilities of gross energy and dry matter measured during the 5th wk were increased by the AO supplementation. It appears that AO culture alone could be used as a probiotic supplement for layers.