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The eutrophication of lake and followed cyanobacteria bloom are the most apparently eco-environmental problem in freshwater lakes in China. Lake Dianchi is the largest and the most serious eutrophic freshwater lake in southwest China that has experienced cyanobacterial blooms annually during the last few decades. The temporal distribution of phytoplankton biomass (estimated using chlorophyll-a concentration) and its correlation with related physical and chemical viriables including water temperature, pH, total phosphorus(TP) and total nitrogen(TN) in Lake Dianchi were investigated from March 2009 to January 2010. Due to the combined effects of high temperature, nutrient conditions and neutral to alkaline pH values in this lake, the phytoplankton biomass were higher and more uniform compared to other cyanobacterial blooms reported in temperate regions. This study advances our understanding of nutrient enrichment and high water temperature influences on phytoplankton biomass.

In this work, total heavy metals (Cd, Cu, Pb and Zn) concentrations and corresponding speciation extraction of the certified reference material (soil GBW07445) were analyzed by flame atomic absorption spectrometry (FAAS) with microwave-assisted digestion (MAD) and microwave-assisted extraction (MAE). The experiments were optimized to improve efficiencies with smaller amount of reagents in less time. The interactions between variables such as holding time and temperature were investigated with central composite designs (CCDs). In the total content determination, the relative errors were 9.38%, 5.38%, 2.83% 1.95% for Cd, Cu, Pb and Zn, respectively and the relative errors of Cd, Cu, Pb and Zn in each extraction procedure were in the range of 5.88%-16.7%, 0%-12.5%, 1.24%-12.5% and 1.18%-11.0%, respectively. The relative standard deviations (RSD, n=3) were all below 10%. The results of sample analysis were also stated. All the experiments illustrated that the proposed methods were suitable for heavy metal analysis in soils.

Phenolic endocrine disrupting compounds, including nonylphenol-di-ethoxylate (NP2EO), nonylphenol-mono-ethoxylate (NP1EO), 4-nonylphenol (4-NP), bisphenol A (BPA), 4-cumylphenol (4-CP) and 4-tert-octylphenol (4-t-OP), were investigated in water, surface sediment and sediment cores in Dianchi Lake to track their seasonal distributions, pollution sources and historical trends. The concentrations of NP2EO, NP1EO, 4-NP, BPA, 4-CP and 4-t-OP were up to 295.14, 448.48, 45.28, 530.33, 8.96 and 21.37 ng L(-1) in water, and up to 297.11, 809.63, 4.58, 166.87, 3.62 and 40.69 ng g(-1) dry weight in surface sediment, respectively. Except BPA in water, concentrations of all the other phenolic compounds in both of the matrices were higher in January than in July, 2011. The concentrations decreased significantly with an increase in distance from the sampling locations which were adjacent to the urban areas (Kunming City, Chenggong City and Jinning City). The pollution of phenolic EDCs came mainly from industry, agriculture and daily life. The relationships between the concentrations of target compounds and the six water quality parameters were evaluated. There were significant positive correlations between concentrations of phenolic compounds in water and in surface sediment. For sediment cores, three clearly separated maxima occurred in segments 0-5 cm (the late 2000s), 5-10 cm (the early and mid of 2000s) and 20-25 cm (the mid of 1980s), respectively. NP2EO, NP1EO and BPA were the three dominant compounds in the lake.

Dianchi Lake is one of the three most seriously eutrophic lakes in China. In the present study, the nitrogen fractions and vertical profiles of various nitrogen forms in 11 sediment cores sampled in the Dianchi Lake were investigated. The results showed that the total nitrogen content ranged from 1596.60 to 3238.68 mg/kg, and the contribution to total nitrogen of transferrable nitrogen and fixed nitrogen is close. The vertical profiles of total nitrogen were coincidence in the pollution history of Dianchi Lake.

