• Microbiology and Biotechnology Letters
• /
• v.30 no.1
• /
• pp.63-67
• /
• 2002

Bifidobacterium strain was isolated from the feces of brast fed infants. The isolated strain was identified as Bifidobacterium longum by 16S rRNA sequence analysis and named as Bifidobacterium SH2. The MRS medium was modified to obtain high density cells of Bifidobacterium SH2. The optimal medium was determined to be 50 g/L lactose, 10 g/L beef extract, 10 g/L peptone, 5 g/L yeast extract, 7 g/L sodium acetate, 2 g/L ammonium citrate, 2 g/L disodium phosphate,1 g/L tween 80, 0.2 g/L MnSO$_4$ and 0.5 g/L L-cysteine. The pH and temperature were optimized as 5.0 and $37^{\circ}C$, respectively. Through out the optimization of medium composition and culture conditions, the dry cell weight and viable cell count were 2.5 times and 1.8 times higer than those in MRS medium, respectively.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.39 no.5
• /
• pp.544-555
• /
• 2002

The aim of this study is to develop the $^1H$-MRS data postprocessing software for both single-voxel and multi-voxel technique, which plays and important role as a diagnostic tool in clinical field. This software is based on graphical user interface(GUI) under windows operating system of personal computer(PC). In case of single-voxel MRS, both of raw data in time-domain and spectrum data in frequency-domain are simultaneously displayed in a screen. Several functions such as DC correction, zero filling, line broadening, Lorentz-Gauss filtering and phase correction, etc. are included to increase the quality of spectrum data. In case of multi-voxel analysis, spectroscopic image reconstructed by 3-D FFT was displayed as a spectral grid and overlapped over previously obtained T1- or T2-weighted image for the spectra to be spatially registered with the image. The analysis of MRS peaks were performed by obtaining the ratio of peak area. In single-voxel method, statistically processed peak-area ratios of MRS data obtained from normal human brain are presented. Using multi-voxel method, MR spectroscopic image and metabolite image acquired from brain tumor are demonstrated.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.6 no.5
• /
• pp.337-340
• /
• 2001

A galactooligosaccharide(GalOS)-producing yeast, OE-20 was selected from forty seven strains of yeast growing in Korean traditional Meju (cooked soybean) and the yeast was tentatively identified as Kluyveromyces maxianus var lactis by its morphology and fermentation profile. A maximum yield of 25.1%(w/w) GalOS, which corresponds to 25.1 g of GalOS per liter, was obtained from the reaction of 100 g per liter of lactose solution at 3$0^{\circ}C$, pH 7.0 for 18 h with an intracellular crude $\beta$-galactosidase. Glucose and galactosidase were found to inhibit GalOS formation. The GalOS that were purified by active carbon and celite 545 column chromatography were supplemented in MRS media and a stimulated growth was observed of some intestinal bacteria. In particular the growth rate of Bifidobacterium infantis in the GalOS containing MRS broth increased up to 12.5% compared to that of the MRS-glucose broth during a 48h incubation period.

• Microbiology and Biotechnology Letters
• /
• v.48 no.3
• /
• pp.287-295
• /
• 2020

Lactobacillus zymae GU240 was previously isolated from Kimchi, a Korean fermented vegetable, as a strong GABA producer. The strain showed β-galactosidase (β-Gal) activity on MRS agar plates with X-gal. When growth and β-Gal activities of GU240 were measured using MRS (glucose, 2%, w/v) and MRSL (lactose, 2%, w/v) broths, cells were found to grow slowly in MRSL, and the β-Gal activity (36 units at 4 h) was lower than that of cells grown in MRS (94 units at 16 h). The highest OD₆₀₀ value of the culture in MRS was 1.6 at 24 h at 37℃, whereas that of the culture in MRSL was 0.6 at 16 h. β-Gal activity of the culture in MRS reached the maximum (95.6 u/ml) at 16 h, decreased thereafter, and was not detected at 48 h. β-Gal activity for culture in MRSL reached its highest (36 u/ml) at 4 h and decreased gradually, but some activity (11.05 u/ml) still remained at 72 h. The structural gene encoding β-Gal in L. zymae GU240 was cloned as a 3.1 kb fragment, and DNA sequencing confirmed the presence of complete lacLM genes. lacLM genes from L. zymae GU240 showed 98-99% homologies in nucleotide sequences with other lacLM genes from L. brevis. Reverse transcription (RT)-PCR confirmed the operon structure of lacLM. The results indicated that L. zymae GU240 might be in the process of losing the ability to grow rapidly on lactose-containing medium, such as milk, due to adaptations to plant environments, including kimchi.

• Food Science of Animal Resources
• /
• v.31 no.2
• /
• pp.176-182
• /
• 2011

The bacteriocin-producing lactic acid bacteria Enterococcus faecium DB1 was isolated from Korean traditional gajami sikhae. Culture conditions were optimized by response surface methodology (RSM) to maximize bacteriocin DB1 production. E. faecium DB1 displayed the highest bacteriocin activity when grown in modified MRS medium containing sucrose, rather than glucose, as a carbon source. The effects of temperature, initial pH, and sucrose concentration were tested to determine the optimum conditions for maximum bacteriocin production by E. faecium DB1. A central composite design was used to control the three variables in the experiment. RSM revealed that the optimum values for bacteriocin production were 27.66 g/L sucrose, temperature of $34.37^{\circ}C$, and an initial pH of 6.54. A 2.08-fold increase in bacteriocin production was obtained with sucrose-containing MRS medium compared to production in standard MRS medium.

