• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.9
• /
• pp.384-390
• /
• 2018

Air and soil are being contaminated by the environmental pollution as a result of climate change and urbanization, resulting in water pollution reaching serious levels. In this studies, we investigated the use of antimicrobial copper for the removal of biological pollutants from water system. Specifically, we tested its effects against E. coli, B. subtilis, S. aureus, K. pneumoniae and P. aeruginosa. Made a sphere shape having a diameter of 2cm using a strip-shaped copper wire of 0.5g, 1g and 2g. And then, to confirm the antimicrobial activities, each copper ball was equipped in the broth which inoculated each pathogens. The results showed that bacterial growth of the five test bacteria was inhibited by more than 99% after reaction with a 0.5 g copper ball for at least 20 minutes. Based on the these results, if perform the further experiment such cytotoxicity, it is expected that will be enough to be used as a filter for water quality purification. The developed technique is expected to be widely applied in various industries.

• Korean Journal of Veterinary Research
• /
• v.24 no.2
• /
• pp.149-162
• /
• 1984

The research was conducted(1) to confirm the agent(s) responsible for the antimicrobial activity contained in the fermented tomato juice with L. acidophilus(2) to extract and purify the antimicrobial agent(s)(3) to find the biological, physical and chemical properties of the agent(s). The following results were obtained and summarized as followings; 1. The agent responsible for the inhibitory activity was confirmed by both well assay method using fermented tomato juice with L. acidophilus and turbidimetric technique using the cell-free filtrate or neutralized filtrate of tomato acidohilus culture and found exerted antimicrobial agent other than lactic acid. 2. The procedures of purification : The isolation and purification of antimicrobial agent from the lyophilized acidophilus tomato culture were carried out by (1) methanol extraction (2) acetone extraction, (3) Sephadex G-50 gel filtration (4) paper chromatography and (5) thin layer chromatography. 3. The biological, physical and chemical properties of antimicrobial agent: The biological, physical, chemical properties of the purified antimicrobial agent were: (1) The antimicrobial activity was strong against test organisms; Bacillus subtilis(ATCC 6633), Escheichia coli(ATCC 25922), Staphylococcus aureus(ATCC 167), Pseudomonas fluorescens(KFCC 32394), Proteus vulgaris and Shigella dysenteriae. (2) The pH value of the agent was 2.0 and the inhibitory activity was lost when it was neutralized at 7.0 of pH and the agent was heat stable at $121^{\circ}C$ for 60 minutes. (3) The ultraviolet light absorption spectra of methanol-acetone extract and TLC fraction exhibited a maximum absorption at 260nm and 224nm respectively. (4) The most purified agent from TLC plate increased about 130-fold in activity. (5) The agent isolated from TLC plate was free from $H_2O_2$ or lactic acid. 4. Bioautographic assy: By means of bioautography of the agent on silica gel of TLC plate a strong inhibitory activity against B. subtilis was demonstrated. 5. Mass spectrometry: The agent obtained from TLC plate was analyzed by mass spectrometry which show the parent peak at m/e 264 suggesting the molecular weight of the compound and molecular group such as [$C_2H{^+}_4$], [CO], [CH=NH], [$C_3{H^}4_7$], [$\begin{array}{rcl}O\\{\parallel}\\CH_3-C\\\end{array}$], [$C_6-H{^+}_{11}$], [$C_5H{^+}_{11}$], [$\begin{array}{rcl}O\\{\parallel}\\C_5H_7-C^+\\\end{array}$] were suggested.