The plasticity of lignin biosynthesis should permit the inclusion of new compatible phenolic monomers, such as rosmarinic acid (RA) and analogous catechol derivatives, into cell-wall lignins that are consequently less recalcitrant to biomass processing. In vitro lignin polymerization experiments revealed that RA readily underwent peroxidase-catalyzed copolymerization with monolignols and lignin oligomers to form polymers with new benzodioxane inter-unit linkages. Incorporation of RA permitted extensive depolymerization of synthetic lignins by mild alkaline hydrolysis, presumably by cleavage of ester intra-unit linkages within RA. Copolymerization of RA with monolignols into maize cell walls by in situ peroxidases significantly enhanced alkaline lignin extractability and promoted subsequent cell wall saccharification by fungal enzymes. Incorporating RA also improved cell wall saccharification by fungal enzymes and by rumen microflora even without alkaline pretreatments, possibly by modulating lignin hydrophobicity and/or limiting cell wall cross-linking. Consequently, we anticipate that bioengineering approaches for partial monolignol substitution with RA and analogous plant hydroxycinnamates would permit more efficient utilization of plant fiber for biofuels or livestock production.

Endocrine disrupting chemicals (EDCs) found in wastewater treatment plant (WWTP) effluents have been shown to cause adverse effects, but the uptake of EDCs from effluents (measured in fish muscle) are not known. In this study, the biological effects and bioaccumulation of steroidal and phenolic EDCs were assessed in high-back crucian carp (Carassius auratus) exposed to WWTP effluents for 141 days. Compared with fish controls caged in Dianchi Lake, a significant reduction in gonadosomatic index (GSI) and increase in hepatosomatic index (HSI) and plasma vitellogenin (VTG) levels were observed in effluent-exposed fish. The concentrations of steroids and phenols in effluent-exposed fish showed time-dependent increase during the exposure. In addition, bioconcentration factors (BCFs) for steroids and phenols were between 17 and 59 on day 141. The results confirm that steroids and phenols bioconcentrate in fish muscle and this accumulation may account for the biological effects associated with exposures to WWTP effluents.

Dianchi Lake, one of the most eutrophication freshwater lakes in china, has been under severely eutrophic condition since 1970s. This study investigated the concentrations of total phosphorus (TP), soluble reactive phosphorus (SRP) in the overlying water and the interstitial water in water-sediment interface through analysis of the water samples collected from 37 sites around Dianchi Lake to obtain further understanding of recent characteristics of phosphorus pollution, and to estimate the dominant potential phosphorus sources in varied lake regions. Results showed that the mean TP and SRP contents were 0.271mg/L, 0.039mg/L in Waihai and 0.356mg/L, 0.159mg/L in Caohai from the overlying water, compared with 0.395mg/L, 0.010mg/L in Waihai and 1.229mg/L and 0.790mg/L in Caohai from the interstitial water, respectively. It was revealed that the internal phosphorus source has been the dominant phosphorus pollution sources occurred in prolonged pollutant accumulation and hyper-eutrophication Caohai section, the external and internal phosphorus sources coexist in wide open Waihai section.

Preface Feedstock, Availability, Production, and Harvesting 1. Forest Biomass Sustainability and Availability K. E. Skog and J. A. Stanturf 2. Woody Biomass from Short Rotation Energy Crops R. S. Zalesny, Jr., M. W. Cunningham, R. B. Hall, J. Mirck, D. L. Rockwood, J. A. Stanturf, and T. A. Volk 3. Biomass Logistics - Harvest and Storage Kevin J. Shinners, Matthew F. Digman, and Troy M. Runge Woody Biomass Deconstruction 4. Physical Pretreatment ? Woody Biomass Size Reduction ? for Forest Biorefinery J. Y. Zhu 5. Chemistry and Reactions of Forest Biomass in Biorefining S. Elumalai and X. J. Pan 6. The Influence of Lignin on the Enzymatic Hydrolysis of Pretreated Biomass Substrates Seiji Nakagame, Richard P. Chandra, and Jack N. Saddler Fuels from Lignocelluloses 7. Approaches To Deal with Toxic Inhibitors during Fermentation of Lignocellulosic Substrates T. L. Richardson, N. K. Harner, P. K. Bajwa, J. T. Trevors, and H. Lee 8. Hydrogen Production from Carbohydrates: A Mini-Review Y.-H. Percival Zhang Chemicals from Lignocelluloses 9. Chemicals from Hemicelluloses: A Review Feng Peng, Jun Li Ren, Feng Xu, and Run-Cang Sun 10. Chemicals from Lignin Based on Thermal Fusibility and Amphiphilicity Keiichi Koda, Satoshi Kubo, and Yasumitsu Uraki 11. Chemicals from Extractives Rodger P. Beatson Biomaterials from Lignocelluloses 12. Development and Properties of Nanocrystalline Cellulose Wadood Y. Hamad, Principal Scientist 13. Biofibers Y. Xu and R. M. Rowell 14. Development of Biodegradable Polymer Composites Long Jiang, Meng-Hsin Tsai, Scott Anderson, Michael P. Wolcott, and Jinwen Zhang Forest Biorefinery Based on Pulp and Paper Industrial Technologies 15. Modify Existing Pulp and Paper Mills for Biorefinery Operations Xiao Zhang, Michael G. Paice, and James Deng 16. Integrated Forest Biorefinery ? Sulfite Process Pedram Fatehi and Yonghao Ni 17. Integrated Forest Biorefineries ? Near-Neutral Process Adriaan van Heiningen, Joseph Genco, Sunghoon Yoon, Mehmet S. Tunc, Haixuan Zou, Jie Luo, Haibo Mao, and Hemant Pendse 18. Integrated Forest Biorefinery - Prehydrolysis/Dissolving Pulping Process Pedram Fatehi and Yonghao Ni Editors' Biographies Author Index Subject Index

