Search

Influence of water content on the expression of lignocellulolytic enzymes by Phanerochaete chrysosporium remains unclear. This work compares the enzyme production profiles of P. chrysosporium during solid-state and submerged fermentation. There were 110 and 64 extracellular carbohydrate-active enzymes identified in solid-state and submerged fermentation respectively, among which 57 enzymes were common to both of the secretomes. P. chrysosporium secreted more cellulases (especially lytic polysaccharide monooxygenase) and hemicellulases during solid-state fermentation while the proportion of enzyme containing carbohydrate-binding module was higher for submerged fermentation. Although its activities were weaker, the enzyme cocktail from submerged fermentation was surprisingly more effective in hydrolysis at low substrate loading. This advantage of enzymes from submerged fermentation was mainly attributed to carbohydrate-binding module because more xylanases bound with substrate at the beginning of hydrolysis. These results reveal the influence of fermentation conditions on enzyme produced by P. chrysosporium for the first time and show the importance of carbohydrate-binding module in the hydrolysis process of lignocellulose. • Secrotomes of Phanerochaete chrysosporium under SSF and SmF were compared. • P. chrysosporium secreted more kinds of enzyme with higher activities under SSF. • Enzyme cocktail from SmF was more effective in hydrolysis at low substrate loading. • Advantage of enzymes from SmF in hydrolysis was mainly attributed to more CBMs. [ABSTRACT FROM AUTHOR]

Herein, we report the secretome of Penicillium chrysogenum P33 under induction of lignocellulose for the first time. A total of 356 proteins were identified, including complete cellulases and numerous hemicellulases. Supplementing a commercial cellulase with increasing dosage of P33 enzyme cocktail from 1 to 5 mg/g substrate increased the release of reducing sugars from delignified corn stover by 21.4% to 106.8%. When 50% cellulase was replaced by P33 enzyme cocktail, release of reducing sugars was 78.6% higher than with cellulase alone. Meanwhile, glucan and xylan conversion was increased by 37% and 106%, respectively. P33 enzyme cocktail also enhanced commercial cellulase hydrolysis against four different delignified lignocellulosic biomass. These findings demonstrate that mixing appropriate amount of P33 cocktail with cellulase improves polysaccharide hydrolysis, suggesting P33 enzymes have great potential for industrial applications. [ABSTRACT FROM AUTHOR]

In this study, lignite was degraded using a purified esterase from Penicillium decumbens P6 for the first time. The esterase was purified using ammonium sulfate precipitation, anion exchange and gel filtration chromatography. The recovery and purification yield of the enzyme were 15% and 83 folds, respectively. The molecular weight of the purified enzyme was about 45 kDa. Both crude and purified esterases were studied for lignite depolymerization. The tendency of depolymerization by crude enzyme was consistent with the enzyme secreted in the medium. Along with the increased purified esterase concentration from 8 to 50 mg/ml, A 450 value increased from 0.38 to 2.08. The contribution of esterase to the depolymerization was about 40% in the crude supernatant. Compared with aHA (crude lignite humic acid), bHA (esterase degraded lignite humic acid) has a lower percentage of aromatic carbon and ester groups, but a higher percentage of aliphatic carbon. bHA can promote the growth of asparagus lettuce. The results demonstrated that lignite was depolymerized by the purified esterase and evidenced the potential of esterase application in conversion of lignite into compounds with high bioactivities. [ABSTRACT FROM AUTHOR]

Phosphate accumulating bacterium Pseudomonas stutzeri YG-24 exhibited efficient heterotrophic nitrification and aerobic denitrification ability. Single factor experiments showed that both heterotrophic nitrification and aerobic denitrification occurred with sodium citrate as carbon source and lower C/N ratio of 8. High average NH 4 + -N, NO 2 − -N and NO 3 − -N removal rates of 8.75, 7.51 and 7.73 mg L −1 h −1 were achieved. The application of strain YG-24 in wastewater samples resulted in TN, NH 4 + -N, NO 2 − -N, NO 3 − -N and P removal efficiencies of 85.28%, 88.13%, 86.15%, 70.83% and 51.21%. Sequencing and quantitative amplification by real-time PCR of napA , nirS and ppk showed that nitrogen removal pathway of strain YG-24 was achieved through heterotrophic ammonium nitrification coupled with fast nitrite denitrification (NH 4 + -N to NO 2 − -N and then to gaseous nitrogen) directly. These results demonstrated the strain as a suitable candidate to simultaneously remove both nitrogen and phosphate in wastewater treatment. [ABSTRACT FROM AUTHOR]

Algae lipid production combined with heavy metal removal is a cost-effective and environment-friendly method for algae biofuel production and hazardous waste treatment. Chlorella minutissima UTEX 2341 had strong resistance to cadmium, copper, manganese and zinc ions under heterotrophic culture condition and could efficiently remove them through intracellular accumulation and extracellular immobilization. Meanwhile, lipid accumulation was not inhibited by heavy metals. Instead, the algae lipid content significantly increased by 21.07% and 93.90%, respectively with the addition of cadmium and copper. Furthermore, the heavy metal residue in lipid was within μg range and satisfied the commercial standard. This artificial wastewater-algae biofuel-heavy-metal integrated utilization technology offered a new alternative solution to the problems of energy shortage and environmental pollution. [ABSTRACT FROM AUTHOR]

