• Korean Journal of Microbiology
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• v.45 no.2
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• pp.177-184
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• 2009

Three hundred lactic acid bacteria isolated from human feces were studied their probiotic characters to develop potential probiotics. The properties were tested on the basis of guideline for probiotic selection protocol such as tolerance for acid or bile salt, thermal stability, antimicrobial, anticancer cell, and antiviral activity. Strain Miny-148 was selected as a potential probiotic bacterium which showed resistance to low pH, bile salts and thermal stability. On the basis of fatty acid profiles and 16S rDNA sequences analysis, the strain was identified as Lactobacillus pentosus (similarity 99.9%). The strain, L. pentosus Miny-148, showed broad antimicrobial spectrum against E. coli O157:H7, Shigella flexneri, Bacillus anthracis, Staphylococcus aureus, E. coli, Vibrio cholerae, V. vulnificus, Salmonella typhimurium, and Methicillin-resistant S. aureus (MRSA). Cell-free culture supernatant of the strain also inhibited against the growth of HT-29 colon cancer cell and transmissible gastroenterits virus.

• Journal of Microbiology and Biotechnology
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• v.26 no.11
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• pp.1863-1870
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• 2016

Antimicrobial peptides/proteins (AMPs) are present in all types of organisms, from microbes and plants to vertebrates and invertebrates such as insects. The grasshopper Oxya chinensis sinuosa is an insect species that is widely consumed around the world for its broad medicinal value. However, the lack of available genetic information for this species is an obstacle to understanding the full potential of its AMPs. Analysis of the O. chinensis sinuosa transcriptome and expression profile is essential for extending the available genetic information resources. In this study, we determined the whole-body transcriptome of O. chinensis sinuosa and analyzed the potential AMPs induced by bacterial immunization. A high-throughput RNA-Seq approach generated 94,348 contigs and 66,555 unigenes. Of these unigenes, 36,032 (54.14%) matched known proteins in the NCBI database in a BLAST search. Functional analysis demonstrated that 38,219 unigenes were clustered into 5,499 gene ontology terms. In addition, 26 cDNAs encoding novel AMPs were identified by an in silico approach using public databases. Our transcriptome dataset and AMP profile greatly improve our understanding of O. chinensis sinuosa genetics and provide a huge number of gene sequences for further study, including genes of known importance and genes of unknown function.

• Fisheries and Aquatic Sciences
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• v.4 no.2
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• pp.75-83
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• 2001

This study is to investigate biochemical compositions of two species of marine microalgae, Chlorella ellipsoidea of Chlorophyta and Tetraselmis suecica of Prasinophyta, and to assess their potential antimicrobial activities. Crude protein, lipid and carbohydrate for C. ellipsoidea were $43.15\%$, $12.63\%$ and $13.09\%$, respectively, and those for T. suecica were $44.95\%$, $4.80\%$ and $24.05\%$, respectively. The major amino acids of the two micro algae were aspartic acid, glutamic acid, glycine, alanine, valine, leucine, lysine and proline, and no significant difference between the amino acid compositions of both micro algae was observed. The major sugars for both microalgae were glucose, galactose and mannose, and glucose contents showed the highest level, $58.70\%$ for C. ellipsoidea and$57.86\%$ for T. suecica. The major mineral contents of both micro algae for 100g were Ca (3,114mg in C. ellipoidea and 3,389mg in T. suecica) and followed by Na (2,881mg), K (548mg) and Mg (545mg) for C. ellipsoidea and Na (1,832 mg), Mg (1,510mg) and K (548mg) for T. suecica. In the content of ATP-related compound, hypoxanthine in C. ellipsoidea and IMP in T. suecica were absolutely dominant compounds. The highest content of fatty acid in C. ellipsoidea was 20:4, $27.15\%$ and that in T. suecica was 18:3 (w-6), $18.10\%$. In case of physiologically important polyunsaturated fatty acids like eicosapentaenoic acid (20: 5) and docosahexaenoic acid (22: 6), both microalgae possessed just trace amounts but was rich in arachidonic acid (20: 4). Vitamin content in both microalgae was significantly high in choline and inositol. In antimicrobial activity by water- and fat-soluble fraction of the micro algae, hexane extract in the fat-soluble fraction of C. elliposidea inhibited the growth of Bacillus subtilis by $96\%$ bactericidal activity and tetrachlorocarbon extract of T. suecica indicated relatively excellent antimicrobial activity $(81\%\;bactericidal\;activity)$ against Escherichia coli. Hot water extract among water-soluble fraction of both micro algae almost suppressed the growth of Staphylococcus aureus by $96\%$ bactericidal activity.

