Improved antimicrobial activity of Pediococcus acidilactici against Salmonella Gallinarum by UV mutagenesis and genome shuffling

Han, Geon Goo,Song, Ahn Ah,Kim, Eun Bae,Yoon, Seong-Hyun,Bok, Jin-Duck,Cho, Chong-Su,Kil, Dong Yong,Kang, Sang-Kee,Choi, Yun-Jaie Springer-Verlag 2017 Applied microbiology and biotechnology Vol.101 No.13

<P>Pediococcus acidilactici is a widely used probiotic, and Salmonella enterica serovar Gallinarum (SG) is a significant pathogen in the poultry industry. In this study, we improved the antimicrobial activity of P. acidilactici against SG using UV mutation and genome shuffling (GS). To improve antimicrobial activity against SG, UV mutagenesis was performed against wild-type P. acidilactici (WT), and five mutants showed improved antimicrobial activity. To further improve antimicrobial activity, GS was performed on five UV mutants. Following GS, four mutants showed improved antimicrobial activity compared with the UV mutants and WT. The antimicrobial activity of GS1 was highest among the mutants; however, the activity was reduced when the culture supernatant was treated with proteinase K, suggesting that the improved antimicrobial activity is due to a proteinous substance such as bacteriocin. To validate the activity of GS1 in vivo, we designed multi-species probiotics and performed broiler feeding experiments. Groups consisted of no treatment (NC), avilamycin-treated (PC), probiotic group 1 containing WT (T1), and probiotic group 2 containing GS1 (T2). In broiler feeding experiments, coliform bacteria were significantly reduced in T2 compared with NC, PC, and T1. The cecal microbiota was modulated and pathogenic bacteria were reduced by GS1 oral administration. In this study, GS1 showed improved antimicrobial activity against SG in vitro and reduced pathogenic bacteria in a broiler feeding experiment. These results suggest that GS1 can serve as an efficient probiotic, as an alternative to antibiotics in the poultry industry.</P>

Chemical Strain-Relaxation of Single-Walled Carbon Nanotubes on Plastic Substrates for Enhanced Conductivity

Han, Joong Tark,Kim, Jun Suk,Lee, Seung Goo,Bong, Hyojin,Jeong, Hee Jin,Jeong, Seung Yol,Cho, Kilwon,Lee, Geon-Woong American Chemical Society 2011 The Journal of Physical Chemistry Part C Vol.115 No.45

<P>We have demonstrated that the conductivity of single-walled nanotube network films on plastic substrates is enhanced by a simple solvent treatment via chemical welding with aromatic hydrocarbons. The welding effect on the conductivity was confirmed by welding over a surface, the properties of which were controlled by deposition of reduced graphene oxide sheets on the substrate before deposition of the SWCNTs. The correlation between the sheet resistance and the interfacial structure of nanotubes on polyester substrates is further discussed in conjunction with a solvent-induced strain-relaxation of nanotubes and the geometrical change of nanotubes confirmed by atomic force microscopy and Raman spectroscopy after introducing solvents. We observe a clear reversible shift to higher energies in the G-mode band after chemical welding, indicating relaxation of the strain induced by the interface structure at the substrate and network junction.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jpccck/2011/jpccck.2011.115.issue-45/jp207666w/production/images/medium/jp-2011-07666w_0005.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/jp207666w'>ACS Electronic Supporting Info</A></P>

캔위성과 드론을 이용한 기름 유출사고 대응시스템 개발

서한경(Han Kyung Seo),김건형(Geon Hyoung Kim),최형우(Hyung Woo Choi),황경하(Kyung Ha Hwang),김선구(Son-Goo Kim) 한국항공우주학회 2020 한국항공우주학회 학술발표회 논문집 Vol.2020 No.11

순환골재와 고로슬래그 미분말을 사용한 자원순환형 무 시멘트 벽돌의 제조

한천구,김대건,Han, Cheon-Goo,Kim, Dae-Geon 한국건설순환자원학회 2015 한국건설순환자원학회지 Vol.10 No.1

순산소 순환유동층에서 로내 탈황 및 탈질법 적용에 따른 오염물질 거동특성

최경구(Gyung-Goo Choi),나건수(Geon-Soo Na),신지훈(Ji-Hoon Shin),길상인(Sang-In Keel),이정규(Jung-Kyu Lee),허필우(Pil-Woo Heo),윤진한(Jin-Han Yun) 한국청정기술학회 2018 청정기술 Vol.24 No.3

