• Journal of Mushroom
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• v.14 no.4
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• pp.162-167
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• 2016

Lactic acid bacteria (LAB) producing phenyllactic acid (PLA), which is known as antimicrobial compound, was isolated from button mushroom bed and the isolated LAB was identified to Lactobacillus casei by 16 rRNA gene sequence analysis. Cell-free supernatant (CFS) from L. casei was assessed for both the capability to produce the antimicrobial compound PLA and the antifungal activity against three fungal pathogens (Rhizoctonia solani, Botrytis cinerea, and Collectotricum aculatum). PLA concentration was investigated to be 3.23 mM in CFS when L. casei was grown in MRS broth containing 5 mM phenylpyruvic acid as precursor for 16 h. Antifungal activity demonstrated that all fungal pathogens were sensitive to 5% CFS (v/v) of L. casei with average growth inhibitions ranging from 34.58% to 65.15% (p < 0.005), in which R. solani was the most sensitive to 65.15% and followed by C. aculatum, and B. cinerea. The minimum inhibitory concentration (MIC) for commercial PLA was also investigated to show the same trend in the range of 0.35 mg mL-1 (2.11 mM) to 0.7 mg mL-1 (4.21 mM) at pH 4.0. The inhibition ability of CFS against the pathogens were not affected by the heating or protease treatment. However, pH modification in CFS to 6.5 resulted in an extreme reduction in their antifungal activity. These results may indicate that antifungal activities in CFS was caused by acidic compounds like PLA or organic acids rather than protein or peptide molecules.

• Biomedical Science Letters
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• v.24 no.1
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• pp.30-34
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• 2018

Silver (Ag) has been widely used in commercial products and medical fields since ancient times because of its antibacterial effect. It is harmless and non-toxic to the human body. For this reason, recent research has actively evaluated antimicrobial activity using silver (Ag). In this study, we investigated the inhibitory effect of a silver-based compound, silver phosphate ($Ag_3PO_4$) on the growth of Staphylococcus aureus and the activation of human immunity. First, the inhibitory effect of $Ag_3PO_4$ on the growth of Staphylococcus aureus was confirmed by a growth curve and a colonyounting method. As a result, the growth inhibitory effect increased as the concentration of $Ag_3PO_4$ increased. Specifically, treatment with $5{\mu}g/mL$ of $Ag_3PO_4$ resulted in no bacteria growth, and the colony-counting method showed a remarkable inhibition. In addition, the expression of cytokine IL-8 by $Ag_3PO_4$ was examined to investigate the cellular immune system activation by $Ag_3PO_4$. After pretreatment of Staphylococcus aureus for 1 hour with $50{\mu}g/mL$ $Ag_3PO_4$, an increased IL-8 mRNA expression resulted. In cells treated with $Ag_3PO_4$, we found that the expression of IL-8 was enhanced in a time-dependent fashion compared to non-treated cells. These results indicate that $Ag_3PO_4$ induces antimicrobial activity against Staphylococcus aureus and activates human immunity. These results are expected to contribute to the future study of the mechanism of silver (Ag) and silver-based compounds in relation to antibacterial activity.

• Journal of agricultural medicine and community health
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• v.18 no.1
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• pp.55-63
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• 1993

A simultaneous determination method by HPLC for egg-residues sulfamerazine, sulfamethazine, sulfadimethoxine, furazolidone and zoalene was assesed. The drugs were extracted by dechloromethane, The extract after solvent evaporation, is partitioning in hex ane/water and back-partitioning in dechloromethane and analysis by HPLC. The average recovery rates of the above microbials from the egg spiked standard solution were approximately 81.2%, 87.6%, 92.5%. 86.1% and 79.3% respectively. The limit of detection of sulfamerazine. sulfamethazine and sulfamethoxine were in the levels of 0.2ppb, furazolidone and zoalene 0.5ppb respectively. According to this method 84 commercial eggs were examined. Sulfamethanzine was detected at levels of 0.005-0.008ppm in 3 eggs. Sulfadimethoxine was detected at levels of 0.012-0.019ppm in 4 eggs. No sulfamerazine, furazolidone and zoalene was detected in every samples. The residues of antimicrobial agent were safety level as food generally.

