• 공업화학
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• 제27권2호
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• pp.135-144
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• 2016

불안정한 원유 가격과 지속적인 환경 문제를 야기하고 있는 석유 자원의 대체를 위한 바이오매스 활용 기술 개발과 상업화가 활발히 진행되고 있다. 목질계 바이오매스 전처리와 펄프 제조 과정에서 다량으로 발생하는 리그닌은 바이오에탄올 제조량의 증가와 더불어 발생량 또한 급속히 증가할 것으로 예상되고 있다. 리그닌은 방향족 고분자로 hydroxyl기와 같은 화학 작용기를 갖고 있어 화학 소재 원료로서의 활용이 가능한 저가 부산물이다. 리그닌의 방향족구조와 작용기를 oxypropylation, epxoidation 등을 이용하여 화학적으로 변환시켜 반응성을 향상시키거나, 새로운 화학작용기를 도입함으로써 바이오폴리우레탄, 바이오폴리에스터, 페놀 수지, 에폭시 수지 등 바이오플라스틱 제조에 활용이 가능하다. 본 총설은 리그닌을 활용하여 제조 가능한 바이오플라스틱, 수지, 탄소섬유 등에 대해 소개하고, 관련 최신 연구 동향 및 리그닌 응용 기술에 관한 전망을 소개하였다.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2009년도 춘계학술발표회 논문집
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• pp.109-110
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• 2009

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 추계학술대회
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• pp.529-532
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• 2006

Recently the production of ethanol from lignocecllulosics has received much attention due to immense potential for conversion of renewable biometerials into biofuels and chemicals. Fomitopsis palustris causes a typycal brown-rot and is unusual in that it rapidly depolymerize the cellulose in wood without removing the surrounding lignin that normally prevents microbial attack. This study demonstrated that the brown rot basidiomycete F. palustris was able to degrade crystalline cellulose. This fungus could also produce the three major cellulases (BGL, EXG and EG) when the cells were grown on 2.0% Avicel. The fungus was able to degrade both the crystalline and amorphous forms of cellulose from woody biomasses. Moreover, we found that this fungus has the processive EG like CBH which are able to degrade the crystalline region of cellulose. To establish the cellulase system in relation with degradation of woody biomass, we performed that purification, characterization and molecular cloning of a BGL, EGs and GLA from F. palustris grown on Avicel.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVII)
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• pp.94-94
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• 2005

• Journal of Microbiology and Biotechnology
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• 제26권9호
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• pp.1557-1565
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• 2016

Itaconic acid (IA) is a dicarboxylic acid included in the US Department of Energy's (DOE) 2004 list of the most promising chemical platforms derived from sugars. IA is produced industrially using liquid-state fermentation (LSF) by Aspergillus terreus with glucose as the carbon source. To utilize IA production in renewable resource-based biorefinery, the present study investigated the use of lignocellulosic biomass as a carbon source for LSF. We also investigated the production of fumaric acid (FA), which is also on the DOE's list. FA is a primary metabolite, whereas IA is a secondary metabolite and requires the enzyme cis-aconitate decarboxylase for its production. Two lignocellulosic biomasses (wheat bran and corn cobs) were tested for fungal fermentation. Liquid hydrolysates obtained after acid or enzymatic treatment were used in LSF. We show that each treatment resulted in different concentrations of sugars, metals, or inhibitors. Furthermore, different acid yields (IA and FA) were obtained depending on which of the four Aspergillus strains tested were employed. The maximum FA yield was obtained when A. terreus was used for LSF of corn cob hydrolysate (1.9% total glucose); whereas an IA yield of 0.14% was obtained by LSF of corn cob hydrolysates by A. oryzae.

• Plant Biotechnology Reports
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• 제5권1호
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• pp.1-7
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• 2011

Secondary walls have recently drawn research interest as a primary source of sugars for liquid biofuel production. Secondary walls are composed of a complex mixture of the structural polymers cellulose, hemicellulose, and lignin. A matrix of hemicellulose and lignin surrounds the cellulose component of the plant's cell wall in order to protect the cell from enzymatic attacks. Such resistance, along with the variability seen in the proportions of the major components of the mixture, presents process design and operating challenges to the bioconversion of lignocellulosic biomass to fuel. Expanding bioenergy production to the commercial scale will require a significant improvement in the growth of feedstock as well as in its quality. Plant biotechnology offers an efficient means to create "targeted" changes in the chemical and physical properties of the resulting biomass through pathway-specific manipulation of metabolisms. The successful use of the genetic engineering approach largely depends on the development of two enabling tools: (1) the discovery of regulatory genes involved in key pathways that determine the quantity and quality of the biomass, and (2) utility promoters that can drive the expression of the introduced genes in a highly controlled manner spatially and/or temporally. In this review, we summarize the current understanding of the transcriptional regulatory network that controls secondary wall biosynthesis and discuss experimental approaches to developing-xylem-specific utility promoters.

