How cell wall complexity influences saccharification efficiency in Miscanthus sinensis

DOE PAGES

De Souza, Amanda P.; Kamei, Claire L. Alvim; Torres, Andres F.; ...

2015-04-23

The production of bioenergy from grasses has been developing quickly during the last decade, with Miscanthus being among the most important choices for production of bioethanol. However, one of the key barriers to producing bioethanol is the lack of information about cell wall structure. Cell walls are thought to display compositional differences that lead to emergence of a very high level of complexity, resulting in great diversity in cell wall architectures. In this work, a set of different techniques was used to access the complexity of cell walls of different genotypes of Miscanthus sinensis in order to understand how theymore » interfere with saccharification efficiency. Three genotypes of M. sinensis displaying different patterns of correlation between lignin content and saccharification efficiency were subjected to cell wall analysis by quantitative/qualitative analytical techniques such as monosaccharide composition, oligosaccharide profiling, and glycome profiling. When saccharification efficiency was correlated negatively with lignin, the structural features of arabinoxylan and xyloglucan were found to contribute positively to hydrolysis. In the absence of such correlation, different types of pectins, and some mannans contributed to saccharification efficiency. In conclusion, different genotypes of M. sinensis were shown to display distinct interactions among their cell wall components, which seem to influence cell wall hydrolysis.« less

Engineering the cell wall by reducing de-methyl-esterified homogalacturonan improves saccharification of plant tissues for bioconversion.

PubMed

Lionetti, Vincenzo; Francocci, Fedra; Ferrari, Simone; Volpi, Chiara; Bellincampi, Daniela; Galletti, Roberta; D'Ovidio, Renato; De Lorenzo, Giulia; Cervone, Felice

2010-01-12

Plant cell walls represent an abundant, renewable source of biofuel and other useful products. The major bottleneck for the industrial scale-up of their conversion to simple sugars (saccharification), to be subsequently converted by microorganisms into ethanol or other products, is their recalcitrance to enzymatic saccharification. We investigated whether the structure of pectin that embeds the cellulose-hemicellulose network affects the exposure of cellulose to enzymes and consequently the process of saccharification. Reduction of de-methyl-esterified homogalacturonan (HGA) in Arabidopsis plants through the expression of a fungal polygalacturonase (PG) or an inhibitor of pectin methylesterase (PMEI) increased the efficiency of enzymatic saccharification. The improved enzymatic saccharification efficiency observed in transformed plants could also reduce the need for acid pretreatment. Similar results were obtained in PG-expressing tobacco plants and in PMEI-expressing wheat plants, indicating that reduction of de-methyl-esterified HGA may be used in crop species to facilitate the process of biomass saccharification.

Saccharification of woody biomass using glycoside hydrolases from Stereum hirsutum.

PubMed

Jeya, Marimuthu; Kalyani, Dayanand; Dhiman, Saurabh Sudha; Kim, Hoon; Woo, Seongmin; Kim, Dongwook; Lee, Jung-Kul

2012-08-01

Enzymatic saccharification of woody biomasses was performed using glycoside hydrolases from Stereum hirsutum, a newly isolated fungal strain found to secrete efficient glycoside hydrolases. The strain showed the highest β-glucosidase, cellobiohydrolase, endoglucanase, endoxylanase, laccase, and filter paper activity of 10.3, 1.7, 10.3, 29.9, 0.12, and 0.58 U/ml, respectively. Among the various biomasses tested for saccharification, pine biomass produced maximum reducing sugar. Response surface methodology was used to optimize the hydrolysis of pine biomass to achieve the highest level of sugars. The parameters including enzyme, substrate concentration, temperature and pH were found to be critical for the conversion of pine biomass into sugars. Maximum saccharification of 49.7% (435 mg/g-substrate) was obtained after 96 h of hydrolysis. A close agreement between the experimental results and the model predictions was achieved. S. hirsutum could be a good choice for the production of reducing sugars from cellulosic biomasses. Copyright © 2012 Elsevier Ltd. All rights reserved.

A Weibull statistics-based lignocellulose saccharification model and a built-in parameter accurately predict lignocellulose hydrolysis performance.

PubMed

Wang, Mingyu; Han, Lijuan; Liu, Shasha; Zhao, Xuebing; Yang, Jinghua; Loh, Soh Kheang; Sun, Xiaomin; Zhang, Chenxi; Fang, Xu

2015-09-01

Renewable energy from lignocellulosic biomass has been deemed an alternative to depleting fossil fuels. In order to improve this technology, we aim to develop robust mathematical models for the enzymatic lignocellulose degradation process. By analyzing 96 groups of previously published and newly obtained lignocellulose saccharification results and fitting them to Weibull distribution, we discovered Weibull statistics can accurately predict lignocellulose saccharification data, regardless of the type of substrates, enzymes and saccharification conditions. A mathematical model for enzymatic lignocellulose degradation was subsequently constructed based on Weibull statistics. Further analysis of the mathematical structure of the model and experimental saccharification data showed the significance of the two parameters in this model. In particular, the λ value, defined the characteristic time, represents the overall performance of the saccharification system. This suggestion was further supported by statistical analysis of experimental saccharification data and analysis of the glucose production levels when λ and n values change. In conclusion, the constructed Weibull statistics-based model can accurately predict lignocellulose hydrolysis behavior and we can use the λ parameter to assess the overall performance of enzymatic lignocellulose degradation. Advantages and potential applications of the model and the λ value in saccharification performance assessment were discussed. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Isolation, screening, and identification of potential cellulolytic and xylanolytic producers for biodegradation of untreated oil palm trunk and its application in saccharification of lemongrass leaves.

PubMed

Ang, S K; Yahya, Adibah; Abd Aziz, Suraini; Md Salleh, Madihah

2015-01-01

This study presents the isolation and screening of fungi with excellent ability to degrade untreated oil palm trunk (OPT) in a solid-state fermentation system (SSF). Qualitative assay of cellulases and xylanase indicates notable secretion of both enzymes by 12 fungal strains from a laboratory collection and 5 strains isolated from a contaminated wooden board. High production of these enzymes was subsequently quantified in OPT in SSF. Aspergillus fumigates SK1 isolated from cow dung gives the highest xylanolytic activity (648.448 U g(-1)), generally high cellulolytic activities (CMCase: 48.006, FPase: 6.860, beta-glucosidase: 16.328 U g(-1)) and moderate lignin peroxidase activity (4.820 U/g), and highest xylanolytic activity. The xylanase encoding gene of Aspergillus fumigates SK1 was screened using polymerase chain reaction by a pair of degenerate primers. Through multiple alignment of the SK1 strain's xylanase nucleotide sequences with other published xylanases, it was confirmed that the gene belonged to the xylanase glycoside hydrolase family 11 (GH11) with a protein size of 24.49 kD. Saccharification of lemongrass leaves using crude cellulases and xylanase gives the maximum reducing sugars production of 6.84 g/L with glucose as the major end product and traces of phenylpropanic compounds (vanillic acid, p-coumaric acid, and ferulic acid).

Enhanced Inulin Saccharification by Self-Produced Inulinase from a Newly Isolated Penicillium sp. and its Application in D-Lactic Acid Production.

PubMed

Zheng, Zhaojuan; Xu, Qianqian; Liu, Peng; Zhou, Fan; Ouyang, Jia

2018-03-10

In order to find an alternative for commercial inulinase, a strain XL01 identified as Penicillium sp. was screened for inulinase production. The broth after cultivated was centrifuged, filtered, and used as crude enzyme for the following saccharification. At pH 5.0 and 50 °C, the crude enzyme released 84.9 g/L fructose and 20.7 g/L glucose from 120 g/L inulin in 72 h. In addition, simultaneous saccharification and fermentation of chicory flour for D-lactic acid production was carried out using the self-produced crude inulinase and Lactobacillus bulgaricus CGMCC 1.6970. A high D-lactic acid titer and productivity of 122.0 g/L and 1.69 g/(L h) was achieved from 120 g/L chicory flour in 72 h. The simplicity for inulinase production and the high efficiency for D-lactic acid fermentation provide a perspective and profitable industrial biotechnology for utilization of the inulin-rich biomass.

Enhancement of enzymatic saccharification of Eucalyptus globulus: steam explosion versus steam treatment.

PubMed

Martin-Sampedro, Raquel; Revilla, Esteban; Villar, Juan C; Eugenio, Maria E

2014-09-01

Steam explosion and steam pre-treatment have proved capable of enhancing enzymatic saccharification of lignocellulosic materials. However, until now, these methods had not been compared under the same operational conditions and using the same raw material. Both pre-treatments lead to increased yields in the saccharification of Eucalyptus globulus; but results have been better with steam pre-treatments, despite the more accessible surface of exploded samples. The reason for this finding could be enzymatic inhibition: steam explosion causes a more extensive extraction of hemicelluloses and releases a greater amount of degradation products which can inhibit enzymatic action. Enzymatic inhibition is also dependent on the amount and chemical structure of lignin, which was also a contributing factor to the lower enzymatic yields obtained with the most severe pre-treatment. Thus, the highest yields (46.7% glucose and 73.4% xylose yields) were obtained after two cycle of steam treatment, of 5 and 3 min, at 183°C. Copyright © 2014 Elsevier Ltd. All rights reserved.

Elucidation of Factors Effecting Enzymatic Saccharification using Transgenic Hardwoods

NASA Astrophysics Data System (ADS)

Min, Douyong

Three groups of transgenic wood samples were used as starting materials to elucidate the recalcitrance of enzymatic saccharification with/without pretreatments. The first group of transgenic wood samples is low lignin P. trichocarpa. The second group is low xylan P. trichocarpa. The third one is 12 hybrid poplars which have different levels of S/V ratio and lignin content. Four pretreatments were carried out in this research including dilute sulfuric acid, green liquor, auto hydrolysis and ozone delignification. The behavior among pretreatments as a function of removal of lignin appears to be different. Lignin is the major factor of recalcitrance of the lignocellulosic material to ethanol conversion process. Xylan also plays key role in this process. In addition, the crude milled wood lignin was isolated from these three groups of transgenic samples. Lignin carbohydrate complexes was characterized by 1H-13C HMQC and 13C NMR. Thus the effect of LCCs on enzymatic saccharification was elucidated. High S/V ratio propels the lignin removal during pretreatments however; high S/V ratio retards the enzymatic saccharification on the lignocellulosic material without pretreatments. The level of LCCs linkages accounts for additional recalcitrance of the lignocellulosic material to ethanol conversion process. The amount of LCCs linkages is affected by xylan content, lignin content and S/V ratio.

Lignosulfonate and elevated pH can enhance enzymatic saccharification of lignocelluloses

PubMed Central

2013-01-01

Background Nonspecific (nonproductive) binding (adsorption) of cellulase by lignin has been identified as a key barrier to reduce cellulase loading for economical sugar and biofuel production from lignocellulosic biomass. Sulfite Pretreatment to Overcome Recalcitrance of Lignocelluloses (SPORL) is a relatively new process, but demonstrated robust performance for sugar and biofuel production from woody biomass especially softwoods in terms of yields and energy efficiencies. This study demonstrated the role of lignin sulfonation in enhancing enzymatic saccharification of lignocelluloses – lignosulfonate from SPORL can improve enzymatic hydrolysis of lignocelluloses, contrary to the conventional belief that lignin inhibits enzymatic hydrolysis due to nonspecific binding of cellulase. Results The study found that lignosulfonate from SPORL pretreatment and from a commercial source inhibits enzymatic hydrolysis of pure cellulosic substrates at low concentrations due to nonspecific binding of cellulase. Surprisingly, the reduction in enzymatic saccharification efficiency of a lignocellulosic substrate was fully recovered as the concentrations of these two lignosulfonates increased. We hypothesize that lignosulfonate serves as a surfactant to enhance enzymatic hydrolysis at higher concentrations and that this enhancement offsets its inhibitive effect from nonspecific binding of cellulase, when lignosulfonate is applied to lignocellulosic solid substrates. Lignosulfonate can block nonspecific binding of cellulase by bound lignin on the solid substrates, in the same manner as a nonionic surfactant, to significantly enhance enzymatic saccharification. This enhancement is linearly proportional to the amount of lignosulfonate applied which is very important to practical applications. For a SPORL-pretreated lodgepole pine solid, 90% cellulose saccharification was achieved at cellulase loading of 13 FPU/g glucan with the application of its corresponding pretreatment hydrolysate

The interdependence between screening methods and screening libraries.

PubMed

Shelat, Anang A; Guy, R Kiplin

2007-06-01

The most common methods for discovery of chemical compounds capable of manipulating biological function involves some form of screening. The success of such screens is highly dependent on the chemical materials - commonly referred to as libraries - that are assayed. Classic methods for the design of screening libraries have depended on knowledge of target structure and relevant pharmacophores for target focus, and on simple count-based measures to assess other properties. The recent proliferation of two novel screening paradigms, structure-based screening and high-content screening, prompts a profound rethink about the ideal composition of small-molecule screening libraries. We suggest that currently utilized libraries are not optimal for addressing new targets by high-throughput screening, or complex phenotypes by high-content screening.

Enzymatic Saccharification of Lignocelluloses Should be Conducted at Elevated pH 5.2-6.2

Treesearch

T.Q. Lan; Hongming Lou; J.Y. Zhu

2013-01-01

This study revealed that cellulose enzymatic saccharification response curves of lignocellulosic substrates were very different from those of pure cellulosic substrates in terms of optimal pH and pH operating window. The maximal enzymatic cellulose saccharification of lignocellulosic substrates occurs at substrate suspension

Enzymatic saccharification of liquid hot water and dilute sulfuric acid pretreated oil palm empty fruit bunch and sugarcane bagasse

NASA Astrophysics Data System (ADS)

Risanto, L.; Fitria; Fajriutami, T.; Hermiati, E.

2018-03-01

Oil palm empty fruit bunch (OPEFB) and sugarcane bagasse (SB) are potential feedstocks for the production of bioethanol. In this study OPEFB and SB were pretreated by liquid hot water and dilute sulfuric acid (3% H2SO4), and continued with enzymatic saccharification. Heating treatment for both methods was conducted in an autoclave at 121 °C for 1 hr. The saccharification was performed up to 72 hours with cellulase enzyme loading of 10, 20, and 30 FPU per g biomass. Results showed that OPEFB and SB pretreated with H2SO4 produced higher reducing sugars than those pretreated by liquid hot water. Higher enzyme loading also resulted in higher reducing sugars. Reducing sugars obtained from enzymatic saccharification of OPEFB were higher than those obtained from SB. The highest total reducing sugars (50.48 g/100 g biomass) was obtained from OPEFB pretreated with 3% H2SO4 at enzyme loading of 30 FPU per g biomass.

Low melting point pyridinium ionic liquid pretreatment for enhancing enzymatic saccharification of cellulosic biomass.

PubMed

Uju; Nakamoto, Aya; Shoda, Yasuhiro; Goto, Masahiro; Tokuhara, Wataru; Noritake, Yoshiyuki; Katahira, Satoshi; Ishida, Nobuhiro; Ogino, Chiaki; Kamiya, Noriho

2013-05-01

The potential of 1-hexylpyridinium chloride ([Hpy][Cl]), to pretreat cellulosic feedstocks was investigated using microcrystalline cellulose (Avicel) and Bagasse at 80 °C or 100 °C. Short [Hpy][Cl] pretreatments, <30 min, at lower temperature accelerate subsequent enzymatic saccharification of Avicel. Over 95% conversion of pretreated Avicel to glucose was attained after 24h enzymatic saccharification under optimal conditions, whereas regenerated Bagasse showed 1-3-fold higher conversion than untreated biomass. FT-IR analysis of both Avicel and Bagasse samples pretreated with [Hpy][Cl] or 1-ethyl-3-methyimidazolium acetate ([Emim][OAc]) revealed that these ionic liquids behaved differently during pretreatment. [Hpy][Cl] pretreatment for an extended duration (180 min) released mono- and disaccharides without using cellulase enzymes, suggesting [Hpy][Cl] has capability for direct saccharification of cellulosic feedstocks. On the basis of the results obtained, [Hpy][Cl] pretreatment enhanced initial reaction rates in enzymatic saccharification by either crystalline polymorphic alteration of cellulose or partial degradation of the crystalline cellulosic fraction in biomass. Copyright © 2012 Elsevier Ltd. All rights reserved.

Chemical characteristics and enzymatic saccharification of lignocellulosic biomass treated using high-temperature saturated steam: comparison of softwood and hardwood.

PubMed

Asada, Chikako; Sasaki, Chizuru; Hirano, Takeshi; Nakamura, Yoshitoshi

2015-04-01

This study investigated the effect of high-temperature saturated steam treatments on the chemical characteristics and enzymatic saccharification of softwood and hardwood. The weight loss and chemical modification of cedar and beech wood pieces treated at 25, 35, and 45 atm for 5 min were determined. Fourier transform infrared and X-ray diffraction analyses indicated that solubilization and removal of hemicellulose and lignin occurred by the steam treatment. The milling treatment of steam-treated wood enhanced its enzymatic saccharification. Maximum enzymatic saccharification (i.e., 94% saccharification rate of cellulose) was obtained using steam-treated beech at 35 atm for 5 min followed by milling treatment for 1 min. However, the necessity of the milling treatment for efficient enzymatic saccharification is dependent on the wood species. Copyright © 2015 Elsevier Ltd. All rights reserved.

Saccharification of sunflower stalks using lignocellulases from a fungal consortium comprising Pholiota adiposa and Armillaria gemina.

PubMed

Ramachandran, Priyadharshini; Kim, Tae-Su; Dhiman, Saurabh Sudha; Li, Jinglin; Park, Ji-Hyun; Choi, Joon-Ho; Kim, Jae Young; Kim, Dongwook; Lee, Jung-Kul

2015-09-01

Lignocellulases from Armillaria gemina and Pholiota adiposa are efficient in hydrolyzing aspen and poplar biomass, respectively. In the present study, lignocellulosic enzymes obtained from a fungal consortium comprising P. adiposa and A. gemina were used for the saccharification of sunflower stalks. Sunflower stalks were thermochemically pretreated using 2 % NaOH at 50 °C for 24 h. The saccharification process parameters including substrate concentration, enzyme loading, pH, and temperature were optimized using response surface methodology to improve the saccharification yield. The highest enzymatic hydrolysis (84.3 %) was obtained using the following conditions: enzyme loading 10 FPU/g-substrate, substrate 5.5 %, temperature 50 °C, and pH 4.5. The hydrolysis yield obtained using the enzymes from the fungal consortium was equivalent to that obtained using a mixture of commercial enzymes Celluclast and Novozyme β-glucosidase. Addition of up to 500 ppm of heavy metal ions (As, Cu, Fe, Mn, Ni, Pb, and Zn) during saccharification did not significantly affect the saccharification yield. Thus, the biomass grown for phytoremediation of heavy metals can be used for the production of reducing sugars followed by ethanol fermentation.

Microwave-Assisted Alkali Pre-Treatment, Densification and Enzymatic Saccharification of Canola Straw and Oat Hull

PubMed Central

Agu, Obiora S.; Tabil, Lope G.; Dumonceaux, Tim

2017-01-01

The effects of microwave-assisted alkali pre-treatment on pellets’ characteristics and enzymatic saccharification for bioethanol production using lignocellulosic biomass of canola straw and oat hull were investigated. The ground canola straw and oat hull were immersed in distilled water, sodium hydroxide and potassium hydroxide solutions at two concentrations (0.75% and 1.5% w/v) and exposed to microwave radiation at power level 713 W and three residence times (6, 12 and 18 min). Bulk and particle densities of ground biomass samples were determined. Alkaline-microwave pre-treated and untreated samples were subjected to single pelleting test in an Instron universal machine, pre-set to a load of 4000 N. The measured parameters, pellet density, tensile strength and dimensional stability were evaluated and the results showed that the microwave-assisted alkali pre-treated pellets had a significantly higher density and tensile strength compared to samples that were untreated or pre-treated by microwave alone. The chemical composition analysis showed that microwave-assisted alkali pre-treatment was able to disrupt and break down the lignocellulosic structure of the samples, creating an area of cellulose accessible to cellulase reactivity. The best enzymatic saccharification results gave a high glucose yield of 110.05 mg/g dry sample for canola straw ground in a 1.6 mm screen hammer mill and pre-treated with 1.5% NaOH for 18 min, and a 99.10 mg/g dry sample for oat hull ground in a 1.6 mm screen hammer mill and pre-treated with 0.75% NaOH for 18 min microwave-assisted alkali pre-treatments. The effects of pre-treatment results were supported by SEM analysis. Overall, it was found that microwave-assisted alkali pre-treatment of canola straw and oat hull at a short residence time enhanced glucose yield. PMID:28952504

Microwave-Assisted Alkali Pre-Treatment, Densification and Enzymatic Saccharification of Canola Straw and Oat Hull.

PubMed

Agu, Obiora S; Tabil, Lope G; Dumonceaux, Tim

2017-03-26

The effects of microwave-assisted alkali pre-treatment on pellets' characteristics and enzymatic saccharification for bioethanol production using lignocellulosic biomass of canola straw and oat hull were investigated. The ground canola straw and oat hull were immersed in distilled water, sodium hydroxide and potassium hydroxide solutions at two concentrations (0.75% and 1.5% w/v) and exposed to microwave radiation at power level 713 W and three residence times (6, 12 and 18 min). Bulk and particle densities of ground biomass samples were determined. Alkaline-microwave pre-treated and untreated samples were subjected to single pelleting test in an Instron universal machine, pre-set to a load of 4000 N. The measured parameters, pellet density, tensile strength and dimensional stability were evaluated and the results showed that the microwave-assisted alkali pre-treated pellets had a significantly higher density and tensile strength compared to samples that were untreated or pre-treated by microwave alone. The chemical composition analysis showed that microwave-assisted alkali pre-treatment was able to disrupt and break down the lignocellulosic structure of the samples, creating an area of cellulose accessible to cellulase reactivity. The best enzymatic saccharification results gave a high glucose yield of 110.05 mg/g dry sample for canola straw ground in a 1.6 mm screen hammer mill and pre-treated with 1.5% NaOH for 18 min, and a 99.10 mg/g dry sample for oat hull ground in a 1.6 mm screen hammer mill and pre-treated with 0.75% NaOH for 18 min microwave-assisted alkali pre-treatments. The effects of pre-treatment results were supported by SEM analysis. Overall, it was found that microwave-assisted alkali pre-treatment of canola straw and oat hull at a short residence time enhanced glucose yield.

Selection of thermotolerant yeasts for simultaneous saccharification and fermentation (SSF) of cellulose to ethanol.

PubMed

Ballesteros, I; Ballesteros, M; Cabañas, A; Carrasco, J; Martín, C; Negro, M J; Saez, F; Saez, R

1991-01-01

A total of 27 yeast strains belonging to the groups Candida, Saccharomyces, and Kluyveromyces were screened for their ability to grow and ferment glucose at temperatures ranging 32-45 degrees C. K. marxianus and K. fragilis were found to be the best ethanol producing organisms at the higher temperature tested and, so, were selected for subsequent simultaneous saccharification and fermentation (SSF) studies. SSF experiments were performed at 42 and 45 degrees C, utilizing Solkafloc (10%) as cellulose substrate and a cellulase loading of 15 FPU/g substrate. Best results were achieved at 42 degrees C with K. marxianus L. G. and K. fragilis L. G., both of which produced close to 38 g/L ethanol and 0.5 ethanol yield, in 78 h.

Enhanced Ethanol Production from De-Ashed Paper Sludge by Simultaneous Saccharification and Fermentation and Simultaneous Saccharification and Co-Fermentation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kang, L.; Wang, W.; Pallapolu, V. R.

2011-11-01

A previous study demonstrated that paper sludges with high ash contents can be converted to ethanol by simultaneous saccharification and fermentation (SSF) or simultaneous saccharification and co-fermentation (SSCF). High ash content in the sludge, however, limited solid loading in the bioreactor, causing low product concentration. To overcome this problem, sludges were de-ashed before SSF and SSCF. Low ash content in sludges also increased the ethanol yield to the extent that the enzyme dosage required to achieve 70% yield in the fermentation process was reduced by 30%. High solid loading in SSF and SSCF decreased the ethanol yield. High agitation andmore » de-ashing of the sludges were able to restore the part of the yield loss caused by high solid loading. Substitution of the laboratory fermentation medium (peptone and yeast extract) with corn steep liquor did not bring about any adverse effects in the fermentation. Fed-batch operation of the SSCF and SSF using low-ash content sludges was effective in raising the ethanol concentration, achieving 47.8 g/L and 60.0 g/L, respectively.« less

Simultaneous saccharification and fermentation of Agave tequilana fructans by Kluyveromyces marxianus yeasts for bioethanol and tequila production.

PubMed

Flores, Jose-Axel; Gschaedler, Anne; Amaya-Delgado, Lorena; Herrera-López, Enrique J; Arellano, Melchor; Arrizon, Javier

2013-10-01

Agave tequilana fructans (ATF) constitute a substrate for bioethanol and tequila industries. As Kluyveromyces marxianus produces specific fructanases for ATF hydrolysis, as well as ethanol, it can perform simultaneous saccharification and fermentation. In this work, fifteen K. marxianus yeasts were evaluated to develop inoculums with fructanase activity on ATF. These inoculums were added to an ATF medium for simultaneous saccharification and fermentation. All the yeasts, showed exo-fructanhydrolase activity with different substrate specificities. The yeast with highest fructanase activity in the inoculums showed the lowest ethanol production level (20 g/l). Five K. marxianus strains were the most suitable for the simultaneous saccharification and fermentation of ATF. The volatile compounds composition was evaluated at the end of fermentation, and a high diversity was observed between yeasts, nevertheless all of them produced high levels of isobutyl alcohol. The simultaneous saccharification and fermentation of ATF with K. marxianus strains has potential for industrial application. Copyright © 2013 Elsevier Ltd. All rights reserved.

A novel GH10 xylanase from Penicillium sp. accelerates saccharification of alkaline-pretreated bagasse by an enzyme from recombinant Trichoderma reesei expressing Aspergillus β-glucosidase.

PubMed

Shibata, Nozomu; Suetsugu, Mari; Kakeshita, Hiroshi; Igarashi, Kazuaki; Hagihara, Hiroshi; Takimura, Yasushi

2017-01-01

Trichoderma reesei is considered a candidate fungal enzyme producer for the economic saccharification of cellulosic biomass. However, performance of the saccharifying enzymes produced by T. reesei is insufficient. Therefore, many attempts have been made to improve its performance by heterologous protein expression. In this study, to increase the conversion efficiency of alkaline-pretreated bagasse to sugars, we conducted screening of biomass-degrading enzymes that showed synergistic effects with enzyme preparations produced by recombinant T. reesei . Penicillium sp. strain KSM-F532 produced the most effective enzyme to promote the saccharification of alkaline-pretreated bagasse. Biomass-degrading enzymes from strain KSM-F532 were fractionated and analyzed, and a xylanase, named PspXyn10, was identified. The amino acid sequence of PspXyn10 was determined by cDNA analysis: the enzyme shows a modular structure consisting of glycoside hydrolase family 10 (GH10) and carbohydrate-binding module family 1 (CBM1) domains. Purified PspXyn10 was prepared from the supernatant of a recombinant T. reesei strain. The molecular weight of PspXyn10 was estimated to be 55 kDa, and its optimal temperature and pH for xylanase activity were 75 °C and pH 4.5, respectively. More than 80% of the xylanase activity was maintained at 65 °C for 10 min. With beechwood xylan as the substrate, the enzyme had a K m of 2.2 mg/mL and a V max of 332 μmol/min/mg. PspXyn10ΔCBM, which lacked the CBM1 domain, was prepared by limited proteolysis. PspXyn10ΔCBM showed increased activity against soluble xylan, but decreased saccharification efficiency of alkaline-pretreated bagasse. This result indicated that the CBM1 domain of PspXyn10 contributes to the enhancement of the saccharification efficiency of alkaline-pretreated bagasse. A recombinant T. reesei strain, named X2PX10, was constructed from strain X3AB1. X3AB1 is an Aspergillus aculeatus β-glucosidase-expressing T. reesei PC-3-7. X2PX10

Modeling fixed and fluidized reactors for cassava starch Saccharification with immobilized enzyme

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zanin, G.M.; De Moraes, F.F.

