Antimicrobial Activity of Low Molecular Weight Chitosan derived from the Hydrolysis of High Molecular Weight Chitosan by A Chitosanolytic Microorganism Bacillus subtillis JH-1122

Bon-Geun Koo,Gu Baek,Min Jung Kim,Seo Yoon Shin,Yong Il Park,Jae Kweon Park 한국당과학회 2011 한국당과학회 학술대회 Vol.2011 No.1

Chitinolytic and chitosanolytic microorganisms are widely distributed in nature. Biological and enzymatic activities of these enzymes are applied to produce hydrolytic oligosaccharides which have various biological functions involved in anticancer, antimicrobial activities, immune-stimulating activities and so on. In the present study, we describe the biological characteristics including the diversity based on 16S rDNA sequence analysis, production of chitosanase and its hydrolysates, and enzyme activities. Among 15 species of chitosanolytic microorganisms isolated in this study, one named as Bacillus subtilis JH-1122 based on 16s rDNA sequence homology search has shown the highest similarity with most of sub-species of Bacillus. Various sizes of chitosan hydrolysates (Low Molecular Weight Chitosan, LMWC) ranging from 3 to 60 kDa were prepared to assess the effect of molecular weight on antimicrobial activity by enzymatic digestion of chitosan using chitosanase isolated and partially purified from the culture medium of Bacillus subtillis JH-1122. Especially it has shown the higher antimicrobial activity toward antibiotics resistant microorganisms such as Escherichia coli, methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa. These results suggest that LMWC may be a predominant factor either directly or indirectly affecting on broad antimicrobial activities.

Potential Anti-photoaging Effect of Amino Sugar

( Bon Geun Koo ),( Gu Baek ),( Yeon Woo Kim ),( Ji Min Park ),( Min Ju Kim ),( Hyun Seo Ko ),( Jae Kweon Park ) 한국키틴키토산학회 2012 한국키틴키토산학회지 Vol.17 No.2

The anti-photoaging activity of amino sugar was measured by monitoring the survival rate toward a bacterial species Serratia marcescens. Cells incubated in liquid and solid culture medium containing various sugars were irradiated under UV 254 nm or 365 nm. Among sugars tested in this study, relatively high photo-protective activity in the presence of amino sugars such as glucosamine, mannosamine, and galactosamine on cells irradiated under UV 365 nm were observed incubated in liquid culture medium compared to other neutral sugars tested. Especially, glucosamine has displayed the highest photo-protective activity (75%) estimated based on the growth recovery of cells irradiated under UV 365 nm. On the other hands, neutral sugar including glucose, mannose and galactose showed the marginal photo-protective effect on cells irradiated under UV 365 nm. However, both amino sugars and neutral sugars displayed neither photo-protective activities on cells incubated in liquid nor solid agar medium under UV 254 nm. Our results indicate that amino sugars has shown selective absorbing activities toward UV 365 nm and are useful as potentially bioactive anti-photoaging materials in cosmeceutical and pharmaceutical industries.

Evaluation of Antioxidative Activities of Polymeric Carbohydrates

( Bon Geun Koo ),( Gu Baek ),( Jin Young Park ),( Ji Min Park ),( Min Ju Kim ),( Hyun Seo Ko,),( Byung Jae Ahn ),( Jae Kweon Park ) 한국키틴키토산학회 2012 한국키틴키토산학회지 Vol.17 No.3

The antioxidant capabilities of various polysaccharides including alginate, β-glucan, chitosan, fucoidan and hyaluronate were investigated using three established assays: 2,2-diphenyl-1-picryhydrazyl (DPPH) radical scavenging, ferric reducing antioxidant power (FRAP), and superoxide dismutases (SODs) which are metalloenzymes that catalyze the dismutation of the superoxide anion to hydrogen peroxide and molecular oxygen. The DPPH radical scavenging assay revealed that among the five polysaccharides tested in this study, hyaluronic acid had relatively high antioxidant activity. However, low molecular weight chitooligosaccharides, consisting of glucosamine (GlcN) n, n = 6-9, exhibited slightly higher radical scavenging activity than hyaluronic acid. Interestingly, no DPPH radical scavenging activity was observed from the high molecular weight chitosan. On the contrary, in the FRAP activity measurements, high molecular weight chitosan showed the significant level of activity compared to the chitooligosaccharides, which has shown the similar activity of fucoidan and hyaluronic acid, although it was too marginal. Subsequently, fucoidan has shown the most significant antioxidant activity in SOD assay. These results suggest that antioxidant activity obviously depends on the molecular weight and their structural component as a key factor involved in each reaction mechanisms.

