• Applied Chemistry for Engineering
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• v.19 no.2
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• pp.168-172
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• 2008

Not all types of soil occurring on household fabrics can be removed by simple washing with normal surfactants. In order to achieve a satisfactory cleaning effect, an additional treatment step, called bleaching, is required in such cases. Currently, the best known bleach activator is tetraacetylethylenediamine (TAED). In this study, we synthesized a novel organic bleach activator (OBA), decanoyloxyethoxycarbonyloxybenzenesulfonate. For stabilizing the OBA, it was coated with zeolite and polyethylene glycol. It is found that the stability was enhanced and OBA shows good cleansing and bleaching effects even in cold water ($20^{\circ}C$). OBA also shows easy biodegradability with 88% in the condition of OECD standard. During the cleansing process, OBA shows excellent microbiological effect against T. mentagrophytes and S. aureus.

• Journal of Korean Medicine Rehabilitation
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• v.30 no.1
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• pp.31-45
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• 2020

Objectives In this study, we investigated the antimicrobial activity of a 70% ethanol extract of Maneung-hwan (MEH), which is prescribed by practitioners of oriental medicine for use against methicillin-resistant Staphylococcus aureus (MRSA). Methods The antibacterial activity of MEH against MRSA strains was evaluated using the disc diffusion method, broth microdilution method (minimal inhibitory concentration, MIC), checkerboard dilution test, and time-kill test. The mechanism of action of MEH was investigated by bacteriolysis using detergents or ATPase inhibitors Additionally, mRNA and protein expression were investigated by quantitative reverse transcription-polymerase chain reaction and western blot assay, respectively. Results The MIC of MEH was 25~1,600 ㎍/mL against all the tested bacterial strains. We showed that MEH extract exerts strong antibacterial activity. In the checkerboard dilution test, the fractional inhibitory concentration index of MEH in combination with antibiotics indicated synergism or partial synergism against S. aureus. The time-kill study indicated that the growth of the tested bacteria was considerably inhibited after a 24-h treatment with MEH and selected antibiotics. To measure the cell membrane permeability, MEH (3.9 ㎍/mL) was combined with Triton X-100 (TX) at various concentrations N,N-dicyclohexylcarbodimide (DCCD) was also tested as an ATPase inhibitor. TX and DCCD cooperation against S. aureus exhibited synergistic action. Accordingly, the antimicrobial activity of MEH in the context of cell membrane rupture and ATPase inhibition was assessed. Additionally, the expression of genes and proteins associated with resistance was reduced after exposing MRSA to MEH. Conclusions These results suggest that MEH possesses antibacterial activity and acts as a potential natural antibiotic against MRSA.

• Korean Journal of Microbiology
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• v.41 no.1
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• pp.47-52
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• 2005

This study was carried out to identify bacterial strains adhered to human scalp hair and to investigate the antibiotic susceptibility of them. A total of 39 isolates were obtained from patients in intensive care units and healthy persons. The most common species isolated was Staphylococcus epidermidis (19 isolates), followed by S. aureus (14 isolates), S. waneri (5 isolates), and S. pasteuri (1 isolate). The susceptibility of isolates to amikacin, ampicillin, bacitracin, carbenicillin, cefazolin, cefoperazone, chloramphenicol, erythromycin, gentamicin, methicillin, nalidixic acid, neomycin, oxacillin, penicillin, streptomycin, tetracycline and vancomycin was determined by the disk diffusion method. All of the antibiotic resistant isolates were obtained from patient scalp hair. To examine the effect of conventional shampoo and detergent SDS on removing of bacteria from hair, we treated hair with culture solution of S. aureus. The bacteria attached to hair were not removed even by repeated washing with detergents. These results suggested that hair could be a source of bacterial contamination in hospital.

• Journal of Microbiology and Biotechnology
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• v.22 no.3
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• pp.331-338
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• 2012