The distribution and bioaccumulation of steroidal and phenolic endocrine disrupting chemicals (EDCs) were studied in various tissues of wild fish species from Dianchi Lake, China. In muscle tissue, 4-tert-octylphenol, 4-cumylphenol, 4-nonlyphenol and bisphenol A were detected in fish from each sampling site, with maximal concentrations of 4.6, 4.4, 18.9 and 83.5 ng/g dry weight (dw), respectively. Steroids (estrone, 17β-estradiol 17α-ethynylestradiol and estriol) were found at lower levels (

Fluorescent cellulose nanocrystals (CNCs) were prepared through a two-step approach. Reactive amino groups were first introduced onto the CNCs through a silanization reaction with 3-aminopropyltrimethoxysilane. The fluorescent moieties were then attached onto the cellulose by covalent grafting between the amino groups and 1-pyrenebutyric acid N-hydroxy succinimide ester or fluorescein isothiocyanate. The synthesized fluorescent CNCs were investigated and characterized with attenuated total reflectance Fourier transform infrared spectroscopy, ultraviolet–visible absorbance and fluorescence spectroscopy, confocal microscopy, and dynamic light scattering. The same fluorescent functionalization strategy could also be applied to other cellulose materials, such as microcrystalline cellulose and bulky paper sheets. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

We give a sufficient condition, which guarantees that for arbitrary Hamiltonian cycle C, there exists a [k, k + 1]-factor containing C. This improves a previous result of Cai, Li, and Kano [7].

Lodgepole pine from forest thinnings is a potential feedstock for ethanol production. In this study, lodgepole pine was converted to ethanol with a yield of 276 L per metric ton of wood or 72% of theoretical yield. The lodgepole pine chips were directly subjected to sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) pretreatment and then disk-milled; the recovered cellulose substrate was quais-simultaneously saccharified enzymatically and fermented to ethanol using commercial cellulases and Saccharomyces cerevisiae D5A. The liquor stream from the pretreatment containing hydrolyzed sugars mainly from hemicelluloses was fermented by the same yeast strain after detoxification using an XAD resin column. The SPORL pretreatment was conducted at 180 degrees C for a period of 25 min with a liquor-to-wood ratio of 3:1 (v/w) in a laboratory digester. Three levels of sulfuric acid charge (0.0%, 1.4%, and 2.2% on an oven dried wood basis in w/w) and three levels of sodium bisulfite charge (0.0%, 4.0%, and 8.0% in w/w) were applied. Mechanical and thermal energy consumption for milling and pretreatment were determined. These data were used to determine the efficiency of sugar recoveries and net ethanol energy production values and to formulate a preliminary mass and energy balance.

Enzymatic hydrolysis of lignocellulosic materials is significantly affected by cellulase adsorption onto the lignocellulosic substrates and lignin. The presence of lignin plays an important role in lignocellulosic hydrolysis and enzyme recycling. Three cellulase preparations (Celluclast, Spezyme CP, and MSUBC) were evaluated to determine their adsorption onto cellulolytic enzyme lignin (CEL) from steam-exploded Lodgepole pine (SELP) and ethanol (organosolv)-pretreated Lodgepole pine (EPLP). The adsorption affinity of cellulase (Celluclast) onto isolated lignin (CEL-EPLP and CEL-SELP) was slightly higher than that from corresponding EPLP and SELP substrates on the basis of the Langmuir constants. Effects of temperature, ionic strength, and surfactant on cellulase adsorption onto isolated lignin were also explored in this study. Thermodynamic analysis of enzyme adsorption onto isolated lignin (Gibbs free energy change DeltaG(0) approximately -30 kJ/mol) indicated this adsorption was a spontaneous process. The addition of surfactant (0.2% w/v) could reduce the adsorption of cellulase onto CEL-SELP by 60%. Two types of adsorption isotherm were compared for cellulase adsorption onto isolated lignin. A Langmuir adsorption isotherm showed better fit for the experimental data than a Freundlich adsorption isotherm.

