• Korean Journal of Organic Agriculture
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• v.27 no.1
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• pp.65-76
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• 2019

Bacillus genus are found abundantly in various sites and their secondary metabolites were used as potential agents in agriculture, notably plant growth promoting and bio-control. The objective of this study was to develop the culture conditions of GH1-13 strain including higher cell growth, stable endospore-forming and enhancement of potential agents which are related with plant growth promoting and phytopathogen suppression. The optimal carbon and nitrogen sources were determined by glucose and soy bean flour, respectively, then resulted in $7.5{\times}10^9cells/mL$, $6.8{\times}10^9\;endospore\;cells/mL$ and sporulation yield of 90% after 30 h cultivation in 500 L submerged fermenter at $37^{\circ}C$, pH 7.0. Cells and cell-free supernatant of GH1-13 strains showed the potent antifungal activity against phytopathogenic fungi of Colletotrichum gloeosporioides. It was also confirmed that indole-3-acetic acid (IAA) production of GH1-13 strain was greatly increased by addition of 0.3% tryptophan.

• Tuberculosis and Respiratory Diseases
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• v.43 no.1
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• pp.46-53
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• 1996

Background: Endotoxin or lipopolysaccharide(LPS) can prime phagocytic cells such as polymorphonuclear leukocytes, monocytes or animal peritoneal macrophages to generate increased amounts of secretory products such as oxygen free radicals and tumor necrosis factor, which play an important role in developing adult respiratory distress syndrome in gram negative sepsis. Human alveolar macrophages(HAM) are continuously exposed to various stimuli inhaled into the alveoli, and the response to LPS might be different in HAM. Therefore, we investigated the effect of LPS pre-exposure on HAM adhered to plastic surface and A549 cell(type II human alveolar epithelial cell line) monolayer. Methods: HAM were isolated from bronchoalveolar lavage fluid from normal lung of the patients with localized lung cancer and esophageal cancer. LPS was exposed to HAM for 2hrs before or after adherence to plastic surface of 24-well Linbro plate and A549 cell monolayer. And then HAM was stimulated with PMA(phorbol myristate acetate) or fMLP(N-formyl-methionylleucyl-phenylalanine). The amount of hydrogen peroxide($H_2O_2$) production in the supernatant was measured on the principle of peroxidase-dependent oxidation of phenol red by hydrogen peroxide. Results: LPS pre-exposure could not enhance $H_2O_2$ production in neither HAM adhered to plastic surface nor one to A549 cell monolayer. But LPS even in the absence of PMA or fMLP stimulation directly increased $H_2O_2$ release in HAM if added after the adherence to A549 cell monolayer. Conclusion: Endotoxin does not prime HAM, but may directly activate HAM adhered to alveolar epithelial cells. Further investagation will be necessary.

• Journal of Animal Science and Technology
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• v.49 no.5
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• pp.621-632
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• 2007

The aim of this study was to isolate and characterize bacteriocin-producing bacteria from the intestine of duck to use as probiotics for livestock. A total of 416 strains were isolated from the small intestine and cecum of ducks and 13 isolates were finally selected after determinging inhibitory activity against pathogenic indicators by spot-on-lawn method. The selected strains were identified as Lactobacillus salivarius JWS 58, Lactobacillus plantarum JWS 1354, Pediococcus pentosaceus JWS 939, 7 strains of enterococci, and 3 strains of Escherichia coli. Lact. salivarius JWS 58, Ent. faecium JWS 833, and Ped. pentosaceus JWS 939 showed a strong inhibitory activity against Listeria monocytogenes. E. coli JWS 108 inhibited the growth of E. coli and Staphylococcus aureus. Lact. salivarius JWS 58 strain survived almost 50% in pH 2.5 phosphate buffer for 2 hr. Ped. pentosaceus JWS 939 and Lact. plantarum JWS 1354 showed strong amylolytic activity. These results suggest that a combination of bacteriocins or multispecies probiotics of the selected strains has a strong potential of alternative to antibiotics in livestock production.

• Journal of Life Science
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• v.22 no.2
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• pp.259-265
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• 2012

A bacterial strain, CK214, exhibiting high motility on an LB agar (1.5%, w/v) surface was isolated from the environment. The formation of unusual agar shrinking around colonies on agar plates was observed. The strain grew on minimal media containing pure agar as a sole carbon source. The cell-free culture supernatant of CK214 generated a reduced form of sugar in the in vitro reaction with the use of pure agar as a substrate, suggesting the secretion of an agar-degrading enzyme. The CK214 strain showed swarming motility on the solid media containing a wide range of concentrations of agar (0.5, 1.0, 1.5, 2.0% w/v). Various tests, including Gram staining, API analysis, and phylogenetic analysis based on 16S rDNA sequences identified that the CK214 strain was a G(+) rod-shaped bacterium grouped in genus Paenibacillus. Electron microscopic analysis demonstrated that the P. CK214 strain is peritrichously flagellated. Through transposon random mutagenesis, several agar-degrading activity defective mutants (ADMs) were generated. These mutants will be used in the future experimentation for the study of the correlation between agar-degrading activity and motility.