순산소 연소기술은 화력발전에 적용 가능한 유망한 온실가스 감축 기술로 평가되고 있다. 본 연구는 환경적 관점에서 순환유동층을 활용한 순산소 연소조건에 로 내 탈황 및 탈질법을 적용하여 NO 및 SO₂의 거동을 살펴보는 한편, SO₃, NH₃, 그리고 N2O의 발생 경향도 관측하였다. 이를 위해, 연소로 내 석회석 및 요소수를 투입하였다. 로 내 탈황법은 연소가스 내 SO₂ 농도를 ~403에서 ~41 ppm까지 저감하였다. 또한 SO₃ 형성의 주원료인 SO₂가 저감되면서 연소가스 내 SO₃ 농도도 ~3.9에서~1.4 ppm까지 감소되었다. 그러나 석회석 내 CaCO₃가 NO의 발생을 촉진하는 현상도 관측되었다. 연소가스 내 NO 농도는로 내 탈질법을 적용하여 ~26 - 34 ppm까지 저감되었다. 요소수 투입량 증가에 따라 연소가스 내 NH₃ 농도가 증가하여 최대~1.8 ppm으로 나타났으며, N₂O의 농도도 ~61에서 ~156 ppm까지 증가하였다. N₂O 발생량 증가 현상은 요소수의 열분해 과정에서 생성된 HNCO가 N₂O로 전환되어 나타난다. 본 연구의 결과를 통해 로 내 연소가스 세정법을 적용할 경우 NOx 및 SOx의 저감뿐만 아니라, 다른 오염물질의 발생에 대한 주의가 필요할 것으로 보인다. Oxy-fuel combustion is considered as a promising greenhouse gas reduction technology in power plant. In this study, the behaviors of NO and SO₂ were investigated under the condition that in-furnace deNOx and deSOx methods are applied in oxy-fuel circulating fluidized bed combustion condition. In addition, the generation trends of SO₃, NH₃ and N2O were observed. For the purpose, limestone and urea solution were directly injected into the circulating fluidized bed combustor. The in-furnace deSOx method using limestone could reduce the SO₂ concentration in exhaust gas from ~403 to ~41 ppm. At the same experimental condition, the SO₃ concentration in exhaust gas was also reduced from ~3.9 to ~1.4 ppm. This trend is mainly due to the reduction of SO₂. The SO₂ is the main source of the formation of SO₃. The negative effect of CaCO₃ in limestone, however, was also appeared that it promotes the NO generation. The NO concentration in exhaust gas reduced to ~26 - 34 ppm by appling selective non-catalytic reduction method using urea solution. The NH₃ concentration in exhaust gas was appeared up to ~1.8 ppm during injection of urea solution. At the same time, the N₂O generation also increased with increase of urea solution injection. It seems that the HNCO generated from pyrolysis of urea converted into N₂O in combustion atmosphere. From the results in this study, the generation of other pollutants should be checked as the in-furnace deNOx and deSOx methods are applied.

배양한 신생돼지 췌관세포의 증식 및 분화

강성구,서선희,이광우,손호영,손현식,강무일,한제호,유순집,차봉연,고승현,안유배,윤건호,송기호 대한당뇨병학회 2000 Diabetes and Metabolism Journal Vol.24 No.3

Background: Neonatal porcine pancreas is an attractive alternative source for islet transplantation because of its growth potential and availability. Porcine neonatal pancreatic cell clusters(NPCCs) consist mainly of protodifferentiated cells expressing both the duct cell marker pancytokeratin and islet hormones. In this study, we investigated to expand and mature the pancreas duct cells contained in porcine NPCCs with extracellular matrix. Methods: For NPCCs, pancreas obtained from neonatal pigs were minced, digested with collagenase and cultured overnight, Then NPCCs were further disparsed to small cell groups and cultured on HTB-9 extracellular matrix: the tissue attached and formed monolayer patches. At the 3rd and 8th days, tissue was fixed, immunostained for pancytokeratin (panCK), vimentin (VT) and islet hormones. Results: During 5 days culture, the total cell numbers increased 3.2 fold on the matrix, and 1.6 fold on the sticky dish, respectively. Insulin positive cells (Ins+) were 6.0% of total cells at day 3 and increased 1.6 fold in nurnbers at day 8. There was significant increase in DNA content of NPCCs in monolayers on both sticky dishes and HTB-9 matrix. In contrast, insulin content of both groups decreased during culture periods. Until 8 days of culture affer dispersion of porcine NPCC, most duct cells costained with panCK and VT. Conclusion: We observed NPCCs were composed of many of duct cells which were known to be endocrine precursor cells and monolayer culture of NPCC with extracellular matrix resulted in the proliferation and differentiation of pancreatic duct cells

Reference based simulation study of detector comparison for BNCT-SPECT imaging

Kim, Moo-Sub,Shin, Han-Back,Choi, Min-Geon,Monzen, Hajime,Shim, Jae Goo,Suh, Tae Suk,Yoon, Do-Kun Korean Nuclear Society 2020 Nuclear Engineering and Technology Vol.52 No.1