• Journal of Food Hygiene and Safety
• /
• v.32 no.4
• /
• pp.306-313
• /
• 2017

This study systemically analyzed the data on the microbial levels in fresh vegetables in Korea to identify the points to control. We scanned the studies published between 2001 and 2015 in peer-reviewed research papers on the microbial levels in fresh vegetables produced in Korea. Plant products were categorized by using the US IFSAC (Interagency Food Safety Analytics Collaboration) category. The most consumed, the non-heat treated, the epidemiological foodborne diseases sources of fresh vegetable in foodservice (KCDC data) were identified by literature review. Articles were screened using National Digital Science Library (NDSL) search engine regarding to microbial hazards in plant products. Based on the total plate count number and coliforms on the 89 data cases from 26 published articles, the total plate count number was high in the order of sprouts, leaf and stem, bulbs and roots, vine-grown, solanaceous, melons, and pome. Escherichia coli was frequently detected in leaf and stem and sprouts products. Focused on the microbial data of leek, lettuce and cabbage, the levels of total plate count, coliforms and Bacillus cereus showed the levels of 4.15~7.69 log CFU/g, 1~6.99 log CFU/g, and 0.51~3.9 log CFU/g, respectively, by 33 published papers. The levels of environmental factors affecting the microbial safety of lettuce and leek before harvest were investigated. Manure, soil, hands, scale, gloves were the major potential microbial contamination points to control. In addition, GAP (good agricultural practice), microbial testing, and improvement of irrigation methods are required to provide the safer fresh produce.

• Applied Chemistry for Engineering
• /
• v.19 no.2
• /
• pp.145-150
• /
• 2008

In this work we have studied the antifouling properties of the hydrophobic sol-gel modified sensing membrane and its optical properties for sensor application. E. coli JM109, B. cereus 318 and P. pastoris X-33 were cultivated in confocal cultivation dishes with glass surface, respectively. The glass surface was coated with the hydrophobic sol-gels prepared by the dimethoxy-dimethyl-silane (DiMe-DMOS) and tetramethyl-orthosilicate (TMOS). After cultivation, microorganisms adhered on the surface coated with sol-gels and glass surface were dyed by gram-staining method and the numbers of microorganisms were analyzed based on the image data of the scanning electronic microscope (SEM). A great number of microorganisms, about $2{\sim}3{\times}10^4/mm^2$, was adhered on the glass surfaces which no hydrophobic sol-gels were coated. But, the antifouling effect of the hydrophobic sol-gels was large, that microorganisms of less than $200{\sim}300/mm^2$ were adhered on the coated glass surface. The performance of the sensing membranes for detection of pH and dissolved oxygen was enhanced by recoating the light insulation layer prepared with the mixture of the hydrophobic sol-gel and graphite particles.

• Korean Journal of Environmental Agriculture
• /
• v.31 no.4
• /
• pp.368-374
• /
• 2012

BACKGROUND: The urgency of feeding the world's growing population while combating soil pollution, salinization and desertification requires suitable biotechnology not only to improve crop productivity but also to improve soil health through interactions of soil nutrient and soil microorganism. Interest in the utilization of microbial fertilizer has increased. A principle of nature farming is to produce abundant and healthy crops without using chemical fertilizer and pesticides, and without interrupting the natural ecosystem. Beneficial microorganisms may provide supplemental nutrients in the soil, promote crop growth, and enhance plant resistance against pathogenic microorganisms. We mixed beneficial microorganisms such as Bacillus sp. Han-5 with anti-fungal activities, Trichoderma harziaum, Trichoderma longibrachiatum with organic material degrading activity, Actinomycetes bovis with antibiotic production and Pseudomonas sp. with nitrogen fixation. This study was carried out to investigate the mixtures on the soil microflora and soil chemical properties and the effect on the growth of lettuce and cucumber under greenhouse conditions. METHODS AND RESULTS: The microbial mixtures were used with each of organic fertilizer, swine manure and organic+swine manure and compared in regard to changes in soil chemical properties, soil microflora properties and crop growth. At 50 days after the treatment of microorganism mixtures, the pH improved from 5.8 to 6.3, and the EC, $NO_3$-Na and K decreased by 52.4%, 60.5% and 29.3%, respectively. The available $P_2O_5$ and $SiO_2$ increased by 25.9% and 21.2%, respectively. Otherwise, the population density of fluorescent Pseudomonas sp. was accelerated and the growth of vegetables increased. Moreover, the population density of E. coli and Fusarium sp., decreased remarkably. The ratio of bacteria to fungi (B/F) and the ratio of Actinomycetes bovis to fungi (A/F) increased 2.3 (from 272.2 to 624.4) and 1.7 times (from 38.3 to 64), respectively. Furthermore, the growth and yield of cucumber and lettuce significantly increased by the treatment of microorganism mixtures. CONCLUSION(S): These results suggest that the treatment of microorganism mixtures improved the chemical properties and the microflora of soil and the crop growth. Therefore, it is concluded that the microorganism mixtures could be good alternative soil amendments to restore soil nutrients and soil microflora.

