• Journal of Environmental Science International
• /
• v.5 no.1
• /
• pp.43-50
• /
• 1996

Thiobacillus neopolitanus R-10, which produces a active thiosulfate oxidase was isolated from nightsoil. The optimal culture conditions of Thiobacillus neopolitanus R-10 for the production of enzyme was determined as followed: 0.8% $Na_2S_2O_3$, 0.2% $KH_2PO_4$, 0.2% $K_2HPO_4$, 0.04% $Na_2CO_3$, 0.02% $MgSO_4$.$7H_2O$, 2ml trace elements solution, ann PH 6.5 at 3$0^{\circ}C$ and 72hr cultivation. The oxidase was successively purified 83 folds yield by ${(NH_2)}_2SO_4$ fractionation, DEAE-Cellulose, Sephadex A-50 column chromatogrophy and gel Sephadex G-150 gel filteration with yield of 5.9%. The molecular weight of purified enzyme was estimated to be 43.000 dalton by SDS-polyacrylamide gel electrophoresis and gel filteration column chromatography The enzyme activity was highest at 40t and PH 7.0 The enzyme activity was relatively high by $\beta$-mercaptoethanol but strongly inhibited by cysteine.

• 수도
• /
• s.66
• /
• pp.90-107
• /
• 1994

일반 정수시설의 설계는 15년 이전경까지는 기성의 기본 Pattern에 따라서 토목기사에 의해서 행해져 왔고 괄목 할만한 변화는 보이지 않았다. 그러나 최근은 살균처리에 따른 부생성물의 발암성에 대한 공포 때문에 미국의 EPA는 음료수의 허용수질의 대폭 개정을 행함과 동시에 살균제, 살균처리의 기준, 발암성이 의심스러운 물질량의 제한, 여과수 탁도의 저감, 급수관의 부식을 방지하기 위한 정수 수질의 조정 등을 공공 수도에 의무화했다. 따라서 이와 같은 조건을 만족시키는 정수처리 계통과 그에 따르는 계장 시설과 정수관리가 필요하며, 화학, 화학 공학, 미생물학, 계장공학 등의 넓은 분야의 전문 지식이 토목 공학에 첨가해서 필요하게 되었다.

• Proceedings of the Korean Fiber Society Conference
• /
• 2003.10b
• /
• pp.271-272
• /
• 2003

Electrospinning is a novel process for forming fibers with submicron scale diameters through the action of electrical force. In the previous study, we performed study on the ultrafine PVDF nanofiber production in the stable spinning condition. Recently it would be great interest to fabricate IP(inorganic particle) assemblies in nanofibe. since such IP/nanofiber hybrid materials might be used in a nonwoven form as nanowires, medical gauges for bums healing and cell growing, sensors, chemical and gas filteration. (omitted)

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.20 no.4
• /
• pp.274-281
• /
• 2010

The objectives of this study are (a) to investigate the distribution patterns and exposure concentrations of biological agents in sawmill industries and (b) to compare sampling methods of biological agents. The representative processes of 5 sawmills were selected to measure total airborne bacteria, fungi, endotoxin as well as dust. Airborne bacteria and fungi were measured with one stage impactor, six stage impactor and gelatin filteration methods. Endotoxin was collected with polycarbonate filters and analysed by kinetic chromogenic Limulus Amebocyte Lysate method. Geometric mean levels of airborne bacteria, fungi, endotoxin and dust were 1,864 CFU/$m^3$, 2,252 CFU/$m^3$, 31.5 EU/$m^3$ and 2.4 mg/$m^3$. The ratios of indoor/outdoor concentrations were 3.7 for bacteria, 4.1 for fungi, 3.3 for endotoxin and 9.7 for dust. The respiratory fractions of bacteria were 68.0, 50.9, 49.2 and 45.1% in band-saw, table-saw, rip-saw process and outdoor air. The respiratory fractions of fungi were 78.7, 90.8, 87.5 and 84.8% in band-saw, table-saw, rip-saw process and outdoor air, respectively. There was no significant differences in bacterial concentrations among single stage, six stage impaction and filteration methods. But, fungal concentrations measured with filtration methods were significantly higher than those with impaction methods. Geometric mean levels of airborne bacteria and fungi were higher than the OSHA guideline values of 1,000 CFU/$m^3$. The respiratory fractions of fungi were above 75%. The concentrations of biological agents were significantly different among culture-based sampling methods. In the exposure assessments of biological agents, further studies are needed for the comparisons of diverse sampling methods and the investigations of environmental factors.

• Current Research on Agriculture and Life Sciences
• /
• v.7
• /
• pp.109-116
• /
• 1989

This study was carried out to confirm the agent responsible for the antibacterial activity in milk culture or Lactobacillus bulgaricus to extract and purify it. The following results were summarized as followings : The antibacterial agent was extracted from the cultured skim milk with methanol and acetone and was purified by Sephadex G-50 gel filteration and thin layer chromatography on silica gel. The antibacterial substance other than lactic acid was confirmed by turbidimetric technique using the neutralized culture filtrate which inhibited the growth of Bacillus subtilis. The purified agent showed inhibitory activity against Bacillus subtilis, Escherichica coli, Pseudomonas fluorescens Staphylococcus aureus, Proteus vulgaris and Shigells $dysenteria^2$. The agent obtained from thin layer chromatography was free from $H_2O_2$ or lactic acid.