Effects of the Molecular Weight and the Degree of Deacetylation of Chitosan Oligosaccharides on Antitumor Activity

Bon Geun Koo,Jae Kweon Park 한국당과학회 2012 한국당과학회 학술대회 Vol.2012 No.1

Effects of the degree of deacetylation (DDA) and the molecular mass of chitosan oligosaccharides (CTS-OS), obtained from the enzymatic hydrolysis of high molecular weight chitosan (HMWC), on antitumor activity was explored. The DDA and molecular weights of CTS-OS were determined by matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-TOF MS) analysis. The CTS-OS were found to be a mixture of mainly dimers (18.8%), trimers (24.8%), tetramers (24.9%), pentamers (17.7%), hexamers (7.1%), heptamers (3.3%), and octamers (3.4%). The CTS-OS were further fractionated by gel-filtration chromatography into two major fractions: (1) COS, consisting of glucosamine (GlcN)

Isolation and characterization of Penicilliumjanthinellum LPB-01 producing dual chitinolytic and chitosanolytic enzymes

Bon Geun Koo,Gu Baek,Yeon Woo Kim,Min Kyun Ko,Jae Kweon Park 한국당과학회 2012 한국당과학회 학술대회 Vol.2012 No.1

키틴분해 곰팡이 Penicillium janthinellum LPB-01의 생물학적 특성 연구

구본근 ( Bon Geun Koo ),백구 ( Gu Baek ),신서윤 ( Seo Yoon Shin ),김민정 ( Min Jung Kim ),김태준 ( Tae Jun Kim ),선준홍 ( Jun Hong Seon ),전소영 ( So Young Jeon ),임다영 ( Da Young Im ),박지민 ( Ji Min Park ),박제권 ( Jae Kweon P 한국키틴키토산학회 2011 한국키틴키토산학회지 Vol.16 No.4

The aim of the present study is to define the characteristics and biological activities of chitinolytic fungus Penicillium janthinellum LPB-01. Chitinolytic activity was determined using 4-nitrophenyl N-acetyl-β-D-glucosaminide (about 417 pmol/ μg/min) and 4-Nitrophenyl N,N`-diacetyl-β-D-chitobiosides (665 pmol/μg/min) as substrates, and reducing sugar assay. P. janthinellum LPB-01 actively degrades chitin and sulfated chitin producing chitooligosacharides. These results revealed that P. janthinellum LPB-01 is suitable for depolymerizing chitinous materials including sulfated chitin to produce low molecular weight chitooligosacharides. In addition, significant anti-oxidant effects of culture supernatant of P. janthinellum LPB-01 cultured in different conditions were determined by using 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical. Based on these results, we concluded that P. janthinellum LPB-01 can be used as a produced for potentially active materials.

키토산 분해 곰팡이 Penicillium janthinellum LPB-01의 키토산 분해 특성 연구

구본근 ( Bon Geun Koo ),김우중 ( Woo Jung Kim ),신서윤 ( Seo Yoon Shin ),김민정 ( Min Jung Kim ),백구 ( Gu Baek ),김태준 ( Tae Jun Kim ),박제권 ( Jae Kweon Park ) 한국키틴키토산학회 2011 한국키틴키토산학회지 Vol.16 No.3