1997-12-31

Cassava starch saccharification in fixed-and fluidized-bed reactors using immobilized enzyme was modeled in a previous paper using a simple model in which all dextrins were grouped in a single substrate. In that case, although good fit of the model to experimental data was obtained, physical inconsistency appeared as negative kinetic constants. In this work, a multisubstrate model, developed earlier for saccharification with free enzyme, is adapted for immobilized enzyme. This latter model takes into account the formation of intermediate substrates, which are dextrins competing for the catalytic site of the enzyme, reversibility of some reactions, inhibition by substrate and product,more » and the formation of isomaltose. Kinetic parameters to be used with this model were obtained from initial velocity saccharification tests using the immobilized enzyme and different liquefied starch concentrations. The new model was found to be valid for modeling both fixed- and fluidized-bed reactors. It did not present inconsistencies as the earlier one had and has shown that apparent glucose inhibition is about seven times higher in the fixed-bed than in fluidized-bed reactor. 13 refs., 5 figs., 1 tab.« less

Screening, identification, and characterization of a GH43 family β-xylosidase/α-arabinofuranosidase from a compost microbial metagenome.

PubMed

Matsuzawa, Tomohiko; Kaneko, Satoshi; Yaoi, Katsuro

2015-11-01

A putative glycoside hydrolase family 43 β-xylosidase/α-arabinofuranosidase (CoXyl43) that promotes plant biomass saccharification was isolated via functional screening of a compost microbial metagenomic library and characterized. CoXyl43 promoted the saccharification of plant biomasses, including xylans (xylan and arabinoxylan), rice straw, and Erianthus, by degrading xylooligosaccharide residues to monosaccharide residues. The recombinant CoXyl43 protein exhibited both β-xylosidase and α-arabinofuranosidase activities for chromogenic substrates, with optimal activity at pH 7.5 and 55 °C. Both of these activities were inactivated by ethanol, dimethylsulfoxide, and zinc and copper ions but were activated by manganese ions. Only the β-xylosidase activity of recombinant CoXyl43 was enhanced in the presence of calcium ions. These results indicate that CoXyl43 exhibits unique enzymatic properties useful for biomass saccharification.

Saccharification of Miscanthus x giganteus, incorporation of lignocellulosic by-product in cementitious matrix.

PubMed

Le Ngoc Huyen, Tran; Queneudec T'kint, Michèle; Remond, Caroline; Chabbert, Brigitte; Dheilly, Rose-Marie

2011-11-01

Given the non competition of miscanthus with food and animal feed, this lignocellulosic species has attracted attention as a possible biofuel resource. However, sustainability of ethanol production from lignocelluloses biomass would imply reduction in the consumption of chemicals and/or energetic means, but also valorization of the lignocellulosic by-product remaining from enzymatic saccharification. Introduction of these by-products into a cementitious matrix could be used in manufacturing a lightweight composite. Miscanthus biomass was submitted to chemical pretreatments followed by saccharification using an enzymatic cocktail. Residues from saccharification were then mixed with a cementitious matrix. Given their mechanical properties and a good adherence between cement and by-product, the hardened materials could be used. However, the delay in the beginning of setting time is too long, which prevents the direct use of by-product into cementitious matrix. Preliminary experiments using a setting accelerator in the cementitious matrix permitted significant reduction in the setting time delay. Copyright © 2011 Académie des sciences. Published by Elsevier SAS. All rights reserved.

Enzymatic saccharification of brown seaweed for production of fermentable sugars.

PubMed

Sharma, Sandeep; Horn, Svein Jarle

2016-08-01

This study shows that high drying temperatures negatively affect the enzymatic saccharification yield of the brown seaweed Saccharina latissima. The optimal drying temperature of the seaweed in terms of enzymatic sugar release was found to be 30°C. The enzymatic saccharification process was optimized by investigating factors such as kinetics of sugar release, enzyme dose, solid loading and different blend ratios of cellulases and an alginate lyase. It was found that the seaweed biomass could be efficiently hydrolysed to fermentable sugars using a commercial cellulase cocktail. The inclusion of a mono-component alginate lyase was shown to improve the performance of the enzyme blend, in particular at high solid loadings. At 25% dry matter loading a combined glucose and mannitol concentration of 74g/L was achieved. Copyright © 2016 Elsevier Ltd. All rights reserved.

Process for whole cell saccharification of lignocelluloses to sugars using a dual bioreactor system

DOEpatents

Lu, Jue [Okemos, MI; Okeke, Benedict [Montgomery, AL

2012-03-27

The present invention describes a process for saccharification of lignocelluloses to sugars using whole microbial cells, which are enriched from cultures inoculated with paper mill waste water, wood processing waste and soil. A three-member bacterial consortium is selected as a potent microbial inocula and immobilized on inedible plant fibers for biomass saccharification. The present invention further relates the design of a dual bioreactor system, with various biocarriers for enzyme immobilization and repeated use. Sugars are continuously removed eliminating end-product inhibition and consumption by cell.

Simultaneous detoxification, saccharification, and ethanol fermentation of weak-acid hydrolyzates

USDA-ARS?s Scientific Manuscript database

Lignocellulosic feedstocks can be prepared for ethanol fermentation by pre-treatment with a dilute mineral acid catalyst that hydrolyzes the hemicellulose and opens up the plant cell wall fibers for subsequent enzymatic saccharification. The acid catalyzed reaction scheme is sequential whereby rele...

One-step process of hydrothermal and alkaline treatment of wheat straw for improving the enzymatic saccharification.

PubMed

Sun, Shaolong; Zhang, Lidan; Liu, Fang; Fan, Xiaolin; Sun, Run-Cang

2018-01-01

To increase the production of bioethanol, a two-step process based on hydrothermal and dilute alkaline treatment was applied to reduce the natural resistance of biomass. However, the process required a large amount of water and a long operation time due to the solid/liquid separation before the alkaline treatment, which led to decrease the pure economic profit for production of bioethanol. Therefore, four one-step processes based on order of hydrothermal and alkaline treatment have been developed to enhance concentration of glucose of wheat straw by enzymatic saccharification. The aim of the present study was to systematically evaluated effect for different one-step processes by analyzing the physicochemical properties (composition, structural change, crystallinity, surface morphology, and BET surface area) and enzymatic saccharification of the treated substrates. In this study, hemicelluloses and lignins were removed from wheat straw and the morphologic structures were destroyed to various extents during the four one-step processes, which were favorable for cellulase absorption on cellulose. A positive correlation was also observed between the crystallinity and enzymatic saccharification rate of the substrate under the conditions given. The surface area of the substrate was positively related to the concentration of glucose in this study. As compared to the control (3.0 g/L) and treated substrates (11.2-14.6 g/L) obtained by the other three one-step processes, the substrate treated by one-step process based on successively hydrothermal and alkaline treatment had a maximum glucose concentration of 18.6 g/L, which was due to the high cellulose concentration and surface area for the substrate, accompanying with removal of large amounts of lignins and hemicelluloses. The present study demonstrated that the order of hydrothermal and alkaline treatment had significant effects on the physicochemical properties and enzymatic saccharification of wheat straw. The one

Batch bioethanol production via the biological and chemical saccharification of some Egyptian marine macroalgae.

PubMed

Soliman, Ramadan M; Younis, Sherif A; El-Gendy, Nour Sh; Mostafa, Soha S M; El-Temtamy, Seham A; Hashim, Ahmed I

2018-04-19

Marine seaweeds (macroalgae) cause eutrophication problem and affects the touristic activities. The success of the production of the third generation bioethanol from marine macroalgae depends mainly on the development of an ecofriendly and eco-feasible pretreatment (i.e. hydrolysis) technique, a highly effective saccharification step and finally an efficient bioethanol fermentation step. Therefore, this study aimed to investigate the potentiality of different marine macroalgal strains, collected from Egyptian coasts, for bioethanol production via different saccharification processes. Different marine macroalgal strains; red Jania rubens, green Ulva lactuca. and brown Sargassum latifolium, have been collected from Egyptian Mediterranean and Red Sea shores. Different hydrolysis processes were evaluated to maximize the extraction of fermentable sugars; thermo-chemical hydrolysis with diluted acids (HCl and H 2 SO 4 ) and base (NaOH), hydrothermal hydrolysis followed by saccharification with different fungal strains and finally, thermo-chemical hydrolysis with diluted HCl, followed by fungal saccharification. The hydrothermal hydrolysis of Sargassum latifolium followed by biological saccharification using Trichoderma asperellum RM1 produced maximum total sugars of 510 mg g -1 macroalgal biomass. The integration of the hydrothermal and fungal hydrolyses of the macroalgal biomass with a separate batch fermentation of the produced sugars using two Saccharomyces cerevisiae strains, produced approximately 0.29 g bioethanol g -1 total reducing sugars. A simulated regression modeling for the batch bioethanol fermentation was also performed. This study, supported the possibility of using seaweeds as a renewable source of bioethanol, throughout a suggested integration of macroalgal biomass hydrothermal- and fungal- hydrolysis with a separate batch bioethanol fermentation process of the produced sugars. The usage of marine macroalgae (i.e. seaweeds) as feedstock for bioethanol

Effect of harvesting date on the composition and saccharification of Miscanthus x giganteus.

PubMed

Le Ngoc Huyen, T; Rémond, C; Dheilly, R M; Chabbert, B

2010-11-01

The chemical composition of the whole aerial biomass and isolated organs of Miscanthus x giganteus was examined for saccharification into fermentable sugars at early and late harvesting dates. Delayed harvest was mainly related to increased amounts of cell wall and ester-linked phenolic acids. Addition of an enzyme cocktail (cellulases, beta-glucosidase and xylanase) resulted in similar enzyme digestibilities at the two harvesting dates, ranging from 11-13% and 8-9% of the cellulose and arabinoxylan, respectively. However, the internodes, leaves and sheaths varied in cell wall content and composition and gave rise to different saccharification yields with internodes being the most recalcitrant organs. Non-cell wall fraction was estimated as the amount of material extracted by neutral detergent solution, and accounted for 23% of the whole aerial biomass harvested at an early date. However, saccharification yields from the miscanthus biomass did not change after soluble fraction removal. An ammonia pretreatment improved enzyme efficiency on early-harvested miscanthus, to a greater extent than on late-harvested biomass. This trend was confirmed for two different years of harvesting. Copyright 2010 Elsevier Ltd. All rights reserved.

Effects of different cellulases on the release of phenolic acids from rice straw during saccharification.

PubMed

Xue, Yiyun; Wang, Xiahui; Chen, Xingxuan; Hu, Jiajun; Gao, Min-Tian; Li, Jixiang

2017-06-01

Effects of different cellulases on the release of phenolic acids from rice straw during saccharification were investigated in this study. All cellulases tested increased the contents of phenolic acids during saccharification. However, few free phenolic acids were detected, as they were present in conjugated form after saccharification when the cellulases from Trichoderma reesei, Trichoderma viride and Aspergillus niger were used. On the other hand, phenolic acids were present in free form when the Acremonium cellulolyticus cellulase was used. Assays of enzyme activity showed that, besides high cellulase activity, the A. cellulolyticus cellulase exhibited high feruloyl esterase (FAE) activity. A synergistic interaction between FAE and cellulase led to the increase in free phenolic acids, and thus an increase in antioxidative and antiradical activities of the phenolic acids. Moreover, a cost estimation demonstrated the feasibility of phenolic acids as value-added products to reduce the total production cost of ethanol. Copyright © 2017 Elsevier Ltd. All rights reserved.

Whole slurry saccharification and fermentation of maleic acid-pretreated rice straw for ethanol production.

PubMed

Jung, Young Hoon; Park, Hyun Min; Kim, Kyoung Heon

2015-09-01

We evaluated the feasibility of whole slurry (pretreated lignocellulose) saccharification and fermentation for producing ethanol from maleic acid-pretreated rice straw. The optimized conditions for pretreatment were to treat rice straw at a high temperature (190 °C) with 1 % (w/v) maleic acid for a short duration (3 min ramping to 190 °C and 3 min holding at 190 °C). Enzymatic digestibility (based on theoretical glucose yield) of cellulose in the pretreated rice straw was 91.5 %. Whole slurry saccharification and fermentation of pretreated rice straw resulted in 83.2 % final yield of ethanol based on the initial quantity of glucan in untreated rice straw. These findings indicate that maleic acid pretreatment results in a high yield of ethanol from fermentation of whole slurry even without conditioning or detoxification of the slurry. Additionally, the separation of solids and liquid is not required; therefore, the economics of cellulosic ethanol fuel production are significantly improved. We also demonstrated whole slurry saccharification and fermentation of pretreated lignocellulose, which has rarely been reported.

Display screen and method of manufacture therefor

NASA Technical Reports Server (NTRS)

Dubin, Matthew B. (Inventor); Larson, Brent D. (Inventor)

2002-01-01

A screen assembly that combines an angle re-distributing prescreen with a conventional diffusion screen. The prescreen minimizes or eliminates the sensitivity of the screen assembly to projector location. The diffusion screen provides other desirable screen characteristics. Compatible screen structures, along with methods for fabricating high resolution prescreens and methods and devices for maintaining the desired relationship between the prescreen and the diffusion screen are contemplated.

Analysis, pretreatment and enzymatic saccharification of different fractions of Scots pine

PubMed Central

2014-01-01

Background Forestry residues consisting of softwood are a major lignocellulosic resource for production of liquid biofuels. Scots pine, a commercially important forest tree, was fractionated into seven fractions of chips: juvenile heartwood, mature heartwood, juvenile sapwood, mature sapwood, bark, top parts, and knotwood. The different fractions were characterized analytically with regard to chemical composition and susceptibility to dilute-acid pretreatment and enzymatic saccharification. Results All fractions were characterized by a high glucan content (38-43%) and a high content of other carbohydrates (11-14% mannan, 2-4% galactan) that generate easily convertible hexose sugars, and by a low content of inorganic material (0.2-0.9% ash). The lignin content was relatively uniform (27-32%) and the syringyl-guaiacyl ratio of the different fractions were within the range 0.021-0.025. The knotwood had a high content of extractives (9%) compared to the other fractions. The effects of pretreatment and enzymatic saccharification were relatively similar, but without pretreatment the bark fraction was considerably more susceptible to enzymatic saccharification. Conclusions Since sawn timber is a main product from softwood species such as Scots pine, it is an important issue whether different parts of the tree are equally suitable for bioconversion processes. The investigation shows that bioconversion of Scots pine is facilitated by that most of the different fractions exhibit relatively similar properties with regard to chemical composition and susceptibility to techniques used for bioconversion of woody biomass. PMID:24641769

Analysis, pretreatment and enzymatic saccharification of different fractions of Scots pine.

PubMed

Normark, Monica; Winestrand, Sandra; Lestander, Torbjörn A; Jönsson, Leif J

2014-03-19

Forestry residues consisting of softwood are a major lignocellulosic resource for production of liquid biofuels. Scots pine, a commercially important forest tree, was fractionated into seven fractions of chips: juvenile heartwood, mature heartwood, juvenile sapwood, mature sapwood, bark, top parts, and knotwood. The different fractions were characterized analytically with regard to chemical composition and susceptibility to dilute-acid pretreatment and enzymatic saccharification. All fractions were characterized by a high glucan content (38-43%) and a high content of other carbohydrates (11-14% mannan, 2-4% galactan) that generate easily convertible hexose sugars, and by a low content of inorganic material (0.2-0.9% ash). The lignin content was relatively uniform (27-32%) and the syringyl-guaiacyl ratio of the different fractions were within the range 0.021-0.025. The knotwood had a high content of extractives (9%) compared to the other fractions. The effects of pretreatment and enzymatic saccharification were relatively similar, but without pretreatment the bark fraction was considerably more susceptible to enzymatic saccharification. Since sawn timber is a main product from softwood species such as Scots pine, it is an important issue whether different parts of the tree are equally suitable for bioconversion processes. The investigation shows that bioconversion of Scots pine is facilitated by that most of the different fractions exhibit relatively similar properties with regard to chemical composition and susceptibility to techniques used for bioconversion of woody biomass.

Final Technical Report - Consolidating Biomass Pretreatment with Saccharification by Resolving the Spatial Control Mechanisms of Fungi

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schilling, Jonathan

Consolidated bioprocessing (CBP) of lignocellulose combines enzymatic sugar release (saccharification) with fermentation, but pretreatments remain separate and costly. In nature, lignocellulose-degrading brown rot fungi consolidate pretreatment and saccharification, likely using spatial gradients to partition these incompatible reactions. With the field of biocatalysis maturing, reaction partitioning is increasingly reproducible for commercial use. Therefore, my goal was to resolve the reaction partitioning mechanisms of brown rot fungi so that they can be applied to bioconversion of lignocellulosic feedstocks. Brown rot fungi consolidate oxidative pretreatments with saccharification and are a focus for biomass refining because 1) they attain >99% sugar yield without destroyingmore » lignin, 2) they use a simplified cellulase suite that lacks exoglucanase, and 3) their non-enzymatic pretreatment is facilitative and may be accelerated. Specifically, I hypothesized that during brown rot, oxidative pretreatments occur ahead of enzymatic saccharification, spatially, and the fungus partitions these reactions using gradients in pH, lignin reactivity, and plant cell wall porosity. In fact, we found three key results during these experiments for this work: 1) Brown rot fungi have an inducible cellulase system, unlike previous descriptions of a constitutive mechanism. 2) The induction of cellulases is delayed until there is repression of oxidatively-linked genes, allowing the brown rot fungi to coordinate two incompatible reactions (oxidative pretreatment with enzymatic saccharification, to release wood sugars) in the same pieces of wood. 3) This transition is mediated by the same wood sugar, cellobiose, released by the oxidative pretreatment step. Collectively, these findings have been published in excellent journal outlets and have been presented at conferences around the United States, and they offer clear targets for gene discovery en route to making biofuels and

Enhanced enzymatic hydrolysis of waste paper for ethanol production using separate saccharification and fermentation.

PubMed

Guerfali, Mohamed; Saidi, Adel; Gargouri, Ali; Belghith, Hafedh

2015-01-01

Ethanol produced from lignocellulosic biomass is a renewable alternative to diminishing petroleum-based liquid fuels. In this study, the feasibility of ethanol production from waste paper using the separate hydrolysis and fermentation (SHF) was investigated. Two types of waste paper materials, newspaper and office paper, were evaluated for their potential to be used as a renewable feedstock for the production of fermentable sugars via enzymatic hydrolysis of their cellulose fractions. Hydrolysis step was conducted with a mixture of cellulolytic enzymes produced locally by Trichoderma reesei Rut-C30 (cellulase-overproducing mutant) and Aspergillus niger F38 cultures. Surfactant pretreatment effect on waste paper enzymatic digestibility was studied and Triton X-100 at 0.5 % (w w(-1)) has improved the digestibility of newspaper about 45 %. The effects of three factors (dry matter quantity, phosphoric acid pretreatment and hydrolysis time) on the extent of saccharification were also assessed and quantified by using a methodical approach based on response surface methodology. Under optimal hydrolysis conditions, maximum degrees of saccharification of newspaper and office paper were 67 and 92 %, respectively. Sugars released from waste paper were subsequently converted into ethanol (0.38 g ethanol g(-1) sugar) with Saccharomyces cerevisiae CTM-30101.

Improvement of enzymatic saccharification yield in Arabidopsis thaliana by ectopic expression of the rice SUB1A-1 transcription factor

PubMed Central

Núñez-López, Lizeth; Aguirre-Cruz, Andrés

2015-01-01

Saccharification of polysaccharides releases monosaccharides that can be used by ethanol-producing microorganisms in biofuel production. To improve plant biomass as a raw material for saccharification, factors controlling the accumulation and structure of carbohydrates must be identified. Rice SUB1A-1 is a transcription factor that represses the turnover of starch and postpones energy-consuming growth processes under submergence stress. Arabidopsis was employed to test if heterologous expression of SUB1A-1 or SUB1C-1 (a related gene) can be used to improve saccharification. Cellulolytic and amylolytic enzymatic treatments confirmed that SUB1A-1 transgenics had better saccharification yield than wild-type (Col-0), mainly from accumulated starch. This improved saccharification yield was developmentally controlled; when compared to Col-0, young transgenic vegetative plants yielded 200–300% more glucose, adult vegetative plants yielded 40–90% more glucose and plants in reproductive stage had no difference in yield. We measured photosynthetic parameters, starch granule microstructure, and transcript abundance of genes involved in starch degradation (SEX4, GWD1), juvenile transition (SPL3-5) and meristematic identity (FUL, SOC1) but found no differences to Col-0, indicating that starch accumulation may be controlled by down-regulation of CONSTANS and FLOWERING LOCUS T by SUB1A-1 as previously reported. SUB1A-1 transgenics also offered less resistance to deformation than wild-type concomitant to up-regulation of AtEXP2 expansin and BGL2 glucan-1,3,-beta-glucosidase. We conclude that heterologous SUB1A-1 expression can improve saccharification yield and softness, two traits needed in bioethanol production. PMID:25780769

Development of cellulase-nanoconjugates with enhanced ionic liquid and thermal stability for in situ lignocellulose saccharification.

PubMed

Grewal, Jasneet; Ahmad, Razi; Khare, S K

2017-10-01

The present work aimed to improve catalytic efficiency of Trichoderma reesei cellulase for enhanced saccharification. The cellulase was immobilized on two nanomatrices i.e. magnetic and silica nanoparticles with immobilization efficiency of 85% and 76% respectively. The nanobioconjugates exhibited increase in V max , temperature optimum, pH and thermal stability as compared with free enzyme. These could be efficiently reused for five repeated cycles and were stable in 1-ethyl-3-methylimidazoliumacetate [EMIM][Ac], an ionic liquid. Ionic liquids (IL) are used as green solvents to dissolve lignocellulosic biomass and facilitate better saccharification. The cellulase immobilized on magnetic nanoparticles was used for in situ saccharification of [EMIM][Ac] pretreated sugarcane bagasse and wheat straw for two cycles. The structural deconstruction and decrease in biomass crystallinity was confirmed by SEM, XRD and FTIR. The high hydrolysis yields (∼89%) obtained in this one-pot process coupled with IL stability and recycled use of immobilized cellulase, potentiates its usefulness in biorefineries. Copyright © 2017 Elsevier Ltd. All rights reserved.

Simultaneous pretreatment and saccharification: green technology for enhanced sugar yields from biomass using a fungal consortium.

PubMed

Dhiman, Saurabh Sudha; Haw, Jung-Rim; Kalyani, Dayanand; Kalia, Vipin C; Kang, Yun Chan; Lee, Jung-Kul

2015-03-01

Two different biomasses were subjected to simultaneous pretreatment and saccharification (SPS) using a cocktail of hydrolytic and oxidizing enzymes. Application of a novel laccase as a detoxifying agent caused the removal of 49.8% and 32.6% of phenolic contents from the soaked rice straw and willow, respectively. Hydrolysis of soaked substrates using a newly developed fungal consortium resulted in saccharification yield of up to 74.2% and 63.6% for rice straw and willow, respectively. A high saccharification yield was obtained with soaked rice straw and willow without using any hazardous chemicals. The efficiency of each step related to SPS was confirmed by atomic force microscopy. The suitability of the developed SPS process was further confirmed by converting the hydrolysate from the process into bioethanol with 72.4% sugar conversion efficiency. To the best of our knowledge, this is the first report on the development of a less tedious, single-pot, and eco-friendly SPS methodology. Copyright © 2014 Elsevier Ltd. All rights reserved.

Evaluation of hydrate-screening methods.

PubMed

Cui, Yong; Yao, Erica

2008-07-01

The purpose of this work is to evaluate the effectiveness and reliability of several common hydrate-screening techniques, and to provide guidelines for designing hydrate-screening programs for new drug candidates. Ten hydrate-forming compounds were selected as model compounds and six hydrate-screening approaches were applied to these compounds in an effort to generate their hydrate forms. The results prove that no screening approach is universally effective in finding hydrates for small organic compounds. Rather, a combination of different methods should be used to improve screening reliability. Among the approaches tested, the dynamic water vapor sorption/desorption isotherm (DVI) method and storage under high humidity (HH) yielded 60-70% success ratios, the lowest among all techniques studied. The risk of false negatives arises in particular for nonhygroscopic compounds. On the other hand, both slurry in water (Slurry) and temperature cycling of aqueous suspension (TCS) showed high success rates (90%) with some exceptions. The mixed solvent systems (MSS) procedure also achieved high success rates (90%), and was found to be more suitable for water-insoluble compounds. For water-soluble compounds, MSS may not be the best approach because recrystallization is difficult in solutions with high water activity. Finally, vapor diffusion (VD) yielded a reasonably high success ratio in finding hydrates (80%). However, this method suffers from experimental difficulty and unreliable results for either highly water-soluble or water-insoluble compounds. This study indicates that a reliable hydrate-screening strategy should take into consideration the solubility and hygroscopicity of the compounds studied. A combination of the Slurry or TCS method with the MSS procedure could provide a screening strategy with reasonable reliability.

Microwave-assisted inorganic salt pretreatment of sugarcane leaf waste: Effect on physiochemical structure and enzymatic saccharification.

PubMed

Moodley, Preshanthan; Kana, E B Gueguim

2017-07-01

This paper presents a method to pretreat sugarcane leaf waste using microwave-assisted (MA) inorganic salt to enhance enzymatic saccharification. The effects of process parameters of salt concentration, microwave power intensity and pretreatment time on reducing sugar yield from sugarcane leaf waste were investigated. Pretreatment models based on MA-NaCl, MA-ZnCl 2 and MA-FeCl 3 were developed with high coefficients of determination (R 2 >0.8) and optimized. Maximum reducing sugar yield of 0.406g/g was obtained with 2M FeCl 3 at 700W for 3.5min. Scanning electron microscopy (SEM), Fourier Transform Infrared analysis (FTIR) and X-ray diffraction (XRD) showed major changes in lignocellulosic structure after MA-FeCl 3 pretreatment with 71.5% hemicellulose solubilization. This regime was further assessed on sorghum leaves and Napier grass under optimal MA-FeCl 3 conditions. A 2-fold and 3.1-fold increase in sugar yield respectively were observed compared to previous reports. This pretreatment was highly effective for enhancing enzymatic saccharification of lignocellulosic biomass. Copyright © 2017. Published by Elsevier Ltd.

A new beta-glucosidase producing yeast for lower-cost cellulosic ethanol production from xylose-extracted corncob residues by simultaneous saccharification and fermentation

USDA-ARS?s Scientific Manuscript database

Conventional cellulose-to-ethanol conversion by simultaneous saccharification and fermentation (SSF)requires enzymatic saccharification using both cellulase and ß-glucosidase allowing cellulose utilization by common ethanologenic yeast. Here we report a new yeast strain of Clavispora NRRL Y-50464 th...

Lignin triggers irreversible cellulase loss during pretreated lignocellulosic biomass saccharification.

PubMed

Gao, Dahai; Haarmeyer, Carolyn; Balan, Venkatesh; Whitehead, Timothy A; Dale, Bruce E; Chundawat, Shishir Ps

2014-01-01

Non-productive binding of enzymes to lignin is thought to impede the saccharification efficiency of pretreated lignocellulosic biomass to fermentable sugars. Due to a lack of suitable analytical techniques that track binding of individual enzymes within complex protein mixtures and the difficulty in distinguishing the contribution of productive (binding to specific glycans) versus non-productive (binding to lignin) binding of cellulases to lignocellulose, there is currently a poor understanding of individual enzyme adsorption to lignin during the time course of pretreated biomass saccharification. In this study, we have utilized an FPLC (fast protein liquid chromatography)-based methodology to quantify free Trichoderma reesei cellulases (namely CBH I, CBH II, and EG I) concentration within a complex hydrolyzate mixture during the varying time course of biomass saccharification. Three pretreated corn stover (CS) samples were included in this study: Ammonia Fiber Expansion(a) (AFEX™-CS), dilute acid (DA-CS), and ionic liquid (IL-CS) pretreatments. The relative fraction of bound individual cellulases varied depending not only on the pretreated biomass type (and lignin abundance) but also on the type of cellulase. Acid pretreated biomass had the highest levels of non-recoverable cellulases, while ionic liquid pretreated biomass had the highest overall cellulase recovery. CBH II has the lowest thermal stability among the three T. reesei cellulases tested. By preparing recombinant family 1 carbohydrate binding module (CBM) fusion proteins, we have shown that family 1 CBMs are highly implicated in the non-productive binding of full-length T. reesei cellulases to lignin. Our findings aid in further understanding the complex mechanisms of non-productive binding of cellulases to pretreated lignocellulosic biomass. Developing optimized pretreatment processes with reduced or modified lignin content to minimize non-productive enzyme binding or engineering pretreatment

Recombinant hosts suitable for simultaneous saccharification and fermentation

DOEpatents

Ingram, Lonnie O'Neal; Zhou, Shengde

2007-06-05

The invention provides recombinant host cells containing at least one heterologous polynucleotide encoding a polysaccharase under the transcriptional control of a surrogate promoter capable of increasing the expression of the polysaccharase. In addition, the invention further provides such hosts with genes encoding secretory protein/s to facilitate the secretion of the expressed polysaccharase. Preferred hosts of the invention are ethanologenic and capable of carrying out simultaneous saccharification fermentation resulting in the production of ethanol from complex cellulose substrates.