The vibration and damping characteristics of free-free composite sandwich cylindrical shell with pyramidal truss-like cores have been conducted using the Rayleigh-Ritz model and finite element method. The predictions for the modal properties of composite sandwich cylindrical shell with pyramidal truss-like cores showed good agreement with the experimental tests. The influences of fiber ply angles on the natural frequency and damping loss factor were investigated. Three types of such composite sandwich cylindrical shells were manufactured using a hot press molding method and the relevant modal characteristics of various sandwich cylindrical shells could be obtained by modal tests. It can be found that modal strain energy approach was effective to estimate the structural damping loss factors and the variation of damping for each vibration modes could be explained suitably through the contributions of each strain energy components. Results showed that the structural damping loss factors not only depended on inherent material damping, but also relied on the vibration modes. The natural frequencies of composite sandwich cylindrical shell increased with the increasing of the ply angle of the inner and outer curve face sheets, whereas the damping loss factors of present shells did not increase monotonically. [ABSTRACT FROM AUTHOR]

Abstract: The vibration and damping performances of hybrid carbon fiber composite pyramidal truss sandwich panels with viscoelastic layers embedded in the face sheets were investigated in this paper. Hybrid carbon fiber composite pyramidal truss sandwich panels containing different thickness of viscoelastic layers were manufactured using a hot press molding method. Analytical models based on modal strain energy approach were developed using ABAQUS software to estimate the damping property of the hybrid sandwich structures. A set of modal tests were carried out to investigate the vibration and damping characteristics of such hybrid sandwich panels with or without viscoelastic layers. The damping loss factors of composite slender beams with different fiber orientations were tested to determine the constitutive damping properties of parent materials for such hybrid sandwich panels. The numerical simulation results showed good agreement with the experimental tests. The damping loss factors of hybrid sandwich panels increased distinctly compared with previous sandwich panels due to the viscoelastic layer embedded in the face sheets. [Copyright &y& Elsevier]

Abstract: This study is concerned with an actual collapse testing under the flap-wise loading for a large full-scale composite wind turbine blade, and a discussion is conducted to assess and evaluate the structural response of the blade during loading and after collapse by correlating experimental findings with numerical model predictions. A videometrics technique is adopted to measure the integral deformation and the local deformation of the wind turbine blade under the flap-wise loading. The measured results show that the displacement of the blade tip is up to 11m at the ultimate load which is 160% of the extreme design load for the tested blade. A simple method is proposed to identify the exact failure location of the blade based on the deformation data. The thorough analysis results indicate that the aerodynamic shells debonding from the adhesive joints is the initial failure mechanism causing a progressive collapse of the blade structure. [Copyright &y& Elsevier]

Abstract: The size of wind turbine blades is expected to increase considerably in the future. Since the modern wind turbine blade is generally large-scale, faulty design production results in high expense. To achieve a desired wind turbine blade, a better understanding of the structural behavior on different scale is necessary. Although the structural deformation of the full-scale blade under various loads is an important parameter in the analysis of structural behavior and the blade’s performance, there are many difficulties in an accurate deformation measurement of the large-scale wind turbine blade. A videometric technique reported here was developed to determine the large-scale blade deformations. The technique principle and methodology will be presented in the current paper, which involves the detail of implementation in the large-scale blade deformation measurement. Some application examples with the obtained data and their analysis are presented, which demonstrates the technique’s application on large-scale wind turbine blade, and which is relevant to understanding the structural behavior of wind turbine blade in the full-scale tests and during operation. The videometric technique will be useful for structural investigation of composite wind turbine blades. A wide variety of other applications, especially those involving fieldwork, could exploit this implementation of videometric. [Copyright &y& Elsevier]

Abstract: To reduce the cost of algal biomass production, mathematical model was developed for the first time to describe microalgae growth, lipid production and glycerin consumption under photoheterotrophic conditions based on logistic, Luedeking–Piret and Luedeking–Piret-like equations. All experiments were conducted in a 2L batch reactor without considering CO2 effect on algae’s growth and lipid production. Biomass and lipid production increased with glycerin as carbon source and were well described by the logistic and Luedeking–Piret equations respectively. Model predictions were in satisfactory agreement with measured data and the mode of lipid production was growth-associated. Sensitivity analysis was applied to examine the effects of certain important parameters on model performance. Results showed that S0, the initial concentration of glycerin, was the most significant factor for algae growth and lipid production. This model is applicable for prediction of other single cell algal species but model testing is recommended before scaling up the fermentation of process. [ABSTRACT FROM AUTHOR]

Abstract: Sugarcane bagasse (SCB) is a residual product of sugar processing, containing mainly lignocellulose. The biodegradation of cellulose is an economical approach to recycling SCB. To obtain an effective microbial community and study the SCB biodegradation process, a SCB-degrading mesophilic microbial community, EMSD13, growing at 50°C was isolated. More than 77% of alkali pretreated SCB was degraded and over 83% of the cellulose it contained was utilized by the EMSD13 community within 6 days. To understand the biodegradation procedure of EMSD13, extracellular and SCB-absorbable cellulases were analyzed. The peak activity (42mU/mL) of the extracellular cellulase in the supernatant occurred on the 3rd day of incubation. About 73.6mg of substrate-bound proteins with a cellulase activity of 61.1mU/mg were recovered from residual SCB by eluting with 3M guanidine hydrochloride. Also, 15.9mg of proteins with 28.6mU/mg of cellulase activity were obtained from residual SCB by eluting with 6M urea. SDS-PAGE analysis showed that cellulases in both elutes were similar, but most differed from those in the supernatant. This is the first report on substrate-bound cellulases from a microbial community. [Copyright &y& Elsevier]

Abstract: In this study, a novel alkaliphilic extracellular endo-β-1,4-xylanase was purified from the culture filtrate of microbial community EMSD5, which could grow in liquid culture fermentation under static condition with corn stover as inducement. Single step purification was achieved using anion exchange chromatography. The purified enzyme showed a single band on SDS polyacrylamide gel electrophoresis (SDS-PAGE) with an apparent molecular weight of 22kDa and pI of 7.1. Stimulation of the activity by β-mercaptoethanol, and dithiotheritol (DTT) was observed. Moderately thermostable xylanase showed optimum activity at 50°C in pH 8.0. 16S rDNA clone library analysis indicated this community was mainly composed of bacteria related to genera Clostridium, Acinetobacter, Bacteroides, Lysinibacillus and Dysgonomonas. The present work reports for the first time the purification and characterization of an alkaliphilic xylanase from a microbial community, and the alkaliphilicity and moderate thermostability of this xylanase may have potential implications in pulp and paper industries. [Copyright &y& Elsevier]

