35 research outputs found
Optimizing medium for producing ethanol from industrial crop Jerusalem artichoke by one- step fermentation and recombinant Saccharomyces cerevisiae
In order to obtain a high ethanol yield from the Jerusalem artichoke raw extract and reduce the fermentation cost, we have engineered a new recombinant Saccharomyces cerevisiae strain that could produce ex-inulinase. The response surface methodology based on Plackett-Burman and Box-Behnken design was used to optimize the medium for the ethanol production from the Jerusalem artichoke raw extracts by the recombinant strain. In the first optimization step, Plackett-Burman design was employed to select significant factors, including concentrations of yeast extract, inoculum, and MgSO(4)7H(2)O. In the second step, the steepest ascent experiment was carried out to determine the center point with the three significant factors; the selected combinations were further optimized using the Box-Behnken design. The maximum ethanol production rate was predicted at 91.1g/l, which was based on a medium consisting of yeast extract 9.24g/l, inoculum 39.8ml/l, and MgSO(4)7H(2)O 0.45g/l. In the validating experiment, the ethanol fermentation rate reached 102.1g/l, closely matching the predicted rate.In order to obtain a high ethanol yield from the Jerusalem artichoke raw extract and reduce the fermentation cost, we have engineered a new recombinant Saccharomyces cerevisiae strain that could produce ex-inulinase. The response surface methodology based on Plackett-Burman and Box-Behnken design was used to optimize the medium for the ethanol production from the Jerusalem artichoke raw extracts by the recombinant strain. In the first optimization step, Plackett-Burman design was employed to select significant factors, including concentrations of yeast extract, inoculum, and MgSO(4)7H(2)O. In the second step, the steepest ascent experiment was carried out to determine the center point with the three significant factors; the selected combinations were further optimized using the Box-Behnken design. The maximum ethanol production rate was predicted at 91.1g/l, which was based on a medium consisting of yeast extract 9.24g/l, inoculum 39.8ml/l, and MgSO(4)7H(2)O 0.45g/l. In the validating experiment, the ethanol fermentation rate reached 102.1g/l, closely matching the predicted rate
Charge-dependent flow and the search for the chiral magnetic wave in Pb-Pb collisions at root s(NN)=2.76 TeV
Peer reviewe
Controlling system for smart hyper-spectral imaging array based on liquid-crystal Fabry-Perot device
A research for developing a kind of smart spectral imaging detection technique based on the electrically tunable liquid+crystal Fabry-Perot(LC-FP) structure is launched. It has some advantages, such as low cost, highly compact integration, perfuming wavelength selection without moving any micro-mirror of FP device, and the higher reliability and stability. The controlling system for hyper-spectral imaging array based on LC-FP device includes mainly a MSP430F5438 as its core. Considering the characteristics of LC-FP device, the controlling system can provide a driving signal of1-10 kHz and0-30Vrms for the device in a static driving mode. This paper introduces the hardware designing of the control system in detail. It presents an overall hardware solutions including:(1) the MSP430 controlling circuit, and(2) the operational amplifier circuit, and(3) the power supply circuit, and(4) the AD conversion circuit. The techniques for the realization of special high speed digital circuits, which is necessary for the PCB employed, is also discussed.?2011 SPIE
Evaluation of MLSR and PLSR for estimating soil element contents using visible/near-infrared spectroscopy in apple orchards on the Jiaodong peninsula
Conventional methods for soil element content determination based on laboratory analyses are costly and time-consuming. A soil reflectance spectrum is an alternative approach for soil element content estimation with the advantage of being rapid, non-destructive, and cost effective. Visible/near-infrared spectra (350 nm to 2500 nm) were measured from 105 soil samples originating from 30 apple orchards on the jiaodong peninsula. The Savitzky-Golay (FD-SG) technique for spectral data was implemented to reduce the signal noise. Logarithm of the reciprocal of reflectance (logR(-1)) and the first derivative transformation (DR) were used to accentuate the features and to prepare the data for use in quantitative estimation models. The SI (sum index), DI (difference index), PI (product index), RI (ratio index), and NDI (normalized difference index) were calculated to extract sensitive waveband combinations that are significantly related to soil element contents. Soil element contents were retrieved based on sensitive waveband combinations by multiple linear stepwise regression (MLSR) and partial least square (PLSR) models. The results showed that DR performed better than logR-1 in eliminating the interfering factors of soil particle size and spectral noise. The MLSR and PLSR calibration models based on PI performed better than those based on SI or DI did. The MLSR performed better than PLSR in estimating soil elemental content. The contents of total nitrogen (TN), arsenic (As), and mercury (Hg) could be estimated well using MLSR and PLSR calibration models developed with PI. The MLSR calibration-model developed with PI performed well in estimating available potassium (A-K) content. However, the contents of available phosphorus (A-P), ammonium nitrogen (NH4+-N), nitric nitrogen (NO3--N), and soil organic matter (SOM) could not be estimated using MLSR or PISR calibration models. These outcomes will provide the theoretical basis and technical support for estimations of soil element content using visible/near-infrared spectra. Although they were shown to be useful in apple orchards of the jiaodong peninsula, these models and methods should be further tested in soil samples from other regions and countries to prove their validity. (C) 2015 Elsevier B.V. All rights reserved