Enhancement of In Situ Enzymatic Saccharification of Corn Stover by a Stepwise Sodium Hydroxide and Organic Acid Pretreatment.

PubMed

Qing, Qing; Guo, Qi; Zhou, Linlin; He, Yucai; Wang, Liqun; Zhang, Yue

2017-01-01

A stepwise pretreatment method that combines sodium hydroxide and organic acid pretreatments was proposed and investigated to maximize the recovery of main constituents of lignocellulose. The sodium hydroxide pretreatment was firstly optimized by a designed orthogonal experiment with the optimum pretreatment conditions determined as 1 wt% NaOH at 70 °C for 1 h, and 60.42 % of lignin was successfully removed during this stage. In the second stage, 0.5 % acetic acid was selected to pretreat the first-stage solid residue at 80 °C for 40 min in order to decompose hemicelluloses to soluble oligomers or monomers. Then, the whole slurry was subjected to in situ enzymatic saccharification by cellullase with a supplementation of xylanase to further degrade the xylooligosaccharides generated during the acetic acid pretreatment. The maximum reducing sugar and glucose yields achieved were 20.74 and 12.03 g/L, respectively. Furthermore, rapid ethanol fermentation and a yield of 80.3 % also testified this pretreatment method, and the in situ saccharification did not bring any negative impact on ethanol fermentation and has a broad application prospect.

LANL seismic screening method for existing buildings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dickson, S.L.; Feller, K.C.; Fritz de la Orta, G.O.

1997-01-01

The purpose of the Los Alamos National Laboratory (LANL) Seismic Screening Method is to provide a comprehensive, rational, and inexpensive method for evaluating the relative seismic integrity of a large building inventory using substantial life-safety as the minimum goal. The substantial life-safety goal is deemed to be satisfied if the extent of structural damage or nonstructural component damage does not pose a significant risk to human life. The screening is limited to Performance Category (PC) -0, -1, and -2 buildings and structures. Because of their higher performance objectives, PC-3 and PC-4 buildings automatically fail the LANL Seismic Screening Method andmore » will be subject to a more detailed seismic analysis. The Laboratory has also designated that PC-0, PC-1, and PC-2 unreinforced masonry bearing wall and masonry infill shear wall buildings fail the LANL Seismic Screening Method because of their historically poor seismic performance or complex behavior. These building types are also recommended for a more detailed seismic analysis. The results of the LANL Seismic Screening Method are expressed in terms of separate scores for potential configuration or physical hazards (Phase One) and calculated capacity/demand ratios (Phase Two). This two-phase method allows the user to quickly identify buildings that have adequate seismic characteristics and structural capacity and screen them out from further evaluation. The resulting scores also provide a ranking of those buildings found to be inadequate. Thus, buildings not passing the screening can be rationally prioritized for further evaluation. For the purpose of complying with Executive Order 12941, the buildings failing the LANL Seismic Screening Method are deemed to have seismic deficiencies, and cost estimates for mitigation must be prepared. Mitigation techniques and cost-estimate guidelines are not included in the LANL Seismic Screening Method.« less

Distinct Geographical Distribution of the Miscanthus Accessions with Varied Biomass Enzymatic Saccharification

PubMed Central

Li, Xukai; Liao, Haofeng; Fan, Chunfen; Hu, Huizhen; Li, Ying; Li, Jing; Yi, Zili; Cai, Xiwen; Peng, Liangcai; Tu, Yuanyuan

2016-01-01

Miscanthus is a leading bioenergy candidate for biofuels, and it thus becomes essential to characterize the desire natural Miscanthus germplasm accessions with high biomass saccharification. In this study, total 171 natural Miscanthus accessions were geographically mapped using public database. According to the equation [P(H/L| East) = P(H/L∩East)/P(East)], the probability (P) parameters were calculated on relationships between geographical distributions of Miscanthus accessions in the East of China, and related factors with high(H) or low(L) values including biomass saccahrification under 1% NaOH and 1% H2SO4 pretreatments, lignocellulose features and climate conditions. Based on the maximum P value, a golden cutting line was generated from 42°25’ N, 108°22’ E to 22°58’ N, 116°28’ E on the original locations of Miscanthus accessions with high P(H|East) values (0.800–0.813), indicating that more than 90% Miscanthus accessions were originally located in the East with high biomass saccharification. Furthermore, the averaged insolation showed high P (H|East) and P(East|H) values at 0.782 and 0.754, whereas other climate factors had low P(East|H) values, suggesting that the averaged insolation is unique factor on Miscanthus distributions for biomass saccharification. In terms of cell wall compositions and wall polymer features, both hemicelluloses level and cellulose crystallinity (CrI) of Miscanthus accessions exhibited relative high P values, suggesting that they should be the major factors accounting for geographic distributions of Miscanthus accessions with high biomass digestibility. PMID:27532636

An Electrochemical Impedance Spectroscopy System for Monitoring Pineapple Waste Saccharification.

PubMed

Conesa, Claudia; Ibáñez Civera, Javier; Seguí, Lucía; Fito, Pedro; Laguarda-Miró, Nicolás

2016-02-04

Electrochemical impedance spectroscopy (EIS) has been used for monitoring the enzymatic pineapple waste hydrolysis process. The system employed consists of a device called Advanced Voltammetry, Impedance Spectroscopy & Potentiometry Analyzer (AVISPA) equipped with a specific software application and a stainless steel double needle electrode. EIS measurements were conducted at different saccharification time intervals: 0, 0.75, 1.5, 6, 12 and 24 h. Partial least squares (PLS) were used to model the relationship between the EIS measurements and the sugar determination by HPAEC-PAD. On the other hand, artificial neural networks: (multilayer feed forward architecture with quick propagation training algorithm and logistic-type transfer functions) gave the best results as predictive models for glucose, fructose, sucrose and total sugars. Coefficients of determination (R²) and root mean square errors of prediction (RMSEP) were determined as R² > 0.944 and RMSEP < 1.782 for PLS and R² > 0.973 and RMSEP < 0.486 for artificial neural networks (ANNs), respectively. Therefore, a combination of both an EIS-based technique and ANN models is suggested as a promising alternative to the traditional laboratory techniques for monitoring the pineapple waste saccharification step.

An Electrochemical Impedance Spectroscopy System for Monitoring Pineapple Waste Saccharification

PubMed Central

Conesa, Claudia; Ibáñez Civera, Javier; Seguí, Lucía; Fito, Pedro; Laguarda-Miró, Nicolás

2016-01-01

Electrochemical impedance spectroscopy (EIS) has been used for monitoring the enzymatic pineapple waste hydrolysis process. The system employed consists of a device called Advanced Voltammetry, Impedance Spectroscopy & Potentiometry Analyzer (AVISPA) equipped with a specific software application and a stainless steel double needle electrode. EIS measurements were conducted at different saccharification time intervals: 0, 0.75, 1.5, 6, 12 and 24 h. Partial least squares (PLS) were used to model the relationship between the EIS measurements and the sugar determination by HPAEC-PAD. On the other hand, artificial neural networks: (multilayer feed forward architecture with quick propagation training algorithm and logistic-type transfer functions) gave the best results as predictive models for glucose, fructose, sucrose and total sugars. Coefficients of determination (R2) and root mean square errors of prediction (RMSEP) were determined as R2 > 0.944 and RMSEP < 1.782 for PLS and R2 > 0.973 and RMSEP < 0.486 for artificial neural networks (ANNs), respectively. Therefore, a combination of both an EIS-based technique and ANN models is suggested as a promising alternative to the traditional laboratory techniques for monitoring the pineapple waste saccharification step. PMID:26861317

Associating cooking additives with sodium hydroxide to pretreat bamboo residues for improving the enzymatic saccharification and monosaccharides production.

PubMed

Huang, Caoxing; He, Juan; Wang, Yan; Min, Douyong; Yong, Qiang

2015-10-01

Cooking additive pulping technique is used in kraft mill to increase delignification degree and pulp yield. In this work, cooking additives were firstly applied in the sodium hydroxide pretreatment for improving the bioconversion of bamboo residues to monosaccharides. Meanwhile, steam explosion and sulfuric acid pretreatments were also carried out on the sample to compare their impacts on monosaccharides production. Results indicated that associating anthraquinone with sodium hydroxide pretreatment showed the best performance in improving the original carbohydrates recovery, delignification, enzymatic saccharification, and monosaccharides production. After consecutive pretreatment and enzymatic saccharification process, 347.49 g, 307.48 g, 142.93 g, and 87.15 g of monosaccharides were released from 1000 g dry bamboo residues pretreated by sodium hydroxide associating with anthraquinone, sodium hydroxide, steam explosion and sulfuric acid, respectively. The results suggested that associating cooking additive with sodium hydroxide is an effective pretreatment for bamboo residues to enhance enzymatic saccharification for monosaccharides production. Copyright © 2015 Elsevier Ltd. All rights reserved.

Valorisation of food and beverage waste via saccharification for sugars recovery.

PubMed

Kwan, Tsz Him; Ong, Khai Lun; Haque, Md Ariful; Kwan, Wing Hei; Kulkarni, Sandeep; Lin, Carol Sze Ki

2018-05-01

Valorisation of mixed food and beverage (F&B) waste was studied for the recovery of sugars via saccharification. Glucoamylase and sucrase were employed to hydrolyse the starch and sucrose present in the mixed F&B waste because of the high cost-effectiveness for such recovery. The Michaelis-Menten kinetics model suggests that preservatives and additives in beverages did not inhibit glucoamylase and sucrase during saccharification. High levels of glucose (228.1 g L -1 ) and fructose (55.7 g L -1 ) were efficiently produced within 12 h at a solid-to-liquid ratio of 37.5% (w/v) in 2.5 L bioreactors. An overall conversion yield of 0.17 g sugars per g of mixed F&B waste was obtained in mass balance analysis. Lastly, possible industrial applications of the sugar-rich hydrolysate and by-products are discussed. This study is believed to cast insights into F&B waste recycling via biotechnology to produce high-value added products to promote the establishment of a circular bio-economy. Copyright © 2018 Elsevier Ltd. All rights reserved.

Enzymatic saccharification and bioethanol production from Cynara cardunculus pretreated by steam explosion.

PubMed

Fernandes, Maria C; Ferro, Miguel D; Paulino, Ana F C; Mendes, Joana A S; Gravitis, Janis; Evtuguin, Dmitry V; Xavier, Ana M R B

2015-06-01

The correct choice of the specific lignocellulosic biomass pretreatment allows obtaining high biomass conversions for biorefinery implementations and cellulosic bioethanol production from renewable resources. Cynara cardunculus (cardoon) pretreated by steam explosion (SE) was involved in second-generation bioethanol production using separate hydrolysis and fermentation (SHF) or simultaneous saccharification and fermentation (SSF) processes. Steam explosion pretreatment led to partial solubilisation of hemicelluloses and increased the accessibility of residual polysaccharides towards enzymatic hydrolysis revealing 64% of sugars yield against 11% from untreated plant material. Alkaline extraction after SE pretreatment of cardoon (CSEOH) promoted partial removal of degraded lignin, tannins, extractives and hemicelluloses thus allowing to double glucose concentration upon saccharification step. Bioethanol fermentation in SSF mode was faster than SHF process providing the best results: ethanol concentration 18.7 g L(-1), fermentation efficiency of 66.6% and a yield of 26.6g ethanol/100 g CSEOH or 10.1 g ethanol/100 g untreated cardoon. Copyright © 2015 Elsevier Ltd. All rights reserved.

Peracetic acid-ionic liquid pretreatment to enhance enzymatic saccharification of lignocellulosic biomass.

PubMed

Uju; Abe, Kojiro; Uemura, Nobuyuki; Oshima, Toyoji; Goto, Masahiro; Kamiya, Noriho

2013-06-01

To enhance enzymatic saccharification of pine biomass, the pretreatment reagents peracetic acid (PAA) and ionic liquid (IL) were validated in single reagent pretreatments or combination pretreatments with different sequences. In a 1h saccharification, 5-25% cellulose conversion was obtained from the single pretreatment of PAA or IL. In contrast, a marked enhancement in conversion rates was achieved by PAA-IL combination pretreatments (45-70%). The PAA followed by IL (PAA+IL) pretreatment sequence was the most effective for preparing an enzymatic digestible regenerated biomass with 250-fold higher glucose formation rates than untreated biomass and 2- to 12-fold higher than single pretreatments with PAA or IL alone. Structural analysis confirmed that this pretreatment resulted in biomass with highly porous structural fibers associated with the reduction of lignin content and acetyl groups. Using the PAA+IL sequence, biomass loading in the pretreatment step can be increased from 5% to 15% without significant decrease in cellulose conversion. Copyright © 2013 Elsevier Ltd. All rights reserved.

42 CFR 455.452 - Other State screening methods.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 42 Public Health 4 2013-10-01 2013-10-01 false Other State screening methods. 455.452 Section 455....452 Other State screening methods. Nothing in this subpart must restrict the State Medicaid agency from establishing provider screening methods in addition to or more stringent than those required by...

42 CFR 455.452 - Other State screening methods.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 42 Public Health 4 2011-10-01 2011-10-01 false Other State screening methods. 455.452 Section 455....452 Other State screening methods. Nothing in this subpart must restrict the State Medicaid agency from establishing provider screening methods in addition to or more stringent than those required by...

Optimization of liquid fermentation of microbial consortium WSD-5 followed by saccharification and acidification of wheat straw.

PubMed

Wen, Boting; Yuan, Xufeng; Cao, Yanzhuan; Liu, Yan; Wang, Xiaofen; Cui, Zongjun

2012-08-01

The microbial consortium WSD-5 is composed of bacteria and fungi, and the cooperation and symbiosis of the contained microbes enhance the degradation ability of WSD-5. Experiment results showed that the highest cellulase and hemicellulase were obtained when ventilation volume was 4 L/min, stirring rate was 0 rpm, and substrate loading rate was 3%. After 6 days of cultivation, a 67.60% loss in wheat straw dry weight was observed. The crude enzyme secreted from WSD-5 after optimization was evaluated by experiments of saccharification and acidification. The maximum concentration of reducing sugars was 3254 mg/L after 48 h saccharification. The concentration of sCOD peaked on day 2 with a value of 4345 mg/L during acidification, and the biogas yield and methane yield were 22.3% and 32.3% higher than un-acidified samples. This study is the first attempt to explore both the saccharification and the acidification ability of crude enzymes secreted by microbial consortium. Copyright © 2012 Elsevier Ltd. All rights reserved.

Assessment of integrated process based on hydrothermal and alkaline treatments for enzymatic saccharification of sweet sorghum stems.

PubMed

Sun, Shao-Long; Sun, Shao-Ni; Wen, Jia-Long; Zhang, Xue-Ming; Peng, Feng; Sun, Run-Cang

2015-01-01

In this study, sweet sorghum stem was subjected to hydrothermal pretreatment (HTP) and alkaline post-treatment to enhance its saccharification ratio by reducing its recalcitrance. The results showed that the HTP (110-210°C, 0.5-2.0h) significantly degraded hemicelluloses, and the pretreatment at the temperature higher than 190°C led to the partial degradation of the cellulose. As compared to the sole HTP, the integrated process removed most of lignin and hemicelluloses, which incurred a higher cellulose saccharification ratio. Under an optimum condition evaluated (HTP at 170°C for 0.5h and subsequent 2% NaOH treatment), 77.5% saccharification ratio was achieved, which was 1.8, 2.0 and 5.5 times as compared to the only HTP pretreated substrates, alkaline treated substrates alone and the raw material without pretreatment, respectively. Clearly, the integrated process can be considered as a promising approach to achieve an efficient conversion of lignocellulose to fermentable glucose. Copyright © 2014 Elsevier Ltd. All rights reserved.

Heterologous production of cellobiose dehydrogenases from the basidiomycete Coprinopsis cinerea and the ascomycete Podospora anserina and their effect on saccharification of wheat straw.

PubMed

Turbe-Doan, Annick; Arfi, Yonathan; Record, Eric; Estrada-Alvarado, Isabel; Levasseur, Anthony

2013-06-01

Cellobiose dehydrogenases (CDHs) are extracellular glycosylated haemoflavoenzymes produced by many different wood-degrading and phytopathogenic fungi. Putative cellobiose dehydrogenase genes are recurrently discovered by genome sequencing projects in various phylogenetically distinct fungi. The genomes from the basidiomycete Coprinopsis cinerea and the ascomycete Podospora anserina were screened for candidate cdh genes, and one and three putative gene models were evidenced, respectively. Two putative cdh genes were selected and successfully expressed for the first time in Aspergillus niger. CDH activity was measured for both constructions (CDHcc and CDHpa), and both recombinant CDHs were purified to homogeneity and subsequently characterised. Kinetic constants were determined for several carbohydrates including β-1,4-linked di- and oligosaccharides. Optimal temperature and pH were 60 °C and 5 for CDHcc and 65-70 °C and 6 for CDHpa. Both CDHs showed a broad range of pH stability between 4 and 8. The effect of both CDHs on saccharification of micronized wheat straw by an industrial Trichoderma reesei secretome was determined. The addition of each CDH systematically decreased the release of total reducing sugars, but to different extents and according to the CDH concentration. Analytical methods were carried out to quantify the release of glucose, xylose and gluconic acid. An increase of glucose and xylose was measured at a low CDHcc concentration. At moderated and high CDHcc and CDHpa concentrations, glucose was severely reduced with a concomitant increase of gluconic acid. In conclusion, these results give new insights into the physical and chemical parameters and diversity of basidiomycetous and ascomycetous CDHs. These findings also demonstrated that CDH drastically influenced the saccharification on a natural substrate, and thus, CDH origin, concentration and potential enzymatic partners should be carefully considered in future artificial secretomes for

Evaluation of High Throughput Screening Methods in Picking up Differences between Cultivars of Lignocellulosic Biomass for Ethanol Production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lindedam, Jane; Bruun, Sander; Jorgensen, Henning

2014-07-01

Here, we present a unique evaluation of three advanced high throughput pretreatment and enzymatic hydrolysis systems (HTPH-systems) for screening of lignocellulosic biomass for enzymatic saccharification. Straw from 20 cultivars of winter wheat from two sites in Denmark was hydrothermally pretreated and enzymatically processed in each of the separately engineered HTPH-systems at 1) University of California, Riverside, 2) National Renewable Energy Laboratory (NREL), Colorado, and 3) University of Copenhagen (CPH). All three systems were able to detect significant differences between the cultivars in the release of fermentable sugars, with average cellulose conversions of 57%, 64%, and 71% from Riverside, NREL andmore » CPH, respectively. We found the best correlation of glucose yields between the Riverside and NREL systems (R2 = 0.2139), and the best correlation for xylose yields was found between Riverside and CPH (R2 = 0.4269). The three systems identified Flair as the highest yielding cultivar and Dinosor, Glasgow, and Robigus as low yielding cultivars. Despite different conditions in the three HTPH-systems, the approach of microscale screening for phenotypically less recalcitrant feedstock seems sufficiently robust to be used as a generic analytical platform.« less

Understanding the effects of lignosulfonate on enzymatic saccharification of pure cellulose

Treesearch

Hongming Lou; Haifeng Zhou; Xiuli Li; Mengxia Wang; J.Y. Zhu; Xueqing Qiu

2014-01-01

The effects of lignosulfonate (LS) on enzymatic saccharification of pure cellulose were studied. Four fractions of LS with different molecular weight (MW) prepared by ultrafiltration of a commercial LS were applied at different loadings to enzymatic hydrolysis of Whatman paper under different pH. Using LS fractions with low MW and high degree of sulfonation can enhance...

Effects of drying-induced fiber hornification on enzymatic saccharification of lignocelluloses

Treesearch

Xiaolin Luo; Junyong Zhu

2011-01-01

This study investigated the effect of fiber hornification during drying on lignocellulosic substrate enzymatic saccharification. Two chemically pretreated wood substrates and one commercial bleached kraft hardwood pulp were used. Heat drying at 105 and 150°C and air drying at 50% RH and 23.8°C for different durations were applied to produce substrate...

Ethanosolv Pretreatment of Bamboo with Dilute Acid for Efficient Enzymatic Saccharification

Treesearch

Zhiqiang Li; Zehui Jiang; Benhua Fei; Zhiyong Cai; Xuejun Pan

2012-01-01

Bamboo is a potential lignocellulosic biomass for the production of bioethanol because of its high cellulose and hemicelluloses content. In this research, ethanosolv pretreatment catalyzed by sulfuric acid was studied in order to enhance enzymatic saccharification of moso bamboo. The addition of 2% (w/w on bamboo) sulfuric acid in water or 75% (v/v) ethanol was...

Thermophilic fungi as new sources for production of cellulases and xylanases with potential use in sugarcane bagasse saccharification.

PubMed

de Cassia Pereira, J; Paganini Marques, N; Rodrigues, A; Brito de Oliveira, T; Boscolo, M; da Silva, R; Gomes, E; Bocchini Martins, D A

2015-04-01

To obtain new cellulases and xylanases from thermophilic fungi; evaluate their potential for sugarcane bagasse saccharification. Thirty-two heat-tolerant fungi were isolated from the environment, identified (morphological/molecular tools) and the production of the enzymes was evaluated by solid state fermentation using lignocellulosic materials as substrates. Myceliophthora thermophila JCP 1-4 was the best producer of endoglucanase (357·51 U g(-1) ), β-glucosidase (45·42 U g(-1) ), xylanase (931·11 U g(-1) ) and avicelase (3·58 U g(-1) ). These enzymes were most active at 55-70°C and stable at 30-60°C. Using crude enzymatic extract from M. thermophila JCP 1-4 to saccharify sugarcane bagasse pretreated with microwaves and glycerol, glucose and xylose yields obtained were 15·6 and 35·13% (2·2 and 1·95 g l(-1) ), respectively. All isolated fungi have potential to produce the enzymes; M. thermophila JCP 1-4 enzymatic extract have potential to be better explored in saccharification experiments. Pretreatment improved enzymatic saccharification, as sugar yields were much higher than those obtained from in natura bagasse. Myceliophthora thermophila JCP 1-4 produces avicelase (not commonly found among fungi; important to hydrolyse crystalline cellulose) and a β-glucosidase resistant to glucose inhibition, interesting characteristics for saccharification experiments. © 2015 The Society for Applied Microbiology.

Effects of wet-pressing-induced fiber hornification on enzymatic saccharification of lignocelluloses

Treesearch

X.L. Luo; Junyong Zhu; Roland Gleisner; H.Y. Zhan

2011-01-01

This article reports the effect of wet-pressing-induced fiber hornification on enzymatic saccharification of lignocelluloses. A wet cellulosic substrate of bleached kraft eucalyptus pulp and two wet sulfite-pretreated lignocellulosic substrates of aspen and lodgepole pine were pressed to various moisture (solids) contents by variation of pressing pressure and pressing...

Alkaline peroxide pretreatment of corn stover for enzymatic saccharification and ethanol production

USDA-ARS?s Scientific Manuscript database

Alkaline hydrogen peroxide (AHP) pretreatment and enzymatic saccharification were evaluated for conversion of corn stover cellulose and hemicellulose to fermentable sugars. Corn stover used in this study contained 37.0±0.2% cellulose, 26.8±0.2% hemicellulose and 18.0±0.1% lignin on dry basis. Unde...

Ethanol production via simultaneous saccharification and fermentation of sodium hydroxide treated corn stover using Phanerochaete chrysosporium and Gloeophyllum trabeum.

PubMed

Vincent, Micky; Pometto, Anthony L; van Leeuwen, J Hans

2014-04-01

Ethanol was produced via the simultaneous saccharification and fermentation (SSF) of dilute sodium hydroxide treated corn stover. Saccharification was achieved by cultivating either Phanerochaete chrysosporium or Gloeophyllum trabeum on the treated stover, and fermentation was then performed by using either Saccharomyces cerevisiae or Escherichia coli K011. Ethanol production was highest on day 3 for the combination of G. trabeum and E. coli K011 at 6.68 g/100g stover, followed by the combination of P. chrysosporium and E. coli K011 at 5.00 g/100g stover. SSF with S. cerevisiae had lower ethanol yields, ranging between 2.88 g/100g stover at day 3 (P. chrysosporium treated stover) and 3.09 g/100g stover at day 4 (G. trabeum treated stover). The results indicated that mild alkaline pretreatment coupled with fungal saccharification offers a promising bioprocess for ethanol production from corn stover without the addition of commercial enzymes. Published by Elsevier Ltd.

Xylanase supplementation on enzymatic saccharification of dilute acid pretreated poplars at different severities

Treesearch

Chao Zhang; Xinshu Zhuang; Zhao Jiang Wang; Fred Matt; Franz St. John; J.Y. Zhu

2013-01-01

Three pairs of solid substrates from dilute acid pretreatment of two poplar wood samples were enzymatically hydrolyzed by cellulase preparations supplemented with xylanase. Supplementation of xylanase improved cellulose saccharification perhaps due to improved cellulose accessibility by xylan hydrolysis. Total xylan removal directly affected enzymatic cellulose...

Simultaneous saccharification and fermentation of industrial sweetpotatoes for ethanol production and anthocyanins extraction

USDA-ARS?s Scientific Manuscript database

A simultaneous saccharification fermentation (SSF) system was studied for ethanol production in flour industrial sweetpotato (ISP) feedstocks (lines: white DM02-180 and purple NC-413) as an integrated cost saving process, and to examine the feasibility of extracting anthocyanins from flour purple IS...

Empirical evaluation of inhibitory product, substrate, and enzyme effects during the enzymatic saccharification of lignocellulosic biomass.

PubMed

Smith, Benjamin T; Knutsen, Jeffrey S; Davis, Robert H

2010-05-01

The cellulose hydrolysis kinetics during batch enzymatic saccharification are typified by a rapid initial rate that subsequently decays, resulting in incomplete conversion. Previous studies suggest that changes associated with the solution, substrate, or enzymes may be responsible. In this work, kinetic experiments were conducted to determine the relative magnitude of these effects. Pretreated corn stover (PCS) was used as a lignocellulosic substrate likely to be found in a commercial saccharification process, while Avicel and Kraft lignin were used to create model substrates. Glucose inhibition was observed by spiking the reaction slurry with glucose during initial-rate experiments. Increasing the glucose concentration from 7 to 48 g/L reduced the cellulose conversion rate by 94%. When product sugars were removed using ultrafiltration with a 10 kDa membrane, the glucose-based conversion increased by 9.5%. Reductions in substrate reactivity with conversion were compared directly by saccharifying PCS and Avicel substrates that had been pre-reacted to different conversions. Reaction of substrate with a pre-conversion of 40% resulted in about 40% reduction in the initial rate of saccharification, relative to fresh substrate with identical cellulose concentration. Overall, glucose inhibition and reduced substrate reactivity appear to be dominant factors, whereas minimal reductions of enzyme activity were observed.

Liquid nitrogen pretreatment of eucalyptus sawdust and rice hull for enhanced enzymatic saccharification.

