Conversion Characteristics of Chemical Constituents in Liriodendron tulipifera and Their Influences on Biomass Recalcitrance during Acid-Catalyzed Organosolv Pretreatment

( Ki-seob Gwak ),( Junho Shin ),( Chae-hwi Yoon ),( In-gyu Cho ) 한국목재공학회 2024 목재공학 Vol.52 No.2

The conversion characteristics of the major components of Liriodendron tulipifera were investigated during acid-catalyzed organosolv pretreatment. Glucan in L. tulipifera was slowly hydrolyzed, whereas xylan was rapidly hydrolyzed. Simultaneous hydrolysis and degradation of xylan and lignin occurred; however, after complete hydrolysis of xylan at higher temperatures, lignin remained and was not completely degraded or solubilized. These conversion characteristics influence the structural properties of glucan in L. tulipifera. Critical hydrolysis of the crystalline regions in glucan occurred along with rapid hydrolysis of the amorphous regions in xylan and lignin. Breakdown of internal lignin and xylan bonds, along with solubilization of lignin, causes destruction of the lignin-carbohydrate complex. Over a temperature of 160℃, the lignin that remained was coalesced, migrated, and re-deposited on the surface of pretreated solid residue, resulting in a drastic increase in the number and content of lignin droplets. From the results, the characteristic conversions of each constituent and the changes in the structural properties in L. tulipifera effectively improved enzymatic hydrolysis in the range of 140℃-150℃. Therefore, it can be concluded that significant changes in the biomass recalcitrance of L. tulipifera occurred during organosolv pretreatment.

SCB 액비 처리에 의한 백합나무의 생장 증진

곽기섭(Ki-Seob Gwak),김호용(Ho-Yong Kim),유근옥(Keun-Ok Ryu),최형순(Hyung-Soon Choi),조도현(Do-Hyun Cho),김판기(Pan-Gi Kim),최인규(In-Gyu Choi) 한국산림바이오에너지학회 2009 산림바이오에너지 Vol.28 No.1

SCB (Slurry Composting and Biofiltration) 액비 처리에 의한 백합나무의 생장 증진 효과를 확인하기 위하여 무 처리구, 관수 처리구, SCB 액비 처리구로 시험구를 설정하여 상대생장량, 엽면적, 건중량, 엽록소 함량, 토양 및 백합나무 가지, 잎의 무기원소 함량을 각각 분석하였다. 무 처리구, 관수 처리구에 비해 SCB 액비 처리구에서 상대 생장량, 엽면적, 건중량, 엽록소 함량이 높게 나타났으며, 관수 처리구가 무 처리구보다 높은 경향을 보여준 결과로부터 SCB에 함유된 양료 성분과 수분 함량이 백합나무의 생장에 중요한 인자일 것이라고 사료되었다. 보다 정확한 원인을 구명하기 위해 토양 및 백합나무 가지, 잎의 무기원소 함량을 측정하였다. 토양과 백합나무 잎의 총 질소, 총인, 칼륨 함량이 세 처리구 중 SCB 액비 처리구에서 높게 나타났는데, 이는 SCB 액비 처리에 의해 토양 내의 질소, 인, 칼륨 함량이 증가하였고, 백합나무 뿌리를 통하여 잎까지 이동된 것을 의미한다. 질소, 인, 칼륨은 식물체의 주요 구성성분 및 대사 작용에 사용되기 때문에 SCB 액비 처리로 인하여 백합나무에 양료원소가 공급되어 생장이 증가한 것으로 사료되었다. 이들 결과는 바이오매스 생산의 증가를 의미하는 것이며, 백합나무의 바이오순환림 조성 시 효율적인 바이오매스 생산에 기여할 것으로 사료된다. To evaluate the growth improvement of Liriodendron tulipifera through SCB manure treatment, three experimental sectors of the control, water and SCB manure treatments were set up, and relative growth rate, leaf area, leaf dry weight, chlorophyll content, and inorganic contents of soil, twig and leaf were measured. Relative growth rate, leaf area and leaf dry weight on SCB manure treatment were higher than those on the control and water treatment. Based on the results of higher relative growth rate, leaf area and leaf dry weight on water treatment than those on the control, it seemed that nutrient and water contents in the soil were important factors for the growth of L. tulipifera. To investigate the factor for the tree growth, inorganic contents of soil, twig and leaf were analyzed. The N, P and K contents of soil and leaf on SCB manure treatment were the highest level among three experimental sectors. These results meant that the N, P and K contents of soil through SCB manure treatment increased, and these components were transported to the leaf through the root. As the N, P and K were main components of the plant, and important to tree metabolism actions, the beneficial components were supplied to L tulipifera by SCB manure treatment, and its growth was improved. This result suggested that the growth improvement of L tulipifera through SCB manure treatment caused the increase of biomass production, and might contribute to effective biomass production of L tulipifera forestation for bioenergy production.