Pyrene-labeled hydroxypropyl cellulose (HPC-Py) was synthesized through a condensation reaction between hydroxypropyl cellulose (HPC) and 1-pyrenebutyric acid (Py). A hybrid (HPC/MWNTs) of the HPC-Py and multiwalled carbon nanotubes (MWNTs) was prepared through a noncovalent method. Temperature-variable UV-vis spectra indicated that the HPC-Py had a lower critical solution temperature of about 44 degrees C in water. (1)H NMR, UV-vis, Raman, and fluorescence spectra were used to systematically investigate the pi-pi stacking interaction between the HPC-Py and MWNTs. Dispersion experiments showed the HPC/MWNTs hybrids could be well dispersed in water and many organic solvents.

The relative metal sorption ability of kraft and organosolv lignins was examined as a function of solution chemistry (pH, ionic strength (I), sorbate-to-sorbent ratio) and reaction time. The surface charge characteristics and functional group composition of these lignins, especially kraft lignin, are favorable for metal sorption. Sorption of Cu and Cd increased with increasing pH and decreasing I. Description of sorption isotherms required the more complex Sips equation, as compared to the simpler Langmuir and Freundlich formulations, indicative of the presence of binding sites with varying affinities on these lignin biosorbents. Sorption capacity varied in the following order: softwood organosolv lignin

This study established a novel process using sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) for robust and efficient bioconversion of softwoods. The process consists of sulfite treatment of wood chips under acidic conditions followed by mechanical size reduction using disk refining. The results indicated that after the SPORL pretreatment of spruce chips with 8–10% bisulfite and 1.8–3.7% sulfuric acid on oven dry (od) wood at 180 °C for 30 min, more than 90% cellulose conversion of substrate was achieved with enzyme loading of about 14.6 FPU cellulase plus 22.5 CBU β-glucosidase per gram of od substrate after 48 h hydrolysis. Glucose yield from enzymatic hydrolysis of the substrate per 100 g of untreated od spruce wood (glucan content 43%) was about 37 g (excluding the dissolved glucose during pretreatment). Hemicellulose removal was found to be as critical as lignin sulfonation for cellulose conversion in the SPORL process. Pretreatment altered the wood chips, which reduced electric energy consumption for size reduction to about 19 Wh/kg od untreated wood, or about 19 g glucose/Wh electricity. Furthermore, the SPORL produced low amounts of fermentation inhibitors, hydroxymethyl furfural (HMF) and furfural, of about 5 and 1 mg/g of untreated od wood, respectively. In addition, similar results were achieved when the SPORL was applied to red pine. By building on the mature sulfite pulping and disk refining technologies already practiced in the pulp and paper industry, the SPORL has very few technological barriers and risks for commercialization.

Hybrid poplar (Populus nigra x P. maximowiczii) chips were pretreated using an organosolv ethanol process. The effect of pretreatment conditions (temperature, time, catalyst, and ethanol concentration) on the substrate characteristics, including fiber size, crystallinity, and degree of polymerization of cellulose, was investigated using an experimental matrix designed with response surface methodology. The conditions ranged 155-205 degrees C, 26-94 min, 0.83-1.67% catalyst (H(2)SO(4)) on oven-dry wood chip (w/w), and 25-75% ethanol concentration (v/v). The results indicated that the substrate characteristics are controllable and predictable. Desirable substrates can be prepared by fine-tuning the processing parameters. The regression models developed, allowed the quantitative prediction of the substrate characteristics from the pretreatment conditions used.