PubMed

Castoldi, Rafael; Correa, Vanesa G; de Morais, Gutierrez Rodrigues; de Souza, Cristina G M; Bracht, Adelar; Peralta, Rosely A; Peralta-Muniz Moreira, Regina F; Peralta, Rosane M

2017-01-01

In this work, liquid nitrogen was used for the first time in the pretreatment of plant biomasses for purposes of enzymatic saccharification. After treatment (cryocrushing), the initial rates of the enzymatic hydrolysis of eucalyptus sawdust and rice hull were increased more than ten-fold. Cryocrushing did not modify significantly the contents of cellulose, hemicellulose and lignin in both eucalyptus sawdust and rice hulls. However, substantial disorganization of the lignocellulosic materials in consequence of the pretreatment could be observed by electron microscopy. Cryocrushing was highly efficient in improving the saccharification of the holocellulose component of the plant biomasses (from 4.3% to 54.1% for eucalyptus sawdust and from 3.9% to 40.6% for rice hull). It is important to emphasize that it consists in a simple operation with low requirements of water and chemicals, no corrosion, no release of products such as soluble phenolics, furfural and hydroxymethylfurfural and no waste generation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Short time ionic liquids pretreatment on lignocellulosic biomass to enhance enzymatic saccharification.

PubMed

Uju; Shoda, Yasuhiro; Nakamoto, Aya; Goto, Masahiro; Tokuhara, Wataru; Noritake, Yoshiyuki; Katahira, Satoshi; Ishida, Nobuhiro; Nakashima, Kazunori; Ogino, Chiaki; Kamiya, Noriho

2012-01-01

The potential of 1-buthyl-3-methylpyridinium chloride, [Bmpy][Cl], as a pretreatment solvent for lignocellulosic biomasses, Bagasse and Eucalyptus, was investigated. The yields of regenerated biomasses ranged between 35% and 96%, and varied according to the pretreatment time, type of ionic liquid (IL) and biomass. The pretreatment of the biomass with [Bmpy][Cl] resulted in up to 8-fold increase in the cellulose conversion when compared with the untreated biomass. For a short pretreatment period (i.e., 10 min), [Bmpy][Cl] showed better performance than 1-ethyl-3-methylimidazolium acetate ([Emim][OAc]) with respect to the initial enzymatic saccharification rates. The increase in the reaction rates with [Emim][OAc] treatment was because of a reduction in the cellulose crystallinity. In contrast, a decrease in the crystallinity index was not clearly observed for the biomass pretreated with [Bmpy][Cl], and the enhancement of the enzymatic saccharification rates using this IL is presumably due to a reduction in the degree of polymerization of cellulose in the biomass. Copyright © 2011. Published by Elsevier Ltd.

Improved in situ saccharification of cellulose pretreated by dimethyl sulfoxide/ionic liquid using cellulase from a newly isolated Paenibacillus sp. LLZ1.

PubMed

Hu, Dongxue; Ju, Xin; Li, Liangzhi; Hu, Cuiying; Yan, Lishi; Wu, Tianyun; Fu, Jiaolong; Qin, Ming

2016-02-01

A cellulase producing strain was newly isolated from soil samples and identified as Paenibacillus sp. LLZ1. A novel aqueous-dimethyl sulfoxide (DMSO)/1-ethyl-3-methylimidazolium diethyl phosphate ([Emin]DEP)-cellulase system was designed and optimized. In the pretreatment, DMSO was found to be a low-cost substitute of up to 70% ionic liquid to enhance the cellulose dissolution. In the enzymatic saccharification, the optimum pH and temperature of the Paenibacillus sp. LLZ1 cellulase were identified as 6.0 and 40°C, respectively. Under the optimized reaction condition, the conversion of microcrystalline cellulose and bagasse cellulose increased by 39.3% and 37.6%, compared with unpretreated cellulose. Compared to current methods of saccharification, this new approach has several advantages including lower operating temperature, milder pH, and less usage of ionic liquid, indicating a marked progress in environmental friendly hydrolysis of biomass-based materials. Copyright © 2015 Elsevier Ltd. All rights reserved.

Characterization of cellulolytic extract from Pycnoporus sanguineus PF-2 and its application in biomass saccharification.

PubMed

Falkoski, Daniel Luciano; Guimarães, Valéria Monteze; de Almeida, Maíra Nicolau; Alfenas, Acelino Couto; Colodette, Jorge Luiz; de Rezende, Sebastião Tavares

2012-03-01

The aim of this work was to evaluate the biochemical features of the white-rot fungi Pycnoporus sanguineus cellulolytic complex and its utilization to sugarcane bagasse hydrolysis. When cultivated under submerged fermentation using corn cobs as carbon source, P. sanguineus produced high FPase, endoglucanase, β-glucosidase, xylanase, mannanase, α-galactosidase, α-arabinofuranosidase, and polygalacturonase activities. Cellulase activities were characterized in relation to pH and temperature. β-Glucosidase and FPase activities were higher at 55 °C, pH 4.5, and endoglucanase activity was higher at 60 °C, in a pH range of 3.5-4.0. All cellulase activities were highly stable at 40 and 50 °C through 48 h of pre-incubation. Crude enzymatic extract from P. sanguineus was applied in a saccharification experiment using acid-treated and alkali-treated sugarcane bagasse as substrate, and the hydrolysis yields were compared to that obtained by a commercial cellulase preparation. Reducing sugar yields of 60.4% and 64.0% were reached when alkali-treated bagasse was hydrolyzed by P. sanguineus extract and commercial cellulase, respectively. Considering the glucose production, it was observed that P. sanguineus extract and commercial cellulase ensured yields of 22.6% and 36.5%, respectively. The saccharification of acid-treated bagasse was lower than that of alkali-treated bagasse regardless of the cellulolytic extract. The present work showed that P. sanguineus has a great potential as an enzyme producer for biomass saccharification.

Simultaneous saccharification and fermentation of acid-pretreated rapeseed meal for succinic acid production using Actinobacillus succinogenes.

PubMed

Chen, Kequan; Zhang, Han; Miao, Yelian; Wei, Ping; Chen, Jieyu

2011-04-07

Rapeseed meal was evaluated for succinic acid production by simultaneous saccharification and fermentation using Actinobacillus succinogenes ATCC 55618. Diluted sulfuric acid pretreatment and subsequent hydrolysis with pectinase was used to release sugars from rapeseed meal. The effects of culture pH, pectinase loading and yeast extract concentration on succinic acid production were investigated. When simultaneous saccharification and fermentation of diluted acid pretreated rapeseed meal with a dry matter content of 12.5% (w/v) was performed at pH 6.4 and a pectinase loading of 2% (w/w, on dry matter) without supplementation of yeast extract, a succinic acid concentration of 15.5 g/L was obtained at a yield of 12.4 g/100g dry matter. Fed-batch simultaneous saccharification and fermentation was carried out with supplementation of concentrated pretreated rapeseed meal and pectinase at 18 and 28 h to yield a final dry matter content of 20.5% and pectinase loading of 2%, with the succinic acid concentration enhanced to 23.4 g/L at a yield of 11.5 g/100g dry matter and a productivity of 0.33 g/(Lh). This study suggests that rapeseed meal may be an alternative substrate for the efficient production of succinic acid by A. succinogenes without requiring nitrogen source supplementation. Copyright © 2011 Elsevier Inc. All rights reserved.

The simultaneous saccharification and fermentation of pretreated woody crops to ethanol

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spindler, D.D.; Wyman, C.E.; Grohmann, K.

1991-12-31

Four promising woody crops (Populus maximowiczii x nigra (NE388), P. trichocarpa x deltoides (N11), P. tremuloides, and Sweetgum Liquidambar styraciflua) were pretreated by dilute sulfuric acid and evaluated in the simultaneous saccharification and fermentation (SSF) process for ethanol production. The yeast Saccharomyces cerevisiae was used in the fermentations alone, and in mixed cultures with {beta}-glucosidase producing Brettanomyces clausenii. Commercial Genencor 150L cellulose enyme was either employed alone or supplemented with {beta}-glucosidase. All SSFs were run at 37{degrees}C for 8 d and compared to saccharifications at 45{degrees}C under the same enzyme loadings. S. cerevisiae alone achieved the highest ethanol yields andmore » rates of hydrolysis at the higher enzyme loadings, whereas the mixed culture performed better at the lower enzyme loadings without {beta}-glucosidase supplementation. The best overall rates of fermentation (3 d) and final theoretical ethanol yields (86-90%) were achieved with P. maximowiczii x nigra (NE388) and Sweetgum Liquidambar styraciflua, followed by P. tremuloides and P. trichocarpa x deltoides (N11) with slightly slower rates and lower yields. Although there were some differences in SSF performance, all these pretreated woody crops show promise as substrates for ethanol production.« less

Production of D-lactic acid from defatted rice bran by simultaneous saccharification and fermentation.

PubMed

Tanaka, Takaaki; Hoshina, Masahiro; Tanabe, Suguru; Sakai, Kenji; Ohtsubo, Sadami; Taniguchi, Masayuki

2006-01-01

Production of d-lactic acid from rice bran, one of the most abundant agricultural by-products in Japan, is studied. Lactobacillus delbrueckii subsp. delbrueckii IFO 3202 and defatted rice bran powder after squeezing rice oil were used for the production. Since the rice bran contains polysaccharides as starch and cellulose, we coupled saccharification with amylase and cellulase to lactic acid fermentation. The indigenous bacteria in the rice bran produced racemic lactic acid in the saccharification at pH 6.0-6.8. Thus the pH was controlled at 5.0 to suppress the growth of the indigenous bacteria. L. delbrueckii IFO 3202 produced 28 kgm(-3) lactic acid from 100 kgm(-3) rice bran after 36 h at 37 degrees C. The yield based on the amount of sugars soluble after 36-h hydrolysis of the bran by amylase and cellulase (36 kgm(-3) from 100 kgm(-3) of the bran) was 78%. The optical purity of produced d-lactic acid was 95% e.e.

Addition of alkali to the hydrothermal-mechanochemical treatment of Eucalyptus enhances its enzymatic saccharification.

PubMed

Ishiguro, Maki; Endo, Takashi

2014-02-01

The effects of alkali on hydrothermal-mechanochemical treatment (hydrothermal treatment combined with wet-milling) were examined with the aim of improving pretreatment of lignocellulosic biomass before enzymatic saccharification. After enzymatic saccharification, the highest glucose yield was obtained by autoclaving at 170°C in the presence of 20% NaOH per substrate weight. The wood fiber was unraveled into finer nanofibers by hydrothermal-mechanochemical treatment, thus increasing the specific surface area of the substrate from 11 to 132m(2)/g. Adding 20% NaOH to the treatment further increased the specific surface area of the already fibrillated substrate by 76% (232m(2)/g) due to lignin removal and ester bond cleavage between lignin and hemicellulose. This increase in specific surface area was closely related to the increase in enzymatic digestibility; therefore, NaOH addition may have enhanced the effect of hydrothermal-mechanochemical treatment. Copyright © 2013 Elsevier Ltd. All rights reserved.

Lignosulfonate To Enhance Enzymatic Saccharification of Lignocelluloses: Role of Molecular Weight and Substrate Lignin

Treesearch

Haifeng Zhou; Hongming Lou; Dongjie Yang; J.Y. Zhu; Xueqing Qiu

2013-01-01

This study conducted an investigation of the effect of lignosulfonate (LS) on enzymatic saccharification of lignocelluloses. Two commercial LSs and one laboratory sulfonated kraft lignin were applied to Whatman paper, dilute acid and SPORL (sulfite pretreatment to overcome recalcitrance of lignocelluloses) pretreated aspen, and kraft alkaline and SPORL pretreated...

Mild chemical pretreatments are sufficient for complete saccharification of steam-exploded residues and high ethanol production in desirable wheat accessions.

PubMed

Zahoor; Tu, Yuanyuan; Wang, Lingqiang; Xia, Tao; Sun, Dan; Zhou, Shiguang; Wang, Yanting; Li, Ying; Zhang, Heping; Zhang, Tong; Madadi, Meysam; Peng, Liangcai

2017-11-01

In this study, a combined pretreatment was performed in four wheat accessions using steam explosion followed with different concentrations of H 2 SO 4 or NaOH, leading to increased hexoses yields by 3-6 folds from enzymatic hydrolysis. Further co-supplied with 1% Tween-80, Talq90 and Talq16 accessions exhibited an almost complete enzymatic saccharification of steam-exploded (SE) residues after 0.5% H 2 SO 4 or 1% NaOH pretreatment, with the highest bioethanol yields at 18.5%-19.4%, compared with previous reports about wheat bioethanol yields at 11%-17% obtained under relatively strong pretreatment conditions. Furthermore, chemical analysis indicated that much enhanced saccharification in Talq90 and Talq16 may be partially due to their relatively low cellulose CrI and DP values and high hemicellulose Ara and H-monomer levels in raw materials and SE residues. Hence, this study has not only demonstrated a mild pretreatment technology for a complete saccharification, but it has also obtained the high ethanol production in desirable wheat accessions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Fungal cellulases as an aid for the saccharification of cassava

DOE Office of Scientific and Technical Information (OSTI.GOV)

De Menezes, T.J.B.; Arakaki, T.; DeLamo, P.R.

1978-01-01

Culture broths of cellulolytic fungi were used together with commercial amylases to enhance the saccharification of cassava starch slurry. The addition of appropriate concentration of cellulase from Trichoderma viride and from a basidiomycete from soil increased both the rate of sugar formation and the degree of solubilization and decreased the viscosity of the hydrolyzates. Owing to the improvement of the rhetorical properties of the must and the additional sugar produced, an increased ethanol yield would be expected from the alcohol fermentation of this hydrolyzate.

Pipeline transport and simultaneous saccharification of corn stover.

PubMed

Kumar, Amit; Cameron, Jay B; Flynn, Peter C

2005-05-01

Pipeline transport of corn stover delivered by truck from the field is evaluated against a range of truck transport costs. Corn stover transported by pipeline at 20% solids concentration (wet basis) or higher could directly enter an ethanol fermentation plant, and hence the investment in the pipeline inlet end processing facilities displaces comparable investment in the plant. At 20% solids, pipeline transport of corn stover costs less than trucking at capacities in excess of 1.4 M drytonnes/yr when compared to a mid range of truck transport cost (excluding any credit for economies of scale achieved in the ethanol fermentation plant from larger scale due to multiple pipelines). Pipelining of corn stover gives the opportunity to conduct simultaneous transport and saccharification (STS). If current enzymes are used, this would require elevated temperature. Heating of the slurry for STS, which in a fermentation plant is achieved from waste heat, is a significant cost element (more than 5 cents/l of ethanol) if done at the pipeline inlet unless waste heat is available, for example from an electric power plant located adjacent to the pipeline inlet. Heat loss in a 1.26 m pipeline carrying 2 M drytonnes/yr is about 5 degrees C at a distance of 400 km in typical prairie clay soils, and would not likely require insulation; smaller pipelines or different soil conditions might require insulation for STS. Saccharification in the pipeline would reduce the need for investment in the fermentation plant, saving about 0.2 cents/l of ethanol. Transport of corn stover in multiple pipelines offers the opportunity to develop a large ethanol fermentation plant, avoiding some of the diseconomies of scale that arise from smaller plants whose capacities are limited by issues of truck congestion.

Starch saccharification and fermentation of uncooked sweet potato roots for fuel ethanol production.

PubMed

Zhang, Peng; Chen, Caifa; Shen, Yanhu; Ding, Tielin; Ma, Daifu; Hua, Zichun; Sun, Dongxu

2013-01-01

An energy-saving ethanol fermentation technology was developed using uncooked fresh sweet potato as raw material. A mutant strain of Aspergillus niger isolated from mildewed sweet potato was used to produce abundant raw starch saccharification enzymes for treating uncooked sweet potato storage roots. The viscosity of the fermentation paste of uncooked sweet potato roots was lower than that of the cooked roots. The ethanol fermentation was carried out by Zymomonas mobilis, and 14.4 g of ethanol (87.2% of the theoretical yield) was produced from 100g of fresh sweet potato storage roots. Based on this method, an energy-saving, high efficient and environment-friendly technology can be developed for large-scale production of fuel ethanol from sweet potato roots. Copyright © 2012 Elsevier Ltd. All rights reserved.

Comparison of Dilute Acid and Ionic Liquid Pretreatment of Switchgrass: Biomass Recalcitrance, Delignification and Enzymatic Saccharification

USDA-ARS?s Scientific Manuscript database

The efficiency of two biomass pretreatment technologies, dilute acid hydrolysis and dissolution in an ionic liquid, are compared in terms of delignification, saccharification efficiency and saccharide yields with switchgrass serving as a model bioenergy crop. When subject to ionic liquid pretreatme...

Kinetic modeling of multi-feed simultaneous saccharification and co-fermentation of pretreated birch to ethanol.

PubMed

Wang, Ruifei; Koppram, Rakesh; Olsson, Lisbeth; Franzén, Carl Johan

2014-11-01

Fed-batch simultaneous saccharification and fermentation (SSF) is a feasible option for bioethanol production from lignocellulosic raw materials at high substrate concentrations. In this work, a segregated kinetic model was developed for simulation of fed-batch simultaneous saccharification and co-fermentation (SSCF) of steam-pretreated birch, using substrate, enzymes and cell feeds. The model takes into account the dynamics of the cellulase-cellulose system and the cell population during SSCF, and the effects of pre-cultivation of yeast cells on fermentation performance. The model was cross-validated against experiments using different feed schemes. It could predict fermentation performance and explain observed differences between measured total yeast cells and dividing cells very well. The reproducibility of the experiments and the cell viability were significantly better in fed-batch than in batch SSCF at 15% and 20% total WIS contents. The model can be used for simulation of fed-batch SSCF and optimization of feed profiles. Copyright © 2014 Elsevier Ltd. All rights reserved.

Chemical Pretreatment-Independent Saccharifications of Xylan and Cellulose of Rice Straw by Bacterial Weak Lignin-Binding Xylanolytic and Cellulolytic Enzymes

PubMed Central

Teeravivattanakit, Thitiporn; Baramee, Sirilak; Phitsuwan, Paripok; Sornyotha, Somphit; Waeonukul, Rattiya; Pason, Patthra; Tachaapaikoon, Chakrit; Poomputsa, Kanokwan; Kosugi, Akihiko; Sakka, Kazuo

2017-01-01

. It demonstrates efficient synergism with endoxylanases PcXyn10C and PcXyn11A to depolymerize xylan in untreated rice straw and enhanced the xylose production and improved cellulose hydrolysis. Therefore, it can be considered an enzymatic pretreatment. Furthermore, the studies here show that glucose yield released from steam- and xylanolytic enzyme-treated rice straw by the combination of CtCel9R and TbCglT was higher than the glucose yield obtained from ammonia-treated rice straw saccharification. This work presents a novel environment-friendly xylanolytic enzyme pretreatment not only as a green pretreatment but also as an economically feasible biorefinery method. PMID:28864653

Chemical Pretreatment-Independent Saccharifications of Xylan and Cellulose of Rice Straw by Bacterial Weak Lignin-Binding Xylanolytic and Cellulolytic Enzymes.

PubMed

Teeravivattanakit, Thitiporn; Baramee, Sirilak; Phitsuwan, Paripok; Sornyotha, Somphit; Waeonukul, Rattiya; Pason, Patthra; Tachaapaikoon, Chakrit; Poomputsa, Kanokwan; Kosugi, Akihiko; Sakka, Kazuo; Ratanakhanokchai, Khanok

2017-11-15

demonstrates efficient synergism with endoxylanases PcXyn10C and PcXyn11A to depolymerize xylan in untreated rice straw and enhanced the xylose production and improved cellulose hydrolysis. Therefore, it can be considered an enzymatic pretreatment. Furthermore, the studies here show that glucose yield released from steam- and xylanolytic enzyme-treated rice straw by the combination of CtCel9R and TbCglT was higher than the glucose yield obtained from ammonia-treated rice straw saccharification. This work presents a novel environment-friendly xylanolytic enzyme pretreatment not only as a green pretreatment but also as an economically feasible biorefinery method. Copyright © 2017 American Society for Microbiology.

Enhanced enzymatic saccharification of pretreated biomass using glycerol thermal processing (GTP).

PubMed

Zhang, Wei; Sathitsuksanoh, Noppadon; Barone, Justin R; Renneckar, Scott

2016-01-01

Biomass was heated (200-240°C) in the presence of glycerol, for 4-12 min, under shear to disrupt the native cell wall architecture. The impact of this method, named glycerol thermal processing (GTP), on saccharification efficiency of the hardwood Liquidambar styraciflua, and a control cellulose sample was studied as a function of treatment severity. Furthermore, the enzymatic conversion of samples with varying compositions was studied after extraction of the structural polymers. Interestingly, the sweet gum processed materials crystallinity index increased by 10% of the initial value. The experiments revealed that the residual lignin was not a barrier to limiting the digestibility of cellulose after pretreatment yielding up to 70% glucose based on the starting wood material. Further xylan removal greatly improved the cellulose hydrolysis rate, converting nearly 70% of the cellulose into glucose within 24h, and reaching 78% of ultimate glucan digestibility after 72 h. Copyright © 2015 Elsevier Ltd. All rights reserved.

Simultaneous Saccharification and Fermentation of Sugar Beet Pulp for Efficient Bioethanol Production

PubMed Central

Berłowska, Joanna; Balcerek, Maria; Dziekońska-Kubczak, Urszula; Patelski, Piotr; Dziugan, Piotr

2016-01-01

Sugar beet pulp, a byproduct of sugar beet processing, can be used as a feedstock in second-generation ethanol production. The objective of this study was to investigate the effects of pretreatment, of the dosage of cellulase and hemicellulase enzyme preparations used, and of aeration on the release of fermentable sugars and ethanol yield during simultaneous saccharification and fermentation (SSF) of sugar beet pulp-based worts. Pressure-thermal pretreatment was applied to sugar beet pulp suspended in 2% w/w sulphuric acid solution at a ratio providing 12% dry matter. Enzymatic hydrolysis was conducted using Viscozyme and Ultraflo Max (Novozymes) enzyme preparations (0.015–0.02 mL/g dry matter). Two yeast strains were used for fermentation: Ethanol Red (S. cerevisiae) (1 g/L) and Pichia stipitis (0.5 g/L), applied sequentially. The results show that efficient simultaneous saccharification and fermentation of sugar beet pulp was achieved. A 6 h interval for enzymatic activation between the application of enzyme preparations and inoculation with Ethanol Red further improved the fermentation performance, with the highest ethanol concentration reaching 26.9 ± 1.2 g/L and 86.5 ± 2.1% fermentation efficiency relative to the theoretical yield. PMID:27722169

Simultaneous Saccharification and Fermentation of Sugar Beet Pulp for Efficient Bioethanol Production.

PubMed

Berłowska, Joanna; Pielech-Przybylska, Katarzyna; Balcerek, Maria; Dziekońska-Kubczak, Urszula; Patelski, Piotr; Dziugan, Piotr; Kręgiel, Dorota

2016-01-01

Sugar beet pulp, a byproduct of sugar beet processing, can be used as a feedstock in second-generation ethanol production. The objective of this study was to investigate the effects of pretreatment, of the dosage of cellulase and hemicellulase enzyme preparations used, and of aeration on the release of fermentable sugars and ethanol yield during simultaneous saccharification and fermentation (SSF) of sugar beet pulp-based worts. Pressure-thermal pretreatment was applied to sugar beet pulp suspended in 2% w/w sulphuric acid solution at a ratio providing 12% dry matter. Enzymatic hydrolysis was conducted using Viscozyme and Ultraflo Max (Novozymes) enzyme preparations (0.015-0.02 mL/g dry matter). Two yeast strains were used for fermentation: Ethanol Red ( S. cerevisiae ) (1 g/L) and Pichia stipitis (0.5 g/L), applied sequentially. The results show that efficient simultaneous saccharification and fermentation of sugar beet pulp was achieved. A 6 h interval for enzymatic activation between the application of enzyme preparations and inoculation with Ethanol Red further improved the fermentation performance, with the highest ethanol concentration reaching 26.9 ± 1.2 g/L and 86.5 ± 2.1% fermentation efficiency relative to the theoretical yield.

Evaluation of a standard test method for screening fuels in soils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sorini, S.S.; Schabron, J.F.

1996-12-31

A new screening method for fuel contamination in soils was recently developed as American Society for Testing and Materials (ASTM) Method D-5831-95, Standard Test Method for Screening Fuels in Soils. This method uses low-toxicity chemicals and can be sued to screen organic- rich soils, as well as being fast, easy, and inexpensive to perform. Fuels containing aromatic compounds, such as diesel fuel and gasoline, as well as other aromatic-containing hydrocarbon materials, such as motor oil, crude oil, and cola oil, can be determined. The screening method for fuels in soils was evaluated by conducting a Collaborative study on the method.more » In the Collaborative study, a sand and an organic soil spiked with various concentrations of diesel fuel were tested. Data from the Collaborative study were used to determine the reproducibility (between participants) and repeatability (within participants) precision of the method for screening the test materials. The Collaborative study data also provide information on the performance of portable field equipment (patent pending) versus laboratory equipment for performing the screening method and a comparison of diesel concentration values determined using the screening method versus a laboratory method.« less

Engineering a highly active thermophilic β-glucosidase to enhance its pH stability and saccharification performance.

PubMed

Xia, Wei; Xu, Xinxin; Qian, Lichun; Shi, Pengjun; Bai, Yingguo; Luo, Huiying; Ma, Rui; Yao, Bin

2016-01-01

β-Glucosidase is an important member of the biomass-degrading enzyme system, and plays vital roles in enzymatic saccharification for biofuels production. Candidates with high activity and great stability over high temperature and varied pHs are always preferred in industrial practice. To achieve cost-effective biomass conversion, exploring natural enzymes, developing high level expression systems and engineering superior mutants are effective approaches commonly used. A newly identified β-glucosidase of GH3, Bgl3A, from Talaromyces leycettanus JCM12802, was overexpressed in yeast strain Pichia pastoris GS115, yielding a crude enzyme activity of 6000 U/ml in a 3 L fermentation tank. The purified enzyme exhibited outstanding enzymatic properties, including favorable temperature and pH optima (75 °C and pH 4.5), good thermostability (maintaining stable at 60 °C), and high catalytic performance (with a specific activity and catalytic efficiency of 905 U/mg and 9096/s/mM on pNPG, respectively). However, the narrow stability of Bgl3A at pH 4.0-5.0 would limit its industrial applications. Further site-directed mutagenesis indicated the role of excessive O-glycosylation in pH liability. By removing the potential O-glycosylation sites, two mutants showed improved pH stability over a broader pH range (3.0-10.0). Besides, with better stability under pH 5.0 and 50 °C compared with wild type Bgl3A, saccharification efficiency of mutant M1 was improved substantially cooperating with cellulase Celluclast 1.5L. And mutant M1 reached approximately equivalent saccharification performance to commercial β-glucosidase Novozyme 188 with identical β-glucosidase activity, suggesting its great prospect in biofuels production. In this study, we overexpressed a novel β-glucosidase Bgl3A with high specific activity and high catalytic efficiency in P. pastoris. We further proved the negative effect of excessive O-glycosylation on the pH stability of Bgl3A, and enhanced the p

Epigallocatechin gallate incorporation into lignin enhances the alkaline delignification and enzymatic saccharification of cell walls

PubMed Central

2012-01-01

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. PMID:22889353

Enhancing saccharification of wheat straw by mixing enzymes from genetically-modified Trichoderma reesei and Aspergillus niger.

PubMed

Jiang, Yanping; Duarte, Alexandra Vivas; van den Brink, Joost; Wiebenga, Ad; Zou, Gen; Wang, Chengshu; de Vries, Ronald P; Zhou, Zhihua; Benoit, Isabelle

2016-01-01

To increase the efficiency of enzymatic hydrolysis for plant biomass conversion into renewable biofuel and chemicals. By overexpressing the point mutation A824 V transcriptional activator Xyr1 in Trichoderma reesei, carboxymethyl cellulase, cellobiosidase and β-D-glucosidase activities of the best mutant were increased from 1.8 IU/ml, 0.1 IU/ml and 0.05 IU/ml to 4.8 IU/ml, 0.4 IU/ml and 0.3 IU/ml, respectively. The sugar yield of wheat straw saccharification by combining enzymes from this mutant and the Aspergillus niger genetically modified strain ΔcreA/xlnR c/araR c was improved up to 7.5 mg/ml, a 229 % increase compared to the combination of wild type strains. Mixing enzymes from T. reesei and A. niger combined with the genetic modification of transcription factors is a promising strategy to increase saccharification efficiency.