피부사상균에 대한 편백정유의 Mono-및 Sesquiterpene 항진균 활성 비교

곽기섭 ( Ki Seob Gwak ),박미진 ( Mi Jin Park ),정의배 ( Eui Bae Jeung ),장제원 ( Je Won Chang ),최인규 ( In Gyu Choi ) 한국목재공학회 2006 목재공학 Vol.34 No.3

Biological Pretreatment of Softwood Pinus densiflora by Three White Rot Fungi

이재원,Ki-Seob Gwak,Jun-Yeong Park,Mi-Jin Park,Don-Ha Choi,Mi Kwon,최인규 한국미생물학회 2007 The journal of microbiology Vol.45 No.6

The effects of biological pretreatment on the Japanese red pine Pinus densiflora, was evaluated after exposure to three white rot fungi Ceriporia lacerata, Stereum hirsutum, and Polyporus brumalis. Change in chemical composition, structural modification, and their susceptibility to enzymatic saccharification in the degraded wood were analyzed. Of the three white rot fungi tested, S. hirsutum selectively degraded the lignin of this sortwood rather than the holocellulose component. After eight weeks of pretreatment with S. hirsutum, total weight loss was 10.7%, while lignin loss was the highest at 14.52% among the tested samples. However, holocellulose loss was lower at 7.81% compared to those of C. lacerata and P. brumalis. Extracelluar enzymes from S. hirsutum showed higher activity of ligninase and lower activity of cellulase than those from other white rot fungi. Thus, total weight loss and changes in chemical composition of the Japanese red pine was well correlated with the enzyme activities related with lignin- and cellulose degradation in these fungi. Based on the data obtained from analysis of physical characterization of degraded wood by X-ray Diffractometry (XRD) and pore size distribution, S. hirsutum was considered as an effective potential fungus for biological pretreatment. In particular, the increase of available pore size of over 120 nm in pretreated wood powder with S. hirsutum made enzymes accessible for further enzymatic saccharification. When Japanese red pine chips treated with S. hirsutum were enzymatically saccharified using commercial enzymes (Cellulclast 1.5 L and Novozyme 188), sugar yield was greatly increased (21.01%) compared to non-pretreated control samples, indicating that white rot fungus S. hirsutum provides an effective process in increasing sugar yield from woody biomass.

선박 유압공급 장치용 사판식 유압 피스톤 펌프 내부 유동해석에 관한 연구

이중섭(Chung-Seob Yi),이정실(Jeong-Sil Lee),임종학(Jong-hak Lim),곽범섭(Beom-Seop Gwak),이호성(Ho Seong Lee),송철기(Chul Ki Song) 한국기계가공학회 2022 한국기계가공학회지 Vol.21 No.1

In this paper, a flow analysis of a swash-plate type hydraulic piston pump installed on a hydraulic flow supply system for marine vessels is presented. A model and governing equations for computational fluid dynamics (CFD) analyses of swash-plate type hydraulic piston pumps were built, and simulation results regarding the internal flow field of the pump were obtained. By analyzing the internal flow of the swash-plate type hydraulic piston pump, we can confirm the time-dependent stroke of each piston as the pump rotates. We also verified that by analyzing the pulsating flow against the slope of the swash plate, the simulation results match well with the experimental results. The natural frequency of the system was computed to be approximately 380 Hz by applying and analyzing the fast Fourier transform (FFT) of each swash plate slope evaluated.

Characterization of by-products from organosolv pretreatments of yellow poplar wood (Liriodendron tulipifera) in the presence of acid and alkali catalysts

곽기섭,구본욱(Gwak, Ki-Seob),박나현(Park, Na-Hyun),정한섭(Jeong, Han-Seob),최준원(Choi, Joon-Weon),여환명(Yeo, Hwan-Myeong),최인규(Choi, In-Gyu) 한국신재생에너지학회 2009 한국신재생에너지학회 학술대회논문집 Vol.2009 No.11

Organic by-products derived from cellulose and lignin during organosolv pretreatments of yellow poplar wood (Liriodendron tulipifera) in the presence of H₂SO₄ and NaOH as catalysts, respectively, were subjected to various analyses to elucidate their effects on further performance of biological ethanol fermentation and provide preliminary data for the structure and utilization of organosolv lignin. Monomeric sugars amounted to ca. 2.2-7.7% in the organosoluble fraction of the organosolv pretreatment with H₂SO₄, while significantly low amount of sugars (0.2-0.3%) were determined in that of the organosolv pretreatment with NaOH. In case of addition of H₂SO₄ during organosolv pretreatment of biomass, a fermentation of the organosoluble fraction could be considered as an essential process to increase an efficiency of biomass utilization as well as yield of bioethanol. Precipitates, insoluble by-products in the solvent mixture, were also cficiency oed by diverse analytical methods and revealed that these were typically composed of a lignin moiety regardless of catalyst. According to the results of nuclear magnetic resonance (NMR), Fourier Tcinsform Infrared Spectroscopy (FT-IR) and Gel permeation chromatograp r (GPC), the main components of precipitates seem to be lignin polymers. However, their structures could be slightly modified during pretreatment and mixed with some carbohydrates by chemical bonds and/or physical associations.

