• Title/Summary/Keyword: microbial indicators

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Storage Stability of Vacuum-packaged Dry-aged Beef during Refrigeration at 4℃

  • Kim, Seonjin;Lee, Hyun Jung;Kim, Minsu;Yoon, Ji Won;Shin, Dong Jin;Jo, Cheorun
    • Food Science of Animal Resources
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    • v.39 no.2
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    • pp.266-275
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    • 2019
  • Although the production of dry-aged beef has been increasing, most purveyors are unaware of the changes in quality that ensue after completion of the aging period and do not adhere to specific guidelines for its packaging and storage. The objective of this study was to investigate the storage stability of vacuum-packaged dry-aged beef based on changes in microbial, physicochemical, and sensory properties during refrigeration at $4^{\circ}C$ for 21 d. The total aerobic bacterial count exceeded 6 Log CFU/g at approximately day 11 and significantly increased after day 14. Freshness indicators such as pH and volatile basic nitrogen content were acceptable until day 14 and 21, respectively. Based on the evaluation of overall sensory acceptability, the dry-aged beef was acceptable until 14 d without any sensory deterioration. Therefore, vacuum-packaged dry-aged beef could be stored for 11 d at $4^{\circ}C$ without any adverse effect on its microbial and sensory quality.

Crop Effects on Soil Microorganism Activity and Community Composition in the Agricultural Environment (농경지에서 재배작물이 토양미생물활성 및 군집구성에 미치는 영향)

  • Bak, Gyeryeong;Lee, Jeong-Tae;Jee, Samnyu
    • Journal of Environmental Science International
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    • v.30 no.5
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    • pp.379-389
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    • 2021
  • Soil microorganism activity in an agricultural field is affected by various factors including climate conditions, soil chemical properties, and crop cultivation. In this study, we elucidate the correlation between microorganism activity and agricultural environment factors using the dehydrogenase activity (DHA) value, which is one of the indicators of soil microbial activity. As a result, the various factors noted above were related to the DHA value. Annual rainfall, soil Mg2+, bacterial and fungal diversities, types of crops, developmental stages, seasons, and cultivation status were highly correlated with the DHA value. Furthermore, next-generation sequencing (NGS) analysis was used to identify that the type of crop affected soil microbial compositions of both bacteria and fungi. Soil used for soybean cultivation showed the highest relative abundance for Verrucomicrobia, Planctomycetes, and Acidobacteria but Actinobacteria and Firmicutes had the lowest relative abundance. In the case of soil used for potato cultivation, Actinobacteria had the highest relative abundance but Proteobacteria had the lowest relative abundance. Armatimonadetes showed the highest relative abundance in soil used for cabbage cultivation. Among the fungal communities, Mortierellomycota had the highest relative abundance for soybean cultivation but the lowest relative abundance for cabbage cultivation; further, Rozellomycota, Chytridiomycota, and Cercozoa had the highest relative abundance for cabbage cultivation. Basidiomycota had the highest relative abundance for potato cultivation but the lowest relative abundance for soybean cultivation.

A Study on Bacterial Contamination of Cooking Environments of Food Service Operations at University (대학 구내식당 식품위생환경의 세균오염도 조사연구)

  • Park, SungJun;Yun, Hyun Sun;Lee, Sujin;Yang, Minji;Kwon, Bomi;Lee, Cheonghoon;Ko, GwangPyo
    • Journal of Environmental Health Sciences
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    • v.40 no.2
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    • pp.88-97
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    • 2014
  • Objectives: The aim of this study was to evaluate the occurrence of microbiological contamination of kitchen utensils and environments of food service operations at university located in Seoul, Korea. Methods: We collected swab samples from the surfaces of knives, chopping boards, floors, and drains, as well as drinking water and airborne bacteria samples from 20 food service operations. Three bacterial indicators and five food poisoning bacteria were measured quantitatively and qualitatively, respectively. We used selective culture media and the PCR assay targeting 16S rRNA gene for the microbiological analysis. Results: We detected bacterial indicators on knives or chopping boards in eight different food service operations and, three food service operations (I, M, and O) showed more than 3 log colony forming units $(CFU)/100cm^2$ on their knives, significantly higher than the others. The levels of bacterial indicators on the floors and drains in the cooking areas were much higher than those on the cooking utensils. S. aureus was detected on 10 floors and 8 drains. Culturable bacteria were identified in 5 drinking water samples, and food service operation B ($431.1CFU/m^3$) and C ($551.2CFU/m^3$) showed more than $400CFU/m^3$ of total airborne bacteria. Conclusions: These results suggest that some of food service operations in this study may require additional investigation to secure the microbial safety of cooking environments. In addition, further actions including hygiene education for employees and proper guidelines to maintain clean cooking environments should be prepared.

