• 제목/요약/키워드: initial pH control

검색결과 461건 처리시간 0.03초

쑥 추출액을 이용한 Microcystis aeruginosa 제거 및 성장억제 연구 (Removal and Regrowth Inhibition of Microcystis aeruginosa using Artemisia asiatica Extracts)

  • 최희정
    • 한국물환경학회지
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    • 제33권4호
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    • pp.441-448
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    • 2017
  • Microcystis aeruginosa (M. aeruginosa) is a cyanobacterium species that can form harmful algal blooms in freshwater bodies worldwide. The use of Artemisia asiatica extracts to control M. aeruginosa inhibition will be environmentally friendly and promising. Artemisia asiatica extracts removed successfully upto 88% of M. aeruginosa pH 8 at $25^{\circ}C$ of temperature. These results was indicated that the amount of 2.24 g/L Artemisia asiatica extracts was removed 1g dryweight/L of M. aeruginosa. The kinetic data showed substrate inhibition kinetics and maximum growth rate was obtained when the M. aeruginosa was grown in medium containing 2.5 g/L of initial concentration of Artemisia asiatica extracts. In the various growth control models, Luong model showed the highest correlation coefficient of 0.9916. Therefore, the Luong model was the most suitable control model for the growth control of M. aruginosa using Artemisia asiatica extracts. In conclusion, the growth control of M. aruginosa using Artemisia asiatica extracts can be applied in the field without controlling the temperature and pH of rivers and streams, and it is possible to control the growth of M. aruginosa efficiently in a short time. The natural extract, Artemisia asiatica extracts, can be a promising inhibition due to its high efficiency and low dose requirements.

염 내성 변이균주 Candida magnoliae M26에 의한 에리스리톨 발효특성 (Fermentation Characteristics of Salt-Tolerant Mutant, Candida magnoliae M26, for the Production of Erythritol)

  • 이강희;서진호;유연우
    • KSBB Journal
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    • 제17권6호
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    • pp.509-514
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    • 2002
  • 발효조건의 최적화에 대한 연구결과 온도는 28$^{\circ}C$, 배지의 초기 pH는 7.0, 통기와 교반 조건은 1.0 vvm과 500 rpm에서 erythritol의 생산이 가장 우수하였다. 이러한 최적의 발효조건에서 250 g/L의 glucose와 5 g/L의 yeast extract가 포함된 발효배지에서 최대 erythritol 농도는 143.3 g/L이었으며, 이때의 수율은 57%이고 생산성은 0.70 g/L-h이었다. 발효 중에 pH를 일정하게 조절하는 경우에 erythritol의 수율 및 생산성은 향상되지 못하였다. 발효배지에 0.5 M의 NaCl 또는 KCl의 첨가에 의해서 염이 첨가되지 않은 배지에 비해 erythritol의 생산이 약간 증가를 하였다. 그러나 NaCl 또는 KCl의 첨가농도가 증가할 수록 erythritol의 생성은 감소하고, 반면에 glycerol의 생성이 증가하였다.

오프셋인쇄 축임물의 전도도가 인쇄적성에 미치는 영향에 관한 연구 (A Study on The Effect of Dampening Conductivity in the Offset Printing Printability)

  • 박찬우;이재수
    • 한국인쇄학회지
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    • 제25권1호
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    • pp.43-52
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    • 2007
  • Offset printing is one of the well known printing technique of lithographic process and consists of image area and 'non-image area on a flat image carrier. The surface tension of dampening water can be controlled by adding IPA after mixing of raw water and etching solution. The etching solution contains a surfactant for reducing surface energy, a clean agent for non-imaging area, wetting agent for protecting non-imaging area from oil components like ink and also an emulsifying agent for controlling emulsification. In this study, the present situation of dampening water maintenance has examined by collecting dampening water using at domestic companies. The pH related to dampening water, conductivity, contact angle, emulsification curve are measured to define the current situation of dampening water control of each companies and to analyze the relationship among measured properties. In the study most of companies among 16 printing companies tested controlling dampening water through pH value. However, the quality of printing has varied depending upon conductivity, contact angle, IPA content, and emulsification value. The control of dampening water should be carry at the state of the standard when adding proper ratio of etching solution. It would be more effective when pH or conductivity control carries out in parallel with controlling dampening water. Therefore the concept that pH5.5 is correct is based concept. Based on these initial tests it is defined that the standardization of dampening water control is required.

