• Membrane and Water Treatment
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• 제6권3호
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• pp.189-203
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• 2015

Membrane biofouling impedes wide application of membrane bioreactor (MBR) for wastewater treatment. Recently, quorum sensing (QS) mechanisms are accounted for one of major mechanisms in biofouling of MBRs. In this study, vanillin was applied to investigate reduction of biofouling in MBRs. MBR sludge was analyzed to contain QS signal molecules by cross-feeding biosensor assay and HPLC. In addition, the inhibitory activity of vanillin against bacterial quorum sensing was verified using an indicator strain CV026. The vanillin doses greater than 125 mg/L to 100 mL of MBR sludge showed 25% reduction of biofilm formed on the membrane surfaces. Two MBRs, i.e., a typical MBR as a control and an MBR with vanillin, were operated. The TMP increases of the control MBR were more rapid compared to those of the MBR with the vanillin dose of 250 mg/L. The treatment efficiencies of the two MBRs on organic removal and MLSS were maintained relatively constant. Extracellular polymeric substance concentrations measured at the end of the MBR operation were 173 mg/g biocake for the control MBR and 119 mg/g biocake for the MBR with vanillin. Vanillin shows great potential as an anti-biofouling agent for MBRs without any interference on microbial activity for wastewater treatment.

• The Plant Pathology Journal
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• 제39권3호
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• pp.235-244
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• 2023

Acidovorax citrulli (Ac) is a phytopathogenic bacterium that causes bacterial fruit blotch (BFB) in cucurbit crops, including watermelon. However, there are no effective methods to control this disease. YggS family pyridoxal phosphate-dependent enzyme acts as a coenzyme in all transamination reactions, but its function in Ac is poorly understood. Therefore, this study uses proteomic and phenotypic analyses to characterize the functions. The Ac strain lacking the YggS family pyridoxal phosphate-dependent enzyme, AcΔyppAc(EV), virulence was wholly eradicated in geminated seed inoculation and leaf infiltration. AcΔyppAc(EV) propagation was inhibited when exposed to L-homoserine but not pyridoxine. Wild-type and mutant growth were comparable in the liquid media but not in the solid media in the minimal condition. The comparative proteomic analysis revealed that YppAc is primarily involved in cell motility and wall/membrane/envelop biogenesis. In addition, AcΔyppAc(EV) reduced biofilm formation and twitching halo production, indicating that YppAc is involved in various cellular mechanisms and possesses pleiotropic effects. Therefore, this identified protein is a potential target for developing an efficient anti-virulence reagent to control BFB.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2018년도 춘계학술발표회
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• pp.3-3
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• 2018

For centuries, Panax ginseng Meyer (Korean ginseng) has been widely used as a medicinal herb in Korea, China, and Japan. Ginsenosides are a class of triterpene saponins and recognized as the bioactive components in Korean ginseng. Ginsenosides, which can be classified broadly as protopanaxadiols (PPD), protopanaxatriols (PPT), and oleanolic acids, have been shown to flaunt a vast array of pharmacological activities such as immune-modulatory, anti-inflammatory, anti-tumor, anti-diabetic, and antioxidant effects. In recent years, a number of ginseng and ginsenoside researches have increasingly gained wide attention owing to its unique pharmacological properties. Although good efficacies of ginsenosides have been reported, lack of target specific delivery into tumor sites, low solubility, and low bioavailability due to modifications in gastro-intestinal environments limit their biomedical application in clinical trials. As a result to this major challenge, nanotechnology and drug delivery techniques play a significant role to solve this problematic issue. Thus, we reported the preparation of poly-ethylene glycol (PEG) and glycol chitosan (GC) functionalized to ginsenoside (Compound K and PPD) conjugates via hydrolysable ester bonds with improved aqueous solubility and pH-dependent drug release. In vitro cytotoxicity assays revealed that PEG-CK, and PPD-CK conjugates exhibited lower cytotoxicity compared to bare CK and PPD in HT29 cells. However, GC-CK conjugates exhibited higher and similar cytotoxicity in HT29 and HepG2 cells. Furthermore, GC-CK-treated RAW264.7 cells did not exhibit significant cell death at higher concentration of treatment which supports the biocompatibility of the polymer conjugates. They also inhibited nitric oxide production in lipopolysaccharide (LPS)-induced RAW64.7 cells. In addition to polymer-ginsenoside conjugates, silver (AgNps) and gold nanoparticles (AuNps) have been successfully synthesized by green chemistry using different m. The biosynthesized nanoparticles demonstrated antimicrobial efficacy, anticancer, anti-inflammatory, antioxidant activity, biofilm inhibition, and anticoagulant effect. Special interest on the effective delivery methods of ginsenoside to treatment sites is the focus of metal nanoparticle research.In short, nano-sizing of ginsenoside results in an increased water solubility and bioavailability. The use of nano-sized ginsenoside and P. ginseng mediated metallic nanoparticles is expected to be effective on medical platform against various diseases in the future.