Abstract: The process involved in lignite degradation/solubilization by Penicillium decumbens P6 was studied. P6 secreted some unknown alkaline substance and increased the pH of the medium as it grew. Meanwhile, it excreted some surfactants that might be involved in lignite degradation. The most important aspect in this study was that P6 could excrete some extracellular enzymes that might participate in the lignite degradation. With the induction of lignite, the activities of peroxidases and esterases, two classes of enzymes capable of attacking lignite, were increased in the cell-free filtrate of the culture. [Copyright &y& Elsevier]

• A novel bifunctional xylanase/feruloyl esterase (rXyn10A/Fae1A) was obtained. • The highest ferulic acid yield (7.31 mg/g substrate) was produced by rXyn10A/Fae1A. • Inter-domain synergism of rXyn10A/Fae1A is essential for the release of ferulic acid. • Recombinant E. coli was constructed and secreted the bifunctional enzyme out of cells. • Co-production of ferulic acid and XOSs during the cultivation of recombinant E. coli. Liberating high value-added compounds ferulic acid (FA) and xylo-oligosaccharides (XOSs) from agricultural residues is a promising strategy for the utilization of lignocellulose. In this study, a bifunctional xylanase/feruloyl esterase from bacterial consortium EMSD5 was heterogeneously expressed in Escherichia coli. Depending on the inter-domain synergism of the recombinant enzyme rXyn10A/Fae1A, high yields of FA (2.78, 1.82, 1.15 and 7.31 mg/g substrate, respectively) were obtained from 20 mg in-soluble wheat arabinoxylan, de-starched wheat bran, ultrafine-grinding corn stover and steam-exploded corncob. Meanwhile, 3.210, 1.235, 1.215 and 0.823 mg xylose/XOSs were also released. For cost-saving enzyme production, we firstly constructed a recombinant E. coli , which could secrete the bifunctional xylanase/feruloyl esterase out of cells. When the recombinant E. coli was cultured in medium containing 200 mg de-starched wheat bran, 474 μg FA and 18.2 mg xylose/XOSs were also detected. Hence, rXyn10A/Fae1A and the recombinant strain showed great applied potential for FA and XOSs production. [ABSTRACT FROM AUTHOR]

• Bacterial consortium EMSD5 produced isopropanol from xylans efficiently. • 7.00 g/L isopropanol was produced from unpretreated corncob by consortia-based CBP. • Arabinose residues of xylan could enhance the CBP performance. • Clostridium beijerinckii and lignocellulose degraders performed CBP synergistically. Consolidated bioprocessing (CBP) of lignocellulose by bacterial consortium for isopropanol production is considered as the most promising strategy. However, low utilization of xylan caused by the complex sidechain structure remains inhibit the conversion of full-biomass. In this study, isopropanol production from different lignocelluloses by the consortium EMSD5 through CBP was performed. A total of 7.00 g/L of isopropanol was obtained from corncob by optimizing fermentation conditions. Isopropanol production by EMSD5 was mainly based on utilizing xylan in corncob and isopropanol titer was increased by 47.71% and reached up to 8.39 g/L using arabinoxylan compared with linear xylan. The analysis of community structures and the isolation of key strain confirmed the enrichment of the isopropanol producer, Clostridium beijierinckii , in the bacterial community when it was incubated with corn glucuronoarabinoxylan and the cooperation between C. beijerinckii and lignocellulose degraders. The unique features of EMSD5 could lead to large-scale isopropanol production using lignocellulose. [ABSTRACT FROM AUTHOR]

[Display omitted] • 28 PPCPs detected with concentrations of 45.19–1453.58 ng/L in water from the Tibet. • High animal vaccine consumption is main source of PPCPs in Qinghai-Tibet Plateau. • CAF, NOR, CTC, CIP, TCN, OTC, AZN, and DOX accounts for over 90% of the total PPCPs. • Excessive consumption of PPCPs by livestock breeding was the main emission source. • NOR, CTC, TCN, CAF, and CBZ pose high long-term ecological risks to aquatic biota. As the third pole of the world and Asia's water tower, the Tibetan Plateau experiences daily release of pharmaceutical and personal care products (PPCPs) due to increasing human activity. This study aimed to explore the potential relationship between the concentration and composition of PPCPs and human activity, by assessing the occurrence of PPCPs in areas of typical human activity on the Qinghai-Tibet Plateau and evaluating their ecological risk. The results indicate that 28 out of 30 substances were detected in concentrations ranging from less than 1 ng/L to hundreds of ng/L, with the average concentration of most PPCPs in the Tibet Autonomous Region being higher than that in Qinghai Province. Among the detected substances, CAF, NOR, CTC, CIP, TCN, OTC, AZN, and DOX accounted for over 90% of the total concentration. The emission sources of PPCPs were identified by analyzing the correlation coefficients of soil and water samples, with excess PPCPs used by livestock breeding discharged directly into soil and then into surface water through leaching or runoff. By comparing the concentration and composition of PPCPs with those in other regions, this study found that CIP, ENR, LOM, NOR, CTC, DOX, OTC, and TCN were the most commonly used PPCPs in the Qinghai-Tibet Plateau. To assess the ecological risk of PPCPs, organisms at different trophic levels, including algae, crustaceans, fish, and insects, were selected. The prediction of the no effect concentration of each PPCP showed that NOR, CTC, TCN, CAF, and CBZ may have deleterious effects on water biota. This study can assist in identifying the emission characteristics of PPCPs from different types and intensities of human activities, as well as their occurrence and fate during the natural decay of aquatic systems. [ABSTRACT FROM AUTHOR]

