• Journal of Microbiology and Biotechnology
• /
• v.30 no.3
• /
• pp.382-390
• /
• 2020

Periplanetasin-4 is an antimicrobial peptide with 13 amino acids identified in cockroaches. It has been reported to induce fungal cell death by apoptosis and membrane-targeted action. Analogs were designed by substituting arginine residues to modify the electrostatic and hydrophobic interactions accordingly and explore the effect of periplanetasin-4 through the increase of net charge and the decrease of hydrophobicity. The analogs showed lower activity than periplanetasin-4 against gram-positive and gram-negative bacteria. Similar to periplanetasin-4, the analogs exhibited slight hemolytic activity against human erythrocytes. Membrane studies, including determination of changes in membrane potential and permeability, and fluidity assays, revealed that the analogs disrupt less membrane integrity compared to periplanetasin-4. Likewise, when the analogs were treated to the artificial membrane model, the passage of molecules bigger than FD4 was difficult. In conclusion, arginine substitution could not maintain the membrane disruption ability of periplanetasin-4. The results indicated that the attenuation of hydrophobic interactions with the plasma membrane caused a reduction in the accumulation of the analogs on the membrane before the formation of electrostatic interactions. Our findings will assist in the further development of antimicrobial peptides for clinical use.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.24 no.1
• /
• pp.139-147
• /
• 1997

Argon laser used in this case report, is special in having two wavelength of 488, 514nm blue-green visible light spectrum. Blue light is used for composite resin polymerization and caries detection. Green light is used for soft tissue surgery and coagulation. Maximum absorption of this laser light occurs in red pigmentation such as hemoglobin. The argon laser may be well-suited for selective destruction of blood clots and hemangioma with minimal damage to adjacent tissues. Argon laser light penetrates tissue to the 1 mm depth, so its thermal intensity is lower than $CO_2$ laser light. Also, due to its short wavelength it can be focused in a small spot and even single gene can be excised by this laser and microscopy. After applicating argon laser to 4 patient for surgical procedure and to 1 patient for curing the composite resin, following results were obtained. 1. Improved visibility were gained due to hemostasis and no specific technique were needed according to easy recontouring of the tissue. 2. Ability to use by contact mode, tactile sense was superior but tissue dragability and accumulation of tissue on the tip needed sweeping motion. 3. Additive local anesthetic procedure was needed. 4. No suture and less curing time reduced chair time, this made argon laser available in pediatric dentistry.

• Journal of Mushroom
• /
• v.15 no.2
• /
• pp.61-68
• /
• 2017

This study focused on evaluating the phytoextraction of heavy metals (Co, Pb, and Zn) induced by bioaugmentation of button mushroom compost (BMC) in Helianthus annuus (sunflower). When the potential ability of BMC to solubilize heavy metals was assessed in a batch experiment, the inoculation with BMC could increase more the concentrations of water-soluble Co, Pb, and Cd by 35, 25, and 45% respectively, compared to those of non-inoculated soils. BMC-assisted growth promotion and metal uptake in H. annuus was also evaluated in a pot experiment. In comparison with non-inoculated seedlings, the inoculation led to an increase in the growth of H. annuus by 27, 25, and 28% in Co-, Pb-, and Zn-contaminated soils, respectively. Moreover, enhanced accumulation of Co, Pb, and Zn in the shoot and root systems was observed in inoculated plants, where metal the translocation from root to the above-ground tissues was also found to be enhanced by the BMC. Evidently, these results suggest that the BMC could be effectively employed in enhancing the phytoextraction of Co, Pb, and Zn from contaminated soils.

