• 상하수도학회지
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• 제23권6호
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• pp.727-733
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• 2009

This study was performed to investigate the physical characteristics like compressive strength, permeability, porosity and the water quality removal characteristics of permeable concrete pavement filled with microbial-soil sheet to remove SS, organic matter and nutrients in artificial rainfall. As a result, it can show the removal efficiency is SS 90~95%, COD 85~93%, BOD 80~83%, T-N 61~75%, T-P 71~78% on WAPS I(W1) and WAPS II(W2). Therefore, permeable concrete pavement filled with microbial-soil sheet shows higher removal efficiency(SS 10%, organic matter and nutrients 30%) than a conventional porous concrete(W3). By filling microbial-soil sheet to permeable concrete pavement, we confirm that the function and efficiency are improved significantly and that a naturally-friendly facility can be developed and applied to treat non-point sources.

• 한국식품저장유통학회:학술대회논문집
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• 한국식품저장유통학회 2003년도 제23차 추계총회 및 국제학술심포지움
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• pp.188.1-188
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• 2003

To examine the effect of vacuum packaging on the quality of chicken during storage, microbial (total bacterial counts, mold and yeast, E. coli, and Pseudomonas) changes and drip loss were determined. fresh chicken breasts were prepared and packaged using polyethylene film under vacuum and normal atmosphere, respectively. Samples were then stored at 4$^{\circ}C$ for two weeks. At various time intervals during storage, sample was taken homogenized, and diluted with 0.1% sterile peptone water, and followed by microbial counts. Microbial changes of total bacterial counts, mold and yeast, E. coli, and Pseudomonas during storage of chicken were significantly decreased by vacuum packaging. Drip loss was also significantly decreased. These results indicate that vacuum packaging of chicken should be recommended as a suitable storage method in terms of microbial safety as well as quality of chicken.

• Journal of Microbiology and Biotechnology
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• 제34권9호
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• pp.1890-1897
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• 2024

Fermentation has been identified as an effective strategy to alter the chemical makeup of tobacco, thereby enhancing its quality. The deliberate introduction of microorganisms can hasten the fermentation process. In this research, microbial consortia harvested from the tobacco surface were utilized to enhance the tobacco quality. This enhancement also elevated several sensory attributes of HnB cigarettes, such as aroma richness, moisture, strength, and reduced irritation, achieving a sensory quality rating of 84.5. This marks a notable improvement compared to the 82 rating of the original, unfermented cigarettes. Untargeted metabolomics analysis revealed a decrease in total polyphenols and unsaturated fatty acids, while the levels of polyacids, alcohols, ketones, furans, and other compounds increased in the fermented tobacco. Additionally, KEGG pathway enrichment analysis indicated that the enhancement in tobacco quality through microbial consortia fermentation is linked to various biological pathways, with pathways related to fatty acid and amino acid degradation playing pivotal roles. The findings of this study will serve as a reference for the commercial production of HnB cigarettes, and the elucidated mechanism offers a theoretical basis for exploring microbial fermentation as a means to improve tobacco quality.

• Journal of Microbiology and Biotechnology
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• 제20권2호
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• pp.363-369
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• 2010

This study was conducted to investigate the effects of different sanitizers and contact times on storage quality and microbial growth in fresh-cut broccoli. Fresh broccoli samples were cut into small pieces, washed each for 90 s and 180 s in normal tap water (TW), $100\;{\mu}/l$ chlorinated water (CL, pH 7), electrolyzed water (EW, pH 7.2) containing $100\;{\mu}/l$ free chlorine, or $2\;{\mu}/l$ ozonated water ($O_3$). Then, samples were packaged in 30-${\mu}m$ polyethylene bags and stored at $5^{\circ}C$ for 9 days. No significant differences were observed in gas composition and color parameters ($L^*$, $a^*$, $b^*$, and hue angle) among different sanitizers with contact times. No off-odor was detected during the storage. A longer contact time was not effective in reducing microbial population, except with $O_3$ washing. $O_3$ with 90 s was not much effective in reducing microbial population compared with Cl or EW. However, samples washed with $O_3$ for 180 s observed the lowest numbers of total aerobic and coliform plate counts. The result suggested that, a longer contact time of ozone can be used as a potential sanitizer to maintain the microbial quality and safety of fresh-cut broccoli.

• Asian-Australasian Journal of Animal Sciences
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• 제19권2호
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• pp.292-296
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• 2006

Meat marination has been applied to improve product's physical and sensory attributes for years, but usually it is not intended to improve microbial quality of the product. Tumbling, which helps the distribution of marinade solution during processing, should enhance the action of antimicrobial agents. The objective of this study is to evaluate the combined effects of nisin, tumbling and storage time on total microflora and psychrotrophs counts on poultry. A marinade that contained acetic acid (1%) and salt (3%) with pH adjusted to 4 was developed as a standardized marinade. Drumsticks were marinated with various nisin levels (0, 50, or 100 IU/ml) combined with tumbling (0, 10, or 20 min), and then stored at $4^{\circ}C$ for 18 h. The total microflora and psychrotrophs counts of the samples were evaluated after 0, 2, 4, and 7 days of storage. The results indicated that at a given storage time, the samples tumbled for either 10 or 20 min had significantly (p<0.05) lower microbial counts when compared with the samples without the tumbling treatment. The microbial counts of the tumbled samples increased as storage time increased. Microbial counts significantly (p<0.05) decreased when more nisin was increased up to the level of 100 IU/ml. In conclusion, adding of nisin at the level of 50 IU/ml with tumbling for 10 min decreased the total microflora and psychrotrophs counts of the marinated chicken broiler drumsticks.