• Korean Journal of Microbiology
• /
• v.45 no.4
• /
• pp.339-345
• /
• 2009

Two lactic acid bacteria (LAB) with high ornithine-producing capacity were isolated from kimchi. Examination of the biochemical features using an API kit indicated that the strains belonged to the members of Weissella genus. They were gram positive, short rod-type bacteria, and able to grow anaerobically with $CO_2$ production. The isolates grew well on MRS broth at $25\sim37^{\circ}C$ and pH of 6.0~7.0. The optimum temperature and pH for growth are $30^{\circ}C$ and pH 6.5. The isolates fermented arabinose, ribose, xylose, glucose but not cellobiose, galactose, raffinose, or trehalsoe. The 16S rDNA sequences of isolates showed 99.6% and 99.7% homology with the Weissella koreensis S5623 16S rDNA (access no. AY035891). They were accordingly identified and named as Weissella koreensis OK1-4 and Weissella koreensis OK1-6, and could produce ornithine from MRS broth supplemented with 1% of arginine at a productivity of 27.01 and 31.41 mg/L/h, respectively. This is the first report on the production of ornithine by the genus Weissella isolated from kimchi.

• Microbiology and Biotechnology Letters
• /
• v.44 no.1
• /
• pp.26-33
• /
• 2016

Dominant lactic acid bacteria (LAB) strains were isolated from traditional fermented foods to obtain rare ${\gamma}$-aminobutyric acid (GABA)-producing LAB. Out of 147 isolates, 23 strains that could produce GABA with 1% (w/v) L-monosodium glutamate (MSG) were first isolated. After further screening of these rare GABA-producing LAB by analysis of the glutamate decarboxylase and 16S rRNA gene sequences, Enterococcus faecium JK29 was isolated, and 1.56 mM of GABA was produced after 48 h cultivation in basic de Man, Rogosa, and Sharpe (MRS) medium. To enhance GABA production by E. faecium JK29, the culture conditions were optimized. When E. faecium JK29 was cultivated in optimized MRS medium containing 0.5% (w/v) sucrose and 2% (w/v) yeast extract with 0.5% (w/v) MSG, GABA production reached 14.86 mM after 48 h cultivation at initial conditions of pH 7.5 and $30^{\circ}C$.

• Journal of the Korean Magnetic Resonance Society
• /
• v.10 no.1
• /
• pp.105-114
• /
• 2006

Purpose: We achieved high resolution MR imaging and spectra of human skin in vitro with using a 14.1 T MRI/MRS system, and evaluated the hydration effect of various cosmetic products by measuring the skin's. moisture concentration. Materials and Methods: We used the Bruker 14.1 T MRI/MRS system with a vertical standard bore that was equipped with a DMX spectrometer gradient system (200 G/cm at a maximum 40 A), RF resonators (2, 5 and 10 mm) and Para Vision software. Spin echo and fast spin echo pulse sequences were employed for obtaining the high resolution MR images. The 3D-localized point resolved spectroscopy (PRESS) method was used to acquire the MR spectra. Results: The high resolution MR images and spectra of human skin in vitro were successfully obtained on a 14.1 T system. The water concentration of human skin after applying a moisturizer was higher than that before applying a moisturizer. Conclusions: The present study demonstrated that the high-resolution MR images and spectra of human skin from a high field NMR instrument could be applicable to evaluating the hydration state of the stratum corneum.

• Investigative Magnetic Resonance Imaging
• /
• v.17 no.4
• /
• pp.326-333
• /
• 2013

On $H^1$ MRS (magnetic resonance spectroscopy), malignant tumors show higher concentration of metabolite than benign lesions. Lactate double peak was detected in malignant tumor and endometriosis, and more prominent high concentration was demonstrated in endometriosis. Tuboovarian abscesses and salpingitis do not show prominent peak. Dermoid cysts show high levels of lipid peak. Paratubal cyst and follicular cyst can be showed the lipid peak, however, the concentration of lipid is lower than that of dermoid cyst. $H^1$ MRS of ovarian cystic lesions can give valuable information about the presence of metabolites of ovarian cystic lesions.

• Journal of Mushroom
• /
• v.13 no.1
• /
• pp.50-55
• /
• 2015

Glucan has been shown to have a significant role in the activation of the immune system, including increased activity of macrophages and so on. Sparassis latifolia (formerly S. crispa) is an edible mushroom abundant in dietary fiber and widely known to contain high levels of ${\beta}$-glucan. In the present study, fermentation broths containing soluble ${\beta}$-glucan were prepared by fermentation with mushrooms with four Lactobacillus species (L. plantarum subsp. Plantarum, L. acidophilus, L. helveticus, and L. delbrueckii subsp. Bulgaricus). After culturing four Lactobacillus spp. in MRS broth, each Lactobacillus was inoculated into MRS broth containing S. latifolia powder 5% (w/v) at $37^{\circ}C$ in an anaerobic incubator for five days. It showed that the ${\beta}$-glucan contents were different in each fermentation sample. The suitable conditions for the preparation of mushroom fermentation broths were investigated and discussed.