Biochar had effects on phosphorus sorption and desorption in three soils with differing acidity
Changes in soil phosphorus (P) availability after biochar application have been reported in a number of glasshouse and field trials. However, the mechanisms underlying these changes remain poorly understood. This study evaluated the effects of four biochar application rates (0, 1%, 5%, and 10%, w/w) on P sorption and desorption in three soil types with different levels of acidity. Results showed that the effects of biochar application on P sorption were highly influenced by soil acidity. As the rate of biochar application increased, P sorption increased in the acidic soil but slightly decreased in the alkaline soil. Desorbed P significantly increased at all levels of biochar application in the studied soils. Inorganic P fractionation revealed that biochar addition sharply increased the Ca-bounded P and slightly enhanced the Al-retained P. However, biochar addition decreased the Fe-bounded P. These changes suggest that the increase in P sorption with biochar addition is attributed to Ca-induced P sorption or precipitation and is less affected by Fe and Al oxides. Biochar application is found to have altered P availability by changing the P sorption and desorption capacities of the soils, and these biochar effects were dependent on soil acidity, which have important implications for improving soil productivity on large scale. (C) 2013 Elsevier B. V. All rights reserved
Direct production of bioethanol from Jerusalem artichoke inulin by gene-engineering Saccharomyces cerevisiae 6525 with exoinulinase gene
Jerusalem artichoke (Helianthus tuberosus L.), an important crop, containing over 50% inulin in its tubers on a dry weight basis is an agricultural and industrial crop with a great potential for production of ethanol and industrial products. Inulin is a good substrate for bioethanol production. Saccharomyces cerevisiae 6525 can produce high concentrations of ethanol, but it cannot synthesize inulinase. In this study, a new integration vector carrying inuA1 gene encoding exoinulinase was constructed and transformed into 18SrDNA site of industrial strain S. cerevisiae 6525. The obtained transformant, BR8, produced 1.1UmL(-1) inulinase activity within 72h and the dry cell weight reached 12.3gL(-1) within 48h. In a small-scale fermentation, BR8 produced 9.5% (v/v) ethanol, with a productivity rate of 0.385g ethanol per gram inulin, while wild-type S. cerevisiae 6525 produced only 3.3% (v/v) ethanol in the same conditions. In a 5-L fermentation, BR8 produced 14.0% (v/v) ethanol in fermentation medium containing inulin and 1% (w/v) (NH4)(2)SO4. The engineered S. cerevisiae 6525 carrying inuA1 converted pure nonhydrolyzed inulin directly into high concentrations of ethanol.Jerusalem artichoke (Helianthus tuberosus L.), an important crop, containing over 50% inulin in its tubers on a dry weight basis is an agricultural and industrial crop with a great potential for production of ethanol and industrial products. Inulin is a good substrate for bioethanol production. Saccharomyces cerevisiae 6525 can produce high concentrations of ethanol, but it cannot synthesize inulinase. In this study, a new integration vector carrying inuA1 gene encoding exoinulinase was constructed and transformed into 18SrDNA site of industrial strain S. cerevisiae 6525. The obtained transformant, BR8, produced 1.1UmL(-1) inulinase activity within 72h and the dry cell weight reached 12.3gL(-1) within 48h. In a small-scale fermentation, BR8 produced 9.5% (v/v) ethanol, with a productivity rate of 0.385g ethanol per gram inulin, while wild-type S. cerevisiae 6525 produced only 3.3% (v/v) ethanol in the same conditions. In a 5-L fermentation, BR8 produced 14.0% (v/v) ethanol in fermentation medium containing inulin and 1% (w/v) (NH4)(2)SO4. The engineered S. cerevisiae 6525 carrying inuA1 converted pure nonhydrolyzed inulin directly into high concentrations of ethanol
Ecological water demand of regional vegetation: The example of the 2010 severe drought in Southwest China