• Korean Journal of Veterinary Research
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• v.55 no.2
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• pp.81-88
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• 2015

This study was conducted to isolate lactic acid bacteria (LAB) from dog intestine and identify potential probiotic strains for canine use. One hundred and one LAB were isolated from feces of 20 healthy dogs. Acid, bile, and heat resistance along with adherence to Caco-2 cells and antimicrobial activity against pathogens were examined. To analyze immunomodulative effects, the production of nitric oxide (NO), TNF-${\alpha}$, and IL-$1{\beta}$ was measured using RAW 264.7 macrophages. Additionally, RAW BLUE cells were used to evaluate nuclear factor-${\kappa}B$ (NF-${\kappa}B$) generation. Ultimately, three strains were selected as canine probiotics and identified as Lactobacillus reuteri L10, Enterococcus faecium S33, and Bifidobacterium longum B3 by 16S rRNA sequence analysis. The L10 and S33 strains showed tolerance to pH 2.5 for 2 h, 1.0% Oxgall for 2 h, and $60^{\circ}C$ for 5 min. These strains also had strong antimicrobial activity against Escherichia coli KCTC 1682, Salmonella Enteritidis KCCM 12021, Staphylococcus aureus KCTC 1621, and Listeria monocytogenes KCTC 3569. All three strains exerted better immunomodulatory effects than Lactobacillus rhamnosus GG (LGG), a well-known commercial immunomodulatory strain, based on NO, NF-${\kappa}B$, IL-$1{\beta}$, and TNF-${\alpha}$ production. These results suggested that the three selected strains could serve as canine probiotics.

• Preventive Nutrition and Food Science
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• v.22 no.2
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• pp.124-130
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• 2017

This paper describes in detail proximate composition, nutritional profile, phytochemical constituents, antioxidant activities, antimicrobial potential, and antihemolytic activity (towards human erythrocytes) of various fractions of wild Ganoderma lucidum. Proximate analysis established that wild G. lucidum comprises about $87.02{\pm}5.45%$ of moisture, and the remaining part is a rich source of proteins ($8.59{\pm}0.37%$), crude fiber ($54.21{\pm}1.2%$), and carbohydrate (35.16%) with smaller fat content (3.33 %). Similarly, phytochemical screening revealed the presence of flavonoids ($217.51{\pm}0.30mg/g$), ascorbic acid ($116{\pm}7.32mg/g$), phenolics ($360.72{\pm}34.07mg/g$), ${\beta}$-carotenes ($0.42{\pm}0.04{\mu}g/g$), and lycopene ($0.05{\pm}0.00{\mu}g/g$). Extracts of wild G. lucidum in various solvents provided first line protection against Escherichia coli and Pasteurella multocida in the order of ethyl acetate> ethanol> methanol> n-hexane> water. Furthermore, aqueous and methanolic extracts of wild G. lucidum were found to be safe towards human erythrocytes. Overall, wild mushroom (G. lucidum) was found to be a good source of dietary supplements, antimicrobial and antioxidant agents in the pursuance of its commercial utilization in food and pharmaceutical industries.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.8
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• pp.1130-1135
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• 2005

The objective of this study was to evaluate the antimicrobial activity of four herb extracts from lavender, patchouli, rosemary and eucalyptus possibly used as food preservatives. Minimum inhibitory concentration of France rosemary extracts was 29.1 mg/mL against C. albicans ATCC 10231 and 14.5 mg/mL against B. subtilis ATCC 6613 and E. coli ATCC 25922. Both of France rosemary and American lavender herbal extracts were thermally stable between 40$^{\circ}C$ and 121$^{\circ}C$ and were stable at only neutral pH. Microbial growth was repressed by adding 2.9 mg of a commercial herbal extracts in 20 mL liquid medium with France rosemary extracts and American lavender extracts.

• Journal of Microbiology and Biotechnology
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• v.32 no.9
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• pp.1195-1208
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• 2022

Silver nanoparticles (AgNPs) have potential applications in medicine, photocatalysis, agriculture, and cosmetic fields due to their unique physicochemical properties and strong antimicrobial activity. Here, AgNPs were synthesized using actinobacterial SL19 strain, isolated from acidic forest soil in Poland, and confirmed by UV-vis and FTIR spectroscopy, TEM, and zeta potential analysis. The AgNPs were polydispersed, stable, spherical, and small, with an average size of 23 nm. The FTIR study revealed the presence of bonds characteristic of proteins that cover nanoparticles. These proteins were then studied by using liquid chromatography with tandem mass spectrometry (LC-MS/MS) and identified with the highest similarity to hypothetical protein and porin with molecular masses equal to 41 and 38 kDa, respectively. Our AgNPs exhibited remarkable antibacterial activity against Escherichia coli and Pseudomonas aeruginosa. The combined, synergistic action of these synthesized AgNPs with commercial antibiotics (ampicillin, kanamycin, streptomycin, and tetracycline) enabled dose reductions in both components and increased their antimicrobial efficacy, especially in the case of streptomycin and tetracycline. Furthermore, the in vitro activity of the AgNPs on human cancer cell lines (MCF-7, A375, A549, and HepG2) showed cancer-specific sensitivity, while the genotoxic activity was evaluated by Ames assay, which revealed a lack of mutagenicity on the part of nanoparticles in Salmonella Typhimurium TA98 strain. We also studied the impact of the AgNPs on the catalytic and photocatalytic degradation of methyl orange (MO). The decomposition of MO was observed by a decrease in intensity of absorbance within time. The results of our study proved the easy, fast, and efficient synthesis of AgNPs using acidophilic actinomycete SL19 strain and demonstrated the remarkable potential of these AgNPs as anticancer and antibacterial agents. However, the properties and activity of such particles can vary by biosynthesized batch.