• Journal of Food Hygiene and Safety
• /
• v.8 no.4
• /
• pp.241-249
• /
• 1993

This study was performed to investigate the remainity of synthetic surfactant (LAS) by HPLC and the microbial contamination on stainless steel dishes. For the maintenance and the improvement of school lunch program's safety, the remainity of synthetic surfactants (LAS) on stainless steel dishes washed with auto dishwasher was investigated by HPLC, and the microbial contamination on same dishes was surveyed. The results were as follows: (1) The remainity of synthetic surfactant (LAS) a) The residue of LAS was very small because of the repeated washing of dishes by strong pressurized water. b) The remainity range of LAS on stainless steel dishes was 2.1~7.2 $\mu\textrm{g}$/dish. The remainity of general surfactants was higher in cold water then warm water. The amount of residual general surfatants was 5.95 $\mu\textrm{g}$/dish in cold water, and 2.95 $\mu\textrm{g}$/dish in warm water. There was no difference of the remainity of special surfactants by water temperature. The amount of residual surfactants was 3.9 $\mu\textrm{g}$/dish. c) There was no difference of residue amount by washing times. (2) The microbial contamination after washing with general surfactants. 1) The mean MPN of E. coli was 203(53~345) on 1 hr, 19(6~28) on 2 hrs, in cold water, and 1100(only 1 dish of 1 school) on 1 hr, 24(6~42) on 2hrs. 2) After washing with general surgactants the mean of contamination by general microbials was 956(25~2300)on 1 hr, 694(45~2500) on 2 hrs. in cold water and 803(5~2300) on 1 hr, 671(5~2500)on 2 hrs. After washing with special surfactants the mean of contamination by general microbials was 788(136~2900) on 1 hr, 1122(15~3000) on 2 hrs, in cold water and 537(5~2000) on 1 hr, 88(15~150) on 2 hrs in warm water. (3) Like the results of this study, the good washing methods of stainless steel dishes for school luch program were as follows. First, for washing stainless steel dishes, the use of special surfactants was recommended at 30~4$0^{\circ}C$ water. Second, at 7$0^{\circ}C$ water, the rinsing of dishes was recommended. Third, the final rinsing at 8$0^{\circ}C$ combined with simple disinfection and dry was recommended.

• KSBB Journal
• /
• v.24 no.3
• /
• pp.273-278
• /
• 2009

The purpose of this work was to investigate the antibacterial activity of Lactobacillus plantarum YK-9 isolated from fermented Kimchi. Morphological and biochemical characteristics of L. plantarum YK-9 were examined. Phylogenetic analysis using 16S rRNA sequencing was performed to identify the strain, and the strain could be assigned to Lactobacillus plantarum, designated as L. plantarum YK-9. The strain was registered in GenBank as [FJ669130]. During the incubation period of L. plantarum YK-9, the changes of bacterial growth and residual organic acids were monitored. HPLC was used to confirm the organic acids produced in the cultures as metabolites. L. plantarum YK-9 produced both lactic acid and acetic acid, which were responsible for the pH decrease during growth. Initial pH 7.0 of the cultures decreased to 3.6 at the incubation after 72 hours, and concentrations of lactic acid and acetic acid increased to approximately 588.7 mM and 255.5 mM, respectively. The antibacterial activities against food-poisoning causing bacteria were examined with 20-fold concentrated culture supernatants from L. plantarum YK-9, and the antibacterial effects were clearly observed against all the bacteria tested in this work.