A novel gene coding for an endo-${\beta}$-1,4-mannanase (manA) from Bacillus subtilis strain G1 was cloned and overexpressed in P. pastoris GS115, and the enzyme was purified and characterized. The manA gene consisted of an open reading frame of 1,092 nucleotides, encoding a 364-aa protein, with a predicted molecular mass of 41 kDa. The ${\beta}$-mannanase showed an identity of 90.2-92.9% ${\leq}95%$) with the corresponding amino acid sequences from B. subtilis strains deposited in GenBank. The purified ${\beta}$-mannanase was a monomeric protein on SDS-PAGE with a specific activity of 2,718 U/mg and identified by MALDI-TOF mass spectrometry. The recombinant ${\beta}$-mannanase had an optimum temperature of $45^{\circ}C$ and optimum pH of 6.5. The enzyme was stable at temperatures up to $50^{\circ}C$ (for 8 h) and in the pH range of 5-9. EDTA and most tested metal ions showed a slightly to an obviously inhibitory effect on enzyme activity, whereas metal ions ($Hg^{2+}$, $Pb^{2+}$, and $Co^{2+}$) substantially inhibited the recombinant ${\beta}$-mannanase. The chemical additives including detergents (Triton X-100, Tween 20, and SDS) and organic solvents (methanol, ethanol, n-butanol, and acetone) decreased the enzyme activity, and especially no enzyme activity was observed by addition of SDS at the concentrations of 0.25-1.0% (w/v) or n-butanol at the concentrations of 20-30% (v/v). These results suggested that the ${\beta}$-mannanase expressed in P. pastoris could potentially be used as an additive in the feed for monogastric animals.

• Journal of the Korean Applied Science and Technology
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• v.12 no.1
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• pp.47-54
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• 1995

Water pollution, which is caused by surfactants, is increased by insolubility and excessive uses of detergents. The detergency properties of nine kinds of amphoteric surfactants derived from imidazoline were investigated and compared with sodium lauryl sulfats(SLS) of petrochemical surfactant by using detergent formulations. Several physico-chemical properties were measured to investigate the effective factors on detergency. From the comparision of these compounds with SLS, it was found that 1-(2-hydroxyethyl)-1- (3-sulfonatedpropyl)-2-undecyl-2-imidazolinum [IV] has the most outstnading characteristics of detergency and various fundamental properties. Therefore, this result is expected to do its environmental stability as a nonpolluting detergent. Detergency process of surfactants were discussed in relation to physico-chemical treatments. Performance improvement on detergency is made work of adhesion to soil as small as possible. Therefore these results show that contamination is easily removed and industrial applications may be respected.

• KSBB Journal
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• v.24 no.2
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• pp.140-148
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• 2009

The microbial biosurfactants can be substituted to the chemical detergents in some industrial processes. In this study we developed a biotechnological processes for the biosurfactants with microorganisms. The biosurfactants have a lot of advantages in comparision with the chemical surfactants. They are proenvironmental even during and after industrial use. But there are not so many kinds of biosurfactants. The production cost and the end price is much higher than the chemical surfactants. But nowdays there are many kinds of microorganisms, which can produce the surfactants in large quantity and fast. We tried to develop a production process for the large scale with some microorganisms. At first Candida bombicola KCTC 7145, Sphingomonas chungbukensis KCTC 2955 and Sphingomonas yanoikuyae KCTC 2818 are cultivated and studied. For the large scale production process we used molasses as a complex medium and tried to optimize the process. Molasses contains 17 to 25% of water, 45 to 50% of sugar and 25% of carbohydrate, it can be fully used as a substrate. The microorganisms have been cultivated in the diluted media with molasses 2, 5, 8 and 10%, respectively, The optimal conditions for the cultivation and the production process have been studied. For the study the optical density, glucose concentration and the surface tension were measured. Candida bombicola KCTC 7145 and the 5% molasses media was selected as an optimal condition for the production process of a biosurfactant. During cultivation of Candida bombicola KCTC 7145 in the 5% molasses medium kerosene and corn oil were added for promoting the biosurfactants.

• Fashion & Textile Research Journal
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• v.22 no.4
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• pp.534-539
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• 2020

Experimental research is needed to provide information on the removal of bloodstains since washing clothes contaminated with blood is necessary for medical related fields (such as ambulance workers and doctors) as well as for women of childbearing age. This study investigated efficient washing conditions for the removal of bloodstains with a focus on washing temperature, fiber type and blood ageing time. Polyester/cotton fabric showed the highest detergency from among three fabrics that were influenced by the composition of the fiber and the structure of the yarn and fabric. When examining the effect of detergent, it was concluded that the alkalinity over pH 10 was essential to remove bloodstains and that auxiliary agents such as soil antiredeposition agents and bleach had a significant effect on the removal of bloodstains. Washing temperature showed the highest detergency at 20℃ due to the activity of the enzyme without the denaturalization of blood. Blood-ageing influenced detergency by inducing changes in the adsorption area and chemical bond. A combination of methods such as quick removal after contamination, use of alkaline detergents including soil antiredeposition agents and bleach, and low-temperature washing could help remove bloodstains.