Organosolv Pretreatment of Slurry Composting and Biofiltration of Liquid Fertilizer-Treated Yellow Poplar for Sugar Production

Ho Yong Kim,Ki Seob Gwak,Soo Kyeong Jang,Keun Ok Ryu,Hwanmyeong Yeo,In Gyu Choi 한국목재공학회 2015 목재공학 Vol.43 No.5

The present study examines the influence of slurry composting and biofiltration liquid fertilizer (SCBLF) treatment on the biomass characteristics of yellow poplar, and the optimization of organosolv pretreatment for sugar production. After SCBLF treatment, total exchangeable cation contents of yellow poplar was increased from 3.1 g kg-1 to 4.4 g kg-1, and as a result, biomass production of yellow poplar was also enhanced by 82.3%. Organosolv pretreatment was conducted with three independent variables: 1) reaction temperature: 133.2℃ to 166.8℃; 2) acid concentration: 0.2% to 1.8%; and 3) reaction time: 1.6 min to 18.4 min. Reaction temperature was the most significant variable in water insoluble solid (WIS) recovery rate. High overall sugar yield was attained from pretreatment conditions approximately 50% of WIS recovery rate, and the highest overall glucose yield (44.0%) was achieved from pretreatment at 140℃ with 1.5% acid concentration for 5 min. Consequently, 21.1% of glucose and 5.8% of xylose were produced from the organosolv pretreatment of SCBLF-treated 8-year-old yellow poplar.

Biodegradation of PCB congeners by white rot fungus, Ceriporia sp. ZLY-2010, and analysis of metabolites.

Hong, Chang-Young,Gwak, Ki-Seob,Lee, Su-Yeon,Kim, Seon-Hong,Lee, Soo-Min,Kwon, Mi,Choi, In-Gyu Marcel Dekker 2012 Journal of Environmental Science and Health. Part Vol.47 No.12

<P>Polychlorinated biphenyls (PCBs) are difficult to degrade due to poor solubility, toxicity, and thermal stability. In the present study, the feasibility of PCB congener biodegradation by Ceriporia sp. ZLY-2010 was evaluated. The biodegradation rates of four PCB congeners, 4,4'-dichlorobiphenyl, 2,3',4',5-tetrachlorobiphenyl, 2,2',4,5,5'-pentachlorobiphenyl, and 2,2',4,4',5,5'-hexachlorobiphenyl were evaluated. The degradation rate of 4,4'-dichlorobiphenyl was 34.03% on incubation day 13, while that of 2,2',4,4',5,5'-hexachlorobiphenyl reached 40.05% on incubation day 17. Therefore, Ceriporia sp. ZLY-2010 was degrading the higher PCB congeners more efficiently. PCB congener degradation products were extracted using acetone and ethyl acetate. No 2,2',4,5,5'-pentachlorobiphenyl metabolites were detected in Ceriporia sp. ZLY-2010 culture, whereas 2,2',4,4',5,5'-hexachlorobiphenyl appeared to degrade to benzoic acid. However, intermediates of 2,2',4,4',5,5'-hexachlorobiphenyl were not detected during degradation. Therefore, additional studies should be performed to explore the mechanisms of PCB degradation. Our results indicate that Ceriporia sp. ZLY-2010 is able to degrade highly chlorinated biphenyls and has potential for use in PCB biodegradation and bioremediation.</P>

Antifungal Activities of the Essential Oils in Syzygium aromaticum (L.) Merr. Et Perry and Leptospermum petersonii Bailey and their Constituents against Various Dermatophytes

Mi-Jin Park,Ki-Seob Gwak,양인,Won-Sil Choi,Hyun-Jin Jo,Je-Won Chang,정의배,최인규 한국미생물학회 2007 The journal of microbiology Vol.45 No.5

