목질계 셀룰로오스 에탄올 생산공정에서 전처리과정의 설계

김형진 ( Hyungjin Kim ),이승범 ( Seung Bum Lee ) 한국공업화학회 2015 공업화학 Vol.26 No.4

A pretreatment process of cellulose decomposition to a monosaccharide plays an important role in the cellulosic ethanol production using the lignocellulosic biomass. In this study, a cellulosic ethanol was produced by using acidic hydrolysis and enzymatic saccharification process from the lignocellulosic biomass such as rice straw, sawdust, copying paper and newspaper. Three different pretreatment processes were compared; the acidic hydrolysis (100 ℃, 1 h) using 10~30 wt% of sulfuric acid, the enzymatic saccharification (30 min) using celluclast (55 ℃, pH = 5.0), AMG (60 ℃, pH = 4.5), and spirizyme (60 ℃, pH = 4.2) and also the hybrid process (enzymatic saccharification after acidic hydrolysis). The yield of cellulosic ethanol conversion with those pretreatment processes were obtained as the following order : hybrid process > acidic hydrolysis > enzymatic saccharification. The optimum fermentation time was proven to be two days in this work. The yield of cellulosic ethanol conversion using celluclast after the acidic hydrolysis with 20 wt% sulfuric acid were obtained as the following order : sawdust > rice straw > copying paper > newspaper when conducting enzymatic saccharification.

Effect of [EMIM]Ac amount remained in the pretreated lignocellulose on enzymatic saccharification

( Songyi Han ),( Chanwoo Park ),( Hyunwoo Namgung ),( Pureunnarae Seo ),( Seunghwan Lee ) 韓國木材工學會 2016 한국목재공학회 학술발표논문집 Vol.2016 No.2

The pretreatment to open up or disrupt the cell wall structure of lignocellulosic biomass is an essential process to improve the enzymatic saccharification. Ionic liquids have been used as new green solvents for the pretreatment of lignocellulosic biomass to improve enzymatic saccharification. l-Eethyl-3-methyl imidazolium acetate ([EMIM]Ac) is one of the best ionic liquids for the enzymatic saccharification of lignocellulosic biomass. However, [EMIM]Ac is known to inhibit the activity of enzyme and difficult to be completely removed from the pretreated product. Thus, this study evaluated the effect of the [EMIM]Ac amount remained in the pretreated lignocellulose on enzymatic saccharification by adjusting its amount during washing process with distilled water after pretreatment. The pussy willow (Salix gracilistyla Miq.) was used as lignocellulosic biomass and enzyme was performed using enzyme cocktail with acremonium-derived enzyme (Meiji Seika Co., Tokyo, Japan) and optimash BG (Genencor, Rochester, New york, USA) at 45℃ for 72 hours using shaking incubator.

Pretreatment of lignocellulose using recycled ionic liquid for enzymatic saccharification

( Songyi Han ),( Soyeon Kim ),( Seonngmin Ji ),( Chanwoo Park ),( Hyunwoo Namgung ),( Pureunnarae Seo ),( Seunghwan Lee ) 韓國木材工學會 2016 한국목재공학회 학술발표논문집 Vol.2016 No.2

Ionic liquids is known to have many merits in view of green chemistry, such as high thermal stability, non-volatility, non-flammability, low melting points, excellent dissolution ability compared with volatile organic solvents. With these advantages, ionic liquids have been used as new green solvents in various biorefinery research fields, especially for the pretreatment of lignocellulosic biomass to improve enzymatic saccharification. Especially, 1-ethyl-3-methyl imidazolium acetate ([EMIM]Ac) has been known to be effective for the dissolution of total lignocellulose components. However, ionic liquids are generally more expensive than other organic solvents, which remains a problem to be solved. This study was carried out to investigate how may times [EMIM]Ac) can be reused for the pretreatment, not losing its effectiveness.