• Safety and Health at Work
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• v.8 no.1
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• pp.105-115
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• 2017

Background: The goal of this study is to develop a general population job-exposure matrix (GPJEM) on asbestos to estimate occupational asbestos exposure levels in the Republic of Korea. Methods: Three Korean domestic quantitative exposure datasets collected from 1984 to 2008 were used to build the GPJEM. Exposure groups in collected data were reclassified based on the current Korean Standard Industrial Classification ($9^{th}$ edition) and the Korean Standard Classification of Occupations code ($6^{th}$ edition) that is in accordance to international standards. All of the exposure levels were expressed by weighted arithmetic mean (WAM) and minimum and maximum concentrations. Results: Based on the established GPJEM, the 112 exposure groups could be reclassified into 86 industries and 74 occupations. In the 1980s, the highest exposure levels were estimated in "knitting and weaving machine operators" with a WAM concentration of 7.48 fibers/mL (f/mL); in the 1990s, "plastic products production machine operators" with 5.12 f/mL, and in the 2000s "detergents production machine operators" handling talc containing asbestos with 2.45 f/mL. Of the 112 exposure groups, 44 groups had higher WAM concentrations than the Korean occupational exposure limit of 0.1 f/mL. Conclusion: The newly constructed GPJEM which is generated from actual domestic quantitative exposure data could be useful in evaluating historical exposure levels to asbestos and could contribute to improved prediction of asbestos-related diseases among Koreans.

• Korean Journal of Clinical Laboratory Science
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• v.42 no.1
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• pp.22-31
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• 2010

The most common sources of biological trace material which are found in crime scene are the human bloodstains. Reliable identification in the forensic casework is important as it provides crucial insights into crime scene reconstruction and can thus contribute towards solving crimes. Blood-stains are routinely tested in forensic practise using various methods including the leucomalachite green (LMG) test, Kastle-Meyer phenolphthalein test, tetramethylbenzidine test, orthotolidine test, or the luminol chemoluminescence test with the latter cleaning attempts. All these presumptive thus indicative but not identifying tests take advantage of the peroxidase-like activity of the heme unit of the hemoglobin molecule in human blood. Therefore, false-positive results can be caused by the presence of strong oxidants, such as chlorine-containing detergents or by true peroxidases (e.g., from plants). In this study, composition for Gum guaiac was evaluated for the forensic identification of bloodstain and compared with the LMG. The sensitivity and specificity of the composition for Gum guaiac were examined more stable in bloodstain. The positive of Composition for Gum guaiac shown even with the 100,000-fold diluted bloodstain, which was no difference in comparison with LMG test. It was shown that composition for Gum guaiac was very stable to resist boiling for 20 minutes and the effect of bacteria did not affect the genetic analysis as well. The above result of the crime scene investigation, composition for Gum guaiac is easily expected to help identifying bloodstain in the evidences.

• Journal of Microbiology and Biotechnology
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• v.12 no.2
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• pp.189-195
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• 2002

Using Streptomyces sp. YU100 isolated from Korean soil, the fermentative production of phospholipase D was attempted along with its purification and characterization studies. When different carbon and nitrogen sources were supplemented in the culture medium, glucose and yeast extract were found to be the best. By varying the concentration of nutrients and calcium carbonate, the optimal culture medium was determined as 2.0% glucose, 1.5% yeast extract, 0.5% tryptone 0.3% calcium carbonate. During cultivation, the strain secreted most of the phospholipase D in the early stage of growth within 24 h. The phospholipase D produced in the culture broth exhibited hydrolytic activity as well as transphosphatidylation activity on lecithin (phosphatidylcholine). In particular, the culture broth showed 8.7 units/ml of hydrolytic activity when cultivated at $28^{\circ}C$ for 1.5 days. The phospholipase D was purified using 80% ammonium sulfate precipitation and DEAE-Sepharose CL-6B column chromatography, which produced a major band of 57 kDa on a 10% SDS-polyacrylamide gel with purity higher than 80%. The enzyme showed an optimal pH of 7 in hydrolytic reaction, and at pH 4 in a transphosphatidylation reaction. The enzyme activity increased until the reaction temperature was elevated to $60^{\circ}C$. The enzyme was relatively stable at high temperatures and neutral pH, but significantly unstable in the alkaline range. Among the detergents tested as emulsifiers of phospholipids, the highest enzyme activity was observed when 1.5% Triton X-100 was employed. However, no inhibitory effect by metal ions was detected. Under optimized reaction conditions, the purified enzyme not only completely decomposed PC to phosphatidic acid within 1 h, but also exhibited higher than 80% conversion rate of PC to PS by transphosphatidylation within 4 h.