• Korean Journal of Food Science and Technology
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• v.48 no.3
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• pp.241-246
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• 2016

The object of this study was to develop an alternative way to treat human skin pathogens using marine algae. During this study, we observed that the ethanolic extract of the edible brown algae [Sargassum serratifolium (C. Agardh) C. Agardh] exhibited potential antimicrobial activity against pathogenic commensal bacteria related with acne vulgaris (Propionibacterium acnes, Staphylococcus epidermidis, Staphylococcus aureus and Pseudomonas aeruginosa), and Candida albicans which causes cutaneous candidiasis. Among the solvent-soluble fractions from the ethanolic extract, a hexane-soluble fraction showed the strongest antimicrobial activity against all tested human skin pathogens with MIC values ranging from 32 to $512{\mu}g/mL$. In addition, the hexane fraction exhibited a synergistic antimicrobial activity with commercial antibiotics used in the treatment of acne vulgaris or cutaneous candidiasis. Thus, this study suggests that S. serratifolium extract could be a potential source of natural antimicrobial agents or a pharmaceutical component against human skin pathogens.

• Journal of Microbiology and Biotechnology
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• v.27 no.4
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• pp.731-738
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• 2017

A novel approach to synthesize silver nanoparticles (AgNPs) using leaf extract of Canna edulis Ker-Gawl. (CELE) under ambient conditions is reported here. The as-prepared AgNPs were analyzed by UV-visible spectroscopy, transmission emission microscopy, X-ray diffraction, Fourier transform-infrared spectroscopy, energy-dispersive analysis of X-ray spectroscopy, zeta potential, and dynamic light scattering. The AgNPs showed excellent antimicrobial activity against various pathogens, including bacteria and various fungi. The biocompatibility of the AgNPs was analyzed in the L929 cell line using NRU and MTT assays. Acridine orange/ethidium bromide staining was used to determine whether the AgNPs had necrotic or apoptotic effects on L929 cells. The concentration of AgNPs required for 50% inhibition of growth of mammalian cells is far more than that required for inhibition of pathogenic microorganisms. Thus, CELE is a candidate for the eco-friendly, clean, cost-effective, and nontoxic synthesis of AgNPs.

• International Journal of Advanced Culture Technology
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• v.8 no.1
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• pp.226-235
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• 2020

In this paper, we present to evaluate physiological activity of Robinia pseudo-acacia leaf and its skin penetration using liposome and cell penetrating peptide. After extraction with Robinia pseudo-acacia leaf using the distilled water and supercritical, various physiological activities were examined. In antioxidants experiments, the total concentration of polyphenol compounds was determined to be 56.88 mg/g in hydrothermal extract, 45.07 mg/g in supercritical extract. The DPPH radical scavenging ability at 1,000 ㎍/mL was 33.97% in supercritical extract. The scavenging effect on SOD experiment at 500 ㎍/mL was 76.41% in supercritical extract. In the antimicrobial experiments, the hydrothermal extract had no effect, but supercritical extract represented maximum clear zone of 14.00 mm in Staphylococcus aureus strain. Liposome containing the RSE (Robinia pseudo-acacia leaf supercritical extract) reduced particle size and stabilized zeta potential. In the epidermal permeability experiment, it was confirmed that the permeation of liposome containing the RSE and cell penetrating peptides was remarkable.