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병 포장 갓김치의 항암성에 대한 연구 (Anticancer Effect of Bottled Mustard Leaf Kimchi during Fermentation)

  • 김복남
    • 동아시아식생활학회지
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    • 제18권6호
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    • pp.1063-1071
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    • 2008
  • Mustard Leaf Kimchi (MLK) is a traditional fermented Korean vegetable food. This study investigated the anticancer effect of partial vacuum treatment of MLK packed in glass bottles during fermentation. Prepared vacuum treated mustard leaf Kimchi (VM) and non-vacuum treated mustard leaf Kimchi (CM) were fermented at $5^{\circ}C$ for 8 weeks. The initial pH and total acidity were approximately 5.7 and, 0.36%, respectively. During fermentation, pH decreased and total acidity increased. Initial contents of reducing sugar and salt were 2.1% and were 2.7 mg/g, respectively. Reducing sugar gradually decreased during fermentation. Growth of cells from mouse cancer cell lines (L12l0 and P338D1) and human cancer cell lines (HepG2 and WiDr) were all decreased by MLK. VM and CM did not affect growth. More potent growth inhibition effects were exhibited by water versus hexane extracts of MLK, and by MLK fermented for 3 weeks versus 6 weeks. However, when applied to control NIH/3T3 cells at the same concentrations, MLK exhibited no cytotoxicity, and cell growth was unimpeded.

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칼슘급원 및 보존료 첨가가 김치 발효중 비타민 함량변화에 미치는 영향 (Effect of Calcium-Sources and Preservatives on the Changes of Vitamins during Kimchi Fermentation)

  • 이혜준
    • 대한가정학회지
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    • 제26권1호
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    • pp.51-59
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    • 1988
  • In the present study, an attempt was made to observe the effect of calcium-sources and preservatives on Kimchi fermentation. After pre-fermentation at room temperature for 16 hours, each Kimchi was stored at 4$^{\circ}C$. Changes of vitamin contents(vitamin C, thiamin, riboflavin and $\beta$-carotene) during the fermentation of Kimchi were determined. It was also attempt to relate the fermentation of Kimchi with the changes in chemical and organoleptic characteristics, such as pH, total acidity and reducing sugar. The findings were summarized as follows; 1. During Kimchi fermentation, the pH decreased steady and total acidity increased slowly in the follow order: K-Sorbate+acetic acid, k-Sorbate, Ca-Lactate and Control. the lower of pH and the higher of total acidity, the less of reducing sugar was remained. 2. changes of total vitamin C and reduced ascorbic acid contents during the Kimchi fermentation did not differ significantly from each other. At the begining of fermentation, Kimchi samples contained 20~25mg/100g of total vitamin C and 5~14 mg/100g of reduced ascorbic acid. In the final stage, however, 15~19 mg/100g of total vitamin C and 1~3 mg/100g of reduced ascorbic acid were remained. 3. The contents of thiam in and riboflavin were 30 to 42 meg/100g and 50 to 67 meg/100g at the initial stage, respectively. They increased with the degree of maturity (approximately 2 times of the content of the initial stage) and then gradually decreased. The content of $\beta$-carotene was found to be decreased with the degree of maturity. 4. The results of sensory evaluation indicated that Kimchi added with Ca-Carbonate, Ca-Carbonate+acetic acid and Ca-lactate were better than Control.

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장어 고음의 콩 첨가에 따른 저장중의 이화학적 변화 (The Effect of Soybeans on Storage Characteristics of Eel(Anguilla japonica) Gouem(Thick Broth))

  • 조은자;박나영;임지숙
    • 동아시아식생활학회지
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    • 제15권4호
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    • pp.419-430
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    • 2005
  • In this study, to prove the effect of soybeans's electron donating ability and its addition on eel gouem, storage and sensory characteristics were examined. During the storage period, pH values of all gouem samples were decreased with initial increase except the control. BSB $3\%$ sample had the lowest pH value and YSB $10\%$ sample was the highest 6.71 in pH value at first storage day. The electron donating ability of soybeans were increased with the amount of addition. The electron donating ability of SBSB 20g sample was the highest, which was 2 ${\~}$ 3 times higher than that of YSB sample. L values of all the gouem samples had a tendency to decrease according to the storage period and amount of addition. All samples' a values were increased throughout the storage period, while b values decreased except the control and GNG sample. TBA and VBN values of all the samples were up and down throughout the storage period SBSB $10\%$ sample had the lowest in TBA value. The electron donating ability of all soybean samples and TBA value of eel gouem samples showed a negative correlation. Total plate count of bacteria was increased rapidly for initial storage period, but all samples showed a tendency of slow growth after the 8th day of storage. During all storage days, SBSB, BSB samples had a similar tendency of low total plate count growth. GNG $10\%$ sample showed the lowest in total plate count of bacteria at sixteenth day of storage. Sensory scores of all samples decreased with storage. For all the items of the sensory evaluation, SBSB $5\%$ sample got the highest score among all eel gouem samples. GNGSB sample showed the lowest in TBA value and total plate count of bacteria. And in the sensory evaluation, GNGSB sample got the highest scores for several items.

