• Research in Plant Disease
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• v.21 no.4
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• pp.297-308
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• 2015

In order to control seed-borne diseases, we obtained extracts from commercial fermented food products of Kimchi, Gochujang, Doenjang, Ganjang and Makgeolli and their suppressive effects against seed-borne diseases were studied. In addition, the suppressive effects of bacterial strains isolated from the fermented foods were screened in vitro and in vivo. Among fifty food extracts, twenty food-extracts suppressed more than 92% incidence of seedling rots in vitro and seven food extracts increased 58.3-66.8% of healthy seedling in the greenhouse. Among 218 isolates from the fermented foods, 29 isolates showing high antifungal activity against seven seed-borne fungal pathogens were selected. Among 29 isolates, 13 isolates significantly reduced seedling rot and increased healthy seedlings. Sixteen isolates with high antifungal activity and suppressive effect against sesame seedling rots were identified by 16S rRNA sequencing. Fourteen of sixteen isolates were identified as Bacillus spp. and the other two isolates from Makgeolli were identified as Saccharomyces cerevisiae. It was confirmed that B. amyloliquifaciens was majority in the effective bacterial population of Korean fermented foods. In addition, when the bioformulations of the two selected effective microorganisms, B. amyloliquifacien Gcj2-1 and B. amyloliquifacien Gcj3-1, were prepared in powder forms using bentonite, kaolin, talc and zeolite, talc- and kaolin-bioformulation showed high control efficacy against sesame seed-borne disease, followed by zeolite-bioformulation. Meanwhile control efficacy of each bentonite-bioformulation of B. amyloliquifacien Gcj2-1 and B. amyloliquifacien Gcj3-1 was lower than that of bacterial suspension of them. It was found that the selected effective microorganisms from Korean fermented foods were effective for controlling seed-borne diseases of sesame in vitro and in the greenhouse. We think that Korean fermented food extracts and useful microorganisms isolated from the extract can be used as bio-control agents for suppressing sesame seed-borne diseases based on above described results.

• Journal of the Mineralogical Society of Korea
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• v.26 no.4
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• pp.219-228
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• 2013

To understand characteristics of biogeochemical corrosion for the metal canisters that usually contain the radioactive wastes for a long-term period below the ground, some metal materials consisting of cast iron and copper were reacted for 3 months with D. desulfuricans, a sulfate-reducing bacterium, under a reducing condition. During the experiment, concentrations of dissolved metal ions were periodically measured, and then metal specimen and surface secondary products were examined using the electron microscopy to know the chemical and mineralogical changes of the original metal samples. The metal corrosion was not noticeable at the absence of D. desulfuricans, but it was relatively greater at the presence of the bacterium. In our experiment, darkish metal sulfides such as mackinawite and copper sulfide were the final products of biogeochemical metal corrosion, and they were easily scaled off the original specimen and suspended as colloids. For the copper specimen, in particular, there appeared an accelerated corrosion of copper in the presence of dissolved iron and bacteria in solution, probably due to a weakening of copper-copper binding caused by a growth of other phase, iron sulfide, on the copper surface.

• Korean Journal of Microbiology
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• v.55 no.1
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• pp.46-51
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• 2019

This study was carried out to evaluate antimicrobial effects of a mixture of resin fractionated ethanol extract of Eucalyptus globulus, Yucca recurvifolia, and tea tree (Melaleuca alternifolia). The plant fraction mixture showed low minimum inhibitory concentration (0.24~3.32 mg/ml) against several bacteria and yeast that usually used as the target skin microbes in a cosmetic industry, and it was more effective than antibiotics, triclosan and ampicillin. In a time-kill assay the plant fraction mixture reduced more than 92% of microbial populations during 4 h, and significantly increased leakage of nucleotides from all microorganisms tested. Antimicrobial effect of the plant fraction mixture was not affected by divalent cation ($Mg^{2+}$ and $Ca^{2+}$). These results suggest that the fraction mixture of ethanol extracts of E. globulus, Y. recurvifolia, and M. alternifolia may be utilized as an efficient preservative in cosmetics to prevent contamination by human skin microbes.