Disrupting the cinnamyl alcohol dehydrogenase 1 gene (BdCAD1) leads to altered lignification and improved saccharification in Brachypodium distachyon.

PubMed

Bouvier d'Yvoire, Madeleine; Bouchabke-Coussa, Oumaya; Voorend, Wannes; Antelme, Sébastien; Cézard, Laurent; Legée, Frédéric; Lebris, Philippe; Legay, Sylvain; Whitehead, Caragh; McQueen-Mason, Simon J; Gomez, Leonardo D; Jouanin, Lise; Lapierre, Catherine; Sibout, Richard

2013-02-01

Brachypodium distachyon (Brachypodium) has been proposed as a model for grasses, but there is limited knowledge regarding its lignins and no data on lignin-related mutants. The cinnamyl alcohol dehydrogenase (CAD) genes involved in lignification are promising targets to improve the cellulose-to-ethanol conversion process. Down-regulation of CAD often induces a reddish coloration of lignified tissues. Based on this observation, we screened a chemically induced population of Brachypodium mutants (Bd21-3 background) for red culm coloration. We identified two mutants (Bd4179 and Bd7591), with mutations in the BdCAD1 gene. The mature stems of these mutants displayed reduced CAD activity and lower lignin content. Their lignins were enriched in 8-O-4- and 4-O-5-coupled sinapaldehyde units, as well as resistant inter-unit bonds and free phenolic groups. By contrast, there was no increase in coniferaldehyde end groups. Moreover, the amount of sinapic acid ester-linked to cell walls was measured for the first time in a lignin-related CAD grass mutant. Functional complementation of the Bd4179 mutant with the wild-type BdCAD1 allele restored the wild-type phenotype and lignification. Saccharification assays revealed that Bd4179 and Bd7591 lines were more susceptible to enzymatic hydrolysis than wild-type plants. Here, we have demonstrated that BdCAD1 is involved in lignification of Brachypodium. We have shown that a single nucleotide change in BdCAD1 reduces the lignin level and increases the degree of branching of lignins through incorporation of sinapaldehyde. These changes make saccharification of cells walls pre-treated with alkaline easier without compromising plant growth. © 2012 The Authors The Plant Journal © 2012 Blackwell Publishing Ltd.

Rational Methods for the Selection of Diverse Screening Compounds

PubMed Central

Huggins, David J.; Venkitaraman, Ashok R.; Spring, David R.

2016-01-01

Traditionally a pursuit of large pharmaceutical companies, high-throughput screening assays are becoming increasingly common within academic and government laboratories. This shift has been instrumental in enabling projects that have not been commercially viable, such as chemical probe discovery and screening against high risk targets. Once an assay has been prepared and validated, it must be fed with screening compounds. Crafting a successful collection of small molecules for screening poses a significant challenge. An optimized collection will minimize false positives whilst maximizing hit rates of compounds that are amenable to lead generation and optimization. Without due consideration of the relevant protein targets and the downstream screening assays, compound filtering and selection can fail to explore the great extent of chemical diversity and eschew valuable novelty. Herein, we discuss the different factors to be considered and methods that may be employed when assembling a structurally diverse compound screening collection. Rational methods for selecting diverse chemical libraries are essential for their effective use in high-throughput screens. PMID:21261294

High-throughput Screening of Recalcitrance Variations in Lignocellulosic Biomass: Total Lignin, Lignin Monomers, and Enzymatic Sugar Release

PubMed Central

Decker, Stephen R.; Sykes, Robert W.; Turner, Geoffrey B.; Lupoi, Jason S.; Doepkke, Crissa; Tucker, Melvin P.; Schuster, Logan A.; Mazza, Kimberly; Himmel, Michael E.; Davis, Mark F.; Gjersing, Erica

2015-01-01

The conversion of lignocellulosic biomass to fuels, chemicals, and other commodities has been explored as one possible pathway toward reductions in the use of non-renewable energy sources. In order to identify which plants, out of a diverse pool, have the desired chemical traits for downstream applications, attributes, such as cellulose and lignin content, or monomeric sugar release following an enzymatic saccharification, must be compared. The experimental and data analysis protocols of the standard methods of analysis can be time-consuming, thereby limiting the number of samples that can be measured. High-throughput (HTP) methods alleviate the shortcomings of the standard methods, and permit the rapid screening of available samples to isolate those possessing the desired traits. This study illustrates the HTP sugar release and pyrolysis-molecular beam mass spectrometry pipelines employed at the National Renewable Energy Lab. These pipelines have enabled the efficient assessment of thousands of plants while decreasing experimental time and costs through reductions in labor and consumables. PMID:26437006

High-Throughput Screening of Recalcitrance Variations in Lignocellulosic Biomass: Total Lignin, Lignin Monomers, and Enzymatic Sugar Release

DOE Office of Scientific and Technical Information (OSTI.GOV)

Decker, Stephen R.; Sykes, Robert W.; Turner, Geoffrey B.

The conversion of lignocellulosic biomass to fuels, chemicals, and other commodities has been explored as one possible pathway toward reductions in the use of non-renewable energy sources. In order to identify which plants, out of a diverse pool, have the desired chemical traits for downstream applications, attributes, such as cellulose and lignin content, or monomeric sugar release following an enzymatic saccharification, must be compared. The experimental and data analysis protocols of the standard methods of analysis can be time-consuming, thereby limiting the number of samples that can be measured. High-throughput (HTP) methods alleviate the shortcomings of the standard methods, andmore » permit the rapid screening of available samples to isolate those possessing the desired traits. This study illustrates the HTP sugar release and pyrolysis-molecular beam mass spectrometry pipelines employed at the National Renewable Energy Lab. These pipelines have enabled the efficient assessment of thousands of plants while decreasing experimental time and costs through reductions in labor and consumables.« less

Production of d-lactic acid from hardwood pulp by mechanical milling followed by simultaneous saccharification and fermentation using metabolically engineered Lactobacillus plantarum.

PubMed

Hama, Shinji; Mizuno, Shino; Kihara, Maki; Tanaka, Tsutomu; Ogino, Chiaki; Noda, Hideo; Kondo, Akihiko

2015-01-01

This study focused on the process development for the d-lactic acid production from cellulosic feedstocks using the Lactobacillus plantarum mutant, genetically modified to produce optically pure d-lactic acid from both glucose and xylose. The simultaneous saccharification and fermentation (SSF) using delignified hardwood pulp (5-15% loads) resulted in the lactic acid titers of 55.2-84.6g/L after 72h and increased productivities of 1.77-2.61g/L/h. To facilitate the enzymatic saccharification of high-load pulp at a fermentation temperature, short-term (⩽10min) pulverization of pulp was conducted, leading to a significantly improved saccharification with the suppressed formation of formic acid by-product. The short-term milling followed by SSF resulted in a lactic acid titer of 102.3g/L, an optical purity of 99.2%, and a yield of 0.879g/g-sugars without fed-batch process control. Therefore, the process presented here shows promise for the production of high-titer d-lactic acid using the L. plantarum mutant. Copyright © 2015 Elsevier Ltd. All rights reserved.

Cost-effectiveness analysis of colorectal cancer screening methods in Iran.

PubMed

Allameh, Zahra; Davari, Majid; Emami, Mohammad Hasan

2011-03-01

Screening can prevent colorectal cancer from becoming advanced by early detection of precancerous lesions. Cost-effectiveness analysis of colorectal cancer screening methods is highly necessary due to increased prevalence, decreased age at onset and the limited budget in Iran. Methods of screening currently available in Iran were selected. A systematic search revealed the sensitivity and specificity of each method. For this study, a model for a 20 year screening period of a population of 100,000 apparently healthy persons of ages 45-65 years in Isfahan Province was used. The cost-effectiveness of each method and the ratio of cost-effectiveness were calculated based on this model. The most and the least effective methods were CT colonography and fecal occult blood test, respectively. The highest and lowest expenditures in the governmental sector were related to fecal occult blood test and flexible sigmoidoscopy and in the private sector, to CT colonography and fecal occult blood test, respectively. The cost per cancer detected in 20 years of screening in the governmental sector was 0.28, 0.22 and 0.42 billion Rials, respectively for screening by colonoscopy, flexible sigmoidoscopy and fecal occult blood test. In the private sector, these were 1.54 (colonoscopy), 1.68 (flexible sigmoidoscopy), and 1.60 (fecal occult blood test) billion and 2.58 billion Rials for CT colonography, respectively. Although CT colonography is the most effective method, it needs a budget of 2.58 billion Rials for each screened patient. If costs in the governmental sector are considered, flexible sigmoidoscopy would be the most cost-effective method for screening the 45 - 65-year-old population in Iran.

Simultaneous saccharification and ethanol fermentation of oxalic acid pretreated corncob assessed with response surface methodology

Treesearch

Jae-Won Lee; Rita C.L.B. Rodrigues; Thomas W. Jeffries

2009-01-01

Response surface methodology was used to evaluate optimal time, temperature and oxalic acid concentration for simultaneous saccharification and fermentation (SSF) of corncob particles by Pichia stipitis CBS 6054. Fifteen different conditions for pretreatment were examined in a 23 full factorial design with six axial points. Temperatures ranged from 132 to 180º...

A holistic high-throughput screening framework for biofuel feedstock assessment that characterises variations in soluble sugars and cell wall composition in Sorghum bicolor

PubMed Central

2013-01-01

Background A major hindrance to the development of high yielding biofuel feedstocks is the ability to rapidly assess large populations for fermentable sugar yields. Whilst recent advances have outlined methods for the rapid assessment of biomass saccharification efficiency, none take into account the total biomass, or the soluble sugar fraction of the plant. Here we present a holistic high-throughput methodology for assessing sweet Sorghum bicolor feedstocks at 10 days post-anthesis for total fermentable sugar yields including stalk biomass, soluble sugar concentrations, and cell wall saccharification efficiency. Results A mathematical method for assessing whole S. bicolor stalks using the fourth internode from the base of the plant proved to be an effective high-throughput strategy for assessing stalk biomass, soluble sugar concentrations, and cell wall composition and allowed calculation of total stalk fermentable sugars. A high-throughput method for measuring soluble sucrose, glucose, and fructose using partial least squares (PLS) modelling of juice Fourier transform infrared (FTIR) spectra was developed. The PLS prediction was shown to be highly accurate with each sugar attaining a coefficient of determination (R 2 ) of 0.99 with a root mean squared error of prediction (RMSEP) of 11.93, 5.52, and 3.23 mM for sucrose, glucose, and fructose, respectively, which constitutes an error of <4% in each case. The sugar PLS model correlated well with gas chromatography–mass spectrometry (GC-MS) and brix measures. Similarly, a high-throughput method for predicting enzymatic cell wall digestibility using PLS modelling of FTIR spectra obtained from S. bicolor bagasse was developed. The PLS prediction was shown to be accurate with an R 2 of 0.94 and RMSEP of 0.64 μg.mgDW-1.h-1. Conclusions This methodology has been demonstrated as an efficient and effective way to screen large biofuel feedstock populations for biomass, soluble sugar concentrations, and cell wall

Correlating physical changes and enhanced enzymatic saccharification of pine flour pretreated by Ν-Methylmorpholine-Ν-oxide

Treesearch

Ye Liu; Qixin Zhong; Siqun Wang; Zhiyong Cai

2011-01-01

Pretreatment of lignocellulosic biomass by Ν-methylmorpholine-Ν-oxide (NMMO), a solvent used in the textile industry to dissolve cellulose for production of regenerated cellulose fibers, was observed to enhance significantly enzymatic saccharification and fermentation. The enhancement was speculated to have been caused by reduced cellulose crystallinity...

DHAD variants and methods of screening

DOEpatents

Kelly, Kristen J.; Ye, Rick W.

2017-02-28

Methods of screening for dihydroxy-acid dehydratase (DHAD) variants that display increased DHAD activity are disclosed, along with DHAD variants identified by these methods. Such enzymes can result in increased production of compounds from DHAD requiring biosynthetic pathways. Also disclosed are isolated nucleic acids encoding the DHAD variants, recombinant host cells comprising the isolated nucleic acid molecules, and methods of producing butanol.

Advancement of Analysis Method for Electromagnetic Screening Effect of Mountain Tunnel

NASA Astrophysics Data System (ADS)

Okutani, Tamio; Nakamura, Nobuyuki; Terada, Natsuki; Fukuda, Mitsuyoshi; Tate, Yutaka; Inada, Satoshi; Itoh, Hidenori; Wakao, Shinji

In this paper we report advancement of an analysis method for electromagnetic screening effect of mountain tunnel with a multiple conductor circuit model. On A.C. electrified railways it is a great issue to manage the influence of electromagnetic induction caused by feeding circuits. Tunnels are said to have a screening effect to reduce the electromagnetic induction because a large amount of steel is used in the tunnels. But recently the screening effect is less expected because New Austrian Tunneling Method (NATM), in which the amount of steel used is less than in conventional methods, is adopted as the standard tunneling method for constructing mountain tunnels. So we measured and analyzed the actual screening effect of mountain tunnels constructed with NATM. In the process of the analysis we have advanced a method to analyze the screening effect more precisely. In this method we can adequately model tunnel structure as a part of multiple conductor circuit.

Rapid saccharification for production of cellulosic biofuels.

PubMed

Lee, Dae-Seok; Wi, Seung Gon; Lee, Soo Jung; Lee, Yoon-Gyo; Kim, Yeong-Suk; Bae, Hyeun-Jong

2014-04-01

The economical production of biofuels is hindered by the recalcitrance of lignocellulose to processing, causing high consumption of processing enzymes and impeding hydrolysis of pretreated lignocellulosic biomass. We determined the major rate-limiting factor in the hydrolysis of popping pre-treated rice straw (PPRS) by examining cellulase adsorption to lignin and cellulose, amorphogenesis of PPRS, and re-hydrolysis. Based on the results, equivalence between enzyme loading and the open structural area of cellulose was required to significantly increase productive adsorption of cellulase and to accelerate enzymatic saccharification of PPRS. Amorphogenesis of PPRS by phosphoric acid treatment to expand open structural area of the cellulose fibers resulted in twofold higher cellulase adsorption and increased the yield of the first re-hydrolysis step from 13% to 46%. The total yield from PPRS was increased to 84% after 3h. These results provide evidence that cellulose structure is one of major effects on the enzymatic hydrolysis. Copyright © 2014 Elsevier Ltd. All rights reserved.

Steam explosion treatment for ethanol production from branches pruned from pear trees by simultaneous saccharification and fermentation.

PubMed

Sasaki, Chizuru; Okumura, Ryosuke; Asada, Chikako; Nakamura, Yoshitoshi

2014-01-01

This study investigated the production of ethanol from unutilized branches pruned from pear trees by steam explosion pretreatment. Steam pressures of 25, 35, and 45 atm were applied for 5 min, followed by enzymatic saccharification of the extracted residues with cellulase (Cellic CTec2). High glucose recoveries, of 93.3, 99.7, and 87.1%, of the total sugar derived from the cellulose were obtained from water- and methanol-extracted residues after steam explosion at 25, 35, and 45 tm, respectively. These values corresponded to 34.9, 34.3, and 27.1 g of glucose per 100 g of dry steam-exploded branches. Simultaneous saccharification and fermentation experiments were done on water-extracted residues and water- and methanol-extracted residues by Kluyveromyces marxianus NBRC 1777. An overall highest theoretical ethanol yield of 76% of the total sugar derived from cellulose was achieved when 100 g/L of water- and methanol-washed residues from 35 atm-exploded pear branches was used as substrate.

Equity and practice issues in colorectal cancer screening: Mixed-methods study.

PubMed

Buchman, Sandy; Rozmovits, Linda; Glazier, Richard H

2016-04-01

To investigate overall colorectal cancer (CRC) screening rates, patterns in the use of types of CRC screening, and sociodemographic characteristics associated with CRC screening; and to gain insight into physicians' perceptions about and use of fecal occult blood testing [FOBT] and colonoscopy for patients at average risk of CRC. Mixed-methods study using cross-sectional administrative data on patient sociodemographic characteristics and semistructured telephone interviews with physicians. Toronto, Ont. Patients aged 50 to 74 years and physicians in family health teams in the Toronto Central Local Health Integration Network. Rates of CRC screening by type; sociodemographic characteristics associated with CRC screening; thematic analysis using constant comparative method for semistructured interviews. Ontario administrative data on CRC screening showed lower overall screening rates among those who were younger, male patients, those who had lower income, and recent immigrants. Colonoscopy rates were especially low among those with lower income and those who were recent immigrants. Semistructured interviews revealed that physician opinions about CRC screening for average-risk patients were divided: one group of physicians accepted the evidence and recommendations for FOBT and the other group of physicians strongly supported colonoscopy for these patients, believing that the FOBT was an inferior screening method. Physicians identified specialist recommendations and patient expectations as factors that influenced their decisions regarding CRC screening type. There was considerable variation in CRC screening by sociodemographic characteristics. A key theme that emerged from the interviews was that physicians were divided in their preference for FOBT or colonoscopy; factors that influenced physician preference included the health care system, recommendations by other specialists, and patient characteristics. Providing an informed choice of screening method to patients

Incorporation of flavonoid derivatives or pentagalloyl glucose into lignin enhances cell wall saccharification following mild alkaline or acidic pretreatments

USDA-ARS?s Scientific Manuscript database

Partial substitution of normal monolignols with phenolic precursors from other metabolic pathways may improve the susceptibility of lignified biomass to chemical pretreatment and enzymatic saccharification for biofuel production. Flavonoids and gallate esters readily undergo oxidative coupling react...

On energy consumption for size-reduction and yields from subsequent enzymatic saccharification of pretreated lodgepole pine

Treesearch

W. Zhu; Junyong Zhu; Roland Gleisner; X.J. Pan

2010-01-01

This study investigated the effects of chemical pretreatment and disk-milling conditions on energy consumption for size-reduction and the efficiency of enzymatic cellulose saccharification of a softwood. Lodgepole pine wood chips produced from thinnings of a 100-year-old unmanaged forest were pretreated by hot-water, dilute-acid, and two SPORL processes (Sulfite...

Organic acids associated with saccharification of cellulosic wastes during solid-state fermentation.

PubMed

El-Naggar, Noura El-Ahmady; El-Hersh, Mohammed Saad

2011-02-01

Saccharification of five cellulosic wastes, i.e. rice husks, wheat bran, corn cobs, wheat straw and rice straw by three cellulytic fungi, i.e. Aspergillus glaums MN1, Aspergillus oryzae MN2 and Penicillium purpurogenum MN3, during solid-state fermentation (SSF) was laboratory studied. Rice husks, wheat bran, and corn cobs were selected as inducers of glucose production in the tested fungi. An incubation interval of 10 days was optimal for glucose production. Maximal activities of the cellulases FP-ase, CMC-ase, and p-glucosidase were detected during SSF of rice husks by P. purpurogenum; however, a-amylase activity (7.2 U/g) was comparatively reduced. Meanwhile, the productivities of FP-ase, CMC-ase, and β-glucosidase were high during SSF of rice husks by A glaucus; however, they decreased during SSF of corn cobs by P. purpurogenum. Addition of rock phosphate (RP) (75 mg P(2)O(5)) decreased the pH of SSF media. (NH(4))(2)SO(4) was found to be less inducer of cellulytic enzymes, during SSF of rice husks by A. glaucus or A. oryzae; it also induced phytase production and solubilization of RP. The organic acids associated with saccharification of the wastes studied have also been investigated. The highest concentration of levulinic acid was detected (46.15 mg/g) during SSF of corn cobs by P. purpurogenum. Likewise, oxalic acid concentration was 43.20 mg/g during SSF of rice husks by P. purpurogenum.

Eliciting women's cervical screening preferences: a mixed methods systematic review protocol.

PubMed

Wood, Brianne; Van Katwyk, Susan Rogers; El-Khatib, Ziad; McFaul, Susan; Taljaard, Monica; Wright, Erica; Graham, Ian D; Little, Julian

2016-08-11

With the accumulation of evidence regarding potential harms of cancer screening in recent years, researchers, policy-makers, and the public are becoming more critical of population-based cancer screening. Consequently, a high-quality cancer screening program should consider individuals' values and preferences when determining recommendations. In cervical cancer screening, offering women autonomy is considered a "person-centered" approach to health care services; however, it may impact the effectiveness of the program should women choose to not participate. As part of a larger project to investigate women's cervical screening preferences and correlates of these preferences, this systematic review will capture quantitative and qualitative investigations of women's cervical screening preferences and the methods used to elicit them. This mixed methods synthesis will use a thematic analysis approach to synthesize qualitative, quantitative, and mixed methods evidence. This protocol describes the methods that will be used in this investigation. A search strategy has been developed with a health librarian and peer reviewed using PRESS. Based on this strategy, five databases and the gray literature will be searched for studies that meet the inclusion criteria. The quality of the included individual studies will be examined using the Mixed Methods Appraisal Tool. Three reviewers will extract data from the primary studies on the tools or instruments used to elicit women's preferences regarding cervical cancer screening, theoretical frameworks used, outcomes measured, the outstanding themes from quantitative and qualitative evidence, and the identified preferences for cervical cancer screening. We will describe the relationships between study results and the study population, "intervention" (e.g., tool or instrument), and context. We will follow the PRISMA reporting guideline. We will compare findings across studies and between study methods (e.g., qualitative versus

Saccharification of ozonated sugarcane bagasse using enzymes from Myceliophthora thermophila JCP 1-4 for sugars release and ethanol production.

PubMed

de Cassia Pereira, Josiani; Travaini, Rodolfo; Paganini Marques, Natalia; Bolado-Rodríguez, Silvia; Bocchini Martins, Daniela Alonso

2016-03-01

The saccharification of ozonated sugarcane bagasse (SCB) by enzymes from Myceliophthora thermophila JCP 1-4 was studied. Fungal enzymes provided slightly higher sugar release than commercial enzymes, working at 50°C. Sugar release increased with temperature increase. Kinetic studies showed remarkable glucose release (4.99 g/L, 3%w/w dry matter) at 60°C, 8 h of hydrolysis, using an enzyme load of 10 FPU (filter paper unit). FPase and β-glucosidase activities increased during saccharification (284% and 270%, respectively). No further significant improvement on glucose release was observed increasing the enzyme load above 7.5 FPU per g of cellulose. Higher dry matter contents increased sugars release, but not yields. The fermentation of hydrolysates by Saccharomyces cerevisiae provided glucose-to-ethanol conversions around to 63%. Copyright © 2015 Elsevier Ltd. All rights reserved.

Downregulation of RWA genes in hybrid aspen affects xylan acetylation and wood saccharification.

PubMed

Pawar, Prashant Mohan-Anupama; Ratke, Christine; Balasubramanian, Vimal K; Chong, Sun-Li; Gandla, Madhavi Latha; Adriasola, Mathilda; Sparrman, Tobias; Hedenström, Mattias; Szwaj, Klaudia; Derba-Maceluch, Marta; Gaertner, Cyril; Mouille, Gregory; Ezcurra, Ines; Tenkanen, Maija; Jönsson, Leif J; Mellerowicz, Ewa J

2017-06-01

High acetylation of angiosperm wood hinders its conversion to sugars by glycoside hydrolases, subsequent ethanol fermentation and (hence) its use for biofuel production. We studied the REDUCED WALL ACETYLATION (RWA) gene family of the hardwood model Populus to evaluate its potential for improving saccharification. The family has two clades, AB and CD, containing two genes each. All four genes are expressed in developing wood but only RWA-A and -B are activated by master switches of the secondary cell wall PtNST1 and PtMYB21. Histochemical analysis of promoter::GUS lines in hybrid aspen (Populus tremula × tremuloides) showed activation of RWA-A and -B promoters in the secondary wall formation zone, while RWA-C and -D promoter activity was diffuse. Ectopic downregulation of either clade reduced wood xylan and xyloglucan acetylation. Suppressing both clades simultaneously using the wood-specific promoter reduced wood acetylation by 25% and decreased acetylation at position 2 of Xylp in the dimethyl sulfoxide-extracted xylan. This did not affect plant growth but decreased xylose and increased glucose contents in the noncellulosic monosaccharide fraction, and increased glucose and xylose yields of wood enzymatic hydrolysis without pretreatment. Both RWA clades regulate wood xylan acetylation in aspen and are promising targets to improve wood saccharification. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Increased saccharification yields from aspen biomass upon treatment with enzymatically generated peracetic acid.

PubMed

Duncan, Shona; Jing, Qing; Katona, Adrian; Kazlauskas, Romas J; Schilling, Jonathan; Tschirner, Ulrike; Aldajani, Waleed Wafa

2010-03-01

The recalcitrance of lignocellulosic biomass to enzymatic release of sugars (saccharification) currently limits its use as feedstock for biofuels. Enzymatic hydrolysis of untreated aspen wood releases only 21.8% of the available sugars due primarily to the lignin barrier. Nature uses oxidative enzymes to selectively degrade lignin in lignocellulosic biomass, but thus far, natural enzymes have been too slow for industrial use. In this study, oxidative pretreatment with commercial peracetic acid (470 mM) removed 40% of the lignin (from 19.9 to 12.0 wt.% lignin) from aspen and enhanced the sugar yields in subsequent enzymatic hydrolysis to about 90%. Increasing the amount of lignin removed correlated with increasing yields of sugar release. Unfortunately, peracetic acid is expensive, and concentrated forms can be hazardous. To reduce costs and hazards associated with using commercial peracetic acid, we used a hydrolase to catalyze the perhydrolysis of ethyl acetate generating 60-70 mM peracetic acid in situ as a pretreatment to remove lignin from aspen wood. A single pretreatment was insufficient, but multiple cycles (up to eight) removed up to 61.7% of the lignin enabling release of >90% of the sugars during saccharification. This value corresponds to a predicted 581 g of fermentable sugars from 1 kg of aspen wood. Improvements in the enzyme stability are needed before the enzymatically generated peracetic acid is a commercially viable alternative.

Diagnostic methods for platelet bacteria screening: current status and developments.

PubMed

Störmer, Melanie; Vollmer, Tanja

2014-02-01

Bacterial contamination of blood components and the prevention of transfusion-associated bacterial infection still remains a major challenge in transfusion medicine. Over the past few decades, a significant reduction in the transmission of viral infections has been achieved due to the introduction of mandatory virus screening. Platelet concentrates (PCs) represent one of the highest risks for bacterial infection. This is due to the required storage conditions for PCs in gas-permeable containers at room temperature with constant agitation, which support bacterial proliferation from low contamination levels to high titers. In contrast to virus screening, since 1997 in Germany bacterial testing of PCs is only performed as a routine quality control or, since 2008, to prolong the shelf life to 5 days. In general, bacterial screening of PCs by cultivation methods is implemented by the various blood services. Although these culturing systems will remain the gold standard, the significance of rapid methods for screening for bacterial contamination has increased over the last few years. These new methods provide powerful tools for increasing the bacterial safety of blood components. This article summarizes the course of policies and provisions introduced to increase bacterial safety of blood components in Germany. Furthermore, we give an overview of the different diagnostic methods for bacterial screening of PCs and their current applicability in routine screening processes.

Diagnostic Methods for Platelet Bacteria Screening: Current Status and Developments

PubMed Central

Störmer, Melanie; Vollmer, Tanja

2014-01-01

Summary Bacterial contamination of blood components and the prevention of transfusion-associated bacterial infection still remains a major challenge in transfusion medicine. Over the past few decades, a significant reduction in the transmission of viral infections has been achieved due to the introduction of mandatory virus screening. Platelet concentrates (PCs) represent one of the highest risks for bacterial infection. This is due to the required storage conditions for PCs in gas-permeable containers at room temperature with constant agitation, which support bacterial proliferation from low contamination levels to high titers. In contrast to virus screening, since 1997 in Germany bacterial testing of PCs is only performed as a routine quality control or, since 2008, to prolong the shelf life to 5 days. In general, bacterial screening of PCs by cultivation methods is implemented by the various blood services. Although these culturing systems will remain the gold standard, the significance of rapid methods for screening for bacterial contamination has increased over the last few years. These new methods provide powerful tools for increasing the bacterial safety of blood components. This article summarizes the course of policies and provisions introduced to increase bacterial safety of blood components in Germany. Furthermore, we give an overview of the different diagnostic methods for bacterial screening of PCs and their current applicability in routine screening processes. PMID:24659944

Phenotypic selection of a wild Saccharomyces cerevisiae strain for simultaneous saccharification and co-fermentation of AFEX pretreated corn stover

Treesearch

Mingie Jin; Cory Sarks; Christa Gunawan; Benjamin D. Bice; Shane P. Simonett; Ragothaman Avanasi Narasimhan; Laura B. Willis; Bruce E. Dale; Venkatesh Balan; Trey K. Sato

2013-01-01

Simultaneous saccharification and co-fermentation (SSCF) process involves enzymatic hydrolysis of pretreated lignocellulosic biomass and fermentation of glucose and xylose in one bioreactor. The optimal temperatures for enzymatic hydrolysis are higher than the standard fermentation temperature of ethanologenic Saccharomyces cerevisiae. Moreover,...

