• The Bulletin of The Korean Astronomical Society
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• v.46 no.2
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• pp.48.3-49
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• 2021

We study the process of panspermia in Milky Way-like galaxies by modeling the probability of successful travel of organic compounds between stars harboring potentially habitable planets. To this end, we apply the modified habitability recipe of Gobat & Hong (2016) to a model galaxy from the MUGS suite of zoom-in cosmological simulations. We find that, unlike habitability, which only occupies narrow dynamic range over the entire galaxy, the panspermia probability can vary be orders of magnitude between the inner (R, b = 1~4 kpc) and outer disk. However, only a small fraction of star particles have very large values of panspermia probability and, consequently, the fraction of star particles where the panspermia process is more effective than prebiotic evolution is much lower than from naïve expectations based on the ratio between panspermia probability and natural habitability. The lunar surface progressively darkens and reddens as a result of sputtering from solar wind particles and bombardment of micrometeoroids. The extent of exposure to these space weathering agents is frequently calculated as the location in a diagram of reflectance at 750 nm

• Food Science and Preservation
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• v.24 no.7
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• pp.975-982
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• 2017

Health of human intestine has deteriorated due to excessive stress and western diet. In this study, Vigna angularis was fermented by Bacillus subtilis KCCM11965P in order to develop prebiotic resource for improving bowel movement. The contents of ash and crude protein were $3.35{\pm}0.04%$ and $21.1{\pm}0.19%$ respectively. Vigna angularis extract (1, 3, 5%) were incubated with 3% (v/v) Bacillus subtilis KCCM 11965P for 0, 24, 48, and 72 h. Total bacterial numbers showed that the combination of 3% powdered seeds and 72 h incubation time was optimum condition for this experiment. Total polyphenol content increased from $0.18{\pm}0.010mg/mL$ in pre-incubation to $0.23{\pm}0.007mg/mL$ in post-incubation with the condition mentioned above. DPPH radical scavenging activity also increased from $36.1{\pm}6.0%$ to $63.6{\pm}5.2%$. Analysis of protease activity showed $2.69{\pm}0.003unit/mL$ in combination of 5% powdered seeds and 72 h incubation time. Amylase activity increased from $1.0{\pm}0.1unit/mL$ in pre-incubation to $26.0{\pm}0.2unit/mL$ in post-incubation. The analysis of free amino acids after incubation with Bacillus subtilis KCCM 11965P showed that leucine increased from 5.22 mg/L to 67.59 mg/L and tyrosine, one of non-essential amino acid also increased 10.08 mg/L to 259.35 mg/L by incubation with 5% powdered seeds. Most of organic acid were reduced by incubation for 72 h. These results suggest that Vigna angularis could be utilized most as a prebiotic resources.

• Korean Journal of Microbiology
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• v.51 no.3
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• pp.288-299
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• 2015

Lactobacillus brevis BK11 obtained from Baikkimchi was selected to study the effects of culture medium, initial pH, atmosphere composition, incubation temperature and time, and prebiotics on growth and production of antimicrobial substances. Growth and antimicrobial substances production of L. brevis BK11 were significantly higher in MRS broth than in BHI or M17 broth. The production of cell mass, lactic acid, and bacteriocin by BK11 strain was at maximum in MRS broth adjusted to pH 6.0. Aerobic and microaerobic conditions were favored cell growth and antimicrobial substances production than anaerobic condition. Biomass and lactic acid production and antimicrobial substances activity of BK 11 were significantly better at 30 and $37^{\circ}C$ than at $25^{\circ}C$. Growth of the strain BK11 entered the stationary growth stage at 24 h after inoculation, and decreased after 36 h. Antimicrobial activities of cell-free culture supernatant and bacteriocin solution were highest when cultured in MRS broth with an initial pH 6.0 for 24-30 h at $37^{\circ}C$. In addition, the highest cell number and lactic acid and bacteriocin production were recorded in the presence of 1 and 2% (w/v) fructooligosaccharide (FOS), however, inulin and raffinose did not affect biological and physicochemical characteristics and antimicrobial activities of L. brevis BK11 cultures. According to these results, production of antimicrobial substances by L. brevis KB11 was closely associated with cell density. Under optimal conditions for antimicrobial substances production, L. brevis BK11 effectively inhibited the growth of Helicobacter pylori ATCC 43504.