To determine the cause of the severe drought that hit five provinces (autonomous regions, municipalities) of Southwest China in 2010, the ecological water demand (EWD) of regional vegetation was explored. The key scientific question was whether the plantation of Eucalyptus and Hevea trees in this area could have led to the breaking of the regional EWD balance, thereby causing a regional drought. Therefore, major research progress and trends related to EWD of vegetation, such as characterization of vegetation water consumption from transpiration and eco-hydrological effects, were explored. Theories, methods, and practices regarding EWD of vegetation, and the correlation between regional vegetation types and droughts were evaluated. Finally, suggestions were made for specific scientific research on temporal and spatial evolution of typical artificial vegetation in Southwest China and on the relationship between EWD from regional vegetation and droughts. Thus, future research should include the following three aspects: (i) historical evolution and distribution pattern of regional artificial vegetation; (ii) water consumption from transpiration, water saving for drought prevention, and water and soil conservation of regional artificial vegetation; and (iii) the relationship between EWD of regional artificial vegetation and regional droughts. The proposed research focus is expected to provide a scientific basis for identifying the causes of regional droughts and the reasonable allocation of water resources. In addition, it will be of great importance in guiding restoration and reconstruction of regional artificial vegetation.To determine the cause of the severe drought that hit five provinces (autonomous regions, municipalities) of Southwest China in 2010, the ecological water demand (EWD) of regional vegetation was explored. The key scientific question was whether the plantation of Eucalyptus and Hevea trees in this area could have led to the breaking of the regional EWD balance, thereby causing a regional drought. Therefore, major research progress and trends related to EWD of vegetation, such as characterization of vegetation water consumption from transpiration and eco-hydrological effects, were explored. Theories, methods, and practices regarding EWD of vegetation, and the correlation between regional vegetation types and droughts were evaluated. Finally, suggestions were made for specific scientific research on temporal and spatial evolution of typical artificial vegetation in Southwest China and on the relationship between EWD from regional vegetation and droughts. Thus, future research should include the following three aspects: (i) historical evolution and distribution pattern of regional artificial vegetation; (ii) water consumption from transpiration, water saving for drought prevention, and water and soil conservation of regional artificial vegetation; and (iii) the relationship between EWD of regional artificial vegetation and regional droughts. The proposed research focus is expected to provide a scientific basis for identifying the causes of regional droughts and the reasonable allocation of water resources. In addition, it will be of great importance in guiding restoration and reconstruction of regional artificial vegetation
Effects of salt stress on eco-physiological characteristics in Robinia pseudoacacia based on salt-soil rhizosphere
Robinia pseudoacacia is the main arbor species in the coastal saline-alkali area of the Yellow River Delta. Because most studies focus on the aboveground parts, detailed information regarding root functioning under salinity is scare. Root traits of seedlings of R. pseudoacacia including morphological, physiological and growth properties under four salinity levels (CK, 1 parts per thousand, 3 parts per thousand and 5 parts per thousand NaCl) were studied by the pot experiments to better understand their functions and relationships with the shoots. The results showed that seedling biomass decreased by the reduction of root, stem and leaf biomass with the increase of salinity levels. With increasing salinity levels, total root length (TRL) and total root surface area (TRSA) decreased, whereas specific root length (SRL) and specific root area (SRA) increased. Salt stress decreased root activity (RA) and the maximum net photosynthetic rate (Amax) and increased the water saturation deficit (WSD) significantly in the body. Correlation analyses showed significantly correlations between root morphological and physiologic-al parameters and seedling biomass and shoot physiological indexes. R. pseudoacacia seedlings could adapt to 1% salinity by regulating the root morphology and physiology, but failed in 5%. salinity. How to adjust the water status in the body with decreasing water uptake by roots was an important way for R. pseudoacctcict seedlings to adapt to the salt stress. (C) 2016 Published by Elsevier B.V
Screening for and Identification of an Anti-clam Vibrio Marine Bacterium from an Aquaculture Pond in the Yellow Sea
The identification and use of probiotic bacterial stains is a practical approach to protect clams grown in aquaculture farms from disease. The inhibition of the pathogenic bacterium Vibrio alginolyticus was used as a trait to select a candidate probiotic bacterial strain in this study. An ideal bacterial strain, SW-1, was isolated from seawater from a clam farm. The selected isolate SW-1 was identified based on its physiological, morphological, and biochemical characteristics and its 16S rDNA sequence. The experiments showed that strain SW-1 had a high similarity to Pseudoalteromonas piscicida and could inhibit the growth of V. alginolyticus (V.-MP-1). SW-1 also improved the survival of clams following challenge with the pathogenic V.-MP-1. The mortality of clams was 100% after infection with 10(8) CFU/mL of V. alginolyticus, whereas mortality was only 11% when clams were infected with 10(8) CFU/mL of V.-MP1 while simultaneously exposed to the same concentration of Pseudoalteromonas SW-1, indicating that Pseudoalteromonas SW-1 could be used as a probiotic to protect farmed clams, and thus reduce the effects of antibiotics on aquatic environment