• Food Science of Animal Resources
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• v.31 no.4
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• pp.513-520
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• 2011

In order to develop a new starter culture for fermented milk, Lactobacillus fermentum LC272 was isolated from raw milk and its physiological characteristics were investigated. The vitamin $K_2$ concentration of L. fermentum LC272 was $184.94{\mu}g/L$ in Rogosa medium and $63.93{\mu}g/L$ in the reconstituted skim milk. The optimum growth temperature for L. fermentum LC272 was determined to be $40^{\circ}C$ and it took 24 h for the pH to reach 5.2 under this condition. L. fermentum LC272 was more sensitive to rifampicin relative of the other 15 different antibiotics tested, and showed most resistance to streptomycin. L. fermentum LC272 showed higher activities to leucine arylamidase and acid phosphatase. It was comparatively tolerant to bile juice and acid and displayed high resistance against Salmonella Typhimurium and Staphylococcus aureus with rates of 82.9 and 86.3% respectively. These results demonstrated that L. fermentum LC272 could be an excellent starter culture for fermented milk with high levels of vitamin $K_2$ production.

• Food Science of Animal Resources
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• v.30 no.6
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• pp.957-965
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• 2010

To develop a new starter culture for fermented milk, Streptococcus macedonicus LC743 was isolated from raw milk and its physiological characteristics were investigated. S. macedonicus LC743 showed good immunomodulating activity compared to the index LAB starters tested. The optimum growth temperature of S. macedonicus LC743 was $40^{\circ}C$, and it took 18 h to reach pH 4.34 under these conditions. S. macedonicus LC743 showed higher sensitivity to novobiocin in a comparison of 15 different antibiotics and showed the highest resistance to gentamycin. It also showed higher activities of leucine arylamidase and acid phosphatase. Moreover, it was comparatively tolerant to bile juice and acid and displayed high resistance to Escherichia coli, Salmonella Typhimurium, Staphylococcus aureus with rates of 80.0%, 68.42%, and 81.54% respectively. These results demonstrate that S. macedonicus LC743 could be an excellent starter culture for fermented milk with a high level of immunomodulating activity.

• Food Science of Animal Resources
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• v.30 no.2
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• pp.223-231
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• 2010

In order to develop a new starter for fermented milk, Lactobacillus paracasei subsp. paracasei BFI46 (BFI46) obtained from new-born infant feces was investigated for physiological characteristics. Good immunomodulating activity was evident compared with commercial lactic acid bacteria starter cultures. The optimum growth temperature of BFI46 was $40^{\circ}C$ with 12 h required to reach pH 4.3. Testing with 13 different antibiotics revealed greatest sensitivity of BFI46 to penicillin- G and chloramphenicol, and heightened resistance to neomycin, kanamycin and polymyxin. BFI46 displayed higher esterase activities compared to 18 other enzymes, was comparatively tolerant to bile juice and able to survive at pH 2 for 3 h, and displayed high resistance against Escherichia coli and Salmonella Typhimurium with a survival rate of 57.14% and 96.36%, respectively. The results indicate that BFI46 could be an excellent starter culture for fermented milk with high level of immunomodulating activity.

• Microbiology and Biotechnology Letters
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• v.46 no.4
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• pp.334-345
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• 2018

Spore-forming Bacillus species are commercially available probiotic formulations for application in humans. They have health benefits and help prevent disease in hosts by combating entero-pathogens and ameliorating antibiotic-associated diarrhea. However, the molecular and cellular mechanisms of these benefits remain unclear. Here, we report the draft genome of a potential probiotic strain of Bacillus clausii B106. We mapped and compared the probiotic profile of B106 with other reference genomes. The draft genome analysis of B106 revealed the presence of ADI pathway genes, indicating its ability to tolerate acidic pH and bile salts. Genes encoding fibronectin binding proteins, enolase, as well as a gene cluster involved in the biosynthesis of exopolysaccharides underscored the potential of B106 to adhere to the intestinal epithelium and colonize the human gut. Genes encoding bacteriocins were also detected, indicating the antimicrobial ability of this isolate. The presence of genes encoding vitamins, including Riboflavin, Folate, and Biotin, also indicated the health-promoting ability of B106. Resistance of B106 to multiple antibiotics was evident from the presence of genes encoding resistance to chloramphenicol, ${\beta}$-lactams, Vancomycin, Tetracycline, fluoroquinolones, and aminoglycosides. The findings indicate the significance of B. clausii B106 administration during antibiotic treatment and its potential value as a probiotic strain to replenish the health-promoting and disease-preventing gut flora following antibiotic treatment.