To investigate the optimal detector material for prompt gamma imaging during boron neutron capture therapy, in this study, we evaluated the characteristic regarding radiation reaction of available detector materials using a Monte Carlo simulation. Sixteen detector materials used for radiation detection were investigated to assess their advantages and drawbacks. The estimations used previous experimental data to build the simulation codes. The energy resolution and detection efficiency of each material was investigated, and prompt gamma images during BNCT simulation were acquired using only the detectors that showed good performance in our preliminary data. From the simulation, we could evaluate the majority of detector materials in BNCT and also could acquire a prompt gamma image using the six high ranked-detector materials and lutetium yttrium oxyorthosilicate. We provide a strategy to select an optimal detector material for the prompt gamma imaging during BNCT with three conclusions.

Complete sequence and polymorphisms of female <i>Ruditapes philippinarum</i> (Mollusca: Bivalvia) mitochondria genome

Hwang, Jae Yeon,Han, Geon Goo,Park, Jung Youn,Kim, Eun-Mi,An, Cheul Min,Kang, Jung-Ha,Choi, Yun-Jaie,Kim, Eun Bae Informa UK (Informa Healthcare) 2016 Mitochondrial DNA. Part A Vol.27 No.5

Novel production of natural bacteriocin via internalization of dextran nanoparticles into probiotics

Kim, Whee-Soo,Han, Geon Goo,Hong, Liang,Kang, Sang-Kee,Shokouhimehr, Mohammadreza,Choi, Yun-Jaie,Cho, Chong-Su Elsevier 2019 Biomaterials Vol.218 No.-

<P><B>Abstract</B></P> <P>Recently, probiotics has drawn much attention as an alternative of antibiotics because overuse use of antibiotics has caused widespread bacterial resistance. Given that prebiotics enhance the activity of probiotics, we prepared phthalyl dextran nanoparticles (PDNs) by conjugation of phthalic anhydride with dextran to form a prebiotic and checked its effects on the cellular and antimicrobial properties of the probiotics. First, we found that the internalization of PDNs by probiotics was dependent on temperature, time, and glucose transporters. Internalization of PDNs enhanced the production of antimicrobial peptides by probiotics through self-defense mechanism and resulted in higher antimicrobial activities against Gram-positive and -negative pathogens compared to probiotics themselves. Moreover, pediocin produced by PDN-internalized probiotics was able to suppress pathogenic gut infections and alter the population of gut microbiome <I>in vivo</I>. The enhanced antimicrobial property of <I>Pediococcus acidilactidi</I> internalized with PDNs could decrease the number of pathogens and increase beneficial bacteria species in mice. Furthermore, the composition of gut microbiome was changed, and resulted in preventing reduction of the diversity of the microflora. Our results indicate that PDNs as a new type of prebiotic can regulate probiotic bacterial metabolism, suggesting a new avenue for probiotic modulation and their use in addressing the challenge of bacterial resistance.</P>

Oral Delivery of Probiotics in Poultry Using pH-Sensitive Tablets

( Tao Jiang ),( Hui-shan Li ),( Geon Goo Han ),( Bijay Singh ),( Sang-kee Kang ),( Jin-duck Bok ),( Dae-duk Kim ),( Zhong-shan Hong ),( Yun-jaie Choi ),( Chong-su Cho ) 한국미생물 · 생명공학회 2017 Journal of microbiology and biotechnology Vol.27 No.4

As alternatives to antibiotics in livestocks, probiotics have been used, although most of them in the form of liquid or semisolid formulations, which show low cell viability after oral administration. Therefore, suitable dry dosage forms should be developed for livestocks to protect probiotics against the low pH in the stomach such that the products have higher probiotics survivability. Here, in order to develop a dry dosage forms of probiotics for poultry, we used hydroxypropyl methylcellulose phthalate 55 (HPMCP 55) as a tablet-forming matrix to develop probiotics in a tablet form for poultry. Here, we made three different kinds of probiotics-loaded tablet under different compression forces and investigated their characteristics based on their survivability, morphology, disintegration time, and kinetics in simulated gastrointestinal fluid. The results indicated that the probiotics formulated in the tablets displayed higher survival rates in acidic gastric conditions than probiotics in solution. Rapid release of the probiotics from the tablets occurred in simulated intestinal fluid because of fast swelling of the tablets in neutral pH. As a matrix of tablet, HPMCP 55 provided good viability of probiotics after 6 months under refrigeration. Moreover, after oral administration of probiotics-loaded tablets to chicken, more viable probiotics were observed, than with solution type, through several digestive areas of chicken by the tablets.