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Clostridium butyricum NCIB 9576에 의한 당으로부터 혐기적 수소생산 (Hydrogen Gas Production by Fermentation from Various Sugars Using Clostridium butyricum NCIB 9576)

  • 김미선;문광웅;이인구;이태진;성창근
    • 한국미생물·생명공학회지
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    • 제27권1호
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    • pp.62-69
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    • 1999
  • Clostridium butyricum NCIB 9576 evolved hydrogen gas and produced various organic acids from glucose, lactose, starch, and glycerol. Total amount of hydrogen gas produced from 1 and 2% glucose were 630 and 950ml $H_2$/l-broth, respectively, for the first 24 hrs of incubation and the maximum hydrogen production rates were 42 and 94ml $H_2$/hr/1-broth, respectively. Teh initial pH 6.8 decreased to 4.2~4.5 during the first 12~16 hrs of fermentation when the pH was not controlled, resulting in ceasing the cell growth and hydrogen evolution and in degradation of 82 and 40% glucose after 24hrs of incubation from 1 and 2% glucose, respectively. When pH was controlled to 5.5, glucose was consumed completely and resulted in increasing hydrogen production approximately 38~50% compared to the experiments without the pH control. C. butyricum NCIB 9576 produced hydrogen gas approximately 644, 1,700 and 3,080 ml $H_2$/l-broth with 0.5, 1 and 2% lactose, respectively and the maximum hydrogen production rates were 41, 141 and 179ml $H_2$/hr/l-broth, respectively. All of the lactose added was degraded completely during fermentation even though pH was not controlled. C. butyricum NCIB 9576 produced 183 and 709ml $H_2$/l-broth with 0.1 and 0.5% starch for 48 hrs, respectively, when pH was not controlled. The maximum rates of hydrogen gas production were 43 and 186ml $H_2$/l-broth, respectively and 80~100% of starch added was fermented. Approximately 107ml $H_2$/l-broth was produced using 1% glycerol by C. butyricum NCIB 9576 and the pH was maintained higher than 6.1 during fermentation without pH control. The degradation of glucose, lactose, starch and glycerol by C. butyricum NCIB 9576 were affected by the pH of fermentation broth and the organic acids released during fermentation. The pH of feremtntation broth dropped to 4.2~4.6 after 12~14 hrs incubation when glucose was used as a substrate while pHs were maintained above pH 5 under the same experimental conditions when lactose, starch and glycerol were used. The organic solvents and acids produced during glucose fermentation were mainly ethanol, butyrate, acetate and a little of propionate, while butyrate was the main organic acids during the lactose, starch, and glycerol fermentation by C. butyricum NCIB 9576.

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약용식물 추출물이 냉면육수에 미치는 영향 (Effects of Medicinal Plants Extract on Naengmyeon Broth)

  • 김명숙;최윤희;홍선표
    • 한국식품영양학회지
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    • 제16권4호
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    • pp.328-333
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    • 2003
  • 산내, 화초, 정향, 소회향의 약용식물을 추출하여 냉면육수에 0.1%와 0.3%의 농도로 첨가했을 때 저장기간 동안 냉면육수에 미치는 영향을 살펴본 결과 육수의 pH는 이들 약용식물 처리군 중 산내 첨가군이 가장 효과적으로 무첨가군이 pH 4.60일 때, 0.1%와 0.3% 첨가시 각각 pH 4.92, pH 5.08이었다. 적정산도는 저장기간 48시간 이후부터는 산도가 현저히 낮아짐을 볼 수 있었는데, 산내의 측정치가 저장기간 90시간에 무첨가군이 0.89%일 때 0.1%첨가와 0.3% 첨가시 각각 산도 0.66과 0.55로 가장 낮았고, 다음으로 화초, 정향, 소회향 순으로 낮은 값을 보였다. 탁도는 처음에는 약용식물 첨가군이 0.1% 첨가시 7.5∼7.9, 0.3% 첨가시 7.9∼8.2였고, 무첨가군이 7.1이었다. 90시간 경과 후에는 무첨가군인 10.8, 약용식물 첨가군은 0.1%와 0.3% 첨가군이 각각 8.8∼9.5, 8.7∼9.0으로 더 낮은 값을 나타내었다. 총균수 및 대장균수는 저장기간 72시간째에 무첨가군에서 급격히 균이 증가하였고, 산내가 가장 효과적인 억제를 보였는데, 즉 총균수는 72시간째에 무첨가군이 4.8${\times}$10 CFU/ml 일 때, 0.1% 첨가시 1.7${\times}$10 CFU/ml, 0.3% 첨가시 0.9${\times}$10 CFU/ml 이었다. 대장균수는 72시간째에서는 무첨가군이 6.0 ${\times}$ 10 CFU/ml 일때, 0.1% 첨가시 3.2${\times}$10 CFU/ml, 0.3% 첨가시 1.7${\times}$10CFU/ml 이었고, 저장기간 90시간째에는 무첨가군이 6.0 ${\times}$ 10 CFU/ml 일 때 0.1% 첨가시 3.1${\times}$10 CFU/ml, 0.3% 첨가시 1.7${\times}$10 CFU/ml 로 측정되었고, 산내에 이어 화초, 정향, 소회향 순으로 효과를 나타내었다. 휘발성 염기질소량은 가장 낮은 측정치를 보인 산내의 경우 처음에 무첨가군이 2.67mg%일 때, 0.1%와 0.3% 첨가시 각각 2.58mg%, 2.47mg%이었고, 90시간 후에는 무첨가군이 3.96mg% 일 때, 0.1%와 0.3% 첨가시 각각 3.64mg%, 3.33mg%를 나타내었다. 이상의 냉면육수의 저장성 향상을 위한 산내, 화초, 정향, 소회향의 4가지 약용식물을 첨가하여 저장기간 중의 변화를 살펴본 결과 산내추출물을 첨가했을 때 가장 효과적이었으며, 저장기간 3일 이후에 항균효과가 뚜렷이 나타남을 확인하였다.