• Journal of Dairy Science and Biotechnology
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• v.38 no.4
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• pp.207-221
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• 2020

This study aimed to investigate the physiological characteristics and anti-obesity effects of milk fermented by L. plantarum KI134. The lipase, α-amylase, and α-glucosidase inhibitory activities of milk fermented by L. plantarum KI134 was 94.57±1.25%, 9.44±2.85%, and 2.74±1.24% (10 fold dilution), respectively. L. plantarum KI134 showed higher sensitivity to clindamycin and erythromycin in comparison to sixteen different antibiotics. It demonstrated the highest resistance toward ampicillin and vancomycin. The strain showed higher β-galactosidase, leucine arylamidase, valine arylamidase, acid phosphatase, β-glucosidase, and N-acetyl-β-glucosaminidase activities compared to other enzymes. It also did not produce carcinogenic enzymes, such as β-glucuronidase. The survival rate of L. plantarum KI134 in 0.3% bile was 96.90%. Moreover, the strain showed a 91.45% survival rate at a pH of 2.0. L. plantarum KI134 has resistance to Escherichia coli, Salmonella Typhimurium, Listeria monocytogenes, and Staphylococcus aureus at the rates of 70.00%, 68.18%, 59.05%, and 40.63%, respectively. L. plantarum KI134 (23.01%) showed higher adhesion ability than the positive control (16.32%) L. rhamnosus GG. These results demonstrated that milk fermented by L. plantarum KI134 demonstrated an anti-obesity effect under in vitro conditions, with confirmed potential as a probiotic.

• BMB Reports
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• v.56 no.11
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• pp.600-605
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• 2023

Intrahepatic cholangiocarcinoma (ICC) is a bile duct cancer and a rare malignant tumor with a poor prognosis owing to the lack of an early diagnosis and resistance to conventional chemotherapy. A combination of gemcitabine and cisplatin is the typically attempted first-line treatment approach. However, the underlying mechanism of resistance to chemotherapy is poorly understood. We addressed this by studying dynamics in the human ICC SCK cell line. Here, we report that the regulation of glucose and glutamine metabolism was a key factor in overcoming cisplatin resistance in SCK cells. RNA sequencing analysis revealed a high enrichment cell cycle-related gene set score in cisplatin-resistant SCK (SCK-R) cells compared to parental SCK (SCK WT) cells. Cell cycle progression correlates with increased nutrient requirement and cancer proliferation or metastasis. Commonly, cancer cells are dependent upon glucose and glutamine availability for survival and proliferation. Indeed, we observed the increased expression of GLUT (glucose transporter), ASCT2 (glutamine transporter), and cancer progression markers in SCK-R cells. Thus, we inhibited enhanced metabolic reprogramming in SCK-R cells through nutrient starvation. SCK-R cells were sensitized to cisplatin, especially under glucose starvation. Glutaminase-1 (GLS1), which is a mitochondrial enzyme involved in tumorigenesis and progression in cancer cells, was upregulated in SCK-R cells. Targeting GLS1 with the GLS1 inhibitor CB-839 (telaglenastat) effectively reduced the expression of cancer progression markers. Taken together, our study results suggest that a combination of GLUT inhibition, which mimics glucose starvation, and GLS1 inhibition could be a therapeutic strategy to increase the chemosensitivity of ICC.

• Food Science and Biotechnology
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• v.15 no.5
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• pp.677-682
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• 2006

Strain HY701 was isolated from human feces for probiotic use by selecting highly resistant isolates to artificial gastric acid and bile acid. Strain HY701 was identified as Lactobacillus reuteri using 16S rDNA sequencing, and tentatively named L. reuteri HY701. The resistance of L. reuteri HY701 to artificial gastric acid (PH 2.5) was high with a survival rate of over 90%. L. reuteri HY701 also showed high tolerance to artificial bile acid after incubation in artificial gastric acid. Using the API ZYM test kit, the carcinogenic enzymes (${\beta}$-glucuronidase and (${\beta}$-glucosidase were not detected with L. reuteri HY70l, while the beneficial enzyme (${\beta}$-galactosidase was weakly detected. L. reuteri HY701 was sensitive to $100\;{\mu}g/mL$ nisin, $20\;{\mu}g/mL$ roxithromycin, $15\;{\mu}g/mL$ erythromycin, but resistant to $20\;{\mu}g/mL$ streptomycin, $10\;{\mu}g/mL$ tetracycline, $20\;{\mu}g/mL$ ciprofloxacin, $20\;{\mu}g/mL$ nystatin, $20\;{\mu}g/mL$ gentamycin, $10\;{\mu}g/mL$ doxycycline, $10\;{\mu}g/mL$ chloramphenicol, and $20\;{\mu}g/mL$ ampicillin. L. reuteri HY701 was shown to possess bactericidal activity as it inhibited the growth of Listeria monocytogenes ATCC 19111 and Escherichia coli JM109 completely within 24 hr of incubation. These results indicate that L. reuteri HY701 could be used as a probiotic strain.