Distribution of Microflora and Mesofauna in the Forest Soils of Gwangneung Experimental Forest (광릉시험림 산림토양의 미생물상 및 중형동물상 분포)

  • Eo, Jinu;Park, Byung Bae;Park, Kee-choon;Chun, Jung Wha
    • Journal of Korean Society of Forest Science
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    • v.100 no.4
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    • pp.681-686
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    • 2011
  • The aim of this study was to investigate the distribution of soil biota across forest types and soil depths in Gwangneung Experimental Forest. We selected 5 sites, which are 3 deciduous- and 2 coniferous forests. The abundance of microflora in these areas was analyzed by the phospholipid fatty acid (PLFA) indicators, and the density of mesofauna was measured by the abundance of nematodes and microarthropods. The abundance of soil microflora was higher in the A layer than in the B layer based on the PLFA indicators, but there were no differences between deciduous and coniferous forests. Average density of nematodes was higher in the A horizon than in the B horizon. The density of fungivorous nematodes was higher in the deciduous forests. Mean densities of Collembola and Oribatida were 44% and 42% of microarthropods in soil samples, respectively. The results of microbial PLFA indicators were significantly correlated with the density of their consumers, which reflected that the food web in fungi- and bacteria-based soil developed in this forests. This study suggested that the distribution of soil organisms largely separated by soil depths and was slightly affected by the forest type in the Gwangneung Experimental Forest.

Monitoring of fecal contamination in a partly restored urban stream in Seoul, Korea

  • Seo, Eun-Young;Jung, Dawoon;Yong, Seung-Cheon;Park, Rho Young;Lee, Young-Ok;Ahn, Tae-Seok
    • Environmental Engineering Research
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    • v.21 no.2
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    • pp.211-218
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    • 2016
  • Cheonggye-cheon is a partly restored urban stream located in central Seoul. We monitored fecal contamination using three different fecal indicators, total coliforms (TC), fecal coliforms (FC) and E. coli, to assess differences in each indicator on days of varying weather conditions. Presumptive TC, FC and E. coli colonies were identified by their 16S rRNA sequences. The results showed that enumeration of E. coli provided a better reflection of fecal contamination of the stream than TC and FC. The main sources of contamination were the inflow of fecal-polluted groundwater from the vicinity of a subway line and two inflowing streams. The fecal contamination was worsened on days with heavy rain because untreated sewage from a collecting facility flowed into the stream. Moreover, growth potential of fecal indicator (E. coli) in situ induced by algal exudates was measured. Our results suggest that an appropriate standard based on E. coli rather than TC and FC should be established for improving water quality management strategies of Cheonggye-cheon in the future.

Comparison of α1-Antitrypsin, α1-Acid Glycoprotein, Fibrinogen and NOx as Indicator of Subclinical Mastitis in Riverine Buffalo (Bubalus bubalis)