• Korean Journal of Pharmacognosy
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• v.42 no.4
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• pp.336-340
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• 2011

The aim of this study was to investigate the possible utilization of Zanthoxylum schinifolium as a source of antimicrobial agents. The antimicrobial effects of Zanthoxylum schinifolium extracts were investigated against Acinetobacter baumannii, which is a multi-drug resistant pathogen, and 5 other pathogenic microorganisms. The hexane extract of Zanthoxylum schinifolium was more effective than the ethyl acetate, n-butanol and methanol extracts which were active against Acinetobacter baumannii 25, with minimum inhibitory concentrations(MIC) ranging from 0.8 mg/ml to 1.6 mg/ml. Tetracycline had no effect on Acinetobacter baumanniii. The hexane extract was highly active against Candida albicans IFO 6258, with an MIC of 1.5 mg/ml. In contrast, the ethyl acetate, n-butanol and methanol extracts showed no activity against the 5 pathogenic microorganisms. Furthermore, a combination of hexane extract and ethyl acetate extract was significantly more active against the 5 Acinetobacter baumannii strains than n-butanol and methanol. These results suggest that Zanthoxylum schinifolium extracts have great potential as antimicrobial compounds against multi-drug resistant pathogens, and further studies are warranted.

• Korean Journal of Veterinary Research
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• v.33 no.1
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• pp.53-60
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• 1993

Anaerobic bacteria are suggested to be potential source for new antibiotics. In order to search for antibiotics from domestic origin, we collected 800 soil samples across Korean locations and could isolate as many as 989 anaerobic strains. Among them 10, strains were found to have good producing capacity of antibiotics. An anaerobe was finally selected due to secreting antibiotics having high antimicrobial activity towards multiple resistant microorganism(E coli JM 83) transformed by genetic engineering technique. Its morphological, physiological and biochemical charateristics were investigated, together with antimicrobial spectrum therefrom. On antimicrobial spectrum study, substance secreted from this strain, had no activities to fungus and yeast. The selected strain showed G(+) and coccal shape, on Gram, staining and electron scanning microscopy, respectively. Biochemically this strain utilized glucose, fructose lactose, sucrose, but did not arabinose, cellulose, rhamnose, sorbitol, trehalose, mannitol. Catalase test showed negative property. Optimal growth temperature was $37^{\circ}C$. The results obtained above suggest this strain Streptococcus faecium subspp. and we named it Streptococcus sp. An-21-1.

• Journal of the Korean Applied Science and Technology
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• v.37 no.2
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• pp.279-286
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• 2020

Natural extracts were isolated from 20 kinds of medicinal plants that have been traditionally widely used in Korea to develop treatments for dental caries. Medicinal plants showing antibacterial activity against a cariogenic bacterium, Streptococcus sobrinus KCOM 1157 were investigated. The natural extracts of Glycyrrhiza uralensis, Sophora flavescens, Coptis Chinensis, Mentha arvensis, Pinus densiflora, Spirodela polyrhiza showed antimicrobial activities against S. sobrinus KCOM 1157. The extracts of Pinus densiflora, Sophora flavescens, Coptis Chinensis among these medical herbs showed significant antimicrobial activity. These results suggested that the natural products of Pinus densiflora, Sophora flavescens, Coptis Chinensis could be the potential source of anticariogenic agent against dental pathogens including S. sobrinus.

• Journal of Microbiology and Biotechnology
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• v.30 no.10
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• pp.1443-1457
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• 2020

The emergence and spread of antimicrobial resistance in pathogenic bacteria of fish and shellfish have caused serious concerns in the aquaculture industry, owing to the potential health risks to humans and animals. Among these bacteria, Aeromonas salmonicida, which is one of the most important primary pathogens in salmonids, is responsible for significant economic losses in the global aquaculture industry, especially in salmonid farming because of its severe infectivity and acquisition of antimicrobial resistance. Therefore, interest in the use of alternative approaches to prevent and control A. salmonicida infections has increased in recent years, and several applications of bacteriophages (phages) have provided promising results. For several decades, A. salmonicida and phages infecting this fish pathogen have been thoroughly investigated in various research areas including aquaculture. The general overview of phage usage to control bacterial diseases in aquaculture, including the general advantages of this strategy, has been clearly described in previous reviews. Therefore, this review specifically focuses on providing insights into the phages infecting A. salmonicida, from basic research to biotechnological application in aquaculture, as well as recent advances in the study of A. salmonicida.