• Microbiology and Biotechnology Letters
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• v.37 no.2
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• pp.133-139
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• 2009

Yam (Dioscorea batatas Decne) has been recognized as healthy food due to its various biological activities, such as anti-obesity, anti-constipation, anti-proliferation, anti-mutagenic activity, and decrease of blood glucose and cholesterol level. In this study, the methanol extract and its organic solvent fractions were prepared from dried Dioscorea batatas Decne, and their antimicrobial, antithrombin, and antioxidant activity were evaluated, respectively. The 66.7% of methanol extract was fractioned into water residue, and most of total-polyphenol/total-flavonoids were found in ethylacetate fraction. This ethylacetate fraction at $500\;{\mu}g/disc$ concentration showed strong antibacterial activity against gram-negative and gram-positive bacteria, except Staphylococcus aureus. Antifungal activity was not observed in methanol extract and its fractions. But, strong antithrombin activity was found in methanol extract. At 4.8 mg/mL concentration, thrombin time was 99.5 sec, which is coincides with 30% activity of aspirin, a commercial available antithrombosis agent. The ethylacetate fraction showed strong DPPH scavenging activity ($IC_{50}$ of $80.5\;{\mu}g/mL$), compared to vitamin C ($IC_{50}$ of $15.2\;{\mu}g/mL$). Also, the ethylacetate fraction showed strong SOD-like activity and reducing power, which are coincide with 43% of vitamin C and 82.7% of butylated hydroxytoluene activity, respectively.

• Korean Journal of Microbiology
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• v.50 no.3
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• pp.216-222
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• 2014

their survival rates could be affected by various factors such as diet, stress, senescence, and antibiotics. This study was performed to evaluate the influence of various spices (garlic, ginger, scallion, onion, Chungyang red pepper, and red pepper) which have antimicrobial properties and used frequently in Korean diet, and propolis on probiotics isolated from Koreans. As a result, most Korean probiotic strains were resistant to all spices tested and propolis, and the growth rates of some Korean probiotic strains (Bifidobacterium lactis, Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus rhamnosus, Streptococcus thermophiles) were even increased by specific spices or propolis. But on the other hand, the growth rates of most of european probiotic strains were reduced by various spices or propolis, and the growth rates of a few european probiotic strains (L. helveticus, S. thermophiles) were greatly decreased in the presence of specific spices. Likewise, all commercial probiotic products including Korean probiotic strains were rarely affected by spices tested. However, european probiotic product tended to be greatly reduced by garlic, onion, scallion, and propolis. Therefore, these results indicate that probiotic strains isolated from Korean have the strong viability and resistance to various spices with antimicrobial properties, so that they might be appropriate for Korean intestine.

• Korean Journal of Food Science and Technology
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• v.51 no.2
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• pp.114-119
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• 2019

Seven antimicrobial agents known to be effective in inhibiting the growth of lactic acid bacteria were applied to ensure the microbial safety of low-salted squid and myungran jeotgal with 4-6% salinity. These agents reduced the salt content by 50% compared with the conventional Jeotgal. Lactic acid bacteria such as Lactobacillus sp., Streptococcus sp., and Pediococcus sp. were commonly found to account for 80% of microbial organisms, and yeast and fungi were observed in squid and myungran jeotgal, respectively. The total bacterial counts in squid and myungran jeotgal showed 94.20 and 90.87% reduction after the addition of 0.5% (w/w) glycine. The microbial counts in squid and myungran jeotgal decreased $10^1-10^2CFU/g$ when compared with the control after 21 days at $10^{\circ}C$. Glycine was found to be an effective commercial antimicrobial agent that can be used to control bacterial count in low-salted Jeotgal without affecting sensory qualities such as overall taste and flavor.