AN INVESTIGATION OF IMMUNIZATION AGAINST SOMATOSTATIN BY MEASURING ANTIBODY TITRES, SOMATOSTATIN AND SOMATOTROPIN PROFILES IN GILTS

  • Du, Z.L.;Hacker, R.R.
    • Asian-Australasian Journal of Animal Sciences
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    • 제6권2호
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    • pp.211-218
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    • 1993
  • The effect of active immunization against porcine somatostatin (SRIF-14) on somatostation and somatotropin secretion profile in 18 gilts was investigated. Gilts were assigned to the following treatments: control (sham injection, n = 6); bovine serum albumin (BSA) (injection of BSA with bacterial protein adjuvant, n = 6); SRIF (injection of BSA-SRIF-14 conjugate with bacterial protein adjuvant n = 6). Serum SRIF and pST were assayed from the blood samples taken on day 7 after the last immunization injection. Anti-SRIF antibody titres were assayed in weekly samples two weeks after the initial immunization to one week after the last immunization. Results revealed that the immunization protocol used in the present investigation failed to produce antibodies capable of neutralizing endogenous somatostatin. In addition, the porcine somatotropin assay revealed no significant differences in baseline pST concentration, mean peak amplitude and number of peaks during a 24 h secretory period among SRIF, BSA and control treatment. There were also no differences in SRIF baseline concentration, peak amplitude, and number of peaks during a 24 h secretory period among any of the three treatments. Circulating concentrations of pST and pSRIF were highly correlated (r = -0.09). Furthermore, anti-SRIF antibody titre was not detected in the serum of the gilts actively immunized against SRIF. These data, collectively, suggest that the protocol employed in the present investigation for active immunization against SRIF is not an effective method for changing SRIF and pST secretion profiles of the gilt and thus to enhance performance.

국내 시판 중인 일부 과일 리큐어의 치아 부식능 평가 (Erosive potential of several fruit-flavored liquors in Korea)

  • 박석우;김상겸;정은하;권호근;김백일
    • 대한치과의사협회지
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    • 제54권7호
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    • pp.521-528
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    • 2016
  • Purpose: The aim of this study was to evaluate the erosive potential of several fruit-flavored liquors marketed in Korea by measuring pH, titratable acidity, and variations in pH utilizing an ISO method. Materials and Methods: Six fruit-flavored liquors were investigated. An orange juice and three kinds of soju were selected as the control beverage. The pH and titratable acidity of the beverages were determined by 1 M NaOH until the pH 5.5 and 7.0 (recorded as $TA_{5.5}$ and $TA_{7.0}$, respectively). All measurements were performed in triplicate. The process of ISO 28888 was used for measurement of the pH variation (${\Delta}pH$) using an under-saturated hydroxyapatite solution (screening solution) and determining the difference between the initial and final pH of the screening solution. The average ${\Delta}pH$ was determined based on 4 measurements. Results: All the fruit-flavored liquors tested in this study showed a pH lower than the critical pH for dental erosion (4.5). The average pH of the fruit-flavored liquors was 2.77 and was also lower than the pH of the soju and an orange juice (control drinks). $TA_{5.5}$ and $TA_{7.0}$ values of the fruit-flavored liquors were 4.92ml and 7.13ml, respectively. The fruit-flavored liquors showed an erosive potential capable of damaging the enamel surfaces, whereas the orange juice had the highest titratable acidity. The changes in pH determined using the screening solution confirmed that the fruit-flavored liquors had erosive potential, with ${\Delta}pH$ value of 1.53. Conclusions: The fruit-flavored liquors tested in this study might have a strong potential to erode dental hard tissues.

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