• Journal of Korean Society on Water Environment
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• v.39 no.2
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• pp.181-193
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• 2023

Distribution changes in microalgae communities were studied in the Nakdonggang River at two sampling stations (St.1 Gyeongcheongyo Bridge (GB) and St.2 Daedong Wharf (DW)) at monthly intervals from January 2021 to November 2021. A total of 83 taxa included 82 species, 1 forma, belonging to 49 genera, 32 families, 21 orders, and 8 classes. The most important groups were Bacillariophyta and Chlorophyta. The number of species ranged from 5 to 24 in GB, and from 9 to 21 taxa in DW. The contribution of Bacillariophyta to the total species richness was the highest during all survey periods, and Chlorophyta yielded the next highest value in the study area. The dominant taxa were Aulacoseira ambigua, A. ambigua f. japonica, and Ulnaria acus in this study. Cluster analysis and non-metric multidimensional scaling (nMDS) analysis based on Bray- Curtis similarity identified 4 major groups, which corresponded to microalgae assemblages and their characteristic species. Correlation was analyzed through the CCA analysis. It was found that there was a correlation between the microalgae and environmental factors. It was revealed that the divided groups were distinguished because of the differences by the survey period. Therefore, seasonal change was judged as a major factor affecting the distribution of microalgae communities.

• Journal of Life Science
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• v.28 no.7
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• pp.827-834
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• 2018

In this study, the biological activities of aqueous, ethanol, and methanol extracts of larvae of the edible insect Protaetia brevitarsis seulensis, fermented using several kinds of microorganisms, were tested in in vitro experimental models. Six effective microorganisms were used for fermentation, namely Lactobacillus plantarum JBMI F3, Lactobacillus plantarum JBMI F5, Lactobacillus gasseri Ba9, Aspergillus kawachii KCCM 32819, Saccharomyces cerevisiae KACC 93023, and Bacillus subtilis KACC 91157. Biological activities (${\alpha},{\alpha}^{\prime}-diphenyl-{\beta}-picrylhydrazyl$ [DPPH] free radical scavenging activity, reducing power, and fibrinolytic activity), and biochemical properties (phenolic compounds and flavonoids) were examined in aqueous, ethanol, and methanol extracts from P. brevitarsis seulensis powder and fermented P. brevitarsis seulensis powder. The total phenolic compounds and flavonoid contents were highest in the aqueous extract of B. subtilis-fermented P. brevitarsis seulensis powder. DPPH radical scavenging activity and reducing power were stronger in the fermented group than the nonfermented group. Fibrinolytic activity were highest in the extract from B. subtilis-fermented P. brevitarsis seulensis powder. The ${\alpha}-amylase$ activity in starch was higher in the fermented group than the nonfermented group, but there was no significant difference. These results provide basic data to understand the biological activities of bioactive materials derived from fermented P. brevitarsis seulensis larvae for the development of functional foods.

• Journal of Food Hygiene and Safety
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• v.18 no.4
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• pp.189-194
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• 2003

Approved chemical preservatives have been widely used to preserve foods and increase their shelf life. There are increasing demends of the partial or complete removal of chemical preservatives from foods vecause of adverse health effect of chemicals. In this study, the possibility of natural antimicrobial compounds, Korean propolis as food preservatives are investigated. Propolis samples were extracted on various concentration of ethanol. Propolis extracts extracted with 100% ethanol showed the highest inhibitory effect aginst food spoilage microorganisms. The 100% ethanol extracts of propolis were selected and the antimicrobial activites of 100% ethanol extracts of proplis against several food spoilage microorganisms were examined. Bacillus subtilis, Micrococcus luteus, Escherichia coli, Staphylcoccus aureus, Bacillus cereus, Shigella sonnei, Salmonella choleraesuis, Erwinia rhapontici, and Vibrio parahaemolyticus as food poisoning microorganisms were chosen for the examination. The Propolis extracts had antimicrobial activity against food spoilage microorganisms. When the microorganisms were treated with propolis extracts, the population of food spolige microorganisms were decreased by 1~9 log.

