• The Korean Journal of Community Living Science
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• v.18 no.2
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• pp.241-246
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• 2007

This study was conducted to select and screen for an antifungal bacterial strain showing pathogen inhibitory activity against Diaporthe actinidiae, which causes stem-end rot in kiwi fruit. Four bacterial strains were isolated which strongly inhibit Diaporthe actinidiae from among two hundred and fifty bacterial strains screened from the soil where kiwi fruit were grown. By co-culturing bacterial strain #72 and the pathogen causing the stem-end rot of kiwi fruit, bacterial strain #72 showed 81.0% antifungal activity against Diaporthe actinidiae. Bacterial strain #72 was identified to be from the genus Bacillus sp. based on morphological and biochemical characterization. The bacterialization of culture broth for Bacillus sp. #72 which was sterilized at $121^{\circ}C$ for 15 minutes and than purified by $0.45{\mu}m$ membrane filter showed almost all of the antagonistic activity against Diaporthe actinidiae. We have also confirmed that in vitro treatment of Bacillus sp. #72 cultured in SD+B+P(sugar 5%, soy sauce 3%, beef extract 0.2%, peptone 0.2%) medium efficiently inhibited the growth of Diaporthe actinidiae responsible for stem-end rot in kiwi fruit.

• Journal of Species Research
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• v.4 no.2
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• pp.127-136
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• 2015

As an outcome of the study on the bacterial species diversity in Korea, we report 24 unrecorded bacterial species of Korea belonging to the phylum Firmicutes. The unrecorded species excavated through this study were assigned to 12 different genera of 7 families, namely Bacillus, Halobacillus, Lysinibacillus and Thalassobacillus of Bacillaceae, Brevibacillus and Paenibacillus of Paenibacillaceae, Viridibacillus of Planococcaceae, Salinicoccus and Staphylococcus of Staphylococcaceae, Enterococcus of Enterococcaceae, Lactobacillus of Lactobacillaceae, and Lactococcus of Streptococcaceae, respectively. The bacterial isolates were obtained from various ecosystems in Korea. The isolates were identified based on 16S rRNA gene sequences, and those exhibiting at least 99% sequence similarity with known bacterial species but never reported in Korea were selected as unrecorded species. The selected isolates were subjected to further taxonomic characterization including the analysis of cell shape and fine structure using electron microscope, colony color and shapes, enzyme activities and carbon source utilization. The descriptive information on the 24 unrecorded species are provided.

• Journal of Species Research
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• v.11 no.3
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• pp.133-142
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• 2022

In 2020, 24 bacterial strains were isolated from algae, kudzu leaf, mud, pine cone, seashore sand, sea water, soil, tidal flat, and wetland from the Republic of Korea. Isolated bacterial strains were identified based on 16S rRNA gene sequences, and those exhibiting at least 98.7% sequence similarity with known bacterial species, but not reported in Korea, were highlighted as unrecorded species. These isolates were allocated to the phyla Bacteroidetes and Proteobacteria as unrecorded species in Korea. The four Bacteroidetes strains were classified into the families Chitinophagaceae, Flavobacteriaceae, and Sphingobacteriaceae (of the orders Chitinophagales, Flavobacteriales, and Sphingobacteriales, respectively). The 20 Proteobacteria strains belonged to the Aeromonadaceae, Marinobacter, Microbulbiferaceae, Enterobacteriaceae, Erwiniaceae, Morganellaceae, Yersiniaceae, Lysobacteraceae, Halomonadaceae, Moraxellaceae, Pseudomonadaceae, Steroidobacteraceae, Xanthomonadaceae, and Myxococcaceae (of the orders Aeromonadales, Alteromonadales, Cellvibrionales, Enterobacterales, Lysobacterales, Oceanospirillales, Pseudomonadales, Steroidobacter, Xanthomonadales, and Myxococcales). This study focused on the description of 24 unreported bacterial species in Korea in the phyla Bacteroidetes and Proteobacteria belonging to six classes.

