• Journal of Applied Biological Chemistry
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• v.57 no.1
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• pp.83-87
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• 2014

The effects of combined treatment of aqueous chlorine dioxide ($ClO_2$) and fumaric acid on the microbial growth in fresh-cut paprika were investigated. After the combined treatment, the populations of total aerobic bacteria and inoculated Listeria monocytogenes in the paprika sample were reduced by 0.82 and 1.21 log CFU/g, respectively, compared to those of the control. In addition, after 10 d of storage at $10^{\circ}C$, the populations were decreased by 1.21 and 2.10 log CFU/g, respectively. The predictive model for the populations of total aerobic bacteria and L. monocytogenes in the paprika was applied during storage. The prediction equation using Gompertz model was appropriate, based on the statistical analysis such as accuracy factor and bias factor. These results suggest that the combined treatment of aqueous $ClO_2$ and fumaric acid can be an effective technology for microbial decontamination and it can improve microbial safety by decreasing maximum growth rate and increasing lag time of bacteria in the fresh-cut paprika.

• KSBB Journal
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• v.25 no.6
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• pp.520-526
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• 2010

In this work we have investigated the production of catalase from Bacillus sp. strains, which were screened and identified from soil. These strains were cultivated in shaking flasks with tryptic soy broth (TSB) at $30^{\circ}C$ and 200 rpm. Effects of the temperature and pH on the stability of the native catalase and whole cell viability were studied in the temperature range of $25-60^{\circ}C$ and the pH range of 7-13. Korean natural zeolite was added to culture medium and mixed with microorganisms for 24 hours. The native catalase maintained its activity over $50^{\circ}C$. The enzyme acitiviy of the catalase from Bacillus flexus BKBChE-3 was highest among the Bacillus sp. strains studied. Bacillus flexus BKBChE-3 and immobilized Bacillus cells have survived under extreme conditions of over $50^{\circ}C$ and pH 12. 60 mL of 10.5 mM $H_2O_2$ solution were entirely removed within 1 hour with catalase produced from Bacillus sp. on the flask. When Bacillus cells were immobilized on Korean natural zeolite, colony forming unit of Bacillus flexus BKBChE-3 was increased and high efficiency of hydrogen peroxide removal was observed.

• Journal of The Korean Society of Grassland and Forage Science
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• v.42 no.4
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• pp.264-269
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• 2022

The present study investigated effects of microbial additives on the floor of Hanwoo steer manure in barn. The treatment following: without additives (CON); additives (AMA). Each treatment used 3 barns as replication and each barn contained 5 Hanwoos. The Hanwoo steer manure in barns was sub-sampled from 5 sides of pen at 0, 4 and 12 weeks. The sub-samples were used for analyses of chemical compositions, microbial counts, gas emissions and compost maturity. The concentrations of moisture, organic matter, total nitrogen and carbon-to-nitrogen (C/N ratio) of Hanwoo steer manure before the microbial additives were each 59.1%, 83.2%, 1.78% and 50.0%, respectively. The counts of lactic acid bacteria, Yeast, Bacillus subtilis, and Escherichia coli (E. coli) were each 5.94, 6.83, 7,28 and 5.52 cfu/g, but Salmonella was not detected. The ammonia-N gas was 4.67 ppm, but hydrogen sulfide gas was not detected. After 4 weeks, moisture, organic matter, total nitrogen, pH and yeast count were lowest (p<0.05). The lactic acid bacteria, yeast, Escherichia coli (E. coli) and ammonia-N gas were not effects of microbial additives. All treatments was not detected at Salmonella count and hydrogen sulfide emission, and compost maturity was completed. After 12 weeks, the lactic acid bacteria and Bacillus subtilis were highest in AMA, while moisture, yeast and E. coli were lowest (p<0.05). The ammonia-N gas was not effect by microbial additive. Salmonella and hydrogen sulfide emission were not detected in all treatments, and compost maturity was completed. Therefore, in present study, the microbial additive did not affect of gas and compost maturity, but the pathogenic microorganism such as E. coli, were inhibited by microbial additives.