• Microbiology and Biotechnology Letters
• /
• v.26 no.5
• /
• pp.379-386
• /
• 1998

Deterioration of food is in general caused by the presence of microorganisms and chemical compounds of food itself. There exists antimicrobial compound in the food, however, addition of food antiseptics, additives, or physico-chemical processing is a common practice. The safety of artificial chemical antiseptics became a serious public concern, therefore, new natural antiseptic compounds are in need to be developed. We have isolated a new natural antifungal protein (KBS-B2) from Astragal seed through ammonium sulfate precipitation and column chromatography using FPLC Mono-S and Superose 12HR. The purified protein inhibited growth of Candida albicans, and spore germination of food spoiling fungi such as Aspergillus ochraceus, Penicillium expensum, P. digitatum and Botrytis cineria. Antifungal effect of the KBS-B2 protein could be directly assayed by bioautography overlaying the fungal spores on the electrophoresed acrylamide gel. The comparison of N-terminal amino acid sequences of the KBS-B2 with known antifungal protein revealed that had 50% homology to thaumatin and zeamatin like proteins.

• Journal of Nutrition and Health
• /
• v.33 no.6
• /
• pp.625-631
• /
• 2000

The purpose of this study was to investigate the effects of vitamin E on the oxidative damage and glomerular filteration rates(GFR) of kidney in streptozotocin(STZ) induced diabetic rats. Sprague-Dawley male rats weihing 100$\pm$10gm were randomly assigned to one normal and three STZ-induced diabetic groups which were subdivided into vitamin E free diet(DM-0E group)40mg vitamin E per kg diet(DM-40E group) and 400mg vitamin E per kg diet (DM-400E group), Vitamin E level of normal group was 40mg per kg diet. diabetes was experimentally induced by intravenous injection of 55mg/kg of body weight of STZ in citrate buffer(pH 4.3) after 4 weeks feeding of experimental diets. Animals were sacrificed at the 6th day of diabetic states. Activities of xanthine oxidase(XOD) in DM-0E DM-40 and DM-400E groups were significantly increased by 133%, 110%, and 74% respectively compared to normal group. The contents of microsomal superoxide radical(O2) in kidney were 106% and 119% higher of DM-0E and DM-40E groups than normal group respectively but that of DM-400E group was similar to normal group. The level of urnary microalbumin in DM-0E group was increased as 5 times much as normal group at the 6th day. Those of DM-40E and DM-400E groups were decreased to 16% and 36% respectively compared to DM-0E group. The content of urinary $\beta$2-microglobulin in DM-0E DM-40E and DM-400E group were increased by 268%, 181% and 163% respectively compared to normal group. GFR in DM-0E and DM-40E were significantly increased but was nor significantly different from DM-400E groups compared to normal group. In conclusion the supplementation of dietary vitamin E reduced peroxidative damage of renal glomerular and renal dysfunction in diabetic rats.

• Journal of Life Science
• /
• v.19 no.3
• /
• pp.373-377
• /
• 2009

Poliovirus, coxsackievirus, and ecovirus isolates from environmental sources were compared with laboratory strains to determine their removal rate in the water treatment process. The recovery efficiencies of poliovirus, coxsackievirus and echovirus using positive strains ranged from $72{\sim}108%$. Regarding virus removal efficiency in water treatment of pilot-plants, about 99% of all of the viruses were removed in the sedimentation step and 100% of viruses were clearly removed through post-ozonation and BAC filteration. Using six cell lines tested viral sensitivity in cell line and showed different sensitivity as viruses. Polioviruses showed higher sensitivity in the BGMK cell line than other cells, and coxsackieviruses were detected in higher level in the BGMK and Vero cell lines. On the other hand, the RD cell line was useful in the isolation of ecoviruses.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.20 no.4
• /
• pp.273-281
• /
• 1987

In this work the antioxidant effects of browning reaction products prepared by xylose-tryrtophan reaction system were discussed. The antioxygenic brown pigments were separated by solvent extraction, and column chromatography and isolated by gel filteration. The functional groups of the brown pigments which had antioxidant activity were examined. The brown pigments extracted with methanol showed antioxidant effect and were fractionated in 5portions on DEAE-cellulose column. The elutes with methanol: acetic acid(10:30 v/v sol n(A), methanol: chloroform(95:5 v/v) sol n(C), and chloroform: acetic acid(10:30 v/v) sol n(E) only showed antioxidant activity and their compositions were 22.43, 21.51 and $34.43\%$ respectively. When each fraction on DEAE-cellulose column was reseparated on Sephadex LH-20 column, 2 fractions were obtained from portion A and C respectively. Molecular weights of A, C and E fraction of brown pigments were from 2,600 to 3,700. By elucidation of IR spectra, the pigment fractions which showed a strong antioxidant activity were tearing the indole group. It is suggested that the antioxidant function of the brown pigment is due to hydroxy and amino group. A higher activity of the brown pigment fraction E might be attributed to carboxylic acid or carboxylic ester compounds.

• Food Science and Preservation
• /
• v.4 no.3
• /
• pp.301-309
• /
• 1997

This study was conducted to examine morphological characteristics and the content of cell wall polysaccharides of Brassica campestris var. pekinensis(baechu). First of all, the variety of scientific name and naming of parts of baechu in the literatures of kimchi showed, which will unify marks. So, we propose not so much mid-rib and leaf blade of baechu leaf as white part and green part, respectively. On the other hand, the forms of vessel elements of white part in baechu consist in ring, sclariform and reticulate thickening. The proximate compositions and contents of cell wall polysaccharides of baechu has significant differences between its cultivars. The cell wall pectin from baechu exhibited four peals with molecular weights of 2,000,000, about 100,000 and less than 10,000 by gel filteration chromatography and hemicellulose did two peaks with molecular weights of 2,000,000 and 10,000.