• Korean Journal of Organic Agriculture
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• v.24 no.3
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• pp.497-510
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• 2016

This study was carried out to get basic resources for the industrial use of Lactobacillus bulgaricus SP5. The antibacterial activity of the supernatant obtained from Lactobacillus bulgaricus SP5 was tested against the pathogenic bacteria such as Escherichia coli KCCM 11234, Salmonella enteritidis KCCM 3313, Salmonella enteritidis KCCM 12021, and Salmonella typhimurium KCCM 40253. The supernatant of L. bulgaricus SP5 showed antibacterial activity against tested pathogenic bacteria. The antibacterial activity was examined after adjusting pH and heat treatment of supernatant. Heat treatment of supernatant had antibacterial activity against pathogenic bacteria at all temperature. However, pH changes showed no antibacterial activity. Antibacterial activity of the supernatant was confirmed to be due to organic acids (lactic, acetic, phosphoric, succinic, pyroglutamic, citric, malic, and formic acid).

• Journal of Microbiology and Biotechnology
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• v.26 no.10
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• pp.1736-1745
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• 2016

The interactions of microbiota in the gut play an important role in promoting or maintaining the health of hosts. In this study, in order to investigate and compare the effects of dietary supplementation with Lactobacillus pentosus HC-2 (HC-2), Enterococcus faecium NRW-2, or the bacteria-free supernatant of a HC-2 culture on the bacterial composition of Litopenaeus vannamei, Illumina sequencing of the V1-V2 region of the 16S rRNA gene was used. The results showed that unique species exclusively existed in specific dietary groups, and the abundance of Actinobacteria was significantly increased in the intestinal bacterial community of shrimp fed with the bacteria-free supernatant of an HC-2 culture compared with the control. In addition, the histology of intestines of the shrimp from the four dietary groups was also described, but no obvious improvements in the intestinal histology were observed. The findings in this work will help to promote the understanding of the roles of intestinal bacteria in shrimps when fed with probiotics or probiotic supernatant.

• Applied Biological Chemistry
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• v.17 no.2
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• pp.138-142
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• 1974

Biosynthesis of glycolipid from glucosamine and $C_{13:0}$ fatty acid was attempted using an enzyme preparation which was extracted from Selenomonas ruminantium grown in lactic acid medium by means of ultrasonication, and with cofactors of ATP, Co A, $Mg^{++}$, and UTP. The results are summarized as follows: 1. The rate of synthesis of glycolipid from $^{14}C-glucosamine$ and tridecyl CoA by an enzyme from Selenomonas ruminantium was promoted by the presence of co-factors, ATP, Mg, and UTP. 2. The rate of incorporation of $^{14}C-glucosamine$ into glycolipid by the centrifugal fraction of bacterial preparation was the highest in the 105,000 g supernatant fraction, indicating about twice the enzyme activity as the 6,000 rpm supernatant fraction. 3. The biosynthesis of glycolipid from $^{14}C-glucosamine$ and tridecyl-CoA by the crude enzyme of the 105,000 g supernatant fraction of Selenomonas ruminantium cell preparation proceeded the most part of it in 30 minutes and completed in an hour.

• Food Science of Animal Resources
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• v.33 no.4
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• pp.501-507
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• 2013

Lysozyme was trapped from $2{\times}$ diluted egg white using Amberlite FPC 3500 ion exchange resin (1 g/10mL of egg white). The lysozyme bound to the resin was recovered using 0.1 N glycine-NaOH buffers, pH 9.0, containing 0.5 M NaCl. After separating lysozyme, the pH of the egg white solution was adjusted to 4.75 and centrifuged to remove interfering proteins. The supernatant was collected, added with 2.5% citric acid and 5.0% ammonium sulfate combination to precipitate egg white proteins, except for ovalbumin. After centrifugation, both supernatant (S1) and precipitant were collected. The precipitant was dissolved with 4 volumes of distilled water, and then 2.0% ammonium sulfate and 1.5% citric acid combinations added, stirred overnight in a cold room, and centrifuged. The resulting supernatant (S2) was pooled with the first supernatant (S1), desalted using an ultrafiltration unit, heat-treated at $70^{\circ}C$ for 15 min, and then centrifuged. The supernatant was collected as an ovalbumin fraction and lyophilized. The separated proteins were confirmed using Western blotting. The yield of lysozyme and ovalbumin was > 88.9% and > 97.7%, respectively, and the purity of lysozyme and ovalbumin was > 97% and 87%, respectively. The results indicated that the protocol was simple, and separated lysozyme and ovalbumin effectively.