• Food Science and Biotechnology
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• v.16 no.5
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• pp.675-690
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• 2007

Bacteriocins in Gram-positive bacteria have attracted much attention because many have a strong antimicrobial activity also against bacteria outside the genera of the producers. Lantibiotics and the pediocin-like bactericins have attracted most attention since they kill a broad spectrum of Gram-positive bacteria including important pathogens. But many other promising Gram-positive bacteriocins have been thoroughly characterized. Recent studies have shown that bacteriocins may playa role in the intestinal flora to protect us against the food-borne pathogens. Bacterial genome sequencing has demonstrated that there may be an arsenal of such compounds and we are only seeing the top of the iceberg. The present review gives a short outlook of the field of bacteriocins with focus on lactic acid bacteria and includes recent findings.

• Korean Journal of Food Science and Technology
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• v.22 no.1
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• pp.26-32
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• 1990

Attempts were made to define the characteristics of microbial community as an indicator of Kimchi fermentation. Determination of communities was carried out by simple Gram-stain, followed by direct microcopic counts. In room-temperature $(15^{\circ}C)$ fermentation, microbial succession was occurred in the order of communities of Gram-positive bacteria, yeasts and Gram-negative bacteria. It was characteristic that Gram-positive bacterial community was developed during the production of lactic acid, yeasts community was developed to cause rancidity, and Gram-negative bacterial community was relevant to maceration (or softening) as well as rancidity. The fluctuation of apparent Gram-negative reaction group might be used as a criterion of death or aging of Gram-positive bacterial populations. In low-temperature fermentation $(5^{\circ}C)$, however, it was found that yeasts and Gram-negative bacterial communities did not developed but only Gram-positive bacterial community did. It follows from these results mentioned above that maturity of Kimchi depends on the development of Cram-positive bacterial community. Thus, the size and occurrence of microbial community are avaiable for an indicator of Kimchi fermentation, and also determination of community could be a useful method to predict the maturity.

• Journal of Food Hygiene and Safety
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• v.26 no.3
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• pp.242-247
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• 2011

A greening phenomenon has been observed in some plant foods such as chestnut, sweet potato, burdock, and others during processing. The formation of the pigments was postulated as reactions of primary amino compounds with chi orogenic acid or caffeic acid ester, yielding acridine derivatives. Acridine derivatives have been regarded as mutagenetic agents. For the reason, the bacterial reverse mutation test was carried out to evaluate the genotoxicity of green pigment using Salmonella typhimurium TA98 and TA100. Alanine, arginine, aspartic acid, glycine, lysine, and phenylalanine were reacted repectively with chlorogenic acid to synthesize model compound. Green pigment was extracted from sweet potato. Maximum concentration of 2 and 50 mg/plate was tested for the synthetic green pigments and extracted green pigment respectively, taking bacterial survival, solubility, and color intensity into consideration. There was no signigicant increase in the reverse mutation either with or without S9 activation system by any test material. Though further studies with other genotoxicity test system are necessary, both synthetic and sweet potato green pigments seemed not to cause mutation despite the acridine moiety in their structures.

• Korean Journal of Food Science and Technology
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• v.33 no.4
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• pp.461-468
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• 2001

The effectiveness and safety of Enzyme Food, a group of dietary supplements designated by Korean Food Law, were evaluated and the possibility of HACCP (Hazard Analysis Critical Control Point) application was investigated. Chemical composition, enzyme activities and the degree of bacterial contamination in 12 samples of different brands sold in Korean market were measured. The chemical composition of the selected products varied and inconsistent to those claimed in the label description. It is known that effectiveness of Enzyme Food depends on enzyme activity, but enzyme activities of ${\alpha}-amylase$ varied from $1,793\;{\mu}g/min$ g to $159\;{\mu}g/min$ g and those of ${\beta}-amylase$ ranged from $171\;{\mu}g/min$ g to $11\;{\mu}g/min$ g. The protease activities varied from $27.57\;{\mu}g/min$ g to $0.18\;{\mu}g/min$ g. In coli-form bacterial test, positive reactions were appeared in the 50 % of the samples. Numbers of bacteria ranged from $1.3\;{\times}\;10^5\;to\;1.2\;{\times}\;10^9$. Five CCPs were identified; heating, inoculation, cultivation, drying and granulation. Consideration of HACCP system indicated that the pretreatment of raw material, checking of bacterial contamination and stability of enzyme activity during fermentation process were important factors for the quality of Enzyme Foods.