• Journal of Life Science
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• v.28 no.1
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• pp.68-77
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• 2018

The purpose of this study was to isolate the probiotic lactic acid bacteria, and verify the possibility of the final selection strain as probiotic material. For screening of biogenic amines non-producing microorganisms, 42 lactic acid bacteria were isolated from various berries, extract and vinegar grown in Sunchang. Isolates were investigated for various physiological activities such as extracellular enzyme, antimicrobial and antioxidant activities, and 5 isolates were firstly screened. SBB07 was finally selected by analyzing the biogenic amine, and named Lactobacillus brevis SBB07 by 16S rRNA sequencing analysis. Next, SBB07 was assayed for their survival ability when exposed to acidic and bile conditions as well as heat and antibiotic resistance. As a result, SBB07 showed more than 86% and 54% higher survival rate in acidic condition at pH 2.0 and bile resistance with 0.5% oxgall. In addition, SBB07 showed a survival rate of more than 113% in $60^{\circ}C$, and also confirmed that it has resistant to various antibiotics. As a result of confirming the possibility of prebiotics, SBB07 showed the best utilization of GOS as a prebiotic substrate, and utilization of FOS and inulin were also high. These results suggest that SBB07 have good potential for application as probiotic lactic acid bacteria.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.5
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• pp.749-755
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• 2014

Exopolysaccharides (EPSs) have been widely used in the food industry as viscofying, stabilizing, and emulsifying agents as well as in the pharmaceutical industry for their immunomodulatory, anti-tumor, and anti-inflammatory effects. A total of 458 lactic acid bacteria (LAB) strains isolated from several kinds of soybean pastes were screened for the production of homo-EPS (HoPS). LAB isolates were primarily screened using thin layer chromatography (TLC) and further screened polymerase chain reaction (PCR) targeting genes involved in HoPS production. Six LAB isolates producing high amounts of HoPS were identified by TLC. Among these isolates, glucansucrase gene was amplified in two strains (JSA57, JSB22), whereas the fructansucrase gene was detected in three strains (JSA57, JSB22, JSB66). After isolating the strains, their morphological characteristics and 16S rDNA sequences were determined. Six species were identified as L. alimentarius HSB15, L. plantarum JSA22, L. pentosus JSA57, L. brevis JSB22, L. alimentarius JSB66, and L. parabrevis JSB89. To evaluate the potential probiotic properties of these LAB, their survival rates against a simulated intestinal environment were determined. After 2 hr of incubation in artificial gastric juice, survival rates of JSA57, JSB90, JSB22, and JSB66 were all greater than 50%. After 2 hr of incubation in bile juice, viable cell count of JSB22 was similar with initial vial cell counts. Growth of the six LAB was screened in arabino-oligosaccharide (AOS)-containing MRS broth. Results showed that growth of the isolates selectively increased after culture in AOS-containing media. Strain JSB22 (6 hr), JSB66 (6 hr), HSB15 (20 hr), and JSA22 (29 hr) showed maximum growth rate. Especially, JSB22 showed the highest growth rate. These results suggest that EPS-producing LAB isolated from Deonjang could be applied as synbiotics.

• Journal of Life Science
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• v.23 no.10
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• pp.1295-1303
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• 2013

According to facts revealed up until the present, there are a total of 68 known phyla on earth, including 55 phyla of bacteria and 13 phyla of archaea. The human large intestine has 9 phyla of microorganisms, which is a relatively lower diversity compared to the general environments of soil or sea. The diversity of intestinal microorganisms is affected by the characteristics of the host (genetic background, sex, age, immune system, and gut motility), the diet (non-digestible carbohydrates, fat, prebiotics, probiotics), and the intake of antibiotics, which in turn have an effect on energy storage processes, gene expressions, and even metabolic diseases like obesity. Probiotics are referred to as living microorganisms that improve the intestinal microbiota and contribute to the health of the host; in addition, probiotics usually comprise lactic acid bacteria. Recently, bacteriotherapy using probiotics has been utilized to treat sicknesses like diarrhea and irritable bowel syndrome. Prebiotics are a food ingredient which can selectively adjust intestinal microorganisms and which comprise inulin, fructooligosaccharides, galactooligosaccharides, and lactulose. In recent days, attention has been paid to the use of dietary cellulose in the large intestine and the production of short chain fatty acids (short-chain fatty acids) in relation to obesity and anticancer. More research into microorganisms in the large intestine is necessary to identify specific microorganism species, which are adjusted by diverse non-digestible carbohydrates, prebiotics, and probiotics in the large intestine and to understand the connection between sicknesses and metabolites like short chain fatty acids produced by these microorganism species.

• Food Science and Biotechnology
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• v.17 no.3
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• pp.514-518
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• 2008

After overproduction of a recombinant $\beta$-galactosidase of Bifidobacterium infantis in Pichia pastoris, a synthesis of galacto-oligosaccharides (GOS) from 36% lactose using the enzyme (170.74 U/mg) was investigated. The transgalactosylation ratio reached up to 25.2% with 83.1% conversion of initial lactose and the maximum yield of GOS was 40.6%. The GOS syrup was composed of a 13.43% galacto-oligosaccharides, 5.06% lactose, and 8.76% monosaccharides. The prebiotic effect of GOS on the growth of bifidobacteria and lactobacilli strains was investigated in vitro. The maximum growth rate of Bifidobacterium breve and Lactobacillus acidophillus in GOS syrup (5%, v/v) media were 0.49 and 0.96/hr that are higher than those in 1%(w/v) galactose and 1%(w/v) lactose containing media. However, there was no significant difference between the specific growth rates of L. acidophillus in 1%(w/v) glucose and 5%(v/v) GOS syrup. Our data showed that GOS definitely promoted the growth of B. breve ATCC $15700^T$ and L. acidophilus ATCC 33323.