• Mass Spectrometry Letters
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• 제4권1호
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• pp.1-9
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• 2013

Fungal biotechnology has been well established in food and healthcare sector, and now being explored for lignocellulosic biorefinery due to their great potential to produce a wide array of extracellular enzymes for nutrient recycling. Due to global warming, environmental pollution, green house gases emission and depleting fossil fuel, fungal enzymes for lignocellulosic biomass refinery become a major focus for utilizing renewal bioresources. Proteomic technologies tender better biological understanding and exposition of cellular mechanism of cell or microbes under particular physiological condition and are very useful in characterizing fungal secretome. Hence, in addition to traditional colorimetric enzyme assay, mass-spectrometry-based quantification methods for profiling lignocellulolytic enzymes have gained increasing popularity over the past five years. Majority of these methods include two dimensional gel electrophoresis coupled to mass spectrometry, differential stable isotope labeling and label free quantitation. Therefore, in this review, we reviewed more commonly used different proteomic techniques for profiling fungal secretome with a major focus on two dimensional gel electrophoresis, liquid chromatography-based quantitative mass spectrometry for global protein identification and quantification. We also discussed weaknesses and strengths of these methodologies for comprehensive identification and quantification of extracellular proteome.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 추계학술대회 논문집
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• pp.511-511
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• 2009

Lignocellulosic biomass is the most abundant organic material on earth and also promising raw material for bioenergy production. Agricultural residues in the process of bio-oil extraction, is an abundant and low-cost lignocellulosic material. The technology for conversion of lignocellulosic biomass resources to fuels and chemicals, such as ethanol, has been under development for decades. One of the well-studied technologies that are currently being commercialized is to use a dilute acid-catalyzed pretreatment followed by enzymatic hydrolysis and fermentation to produce ethanol. In this work, the dilute-acid hydrolysis of agricultural residues was optimized through the utilization of statistical experimental design. Evaluation criteria for optimization of the pretreatment conditions were based on high xylose recovery and low inhibitor contents in the hydrolyzates. The purpose of this study was to gain a more accurate understanding of the quantities of acid required for effective hydrolysis and the reactivity trade-offs with reaction time and temperature that will enable overall process optimization.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 추계학술대회 논문집
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• pp.71-73
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• 2008

Different biosolid fuel (wood pellet) properties between trunk and root of pine (Pinus densiflora) biomass were investigated. Trunk has more organic solvent extracts and Klason lignin content which has higher heating values than root biomass component. In root biomass, polysaccharides content was higher than trunk biomass. Based on Higher Heating Value (HHD) analysis and ash content, trunk biomass showed better solid fuel characteristics than root biomass. But pine root biomass had lower HHD than trunk biomass, its HHD values were higher than other hardwood or annual plant lignocellulosic biomass.

• Korean Chemical Engineering Research
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• 제49권3호
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• pp.292-296
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• 2011

섬유소계 바이오매스의 전처리를 위한 암모니아수에 의한 침지공정(SAA; Soaking in Aqueous Ammonia)은 낮은 온도와 낮은 압력의 조건에서 수행하는 전처리 공정으로 고온고압이 필요로 하는 다른 전처리방법에 비해 그에 대한 비용을 절감할 수 있다는 장점이 있다. 본 연구에서는 다양한 바이오매스를 SAA공정에 적용시켜 그 특성을 보고자 한다. 실험을 행한 전처리 공정의 온도, 반응시간 그리고 암모니아수의 농도는 각각 $50{^{\circ}C}$, 72시간 그리고 15 wt%이다. 전처리 공정에 의해 초본계열은 탈리그닌이 초기 성분에 대해 60%로 되었고 전처리 전의 10-20%에 불과하던 당전환율이 전처리 후에 60-90%의 당전환율로 약 80%가 향상된 것으로 나타났지만 목본계열의 리그닌 성분은 10%정도만 제거되었고 당전환율은 전처리하지 않는 것과 별다른 차이를 보이지 않았다.