This study was carried out in order to investigate the potential of using plant oils derived from Leptospermum petersonii Bailey and Syzygium aromaticum L. Merr. Et Perry as natural antifungal agents. The antifungal effects of essential oils at concentrations of 0.05, 0.1, 0.15, and 0.2 mg/ml on the dermatophytes Microsporum canis (KCTC 6591), Trichophyton mentagrophytes (KCTC 6077), Trichophyton rubrum (KCCM 60443), Epidermophyton floccosum (KCCM 11667), and Microsporum gypseum were evaluated using the agar diffusion method. The major constituents of the active fraction against the dermatophytes were identified by gas chromatography-mass spectrometry and high performance liquid chromatography analysis. The antifungal activities of S. aromaticum oil (clove oil) against the dermatophytes tested were highest at a concentration of 0.2 mg/ml, with an effectiveness of more than 60%. Hyphal growth was completely inhibited in T. mentagrophytes, T. rubrum, and M. gypseum by treatment with clove oil at a concentration of 0.2 mg/ml. Eugenol was the most effective antifungal constituent of clove oil against the dermatophytes T. mentagrophytes and M. canis. Morphological changes in the hyphae of T. mentagrophytes, such as damage to the cell wall and cell membrane and the expansion of the endoplasmic reticulum, after treatment with 0.11 mg/ml eugenol were observed by transmission electron microscopy (TEM). At a concentration of 0.2 mg/ml, L. petersonii oil (LPO) was more than 90% effective against all of the dermatophytes tested, with the exception of T. rubrum. Geranial was determined to be the most active antifungal constituent of L. petersonii oil. Taken together, the results of this study demonstrate that clove and tea tree oils exhibited significant antifungal activities against the dermatophytes tested in this study. This study was carried out in order to investigate the potential of using plant oils derived from Leptospermum petersonii Bailey and Syzygium aromaticum L. Merr. Et Perry as natural antifungal agents. The antifungal effects of essential oils at concentrations of 0.05, 0.1, 0.15, and 0.2 mg/ml on the dermatophytes Microsporum canis (KCTC 6591), Trichophyton mentagrophytes (KCTC 6077), Trichophyton rubrum (KCCM 60443), Epidermophyton floccosum (KCCM 11667), and Microsporum gypseum were evaluated using the agar diffusion method. The major constituents of the active fraction against the dermatophytes were identified by gas chromatography-mass spectrometry and high performance liquid chromatography analysis. The antifungal activities of S. aromaticum oil (clove oil) against the dermatophytes tested were highest at a concentration of 0.2 mg/ml, with an effectiveness of more than 60%. Hyphal growth was completely inhibited in T. mentagrophytes, T. rubrum, and M. gypseum by treatment with clove oil at a concentration of 0.2 mg/ml. Eugenol was the most effective antifungal constituent of clove oil against the dermatophytes T. mentagrophytes and M. canis. Morphological changes in the hyphae of T. mentagrophytes, such as damage to the cell wall and cell membrane and the expansion of the endoplasmic reticulum, after treatment with 0.11 mg/ml eugenol were observed by transmission electron microscopy (TEM). At a concentration of 0.2 mg/ml, L. petersonii oil (LPO) was more than 90% effective against all of the dermatophytes tested, with the exception of T. rubrum. Geranial was determined to be the most active antifungal constituent of L. petersonii oil. Taken together, the results of this study demonstrate that clove and tea tree oils exhibited significant antifungal activities against the dermatophytes tested in this study.

Biological Pretreatment of Softwood Pinus densiflora by Three White Rot Fungi

Lee, Jae-Won,Gwak, Ki-Seob,Park, Jun-Yeong,Park, Mi-Jin,Choi, Don-Ha,Kwon, Mi,Choi, In-Gyu The Microbiological Society of Korea 2007 The journal of microbiology Vol.45 No.6

The effects of biological pretreatment on the Japanese red pine Pinus densiflora, was evaluated after exposure to three white rot fungi Ceriporia lacerata, Stereum hirsutum, and Polyporus brumalis. Change in chemical composition, structural modification, and their susceptibility to enzymatic saccharification in the degraded wood were analyzed. Of the three white rot fungi tested, S. hirsutum selectively degraded the lignin of this sortwood rather than the holocellulose component. After eight weeks of pretreatment with S. hirsutum, total weight loss was 10.7%, while lignin loss was the highest at 14.52% among the tested samples. However, holocellulose loss was lower at 7.81 % compared to those of C. lacerata and P. brumalis. Extracelluar enzymes from S. hirsutum showed higher activity of ligninase and lower activity of cellulase than those from other white rot fungi. Thus, total weight loss and changes in chemical composition of the Japanese red pine was well correlated with the enzyme activities related with lignin- and cellulose degradation in these fungi. Based on the data obtained from analysis of physical characterization of degraded wood by X-ray Diffractometry (XRD) and pore size distribution, S. hirsutum was considered as an effective potential fungus for biological pretreatment. In particular, the increase of available pore size of over 120 nm in pretreated wood powder with S. hirsutum made enzymes accessible for further enzymatic saccharification. When Japanese red pine chips treated with S. hirsutum were enzymatically saccharified using commercial enzymes (Cellulclast 1.5 L and Novozyme 188), sugar yield was greatly increased (21.01 %) compared to non-pre treated control samples, indicating that white rot fungus S. hirsutum provides an effective process in increasing sugar yield from woody biomass.