Lodgepole pine (Pinus contorta) killed by mountain pine beetle (Dendroctonus ponderosae) (BLP) was compared with healthy lodgepole pine (HLP) for bioconversion to ethanol and high-value co-products. The BLP and HLP chips were pretreated using an ethanol organosolv process at a variety of severities. It was shown that the BLP was easier to pretreat and delignify than were the HLP chips. The resulting pretreated BLP substrate had a lower residual lignin, lower degree of polymerization of cellulose, lower cellulose crystallinity, smaller fiber size and thereby a better enzymatic hydrolysability than did the HLP substrates. However, under the same conditions, the BLP showed lower substrate yield and cellulose recovery than did the HLP, which likely resulted from the excessive hydrolysis and subsequent decomposition of the cellulose and hemicellulose during the pretreatment. The BLP wood yielded more ethanol organosolv lignin than was obtained with the HLP material. The HLP lignin had a lower molecular weight and narrower distribution than did the BLP lignin. It appears that the beetle killed LP is more receptive to organosolv pretreatment other than a slightly lower recovery of carbohydrates.

Although the structure and function of cellulase systems continue to be the subject of intense research, it is widely acknowledged that the rate and extent of the cellulolytic hydrolysis of lignocellulosic substrates is influenced not only by the effectiveness of the enzymes but also by the chemical, physical and morphological characteristics of the heterogeneous lignocellulosic substrates. Although strategies such as site-directed mutagenesis or directed evolution have been successfully employed to improve cellulase properties such as binding affinity, catalytic activity and thermostability, complementary goals that we and other groups have studied have been the determination of which substrate characteristics are responsible for limiting hydrolysis and the development of pretreatment methods that maximize substrate accessibility to the cellulase complex. Over the last few years we have looked at the various lignocellulosic substrate characteristics at the fiber, fibril and microfibril level that have been modified during pretreatment and subsequent hydrolysis. The initial characteristics of the woody biomass and the effect of subsequent pretreatment play a significant role on the development of substrate properties, which in turn govern the efficacy of enzymatic hydrolysis. Focusing particularly on steam pretreatment, this review examines the influence that pretreatment conditions have on substrate characteristics such as lignin and hemicellulose content, crystallinity, degree of polymerization and specific surface, and the resulting implications for effective hydrolysis by cellulases.

Softwoods are generally considered to be one of the most difficult lignocellulosic feedstocks to hydrolyze to sugars for fermentation, primarily owing to the nature and amount of lignin. If the inhibitory effect of lignin can be significantly reduced, softwoods may become a more useful feedstock for the bioconversion processes. Moreover, strategies developed to reduce problems with softwood lignin may also provide a means to enhance the processing of other lignocellulosic substrates. The Forest Products Biotechnology Group at the University of British Columbia has been developing softwood-to-ethanol processes with SO2-catalyzed steam explosion and ethanol organosolv pretreatments. Lignin from the steam explosion process has relatively low reactivity and, consequently, low product value, compared with the high-value coproduct that can be obtained through organosolv. The technical and economic challenges of both processes are presented, together with suggestions for future process development.

This research investigated a novel process to prepare polyester from corn stover through liquefaction and crosslinking processes. First, corn stover was liquefied in organic solvents (90 wt% ethylene glycol and 10 wt% ethylene carbonate) with catalysts at moderate temperature under atmospheric pressure. The effect of liquefaction temperature, biomass content, and type of catalyst, such as H2SO4, HCl, H3PO4, and ZnCl2, was evaluated. Higher liquefaction yield was achieved in 2 wt% sulfuric acid, 1/4 (w/w) stover to liquefying reagent ratio; 160 degrees C temperature, in 2 h. The liquefied corn stover was rich in polyols, which can be directly used as feedstock for making polymers without further separation or purification. Second, polyester was made from the liquefied corn stover by crosslinking with multifunctional carboxylic acids and/or cyclic acid anhydrides. The tensile strength of polyester is about 5 MPa and the elongation is around 35%. The polyester is stable in cold water and organic solvents and readily biodegradable as indicated by 82% weight loss when buried in damp soil for 10 mo. The results indicate that this novel polyester could be used for the biodegradable garden mulch film production.