• A compact acoustic wave amplifier based on non-adiabatic compression of sound in metamaterial waveguides is proposed. • It is found that the combined effects of structural discontinuity and thermal viscous dissipations in the metamaterial waveguides is the key to reduce the size of metamaterial device and optimize its sound amplification capability. • The idea of achieving miniaturized metamaterial devices based on non-adiabatic fast wave compression and amplification provides a novel technique to develop acoustic wave amplifiers, which could be practically used in many applications. Inspired by the optical non-adiabatic wave propagation effect in plasmonic waveguides, we explore the acoustic non-adiabatic wave compression effect in acoustic metamaterial waveguides, and demonstrate its potential for the development of compact metamaterial devices with significant sound amplification capability. In particular, our numerical and experimental results have shown that there exists combined effects of structure discontinuity and thermal viscous dissipations in the metamaterial waveguides, which is essential to reduce the size of metamaterial device and optimize its field enhancement capability. Our work provides a new way to design high-performance and compact metamaterial devices that could be practically used in automotive ultrasonic radars, robot sonar systems, structural health monitoring and medical instrumentation and imaging applications. [ABSTRACT FROM AUTHOR]

Optimization of the composition of enzyme cocktail is an effective way to improve the hydrolytic efficiency and reduce the cost during enzymatic hydrolysis of lignocellulose. Herein, the optimal enzymes ratios of enzyme cocktails for efficient hydrolysis of corncobs with distinct pretreatments were quantitatively formulated. As the importance of pretreatment type on xylan extraction, the optimized cellulase/hemicellulase ratios for NaClO 2 , H 2 SO 4 and steam explosion treated corncob were 1:1.5, 1:0.15 and 1:0.75, respectively. Meanwhile, different requirements for types of cellulases are also determined: endoglucanase and cellobiohydrolase were key enzymes in the hydrolysis of NaClO 2 and H 2 SO 4 treated corncobs, respectively, while the synergy of three kinds of cellulases was preferred for steam-exploded corncob. Furthermore, based on the optimized cellulase/hemicellulase ratios, cellulases proportions for hydrolyzing the corncobs pretreated with distinctive methods were determined. Notably, by the enzymatic formulation strategy, 100% yields of glucose and xylose were obtained simultaneously from NaClO 2 treated corncob, which was up to 70.1% and 80.1% at high solid loading (20%), respectively. Without detoxification of hydrolysate, high isopropanol yield of 0.45 g/g (of dry matter) was achieved. Hence, this study demonstrated a low cost and high efficient conversion strategy for prospective high-value utilization of lignocellulose. • Three pretreatments for lignin and hemicellulose extraction were tested. • Key enzymes for hydrolyzing corncobs with distinct pretreatments were analyzed. • 100% glucose and xylose of sodium chlorite treated corncob were obtained. • Maximum corncob biomass conversion to biofuels was unlocked. [ABSTRACT FROM AUTHOR]

Magnetorheological elastomer (MRE) is a novel intelligent material, which shows excellent potential in vibration control applications. Previous researches have fully demonstrated that the magneto-induced shear storage modulus of MRE largely determines the vibration control effect. However, both existing theoretical and experimental ways to measure the magneto-induced shear storage modulus of MRE face their own shortage. Therefore, a novel physics-guided deep learning model is proposed to efficient predict the magneto-induced mechanical properties of MRE based on Magnetic Dipole theory and data-driven methods. A small database is built by collecting the magneto-induced shear storage modulus of MRE with different material ratios tested on a special shear rheometer. The proposed model trained with small training samples and its prediction results fit well with experimental values (average R2 of 0.99) which is superior to existing constitutive models. The training only takes 25 s, which significantly shortens the time compared to the experiment. Furthermore, the proposed model effectively predicts the magneto-induced storage modulus of MRE and has good generalization and superior transfer performance. [Display omitted] [ABSTRACT FROM AUTHOR]

The pulse force generated by the propeller excites the hull through the propulsion shafting system, which is the primary source of vibration and noise of ships. In order to control the transmission of longitudinal vibration of ship shafting, a multimodal dynamic vibration absorber (MDVA) with broadband vibration control performance is proposed. A magnetorheological elastomer (MRE) was prepared and used as an elastic element to construct a semi-active dynamic vibration absorber (SDVA), designed spiral flexible springs and embedded SDVA into the proposed MDVA. An equivalent propeller propulsion shaft system model was established, and its first three longitudinal vibrations were controlled based on the MDVA. Furthermore, the stiffness and damping of the MDVA were optimized by fixed point theory. A design scheme for the MDVA considering the changes in oil film stiffness of thrust bearings under different propeller speed conditions was proposed. The results indicate that the MDVA has excellent vibration transmission control performance at the first three natural frequencies. The proposed MDVA also has a broader frequency band for controlling vibration near first-order resonance than the traditional single degree of freedom DVA, which has excellent vibration control performance under variable speed conditions. [ABSTRACT FROM AUTHOR]