77 FR 4544 - CPSC Symposium on Phthalates Screening and Testing Methods

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-30

... Screening and Testing Methods AGENCY: Consumer Product Safety Commission. ACTION: Notice. SUMMARY: The... symposium on phthalates screening and testing methods. The symposium will be held at the CPSC's National... submit comments, identified by Docket No. CPSC-2012-0008, by any of the following methods: Electronic...

Steam-exploded biomass saccharification is predominately affected by lignocellulose porosity and largely enhanced by Tween-80 in Miscanthus.

PubMed

Sun, Dan; Alam, Aftab; Tu, Yuanyuan; Zhou, Shiguang; Wang, Yanting; Xia, Tao; Huang, Jiangfeng; Li, Ying; Zahoor; Wei, Xiaoyang; Hao, Bo; Peng, Liangcai

2017-09-01

In this study, total ten Miscanthus accessions exhibited diverse cell wall compositions, leading to largely varied hexoses yields at 17%-40% (% cellulose) released from direct enzymatic hydrolysis of steam-exploded (SE) residues. Further supplied with 2% Tween-80 into the enzymatic digestion, the Mis7 accession showed the higher hexose yield by 14.8-fold than that of raw material, whereas the Mis10 had the highest hexoses yield at 77% among ten Miscanthus accessions. Significantly, this study identified four wall polymer features that negatively affect biomass saccharification as p<0.05 or 0.01 in the SE residues, including cellulose DP, Xyl and Ara of hemicellulose, and S-monomer of lignin. Based on Simons' stain, the SE porosity (defined by DY/DB) was examined to be the unique positive factor on biomass enzymatic digestion. Hence, this study provides the potential strategy to enhance biomass saccharification using optimal biomass process technology and related genetic breeding in Miscanthus and beyond. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparative evaluation of chemical and enzymatic saccharification of mixotrophically grown de-oiled microalgal biomass for reducing sugar production.

PubMed

Pancha, Imran; Chokshi, Kaumeel; Maurya, Rahulkumar; Bhattacharya, Sourish; Bachani, Pooja; Mishra, Sandhya

2016-03-01

For the commercialization of microalgal based biofuels, utilization of de-oiled carbohydrate rich biomass is important. In the present study, chemo-enzymatic hydrolysis of mixotrophically grown Scenedesmus sp. CCNM 1077 de-oiled biomass is evaluated. Among the chemical hydrolysis, use of 0.5M HCl for 45 min at 121°C resulted in highest saccharification yield of 37.87% w/w of de-oiled biomass. However, enzymatic hydrolysis using Viscozyme L at loading rate of 20 FBGU/g of de-oiled biomass, pH 5.5 and temperature 45°C for 72 h resulted in saccharification yield of 43.44% w/w of de-oiled biomass. Further, 78% ethanol production efficiency was achieved with enzymatically hydrolyzed de-oiled biomass using yeast Saccharomyces cerevisiae ATCC 6793. These findings of the present study show application of mixotrophically grown de-oiled biomass of Scenedesmus sp. CCNM 1077 as promising feedstock for bioethanol production. Copyright © 2016 Elsevier Ltd. All rights reserved.

Optimization of the simultaneous saccharification and fermentation process using thermotolerant yeasts.

PubMed

Ballesteros, I; Oliva, J M; Ballesteros, M; Carrasco, J

1993-01-01

Different treatments to improve the thermotolerance of fermenting yeasts for simultaneous ethanol saccharification and fermentation process of cellulosic materials have been examined. Yeasts of the genera Saccharomyces and Kluyveromyces were tested for growth and fermentation at progressively higher temperatures in the range of 42-47 degrees C. The best results were obtained with K. marxianus LG, which was then submitted to different treatments in order to achieve thermotolerant clones. A total of 35 new clones were obtained that dramatically improved the SSF of 10% Solka-floc substrate at 45 degrees C when compared to the original strain, some with ethanol concentrations as high as 33 g/L.

Facilitating the enzymatic saccharification of pulped bamboo residues by degrading the remained xylan and lignin-carbohydrates complexes.

PubMed

Huang, Caoxing; He, Juan; Li, Xin; Min, Douyong; Yong, Qiang

2015-09-01

Kraft pulping was performed on bamboo residues and its impact on the chemical compositions and the enzymatic digestibility of the samples were investigated. To improve the digestibility of sample by degrading the xylan and lignin-carbohydrates complexes (LCCs), xylanase and α-L-arabinofuranosidase (AF) were supplemented with cellulase. The results showed more carbohydrates were remained in the samples pulped with low effective alkali (EA) charge, compared to conventional kraft pulping. When 120 IU/g xylanase and 15 IU/g AF were supplemented with 20 FPU/g cellulase, the xylan degradation yield of the sample pulped with 12% EA charge increased from 68.20% to 88.35%, resulting in an increased enzymatic saccharification efficiency from 58.98% to 83.23%. The amount of LCCs in this sample decreased from 8.63/100C9 to 2.99/100C9 after saccharification with these enzymes. The results indicated that degrading the remained xylan and LCCs in the pulp could improve its enzymatic digestibility. Copyright © 2015 Elsevier Ltd. All rights reserved.

Comparative study on the conventional and non thermal simultaneous saccharification and fermentation of Manihot glaziovii root starch

NASA Astrophysics Data System (ADS)

Hargono, Kumoro, Andri Cahyo; Jos, Bakti

2015-12-01

Inconventional ethanol production process, starch is converted into dextrins via liquefaction using α-amylase enzyme at high temperature (90-120°C). Then, dextrins are saccharified by glucoamylase to obtain to monomeric sugars (glucose). Recently, a granular starch hydrolyzing enzymes (GSHE), Stargen 002, was developed to convert starch into dextrins at low temperature (< 32°C) and hydrolyzes dextrins into glucose. The subject of this research was to compare ethanol production using a granular starch hydrolyzing enzymes and conventional enzymatic liquefaction and saccharification in cassava starch processing. Starch slurry concentrations were 20% w/v, and dosage of enzymes 0.50, 1.0 and 2%, respectively, were studied. After 48 hr process the final ethanol concentration for the respective enzyme concentration for conventional process were 34.90, 36.16 and 42.10 g/L, whereas for the non-thermal treatment, final ethanol concentration were 46.4, 57.62 and 59.65 g/L, respectively. By implementation of this non thermal process, the use of energy can be saved by carrying out saccharification step at lower temperature (30°C) could be realized.

Rapid automated method for screening of enteric pathogens from stool specimens.

PubMed Central

Villasante, P A; Agulla, A; Merino, F J; Pérez, T; Ladrón de Guevara, C; Velasco, A C

1987-01-01

A total of 800 colonies suggestive of Salmonella, Shigella, or Yersinia species isolated on stool differential agar media were inoculated onto both conventional biochemical test media (triple sugar iron agar, urea agar, and phenylalanine agar) and Entero Pathogen Screen cards of the AutoMicrobic system (Vitek Systems, Inc., Hazelwood, Mo.). Based on the conventional tests, the AutoMicrobic system method yielded the following results: 587 true-negatives, 185 true-positives, 2 false-negatives, and 26 false-positives (sensitivity, 99%; specificity, 96%). Both true-positive and true-negative results were achieved considerably earlier than false results (P less than 0.001). The Entero Pathogen Screen card method is a fast, easy, and sensitive method for screening for Salmonella, Shigella, or Yersinia species. The impossibility of screening for oxidase-positive pathogens is a minor disadvantage of this method. PMID:3553230

Diagnostic methods of TSH in thyroid screening tests.

PubMed

Matyjaszek-Matuszek, Beata; Pyzik, Aleksandra; Nowakowski, Andrzej; Jarosz, Mirosław J

2013-01-01

Reliable and quick thyreologic diagnostics, as well as verification of the effectiveness of the therapy undertaken, is of great importance for the state of health of society. The measurement of plasma TSH is the commonly accepted and most sensitive screening test for primary thyroid disorders, which are the most frequent diseases related to the endocrine glands. At present, the available methods for the determination of TSH are characterized by high sensitivity ≤0.01 µIU/ml and lack of cross-reactivity. However, many drugs and substances, as well as pathological conditions, may affect the TSH level. evaluation of contemporary laboratory methods for the determination of TSH and the principles of interpretation of screening tests. In many countries, the TSH test is the only test performed in the diagnostics of thyroid function; nevertheless, it seems that for genuine and objective assessment of thyroid status the TSH level, together with FT4 level, should be absolutely determined, which allows the differentiation and assessment of the intensity of thyroid function disorders and foresee its consequences. The interpretation of TSH results in screening tests is different in such population groups as: children aged under 14, pregnant women, the elderly, and patients with non-thyroidal illnesses. From among currently used laboratory methods for determination of TSH levels, third generation non-isotopic methods are most frequently recommended, especially the method of immunochemiluminescence.

Screening-Level Ecological Risk Assessment Methods, Revision 3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mirenda, Richard J.

2012-08-16

This document provides guidance for screening-level assessments of potential adverse impacts to ecological resources from release of environmental contaminants at the Los Alamos National Laboratory (LANL or the Laboratory). The methods presented are based on two objectives, namely: to provide a basis for reaching consensus with regulators, managers, and other interested parties on how to conduct screening-level ecological risk investigations at the Laboratory; and to provide guidance for ecological risk assessors under the Environmental Programs (EP) Directorate. This guidance promotes consistency, rigor, and defensibility in ecological screening investigations and in reporting those investigation results. The purpose of the screening assessmentmore » is to provide information to the risk managers so informed riskmanagement decisions can be made. This document provides examples of recommendations and possible risk-management strategies.« less

Enzymatic saccharification of seaweeds into fermentable sugars by xylanase from marine Bacillus sp. strain BT21.

PubMed

Parab, Pankaj; Khandeparker, Rakhee; Amberkar, Ujwala; Khodse, Vishwas

2017-10-01

Enzymatic hydrolysis of seaweed biomass was studied using xylanase produced from marine bacteria Bacillus sp. strain BT21 through solid-state fermentation of wheat bran. Three types of seaweeds, Ahnfeltia plicata , Padina tetrastromatica and Ulva lactuca , were selected as representatives of red, brown, and green seaweeds, respectively. Seaweed biomass was pretreated with hot water. The efficiency of pretreated biomass to release reducing sugar by the action of xylanase as well as the type of monosaccharide released during enzyme saccharification of seaweed biomass was studied. It was seen that pretreated biomass of seaweed A. plicata, U. lactuca , and P. tetrastroma , at 121 °C for 45 min, followed by incubation with 50 IU xylanase released reducing sugars of 233 ± 5.3, 100 ± 6.1 and 73.3 ± 4.1 µg/mg of seaweed biomass, respectively. Gas chromatography analysis illustrated the release of xylose, glucose, and mannose during the treatment process. Hot water pre-treatment process enhanced enzymatic conversion of biomass into sugars. This study revealed the important role of xylanase in saccharification of seaweed, a promising feedstock for third-generation bioethanol production.

pH-Induced Lignin Surface Modification to Reduce Nonspecific Cellulase Binding and Enhance Enzymatic Saccharification of Lignocelluloses

Treesearch

Hongming Lou; J.Y. Zhu; Tian Qing Lan; Huranran Lai; Xueqing Qiu

2013-01-01

We studied the mechanism of the significant enhancement in the enzymatic saccharification of lignocelluloses at an elevated pH of 5.5–6.0. Four lignin residues with different sulfonic acid contents were isolated from enzymatic hydrolysis of lodgepole pine pretreated by either dilute acid (DA) or sulfite pretreatment to overcome recalcitrance of lignocelluloses (SPORL...

Biomimetic cell wall model studies to identify new lignin bioengineering targets for improving biomass susceptibility to pretreatment and enzymatic saccharification

USDA-ARS?s Scientific Manuscript database

Increasingly, bioengineering of lignin to contain atypical building blocks from other metabolic pathways is being pursued to custom-design lignin that is easier to remove by chemical pretreatments and less inhibitory toward polysaccharide saccharification. Because plants produce such a diverse array...

Saccharification of bamboo carbohydrates for the production of ethanol

DOE Office of Scientific and Technical Information (OSTI.GOV)

De Menezes, T.J.B.; Azzini, A.; Dos Santos, C.L.M.

1983-04-01

Bamboo carbohydrates were hydrolyzed with commercial amylases and a mixture of fungal culture broths containing cellulolytic and hemicellulolytic enzymes. The effects of cooking temperature and the size of fiber particles were also investigated. It was found that the higher the cooking temperature, the higher the rate of sugar formation and the lower the viscosity of the slurry. Additions of cellulose and hemicellulose digesting enzymes increased the sugar yield and decreased the viscosity of both the cooked and noncooked slurries. A smaller size of particle appeared to favor the average saccharification rate. Although glucose, xylose, and cellobiose were present in themore » hydrolysates, only 50% of the total carbohydrate was digested, and 78.9% of this was converted to reducing sugars. The alcohol efficiency for the fermentation of cooked and noncooked mashes by Saccharomyces was about 85%.« less

Effect of steam explosion on waste copier paper alone and in a mixed lignocellulosic substrate on saccharification and fermentation

PubMed Central

Elliston, Adam; Wilson, David R.; Wellner, Nikolaus; Collins, Samuel R.A.; Roberts, Ian N.; Waldron, Keith W.

2015-01-01

This study evaluated steam (SE) explosion on the saccharification and simultaneous saccharification and fermentation (SSF) of waste copier paper. SE resulted in a colouration, a reduction in fibre thickness and increased water absorption. Changes in chemical composition were evident at severities greater than 4.24 resulting in a loss of xylose and the production of breakdown products known to inhibit fermentation (particularly formic acid and acetic acid). SE did not improve final yields of glucose or ethanol, and at severities 4.53 and 4.83 reduced yields probably due to the effect of breakdown products and fermentation inhibitors. However, at moderate severities of 3.6 and 3.9 there was an increase in initial rates of hydrolysis which may provide a basis for reducing processing times. Co-steam explosion of waste copier paper and wheat straw attenuated the production of breakdown products, and may also provide a basis for improving SSF of lignocellulose. PMID:25846183

Enzymatic Hydrolysis and Simultaneous Saccharification and Fermentation of Soybean Processing Intermediates for the Production of Ethanol and Concentration of Protein and Lipids

PubMed Central

Long, Craig C.; Gibbons, William

2012-01-01

Carbohydrates in soybeans are generally undesirable due to their low digestibility and because they “dilute” more valuable components (proteins, lipids). To remove these carbohydrates and raise the titer of more valuable components, ethanol production was investigated. Commercial enzymes (Novozyme cellulase, β-glucosidase, and pectinase) were added to ground soybeans (SB), soybean meal (SBM), soybean hulls (SH), and soybean white flakes (WF) at a 10% solids loading rate to quantify hydrolyzed glucan. Saccharification resulted in glucan reductions of 28%, 45%, 76%, and 80% (SBM, SB, SH, WF, resp.). Simultaneous saccharification and fermentation (SSF) trials were conducted at 5%, 10%, 15%, and 20% solids loading with Saccharomyces cerevisiae NRRL Y-2034 and Scheffersomyces stipitis NRRL Y-7124, with protein, fiber, and lipids analyzed at SSF 10% solids and saccharification trials. S. cerevisiae and S. stipitis produced ~3–12.5 g/L ethanol and ~2.5–8.6 g/L ethanol, respectively, on SB, SBM, and WF over all solid loading rates. SH resulted in higher ethanol titers for both S. cerevisiae (~9–23 g/L) and S. stipitis (~9.5–14.5 g/L). Protein concentrations decreased by 2.5–10% for the SB, SBM, and WF, but increased by 53%–55% in SH. Oil concentrations increased by ~50% for SB; by ~500%–1300% for the others. PMID:23762751

A virtual screening method for inhibitory peptides of Angiotensin I-converting enzyme.

PubMed

Wu, Hongxi; Liu, Yalan; Guo, Mingrong; Xie, Jingli; Jiang, XiaMin

2014-09-01

Natural small peptides from foods have been proven to be efficient inhibitors of Angiotensin I-converting enzyme (ACE) for the regulation of blood pressure. The traditional ACE inhibitory peptides screening method is both time consuming and money costing, to the contrary, virtual screening method by computation can break these limitations. We establish a virtual screening method to obtain ACE inhibitory peptides with the help of Libdock module of Discovery Studio 3.5 software. A significant relationship between Libdock score and experimental IC(50) was found, Libdock score = 10.063 log(1/IC(50)) + 68.08 (R(2) = 0.62). The credibility of the relationship was confirmed by testing the coincidence of the estimated log(1/IC(50)) and measured log(1/IC(50)) (IC(50) is 50% inhibitory concentration toward ACE, in μmol/L) of 5 synthetic ACE inhibitory peptides, which was virtual hydrolyzed and screened from a kind of seafood, Phascolosoma esculenta. Accordingly, Libdock method is a valid IC(50) estimation tool and virtual screening method for small ACE inhibitory peptides. © 2014 Institute of Food Technologists®

Optimization of Bioethanol Production Using Whole Plant of Water Hyacinth as Substrate in Simultaneous Saccharification and Fermentation Process

PubMed Central

Zhang, Qiuzhuo; Weng, Chen; Huang, Huiqin; Achal, Varenyam; Wang, Duanchao

2016-01-01

Water hyacinth was used as substrate for bioethanol production in the present study. Combination of acid pretreatment and enzymatic hydrolysis was the most effective process for sugar production that resulted in the production of 402.93 mg reducing sugar at optimal condition. A regression model was built to optimize the fermentation factors according to response surface method in saccharification and fermentation (SSF) process. The optimized condition for ethanol production by SSF process was fermented at 38.87°C in 81.87 h when inoculated with 6.11 ml yeast, where 1.291 g/L bioethanol was produced. Meanwhile, 1.289 g/L ethanol was produced during experimentation, which showed reliability of presented regression model in this research. The optimization method discussed in the present study leading to relatively high bioethanol production could provide a promising way for Alien Invasive Species with high cellulose content. PMID:26779125

Improved enzymatic saccharification of steam exploded cotton stalk using alkaline extraction and fermentation of cellulosic sugars into ethanol.

PubMed

Keshav, Praveen K; Naseeruddin, Shaik; Rao, L Venkateswar

2016-08-01

Cotton stalk, a widely available and cheap agricultural residue lacking economic alternatives, was subjected to steam explosion in the range 170-200°C for 5min. Steam explosion at 200°C and 5min led to significant hemicellulose solubilization (71.90±0.10%). Alkaline extraction of steam exploded cotton stalk (SECOH) using 3% NaOH at room temperature for 6h led to 85.07±1.43% lignin removal with complete hemicellulose solubilization. Besides, this combined pretreatment allowed a high recovery of the cellulosic fraction from the biomass. Enzymatic saccharification was studied between steam exploded cotton stalk (SECS) and SECOH using different cellulase loadings. SECOH gave a maximum of 785.30±8.28mg/g reducing sugars with saccharification efficiency of 82.13±0.72%. Subsequently, fermentation of SECOH hydrolysate containing sugars (68.20±1.16g/L) with Saccharomyces cerevisiae produced 23.17±0.84g/L ethanol with 0.44g/g yield. Copyright © 2016 Elsevier Ltd. All rights reserved.

Improvement of screening methods for silicon planar semiconductor devices

NASA Technical Reports Server (NTRS)

Berger, W. M.

1972-01-01

The results of the program for the development of a more sensitive method for selecting silicon planar semiconductor devices for long life applications are reported. The manufacturing technologies (MOS and Bipolar) are discussed along with the screening procedures developed as a result of the tests and evaluations, and the effectiveness of the MOS and Bilayer screening procedures are evaluated.

Delignification of sugarcane bagasse using glycerol-water mixtures to produce pulps for saccharification.

PubMed

Novo, Lísias Pereira; Gurgel, Leandro Vinícius Alves; Marabezi, Karen; Curvelo, Antonio Aprigio da Silva

2011-11-01

This paper describes the organosolv delignification of depithed bagasse using glycerol-water mixtures without a catalyst. The experiments were performed using two separate experimental designs. In the first experiment, two temperatures (150 and 190°C), two time periods (60 and 240 min) and two glycerol contents (20% and 80%, v/v) were used. In the second experiment, which was a central composite design, the glycerol content was maintained at 80%, and a range of temperatures (141.7-198.3°C) and time (23-277 min) was used. The best result, obtained with a glycerol content of 80%, a reaction time of 150 min and a temperature of 198.3°C, produced pulps with 54.4% pulp yield, 7.75% residual lignin, 81.4% delignification and 13.7% polyose content. The results showed that high contents of glycerol tend to produce pulps with higher delignification and higher polyoses content in relation to the pulps obtained from low glycerol content reactions. In addition, the proposed method shows potential as a pretreatment for cellulose saccharification. Copyright © 2011 Elsevier Ltd. All rights reserved.

Butanol production from lignocellulose by simultaneous fermentation, saccharification, and pervaporation or vacuum evaporation.

PubMed

Díaz, Víctor Hugo Grisales; Tost, Gerard Olivar

2016-10-01

Techno-economic study of acetone, butanol and ethanol (ABE) fermentation from lignocellulose was performed. Simultaneous saccharification, fermentation and vacuum evaporation (SFS-V) or pervaporation (SFS-P) were proposed. A kinetic model of metabolic pathways for ABE fermentation with the effect of phenolics and furans in the growth was proposed based on published laboratory results. The processes were optimized in Matlab®. The end ABE purification was carried out by heat-integrated distillation. The objective function of the minimization was the total annualized cost (TAC). Fuel consumption of SFS-P using poly[1-(trimethylsilyl)-1-propyne] membrane was between 13.8 and 19.6% lower than SFS-V. Recovery of furans and phenolics for the hybrid reactors was difficult for its high boiling point. TAC of SFS-P was increased 1.9 times with supplementation of phenolics and furans to 3g/l each one for its high toxicity. Therefore, an additional detoxification method or an efficient pretreatment process will be necessary. Copyright © 2016 Elsevier Ltd. All rights reserved.

Three screening methods for cognitive dysfunction using the Mini-Mental State Examination and Korean Dementia Screening Questionnaire.

PubMed

Choi, Seong Hye; Park, Moon Ho

2016-02-01

To screen for and determine cognitive dysfunction, cognitive tests and/or informant reports are commonly used. However, these cognitive tests and informant reports are not always available. The present study investigated three screening methods using the Mini-Mental State Examination (MMSE) as the cognitive test, and the Korean dementia screening questionnaire (KDSQ) as the informant report. Participants were recruited from the Korea Clinical Research Center for Dementia of South Korea, and included 2861 patients with Alzheimer's disease (dementia), 3519 patients with mild cognitive impairment and 1375 controls with no cognitive dysfunction. Three screening methods were tested: (i) MMSE alone (MMSE(cut-off) ); (ii) a conventional combination of MMSE and KDSQ (MMSE+KDSQ(cut-off) ); and (iii) a decision tree with MMSE and KDSQ (MMSE+KDSQ(decision tree) ). For discriminating any cognitive dysfunction from controls, MMSE+KDSQ(cut-off) had the highest area under the receiver operating characteristic curve (0.784). For discriminating dementia from controls, MMSE+KDSQ(cut-off) had the highest area under the receiver operating characteristic curve (0.899). For discriminating mild cognitive impairment from controls, MMSE(cut-off) had the highest area under the receiver operating characteristic curve (0.683). MMSE+KDSQ(decision tree) showed the highest sensitivity for all discriminations. For overall classification accuracy, MMSE+KDSQ(decision tree) had the highest value (70.0%). These three methods had different advantageous properties for screening and staging cognitive dysfunction. As there might be different availability across clinical settings, these three methods can be selected and used according to situational needs. © 2015 Japan Geriatrics Society.

Ethanol production from sunflower meal biomass by simultaneous saccharification and fermentation (SSF) with Kluyveromyces marxianus ATCC 36907.

PubMed

Camargo, Danielle; Gomes, Simone D; Sene, Luciane

2014-11-01

The lignocellulosic materials are considered promising renewable resources for ethanol production, but improvements in the processes should be studied to reduce operating costs. Thus, the appropriate enzyme loading for cellulose saccharification is critical for process economics. This study aimed at evaluating the concentration of cellulase and β-glucosidase in the production of bioethanol by simultaneous saccharification and fermentation (SSF) of sunflower meal biomass. The sunflower biomass was pretreated with 6% H2SO4 (w/v), at 121 °C, for 20 min, for hemicellulose removal and delignificated with 1% NaOH. SSF was performed with Kluyveromyces marxianus ATCC 36907, at 38 °C, 150 rpm, for 72 h, with different enzyme concentrations (Cellulase Complex NS22086-10, 15 and 20 FPU/gsubstrate and β-Glucosidase NS22118, with a cellulase to β-glucosidase ratio of 1.5:1; 2:1 and 3:1). The best condition for ethanol production was cellulase 20 FPU/gsubstrate and β-glucosidase 13.3 CBU/gsubstrate, resulting in 27.88 g/L ethanol, yield of 0.47 g/g and productivity of 0.38 g/L h. Under this condition the highest enzymatic conversion of cellulose to glucose was attained (87.06%).

Impact of Pretreatment Technologies on Saccharification and Isopentenol Fermentation of Mixed Lignocellulosic Feedstocks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shi, Jian; George, Kevin W.; Sun, Ning

2015-02-28

In order to enable the large-scale production of biofuels or chemicals from lignocellulosic biomass, a consistent and affordable year-round supply of lignocellulosic feedstocks is essential. Feedstock blending and/or densification offers one promising solution to overcome current challenges on biomass supply, i.e., low energy and bulk densities and significant compositional variations. Therefore, it is imperative to develop conversion technologies that can process mixed pelleted biomass feedstocks with minimal negative impact in terms of overall performance of the relevant biorefinery unit operations: pretreatment, fermentable sugar production, and fuel titers. We processed the mixture of four feedstocks—corn stover, switchgrass, lodgepole pine, and eucalyptusmore » (1:1:1:1 on dry weight basis)—in flour and pellet form using ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate, dilute sulfuric acid (DA), and soaking in aqueous ammonia (SAA) pretreatments. Commercial enzyme mixtures, including cellulases and hemicellulases, were then applied to these pretreated feedstocks at low to moderate enzyme loadings to determine hydrolysis efficiency. Results show significant variations on the chemical composition, crystallinity, and enzymatic digestibility of the pretreated feedstocks across the different pretreatment technologies studied. The advanced biofuel isopentenol was produced during simultaneous saccharification and fermentation (SSF) of pretreated feedstocks using an engineered Escherichia coli strain. Results show that IL pretreatment liberates the most sugar during enzymatic saccharification, and in turn led to the highest isopentenol titer as compared to DA and SAA pretreatments. This study provides insights on developing biorefinery technologies that produce advanced biofuels based on mixed feedstock streams.« less

Experimental cocrystal screening and solution based scale-up cocrystallization methods.

PubMed

Malamatari, Maria; Ross, Steven A; Douroumis, Dennis; Velaga, Sitaram P

2017-08-01

Cocrystals are crystalline single phase materials composed of two or more different molecular and/or ionic compounds generally in a stoichiometric ratio which are neither solvates nor simple salts. If one of the components is an active pharmaceutical ingredient (API), the term pharmaceutical cocrystal is often used. There is a growing interest among drug development scientists in exploring cocrystals, as means to address physicochemical, biopharmaceutical and mechanical properties and expand solid form diversity of the API. Conventionally, coformers are selected based on crystal engineering principles, and the equimolar mixtures of API and coformers are subjected to solution-based crystallization that are commonly employed in polymorph and salt screening. However, the availability of new knowledge on cocrystal phase behaviour in solid state and solutions has spurred the development and implementation of more rational experimental cocrystal screening as well as scale-up methods. This review aims to provide overview of commonly employed solid form screening techniques in drug development with an emphasis on cocrystal screening methodologies. The latest developments in understanding and the use of cocrystal phase diagrams in both screening and solution based scale-up methods are also presented. Final section is devoted to reviewing the state of the art research covering solution based scale-up cocrystallization process for different cocrystals besides more recent continuous crystallization methods. Copyright © 2017 Elsevier B.V. All rights reserved.

