Yoon-Jung Kwon

Effect of pineapple protease on the characteristics of protein fibers

A pineapple protease, bromelain, was used to improve the dyeing properties of protein fibers such as wool and silk. The optimal condition for the activity of the pineapple protease was about 60 °C at pH 7. The wool and silk were treated with the protease extracted from a pineapple and the K/S values of the dyed wool and silk were measured using a spectrophotometer in order to compare the dye uptake. The protease treatment enhanced the dyeing properties of protein fibers without severe changes in mechanical properties. The surface appearances of protease-treated fibers were observed by microscopy.

Soil Bioconsolidation Through Microbially Induced Calcite Precipitation by Lysinibacillus sphaericus WJ-8

ABSTRACT Biomineralization is a process that leads to the formation of minerals via a biologically or biotechnologically mediated route. This process is a new and innovative research area in geotechnological engineering and structural engineering because it has wide-ranging implications for the strengthening of soil, sand, stone, and cementitious materials. In the present study, we demonstrated the ability of Lysinibacillus sphaericus WJ-8 to precipitate 15.3 mg/mL of calcite and to degrade 415 μmol/mL of urea over a 120-h period. The cell surface hydrophobicity and sand adhesion of spores were higher than those of vegetative cells (77.2% vs. 24.0% and 54.1% vs. 7.8%, respectively). In addition, the bioconsolidated soil block samples had significantly smaller pores than did the control soil block samples. Scanning electron microscopy and energy dispersive spectroscopy analysis revealed that calcite crystals were frequently formed in the bioconsolidated soil block samples, but did not occur in the control soil block samples. In addition, sharp peaks in the X-ray diffraction spectra indicated that calcite (CaCO3) crystals constituted the predominant mineral in the bioconsolidated samples, whereas quartz (SiO2) crystals constituted the predominant mineral in the control samples.

Alkaline weight reduction monitoring of sea-island type polyamide microfiber fabrics

The alkaline dissolution behavior of sea-island type polyamide microfibers were successfully monitored using a cationic dye staining method. Weight reduction behavior of the alkali-treated microfiber fabrics and the treated fabrics stained with cationic dye were investigated in a comparative manner. The termination of dissolution monitored by both methods was also confirmed by scanning electron microscopy.

Use of protease produced byBacillus sp. SJ-121 for improvement of dyeing quality in wool and silk

In this study, a microorganism-produced protease was used to improve the quality of fabrics. First, the protease-producing bacteria were isolated from soils, and one of them was selected and identified asBacillus sp. SJ-121. The optimal medium composition for its growth and protease production was determined to be as follows: glucose 1 g/L, soybean meal 0.5 g/L, soy peptone 0.5, K2HPO4 0.2, MgSO4·7H2O 0.002, Nacl 0.002, and Na2CO3 g/L. Also, the optimal temperature for the production of the protease byBacillus sp. SJ-121 was about 40°C at pH 7. The wool and silk were treated with the protease fromBacillus sp. SJ-121. Follwoing the protease treatment, changes in the surface of a single yarm of the fabrics were observed by both an optical microscope and a scanning electron microscope (SEM). Changes in the K/S value of the wool and silk were measured by spectrophotometric analysis, in order to determine the amount of dye uptake in the fabrics. We also performed a tensile strength examination in order to determine the degree and nature of mechanical changes in single yarns of the wool and silk fabrics. By increasing the protease treatment time to 48h, the dyeing characteritics of the fabrics were enhanced, and the surfaces of the single yarns of the fabrics became smoother, due to the removal of soil and scale in them. However, no mechanical changes were detected in the fabrics. Therefore, we suggest that proper treatment of the protease produced byBacillus sp. can improve the quality of silk and wool.

Anti-adipogenic effects of Corni fructus in 3T3-L1 preadipocytes

Obesity is the most common health problem in developed countries and is considered a significant risk factor for many major human diseases. The goal of the present study was to evaluate the inhibitory effect of herbal extracts on adipocyte differentiation in 3T3-L1 preadipocytes. We screened the extracts of 30 plants, used in traditional medicine to test their effects against obesity. Among the tested extracts, Corni fructus ethanolic extract (CFEE), significantly inhibited adipocyte differentiation by more than 80% in 3T3-L1 preadipocytes in a dose-dependent manner. The level of adipogenesis in the 3T3-L1 cells was measured by Oil Red O staining and the triglyceride content assay. Furthermore, CFEE inhibited adipocyte differentiation by suppressing the expression of the adipogenic transcription factors CCAAT/enhancer binding protein (C/EBP) and peroxisome proliferator-activated receptor (PPAR), as confirmed by reverse transcription-polymerase chain reaction (RT-PCR) analysis. These results suggest that CFEE inhibits adipogenesis by suppressing the expression of adipogenic transcription factors.

Conditioning effect of a hair conditioner containing lugworm autolysate

A conditioner containing lugworm autolysate was prepared, and its feasibility as a new conditioner was investigated. The treatment of hair with the conditioner, before and after dyeing showed positive effects on the thickness, weight, and amino acid contents of the hair. These properties were significantly enhanced, and similar results were obtained by hair surface examination by using scanning electron microscopy and tensile strength measurements. The surface of the cuticles in the experimental group was smoother than that of the control group, and the arrangement of the hair scales was maintained even after shampooing for 20 times. The hair tensile strength of the experimental group was significantly higher than that of the control group. The significant treatment effect of the conditioner containing lugworm autolysate could be attributed to the synergistic effect of adhesive strength and effective film formation properties of lugworm autolysate.

Development of automated generation algorithm for skipped surface in die design

In general the design of exterior panel contains a number of faces composed of surfaces. It makes the design process repetitive and time-consuming task and entails errors or incompleteness such as skipped faces or discontinuity in the result. Furthermore those errors occurred in the design stage cause delay in the die design. In this paper, an algorithm to automate the tedious face work is proposed. The proposed algorithms not only automate the face work but also can reconstruct skipped surfaces or fix the discontinuous faces. The main advantages of the proposed algorithm are reduction of design lead time and to make die design process easier by generating the panel shape from one skin.

Heat adaptation improves viability of Lactococcus lactis subsp. lactis HE-1 after heat stress

We have studied the potential of environmental adaptation as a survival mechanism to enable lactic acid bacteria to withstand spray drying. The formulation process of these bacteria exposes them to stresses such as heating and dehydration on daily basis. In the present study, the effect of heat adaptation on subsequent exposure of Lactobacillus lactis subsp. lactis HE-1 cells to various types of lethal stress was examined by comparing the viability of heat-adapted cells with nonadapted ones. The responses of heat-adapted cells to other environmental stresses such as H2O2, heat, acid, and ethanol were also examined. The results showed that heat-adapted cells had a higher survival rate than the non-adapted cells. Morphological analysis was performed to explain the observed differences. The adaptation mechanisms in response to stresses in L. lactis subsp. lactis HE-1 are to be fundamental for survival during spray drying process.