• Microbiology and Biotechnology Letters
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• v.43 no.1
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• pp.38-44
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• 2015

This study was conducted to investigate the effects of electrolyzed water (EW) and hot-air-drying with ultraviolet light (UV) to reduce coliform bacteria of Undaria pinnatifida (UP). The UP was washed in the order of 15% EW, tap water (TW), and distilled water (DW) under following conditions: 15% EW for 10 min (washing: 1 time), TW for 1 min, and DW for 10 min (washing: 5 times). Viable cells, coliform, and mold counts were at 10²-10³ CFU/g in untreated samples. After EW treatment, viable cells, coliform, and molds were not detected in whole samples or on the surface of UP. But, after hot-air-drying at 48°C for 48 h, the number of viable cells, coliform, and molds were 10¹-10⁵ CFU/g. After hot-air-drying at 48°C for 48 h with UV (12-48 h), viable cells, coliform, and molds were not detected in whole samples or on the surface of UP. In respect of color value, there were no significant changes. In sensory evaluation, the UP with hot-air-drying with UV (12 h) had the highest score in overall preference among UV treatment groups. These results suggest that the treatments at 15% EW for 10 min and hot-air-drying at 48°C for 48 h with UV (12 h) were effective to reduce coliform bacteria of the dried Undaria pinnatifida.

• Korean Journal of Environmental Agriculture
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• v.8 no.1
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• pp.55-59
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• 1989

To determine the accurate C/N ratio of compost, biodegradable carbon and nitrogen in compost must be analyzed. In biodegradable nitrogen analyzed by Kjeldahl Method, nitrate and nitrite which are available for microbes can not be detected at all. By means of $F{\"{o}}rster$ Method, nitrate and nitrite can be detected. Therefore, various nitrogens in compost were analyzed by Kjeldahl and $F{\"{o}}rster$ Method to investigate the seasonal changes of various C/N ratios of compost. C/N ratios in compost analyzed by Kjeldahl and $F{\"{o}}rster$ Method were decreased rapidly within 2 weeks after composting, then were not changed to 6 weeks, and thereafter were decreased slowly with the lapse of composting time. C/N ratios analyzed by Kjeldahl Method were higher than those analyzed by $F{\"{o}}rster$ Method. C/N ratios of total carbon/total nitrogen analyzed by Kjeldahl Method were higher(5 as C/N ratio or 36%) than those of biodegradable carbon/biodegradable nitrogen analyzed by $F{\"{o}}rster$ Method. Highly positive correlations were observed among C/N ratios of total carbon/total nitrogen analyzed by Kjeldahl Method total carbon/total nitrogen analyzed by $F{\"{o}}rster$ Method and biodegradable carbon/biodegradable nitrogen analyzed by $F{\"{o}}rster$ Method one another.

• Journal of Life Science
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• v.19 no.6
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• pp.751-755
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• 2009

This study was attempted to provide basic data for effective sanitization of sprouts. Sanitization treatments were performed by dipping four sprouts (alfalfa, broccoli, clover and red radish) into chlorine water. Microbial analyses were composed of the total plate count (TPC), coliform count, and E. coli count. All examined sprouts exhibited high levels of TPC ($10^{7}$ CFU/g) and coliform ($10^{6}$ CFU/g). E. coli was detected in broccoli and red radish sprouts in the range of $10^3{\sim}10^4$ CFU/g. Among chlorine water sanitization, the microbial reduction was largest in 100 ppm chlorine water, and its TPC and coliform counts decreased to $8.0{\times}10^5{\sim}2.7{\times}10^6$ CFU/g and $4.3{\times}10^5{\sim}4.6{\times}10^5$ CFU/g, respectively. E. coli was not detected in all sprouts that were given 100 ppm chlorine water treatment. The effective dipping time in 100 ppm chlorine water treatment was 30 min and 60 min, in which TPC were below the microbiological safety limits of ${\times}10^{6}$ CFU/g. Coliform counts were decreased to $9.1{\times}10^4{\sim}2.4{\times}10^5$ CFU/g when the sprouts were dipped for 30min, and kept the similar level after that time. These levels exceeded the microbiological safety limits of $10^{3}$ CFU/g. E. coli was not detected in samples by 100 ppm chlorine water treatment.