Terbium-sensitized luminescence screening method for fluoroquinolones in beef serum

USDA-ARS?s Scientific Manuscript database

Enrofloxacin is one of only two fluoroquinolone antibiotics approved for use in cattle in the U.S. Microbial screening methods commonly used for monitoring veterinary drug residues are not sensitive or selective for fluoroquinolones. In this work, a luminescence-based screening assay was developed...

Simultaneous or separated; comparison approach for saccharification and fermentation process in producing bio-ethanol from EFB

NASA Astrophysics Data System (ADS)

Bardant, Teuku Beuna; Dahnum, Deliana; Amaliyah, Nur

2017-11-01

Simultaneous Saccharification Fermentation (SSF) of palm oil (Elaeis guineensis) empty fruit bunch (EFB) pulp were investigated as a part of ethanol production process. SSF was investigated by observing the effect of substrate loading variation in range 10-20%w, cellulase loading 5-30 FPU/gr substrate and yeast addition 1-2%v to the ethanol yield. Mathematical model for describing the effects of these three variables to the ethanol yield were developed using Response Surface Methodology-Cheminformatics (RSM-CI). The model gave acceptable accuracy in predicting ethanol yield for Simultaneous Saccharification and Fermentation (SSF) with coefficient of determination (R2) 0.8899. Model validation based on data from previous study gave (R2) 0.7942 which was acceptable for using this model for trend prediction analysis. Trend prediction analysis based on model prediction yield showed that SSF gave trend for higher yield when the process was operated in high enzyme concentration and low substrate concentration. On the other hand, even SHF model showed better yield will be obtained if operated in lower substrate concentration, it still possible to operate in higher substrate concentration with slightly lower yield. Opportunity provided by SHF to operate in high loading substrate make it preferable option for application in commercial scale.

Evaluation of nanoparticle-immobilized cellulase for improved ethanol yield in simultaneous saccharification and fermentation reactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lupoi, Jason; Smith, Emily

2011-12-01

Ethanol yields were 2.1 (P = 0.06) to 2.3 (P = 0.01) times higher in simultaneous saccharification and fermentation (SSF) reactions of microcrystalline cellulose when cellulase was physisorbed on silica nanoparticles compared to enzyme in solution. In SSF reactions, cellulose is hydrolyzed to glucose by cellulase while yeast simultaneously ferments glucose to ethanol. The 35 C temperature and the presence of ethanol in SSF reactions are not optimal conditions for cellulase. Immobilization onto solid supports can stabilize the enzyme and promote activity at non-optimum reaction conditions. Mock SSF reactions that did not contain yeast were used to measure saccharification productsmore » and identify the mechanism for the improved ethanol yield using immobilized cellulase. Cellulase adsorbed to 40 nm silica nanoparticles produced 1.6 times (P = 0.01) more glucose than cellulase in solution in 96 h at pH 4.8 and 35 C. There was no significant accumulation (<250 {mu}g) of soluble cellooligomers in either the solution or immobilized enzyme reactions. This suggests that the mechanism for the immobilized enzyme's improved glucose yield compared to solution enzyme is the increased conversion of insoluble cellulose hydrolysis products to soluble cellooligomers at 35 C and in the presence of ethanol. The results show that silica-immobilized cellulase can be used to produce increased ethanol yields in the conversion of lignocellulosic materials by SSF.« less

A deep learning method for early screening of lung cancer

NASA Astrophysics Data System (ADS)

Zhang, Kunpeng; Jiang, Huiqin; Ma, Ling; Gao, Jianbo; Yang, Xiaopeng

2018-04-01

Lung cancer is the leading cause of cancer-related deaths among men. In this paper, we propose a pulmonary nodule detection method for early screening of lung cancer based on the improved AlexNet model. In order to maintain the same image quality as the existing B/S architecture PACS system, we convert the original CT image into JPEG format image by analyzing the DICOM file firstly. Secondly, in view of the large size and complex background of CT chest images, we design the convolution neural network on basis of AlexNet model and sparse convolution structure. At last we train our models on the software named DIGITS which is provided by NVIDIA. The main contribution of this paper is to apply the convolutional neural network for the early screening of lung cancer and improve the screening accuracy by combining the AlexNet model with the sparse convolution structure. We make a series of experiments on the chest CT images using the proposed method, of which the sensitivity and specificity indicates that the method presented in this paper can effectively improve the accuracy of early screening of lung cancer and it has certain clinical significance at the same time.

Method of saccharifying cellulose

DOEpatents

Johnson, Eric A.; Demain, Arnold L.; Madia, Ashwin

1985-09-10

A method of saccharifying cellulose by incubation with the cellulase of Clostridium thermocellum in a broth containing an efficacious amount of a reducing agent. Other incubation parameters which may be advantageously controlled to stimulate saccharification include the concentration of alkaline earth salts, pH, temperature, and duration. By the method of the invention, even native crystalline cellulose such as that found in cotton may be completely saccharified.

Time-resolved luminescence screening method for enrofloxacin in beef serum

USDA-ARS?s Scientific Manuscript database

Enrofloxacin is one of only two fluoroquinolone antibiotics approved for use in cattle in the U.S. Microbial screening methods currently used in the U.S. for monitoring veterinary drug residues are not sensitive or selective for fluoroquinolones. In this work, a luminescence-based screening assay ...

Comparison of bio-hydrogen production yield capacity between asynchronous and simultaneous saccharification and fermentation processes from agricultural residue by mixed anaerobic cultures.

PubMed

Li, Yameng; Zhang, Zhiping; Zhu, Shengnan; Zhang, Huan; Zhang, Yang; Zhang, Tian; Zhang, Quanguo

2018-01-01

Taken common agricultural residues as substrate, dark fermentation bio-hydrogen yield capacity from asynchronous saccharification and fermentation (ASF) and simultaneous saccharification and fermentation (SSF) was investigated. The highest hydrogen yield of 472.75mL was achieved with corncob using ASF. Hydrogen yield from corn straw, rice straw, corncob and sorghum stalk by SSF were 20.54%,10.31%,13.99% and 5.92% higher than ASF, respectively. The experimental data fitted well to the modified Gompertz model. SSF offered a distinct advantage over ASF with respect to reducing overall process time (60h of SSF, 108h of ASF). Meanwhile, SSF performed better than SSF with respect to shortening the lag-stage. The major metabolites of anaerobic fermentation hydrogen production by ASF and SSF were butyric acid and acetic acid. Copyright © 2017 Elsevier Ltd. All rights reserved.

Development and evaluation of nursing user interface screens using multiple methods.

PubMed

Hyun, Sookyung; Johnson, Stephen B; Stetson, Peter D; Bakken, Suzanne

2009-12-01

Building upon the foundation of the Structured Narrative Electronic Health Record (EHR) model, we applied theory-based (combined Technology Acceptance Model and Task-Technology Fit Model) and user-centered methods to explore nurses' perceptions of functional requirements for an electronic nursing documentation system, design user interface screens reflective of the nurses' perspectives, and assess nurses' perceptions of the usability of the prototype user interface screens. The methods resulted in user interface screens that were perceived to be easy to use, potentially useful, and well-matched to nursing documentation tasks associated with Nursing Admission Assessment, Blood Administration, and Nursing Discharge Summary. The methods applied in this research may serve as a guide for others wishing to implement user-centered processes to develop or extend EHR systems. In addition, some of the insights obtained in this study may be informative to the development of safe and efficient user interface screens for nursing document templates in EHRs.

A new method to address verification bias in studies of clinical screening tests: cervical cancer screening assays as an example.

PubMed

Xue, Xiaonan; Kim, Mimi Y; Castle, Philip E; Strickler, Howard D

2014-03-01

Studies to evaluate clinical screening tests often face the problem that the "gold standard" diagnostic approach is costly and/or invasive. It is therefore common to verify only a subset of negative screening tests using the gold standard method. However, undersampling the screen negatives can lead to substantial overestimation of the sensitivity and underestimation of the specificity of the diagnostic test. Our objective was to develop a simple and accurate statistical method to address this "verification bias." We developed a weighted generalized estimating equation approach to estimate, in a single model, the accuracy (eg, sensitivity/specificity) of multiple assays and simultaneously compare results between assays while addressing verification bias. This approach can be implemented using standard statistical software. Simulations were conducted to assess the proposed method. An example is provided using a cervical cancer screening trial that compared the accuracy of human papillomavirus and Pap tests, with histologic data as the gold standard. The proposed approach performed well in estimating and comparing the accuracy of multiple assays in the presence of verification bias. The proposed approach is an easy to apply and accurate method for addressing verification bias in studies of multiple screening methods. Copyright © 2014 Elsevier Inc. All rights reserved.

Process integration for simultaneous saccharification, fermentation, and recovery (SSFR): Production of butanol from corn stover using Clostridium beijerinckii P260

USDA-ARS?s Scientific Manuscript database

A simultaneous saccharification, fermentation, and recovery (SSFR) process was developed for production of acetone butanol ethanol (AB or ABE), of which butanol is the main product, from corn stover employing Clostridium beijerinckii P260. Of the 86 gL^-1^ corn stover, over 97% of the sugars were r...

Simultaneous saccharification and viscosity reduction of cassava pulp using a multi-component starch- and cell-wall degrading enzyme for bioethanol production.

PubMed

Poonsrisawat, Aphisit; Paemanee, Atchara; Wanlapatit, Sittichoke; Piyachomkwan, Kuakoon; Eurwilaichitr, Lily; Champreda, Verawat

2017-10-01

In this study, an efficient ethanol production process using simultaneous saccharification and viscosity reduction of raw cassava pulp with no prior high temperature pre-gelatinization/liquefaction step was developed using a crude starch- and cell wall-degrading enzyme preparation from Aspergillus aculeatus BCC17849. Proteomic analysis revealed that the enzyme comprised a complex mixture of endo- and exo-acting amylases, cellulases, xylanases, and pectina ses belonging to various glycosyl hydrolase families. Enzymatic hydrolysis efficiency was dependent on the initial solid loading in the reaction. Reduction in mixture viscosity was observed with a rapid decrease in complex viscosity from 3785 to 0.45 Pa s with the enzyme dosage of 2.19 mg/g on a dried weight basis within the first 2 h, which resulted from partial destruction of the plant cell wall fiber and degradation of the released starch granules by the enzymes as shown by scanning electron microscopy. Saccharification of cassava pulp at an initial solid of 16% (w/v) in a bench-scale bioreactor resulted in 736.4 mg glucose/g, which is equivalent to 82.92% glucose yield based on the total starch and glucan in the substrate, after 96 h at 40 °C. Simultaneous saccharification and fermentation of cassava pulp by Saccharomyces cerevisiae with the uncooked enzymatic process led to a final ethanol concentration of 6.98% w/v, equivalent to 96.7% theoretical yield based on the total starch and cellulose content. The results demonstrated potential of the enzyme for low-energy processing of cassava pulp in biofuel industry.

Reverse screening methods to search for the protein targets of chemopreventive compounds

NASA Astrophysics Data System (ADS)

Huang, Hongbin; Zhang, Guigui; Zhou, Yuquan; Lin, Chenru; Chen, Suling; Lin, Yutong; Mai, Shangkang; Huang, Zunnan

2018-05-01

This article is a systematic review of reverse screening methods used to search for the protein targets of chemopreventive compounds or drugs. Typical chemopreventive compounds include components of traditional Chinese medicine, natural compounds and Food and Drug Administration (FDA)-approved drugs. Such compounds are somewhat selective but are predisposed to bind multiple protein targets distributed throughout diverse signaling pathways in human cells. In contrast to conventional virtual screening, which identifies the ligands of a targeted protein from a compound database, reverse screening is used to identify the potential targets or unintended targets of a given compound from a large number of receptors by examining their known ligands or crystal structures. This method, also known as in silico or computational target fishing, is highly valuable for discovering the target receptors of query molecules from terrestrial or marine natural products, exploring the molecular mechanisms of chemopreventive compounds, finding alternative indications of existing drugs by drug repositioning, and detecting adverse drug reactions and drug toxicity. Reverse screening can be divided into three major groups: shape screening, pharmacophore screening and reverse docking. Several large software packages, such as Schrödinger and Discovery Studio; typical software/network services such as ChemMapper, PharmMapper, idTarget and INVDOCK; and practical databases of known target ligands and receptor crystal structures, such as ChEMBL, BindingDB and the Protein Data Bank (PDB), are available for use in these computational methods. Different programs, online services and databases have different applications and constraints. Here, we conducted a systematic analysis and multilevel classification of the computational programs, online services and compound libraries available for shape screening, pharmacophore screening and reverse docking to enable non-specialist users to quickly learn and

Reverse Screening Methods to Search for the Protein Targets of Chemopreventive Compounds.

PubMed

Huang, Hongbin; Zhang, Guigui; Zhou, Yuquan; Lin, Chenru; Chen, Suling; Lin, Yutong; Mai, Shangkang; Huang, Zunnan

2018-01-01

This article is a systematic review of reverse screening methods used to search for the protein targets of chemopreventive compounds or drugs. Typical chemopreventive compounds include components of traditional Chinese medicine, natural compounds and Food and Drug Administration (FDA)-approved drugs. Such compounds are somewhat selective but are predisposed to bind multiple protein targets distributed throughout diverse signaling pathways in human cells. In contrast to conventional virtual screening, which identifies the ligands of a targeted protein from a compound database, reverse screening is used to identify the potential targets or unintended targets of a given compound from a large number of receptors by examining their known ligands or crystal structures. This method, also known as in silico or computational target fishing, is highly valuable for discovering the target receptors of query molecules from terrestrial or marine natural products, exploring the molecular mechanisms of chemopreventive compounds, finding alternative indications of existing drugs by drug repositioning, and detecting adverse drug reactions and drug toxicity. Reverse screening can be divided into three major groups: shape screening, pharmacophore screening and reverse docking. Several large software packages, such as Schrödinger and Discovery Studio; typical software/network services such as ChemMapper, PharmMapper, idTarget, and INVDOCK; and practical databases of known target ligands and receptor crystal structures, such as ChEMBL, BindingDB, and the Protein Data Bank (PDB), are available for use in these computational methods. Different programs, online services and databases have different applications and constraints. Here, we conducted a systematic analysis and multilevel classification of the computational programs, online services and compound libraries available for shape screening, pharmacophore screening and reverse docking to enable non-specialist users to quickly learn

Reverse Screening Methods to Search for the Protein Targets of Chemopreventive Compounds

PubMed Central

Huang, Hongbin; Zhang, Guigui; Zhou, Yuquan; Lin, Chenru; Chen, Suling; Lin, Yutong; Mai, Shangkang; Huang, Zunnan

2018-01-01

This article is a systematic review of reverse screening methods used to search for the protein targets of chemopreventive compounds or drugs. Typical chemopreventive compounds include components of traditional Chinese medicine, natural compounds and Food and Drug Administration (FDA)-approved drugs. Such compounds are somewhat selective but are predisposed to bind multiple protein targets distributed throughout diverse signaling pathways in human cells. In contrast to conventional virtual screening, which identifies the ligands of a targeted protein from a compound database, reverse screening is used to identify the potential targets or unintended targets of a given compound from a large number of receptors by examining their known ligands or crystal structures. This method, also known as in silico or computational target fishing, is highly valuable for discovering the target receptors of query molecules from terrestrial or marine natural products, exploring the molecular mechanisms of chemopreventive compounds, finding alternative indications of existing drugs by drug repositioning, and detecting adverse drug reactions and drug toxicity. Reverse screening can be divided into three major groups: shape screening, pharmacophore screening and reverse docking. Several large software packages, such as Schrödinger and Discovery Studio; typical software/network services such as ChemMapper, PharmMapper, idTarget, and INVDOCK; and practical databases of known target ligands and receptor crystal structures, such as ChEMBL, BindingDB, and the Protein Data Bank (PDB), are available for use in these computational methods. Different programs, online services and databases have different applications and constraints. Here, we conducted a systematic analysis and multilevel classification of the computational programs, online services and compound libraries available for shape screening, pharmacophore screening and reverse docking to enable non-specialist users to quickly learn

The evolving role of new imaging methods in breast screening.

PubMed

Houssami, Nehmat; Ciatto, Stefano

2011-09-01

The potential to avert breast cancer deaths through screening means that efforts continue to identify methods which may enhance early detection. While the role of most new imaging technologies remains in adjunct screening or in the work-up of mammography-detected abnormalities, some of the new breast imaging tests (such as MRI) have roles in screening groups of women defined by increased cancer risk. This paper highlights the evidence and the current role of new breast imaging technologies in screening, focusing on those that have broader application in population screening, including digital mammography, breast ultrasound in women with dense breasts, and computer-aided detection. It highlights that evidence on new imaging in screening comes mostly from non-randomised studies that have quantified test detection capability as adjunct to mammography, or have compared measures of screening performance for new technologies with that of conventional mammography. Two RCTs have provided high-quality evidence on the equivalence of digital and conventional mammography and on outcomes of screen-reading complemented by CAD. Many of these imaging technologies enhance cancer detection but also increase recall and false positives in screening. Copyright © 2011 Elsevier Inc. All rights reserved.

Simultaneous saccharification and cofermentation of peracetic acid-pretreated biomass.

PubMed

Teixeira, L C; Linden, J C; Schroeder, H A

2000-01-01

Previous work in our laboratories has demonstrated the effectiveness of peracetic acid for improving enzymatic digestibility of lignocellulosic materials. The use of dilute alkali solutions as a pre-pretreatment prior to peracetic acid lignin oxidation increased carbohydrate hydrolysis yields in a synergistic as opposed to additive manner. Deacetylation of xylan is easily achieved using dilute alkali solutions under mild conditions. In this article, we evaluate the effectiveness of peracetic acid combined with an alkaline pre-pretreatment through simultaneous saccharification and cofermentation (SSCF) of pretreated hybrid poplar wood and sugar cane bagasse. Respective ethanol yields of 92.8 and 91.9% of theoretical are achieved using 6% NaOH/15% peracetic acid-pretreated substrates and recombinant Zymomonas mobilis CP4/pZB5. Reduction of acetyl groups of the lignocellulosic materials is demonstrated following alkaline pre-pretreatments. Such processing may be helpful in reducing peracetic acid requirements. The influence of deacetylation is more significant in combined pretreatments using lower peracetic acid loadings.

Enhanced bioprocessing of lignocellulose: Wood-rot fungal saccharification and fermentation of corn fiber to ethanol

NASA Astrophysics Data System (ADS)

Shrestha, Prachand

This research aims at developing a biorefinery platform to convert corn-ethanol coproduct, corn fiber, into fermentable sugars at a lower temperature with minimal use of chemicals. White-rot (Phanerochaete chrysosporium), brown-rot (Gloeophyllum trabeum) and soft-rot (Trichoderma reesei) fungi were used in this research to biologically break down cellulosic and hemicellulosic components of corn fiber into fermentable sugars. Laboratory-scale simultaneous saccharification and fermentation (SSF) process proceeded by in-situ cellulolytic enzyme induction enhanced overall enzymatic hydrolysis of hemi/cellulose from corn fiber into simple sugars (mono-, di-, tri-saccharides). The yeast fermentation of hydrolyzate yielded 7.1, 8.6 and 4.1 g ethanol per 100 g corn fiber when saccharified with the white-, brown-, and soft-rot fungi, respectively. The highest corn-to-ethanol yield (8.6 g ethanol/100 g corn fiber) was equivalent to 42 % of the theoretical ethanol yield from starch and cellulose in corn fiber. Cellulase, xylanase and amylase activities of these fungi were also investigated over a week long solid-substrate fermentation of corn fiber. G. trabeum had the highest activities for starch (160 mg glucose/mg protein.min) and on day three of solid-substrate fermentation. P. chrysosporium had the highest activity for xylan (119 mg xylose/mg protein.min) on day five and carboxymethyl cellulose (35 mg glucose/mg protein.min) on day three of solid-substrate fermentation. T. reesei showed the highest activity for Sigma cell 20 (54.8 mg glucose/mg protein.min) on day 5 of solid-substrate fermentation. The effect of different pretreatments on SSF of corn fiber by fungal processes was examined. Corn fiber was treated at 30 °C for 2 h with alkali [2% NaOH (w/w)], alkaline peroxide [2% NaOH (w/w) and 1% H2O 2 (w/w)], and by steaming at 100 °C for 2 h. Mild pretreatment resulted in improved ethanol yields for brown- and soft-rot SSF, while white-rot and Spezyme CP SSFs showed

A Screening Method for Assessing Cumulative Impacts

PubMed Central

Alexeeff, George V.; Faust, John B.; August, Laura Meehan; Milanes, Carmen; Randles, Karen; Zeise, Lauren; Denton, Joan

2012-01-01

The California Environmental Protection Agency (Cal/EPA) Environmental Justice Action Plan calls for guidelines for evaluating “cumulative impacts.” As a first step toward such guidelines, a screening methodology for assessing cumulative impacts in communities was developed. The method, presented here, is based on the working definition of cumulative impacts adopted by Cal/EPA [1]: “Cumulative impacts means exposures, public health or environmental effects from the combined emissions and discharges in a geographic area, including environmental pollution from all sources, whether single or multi-media, routinely, accidentally, or otherwise released. Impacts will take into account sensitive populations and socio-economic factors, where applicable and to the extent data are available.” The screening methodology is built on this definition as well as current scientific understanding of environmental pollution and its adverse impacts on health, including the influence of both intrinsic, biological factors and non-intrinsic socioeconomic factors in mediating the effects of pollutant exposures. It addresses disparities in the distribution of pollution and health outcomes. The methodology provides a science-based tool to screen places for relative cumulative impacts, incorporating both the pollution burden on a community- including exposures to pollutants, their public health and environmental effects- and community characteristics, specifically sensitivity and socioeconomic factors. The screening methodology provides relative rankings to distinguish more highly impacted communities from less impacted ones. It may also help identify which factors are the greatest contributors to a community’s cumulative impact. It is not designed to provide quantitative estimates of community-level health impacts. A pilot screening analysis is presented here to illustrate the application of this methodology. Once guidelines are adopted, the methodology can serve as a screening

A screening method for biotinidase deficiency in newborns.

PubMed

Heard, G S; Secor McVoy, J R; Wolf, B

1984-01-01

We describe a method for neonatal screening for biotinidase (EC 3.5.1.12) deficiency. Biotinidase activity is assessed colorimetrically from dried samples of whole blood spotted on the same filter papers as used in the neonatal screening for phenylketonuria. After the reaction, samples from normal infants are characteristically purple, whereas those from affected individuals are straw-colored. To confirm the deficiency, the enzyme is quantitatively assayed in additional blood spots or serum. A pilot study has been initiated with samples obtained by the Commonwealth of Virginia for phenylketonuria testing.

Virtual screening methods as tools for drug lead discovery from large chemical libraries.

PubMed

Ma, X H; Zhu, F; Liu, X; Shi, Z; Zhang, J X; Yang, S Y; Wei, Y Q; Chen, Y Z

2012-01-01

Virtual screening methods have been developed and explored as useful tools for searching drug lead compounds from chemical libraries, including large libraries that have become publically available. In this review, we discussed the new developments in exploring virtual screening methods for enhanced performance in searching large chemical libraries, their applications in screening libraries of ~ 1 million or more compounds in the last five years, the difficulties in their applications, and the strategies for further improving these methods.

[Screening methods for mild cognitive impairment in primary care].

PubMed

Freire Pérez, Alberto

2017-06-01

Diagnosis of mild cognitive impairment (MCI) is always clinical and screening methods only indicate that the patient has a higher risk of this condition. In MCI, there is a slight decline in some cognitive abilities that does not affect activities of daily living and therefore does not produce social or occupational disability. The definitive diagnosis of MCI requires a considerable time investment that is very rarely possible to provide in primary care (PC) consultations. Hence the need for PC physicians to employ rapid and simple screening methods (brief cognitive assessment -BCA-) that allow objective identification of patients likely to have MCI in a few minutes. This article reviews the BCA tools that can truly be applied in less than 10 minutes. The phototest is a brief screening tool that is easy to use and interpret by physicians and is well accepted by patients. Consequently, it is one of the most useful tests in PC for screening of both MCI and dementia. In addition to BCA, instrumental activities of daily living scales should also be applied to differentiate MCI from dementia. Copyright © 2017 Sociedad Española de Geriatría y Gerontología. Publicado por Elsevier España, S.L.U. All rights reserved.

Anthropometric methods for obesity screening in schoolchildren: the Ouro Preto Study.

PubMed

Cándido, A P C; Alosta, J P S; Oliveira, C T; Freitas, R N; Freitas, S N; Machado-Coelho, G L L

2012-01-01

Childhood obesity is increasing dramatically in last decades. To evaluate the usefulness of body mass index (BMI), skinfold thickness (ST), waist circumference (WC), and foot-to-foot bioelectrical impedance (BIA-FF) for screening for obesity in mixed-race population, using the tetrapolar bioelectrical impedance (BIA-T) technique as reference method. A cross-sectional-based population study was performed in the city of Ouro Preto, Brazil, in 2006. Schoolchildren aged 6-15 years (n = 788) was randomly selected according to age and sex stratified by the proportion of students in each schools of the city. Nonparametric receiver operating characteristic (ROC) analysis was used to define the sensitivity and specificity for each method studied using the tetrapolar method as reference. The BMI and the BIA-FF were the most suitable for adiposity screening in pre-pubertal and pubertal stages because they present a better balance between sensitivity and specificity, and smaller misclassification. For post-pubertal boys, the BF-ST-D was the best body fat assessment method. The results suggest that BIA-FF and BMI are choice methods for obesity screening in mixed population and that the method choice for body fat screening must be done according to sexual maturity of boys and girls. The present study demonstrates the need to perform studies in wider mixed-race population to determine anthropometric parameters and to examine the predictive ability of methods and cut-offs here elucidated in the development of obesity.

Using pre-screening methods for an effective and reliable site characterization at megasites.

PubMed

Algreen, Mette; Kalisz, Mariusz; Stalder, Marcel; Martac, Eugeniu; Krupanek, Janusz; Trapp, Stefan; Bartke, Stephan

2015-10-01

This paper illustrates the usefulness of pre-screening methods for an effective characterization of polluted sites. We applied a sequence of site characterization methods to a former Soviet military airbase with likely fuel and benzene, toluene, ethylbenzene, and xylene (BTEX) contamination in shallow groundwater and subsoil. The methods were (i) phytoscreening with tree cores; (ii) soil gas measurements for CH4, O2, and photoionization detector (PID); (iii) direct-push with membrane interface probe (MIP) and laser-induced fluorescence (LIF) sensors; (iv) direct-push sampling; and (v) sampling from soil and from groundwater monitoring wells. Phytoscreening and soil gas measurements are rapid and inexpensive pre-screening methods. Both indicated subsurface pollution and hot spots successfully. The direct-push sensors yielded 3D information about the extension and the volume of the subsurface plume. This study also expanded the applicability of tree coring to BTEX compounds and tested the use of high-resolution direct-push sensors for light hydrocarbons. Comparison of screening results to results from conventional soil and groundwater sampling yielded in most cases high rank correlation and confirmed the findings. The large-scale application of non- or low-invasive pre-screening can be of help in directing and focusing the subsequent, more expensive investigation methods. The rapid pre-screening methods also yielded useful information about potential remediation methods. Overall, we see several benefits of a stepwise screening and site characterization scheme, which we propose in conclusion.