  • Guha, Anirban;Guha, Ruby;Gera, Sandeep
    • Asian-Australasian Journal of Animal Sciences
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    • v.26 no.6
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    • pp.788-794
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    • 2013
  • Mastitis set apart as clinical and sub clinical is a disease complex of dairy cattle, with sub clinical being the most important economically. Of late, laboratories showed interest in developing biochemical markers to diagnose sub clinical mastitis (SCM) in herds. Many workers reported noteworthy alternation of acute phase proteins (APPs) and nitric oxide, (measured as nitrate+nitrite = NOx) in milk due to intra-mammary inflammation. But, the literature on validation of these parameters as indicators of SCM, particularly in riverine milch buffalo (Bubalus bubalis) milk is inadequate. Hence, the present study focused on comparing several APPs viz. ${\alpha}_1$-anti trypsin, ${\alpha}_1$-acid glycoprotein, fibrinogen and NOx as indicators of SCM in buffalo milk. These components in milk were estimated using standardized analytical protocols. Somatic cell count (SCC) was done microscopically. Microbial culture was done on 5% ovine blood agar. Of the 776 buffaloes (3,096 quarters) sampled, only 347 buffaloes comprising 496 quarters were found positive for SCM i.e. milk culture showed growth in blood agar with $SCC{\geq}2{\times}10^5$ cells/ml of milk. The cultural examination revealed Gram positive bacteria as the most prevalent etiological agent. It was observed that ${\alpha}_1$-anti trypsin and NOx had a highly significant (p<0.01) increase in SCM milk, whereas, the increase of ${\alpha}_1$-acid glycoprotein in infected milk was significant (p<0.05). Fibrinogen was below detection level in both healthy and SCM milk. The percent sensitivity, specificity and accuracy, predictive values and likelihood ratios were calculated taking bacterial culture examination and $SCC{\geq}2{\times}10^5$ cells/ml of milk as the benchmark. Udder profile correlation coefficient was also used. Allowing for statistical and epidemiological analysis, it was concluded that ${\alpha}_1$-anti trypsin indicates SCM irrespective of etiology, whereas ${\alpha}_1$-acid glycoprotein better diagnosed SCM caused by gram positive bacteria. NOx did not prove to be a good indicator of SCM. It is recommended measuring both ${\alpha}_1$-anti trypsin and ${\alpha}_1$-acid glycoprotein in milk to diagnose SCM in buffalo irrespective of etiology.

Changes in Soil Biota Affected by the Application of Organic Materials in Reclaimed Upland and Paddy-converted Soils Cultivated with Korea Ginseng (개간 및 답전윤환 인삼재배지에서 유기물처리에 따른 토양생물상 변화)

  • Eo, Jin-U;Park, Kee-Choon;Yeon, Byung-Ryul
    • Korean Journal of Soil Science and Fertilizer
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    • v.44 no.5
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    • pp.872-877
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    • 2011
  • Cultivation of Korea ginseng in newly reclaimed and paddy-converted fields has been increasing, and evaluation of organic amendment effectiveness is needed in the two soil types. Soil organisms influence organic matter decomposition, and their responses to applications of organic matter were studied. De-oiled cake and compost were applied at $20Mg\;ha^{-1}$ and $40Mg\;ha^{-1}$ in both soil types. Changes in microflora were assessed by analyzing phospholipid fatty acid (PLFA). The abundance of nematodes and microarthropods was measured. Microbial PLFA indicators for microorganisms and microarthropod abundance were greater in reclaimed upland than in paddy-converted soil. There were few differences in the microflora and fauna of reclaimed uplands, regardless of treatment. In paddy-converted soil, the abundance of Oribatida was increased by the application of compost at $20Mg\;ha^{-1}$ and was correlated with PLFA indicators of fungi. The results suggested a minimal influence of organic amendments in reclaimed upland, because the organic matter content and abundance of soil organisms are low in mineral soils. In paddy-converted soil, the effects of organic amendment differ among different soil organisms, and soil properties are important mediators of the effect.