• The Korean Journal of Mycology
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• v.43 no.3
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• pp.137-141
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• 2015

This study focused on isolation of wild yeasts from natural flowers and elucidation of yeast diversity. Wild yeasts were isolated from various flowers collected from mountains on the islands including Jejudo, Ulleungdo, Yokjido, and Seonyudo as well as inlands including Gyejoksan, Oseosan, Beakamsan, and Deogyusan in Korea. Isolated yeasts were identified by comparison of nucleotide sequences for polymerrase chain reaction-amplified D1/D2 region of 26S rDNA or internal transcribed spacer 1 and 2 including 5.8S rDNA using BLAST. 289 strains belonging to 134 yeast species were isolated. Cryptococcus genus strains were the most frequently isolated species among the identified yeasts. Metschnikowia reukaufii was also frequently isolated. Twenty three species including Cryptococcus aureus were overlapped between those of mountains on islands and inland. Physiological functionalities such as antioxidant activity, xanthine oxidase inhibitory activity, and tyrosinase inhibitory activity for the 289 identified yeast strains were investigated using their supernatant and cell-free extracts. The supernatants of Candida sp. 78-J-2 and Metschnikowia reukaufii SY44-6 showed antioxidant activity of 22.5%, and anti-gout xanthine oxidase inhibitory activity of 49.6%, respectively.

• Korean Journal of Microbiology
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• v.48 no.2
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• pp.163-170
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• 2012

In order to inhibit the growth of pathogens and degrade biogenic amines during the fermentation of soybean products, an isolate with antimicrobial activity against pathogens and biogenic amine-degrading property was obtained from 83 traditionally fermented soybean products. The morphological and biochemical tests and the phylogenetic relationship among 16S rRNA gene sequences indicated that the isolate named as the strain SCK B11 was most closely related to Bacillus licheniformis. The cell-free supernatant of two day cultures was active against several pathogens including Enterococcus faecalis, Listeria monocytosis, Micrococcus luteus, Pseudomonas aeruginosa, Bacillus cereus, and Staphylococcus aureus. PCR analysis was conducted to determine relatedness to antimicrobial lantibiotics and biosurfactants produced by Bacillus spp., but showed negative for the genes encoding surfactin, lichenysin, and lichenicidine. Electron microscopic observation indicated that the antimicrobial agent seemed to attack the membrane of the pathogens, leaving the ghost or shrunken cells. The strain was found to degrade histamine by 72% and tyramine by 66% in the cooked soybean containing 5.3% of biogenic amine over 10 days of fermentation time. The use of selected strain would be a potential control measure in manufacturing traditionally fermented soybean products that are difficult to control pathogens and biogenic amine levels.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.2
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• pp.125-131
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• 2015

Phenyllactic acid (PLA) which is known as antimicrobial compound can be synthesized through the reduction of phenylpyruvic acid (PPA) by lactate dehydrogenase (LDH) of lactic acid bacteria (LAB). LAB producing PLA was isolated from Korea Kimchi and identified to Lactobacillus plantarum SJ21 by 16 rRNA gene sequence analysis. Cell-free supernatant (CFS) from L. plantarum SJ21 was assessed for both the capability to produce the antimicrobial compound PLA and the antifungal activity against four fungal pathogens (Rhizoctonia solani, Aspergillus oryzae, Botrytis cinerea, and Collectotricum aculatum). PLA concentration was investigated to be 3.23mM in CFS when L. plantarum SJ21 was grown in MRS broth containing 5mM PPA for 16 h. PLA production also could be promoted by the supplement of PPA and phenylalanine in MRS broth, but inhibited by the supplement of 4-hydroxyphenylpyruvic acid and tyrosine as precursors. Antifungal activity demonstrated that all fungal pathogens were sensitive to 5% CFS (v/v) of L. plantarum SJ21 with average growth inhibitions ranging from 27.32% to 69.05% (p<0.005), in which R. solani was the most sensitive to 69.05% and followed by B. cinerea, C. aculatum, and A. oryzae. The minimum inhibitory concentration (MIC) for commercial PLA was also investigated to show the same trend in the range from $0.35mg\;mL^{-1}$ (2.11 mM) to $0.7mg\;mL^{-1}$ (4.21 mM) at pH 4.0. The inhibition ability of CFS against the pathogens was not affected by heating or protease treatment. However, pH modification in CFS to 6.5 caused an extreme reduction in their antifungal activity. These results may indicate that antifungal activities in CFS were caused by acidic compounds like PLA or organic acids rather than proteins or peptides molecules.