Twenty-one organosolv ethanol lignin samples were prepared from hybrid poplar (Populus nigra xP. maximowiczii) under varied conditions with an experimental matrix designed using response surface methodology (RSM). The lignin preparations were evaluated as potential antioxidants. Results indicated that the lignins with more phenolic hydroxyl groups, less aliphatic hydroxyl groups, low molecular weight, and narrow polydispersity showed high antioxidant activity. Processing conditions affected the functional groups and molecular weight of the extracted organosolv ethanol lignins, and consequently influenced the antioxidant activity of the lignins. In general, the lignins prepared at elevated temperature, longer reaction time, increased catalyst, and diluted ethanol showed high antioxidant activity. Regression models were developed to enable the quantitative prediction of lignin characteristics and antioxidant activity based on the processing conditions.

An organosolv process involving extraction with hot aqueous ethanol has been evaluated for bioconversion of hybrid poplar to ethanol. The process resulted in fractionation of poplar chips into a cellulose-rich solids fraction, an ethanol organosolv lignin (EOL) fraction, and a water-soluble fraction containing hemicellulosic sugars, sugar breakdown products, degraded lignin, and other components. The influence of four independent process variables (temperature, time, catalyst dose, and ethanol concentration) on product yields was analyzed over a broad range using a small composite design and response surface methodology. Center point conditions for the composite design (180 degrees C, 60 min, 1.25% H(2)SO(4), and 60% ethanol), yielded a solids fraction containing approximately 88% of the cellulose present in the untreated poplar. Approximately 82% of the total cellulose in the untreated poplar was recovered as monomeric glucose after hydrolysis of the solids fraction for 24 h using a low enzyme loading (20 filter paper units of cellulase/g cellulose); approximately 85% was recovered after 48 h hydrolysis. Total recovery of xylose (soluble and insoluble) was equivalent to approximately 72% of the xylose present in untreated wood. Approximately 74% of the lignin in untreated wood was recovered as EOL. Other cooking conditions resulted in either similar or inferior product yields although the distribution of components between the various fractions differed markedly. Data analysis generated regression models that describe process responses for any combination of the four variables.

There may be in great oscillation and degradation in ATM networks due to higher-priori traffic, such as CBR/VBR, multiple-loop delays, measured disturbance and dynamical variants. An adaptive predictive congestion control is presented for multi-node ATM networks, in which real-time rate control is realized by online estimation of networks parameters, and closed-loop stability is guaranteed, and the extent and duration of congestion has been greatly reduced, and the utilization is maximized and packet loss rate is decreased. The effectiveness of the proposed methods is demonstrated by the simulation results.

This paper introduces a robot simulation, monitoring and control system based on network and lava. This system uses java to establish monitoring GUI and offers communication port module at the same time. Robot software system offers usual movement modules. Thus, the system can complete multi-robot cooperation simulation, experiments and monitoring by intercommunication. The experiment results indicate that the system implements the functions well.

With the renovation of Boston Harbor's Deer Island wastewater treatment plant and the extension of its diffuser pipes 15 km further into Massachusetts Bay, there arose the question whether the increased load of its secondary-treated wastewater contained significant amounts of phenolic endocrine disrupting chemicals (EDCs). Sampling from an oceanographic research vessel during the summers of 2003 and 2004 allowed for a unique opportunity to obtain clam, zooplankton, and bottom sediment samples. The samples were prepared by enhanced organic-solvent microwave digestion, followed by solid-phase extraction (SPE), derivatization and then analyzed by gas chromatography-mass spectrometry (GC-MS) or left un-derivatized and analyzed by LC-UV and liquid chromatography-mass spectrometry (LC-MS). The marine samples, especially parts of the clams, zooplankton and certain bottom sediments were found to contain primarily bisphenol A (BPA) at concentrations of 1-30 ng/g.

Pulps with residual lignin ranging from 6.4–27.4% (w/w) were prepared from mixed softwoods using a proprietary biorefining technology (the Lignol process) based on aqueous ethanol organosolv extraction. The pulps were evaluated for bioconversion using enzymatic hydrolysis of the cellulose fraction to glucose and subsequent fermentation to ethanol. All pulps were readily hydrolyzed without further delignification. More than 90% of the cellulose in low lignin pulps (≤18.4% residual lignin) was hydrolyzed to glucose in 48 h using an enzyme loading of 20 filter paper units/g cellulose. Cellulose in a high lignin pulp (27.4% residual lignin) was hydrolyzed to >90% conversion within 48 h using 40 filter paper units/g. The pulps performed well in both sequential and simultaneous saccharification and fermentation trials indicating an absence of metabolic inhibitors. Chemical and physical analyses showed that lignin extracted during organosolv pulping of softwood is a suitable feedstock for production of lignin-based adhesives and other products due to its high purity, low molecular weight, and abundance of reactive groups. Additional co-products may be derived from the hemicellulose sugars and furfural recovered from the water-soluble stream. © 2005 Wiley Periodicals, Inc.