• Food Science and Preservation
• /
• v.18 no.5
• /
• pp.764-772
• /
• 2011

Hot-water and 70%-ethanol Smilax china leaf extracts were prepared, and their total polyphenol and flavonoid contents, DPPH-radical-scavenging ability, nitrite-scavenging ability, and antimicrobial activity were determined. The total polyphenol contents of the hot-water and ethanol extract were $5.433{\pm}0.171$ and $13.060{\pm}0.110mg/g$, respectively; their flavonoid contents were $1.599{\pm}0.017$ and $3.005{\pm}0.084mg/g$; their DPPH-radical-scavenging abilities, assayed at 1.0 mg/mL, were 33.6 and 92.3%; and their nitrite-scavenging abilities, assayed at 0.1-2.0 mg/mL, were 37.9-61.6 and 38.4-77.8%. The 70%-ethanol extract showed higher antimicrobial activity than the hot-water extract. The antimicrobial activities were high in Bacillus cereus, Vibrio parahaemolyticus, Salmonella typhymurium, and Staphylococcus aureus, in that order. The antimicrobial substances in the two extracts were maintained after heating at $65-125^{\circ}C$ for 30 min.

• Journal of the East Asian Society of Dietary Life
• /
• v.19 no.1
• /
• pp.32-37
• /
• 2009

This study was carried out to gather basic data on the restoration and extent of Don tea (a coin-shaped tea), the traditional tea of Korea. We examined the physicochemical components and anti-microbial activity of Don tea extracts at 0, 5 and 10 months. The Hunter value $L^*$, of Don tea extracts which were matured for 10 months decreased from 7.01 to 4.97 compared to that when the extracts were first manufactured. However, the $b^*$ value increased from 0.09 to 2.67. There were higher contents of inorganic matter in Don tea extracts following manufacture in the order of K (14.12 mg/100 mL), Mg (0.94 mg/100 mL), P (0.88 mg/100 mL), Ca (0.16 mg/100 mL) and Mn (0.16 mg/100 mL). Classified catechins contents were found in the order of C (19.97 mg/100 mL), EGC (9.30 mg/100 mL), ECG (9.02 mg/100 mL), GCG (8.50 mg/100 mL), GC (7.61 mg/100 mL) and CG (5.63 mg/100 mL). The longer the maturation period of the Don tea extracts, the lower the contents of inorganic matter and catechins. However, this did not apply to the total phenol contents, particularly in the phenol contents of Don tea extracts matured for 10 months which increased by 93.82 mg/l00 mL. Don tea extracts which were matured for longer periods showed higher anti-microbial activities against Bacillus subtilis and Streptococcus mutans. However, there were lower activities against Staphylococcus aureus, Escherichia coli and Salmonella enteritidis. Consequently, it was concluded that a shorter maturation period was required for the effective utilization of the inorganic matter, the catechins and the gram-negative bacteria in the Don tea extracts. However, a longer maturation period of 10 months was found to effectively utilize the total phenol compound contents and the gram-positive bacteria.

• Korean Journal of Veterinary Research
• /
• v.39 no.3
• /
• pp.523-530
• /
• 1999

Sal enteritidis thin fimbriae, SEF14, were found to be restricted to the predominantly poultry-associated members of the Salmonella serogroup D1 that are considered as the important pathogens in poultry industry. SefA together with sefB and sefC encode the proteins involved in SEF14 biosynthesis. In order to develop the rapid and specific detection methods for Salmonella serogroup D1, a PCR technique for the amplification of sefA gene was established, and its specificity and sensitivity were investigated with various microorganisms. The bacterial genomic DNA was extracted by colony-picking and rapid boiled-lysate technique. In comparison of Sef I and Sef II primers used in the PCR, Sef I primer for sefA gene of 513bp showed higher specificity than that of Sef II. The established PCR was as sensitive as to detect 1pg of Sal enteritidis DNA. When 73 strains in 28 genera including the reference strains and the field isolates of various Salmonella serotypes, Bacillus subtilis, Bordetella bronchisepdca, E coli, Listeria spp., Micrococcus luteus, Rhodococcus equi, Staphylococcus spp., Streptococcus spp., Vibrio parahemolyticus, Yersinia spp. were studied, the established PCR yielded specifically positive results with only Salmonella serogroup D1. The results suggested that the PCR for sefA gene could be a potential candidate among the specific detection methods for Salmonella serogroup D1.