The geomorphologic and environmental evolution of the Loess Plateau is greatly affected by the strong fault activity, leading to the frequent occurrence of geological hazards, particularly the loess-mudstone landslide (LML). Thus, it is crucial to investigate the formation mechanism of such landslides in active fault zones. In this study, a field survey was conducted in the Weibei tableland of Baoji where the active fault zone is developed. To study the creep behavior of LML sliding zone soil, the triaxial creep tests of multi-stage loading under different water content, confining pressure, dry density, loess-mudstone binary structure (LMBS) contact surface angle, and thickness were carried out using the sliding zone soil samples (loess, mudstone, and LMBS samples) obtained from Wolongsi landslide in the study area as an example. Experimental results revealed that: (1) Water content has a significant weakening effect on the strength of LML sliding zone soil. The strength of the LMBS sample is extremely water-sensitive. The weakening effect of water on the long-term strength of LML sliding zone soil mainly manifested in promoting the elastoplastic deformation of loess and the viscoplastic deformation of mudstone. (2) The long-term strength of the LML slip zone soil increases linearly with the increase in confining pressure and increases exponentially with the dry density. (3) The degrading effect of the stratigraphic interface dip angle on the long-term slope strength is mainly reflected in the change in the weakening degree of water on the strength of the LML sliding zone. In addition, according to the test results, the traditional Nishihara model is improved by introducing nonlinear parameters, and a new constitutive equation describing LML sliding zone soil is established. The new constitutive model can accurately describe the creep curve's whole process especially sensitively identifying the accelerated creep stage. Finally, after conducting a field investigation and laboratory tests, the main hazard factors affecting the occurrence of the LML were analyzed in the presence of fault activity on the Weibei Plateau of Baoji, China, and its formation mechanism was revealed as well. [ABSTRACT FROM AUTHOR]

Abstract: High production cost is a major obstacle to the extensive use of microalgae biodiesel. To cut the cost and achieve higher biomass productivity, Chlorella minutissima UTEX2341 was cultured under photoheterotrophic conditions. With the carbon, nitrogen and phosphorus concentration of 26.37, 2.61 and 0.03gL−1 d−1 respectively, a maximum biomass productivity of 1.78gL−1 d−1 was obtained, which was 59 times more than that cultured under autotrophic condition. The lipid productivity reached 0.29gL−1 d−1, which was 11.9 times higher than the highest value reported by . The conversion rate of microalgae lipids to FAME was found to be elevated from 45.65% to 62.97% and the FAME productivity increased from 1.16 to 180.68mgL−1 d−1 after the optimization. 94% of the fatty acid of C. minutissima UTEX2341 was found to be composed of palmitic, oleic, linoleic and γ linoleic and the unsaturated fatty acids were the main parts (79.42%). [Copyright &y& Elsevier]

Abstract: Humic acids (HAs) play an important role in the global nitrogen cycle by influencing the distribution, bioavailability, and ultimate fate of organic nitrogen. Ammonium oxidation by autotrophic ammonia-oxidizing bacteria (AOB) is a key process in ecosystems and is limited, in part, by the availability of NH4 +. We evaluated the impact of HAs on soil AOB in microcosms by applying urea (1.0%, equal to 10 mg urea/g soil) with 0.1% bHA (biodegraded lignite humic acids, equal to 1 mg/g soil), 0.1% cHA (crude lignite humic acids) or no amendment. AOB population size, ammonium and nitrate concentrations were monitored for 12 weeks after urea and HA application. AOB densities (quantified by real-time PCR targeting the amoA) in the Urea treatments increased about ten-fold (the final abundance: 5.02 × 107 copies (g of dry soil)−1) after one week of incubation and decreased to the initial density after 12 weeks incubation; the population size of total bacteria (quantified by real-time PCR with a universal bacterial probe) decreased from 1.12 × 1010 to 2.59 × 109 copies (g of dry soil)−1 at week one and fluctuated back to the initial copy number at week 12. In the Urea + bHA and Urea + cHA treatments, the AOB densities were 4 and 6 times higher, respectively, than the initial density of approximately 5.07 × 106 copies (g of dry soil)−1 at week 1 and did not change much up to week 4; the total bacteria density changed little over time. The AOB and total bacteria density of the controls changed little during the 12 weeks of incubation. The microbial community composition of the Urea treatment, based on T-RFLP using CCA (canonical correspondence analysis) and pCCA (partial CCA) analysis, was clearly different from those of other treatments, and suggested that lignite HAs buffered the change in diversity and quantity of total bacteria caused by the application of urea to the soil. We hypothesize that HAs can inhibit the change in microbial community composition and numbers, as well as AOB population size by reducing the hydrolysis rate from urea to ammonium in soils amended with urea. [Copyright &y& Elsevier]

Abstract: In this study, the feasibility of bioflocculant extraction from backwashing sludge to reduce its production costs was investigated. Results showed that ultrasound and base treatment could significantly enhance bioflocculant extraction efficiency, however, flocculating activity was affected. It was observed that bioflocculants extracted from sludge of pH 11.0 had no flocculating activity. In contrast, bioflocculants extracted from sludge of pH 5.0, named as M-1, had good flocculating activity. To further study the flocculating activity of M-1, factors such as bioflocculant dosage, temperature and pH of the reaction solution were tested. The optimal conditions were 6.0mg/l bioflocculant dosage and pH 5.0, at a temperature of 10°C. Under these conditions, the flocculating rate of kaolin clay was 92.67%. The effectiveness of such bioflocculants in the decolorization of synthetically dyed wastewater was then examined. In flocculating methylene blue and fast blue in aqueous solutions, decolorization efficiency levels were 82.9% and 77.8%, respectively. [Copyright &y& Elsevier]

