White rot fungus Cerrena unicolor IUM 5400 produced ethanol from diverse sugars, including glucose, mannose, galactose, and cellobiose at 0.38, 0.28, 0.08, and 0.27 g of ethanol per g of sugar consumed, respectively. The fungus produced relatively high amounts of ethanol from xylose (0.28 g of ethanol per g of sugar consumed); however, the ethanol conversion rate of arabinose was relatively low (at 0.08 g of ethanol per g sugar consumed). When cultured in a basal medium containing 20 g/L rice straw or corn stalks, C. unicolor IUM 5400 produced 0.18 g and 0.18 g of ethanol per g of rice straw and corn stalks, respectively. The results suggest that C. unicolor IUM 5400 is a white rot fungus that can effectively hydrolyze cellulose or hemicellulose to sugars and simultaneously convert them to ethanol.

Lignocellulosic biomass conversion to biofuels such as ethanol and other value-added bio-products including activated carbons has attracted much attention. The development of an efficient, cost-effective, and eco-friendly pretreatment process is a major challenge in lignocellulosic biomass to biofuel conversion. Although several modern pretreatment technologies have been introduced, few promising technologies have been reported. Microwave irradiation or microwave-assisted methods (physical and chemical) for pretreatment (disintegration) of biomass have been gaining popularity over the last few years owing to their high heating efficiency, lower energy requirements, and easy operation. Acid and alkali pretreatments assisted by microwave heating meanwhile have been widely used for different types of lignocellulosic biomass conversion. Additional advantages of microwave-based pretreatments include faster treatment time, selective processing, instantaneous control, and acceleration of the reaction rate. The present review provides insights into the current research and advantages of using microwave-assisted pretreatment technologies for the conversion of lignocellulosic biomass to fermentable sugars in the process of cellulosic ethanol production.

In the present study, lab-scale fast pyrolysis reactor (1kg/hr) using lignocellulosic waste biomass was numerically modeledwith various reaction mechanism and the calculation results were compared. Three kinds of reaction mechanisms were appliedsuch as three-step mechanism, two-stage, semi global mechanism and Broido-Shafizadeh mechanism to simulate chemicalreactions in the fast pyrolysis reactor. The fast pyrolysis reactor was modeled as function of mass fraction and reactiontemperature following each reaction mechanism. Especially, the reaction temperature is one of important factors to determinebio-oil yield. Hence, in this study, reaction rates and yield of fast pyrolysis products were compared with varying reactiontemperature for the three kinds of reaction mechanism. The variation of reaction rate for two-stage, semi global mechanismand Broido-Shafizadeh mechanism showed very similar pattern but, three-step mechanism has different trend because theeffect of secondary reaction was missing. The yield of tar was increased before reaching maximum tar yield at 430oC and520oC for two-stage, semi global mechanism and Broido-Shafizadeh mechanism, respectively then decreased as temperaturerises more. But, the yield of tar was increased continuously for three-step mechanism as temperature rises. The yield of non-condensable gas and char was increased as temperature rises for three kinds of reaction mechanisms.

농업유래의 바이오매스 중 볏짚의 저장형태와 저장기간에 따른 수분함량 변화와 바이오매스의 화학적 성분 변화를분석함으로써 바이오에탄올 생산을 위한 원료의 최적 저장방법을 제시하고자 하였다. 주요 결과는 아래와 같다.1. 볏짚의 수분함량 변이를 측정한 결과 실내에서 보관한사각곤포 및 원형곤포는 약 20 ~ 25%의 수분함량을유지하였으며 실외에서 보관한 비가림 시설을 도입한사각곤포의 경우 20%이하의 낮은 수분함량을 확인하였다.2. 볏짚의 화학적 성분의 변이를 분석한 결과 실외보관곤포는 cellulose 및 hemicellulose의 함량이 큰 폭으로감소하였으나, 실내에서 보관한 곤포들은 비닐원형곤포를 제외한 나머지 집속형태에서는 오히려 성분의 함량의 증가를 확인하였다.3. 볏짚을 장기간 보관할 때에는 외부환경을 차단할 수있는 실내에서 보관하거나 부득이하게 실외에서 보관할 때 최소 비가림 시설을 도입하여 수분함량 및 화학적 성분의 감소를 최소화해야 바이오에탄올 생산을 위한 고품질의 원료로써 이용될 수 있을 것이다.

Sugarcane is one of the most efficient photosynthesizer in the plant kingdom, able to convert as much as 2% of incident solar energy into biomass. A large amount of lignocellulosic biomass such as leaf litter residues and bagasse are generated during the sugarcane harvest or after the sugar refining process, respectively. Therefore, lignocellulosic biomass from leaf and processing residues will likely become a valuable feedstock for biofuel production. However, higher temperatures and/or acid concentrations result in dehydration of xylose to furfural, and glucose to hydroxymethyl furfural, which act as inhibitors of the fermentation process. New pretreatment protocols are being developed that require the application of xylanases and other enzymes for maximal yields of xylose. Our objectives target the improvement of fermentable sugar yields from hemicellulosic sugarcane residues and enhancing the biosafety of the transgenic plants. We evaluated two transgenic approaches: lignin modification by RNAi suppression of the lignin biosynthetic gene COMT and in planta production of a hyperthermostable xylanase. More than 200 transgenic sugarcane plants were generated and lines with suppression or expression of the target genes were selected. RNAi suppression of COMT resulted in reduced lignin content and altered lignin composition. In planta produced xylanase Xyl10B converted the majority of sugarcane xylan to fermentable xylobiose. Performance and conversion efficiency of transgenic plants grown in replicated field plots under USDA-Aphis notification 11-040-120 will also be presented.