• 대한화장품학회지
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• 제46권1호
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• pp.23-29
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• 2020

피부에는 여러 종의 미생물들이 군집을 이루며 서식하고 있고, 서로 상호작용을 하며 균형을 유지하고 있다. 하지만, 여드름, 건선 및 아토피 피부염과 같은 질병 상태에서는 피부 미생물의 균형이 깨져 건강한 피부와는 다른 미생물 군집 구성을 보인다. 피부 미생물 군집 구성의 조절은 이러한 피부 질환에 대한 잠재적인 치료 방법이 될 수 있다. Quorum sensing (QS)은 세포간 전달인자로, QS을 조절하면 유해균의 바이오필름 형성이나 효소 분비등을 억제할 수 있고, 이 역시 피부 미생물 군집 구성에 영향을 준다. 이번 연구에서는 아모레퍼시픽의 특허 성분인 유산균 발효 용해물(Lactobacillus plantarum APsulloc 331261, KCCM 11179P 이용)의 QS억제능력 및 피부 유익균과 피부 유해균의 생장에 미치는 영향을 확인하였다. 유산균 발효 용해물 10 ㎍/mL 처리시, QS에 의해 제어되는 Chromobacterium violaceum의 자주색 안료 생산을 대조군 대비 27.4% 감소시켰다. 또 피부 유익균인 Staphylococcus epidermidis의 생장을 대조군 대비 12% 증가 시켰고, 피부 유해균인 Pseudomonas aeruginosa의 생장을 38.5% 감소, 바이오필름 형성을 17.7% 감소시켰다. S. epidermidis를 같은 속(genus)에 포함되어 있는 대표적인 피부 유해균 Staphylococcus aureus와 함께 공배양 하였을 때 S. epidermidis의 생장은 대조군 대비 134% 증가시켰고, S. aureus의 생장은 13% 억제시켰다. 이러한 결과들을 종합하였을 때 L. plantarum APsulloc 331261을 이용한 발효 용해물은 피부 미생물의 균형을 조절해 줄 수 있는 화장품 원료로 유용하게 사용 될 수 있다고 사료된다.

• Journal of Periodontal and Implant Science
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• 제46권2호
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• pp.84-95
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• 2016

Purpose: The objective of this study was to investigate the effect of a dietary flavonoid, kaempferol, which has been shown to possess antiallergic, anti-inflammatory, anticarcinogenic, and antioxidant activities on the periodontium by histomorphometric analysis and on gingival tissue matrix metalloproteinase-1 (MMP-1), MMP-8, and tissue inhibitor of metalloproteinase-2 (TIMP-2) by biochemical analysis of rats after experimental periodontitis induction. Methods: Sixty Wistar rats were randomly divided into six groups of ten rats each, and silk ligatures were placed around the cervical area of the mandibular first molars for 15 days, except in the healthy control rats. In the experimental periodontitis groups, systemic kaempferol (10 mg/kg/2d) and saline were administered by oral gavage at two different periods (with and without the presence of dental biofilm) to all rats except for the ten non-medicated rats. Alveolar bone area, alveolar bone level, and attachment level were determined by histomorphometric analysis, and gingival tissue levels of MMP-1, MMP-8, and TIMP-2 were detected by biochemical analysis. Results: Significantly greater bone area and significantly less alveolar bone and attachment loss were observed in the kaempferol application groups compared to the control groups (P<0.05). In addition, gingival tissue MMP-1 and -8 levels were significantly lower in the kaempferol application groups compared to the control groups and the periodontitis group (P<0.001). There were no statistically significant differences in TIMP-2 levels between the kaempferol and saline application groups (P>0.05). Conclusions: Kaempferol application may be useful in decreasing alveolar bone resorption, attachment loss, and MMP-1 and -8 production in experimental periodontitis.

• Molecules and Cells
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• 제28권5호
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• pp.447-453
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• 2009

The quorum sensing (QS) inhibitors that antagonize TraR, a receptor protein for N-3-oxo-octanoyl-L-homoserine lactones (3-oxo-C8-HSL), a QS signal of Agrobacterium tumefaciens were developed. The structural analogues of 3-oxo-C8-HSL were designed by in silico molecular modeling using SYBYL packages, and synthesized by the solid phase organic synthesis (SPOS) method, where the carboxamide bond of 3-oxo-C8-HSL was replaced with a nicotinamide or a sulfonamide bond to make derivatives of N-nicotinyl-L-homoserine lactones or N-sulfonyl-L-homoserine lactones. The in vivo inhibitory activities of these compounds against QS signaling were assayed using reporter systems and compared with the estimated binding energies from the modeling study. This comparison showed fairly good correlation, suggesting that the in silico interpretation of ligand-receptor structures can be a valuable tool for the pre-design of better competitive inhibitors. In addition, these inhibitors also showed anti-biofilm activities against Pseudomonas aeruginosa.