본 연구에서는 공기 중으로부터 분리 동정한 곰팡이의 키토산 분해능과 키토산 분해 산물에 대해 조사하였다. 26S rDNA 염기서열결정 및 상동성 비교에 따라 P. janthinellum LPB-01라 잠정적으로 명명하였으며, 이 곰팡이는 키토산을 분해하여 chitooligosaccharides를 생산하는 키토산 분해능을 갖는 곰팡이로 확인되었다. 곰팡이의 키토산 분해능을 분석하기 위해 고체상 그리고 액상의 가수분해산물의 환원당 측정법, TLC, HPLC 등을 이용하여 확인하였다. 하지만 키토산 분해 활성을 갖는 단백질을 SDS-PAGE를 통해 검출하지 못했다. 이러한 결과를 바탕으로 P. janthinellum LPB-01는 아마도 구조적인 키토산 분해효소를 갖고 있을 것으로 사료된다. 특이적으로 장시간 반응시킨 후 키토산 분해의 최종 산물을 TLC와 HPAEC로 분석한 결과, 최종산물은 glucosamine이 아닌 glucose로 확인되었다. 현 상태에서는 분해기작과 보다 복잡한 이화작용 및 이에 관여하는 효소들의 기능에 대해 명확히 밝힐 근거자료를 확보하지 못했다. 하지만 키토산 분해 곰팡이 P. janthinellum LPB-01은 키토산 분해효소 활성은 물론 특이적으로 glucosamine을 glucose로 전환시키는 deaminase의 효소활성이 추정된다. 이러한 결과를 바탕으로 본 연구에 이용된 곰팡이는 키토산으로부터 chitooligosaccharides를 생산할 수 있음과 더불어 최종산물은 glucose로서 glucosamine을 glucose로 전환시키는 효소활성을 갖는 것으로 확인되어, 본 연구에서 확보한 곰팡이는 키토산 저분자화에 따른 chitooligosaccharides의 대량생산은 물론 키토산 이화작용을 규명하는 생물학적인 도구로 사용될 수 있는 가능성을 확인하였다. In this study, we investigated the abililty for the degradation of chitosan by fungus isolated from air environment. The fungus that is tentatively named as Penicillium janthinellum LPB-01 based on 26S rDNA sequence analysis and homology search has ability to degrade chitosan to produce chitooligosaccharides. Chitosanolytic activity determined by reducing sugar assay, TLC, and HPLC analysis was confirmed that P. janthinellum LPB-01 actively depolymerize chitosan in both solid-phase and liquidphase. However, no protein was observed in SDS-PAGE. These results exhibited that P. janthinellum LPB-01 may have constructive chitosanolytic enzyme facing outward of the cell walls. Unexpectedly, however, end-product of the reaction of chitosan with P. janthinellum LPB-01 was defined by HPLC to glucose. In the present study, we can not provide much clear answer why, but it is so worthy to note that there is a so complicated mechanism to catabolite chitosan including chitosanolytic enzyme and deaminase which might be specific for transfer glucosamine to glucose. Nevertheless, these results show that the fungus is suitable for degrading chitooligosaccharides and producing glucose as by product, suggesting the potential use of fungus as biological tool for the catabolic cascade of chitosan.

YOLO 기반 과실 분류 모델 설계 및 구현

구본근 ( Bon-geun Koo ),정다운 ( Da-un Jeong ),김지영 ( Ji-young Kim ),최지원 ( Ji-won Choi ),박장우 ( Jang-woo Park ),조용윤 ( Young-yun Cho ),신창선 ( Chang-sun Shin ) 한국정보처리학회 2021 한국정보처리학회 학술대회논문집 Vol.28 No.2

일반적으로, 과실 재배 농가에서의 과실 분류 작업은 많은 노동력을 필요로 한다. 최근 코로나19 방역조치로 외국인 근로자 입국 제한으로 인해 농가에서는 인력 수급에 어려움을 겪고 있다. 본 연구에서는 이러한 농가 피해 상황을 해소하고 수급 문제를 해결하기 위해 YOLO 기반 과실 분류 모델 설계 및 구현을 소개한다. 본 모델을 기반으로 여러 과실 중 사과에 적용하여 인력이 많이 동원되는 선별과정을 YOLO의 객체 인식을 통해 해결하고 적은 비용으로 효율성 있는 분류 모델을 구축한다.

태권도 품새 수련이 신체구성, 체력, 폐기능 및 혈액성분에 미치는 영향

구본칠(Bon-Chil Koo),남정렬(Jeoung-Ryul Nam),서재근(Jae-geun Seo) 한국코칭능력개발원 2009 코칭능력개발지 Vol.11 No.3

중복 부위 검사 시 선량감소를 위한 Resolution과 Filter의 변화에 따른 화질평가

구본승(Bon Seung Koo),여상근(Sang geun Yeo),대창민(Chang Min Dae),민관홍(Kwan Hong Min),김성룡(Sung Ryong Kim),조평곤(Pyong Kon Cho) 대한CT영상기술학회 2011 대한CT영상기술학회지 Vol.13 No.1

