• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.20 no.8
• /
• pp.33-41
• /
• 2021

Recently, many studies have been conducted on substituting fossil fuels with bio-refineries in existing industrial systems using biomass. Among the various bio-refineries, microalgae have received wide attention because it uses inorganic compounds to produce useful substances, which are extracted by a cell disruption process. Although numerous cell disruption methods exist, cell disruption efficiency has been studied by ultrasonic treatment. Ultrasound is a high-frequency (20 kHz or higher) sound wave and causes cell disruption by cavitation when passing through a solvent. In this study, we used the microalgal species Chlorella sp., which was cultured in a plate-type photobioreactor. The experiment was conducted using a continuous low-frequency processing device. The reduction of cells with time due to cell disruption was fitted using a logistic model, and optimum conditions for highly efficient cell disruption were determined by conducting experiments under multiple conditions.

• Microbiology and Biotechnology Letters
• /
• v.50 no.3
• /
• pp.395-403
• /
• 2022

In this study, we identified that the fermentation of Korean indigenous probiotics and red ginseng produced ginsenoside compound K (CK) from major ginsenosides. Based on whole genome sequencing of 19 probiotics species, β-glucosidase, α-arabinofuranosidase, β-xylosidase, and α-rhamnosidase related to bioconversion of ginsenosides are identified in the genome of 19 species, 3 species, 6 species, and 8 species, respectively. Among the 19 probiotics species, Bifidobacterium longum CBT BG7 converted from ginsenoside Rb1 to CK, and both B. breve CBT BR3 and B. lactis CBT BL3 converted ginsenoside Rb1 to Rd. The final concentration and yield of ginsenoside F2 and CK were higher in the fermentation with the nondisrupted cells than with disrupted cells. The combination of both CBT BG7 and BL3, and CBT BG7 and BR3 showed higher amounts of F2 than CBT BG7 only. CBT BG7 with adding α-amylase increased the amounts of F2. In this study, we identified that the fermentation of both Korean indigenous probiotic bacteria CBT BG7, BR3 and BL3, and red gingseng is able to produce CK, a bioactive compound that promotes health benefits.

• Biomedical Science Letters
• /
• v.2 no.2
• /
• pp.175-185
• /
• 1996

The mitogen-activated protein(MAP) kinase signal transduction pathway represents an important mechanism by which mitogen, such as serum and PMA, regulate cell proliferation and differentiation. Target substrates of the MAP kinase are located within several compartments containing plasma membranes and nucleus. We now report that serum addition induces proliferation of the P388 murine leukemia cell, but PMA does not, while both serum and PMA treatment cause translocation of the MAP kinase, mainly p42$^{mapk}$ isoform, from cytosol into the nucleus, which was monitored by immunoblot analysis using polyclonal anti-ERK1 antibodies. We investigated whether the MAP kinase was capable of phosphorylating c-Jun protein and GST-fusion proteins, the P562$^{kk}$N-terminal peptides (1-77 or 1-123 domain) of the T cell tyrosine kinase, using the partially purified MAP kinase by SP-sephadex C-50, phenyl superose and Mono Q column chromatography. We found that the partially purified MAP kinase was able to phosphorylate c-Jun protein and the GST-fusion protein expressed using E.coli DH5$\alpha$ which is transformed with pGEX-3Xb plasmid vector carrying of p562$^{kk}$N-terminal peptide-encoding DNA. These results imply that tyrosine kinase receptor/Ras/Raf/MAP kinase pathway is a major mechanism for mitogen-induced cell proliferation in P388 murine leukemia cell and that the various MAP kinase isoforms may have their own target substrates located in distinct subcellular compartments.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2013.10a
• /
• pp.943-945
• /
• 2013

The study of Schwann cell myelination has been facilitated by the availability to isolate and establish pure population of primary Schwann cells. Dorsal root ganglia (DRG) of mouse embryo as source of Schwann cells were used in this study. This method includes three steps: first step of dissociation of the embryonic DRG, second step of expansion of Schwann cell precursors, followed by mechanical separation of the Schwann cell-neuronal network from the underlying fibroblasts, and third step of purification of Schwann cells from the associated neurons and subsequent expansion of the purified Schwann cells. We made a highly purified population of Schwann cells and Schwann cell-neuron networks in a short period using this procedure.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.49 no.3
• /
• pp.285-290
• /
• 2023

In this study, the anti-inflammation efficacy of Lactobacillus johnsonii derived from Kimchi was investigated. Raw 264.7 cells, which are rat-derived macrophages, were treated with Lactobacillus johnsonii lysate to confirm the expression level of TNFα and IL1β, which are inflammatory markers, and when treating 250 ㎍/mL extract, the expression level of TNFα and IL1β decreased by 40.55% and 34.66% compared to the control group treated with 1 ㎍/mL LP, respectively. In addition, as a result of confirming the transcriptional activity of NF-κB, a key transcription factor in cytokine expression by LPS, it was confirmed that the transcriptional activity of NF-κB was 40.76% inhibited compared to the control group treated with 1 ㎍/mL LPS. Therefore, the results of this study confirmed that Lactobacillus johnsonii lysate is likely to be an anti-inflammatory or skin-soothing functional material by preventing the expression of cytokine by LPS and controlling NF-κB transcriptional activity.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.20 no.10
• /
• pp.63-71
• /
• 2021