꼬시래기 홍조류로부터 열산가수분해, 효소당화 및 에탄올 발효

나채훈 ( Chae Hun Ra ),최진규 ( Jin Gyu Choi ),강창한 ( Chang Han Kang ),선우인영 ( In Yung Sun Woo ),정귀택 ( Gwi Taek Jeong ),김성구 ( Sung Koo Kim ) 한국미생물생명공학회(구 한국산업미생물학회) 2015 한국미생물·생명공학회지 Vol.43 No.1

본 연구는 해조류, 꼬시래기를 발효하여 에탄올을 생산하였다. 최적 전처리 조건은 12% (w/v) 해조류 슬러리, 270 mM 황산, 121도60분동안 실시하였다. 열산가수분해 후에, 꼬시래기 가수분해산물에 16 U/ml의 혼합효소 Viscozyme L과 Celluclast 1.5 L를 이용하여 효소당화를 수행하였다. 50.4 g/l의 총 단당류의 농도는, 120 g dw/l 꼬시래기 슬러리로부터 열산가수분해와 효소당화에 의해 총 탄수화물 60 g/l의 전환율 84.2%를 나타내었다. 꼬시래기 가수분해산물은 분리당화발효(SHF)로 에탄올 생산을 위한 기질로 사용하였다. 고농도 galactose로 순치한 Candida lusitaniae ATCC42720에 의한 에탄올 생산은 0.43의 에탄올 수율(YEtOH)인 22.0 g/l를 생산하였다. 특정 당에 순치한 효모는 혼합당의 흡수에 유용하며, 그 결과 해조류 가수분해산물 배지로부터 높은 에탄올 수율을 나타내었다. The seaweed, Gracilaria verrucosa, was fermented to produce bioethanol. Optimal pretreatment conditions were determined to be 12% (w/v) seaweed slurry and 270 mM sulfuric acid at 121oC for 60 min. After thermal acid hydrolysis, enzymatic saccharification was carried out with 16 U/ml of mixed enzymes using Viscozyme L and Celluclast 1.5 L to G. verrucosa hydrolysates. A total monosaccharide concentration of 50.4 g/l, representing 84.2% conversion of 60 g/l total carbohydrate from 120 g dw/l G. verrucosa slurry was obtained by thermal acid hydrolysis and enzymatic saccharification. G. verrucosa hydrolysate was used as the substrate for ethanol production by separate hydrolysis and fermentation (SHF). Ethanol production by Candida lusitaniae ATCC 42720 acclimated to high-galactose concentrations was 22.0 g/l with ethanol yield (YEtOH) of 0.43. Acclimated yeast to high concentrations of specific sugar could utilize mixed sugars, resulting in higher ethanol yields in the seaweed hydrolysates medium.

Optimization of sugar extraction from sewage sludge after lipid extraction by dilute-acid pretreatment and enzymatic saccharification, and bioethanol production using these sugars

( Supaporn Pansuwan ),염승호 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.0

Sewage sludge after lipid extraction for biodiesel production was used to obtain sugars for bioethanol production. The extraction of sugars was carried out by dilute-acid pretreatment, followed by enzymatic saccharification. The optimal pretreatment conditions were optimized through response surface methodology, and these were 120 °C, 85 min and acid concentration of 5.9%(v/v). Under these conditions, sugar yield was 75.5%. Enzyme mixtures (celluclast: viscozyme) at the total volume and ratio of 1:2 showed the highest sugar yield (31.4%). Consequently, more than 90% of sugar was extracted from the sewage sludge. Finally, commercial yeasts from six manufacturers were evaluated for bioethanol production, and the optimum microorganism successfully produced bioethanol using the sugars from sewage sludge.

Organosolv 전처리를 통한 리기다소나무의 바이오에탄올 생산 적용성 평가

유원재(Won-Jae Youe),김용식(Yong Sik Kim),강규영(Kyu-Young Kang) 한국펄프·종이공학회 2015 펄프.종이기술 Vol.47 No.4

In this study, the feasibility of utilizing wood chips from pitch pine (Pinus rigida) was evaluated for bioethanol production by an organosolv pretreatment and enzymatic saccharification. When wood chips from pitch wood were pretreated with 75% (v/v) ethanol and 1.7% sulfuric acid as a catalyst at H-factor 2000, average pulp yield was 43.3%, which pretreated wood fibers showed higher glucan (55.8%) and lower lignin (12.2%) contents than untreated control (43.9% glucan and 27.8% lignin). After enzymatic saccharification, the organosolv pulps with 56.2% delignification rate reached above 97% conversion rate of cellulose to glucose. These results indicated that increasing the delignification rate causes micro pores on the surface of organosolv pulps resulting in improved the accessibility of enzyme onto the substrate. Moreover, it was in agreement with the SEM examination of wood fibers.