• Korean Journal of Food Science and Technology
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• v.28 no.2
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• pp.260-266
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• 1996

This study was carried out to investigate the bacterial microflora of commercial and traditional Kochujang. Computer aided idetification systems were used to identify the bacteria in Kochujang. Seven genera such as Bacillus, Corynebacterium, Enterococcus, pasteurella, Pseudomonas, Staphylococcus and Streptococcus in commercial process and 10 genera such as Bacillus, Corynebacterium, Enterococcus, Flavimonas, Flavobacterium, Gemella, Pasteurella, Pseudomonas, Staphylococcus and Streptococcus in traditional process were identified. Distribution of genus Bacillus was $56{\sim}70%$ during fermentation in the commercial process and $38{\sim}50%$ in the traditional process. B. lichenoformis strains identified in this study were classified into three types by their physiological characteristics.

• Food Science of Animal Resources
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• v.35 no.2
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• pp.211-215
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• 2015

From the previous study, Enterococcus faecium SH01 was isolated from mukeunji, an over-ripened kimchi, and it produced bacteriocin SH01. Bacteriocin SH01 showed an inhibitory effect against Listeria monocytogenes ATCC 19111, a bacterial strain causing human listeriosis. Crude bacteriocin SH01 was purified by ammonium sulfate precipitation and its inhibitory activity at two concentrations (500 and 1,000 AU/g) against Listeria monocytogenes ATCC 19111 was investigated in ground beef at increasing temperatures (5, 10, 15, and 20℃) for 8 d. The number of Listeria monocytogenes ATCC 19111 significantly decreased (p<0.05) as the concentration of bacteriocin increased from 500 to 1,000 AU/g. Intrinsic crude protease activities in ground beef were examined and increased as the temperature increased. Experiments varying both the concentrations of added bacteriocin SH01 and temperature demonstrated a maximum inhibition (2.33 log reduction of bacteria) in samples containing 1,000 AU/g of bacteriocin SH01 incubated at 20℃. When the crude bacteriocin SH01 solution (1,280 AU/mL) was incubated with crude protease solutions at different temperatures, its activity decreased by only half (640 AU/mL), as assessed in an agar well diffusion assay. The finding that the antilisterial activity of bacteriocin SH01 increased with temperature can be explained by the fact that higher temperatures increase bacterial membrane fluidity, thereby promoting the cellular penetration of bacteriocin SH01 into L. monocytogenes. Bacteriocin SH01 may be an excellent candidate as a biopreservative for controlling L. monocytogenes growth in ground beef.

• Journal of Nutrition and Health
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• v.11 no.1
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• pp.39-43
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• 1978

These experiments were made to investigate the characteristics of cocoon pupas. The proximate composition and fatty acids were analyzed. In order to eliminate the unfavorable odor of cocoon pupas, alkaline treatment and extraction of fat were conducted. The results were as follows. 1) The unfavorable odor can be eliminated through the extraction of fat. Boiling with n-hexane for 1 hour was the best. 2) The cocoon pupas were contaminated with $10^8$ bacterial counts/g at the first eating state. When they were stored at room temperature for 6 days, bacterial counts did not increase inure than $10^8$, but they were putrefacted with bad odor. 3) The powder of defatted cocoon pupas prepared for food material contained around 1.3% moisture, 76.0% protein, 0.8% crude fat, and 4.8% ash. 4) It was not efficient to eliminate unfavorable odor by alkaline treatment. 5) The fatty acids of cocoon pupas are composed of 0.35% myristic acid, 20.90% palmitic acid, 0.5% palmitoleic acid, 7.11% stearic acid, 32.20% oleic acid, 5.48% linoleic acid and 30.31% linolenic acid.