• The Korean Journal of Food And Nutrition
• /
• v.30 no.6
• /
• pp.1292-1298
• /
• 2017

The purpose of this study was to evaluate the antioxidant and anti-adipogenic activities of Ligularia stenocephala (L. stenocephala) extract. The contents of the total polyphenol of the extract was 55.950 mg GAE/g residue. Antioxidant activities of L. stenocephala were evaluated by free radical scavenging ability and a reducing power test. 2,2'azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and ${\alpha}$-${\alpha}$-diphenyl-${\beta}$-picrylhydrazyl (DPPH) free radical scavenging activities of the extract were approximately 90% and 70%, respectively. Reducing power of the extract was 258.833 mg TE/g residue. The anti-adipogenic activity of L. stenocephala extract was examined in 3T3-L1 cells. During adipocyte differentiation, the 3T3-L1 cells were treated both with and without the extract. L. stenocephala extract suppressed the lipid accumulation in a concentration-dependent manner in the 3T3-L1 cells. The L. stenocephala extract inhibited the expression of peroxisome proliferator activated receptor ${\gamma}$ ($PPAR{\gamma}$) and adipocyte protein 2 (aP2) proteins, compared with control adipocytes. These results indicate that L. stenocephala could be regarded as a potential source natural antioxidant and an anti-obesity agent.

• BMB Reports
• /
• v.38 no.6
• /
• pp.717-724
• /
• 2005

The nontoxic B subunit of cholera toxin (CTB) can significantly increase the ability of proteins to induce immunological tolerance after oral administration, when it was conjugated to various proteins. Recombinant CTB offers great potential for treatment of autoimmune disease. Here we firstly investigated the feasibility of silkworm baculovirus expression vector system for the cost-effective production of CTB under the control of a strong polyhedrin promoter. Higher expression was achieved via introducing the partial non-coding and coding sequences (ATAAAT and ATGCCGAAT) of polyhedrin to the 5' end of the native CTB gene, with the maximal accumulation being approximately 54.4 mg/L of hemolymph. The silkworm bioreactor produced this protein vaccine as the glycoslated pentameric form, which retained the GM1-ganglioside binding affinity and the native antigenicity of CTB. Further studies revealed that mixing with silkworm-derived CTB increases the tolerogenic potential of insulin. In the nonconjugated form, an insulin : CTB ratio of 100 : 1 was optimal for the prominent reduction in pancreatic islet inflammation. The data presented here demonstrate that the silkworm bioreactor is an ideal production and delivery system for an oral protein vaccine designed to develop immunological tolerance against autoimmune diabetes and CTB functions as an effective mucosal adjuvant for oral tolerance induction.

• Journal of Microbiology and Biotechnology
• /
• v.26 no.5
• /
• pp.846-853
• /
• 2016

We displayed four types of Solanum nigrum metallothionein (SMT) for the first time on the surface of Saccharomyces cerevisiae using an α-agglutinin-based display system. The SMT genes were amplified by RT-PCR. The plasmid pYES2 was used to construct the expression vector. Transformed yeast strains were confirmed by PCR amplification and custom sequencing. Surface-expressed metallothioneins were indirectly indicated by the enhanced cadmium sorption capacity. Flame atomic absorption spectrophotometry was used to examine the concentration of Cd²⁺ in this study. The transformed yeast strains showed much higher resistance ability to Cd²⁺ compared with the control. Strikingly, their Cd²⁺ accumulation was almost twice as much as that of the wild-type yeast cells. Furthermore, surface-engineered yeast strains could effectively adsorb ultra-trace cadmium and accumulate Cd²⁺ under a wide range of pH levels, from 3 to 7, without disturbing the Cu²⁺ and Hg²⁺. Four types of surfaceengineered Saccharomyces cerevisiae strains were constructed and they could be used to purify Cd²⁺-contaminated water and adsorb ultra-trace cadmium effectively. The surface-engineered Saccharomyces cerevisiae strains would be useful tools for the bioremediation and biosorption of environmental cadmium contaminants.