Effect of Immunoglobulin Y on Growth Performance and Blood Immunological Parameters in Holstein Calves (난황항체(IgY) 급여가 Holstein 송아지의 성장능력 및 면역관련 혈액 지표에 미치는 영향)

  • Jung, Hee-Sung;Jung, Keun-Ki;Jang, In-Surk
    • Journal of Animal Science and Technology
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    • v.51 no.4
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    • pp.321-328
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    • 2009
  • A total of fourteen, 1-wk-old male Holstein calves were allotted into two groups consisted of control (CON) and IGY which was orally administrated with immunoglobulin yolk (IgY) for 1wk. Calves in both groups were provided with milk replacer according to feeding program and had ad libitum access to timothy hay for the entire experimental period (7wks). At 0, 7 and 49 day of experiment, blood samples were collected from the jugular vein of calves to investigate blood biochemical profiles and the differential count (%) of white blood cell (WBC). We also monitored growth performance and colony forming unit (CFU) of fecal microbial population in calves. The adminstration of IgY in calves did not affect body weight and weight gain during 49 days feeding trial compared with control group. The CFU of E. coli and Lactobacilli in the feces of calves were not significantly affected by IgY treatment, whereas the score of the calf scours during day 43 to 49 in IgY group showed a significant (P<0.05) solid type. There were no differences in plasma biochemical components including total protein, albumin, immunoglobulin and the other indicators. As for WBC differential count (%), there was no statistical difference in the percentages of neutrophil, lymphocyte, monocyte, eosinophil and basophil at 0, 7 and 49 days after the oral supplementation of IgY. In conclusion, the oral supplementation of IgY as an immunostimulant did not affect growth performance, fecal microbial population, blood biochemical profile and WBC differential count in Holstein calves.

CARIES-RELATED MICROBIOLOGICAL SCREENING IN CHILDREN UNDER THREE YEARS OF AGE (3세이하의 어린이의 치아우식증과 관련된 미생물학적 선별검사)

  • Park, Jae-Hong;Lee, Keung-Ho
    • Journal of the korean academy of Pediatric Dentistry
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    • v.30 no.4
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    • pp.728-737
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    • 2003
  • To evaluate microbial data and salivary measurements from clinically compatible, culture-based screening procedures employed with children younger than 36 months old. Plaque and stimulated saliva specimens were collected from 87 children. The pH of each saliva sample was measured before and after 0.94% lactic acid was added. Specimens were diluted and plated on selective media and non-selective media. Data collected were counts of mutans streptococci (MS) and lactobacilli (LB). In addition, total viable counts (TVC) of specimens, salivary pH and buffering capacity were also assessed. Each variable was compared to caries status of subjects. According to this study, the results were as followed: 1. Highly significant correlation with caries rates were found for counts of MS and LB. 2. The specific counts/ml saliva or plaque above which caries is predicted, or below which caries is not predicted were as follows: 1) Saliva MS; $10^5$ 2) Plaque MS; $2{\times}10^5$ 3) Saliva LB; $10^3$ 4) Plaque LB; $10^3$. 3. Salivary pH and buffering capacity versus caries status were not significant. 4. Microbial screening methods based on mutans streptococci had higher predictive values and odds ratios than methods for lactobacilli. 5. MS counts were clearly the best indicators of caries status in young children. This measurement can easily be obtained in a dental clinical setting both by conventional culture techniques, or commercial kits for MS recovery.

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The Basic Study for the Roof-Harvested Rainwater Quality Characteristics as a Function of Rainfall Duration (강우지속시간에 따른 건물지붕빗물의 성상특성변화에 대한 기초 연구)

  • Kim, Sung-Pyo;Kim, Doo-Cheol;Oh, Jun-Sik;Kim, Lee-Hyung;Min, Kyung-Suk
    • Journal of Wetlands Research
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    • v.14 no.1
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    • pp.11-20
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    • 2012
  • The aim of this study is to accumulate the data about the roof-harvested rainwater quality characteristics for the better rainwater management. According to the results of rainwater quality indicators (pH, COD, TSS, T-N, T-P, $NH_4$-N, $NO_3$-N, enteric bacteria, heterotrophs, Pb, Cd, Cu), the rainwater qualities of the first flush of roof-harvested was the most polluted about 2 or 3 times (more than 100 times in microbial contamination) compared to the qualities of directly collected rainwater. In the first 10 min flush, over the 60% amounts of contaminant were released from the roof during 30 minute rainwater monitoring. Through statistical factor analysis, relatively close items(variables) can be categorized. It is expected that the continuous monitoring of the roof-harvested rainwater will help to design the safe and economical rainwater storage system in Korea.