Adult male crayfish Procambarus clarkii exist in two morphotypes. They continue to molt as adults, switching between Form Is and Form IIs. Form Is are primary reproductive types, with large chelae and spines on the ischiopodites of the third and fourth pair of walking legs. Form IIs are non-reproductive types with smaller chelae and no spines on the ischiopodites. We investigated the hormonal control of these transitions in two ways, by eyestalk ablation and by methyl farnesoate (MF) treatments. Eyestalk ablation accelerates molting and increases MF levels in the blood. MF is a hormone that regulates both reproduction and morphogenesis. MF concentrations were determined in two ways. The hemolymph samples were extracted first, then purified, using normal phase HPLC. The fractions containing MF were collected and analyzed for MF concentration, utilizing both internal and external standards by GC/MS. The other hemolymph samples were analyzed from individual animals by HPLC. The concentrations of ecdysteroids were determined by radioimmunoassay. In the control animals, 4 out of 4 untreated Form I males molted into Form II, while 6 out of 7 Form IIs molted into Form Is. Eight of 8 ablated Form Is molted into Form IIs as expected, while 5 of 5 ablated Form IIs molted into Form IIs, instead of Form Is. MF treatment of intact animals resulted in 6 of 7 Form Is becoming Form IIs and 5 of 6 Form IIs becoming Form IIs. These results were highly significant in comparison of Form I and IIs in each treatment (eyestalk intact, eyestalk ablated and eyestalk intact with MF) by a chi square analysis, P = 0.006 , P 0.0005 , and P = 0.013 , respectively. MF premolt blood levels suggested that Form IIs were produced in the presence of 1.3 ng/ml MF, while Form Is result from MF levels less than 0.5 ng/ml. Since both eyestalk ablation and MF treatment resulted in the failure of Form IIs becoming Form Is, it was concluded that the control of morphogenesis of primary reproductives (Form Is) depends on a low level of MF prior to the molt, while Form IIs are formed in the presence of increased levels of MF.

Good enzymatic hydrolysis of steam-exploded Douglas fir wood (SEDW) cannot be achieved owing to the very high lignin content (40%) that remains associated with this substrate. Thus, in this study, we investigated the use of alkali-oxygen treatment as a posttreatment to delignify SEDW and also considered the enzymatic hydrolyzability of the delignified SEDW. The results showed that under optimized conditions of 15% NaOH, 5% consistency, 110 degrees C, and 3 h, approx 84% of the lignin in SEDW could be removed. The resulting delignified SEDW had good hydrolyzability, and cellulose-to-glucose conversion yields of over 90 and 100% could be achieved within 48 h with 20 and 40 filter paper units/g of cellulose enzyme loadings, respectively. It was also indicated that severe conditions, such as high NaOH concentration and high temperature, should not be utilized in oxygen delignification of SEDW in order to avoid extensive condensation of lignin and significant degradation of cellulose.

This study experimentally quantified the formation of organic sulfur compounds in a commercial SuperBatch kraft pulping process using a laboratory pilot-scale digester. The results indicate that wood chips not only can adsorb HS- but also methyl mercaptan (MM) in the black liquor used for pretreatment during the two pretreatment stages. The absorption rate of MM is much faster than that of HS-. In the third stage of SuperBatch pulping, the rate of formation of MM and dimethyl sulfide (DMS) is very similar to that found in conventional batch kraft pulping processes. The study examined the applicability of the phase transition cooking (PTC) concept for reducing organic sulfur compounds in pulping, previously developed in laboratory batch pulping using a bomb-type digester, in a SuperBatch process. It was confirmed that there is a phase transition point (PTP) corresponding to PTC in SuperBatch pulping beyond which further delignification significantly increases the formation of volatile organic sulfur compounds. The results indicate that a 40% reduction of TRS formation can be achieved by using PTC.