• Journal of Life Science
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• v.25 no.2
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• pp.214-222
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• 2015

Aeromonas hydrophila is the most common water fish pathogen and cause diseases such as hemorrhagic septicemia, dropsy, ulceration and asymptomatic septicemia. A. hydrophila secretes many extracellular products (ECPs) which contribute to effective infection, wide distribution and great adaptability to environmental changes. Crude ECPs of A. hydrophila CK257, a strain used in this study, exhibits a toxic activity to the animals including mouse, rabbit and fish. Toxic symptoms were indicated by tissue damage and skin injuries in animal. When ECPs were subcutaneously injected to animals, skin damages were observed, appearing like necrosis. Preliminary research demonstrated that the active factors are protein component. The crude ECPs were collected after ammonium sulfate precipitation of cell-free culture supernatant. ECPs were fractionated with the use gel filtration chromatography. Five ECP fractions were obtained, of which one fraction was found to be toxic to goldfish. MALDI-TOF analyses provided two interesting proteases called M35 and M28. Both M35 and M28 are known as metalloprotease. Accordingly, proteins in an active fraction exhibited caseinolytic activity. These proteins were difference of caseinolytic activity under different metallic ions. Also active fraction has elastolytic activity. These results suggested that peptidase M28 and M35 may be a candidate factor for tissue necrosis activity about infection with A. hydrophila.

• Journal of Dairy Science and Biotechnology
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• v.34 no.3
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• pp.165-172
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• 2016

Kefir, originating from Caucasus, is an acidic, alcoholic fermented milk product with little acidic taste and a creamy consistency. It is recognized in having beneficial effects infor the prevention and treatment of cancer. For example, Kefir has possesses a chemopreventative effect on carcinogenesis. There has recently been a strong focus on fermented milk foods containing a mixture of several functional organic substances and various probiotic microorganisms. Hence, the purpose of this review paper was to evaluate the scientific evidence for the effects of kefir on cancer prevention and treatment. Some of we analyzed and summarized data-relating to the effects of kefir on cancer. The cacers that kefir has an effect on are as follows: colon cancer, breast cancer, leukemia, sarcoma, skin cancer, gastric cancer. This review suggests that (1) kefir could be associated with cancer prevention, (2) kefir has beneficial effects in cancer treatment, and (3) kefir has various bioactive components including peptides, polysaccharides and sphingolipids, which contribute tofor itsthese anti-cancer properties. Furthermore, furthermore, studies were performed in order to obtain as to get the scientific evidence of kefir's anticancer activity: (1) improved protective effectiveness in vivo (human subjects or animal model), (2) isolation and identification of various bioactive components, and (3) mechanisms associated with beneficial effects.

• Tuberculosis and Respiratory Diseases
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• v.43 no.2
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• pp.210-220
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• 1996

Background : Neutrophils or monocytes separated in vitro by the adherence to plastic surface are known to be activated by surface adherence itself and subsequent experimental data might be altered by surface adherence. In the process of surface adherence, adhesion molecules have a clear role in intracellular signal pathway of cellular activation. Human alveolar macrophages(HAM) are frequently purified by the adherence procedure after bronchoalveolar lavage. But the experimental data of many reports about alveolar macrophages have ignored the possibility of adhesion-induced cellular activation. Method : Bronchoalveolar lavage was performed in the person whose lung of either side was confirmed to be normal by chest CT. With the measurement of hydrogen peroxide release from adherent HAM to plastic surface and non-adherent HAM with or without additional stimulation of phorbol myristate acetate(PMA) or N-formyl-methionyl-leucyl-phenylalanine (fMLP), we observed the effect of the adherence to plastic surface. We also evaluated the effect of various biological surfaces on adhesion-induced activation of HAM. Then, to define the intracellular pathway of signal transduction, pretreatment with cycloheximide, pertussis toxin and anti-CD11/CD18 monoclonal antibody was done and we measured hydrogen peroxide in the culture supernatant of HAM. Results : 1) The adherence itself to plastic surface directly stimulated hydrogen peroxide release from human alveolar macrophages and chemical stimuli such as phorbol myristate acetate(PMA) or N-formyl-methionyl-leucyl-phenylalanine(fMLP) colud not increase hydrogen peroxide release in these adherent macrophages which is already activated. 2) PMA activated human alveolar macrophages irrespective of the state of adhesion. However, fMLP stimulated the release of hydrogen peroxide from the adherent macrophages, but not from the non-adherent macrophages. 3) HAM adherent to A549 cell(type II alveolar epithelium-like human cell line) monolayer released more hydrogen peroxide in response to both PMA and fMLP. This adherence-dependent effect of fMLP was blocked by pretreatment of macrophages with cycloheximide, pertussis toxin and anti-CD18 monoclonal antibody, Conclusion : These results suggest that the stimulatory effect of PMA and fMLP can not be found in adherent macrophage because of the activation of human alveolar macrophage by the adherence to plastic surface and the cells adhered to biologic surface such as alveolar epithelial cells are appropriately responsive to these stimuli. It is also likely that the effect of fMLP on the adherent macrophage requires new protein synthesis via G protein pathway and is dependent on the adhesion between alveolar macrophages and alveolar epithelial cells by virtue of CD11/CD18 adhesion molecules.