An integrative process for obtaining lipids and glucose from <i>Chlorella vulgaris</i> biomass with a single treatment of cell disruption

Heo, Young Mok,Lee, Hanbyul,Lee, Changsu,Kang, Juwon,Ahn, Joon-Woo,Lee, Young Min,Kang, Kyu-Young,Choi, Yoon-E,Kim, Jae-Jin Elsevier 2017 Algal research Vol.27 No.-

<P><B>Abstract</B></P> <P>To examine the possibility of better utilizing <I>Chlorella vulgaris</I> biomass including its carbohydrate as well as lipid contents, it was investigated whether cell disruption for lipid extraction could render the remaining microalgal residue (MR) suitable for enzymatic saccharification, possibly due to the disruption of cell wall structures. The <I>C. vulgaris</I> biomass was subjected to lipid extraction with different cell disruption methods (autoclaving, microwave irradiation, osmotic shock, and sonication), and recovered MRs were hydrolyzed using an enzyme produced from <I>Trichoderma koningiopsis</I> KUC21269 in this study. The enzyme was produced on-site with a highly simplified medium of barley straw, an agricultural byproduct. As a result, the saccharification rate of MR treated with microwave was more than twice that of the control group, and microwave irradiation appeared to be a promising method for both lipid extraction and subsequent saccharification. Our results suggested that both lipids and carbohydrates in <I>C. vulgaris</I> can be utilized by applying proper cell disruption method and a fungal enzyme produced on-site using an agricultural byproduct, respectively. This study revealed the high potential of <I>C. vulgaris</I> as an integrated bio-resource for both lipids and glucose, which can be converted to biodiesel and bioethanol, providing clues for overcoming hurdles in economically feasible biofuel production using microalgae.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Both lipids and glucose in <I>C. vulgaris</I> could be obtained with a single treatment. </LI> <LI> Cell disruption for lipid extraction could also damage cell wall structures. </LI> <LI> Lipid-extracted residues were hydrolyzed using a fungal enzyme produced on-site. </LI> <LI> Saccharification rate was more than doubled by microwave irradiation. </LI> <LI> Microwave irradiation enhanced the bioaccessibility of cellulose in the cell walls. </LI> </UL> </P>

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.

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.

Optimization of Pretreatment Conditions and Use of a Two-stage Fermentation Process for the Production of Ethanol from Seaweed, Saccharina japonica

Chae Hun Ra,김성구 한국생물공학회 2013 Biotechnology and Bioprocess Engineering Vol.18 No.4

Saccharina japonica (Sea tangle, Dasima), a seaweed, was fermented in order to produce bioethanol after thermal hydrogen peroxide (H2O2) hydrolysis pretreatment and enzymatic saccharification. The optimal pretreatment conditions of 1% (v/v) H2O2 (28%, Dustan Pure Chemicals Co., Ltd, Ansan, Korea) and 10% (w/v) seaweed slurry at 121oC for 60 min were determined using the Response Surface Method (RSM). A reducing sugar yield of 33.4%(w/w) and a viscosity of 520 cP were obtained. Enzymatic saccharification was then carried out; a monosaccharide concentration of 28.5 g/L with a 40.5% (w/w) theoretical yield was obtained after the addition of 2-mL Celluclast®1.5L to 100 g/L of seaweed slurry after thermal H2O2hydrolysis. Fermentation of a two-stage ethanol production was carried out using Saccharomyces cerevisiae KCCM 1129 in order to ferment glucose in the first stage, and a high level of mannitol-acclimated Pichia angophorae KCTC 17574 to ferment mannitol in the second stage. Acclimation of yeast effectively slowed the uptake of sugar in ethanol fermentation. The overall ethanol yield from S. japonica after the two-stage fermentation was 9.9 g/L.