Using fossil fuels in existing industrial systems causes a variety of social problems. Recently, many studies have been conducted on bio-refineries, which aim to actively utilize biomass to reduce the use of fossil fuels and solve various social problems. Among them, research using microalgae as a third-generation biomass has attracted considerable attention. Microalgae use inorganic matter to produce organic matter, and cell destruction is necessary to extract useful organic materials from microalgae. The extracted organic materials are currently used in various industrial fields. Numerous cell-destruction methods exist. We have investigated cell disruption by sonication, especially its efficiency. Ultrasound is a sound wave with frequencies above 20 kHz, and destroys cells by sending high energy through a cavitation that occurs, according to the characteristics of the sound wave. The Dunaliella salina microalgae used in this study was cultured in a flat-type photobioreactor. Experiments were performed using a batch low-frequency processing device. Logistic model was applied to analyze the results of cell-destruction experiments using ultrasound. The proper conditions for the most efficient cell destruction were OD 1.4(microalgae concentration)), 54watt(output power) and 200mL(microalgae capacity).

• Journal of Life Science
• /
• v.7 no.2
• /
• pp.79-87
• /
• 1997

To determine the cause of Vibrio septicemia by understanding the characteristics endotoxin from Vibrio vulnificus, lethal dose, heat resistance and vascular permeability enhancing activity were svaluated using vegestative cell and cell homogenate and the result is as follows: 1. Vibrio vulnificus CDC B3547 of patient origin did not exihibit any significant difference in toxicity compared to Vibrio vulnificus B57 of enviroment origin. 2. Strong toxicity was observed when viable cell count of Vibrio vulnificus CDC B3547 was more than 10$^{7}$/ml. 3. Toxicity of cell homogenate was completely inactivited upon geating at 80$^{\circ}$C for 20min. 4. Cell homogenate did not show hemolyic activity but was acknowleged to have cytotoxicity. 5. Major lethal toxin against mouse was existed in Vibrio vulnificus CDC B3547; however, separation of LPS and LPS-protein complex was not successful using the current technique.

• Membrane Journal
• /
• v.33 no.6
• /
• pp.390-397
• /
• 2023

Conventional extraction methods for polyhydroxybutyrate (PHB), a sustainable alternative to petroleum-based plastics, cause a decrease in molecular weight and a change in properties. In this work, we developed a method to extract PHB accumulated in microorganisms by physical disruption through filtration using a spiked carbon nanotube (CNT) membrane with functionalized CNT. In addition, filtration of the PHB-containing microbial solution was performed to confirm PHB extraction, which was found to be 4% more efficient than chloroform, the most used extraction method. These results indicate that the spiked CNT membrane has potential in the bioplastics recovery process.

• Journal of Life Science
• /
• v.19 no.2
• /
• pp.179-184
• /
• 2009

Zinc is an essential trace element for human and plays an important biological role in antioxidant properties. We have been reported that zinc-enriched S. cerevisiae FF-10 contained 392 mg% in the YM basal and 3,193 mg% in the YM optimal medium. Antioxidative activity of FF-10 was tested in vitro models by DPPH (${\alpha},{\alpha}'$-diphenyl-${\beta}$-picrylhydrazyl) radical scavenging activity and lipid peroxidation using linoleic acid (LA) and rat liver homogenate. DPPH radical scavenging activity was higher in the cell-free extract of FF-10 cultured in the YM optimal medium (YMOM) than that in the YM basal medium (YMBM). The inhibition activity of lipid peroxidation using rat liver homogenate was shown in the following order: BHT > YMOM > YMBM and these values were dose dependently. The lipid peroxidation of the control mixture by ferric thiocyanate and TBA methods using LA was increased rapidly as typical peroxidation curve of LA from one day and the antioxidation activity of the cell free extracts by cultivating FF-10 in the YMOM were higher than that of the YMBM. Result of this study indicate that the cell-free extracts containing a high intercellular zinc of S. cerevisiae FF-10 cultured in YMOM showed strong antioxidation capacities in DPPH radical scavenging activity and lipid peroxidation using LA and rat liver homogenate.

• 한국생물공학회:학술대회논문집
• /
• 2005.10a
• /
• pp.889-893
• /
• 2005

Cell lysis method is very important to study intracellular metabolites in microorganisms. In this study, various cell lysis methods were compared to find a good method analysing intracellular metabolites in P. pastoris. P. pastoris was cultivated in YPD medium at 30 $^{\circ}C$, 200 rpm for 24 hours and its morphology as well as the change in strain's shape were observed by microscopy. The UV/vis spectrophotometer was used to measure intracellular protein concentrations.