A novel microwave-assisted extraction (MAE) method has been developed for the extraction and determination of tanshinones (tanshinone IIA, cryptotanshinone and tanshinone I) from the root of Salvia miltiorrhiza bunge with analysis by HPLC. Various experimental conditions were investigated to optimize the percentage extraction. Under appropriate MAE conditions, such as ethanol concentrations of 95% (v/v), MAE for 2 min, liquid/solid ratio of 10:1 (ml/g), the percentage extraction can reach high in a short time. The percentage extraction (tanshinone IIA: 0.29%; cryptotanshinone: 0.23%; tanshinone I: 0.11%) by MAE was the same or even higher than conventional extraction methods. MAE only needs 2 min, but extraction at room temperature, heat reflux extraction, ultrasonic extraction and Soxhlet extraction need 24 h, 45 min, 75 min and 90 min, respectively. MAE was also available in pilot plant form for larger scale extraction.

In the present study, a microwave-assisted extraction (MAE) technique has been developed for the extraction of glycyrrhizic acid (GA) from licorice rest. Various experimental conditions, such as extraction time, different ethanol and ammonia concentration, liquid/solid ratios, pre-leaching time before MAE and material size for the MAE procedure were investigated to optimize the efficiency of the extraction. Under appropriate MAE conditions, such as extraction times of 4-5 min, ethanol concentrations of 50-60% (v/v), ammonia concentrations of 1-2% (v/v) and liquid/solid ratios of 10:1(ml/g), the recovery of GA from licorice root with MAE was equivalent with conventional extraction methods. Those methods include extraction at room temperature (ERT), the traditional Soxhlet extraction, heat reflux extraction and ultrasonic extraction. Due to the considerable savings in time and solvent, MAE was more effective than the conventional methods. This novel method is suitable for fast extraction of GA from Licorice root. (C) 2000 Elsevier Science S.A. All rights reserved.

Background Lignin is an integral component of the plant cell wall matrix but impedes the conversion of biomass into biofuels. The plasticity of lignin biosynthesis should permit the inclusion of new compatible phenolic monomers such as flavonoids into cell wall lignins that are consequently less recalcitrant to biomass processing. In the present study, epigallocatechin gallate (EGCG) was evaluated as a potential lignin bioengineering target for rendering biomass more amenable to processing for biofuel production. Results In vitro peroxidase-catalyzed polymerization experiments revealed that both gallate and pyrogallyl (B-ring) moieties in EGCG underwent radical cross-coupling with monolignols mainly by β–O–4-type cross-coupling, producing benzodioxane units following rearomatization reactions. Biomimetic lignification of maize cell walls with a 3:1 molar ratio of monolignols and EGCG permitted extensive alkaline delignification of cell walls (72 to 92%) that far exceeded that for lignified controls (44 to 62%). Alkali-insoluble residues from EGCG-lignified walls yielded up to 34% more glucose and total sugars following enzymatic saccharification than lignified controls. Conclusions It was found that EGCG readily copolymerized with monolignols to become integrally cross-coupled into cell wall lignins, where it greatly enhanced alkaline delignification and subsequent enzymatic saccharification. Improved delignification may be attributed to internal trapping of quinone-methide intermediates to prevent benzyl ether cross-linking of lignin to structural polysaccharides during lignification, and to the cleavage of ester intra-unit linkages within EGCG during pretreatment. Overall, our results suggest that apoplastic deposition of EGCG for incorporation into lignin would be a promising plant genetic engineering target for improving the delignification and saccharification of biomass crops.

A novel cellulase-mimetic solid catalyst, sulfonated chloromethyl polystyrene resin (CP-SO3H), containing cellulose-binding sites (–Cl) and catalytic sites (–SO3H) was synthesized for hydrolyzing cellulose. Cellobiose could be completely hydrolyzed in 2–4 hours at 100–120 °C by CP-SO3H, and microcrystalline cellulose (Avicel) could be hydrolyzed into glucose with a yield of 93% within 10 hours at moderate temperature (120 °C). The apparent activation energies for the hydrolysis of cellobiose and Avicel with CP-SO3H were approximately 78 and 83 kJ mol−1, respectively, which are much lower than those for the hydrolysis of cellobiose and cellulose with sulfuric acid (133 and 170 kJ mol−1, respectively) but higher than that with cellulase (3–50 kJ mol−1). Low activation energy allows the CP-SO3H-catalyzed hydrolysis to proceed at low temperature, which reduces energy consumption and avoids undesirable sugar degradation. The low activation energy of CP-SO3H might be attributed to its ability to adsorb/attract cellobiose and cellulose and to disrupt hydrogen bonds of cellulose.