• Food Science of Animal Resources
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• v.31 no.1
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• pp.122-128
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• 2011

This study was conducted to investigate the antioxidant effects, total plate count (TPC), and residual nitrite content of emulsified sausage with added mugwort during cold storage. The sausages were of five types: nothing added (control), mugwort powder added (T1), mugwort juice added (T2), mugwort ethanol extract added (T3), and mugwort hot water extract added (T4). Each sausage type was tested in triplicate and assigned to one of five storage periods: 0, 1, 2, 3, or 4 wk. As storage time increased, the presence of mugwort resulted in decreased pH, residual nitrite content, and meat color (CIE $L^*$ and $b^*$) and increased thiobarbituric acid reactive substance (TBARS) and TPC values. Values for pH, TBARS, residual nitrite, and TPC decreased significantly after adding mugwort compared with the control (p<0.05). Among all treatments, T3 was significantly (p<0.05) more effective in delaying lipid oxidation and microbial activity. The CIE $L^*$ and $b^*$ decreased significantly with the addition of mugwort relative to the control. In conclusion, the results demonstrate that adding an ethanol extract of mugwort (T3) to emulsified sausages tended to improve antioxidant and antimicrobial effects and residual nitrite content during storage compared to the other treatment groups.

• Food Science and Preservation
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• v.13 no.3
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• pp.304-309
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• 2006

In order to examine the antimicrobial effect on dairy processing facilities and products, Prunus mume extinct (PME) was applied to the pilot plant system of dairy industry and yogurt, PME showed thermal and pH stability in the wide spectrum of temperature ($40{\sim}150^{\circ}C$) and pH ($4{\sim}10$) and remarkable antimicrobial activities against dairy spoilage microorganisms. As the result of aseptic treatment of dairy processing facilities with PME microbial colony including coliform bacteria was not detected canpore to those detected in the control. In the level of PME concentration which inhibit the growth of putrefactive microorganisms we could produce yogurt with good scores of sensory evaluation.

• Weed & Turfgrass Science
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• v.5 no.1
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• pp.42-50
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• 2016

Superintendents have been used microbial fertilizers to improve turfgrass growth and quality and to decrease turfgrass diseases in golf course. This study was conducted to investigate the effects of compound fertilizer containing microbe (MF) on the growth and quality of creeping bentgrass with turf color index (TCI), chlorophyll index (ChI), root length, turfgrass density, clipping yield and nutrient content. Treatments were designed as follows; non-fertilizer (NF), compound fertilizer (21-17-17; CF) as control, compound fertilizer (14-6-17) containing microbe. In pot experiment, TCI and ChI of creeping bentgrass in MF plot were similar to those in CF. But clipping dry weight of MF plot increased by 39.1% compared to that of CF plot. At field experiment applied with MF treatment, TCI, ChI, root length, and nutrient content and uptake of creeping bentgrass were similar to those with CF treatment, but turfgrass density with MF higher about 7.9-15.8% than with CF. These results indicated that the application of MF improved growth and quality of creeping bentgrass by enhancing clipping yield and shoot number.

• Journal of Life Science
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• v.33 no.7
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• pp.593-604
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• 2023

The ocean accounts for over 70% of the Earth's surface and is a space of largely unexplored unknowns and opportunities. Korea is a peninsula surrounded by the sea on three sides, emphasizing the importance of marine research. The ocean has an extremely complex environment with immense biological diversity. In terms of microbiology, the marine environment has varying factors like extreme temperature, pressure, solar radiation, salt concentration, and pH, providing ecologically unique habitats. Due to this variety, marine organisms have very different phylogenetic classifications compared with terrestrial organisms. Although various microorganisms inhabit the ocean, studies on the diversity, isolation, and cultivation of marine microorganisms and the secondary metabolites they produce are still insufficient. Research on bioactive substances from marine microorganisms, which were rarely studied until the 1990s, has accelerated in terms of natural products from marine Actinomycetes since the 2000s. Since then, industries for bioplastic and biofuel production, carbon dioxide capture, probiotics, and pharmaceutical discovery and development of antibacterial, anticancer, antioxidant, and anti-inflammatory drugs using bacteria, archaea, and algae have significantly grown. In this review, we introduce current research findings and the latest trends in life science and biotechnology using marine microorganisms. Through this article, we hope to create consumer awareness of the importance of basic and applied research in various natural product-related discovery fields other than conventional pharmaceutical drug discovery. The article aims to suggest pathways that may boost research on the optimization and application of future marine-derived materials.