• Cd2+ inhibited the most of basic metabolism pathways except lipid metabolism. • Seven transcription factors with glutathionylated sites linked to TAG metabolism. • Transcription factors MYB, NF-YB and ABI5 regulated DGAT expression. • Triacylglycerol maintained lipid homeostasis by balancing fatty acids saturation. • Microalgae activated TAG synthesis by GSH then resisted the Cd stress together. Under ultra-high cadmium (Cd) stress, large amounts of glutathione are produced in Auxenochlorella protothecoides UTEX 2341, and the lipid content increases significantly. Glutathione is the best reductant that can effectively remove Cd, but the relationship between lipid accumulation and the cellular response to Cd stress has not been ascertained. Integrating analyses of the transcriptomes and lipidomes, the mechanism of lipid accumulation to Cd tolerance were studied from the perspectives of metabolism, transcriptional regulation and protein glutathionylation. Under Cd stress, basic metabolic pathways, such as purine metabolism, translation and pre-mRNA splicing process, were inhibited, while the lipid accumulation pathway was significantly activated. Further analysis revealed that the transcription factors (TFs) and genes related to lipid accumulation were also activated. Analysis of the TF interaction sites showed that ABI5, MYB_rel and NF-YB could further regulate the expression of diacylglycerol acyltransferase through glutathionylation/deglutathionylation, which led to increase of the triacylglycerol (TAG) content. Lipidomes analysis showed that TAG could help maintain lipid homeostasis by adjusting its saturation/unsaturation levels. This study for the first time indicated that glutathione could activate TAG synthesis in microalga A. protothecoides , leading to TAG accumulation and glutathione accumulation under Cd stress. Therefore, the accumulation of TAG and glutathione can confer resistance to high Cd stress. This study provided insights into a new operation mode of TAG accumulation under heavy metal stress. [Display omitted] [ABSTRACT FROM AUTHOR]

Raffinose family oligosaccharides (RFOs) negatively affect nutritional value of legume-derived food and feed. It has been challenging to develop a high performance α-galactosidase excelled on catalytic efficiency, thermostability, pH stability and protease-resistance that could efficiently hydrolyze RFOs. In this study, the first GH family 27 α-galactosidase gene from Irpex lacteus was cloned. The gene had an open reading frame of 1314 bp interrupted by 12 introns. The recombinant α-galactosidase expressed in Pichia pastoris (rILgalA) had an apparent molecular mass of 64 kDa and was highly N-glycosylated. rILgalA was maximally active at pH 4.8 and 70 °C. It was stable over a broad pH range of 3–11, retained 90% of its activity after incubation at 60 °C for 10 h and exhibited strong resistance to digestive proteases. Unlike many other α-galactosidases, rILgalA was hyperactive on RFOs. Its specific activities toward melibiose, raffinose and stachyose were 644, 755 and 833 U mg−1, respectively. The corresponding K cat / K m values were 120, 130 and 180 mM−1 s−1, which were the highest among reported α-galactosidases. rILgalA almost completely hydrolyzed raffinose and stachyose in soymilk at 60 °C in 30 min. These superior properties would make rILgalA an ideal remover of RFOs in food and feed industries. Unlabelled Image • α-Galactosidase gene from Irpex lacteus was cloned for the first time. • rILgalA expressed in P. pastoris was hyperactive on RFOs. • rILgalA possessed good thermal and pH stability as well as strong protease-resistance. • The rapidest enzymatic removal of RFOs from soymilk was achieved by rILgalA. [ABSTRACT FROM AUTHOR]

[Display omitted] • Distinct pretreated substrate can be used as inducer for specific enzyme production. • Formulation of cocktails with distinct components improved the hydrolysis efficiency. • 100% glucose and xylose of ultrafine grinding treated corn stover were obtained. In order to optimize the composition of enzyme cocktail for improving the hydrolytic efficiency of lignocellulose, different substrates were tested as inducers for producing lignocellulolytic enzymes by Trichoderma harzianum EM0925 in this study. As results, ultrafine grinding or steam explosion pretreated substrates can induce T. harzianum EM0925 to secret holo lignocellulolytic enzymes; acid treated substrate can induce cellobiohydrolase; while alkali or sodium chlorite treated substrates can induce β-xylosidase specifically. Furthermore, the combination of enzyme cocktails with different hydrolysis characteristics can further improve the hydrolysis efficiency, since 100% yields of glucose and xylose were obtained simultaneously from ultrafine grinding treated corn stover at low enzyme dosage (1.2 mg proteins/g substrate). This study for the first time demonstrated an effective solution that specific-pretreated substrates can be used as inducers for specific enzyme production by T. harzianum , which provided new idea and potential strategy for the construction of highly-efficient lignocellulolytic enzyme cocktails. [ABSTRACT FROM AUTHOR]

Airborne bacteria were measured when a dust storm passed Beijing in spring 2012 with a focus on cell concentration, viability and TSA- and R2A-cultured strain composition. The concentration varied at an order of 10 7 cells/m 3 with dust loading (demonstrated with PM 10 ) and they had a very close correlation ( R T 2 = 0.91, p < 0.01). At the time of highest PM 10 of 652 μg/m 3 , the bacterial concentration reached 1.4 × 10 8 cells/m 3 , which was larger than that before and after the dust event by one order. Bacterial viability, the ratio of number concentration of viable cells to total cells, was 32%–64% and smaller in the dust plume than that before the dust arrival. Bacterial strains from the culture ranged between 2.5 × 10 4 and 4.6 × 10 5 CFU/m 3 and no correlation with PM 10 was determined. Their composition was different before and after the dust arrival according to 16S rRNA gene sequences and strains belong to Actinomycetes and Firmicutes were the majority in the dust samples. [ABSTRACT FROM AUTHOR]

A finite element model for a composite T-joint structure under tensile loading has been established to simulate and analyze failure mechanisms, carrying capacities, in-plane and interlaminar damage behaviors based on the Tsai-Wu failure criterion and a cohesive zone model. Strains on the stress-concentration zone of the T-joint structure during loading were measured to validate the FEM model. The results showed that the simulated results had a good agreement with that of the measurements. The carrying capacity of the composite T-joint is mainly determined by failure modes, which can be changed by reducing fillet-filling ratio in the fillet of the T-joint and initiation and propagation paths of delamination cracks between the fillet and the L-ribs. The maximum tensile load of the T-joint calculated by FEM methods was 1854N, while the experimental value was 1862N. [ABSTRACT FROM AUTHOR]