• Food Science and Preservation
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• v.12 no.1
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• pp.8-16
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• 2005

To develop natural antimicrobial agents for extending the self-life of Kimchi, the effect of botanical antimicrobial agent-citrus products(BAAC) on microorganisms related to Kimchi spoilage was investigated. The inhibitory effect of BAAC on microorganisms related to Kimchi spoilage was increased according to the concentration of BAAC. Antimicrobial activities of BAAC against microoiganisms related to Kimchi spoilage were remarkably high. The effect of BAAC on the cellular membrane function of microorganisms showed the perturbation of cells in the presence of BAAC. Direct isualization of microbial cells by using both transmission md scanning electron microscope showed microbial cell membrane was destroyed by treating with BAAC. It could be confirmed that BAAC completely inhibit the growth of the test strains. The pH of BAAC-added Kimchi was a little higher than that of the control through the fermentation period. Titratable acidify, vitamin C and viable cells in BAAC-added Kimchi were changed more slowly than those in the control. Sensory evaluation did not show any significant difference between $0.01\%$ BAAC-added Kimchi and the control that showed the best palatabilities during fermentation.

• Applied Biological Chemistry
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• v.49 no.3
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• pp.170-174
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• 2006

For the purpose of developing a high quality agricultural microbial inoculant, methods and materials for improving encapsulation were investigated. Preparation of capsule was conducted by improving extrusion system with micro-nozzle and peristaltic pump. The sodium alginate was selected because of its cheapness, stability of cells, and gel formation ability. The yields, physical properties and gel formation abilities of extractable alginate from sea tangle were investigated by hot water extractable and alkali soluble methods. The extraction yields of hot water extractable alginate (HWEA) and alkali soluble alginate (ASA) from sea tangle were 8 and 20%, respectively. The HWEA was almost not viscous even in 1.5% of the sample solution, whereas the ASA was very highly viscous in above 3% sample solution. The gel formation ability of each samples varied from 1.5% to 5% and the ASA showed a good gel formation ability at 3% solution as commercial alginate (CA). The soil microbial inoculant, Bacillus thuringiensis, Bacillus subtilis, Lactobacillus plantarum and Geotrichum candidum encapsulated sodium alginate with starch and zeolite for stabilizer. The survivability of encapsulated soil microbial inoculant using alginate without stabilizer appeared to be 66, 52, 70 and 50%, respectively. Inclusion of starch and zeolite with alginate bead increased viabilities in Bacillus sp. and Geotrichum candidum by 81-83% and 89%, respectively.

• 한국문화재보존과학회:학술대회논문집
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• 2005.11a
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• pp.252-254
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• 2005

박물관 수장고와 전시실 내의 유기물 문화재는 실내공기에 부유하고 있는 먼지와 곰팡이로 인해 생물적 피해를 받는다. 미생물로 인한 피해를 줄이기 위하여 박물관에서는 환경 조절법을 시행하거나 수장고와 전시실 내에 보존약제를 놓거나 또는 훈증 처리를 통한 방균 방제처리를 시행하고 있다. 미생물의 발생은 문화재 표면의 착색, 재질 분해, 변질 등을 야기한다. 본 연구는 위에 제시된 방법 외에 공기청정기를 이용하여 실내 부유 미생물 수를 줄여 유기물 문화재의 피해를 줄일 수 있는지를 알아보았다. 국립문화재연구소 내 생물과학실의 실험실 한 곳을 임의로 지정하여 공기청정기를 설치하기 전 곰팡이의 수를 측정하고, 공기청정기를 설치한 후의 곰팡이 변화를 4일 간격으로 측정하였다. 또한, 공기 중의 ???r성분 분석을 위하여 가스크로마토그래피(Gas Chromatography)를 이용하였다. 측정결과 곰팡이의 수는 대체적으로 감소하였으며, 채취한 곰팡이를 배양하여 동정을 실시하였다. 곰팡이 동정은 현미경을 통한 형태학적 분류와 ITS(Internal Transcribed Sequence)를 이용한 rDNA(Ribosomal DNA) PCR(Polymerase Chain Reaction)분석 두 가지 방법을 이용하여 동정하였다.

• Food Science and Preservation
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• v.8 no.4
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• pp.374-378
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• 2001

We investigated the change of microfloral states during drying processing and storage of dried persimmon. Initial stave of drying, a total bacteria counts of dried persimmon which was made the rural region of Sangju province were higher than that of downtown but after 7 weeks, there was no differents. A total cell count of bacteria decreased during drying processing but mold and yeast increased. In a storage test of dried persimmon at a different temprature, 3$0^{\circ}C$, room temp. 4$^{\circ}C$, respectively, low temprature storage was effectvie not only to retard the growth of microorganism but also maintain the suitable appearence.