• Advances in nano research
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• 제5권2호
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• pp.127-140
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• 2017

Metal nanoparticles have been intensively studied within the past decade. Nano-sized materials have been an important subject in basic and applied sciences. Zinc oxide nanoparticles have received considerable attention due to their unique antibacterial, antifungal, and UV filtering properties, high catalytic and photochemical activity. In this study, microbiological aspects of scale formation in PVC pipelines bacteria and fungi were isolated. In the emerging issue of increased multi-resistant properties in water borne pathogens, zinc oxide (ZnO) nanoparticle are being used increasingly as antimicrobial agents. Thus, the minimum bactericidal concentration (MBC) and minimum fungal concentration of ZnO nanoparticles towards pathogens microbe were examined in this study. The results obtained suggested that ZnO nanoparticles exhibit a good anti fungal activity than bactericidal effect towards all pathogens tested in in-vitro disc diffusion method (170 ppm, 100 ppm and 30 ppm). ZnO nanoparticles can be a potential antimicrobial agent due to its low cost of production and high effectiveness in antimicrobial properties, which may find wide applications in various industries to address safety issues. Stable ZnO nanoparticles were prepared and their shape and size distribution characterized by Dynamic light scattering (35.7 nm) and transmission electron microscopic TEM study for morphology identification (20 nm), UV-visible spectroscopy (230 nm), X-ray diffraction (FWHM of more intense peak corresponding to 101 planes located at $36.33^{\circ}$ using Scherrer's formula), FT-IR (Amines, Alcohols, Carbonyl and Nitrate ions), Zeta potential (-28.8). The antimicrobial activity of ZnO nanoparticles was investigated against Bacteria and Fungi present in drinking water PVC pipelines biofilm. In these tests, Muller Hinton agar plates were used and ZnO nanoparticles of various concentrations were supplemented in solid medium.

• Journal of Microbiology and Biotechnology
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• 제33권9호
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• pp.1149-1161
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• 2023

Changes in the gut microbiome cause recolonization by pathogens and inflammatory responses, leading to the development of intestinal disorders. Probiotics administration has been proposed for many years to reverse the intestinal dysbiosis and to enhance intestinal health. This study aimed to evaluate the inhibitory effects of two newly designed probiotic mixtures, Consti-Biome and Sensi-Biome, on two enteric pathogens Staphylococcus aureus and Escherichia coli that may cause intestinal disorders. Additionally, the study was designed to evaluate whether Consti-Biome and Sensi-Biome could modulate the immune response, produce short-chain fatty acids (SCFAs), and reduce gas production. Consti-Biome and Sensi-Biome showed superior adhesion ratios to HT-29 cells and competitively suppressed pathogen adhesion. Moreover, the probiotic mixtures decreased the levels of pro-inflammatory cytokines, such as tumor necrosis factor-α, interleukin (IL)-6 and IL-1β. Cell-free supernatants (CFSs) were used to investigate the inhibitory effects of metabolites on growth and biofilms of pathogens. Consti-Biome and Sensi-Biome CFSs exhibited antimicrobial and anti-biofilm activity, where microscopic analysis confirmed an increase in the number of dead cells and the structural disruption of pathogens. Gas chromatographic analysis of the CFSs revealed their ability to produce SCFAs, including acetic, propionic, and butyric acid. SCFA secretion by probiotics may demonstrate their potential activities against pathogens and gut inflammation. In terms of intestinal symptoms regarding abdominal bloating and discomfort, Consti-Biome and Sensi-Biome also inhibited gas production. Thus, these two probiotic mixtures have great potential to be developed as dietary supplements to alleviate the intestinal disorders.

• 멤브레인
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• 제31권1호
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• pp.16-34
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• 2021

물 공급은 늘어나는 담수 수요와 다르게 줄어들고 있다. 담수의 수요를 충당하기 위해서 나노여과법은 가장 효율적이고 경제적인 방법이라고 할 수 있다. 해수담수화를 위한 나노여과법의 일반적인 방법으로는 나노여과 멤브레인을 이용한 역삼투압 방식이다. 하지만 기존의 멤브레인들은 주요 특성인 안정성, 경제성, 그리고 살균 및 방오특성이 부족하다. 기존의 나노여과 멤브레인을 향상시키기 위해서 친수성과 방오성이 높은 흑연 산화물이 가장 향상성이 높으며 널리 연구되고 있는 재료이다. 멤브레인 변형은 다른 레이어에 적용될 수 있다. 얇은 막으로 이루어진 멤브레인은 다른 세 레이어로 구성되어 있다, 표면의 폴리아미드 레이어, 기공 레이어, 그리고 전체적인 구조를 구성하는 지원 직물이다. 정삼투압 토한 에너지 효율적인 해수담수화 방식이지만 효율이 생물 오염 때문에 떨어진다. 산화그래핀 결합은 향균 기능을 향상할 수 있으며 멤브레인 표면에 바이오필름 생성을 억제할 수 있다. 압력지연삼투는 해수에서 청정에너지를 발전시키는 최고의 방법 중 하나이다. 멤브레인의 생물 오염은 합성 폴리머 멤브레인의 합성 레이어에 산화 그래핀을 합성하여 줄일 수 있다. 나노여과 멤브레인을 개량하는 여러 연구가 각자의 장단점을 가지고 이루어지고 있다. 이 보고서는 나노여과 멤브레인의 개량, 성질, 그리고 성능에 대해 논의한다.