Abstract: Bending properties and failure modes of carbon fiber composite egg and pyramidal honeycomb beams were studied and presented in this paper. Three point bending responses of both sandwich beams were tested. Face wrinkling, face crushing, core member crushing and debonding were considered, and theoretical relationships for predicting the failure load associated with each mode were presented under three point bending load. Failure mechanism maps were constructed to predict the failure of composite sandwich beams with pyramidal and egg honeycomb cores subjected to bending. Face wrinkling and core debonding have been investigated under three point bending and the maximum displacement was studied using analytical and experimental methods. The finite element method was employed to determine the ratio (maximum displacement/applied load) of sandwich beam with two different honeycomb cores. Comparisons between two kinds of honeycomb beams were also conducted. [Copyright &y& Elsevier]

Abstract: In this paper, the polyurethane foam filled pyramidal lattice core sandwich panel is fabricated in order to improve the energy absorption and low velocity impact resistance. Based on the compression tests, a synergistic effect that the foam filled sandwich panels have a greater load carrying capacity compared to the sum of the unfilled specimens and the filled polyurethane block is found. Moreover, the energy absorption efficiency of foam filled sandwich panels with higher relative density (2.58% and 3.17%) lattice cores is lower than that of the unfilled specimens when the compressive strain is small, while it exhibits superior when the compressive strain arrives at about 0.25, and the superiority enlarges as the strain increase. However, the energy absorption of foam filled sandwich panels owning lower relative density (1.83%) lattice cores is inferior to that of the unfilled specimens. During the low velocity impact tests, it is found that the contact duration between the impactor and the sandwich specimens is shorter and the impact peak load has a slight increase for the foam filled specimens. [Copyright &y& Elsevier]

Highlights: [•] Environmental factors were proved to be helpful to lipid accumulation. [•] NaCl, Fe3+ and nitrogen starvation together made lipid content increase to 2.5 times. [•] Both high and low temperature could promote lipid accumulation. [•] UTEX 2341 was proved to be a potential species for high-quality biodiesel production. [ABSTRACT FROM AUTHOR]

Abstract: A combined experimental and numerical study is conducted to assess the effects of impact energy, impact site and core density on the compression-after-impact (CAI) strength of pyramidal truss core sandwich structures. It is found that the severity of impact damage highly depends on the impact site. The CAI tests show that the local buckling occurs for both the un-impact specimens and the specimens impacted under lower energy, while debonding is observed for the specimens impacted under higher energy. In case of the specimens impacted on the middle point of the four adjacent nodes, only a crack appears in the impact-damaged facesheet, which propagates transversely across the facesheet. It is observed that the CAI strength of specimens impacted on the middle point of four adjacent nodes drop much more than that of specimens impacted on the node, and that the specimens with higher density cores have slightly lower normalized CAI strength reduction. Moreover, it is found that the CAI strength of specimens impacted on the node decreases with the impact energy increasing. In addition to experimental tests, the numerical simulation performs well in capturing the failure modes for impact-damaged specimens under compressive load. [Copyright &y& Elsevier]

Abstract: Many rice breeding programs have currently reached yield plateaus as a result of limited genetic variability in parental strains. Dongxiang common wild rice (Oryza rufipogon Griff.) is the progenitor of cultivated rice (Oryza sativa L.) and serves as an important gene pool for the genetic improvement of rice cultivars. In this study, heterotic loci (HLs) associated with six yield-related traits were identified in wild and cultivated rice and investigated using a set of 265 introgression lines (ILs) of O. rufipogon Griff. in the background of the Indica high-yielding cultivar Guichao 2 (O. sativa L.). Forty-two HLs were detected by a single point analysis of mid-parent heterosis values from test cross F1 offspring, and 30 (71.5%) of these HLs showed significantly positive effects, consistent with the superiority shown by the F1 test cross population in the six yield-related traits under study. Genetic mapping of hsp11, a locus responsible for the number of spikelets per panicle, confirmed the utility of these HLs. The results indicate that favorable HLs capable of improving agronomic traits are available. The identification of HLs between wild rice and cultivated rice could lead to a new strategy for the application of heterosis in rice breeding. [Copyright &y& Elsevier]

Abstract: A novel intracellular bioflocculant (named MBF-W6) produced by Chryseobacterium daeguense W6 cultured in low nutrition medium was investigated in this study. The effects of carbon source, nitrogen source, C/N ratio, initial pH, inoculum size, culture temperature and shaking speed on MBF-W6 production were studied. Chemical analysis showed that the purified MBF-W6 was mainly composed of 32.4% protein, 13.1% polysaccharide and 6.8% nucleic acid. Fourier-transform infrared (FTIR) spectroscopy indicated the presence of carboxyl, hydroxyl, and methoxyl groups. The elemental analysis of purified MBF-W6 revealed that the mass proportion of C, H, O, N and S was 40.92:6.53:44.01:8.53:1.01 (w/w) correspondingly. MBF-W6 had good flocculating rate in Kaolin suspension without any cation addition. The highest flocculating rate of 96.9% was achieved under the optimal conditions (bioflocculant dosage 1.2mgl−1, pH 5.6 and temperature 15°C). [Copyright &y& Elsevier]