목 적 최근 교통사고, 급성중증 환자의 증상에 따른 빠르고 정확한 진단을 위해서, 여러 가지 CT 검사가 동시에 발행되고 있다. 하지만, 중복되는 검사 범위라 할지라도 서로 다른 스캔 프로토콜로 검사하기 때문에 환자의 피폭선량은 증가하고 있다. 따라서, 본 연구의 목적은 다양한 resolution과 filter 변화에 따른 영상의 화질을 평가하고, 적절한 프로토콜을 임상에 적용하여 중복되는 검사의 감소에 따른 선량감소효과에 관한 연구를 하고자 한다. 대상 및 방법 CT 장비는 256-MDCT(Brilliance iCT, Philips health care, USA)로 진행하였으며 영상의 화질평가는 AAPM 팬텀(Model 610, Nuclear Association LTD, USA)과 philips system head phantom을 이용하고, Extended Brilliance Workspace(Version 4.0, Philips Medical Systems, Netherlands)로 측정하였다. Resolution과 filter가 화질에 미치는 영향을 알아보기 위해서, scan parameter를 128 * 0.625 beam collimation, 120 kVp, 250 mAs, 0.5 sec, 250 mm FOV, 5 mm slice thickness로 동일하게 적용하였고, resolution는 standard, high, ultrahigh로, filter는 A, B, C, D, EB, EC, UA, UB, UC, YC, YD, YE, YF 등으로 바꿔가면서 재구성한 영상으로 CT 감약계수, 노이즈, 균일도, 직선성, 공간분해능, MTF(50%, 10%)를 측정하여 화질을 평가하였다. 임상 적용에 따른 평가는 brain CT와 facial CT 3D를 단 한번의 스캔으로 검사한 환자를 대상으로, 영상의 화질을 정량적으로 평가하였고, 장비에서 제공하는 total DLP를 유효선량으로 계산하여 피폭선량을 평가하였다. 결 과 AAPM 팬텀의 영상평가에서 CT 감약계수는 resolution의 종류에 따라 6.5~-0.8 HU로 다양하게 분포하였고, 노이즈는 7.4~36.7 HU까지, 공간 분해능은 1.0~0.6 mm까지 구별하였고, MTF 50%는 3.6~5.3 lp/cm까지, MTF 10%는 6.4~8.5 lp/cm까지 standard에서 ultrahigh resolution으로 갈수록 공간주파수가 높게 평가되었다. 동일한 resolution에서 filter의 변화에 따른 화질 평가에서는 CT 감약계수만 filter의 종류에 따라 다양하게 분포하였고, 그외 노이즈, 공간 분해능, MTF 값은 filter가 smooth에서 sharp로 증가할수록 함께 증가하였다. 필립스 QA 팬텀으로 brain CT검사 시 사용되는 standard resolution과 UB filter를 이용하여 얻은 영상을 평가한 것은 high resolution과 UA또는 UB filter를 사용하여 얻은 영상과 가장 유사한 값을 보였다. 임상에 적용하여 평가한 결과는 high resolution과 UB filter를 사용시 임상적 적용이 높게 평가되었고, 기존에 검사해오던 brain CT영상과는 큰 차이를 느끼지 못했다. 뿐만 아니라, 선량 평가에서도 brain의 중복 검사를 피하기 위해서, 한번에 검사한 경우의 DLP는 977.1±22.4 mGyㆍcm, 유효선량은 2.2±0.1 mSv로 전체적으로 약 31.25%의 선량감소효과를 나타냈다. 결 론 서로 다른 프로토콜로 검사하는 brain CT와 facial CT 같이 중복되는 부위를 갖는 검사들이 동시에 발행될 경우 resolution과 filter에 따른 영상의 질적 차이를 정확히 이해하고 응용하여, 최적의 프로토콜을 사용함으로써, 중복되는 CT 검사의 수를 감소시켜서 환자의 피폭선량을 최소화할 수 있도록 해야 한다. Ⅰ. Purpose For fast and accurate diagnosis, various CT order are applied at the same time. But, radiation dose of patient is increased because the same body parts are studied with different CT protocol. The purpose of this study is to investigate image quality and the change of radiation dose according to the various resolution and filter. Ⅱ. Materials and Methods 256-MDCT(Brilliance iCT, Philips health care, Cleveland. OH, USA) was used in this study. In phantom study, image quality of AAPM and Philips QA phantom was evaluated by EBW. To evaluate the effects on the quality by resolution and filter, We measured the CT attenuation coefficient, noise, uniformity, linearity, spatial resolution, MTF in reconstructed image depending on the type of resolution and filter. The kind of resolution are standard, high, ultrahigh and the filter are composed of A, B, C, D, EB, EC, UA, UB, UC, YC, YD, YE, YF. The patient were studying brain CT and facial CT at the same time. For clinical applications, image quality was assessed quantitatively and radiation dose was measured with total DLP provided by CT modality. Ⅲ. Results 1. CT attenuation coefficient was distributed 6.5~-0.8 HU and noise was 7.4~36.7 HU. Spatial resolution was distinguished 1.0~0.6 mm. MTF 50% was evaluated 3.6~5.3 lp/mm, and MTF 10% was evaluated 6.4~8.5 lp/cm. In the same resolution, Measurement of Noise, Spatial resolution, MTF value are increasing from smooth to sharp except CT attenuation coefficient. 2. Brain image obtained with standard resolution and UB filter is similar to image with high resolution and UA or UB. 3. In the results of clinical application, brain image with high resolution and UB filter was effective. There were no significant difference compared to before. In addition, the dose was reduced by 31.25%. Ⅳ. Conclusion If we examine the same body part with a different protocol, we should study the patient with appropriate protocol in consideration of the dose and image quality. Therefore We must know the relationship between various resolution and filter. We should reduce the number of scan the same region in order to reduce the effective dose.