• 상하수도학회지
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• 제37권6호
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• pp.325-334
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• 2023

Membrane bioreactor (MBR) provides the benefits on high effluent quality and construction cost without the secondary clarification. Despite of these advantages, fouling, which clogs the pore in membrane modules, affects the membrane life span and effluent quality. Studies on the laboratory scale MBR were focused on the control of particulate fouling, organic fouling and inorganic fouling. However, less studies were focused on the control of biofouling and microbial aspect of membrane. In the full scale operation, most MBR produces high effluent quality to meet the national permit of discharge regulation. In this study, the performance and microbial community analysis were investigated in two MBRs. As the results, the performance of organic removal, nitrogen removal, and phosphorus removal was similar both MBRs. Microbial community analysis, however, showed that Azonexus sp. and Propionivibrio sp. contributed to indirect fouling to cause the chemical cleaning in the DX MBR.

• 한국식품저장유통학회지
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• 제14권1호
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• pp.54-60
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• 2007

신선편이 당근채 세척시 오존수 사용에 의한 품질 및 안전성 향상 효과를 구명하기 위해 연구를 수행하였다. 세척 당근을 절단한 뒤 100ppm의 염소수에 1, 2회 세척 및 오존발생장치에서 공급되는 초기 오존수 농도 2ppm에서 1,5, 20분 세척한 뒤 $O_{2}$ 투과율 $29.2pmol{\cdot}s^{-1}{\cdot}m^{-2}{\cdot}Pa^{-1}$ 필름으로 포장하여 $5^{\circ}C$에서 3주간 저장되었다. 당근채의 오존수 세척처리는 저장 중 포장내부의 기체 조성, 당근채의 품질 및 미생물 수에 영향을 미쳤다. 오존수 20분 처리는 당근채 저장 중 $CO_{2}$ 농도가 낮고, 경도가 높았으며, 백화지수(WI), 이취발생 및 미생물 수가 적어 가장 높은 관능점수를 나타내며 저장 3주까지 상품성을 유지하였다. 그러나 염소수 1회 세척은 비록 미생물 수는 오존수 20분 처리와 함께 낮게 나타났으나 품질에 있어서 상대적으로 WI와 이취발생이 높아 오존수 20분 보다 품질변화가 심하였다. 따라서 오존수 20분 처리는 신선편이 당근채의 염소 세척을 대체할 수 있는 방법으로 판단되었다.

• Journal of Microbiology and Biotechnology
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• 제34권3호
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• pp.622-633
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• 2024

For quality standardization, the application of functional lactic acid bacteria (LAB) as starter cultures for food fermentation is a well-known method in the fermented food industry. This study assessed the effect of adding a non-thermally microbial inactivated starter culture to kimchi, a traditional Korean food, in standardizing its quality. In this study, pretreatment based on sterilization processes, namely, slightly acidic electrolyzed water (SAEW) disinfection and ultraviolet C light-emitting diode (UVC-LED) of raw and subsidiary kimchi materials were used to reduce the initial microorganisms in them, thereby increasing the efficiency and value of the kimchi LAB starter during fermentation. Pretreatment sterilization effectively suppressed microorganisms that threatened the sanitary value and quality of kimchi. In addition, pretreatment based on sterilization effectively reduced the number of initial microbial colonies in kimchi, creating an environment in which kimchi LAB starters could settle or dominate, compared to non-sterilized kimchi. These differences in the initial microbial composition following the sterilization process and the addition of kimchi LAB starters led to differences in the metabolites that positively affect the taste and flavor of kimchi. The combined processing technology used in our study, that is, pre-sterilization and LAB addition, may be a powerful approach for kimchi quality standardization.

• Food Science and Biotechnology
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• 제14권6호
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• pp.752-757
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• 2005

Changes in milk quality during storage of extended shelf life milk (ESL milk) and non-ESL milk were evaluated. No significant differences were observed between ESL and typical ultra high temperature-treated (UHT) milk in physicochemical properties including non-casein nitrogen (NCN) content, whey protein nitrogen index (WPNI), and L-ascorbic acid content. Low temperature and long time-treated milk (LTLT milk) had significantly higher NCN content and WPNI than those of UHT milk. In terms of microbial quality, yeast, molds, coliforms, and other bacteria were not detected in ESL milk during entire storage (21 days after expiration date) period at 4 and $25^{\circ}C$, while LTLT milk was more susceptible to microbial infection. Rats fed ESL milk resulted in significantly higher body weight, average daily gain, and feed efficiency than those given UHT milk. These results suggest ESL milk maintains better microbial quality than typical UHT milk, particularly during storage under extended refrigeration and at high temperature.

• Asian-Australasian Journal of Animal Sciences
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• 제33권7호
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• pp.1103-1112
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• 2020

Objective: To measure whether a microbial additive could effectively improve the fermentation quality of delayed-sealing (DS) silage, we studied the effects of inoculants of lactic acid bacteria (LAB) and cellulase enzyme on microbial populations, ensiling characteristics, and spoilage loss of DS silage of Napier grass in Africa. Methods: Quick-sealing (QS) and DS silages were prepared with and without LAB (Lactobacillus plantarum) inoculant, cellulase enzymes, and their combination. The QS material was directly chopped and packed into a bunker silo. The DS material was packed into the silo with a delay of 24 h from harvest. Results: In the QS silage, LAB was dominant in the microbial population and produced large amounts of lactic acid. When the silage was treated with LAB and cellulase, the fermentation quality was improved. In the DS silage, aerobic bacteria and yeasts were the dominant microbes and all the silages were of poor quality. The yeast and mold counts in the DS silage were high, and they increased rapidly during aerobic exposure. As a result, the DS silages spoiled faster than the QS silages upon aerobic exposure. Conclusion: DS results in poor silage fermentation and aerobic deterioration. The microbial additive improved QS silage fermentation but was not effective for DS silage.