Abstract: Programmed cell death (PCD) is a crucial process for plants during development and environmental stress. OsPDCD5, is an ortholog to mammalian programmed cell death 5 gene. Here we report that decreased expression of OsPDCD5 caused by antisense technology could induce pollen sterility in photoperiod-sensitive rice. The male sterility of transgenic plants is reversible, determined mainly by photoperiod. Transgenic plants are sterile under long-day photoperiod (≥13.5h sunlight) with postponed heading time, while they can restore fertility under short-day photoperiod (below 13h sunlight). Analysis of tissue sections of anthers displays the tapetum cells of the anther wall retard PCD process in transgenic plants under long-day photoperiod. The retarded PCD was also confirmed by DNA fragmentation. In F1 hybrids made from transgenic plants with antisense-OsPDCD5 and japonica rice varieties, lower transcript inhibition could restore fertility, under certain photoperiod and temperatures. The surprising discovery of the photosensitive male fertility suggested that by using specific photoperiods, the male sterility (PGMS) could be used for commercial production of hybrid rice using a two-line breeding system. The transgenic hybrid strategy was easy to apply, reduced costs and shortened the breeding period. It provides great advantages for commercial applications in rice and other crops. [Copyright &y& Elsevier]

Abstract: Conversion of acorn fringe extract into ellagic acid production by Aspergillus oryzae and Endomyces fibuliger were investigated. The results showed that ellagic acid production was maximized when co-fermentation of the two fungi was performed at 30°C and pH 5.0 with 5.7g/l of initial substrate concentration, which were close to the optimal values for both fungi to yield an appropriate consortium of hydrolytic enzymes. Meanwhile, it was found that the co-fermentation could compensate the deficiencies in the level of polyphenol oxidase activity from pure A. oryzae and the levels of ellagitannin acyl hydrolase and β-glucosidase activities from pure E. fibuliger, resulting in. 0.91g/l of biomass concentration containing 1.84g/l of ellagic acid. The research not only demonstrates that the co-fermentation is an effective approach to utilize forest byproduct for ellagic acid production, but also provides more evidences for understanding evolution of ellagic acid production with enzymes actions, which is important for process control of ellagic acid production in industrial application. [Copyright &y& Elsevier]

Abstract: Programmed cell death (PCD) is crucial for plants during development and stress survival. OsPDCD5, an ortholog to mammalian-programmed cell death 5, was previously cloned from rice (Oryza sativa, cv Zhenxian 97A), and its overexpression can induce PCD in transgenic rice. In the present study, immunoblotting analysis revealed that the OsPDCD5 protein was widely expressed in the tassel, leaf, leaf sheath, and different parts of the stem but not in the anther. RT-PCR analysis showed that OsPDCD5 was related to the senescence of leaf and root tissues as well as the development of stem tissues. Furthermore, OsPDCD5 was up-regulated by UV-B irradiation. Calcineurin B-like interacting protein kinase 23 (OsCIPK23), which is involved in the calcineurin B-like proteins (CLBs)/CBL-interacting protein kinases (CIPKs) signaling network, was identified as interacting with OsPDCD5 by yeast two-hybrid screening and subsequently confirmed by pull-down assay in vitro. Present findings may shed light on the investigation of the biochemical function of OsPDCD5 in rice. [Copyright &y& Elsevier]

The static/dynamic compressive performances of sandwich panels with density gradient lattice core were investigated by experimental and numerical methods. A three-layer stainless steel lattice sandwich panel was proposed, and the density gradient between core layers of the sandwich panels was achieved by varying the cross-sectional dimensions of truss bar of each layer. A large diameter Hopkinson pressure bar device was employed to carried out the dynamic impact experiment. The three-dimension finite element method was used to investigate the effects of gradient scheme of core layers and the impact velocity on the structural response. The results reveal that, there exists different failure mechanism between non-gradient lattice sandwich panels and gradient lattice sandwich panels, and the ABC gradient configuration is optimal due to its higher impact strength and better energy absorption capacity at a higher impact velocity which can buckle the truss bars of all layers of gradient lattice sandwich panel. [ABSTRACT FROM AUTHOR]

• Poor mechanical robustness still hinders water repellent coatings for application. • Natural weakness of nanoscale structures causes poor mechanical robustness. • Inverse infusion process creates much stronger micro/nano hybrid structures. • Newly synthesized epoxy enhances both water repellency and mechanical strength. • Water repellent coatings with comprehensive robustness in very harsh conditions. Poor mechanical durability still hinders artificial superhydrophobic coatings from practical application, although these coatings were created years ago and still attract wide research interest. Previous epoxy/nanoparticle works seem to encounter a dilemma: a delicate nanostructure and low surface energy without a proper and strong microstructure to provide protection and strength naturally leads to weak mechanical adhesion and poor wear robustness. Herein, we develop an inverse infusion process (IIP) to construct hierarchical structures via newly synthesized hydrophobic and tough epoxy resin as well as rationally selected alumina nanoparticles (NPs). The IIP process forms an uncured epoxy layer first on the substrate and a preliminary nanocomposite coating next using an air spraying method, after which the epoxy layer inversely infuses into the micro/nanostructure and constructs a tougher microstructure on the top as well as a continuous nanocomposite layer throughout the coating after curing. This results in superhydrophobic coatings on a substrate with excellent adhesion and mechanical robustness, and our coatings can tolerate 600 cycles of tape peeling tests (with 3 M high-tack tape), 20 m sandpaper abrasion (with a pressure of ~5 kPa and 80 grit sandpaper), 115 cycles of Taber abrasion (with 250 g load), and 600 g of sand impact from a height of 110 cm, which are the highest values achieved by superhydrophobic coatings to the best of our knowledge. Furthermore, our coatings sustained highly corrosive media, such as sodium hydroxide and hydrochloric acid solutions. A combination of the established IIP process and the rationally selected ingredients dramatically enhanced the mechanical durability of the superhydrophobic coatings, and these attractive materials may attract attention for self-cleaning, anti-icing, and anti-fouling applications in industry. [ABSTRACT FROM AUTHOR]