• Journal of Microbiology and Biotechnology
• /
• v.29 no.12
• /
• pp.1993-2005
• /
• 2019

Thermophilic anaerobic digestion (TAD) is characterized by higher biogas production rates as a result of assumedly faster microbial metabolic conversion rates compared to mesophilic AD. It was hypothesized that the thermophilic microbiome with its lower diversity than the mesophilic one is more susceptible to disturbances introduced by alterations in the operating factors, as an example, the supply of nitrogen-rich feedstock such as poultry manure (PM). Laboratory scaled TAD experiments using cattle slurry and increasing amounts of PM were carried out to investigate the (in-) stability of the process performance caused by the accumulation of ammonium and ammonia with special emphasis on the microbial community structure and its dynamic variation. The results revealed that the moderate PM addition, i.e., 25% (vol/vol based on volatile substances) PM, resulted in a reorganization of the microbial community structure which was still working sufficiently. With 50% PM application, the microbial community was further stepwise re-organized and was able to compensate for the high cytotoxic ammonia contents only for a short time resulting in consequent process disturbance and final process failure. This study demonstrated the ability of the acclimated thermophilic microbial community to tolerate a certain amount of nitrogen-rich substrate.

• Nutrition Research and Practice
• /
• v.1 no.4
• /
• pp.260-265
• /
• 2007

Preservation methods on the physiological and brewing technical characters in bottom and top brewing yeast strains were investigated. The preserved yeasts were reactivated after 24 months storage and grown up to stationary phase. The samples of filter paper storage indicated a higher cell growth and viability during propagation than those of nitrogen and lyophilization storage independent on propagation temperature. In addition, the filter paper storage demonstrated a faster absorption of free amino nitrogen and a highest level of higher aliphatic alcohols production during propagation than other preservation methods, which can be attributed to intensive cell growth during propagation. Moreover, the filter paper storage showed a faster accumulation for glycogen and trehalose during propagation, whereas, in particular, lyophilization storage noted a longer adaptation time regarding synthesis of glycogen and trehalose with delayed cell growth. In beer analysis, the filter paper storage formed an increased higher aliphatic alcohols than control. In conclusion, the preservation of filter paper affected positively on yeast growth, viability and beer quality independent on propagation temperature. In addition, in this study, it was obtained that the HICF and Helm-test can be involved as rapid methods for determination of flocculation capacity.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2003.10b
• /
• pp.47-47
• /
• 2003

Plant growth promoting rhizobacteria (PGPR) have been shown to suppress phytopthora blight. This suppression has been related to both microbial antagonism and induced resistance. The PGPR isolates were screened by dual culture plate method and most of the isolates were showed varyinglevels of antagonism. Among the PGPR isolates pyoverdin, pyochelin and salicylic acid producing strains showed the maximum inhibition of mycelial growth of Phytophthora capsici and increased plant growth promotion in red pepper. PGPR isolatesfurther analysed for its ability to induce production of defence related enzymes and chemicals. The activities such as Phenyle alanin ammonia lyase (PAL), Peroxidase (PO), Polyphenol oxidase (PPO) and accumulation of phenolics were observed in PGPR pretreated red pepper plants challenged with Phytophthora capsici. The present study shows that an addition of direct antagonism and plant growth promotion, induction of defense related enzymes involved to enhance resistance against invasion of P. capsici in red pepper.

• Journal of Periodontal and Implant Science
• /
• v.34 no.2
• /
• pp.461-474
• /
• 2004

The purpose of this study was to assess some biological activities of lipopolysaccharides (LPSs) from P. intermedia and P. nigrescens. LPS was prepared by the standard hot phenol-water method. NO production was assayed by measuring the accumulation of nitrite in culture supernatants. $TNF-{\alpha}$ production was determined by enzyme-linked immunosorbent assay. Western blot analysis of iNOS and analysis of reverse transcription (RT)-PCR products were carried out. LPS from P. intermedia demonstrated higher KDO content than those from two stains of P. nigrescens. LPSs from P. intermedia and P. nigrescens were mitogenic for spleen cells of BALB/C mouse. The present study clearly shows that LPSs from P. intermedia and P. nigrescens fully induced iNOS expression and NO production in RAW264.7 cells in the absence of other stimuli. Moreover, LPSs from P. intermedia and P. nigrescens clearly induced $TNF-{\alpha}$ production in RAW264.7 cells. The biological activities of LPS from P. intermedia was found to be comparable to those of P. nigrescens LPS. The ability of LPSs from P. intermedia and P. nigrescens to promote the production of NO and $TNF-{\alpha}$ may be important in the pathogenesis of inflammatory periodontal disease.