• Preventive Nutrition and Food Science
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• v.3 no.4
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• pp.379-381
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• 1998

An angiotensin converting enzyme (ACE) inhibitor was isolated and partially purified from bovine blood plasma. Bovine blood plasma was obtained after removing blood cells by centrifugation, followed by the addition of anticoagulant to whole bovine blood. To precipitate plasma proteins, bovine blood plasma was treated with 4% trichloroacetic acid (TCA) as a final concentration .An ACE inhibitor was isolated from TCA supernatnat, using ultrafiltration, gel permeation chormatography, and reverse-phase high pressure liquid chromatogrpahy. The ACE inhibitor purified from TCA supernatant had IC50 values of 9.4$\mu$M.

• 연구논문집
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• s.30
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• pp.67-77
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• 2000

This study was performed to investigate the characteristics and performance of model Decanter for separating swine wastewater to solid and liquid which is slurry state with 12.6% TS. Swine wastewater of the slurry tank was pumped into model Decanter which capacity was $2m^3$/hr in 10% TS Slurry inside of bowl was separated to solid-liquid by centrifugal acceleration. Sampling was done in the section of slurry feed pipe, supernatant outflow pipe, cake discharge pipe. After solid-liquid separation TS, $COD_cr$ and slurry volume reduction effect represented 38%, 40%, 19.6% respectively. Relation factor of model Decanter operation slurry concentration, optimum retention time of slurry, overflow velocity of supernatant, supernatant concentration, sludge removal rate etc. Optimal operation conditions can be set and evaluated efficiency based on the experimental results in the case of Decanter adopted for solid-liquid separation in highly concentrated swine wastewater.

• Restorative Dentistry and Endodontics
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• v.22 no.2
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• pp.761-768
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• 1997

Microorganisms and their by-products are considered to be the major causes of pulpal and periapical pathosis. The role of microorganisms in endodotic infection has been studied regarding the prevalence of particular organisms found in root canal and periapical lesions. The aim of this study was to investigate the effect of culture supernatants of several oral microorganims isolated from infected root canals on the viability of cultured cell lines using colorimetirc assay. S. simulans, S. sciuri, E. faecium, S. intermedius, S. mitis, S. sanguis and S. uberis were incubated in Todd-Hewitt broth for 16 hours. 20 and 100ul of filtered bacterial cell culture supernatants were added to MK and Hep-2 cells. Cell viability was measured using MIT colorimetric assay. 20ul and 100u1 of S. sanguis supernatant showed significant cytotoxicity compared to control on MK cells. 100ul of S. sanguis supernatant significantly depressed viability of HEp-2 cells. E. faecium and S. intermedius did not affect the viability of MK and HEp-2 cells.

• Journal of Microbiology and Biotechnology
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• v.30 no.12
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• pp.1854-1861
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• 2020

Staphylococcus aureus is one of the most common microorganisms and causes foodborne diseases. In particular, biofilm-forming S. aureus is more resistant to antimicrobial agents and sanitizing treatments than planktonic cells. Therefore, this study aimed to investigate the anti-biofilm effects of cell-free supernatant (CFS) of Saccharomyces cerevisiae isolated from cucumber jangajji compared to grapefruit seed extract (GSE). CFS and GSE inhibited and degraded S. aureus biofilms. The adhesion ability, auto-aggregation, and exopolysaccharide production of CFS-treated S. aureus, compared to those of the control, were significantly decreased. Moreover, biofilm-related gene expression was altered upon CFS treatment. Scanning electron microscopy images confirmed that CFS exerted anti-biofilm effects against S. aureus. Therefore, these results suggest that S. cerevisiae CFS has anti-biofilm potential against S. aureus strains.

• Korean Journal of Soil Science and Fertilizer
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• v.7 no.4
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• pp.209-213
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• 1974

The isozymes of glutamic oxalacetic transaminase from young rice root were isolated by DEAE-cellulose column chromatography, and investigated some of their enzymic properties. Obtained results were summarized as follows: 1. 93 percent of GOT activity in rice root existed in supernatant fraction, and their specific activity exibited the same pattern. 2. The rice root contained two types of GOT isozyme; cationic and anionic GOT. It seemed that both of them were distributed in supernatant fraction. 3. GOT isozymes of rice root on the pH dependance showed their maximum activity at 7.4. 4. On the stability of GOT isozymes for temperature, anionic GOT was more unstable than cationic GOT. 5. Apparent Michaelis constant for L-aspartate of GOT isozymes from rice root showed 12-14mM in the cationic GOT and 16mM in the anionic GOT, respectively.

• Journal of the Korean Wood Science and Technology
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• v.44 no.3
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• pp.398-405
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• 2016

The cellulose nanofibers (CNFs) were prepared by wet disk-milling (WDM) and fractionated by settling method into supernatant, middle and sediment fractions. The diameter and its distribution of the fractionated CNFs were investigated. With increasing WDM passing number, precipitation became delayed. Weight fraction at sediment fraction was decreased, whereas those at supernatant and middle fractions were increased with increasing WDM passing number. Diameter distribution of CNFs at supernatant fraction was narrowest and became broaden at middle and sediment fraction. Filtration time was longer in order of supernatant, middle and sediment fraction.