• Journal of Microbiology and Biotechnology
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• v.26 no.7
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• pp.1267-1277
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• 2016

Currently, enzymatic synthesis of lactulose, a synthetic prebiotic disaccharide, is commonly performed with glycosyl hydrolases. In this work, a new type of lactulose-producing biocatalyst was developed by displaying β-galactosidase from Bacillus stearothermophilus IAM11001 (Bs-β-Gal) on the surface of Bacillus subtilis 168 spores. Localization of β-Gal on the spore surface as a fusion to CotX was verified by western blot analysis, immunofluorescence microscopy, and flow cytometry. The optimum pH and temperature for the resulting spore-displayed β-Gal was 6.0 and 75℃, respectively. Under optimal conditions, it showed maximum activity of 0.42 U/mg spores (dry weight). Moreover, the spore-displayed CotX-β-Gal was employed as a whole cell biocatalyst to produce lactulose, yielding 8.8 g/l from 200 g/l lactose and 100 g/l fructose. Reusability tests showed that the spore-displayed CotX-β-Gal retained around 30.3% of its initial activity after eight successive conversion cycles. These results suggest that the CotX-mediated spore-displayed β-Gal may provide a promising strategy for lactulose production.

• The Korean Journal of Food And Nutrition
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• v.25 no.2
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• pp.284-290
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• 2012

물(water, TW), 에탄올(ethanol, TE) 및 핵산(n-hexane, TH)을 이용하여 탱자씨 추출물(trifoliate orange seed extracts, TSEs)을 각각 제조한 후 그람양성 식중독균 6종(Bacillus cereus KCCM 11341, Bacillus subtilis KCTC 1022, Listeria monocytogenes ATCC 12692, Staphylococcus aureus ATCC 19111, Streptococcus mutans KCTC 3065 및 Yersinia enterocolitica KCCM 41657)에 대한 항균활성과 Lactobacillus acidophilus IFO 3025에 대한 프레바이오틱 효과(prebiotic effect)를 측정하였다. 그 결과, 탱자씨 핵산추출물(TH)은 S. aureus ATCC 19111에 대해 배양시간이 증가함에 따라 대조군에 비해 강한 증식저해활성을 보였으며, 탱자씨 에탄올 추출물(TE)은 약간의 증식저해활성을 보였다. 특히, 배양 81시간 후 대조군은 90.31%의 증식활성을 보인 것에 반해 탱자씨 핵산추출물과 에탄올추출물은 64.95%와 75.50%의 증식활성을 각각 보였다. 탱자씨 추출물의 Lb. acidophilus IFO 3025에 대한 프레바이오틱 효과는 대조군에 비해 증식활성을 보이지는 않았으나, 적어도 생육저해효과를 보이지는 않았다. 따라서 탱자씨의 핵산 및 에탄올 추출물은 S. aureus ATCC 19111에 대한 항균활성물질로서의 가능성을 제시하였다.

• Korean Journal of Agricultural Science
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• v.47 no.3
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• pp.445-457
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• 2020

Prebiotics are defined as "Nondigestible food ingredients that beneficially affect the host by selectively stimulating the growth and activity of bacteria in the intestine" and as defined improve host health. This study was carried out to investigate the effects of bifidobacteria (Bifidobacterium lactis BB12 and Bifidobacterium longum BB536) growth enhancer (BE0623) supplement as a prebiotic. The addition of BE0623, a growth promoting material for bifidobacteria, significantly increased bifidobacteria viable cells counts in fermented milk by about 45 to 75 times compared to the non-added control group. In addition, microscopic observation showed a significant effect on proliferation of bifidobacteria in fermented milk with added BE0623. The viable cell counts in bifidobacteria also increased roughly 102-fold compared to the control group (non-added BE0623) and was higher than that of commercial growth promoters. Each fraction obtained though the purification of BE0623 influenced the increase of bifidobacteria growth. Culturing bifidobacteria with a combination of fractions of BE0623 had a synergistic effect compared to culturing bifidobacteria with each fraction individually. When any of the fractions were not added, the effect of the growth enhancer on bifidobacteria was reduced. These results indicate that all fractions contain substances that promote the growth of bifidobacteria. Therefore, BE0623 is considered to be available as a growth promoting material for bifidobacterium.