• Microbiology and Biotechnology Letters
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• v.47 no.4
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• pp.498-508
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• 2019

Bacillus species were isolated from iru, a traditional fermented condiment in Nigeria. Polyphasic approach was used to evaluate the phylogenetic relationship and strain sub-type of the isolated species. Additionally, the phylogenetic profiles of the species isolated from iru were compared with those of bacilli isolated from different continents. The phylogenetic diversity analysis was performed using the combination of 16S rRNA gene sequencing, ITS-PCR, ITS-PCR-RFLP, and M13 RAPD-PCR. The analysis revealed that Bacillus subtilis U170B and B. subtilis U146A isolated from iru were the closest relatives of strains belonging to the phylogeny of B. subtilis sensu stricto and were related to other bacilli isolated from different continents that had functional benefits. The two isolated species exhibited resistance to acidic pH (pH 2.0). The survival rates of B. subtilis U170B, B. subtilis U146A, and B. clausii UBBC-07 (commercial probiotic strain) cultured at pH 2.0 for 3 h were 33.45, 12.44, and 9.53%, respectively. The strains were highly tolerant to bile salts [0.3% (w/v)]. B. subtilis U170B exhibited the highest cell viability (43.45%) when cultured for 3 h in the presence of bile salts, followed by B. subtilis U146A (25%) and B. clausii UBBC-07 (18.94%). B. subtilis U170B and B. subtilis U146A did not exhibit haemolytic activity and were susceptible to different antibiotics. Additionally, these two strains exhibited weak antagonistic activity against B. cereus. The diverse wild strains of B. subtilis can be used as a safe multifunctional starter culture for the industrial production of condiments with health benefits.

• KSBB Journal
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• v.30 no.3
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• pp.109-113
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• 2015

Current drying and encapsulation methods for probiotics manufacturing are complicate and cost-burdened processes. The aim of this study was to develop a simple ingredient mixture to make probiotic granules via one-step process, providing not only a cryoprotective effect during freezing and drying but also high survival ratio in gastrointestinal tract. As cryoprotectans, commercially available ingredients including skim milk, monosaccharide (trehalose or glycerin), maltodextrins (with low or high degree of equivalents) were used. Their cryoprotective effect during lyophilization and survival ratios in artificial gastric juice and bile salt were measured against 3 strains of lactic acid bacteria (LAB) (Lactobacillus plantarum, Lb. brevis, and Lactococcus lactis). As results, 3 mixtures with different compositions showed a cryprotective effect on LAB tested and the best compostion was dependant upon LAB; skim milk 10%, trehalose 15%, glycerin 0.5%, and NaCl 1% was for Lb. plantarum and Lc. lactis, and maltodextrin 10% instead of skim milk was for Lb. brevis. In addition, those mixtures showed similar survival effect on LAB tested. These results demonstrate that skim milk or maltodextrins with trehalose, glycerin, and NACl can be effectively used for onestep lyophilization of LAB as an alternative method of encapsulation.

• Food Science of Animal Resources
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• v.30 no.4
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• pp.634-640
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• 2010

The principal objective of this study was to screen and select acid-tolerant Lactobacillus strains from chicken feces, feeds, and other sources. Fourty six strains evidencing acid tolerance (pH 3.5) were isolated in this study. Among them, nine strains exhibited marked immunostimulatory effects. Therefore, nine candidate strains were characterized for probiotic use. In order to evaluate macrophage activation, NO production was measured using RAW 264.7 cells. In particular, three strains (FC812, FC222, and FC113) evidenced the highest levels of NO production measured at $38.39{\pm}20.01,\;35.06{\pm}27.73$, and $33.88{\pm}15.99{\mu}M$, respectively, at a concentration of $10^{8}CFU/mL$. The majority of strains, with the exception of strain FC322, evidenced marked resistance to artificial gastric juice (pH 2.5 with 1%(w/v) pepsin). Additionally, strains FC222, FC421, FC511, and FC721 were highly resistant to artificial bile acid (0.1%(w/v) oxgall), whereas strains FC113, FC322, FC422, FC621, and FC812 were the least resistant to bile. All nine strains exerted antimicrobial effects against chickenrelated pathogens. Additionally, all nine strains were found to be resistant to several antibiotics. The isolated strains, except for strain FC322, were tentatively identified as Lactobacillus salivarius, using an API 50 CHL kit. These results demonstrate that some probiotic organisms may potentially probiotic properties, and thus may serve as an effective alternative to antibiotics in animal applications.