An Efficient Variable Screening Method for Effective Surrogate Models for Reliability-Based Design Optimization

DTIC Science & Technology

2014-04-01

surrogate model generation is difficult for high -dimensional problems, due to the curse of dimensionality. Variable screening methods have been...a variable screening model was developed for the quasi-molecular treatment of ion-atom collision [16]. In engineering, a confidence interval of...for high -level radioactive waste [18]. Moreover, the design sensitivity method can be extended to the variable screening method because vital

Lignin as a facilitator, not a barrier, during saccharification by brown rot fungi

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schilling, Jonathan S.; Tschirner, Ulrike; Blanchette, Robert A

2012-11-28

This research focused on the biology of a group of wood-degrading fungi that cause brown rot in wood, with particular attention to the potential to mimic this biological approach ex situ for bioprocessing lignocellulosic biomass. Supported by the long-standing theory that these fungi use a two-step oxidative/enzymatic approach during brown rot, our team’s objectives were as follows: 1) to determine the discrete timing of lignin modifications, 2) to correlate these alterations with biocatalyst efficiency and ingress into plant cell walls, and 3) to reproduce modifications prior to saccharification for efficient bioprocessing. The core findings of our research were that 1)more » lignin modifications occur nearly coincident with enzyme secretion during brown rot and 2) there is no specificity to the benefit that a brown rot pretreatment has on the efficacy of cellulases – it is a general enhancement best predicted by chemical changes to lignin and side-chain hemicellulose sugars. In our work, this meant we could attain and predict broad improvements in saccharification using commercial cellulase cocktails, in some cases more than three-fold of that in untreated biomass. This project was completed with minimal variance from the original project management plan (PMP), resulting in fourteen presentations and posters, four peer-reviewed publications, and one additional publication now in review. The publications have been valuable to other scientists working toward similar goals and have been cited in thirteen peer-reviewed publications written by others since 2010. We are working with ADM to advance application options for industry, building on the lessons learned during this DOE award period.« less

Method of saccharifying cellulose

DOEpatents

Johnson, E.A.; Demain, A.L.; Madia, A.

1983-05-13

A method is disclosed of saccharifying cellulose by incubation with the cellulase of Clostridium thermocellum in a broth containing an efficacious amount of thiol reducing agent. Other incubation parameters which may be advantageously controlled to stimulate saccharification include the concentration of alkaline earth salts, pH, temperature, and duration. By the method of the invention, even native crystalline cellulose such as that found in cotton may be completely saccharified.

A spectrophotometric screening method for avermectin oxidizing microorganisms.

PubMed

Wang, Yuan-Shan; Hu, Qi-Wei; Zheng, Xing-Chang; Zhang, Jian-Fen; Zheng, Yu-Guo

2017-04-01

A spectrophotometric screening method for avermectin oxidizing microbes by determination of 4″-oxo-avermectin was established based on the reaction between 4″-oxo-avermectin and 2,4-dinitrophenylhydrazine. Combined with a gradient HPLC assay, microorganisms capable of regioselectively oxidizing avermectin to 4″-oxo-avermectin were successfully obtained by this method. Copyright © 2017 Elsevier B.V. All rights reserved.

Comparison of high-titer lactic acid fermentation from NaOH- and NH3-H2O2-pretreated corncob by Bacillus coagulans using simultaneous saccharification and fermentation.

PubMed

Zhang, Zhenting; Xie, Yuejiao; He, Xiaolan; Li, Xinli; Hu, Jinlong; Ruan, Zhiyong; Zhao, Shumiao; Peng, Nan; Liang, Yunxiang

2016-11-17

Lignocellulose is one of the most abundant renewable feedstocks that has attracted considerable attention as a substrate for biofuel and biochemical production. One such biochemical product, lactic acid, is an important fermentation product because of its great potential for the production of biodegradable and biocompatible polylactic acid. High-titer lactic acid production from lignocellulosic materials has been achieved recently; however, it requires biodetoxification or results in large amounts of waste washing water. In this study, we employed two alkaline pretreatment methods and compared their effects on lactic acid fermentation of pretreated corncob by Bacillus coagulans LA204 using fed-batch simultaneous saccharification and fermentation under non-sterile conditions. The lactic acid titer, yield, and productivity from 16% (w/w) NaOH-pretreated and washed corncob were 122.99 g/L, 0.77 g/g corncob, and 1.37 g/L/h, respectively, and from 16% NH 3 -H 2 O 2 -pretreated and washed corncob were 118.60 g/L, 0.74 g/g corncob, and 1.32 g/L/h, respectively. Importantly, the lactic acid titer, yield, and productivity from 18.4% NH 3 -H 2 O 2 -pretreated and unwashed corncob by using fed-batch simultaneous saccharification and fermentation reached 79.47 g/L, 0.43 g/g corncob, and 1.10 g/L/h, respectively, demonstrating that this method is possible for industrial applications and saves washing water.

Comparison of high-titer lactic acid fermentation from NaOH- and NH3-H2O2-pretreated corncob by Bacillus coagulans using simultaneous saccharification and fermentation

PubMed Central

Zhang, Zhenting; Xie, Yuejiao; He, Xiaolan; Li, Xinli; Hu, Jinlong; Ruan, Zhiyong; Zhao, Shumiao; Peng, Nan; Liang, Yunxiang

2016-01-01

Lignocellulose is one of the most abundant renewable feedstocks that has attracted considerable attention as a substrate for biofuel and biochemical production. One such biochemical product, lactic acid, is an important fermentation product because of its great potential for the production of biodegradable and biocompatible polylactic acid. High-titer lactic acid production from lignocellulosic materials has been achieved recently; however, it requires biodetoxification or results in large amounts of waste washing water. In this study, we employed two alkaline pretreatment methods and compared their effects on lactic acid fermentation of pretreated corncob by Bacillus coagulans LA204 using fed-batch simultaneous saccharification and fermentation under non-sterile conditions. The lactic acid titer, yield, and productivity from 16% (w/w) NaOH-pretreated and washed corncob were 122.99 g/L, 0.77 g/g corncob, and 1.37 g/L/h, respectively, and from 16% NH3-H2O2-pretreated and washed corncob were 118.60 g/L, 0.74 g/g corncob, and 1.32 g/L/h, respectively. Importantly, the lactic acid titer, yield, and productivity from 18.4% NH3-H2O2-pretreated and unwashed corncob by using fed-batch simultaneous saccharification and fermentation reached 79.47 g/L, 0.43 g/g corncob, and 1.10 g/L/h, respectively, demonstrating that this method is possible for industrial applications and saves washing water. PMID:27853308

Evaluation of Relationships between Growth Rate, Tree Size, Lignocellulose Composition, and Enzymatic Saccharification in Interspecific Corymbia Hybrids and Parental Taxa.

PubMed

Healey, Adam L; Lee, David J; Lupoi, Jason S; Papa, Gabriella; Guenther, Joel M; Corno, Luca; Adani, Fabrizio; Singh, Seema; Simmons, Blake A; Henry, Robert J

2016-01-01

In order for a lignocellulosic bioenergy feedstock to be considered sustainable, it must possess a high rate of growth to supply biomass for conversion. Despite the desirability of a fast growth rate for industrial application, it is unclear what effect growth rate has on biomass composition or saccharification. We characterized Klason lignin, glucan, and xylan content with response to growth in Corymbia interspecific F1 hybrid families (HF) and parental species Corymbia torelliana and C. citriodora subspecies variegata and measured the effects on enzymatic hydrolysis from hydrothermally pretreated biomass. Analysis of biomass composition within Corymbia populations found similar amounts of Klason lignin content (19.7-21.3%) among parental and hybrid populations, whereas glucan content was clearly distinguished within C. citriodora subspecies variegata (52%) and HF148 (60%) as compared to other populations (28-38%). Multiple linear regression indicates that biomass composition is significantly impacted by tree size measured at the same age, with Klason lignin content increasing with diameter breast height (DBH) (+0.12% per cm DBH increase), and glucan and xylan typically decreasing per DBH cm increase (-0.7 and -0.3%, respectively). Polysaccharide content within C. citriodora subspecies variegata and HF-148 were not significantly affected by tree size. High-throughput enzymatic saccharification of hydrothermally pretreated biomass found significant differences among Corymbia populations for total glucose production from biomass, with parental Corymbia torelliana and hybrids HF-148 and HF-51 generating the highest amounts of glucose (~180 mg/g biomass, respectively), with HF-51 undergoing the most efficient glucan-to-glucose conversion (74%). Based on growth rate, biomass composition, and further optimization of enzymatic saccharification yield, high production Corymbia hybrid trees are potentially suitable for fast-rotation bioenergy or biomaterial production.

Evaluation of Relationships between Growth Rate, Tree Size, Lignocellulose Composition, and Enzymatic Saccharification in Interspecific Corymbia Hybrids and Parental Taxa

PubMed Central

Healey, Adam L.; Lee, David J.; Lupoi, Jason S.; Papa, Gabriella; Guenther, Joel M.; Corno, Luca; Adani, Fabrizio; Singh, Seema; Simmons, Blake A.; Henry, Robert J.

2016-01-01

In order for a lignocellulosic bioenergy feedstock to be considered sustainable, it must possess a high rate of growth to supply biomass for conversion. Despite the desirability of a fast growth rate for industrial application, it is unclear what effect growth rate has on biomass composition or saccharification. We characterized Klason lignin, glucan, and xylan content with response to growth in Corymbia interspecific F1 hybrid families (HF) and parental species Corymbia torelliana and C. citriodora subspecies variegata and measured the effects on enzymatic hydrolysis from hydrothermally pretreated biomass. Analysis of biomass composition within Corymbia populations found similar amounts of Klason lignin content (19.7–21.3%) among parental and hybrid populations, whereas glucan content was clearly distinguished within C. citriodora subspecies variegata (52%) and HF148 (60%) as compared to other populations (28–38%). Multiple linear regression indicates that biomass composition is significantly impacted by tree size measured at the same age, with Klason lignin content increasing with diameter breast height (DBH) (+0.12% per cm DBH increase), and glucan and xylan typically decreasing per DBH cm increase (-0.7 and -0.3%, respectively). Polysaccharide content within C. citriodora subspecies variegata and HF-148 were not significantly affected by tree size. High-throughput enzymatic saccharification of hydrothermally pretreated biomass found significant differences among Corymbia populations for total glucose production from biomass, with parental Corymbia torelliana and hybrids HF-148 and HF-51 generating the highest amounts of glucose (~180 mg/g biomass, respectively), with HF-51 undergoing the most efficient glucan-to-glucose conversion (74%). Based on growth rate, biomass composition, and further optimization of enzymatic saccharification yield, high production Corymbia hybrid trees are potentially suitable for fast-rotation bioenergy or biomaterial production

Evaluation of Relationships between Growth Rate, Tree Size, Lignocellulose Composition, and Enzymatic Saccharification in Interspecific Corymbia Hybrids and Parental Taxa

DOE PAGES

Healey, Adam L.; Lee, David J.; Lupoi, Jason S.; ...

2016-11-18

In order for a lignocellulosic bioenergy feedstock to be considered sustainable,it must possess a high rate of growth to supply biomass for conversion. Despite the desirability of a fast growth rate for industrial application,it is unclear what effect growth rate has on biomass composition or saccharification. We characterized Klason lignin,glucan,and xylan content with response to growth in Corymbia interspecific F1 hybrid families (HF) and parental species Corymbia torelliana and C. citriodora subspecies variegata and measured the effects on enzymatic hydrolysis from hydrothermally pretreated biomass. Analysis of biomass composition within Corymbia populations found similar amounts of Klason lignin content (19.7–21.3%) amongmore » parental and hybrid populations,whereas glucan content was clearly distinguished within C. citriodora subspecies variegata (52%) and HF148 (60%) as compared to other populations (28–38%). Multiple linear regression indicates that biomass composition is significantly impacted by tree size measured at the same age,with Klason lignin content increasing with diameter breast height (DBH) (+0.12% per cm DBH increase),and glucan and xylan typically decreasing per DBH cm increase (-0.7 and -0.3%,respectively). Polysaccharide content within C. citriodora subspecies variegata and HF-148 were not significantly affected by tree size. High-throughput enzymatic saccharification of hydrothermally pretreated biomass found significant differences among Corymbia populations for total glucose production from biomass,with parental Corymbia torelliana and hybrids HF-148 and HF-51 generating the highest amounts of glucose (~180 mg/g biomass,respectively),with HF-51 undergoing the most efficient glucan-to-glucose conversion (74%). Based on growth rate,biomass composition,and further optimization of enzymatic saccharification yield,high production Corymbia hybrid trees are potentially suitable for fast-rotation bioenergy or biomaterial production.« less

Evaluation of Relationships between Growth Rate, Tree Size, Lignocellulose Composition, and Enzymatic Saccharification in Interspecific Corymbia Hybrids and Parental Taxa

DOE Office of Scientific and Technical Information (OSTI.GOV)

Healey, Adam L.; Lee, David J.; Lupoi, Jason S.

In order for a lignocellulosic bioenergy feedstock to be considered sustainable,it must possess a high rate of growth to supply biomass for conversion. Despite the desirability of a fast growth rate for industrial application,it is unclear what effect growth rate has on biomass composition or saccharification. We characterized Klason lignin,glucan,and xylan content with response to growth in Corymbia interspecific F1 hybrid families (HF) and parental species Corymbia torelliana and C. citriodora subspecies variegata and measured the effects on enzymatic hydrolysis from hydrothermally pretreated biomass. Analysis of biomass composition within Corymbia populations found similar amounts of Klason lignin content (19.7–21.3%) amongmore » parental and hybrid populations,whereas glucan content was clearly distinguished within C. citriodora subspecies variegata (52%) and HF148 (60%) as compared to other populations (28–38%). Multiple linear regression indicates that biomass composition is significantly impacted by tree size measured at the same age,with Klason lignin content increasing with diameter breast height (DBH) (+0.12% per cm DBH increase),and glucan and xylan typically decreasing per DBH cm increase (-0.7 and -0.3%,respectively). Polysaccharide content within C. citriodora subspecies variegata and HF-148 were not significantly affected by tree size. High-throughput enzymatic saccharification of hydrothermally pretreated biomass found significant differences among Corymbia populations for total glucose production from biomass,with parental Corymbia torelliana and hybrids HF-148 and HF-51 generating the highest amounts of glucose (~180 mg/g biomass,respectively),with HF-51 undergoing the most efficient glucan-to-glucose conversion (74%). Based on growth rate,biomass composition,and further optimization of enzymatic saccharification yield,high production Corymbia hybrid trees are potentially suitable for fast-rotation bioenergy or biomaterial production.« less

Randomized Comparison of 3 Methods to Screen for Domestic Violence in Family Practice

PubMed Central

Chen, Ping-Hsin; Rovi, Sue; Washington, Judy; Jacobs, Abbie; Vega, Marielos; Pan, Ko-Yu; Johnson, Mark S.

2007-01-01

PURPOSE We undertook a study to compare 3 ways of administering brief domestic violence screening questionnaires: self-administered questionnaire, medical staff interview, and physician interview. METHODS We conducted a randomized trial of 3 screening protocols for domestic violence in 4 urban family medicine practices with mostly minority patients. We randomly assigned 523 female patients, aged 18 years or older and currently involved with a partner, to 1 of 3 screening protocols. Each included 2 brief screening tools: HITS and WAST-Short. Outcome measures were domestic violence disclosure, patient and clinician comfort with the screening, and time spent screening. RESULTS Overall prevalence of domestic violence was 14%. Most patients (93.4%) and clinicians (84.5%) were comfortable with the screening questions and method of administering them. Average time spent screening was 4.4 minutes. Disclosure rates, patient and clinician comfort with screening, and time spent screening were similar among the 3 protocols. In addition, WAST-Short was validated in this sample of minority women by comparison with HITS and with the 8-item WAST. CONCLUSIONS Domestic violence is common, and we found that most patients and clinicians are comfortable with domestic violence screening in urban family medicine settings. Patient self-administered domestic violence screening is as effective as clinician interview in terms of disclosure, comfort, and time spent screening. PMID:17893385

Effect of pretreatment on simultaneous saccharification and fermentation of hardwood into acetone/butanol

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shah, M.M.; Song, S.K.; Lee, Y.Y.

1991-12-31

The effectiveness of pretreatments on hardwood substrate was investigated in connection with its subsequent conversion by simultaneous saccharification and fermentation (SSF), using Clostridium acetobutylicum. The main objectives of the pretreatment were to achieve efficient separation of lignin from carbohydrates, and to obtain maximum sugar yield on enzymatic hydrolysis of pretreated wood. Two methods have given promising results: (1) supercritical CO{sub 2}-SO{sub 2} treatment, and (2) monoethanolamine (MEA) treatment. The MEA pretreatment removed above 90% of hardwood lignin while retaining 83% of carbohydrates. With CO{sub 2}-SO{sub 2} pretreatment, the degree of lignin separation was lower. Under the scheme of SSF, themore » pretreated hardwood was converted to acetone, butanol, and ethanol (ABE) via single stage processing by cellulose enzyme system and C. acetobutylicum cells. The product yield in the process was such that 15 g of ABE/100 g of dry aspen wood was produced. In the overall process of SSF, the enzymatic hydrolysis was found to be the rate-limiting step. The ability of C. acetobutylicum to metabolize various 6-carbon and 5-carbon sugars resulted in efficient utilization of all available sugars from hardwood.« less

Screening Methods for Metal-Containing Nanoparticles in Water

EPA Science Inventory

Screening-level analysis of water for metal-containing nanoparticles is achieved with single particle-inductively coupled plasma mass spectrometry (SP-ICPMS). This method measures both the concentration of nanoparticles containing an analyte metal and the mass of the metal in eac...

On-site cellulase production and efficient saccharification of corn stover employing cbh2 overexpressing Trichoderma reesei with novel induction system.

PubMed

Li, Yonghao; Zhang, Xiaoyue; Xiong, Liang; Mehmood, Muhammad Aamer; Zhao, Xinqing; Bai, Fengwu

2017-08-01

Although on-site cellulase production offers cost-effective saccharification of lignocellulosic biomass, low enzyme titer is still a barrier for achieving robustness. In the present study, a strain of T. reesei was developed for enhanced production of cellulase via overexpression of Cellobiohydrolase II. Furthermore, optimum enzyme production was achieved using a novel inducer mixture containing synthesized glucose-sophorose (MGD) and alkali pre-treated corn stover (APCS). Within 60h, a remarkably higher cellulase productivity and activity were achieved in the fed-batch fermentation using the optimized ratio of MGD and APCS in the inducer mixture, compared to those reported using cellulosic biomass as the sole inducer. After the enzyme production, APCS was added directly into the fermentation broth at 20% solid loading, which produced 122.5g/L glucose and 40.21g/L xylose, leading to the highest yield reported so far. The improved enzyme titers during on-site cellulase production would benefit cost-competitive saccharification of lignocellulosic biomass. Copyright © 2017 Elsevier Ltd. All rights reserved.

High-throughput method for optimum solubility screening for homogeneity and crystallization of proteins

DOEpatents

Kim, Sung-Hou [Moraga, CA; Kim, Rosalind [Moraga, CA; Jancarik, Jamila [Walnut Creek, CA

2012-01-31

An optimum solubility screen in which a panel of buffers and many additives are provided in order to obtain the most homogeneous and monodisperse protein condition for protein crystallization. The present methods are useful for proteins that aggregate and cannot be concentrated prior to setting up crystallization screens. A high-throughput method using the hanging-drop method and vapor diffusion equilibrium and a panel of twenty-four buffers is further provided. Using the present methods, 14 poorly behaving proteins have been screened, resulting in 11 of the proteins having highly improved dynamic light scattering results allowing concentration of the proteins, and 9 were crystallized.

A novel hybrid organosolv: steam explosion method for the efficient fractionation and pretreatment of birch biomass.

PubMed

Matsakas, Leonidas; Nitsos, Christos; Raghavendran, Vijayendran; Yakimenko, Olga; Persson, Gustav; Olsson, Eva; Rova, Ulrika; Olsson, Lisbeth; Christakopoulos, Paul

2018-01-01

The main role of pretreatment is to reduce the natural biomass recalcitrance and thus enhance saccharification yield. A further prerequisite for efficient utilization of all biomass components is their efficient fractionation into well-defined process streams. Currently available pretreatment methods only partially fulfill these criteria. Steam explosion, for example, excels as a pretreatment method but has limited potential for fractionation, whereas organosolv is excellent for delignification but offers poor biomass deconstruction. In this article, a hybrid method combining the cooking and fractionation of conventional organosolv pretreatment with the implementation of an explosive discharge of the cooking mixture at the end of pretreatment was developed. The effects of various pretreatment parameters (ethanol content, duration, and addition of sulfuric acid) were evaluated. Pretreatment of birch at 200 °C with 60% v/v ethanol and 1% w/w biomass H 2 SO 4 was proven to be the most efficient pretreatment condition yielding pretreated solids with 77.9% w/w cellulose, 8.9% w/w hemicellulose, and 7.0 w/w lignin content. Under these conditions, high delignification of 86.2% was demonstrated. The recovered lignin was of high purity, with cellulose and hemicellulose contents not exceeding 0.31 and 3.25% w/w, respectively, and ash to be < 0.17% w/w in all cases, making it suitable for various applications. The pretreated solids presented high saccharification yields, reaching 68% at low enzyme load (6 FPU/g) and complete saccharification at high enzyme load (22.5 FPU/g). Finally, simultaneous saccharification and fermentation (SSF) at 20% w/w solids yielded an ethanol titer of 80 g/L after 192 h, corresponding to 90% of the theoretical maximum. The novel hybrid method developed in this study allowed for the efficient fractionation of birch biomass and production of pretreated solids with high cellulose and low lignin contents. Moreover, the explosive

Production of ethanol from a mixture of waste paper and kitchen waste via a process of successive liquefaction, presaccharification, and simultaneous saccharification and fermentation.

PubMed

Nishimura, Hiroto; Tan, Li; Kira, Noriko; Tomiyama, Shigeo; Yamada, Kazuo; Sun, Zhao-Yong; Tang, Yue-Qin; Morimura, Shigeru; Kida, Kenji

2017-09-01

Efficient ethanol production from waste paper requires the addition of expensive nutrients. To reduce the production cost of ethanol from waste paper, a study on how to produce ethanol efficiently by adding kitchen waste (potentially as a carbon source, nutrient source, and acidity regulator) to waste paper was performed and a process of successive liquefaction, presaccharification, and simultaneous saccharification and fermentation (L+PSSF) was developed. The individual saccharification performances of waste paper and kitchen waste were not influenced by their mixture. Liquefaction of kitchen waste at 90°C prior to presaccharification and simultaneous saccharification and fermentation (PSSF) was essential for efficient ethanol fermentation. Ethanol at concentrations of 46.6 or 43.6g/l was obtained at the laboratory scale after fermentation for 96h, even without pH adjustment and/or the addition of extra nutrients. Similarly, ethanol at a concentration of 45.5g/l was obtained at the pilot scale after fermentation for 48h. The ethanol concentration of L+PSSF of the mixture of waste paper and kitchen waste was comparable to that of PSSF of waste paper with added nutrients (yeast extract and peptone) and pH adjustment using H 2 SO 4 , indicating that kitchen waste is not only a carbon source but also an excellent nutrient source and acidity regulator for fermentation of the mixture of waste paper and kitchen waste. Copyright © 2017. Published by Elsevier Ltd.

Biomass saccharification is largely enhanced by altering wall polymer features and reducing silicon accumulation in rice cultivars harvested from nitrogen fertilizer supply.

PubMed

Zahoor; Sun, Dan; Li, Ying; Wang, Jing; Tu, Yuanyuan; Wang, Yanting; Hu, Zhen; Zhou, Shiguang; Wang, Lingqiang; Xie, Guosheng; Huang, Jianliang; Alam, Aftab; Peng, Liangcai

2017-11-01

In this study, two rice cultivars were collected from experimental fields with seven nitrogen fertilizer treatments. All biomass samples contained significantly increased cellulose contents and reduced silica levels, with variable amounts of hemicellulose and lignin from different nitrogen treatments. Under chemical (NaOH, CaO, H 2 SO 4 ) and physical (hot water) pretreatments, biomass samples exhibited much enhanced hexoses yields from enzymatic hydrolysis, with high bioethanol production from yeast fermentation. Notably, both degree of polymerization (DP) of cellulose and xylose/arabinose (Xyl/Ara) ratio of hemicellulose were reduced in biomass residues, whereas other wall polymer features (cellulose crystallinity and monolignol proportion) were variable. Integrative analysis indicated that cellulose DP, hemicellulosic Xyl/Ara and silica are the major factors that significantly affect cellulose crystallinity and biomass saccharification. Hence, this study has demonstrated that nitrogen fertilizer supply could largely enhance biomass saccharification in rice cultivars, mainly by reducing cellulose DP, hemicellulosic Xyl/Ara and silica in cell walls. Copyright © 2017 Elsevier Ltd. All rights reserved.

Steam explosion distinctively enhances biomass enzymatic saccharification of cotton stalks by largely reducing cellulose polymerization degree in G. barbadense and G. hirsutum.

PubMed

Huang, Yu; Wei, Xiaoyang; Zhou, Shiguang; Liu, Mingyong; Tu, Yuanyuan; Li, Ao; Chen, Peng; Wang, Yanting; Zhang, Xuewen; Tai, Hongzhong; Peng, Liangcai; Xia, Tao

2015-04-01

In this study, steam explosion pretreatment was performed in cotton stalks, leading to 5-6 folds enhancements on biomass enzymatic saccharification distinctive in Gossypium barbadense and Gossypium hirsutum species. Sequential 1% H2SO4 pretreatment could further increase biomass digestibility of the steam-exploded stalks, and also cause the highest sugar-ethanol conversion rates probably by releasing less inhibitor to yeast fermentation. By comparison, extremely high concentration alkali (16% NaOH) pretreatment with raw stalks resulted in the highest hexoses yields, but it had the lowest sugar-ethanol conversion rates. Characterization of wall polymer features indicated that biomass saccharification was enhanced with steam explosion by largely reducing cellulose DP and extracting hemicelluloses. It also showed that cellulose crystallinity and arabinose substitution degree of xylans were the major factors on biomass digestibility in cotton stalks. Hence, this study has provided the insights into cell wall modification and biomass process technology in cotton stalks and beyond. Copyright © 2015 Elsevier Ltd. All rights reserved.

Recruitment methods employed in the prostate, lung, colorectal, and ovarian cancer screening trial

PubMed Central

Gren, Lisa; Broski, Karen; Childs, Jeffery; Cordes, Jill; Engelhard, Deborah; Gahagan, Betsy; Gamito, Eduard; Gardner, Vivien; Geisser, Mindy; Higgins, Darlene; Jenkins, Victoria; Lamerato, Lois; Lappe, Karen; Lowery, Heidi; McGuire, Colleen; Miedzinski, Mollie; Ogden, Sheryl; Tenorio, Sally; Watt, Gavin; Wohlers, Bonita; Marcus, Pamela

2015-01-01

Background The Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial (PLCO) is a US National Cancer Institute (NCI)-funded randomized controlled trial designed to evaluate whether certain screening tests reduce mortality from prostate, lung, colorectal, and ovarian cancer. To obtain adequate statistical power, it was necessary to enroll over 150,000 healthy volunteers. Recruitment began in 1993 and ended in 2001. Purpose Our goal is to evaluate the success of recruitment methods employed by the 10 PLCO screening centers. We also provide estimates of recruitment yield and cost for our most successful strategy, direct mail. Methods Each screening center selected its own methods of recruitment. Methods changed throughout the recruitment period as needed. For this manuscript, representatives from each screening center provided information on methods utilized and their success. Results In the United States between 1993 and 2001, ten screening centers enrolled 154,934 study participants. Based on participant self-report, an estimated 95% of individuals were recruited by direct mail. Overall, enrollment yield for direct mail was 1.0%. Individual center enrollment yield ranged from 0.7% to 3.8%. Cost per enrolled participant was $9.64–35.38 for direct mail, excluding personnel costs. Limitations Numeric data on recruitment processes were not kept consistently at individual screening centers. Numeric data in this manuscript are based on the experiences of 5 of the 10 centers. Conclusions Direct mail, using rosters of names and addresses from profit and not-for-profit (including government) organizations, was the most successful and most often used recruitment method. Other recruitment strategies, such as community outreach and use of mass media, can be an important adjunct to direct mail in recruiting minority populations. PMID:19254935

Immobilization of indigenous holocellulase on iron oxide (Fe2O3) nanoparticles enhanced hydrolysis of alkali pretreated paddy straw.

PubMed

Kumar, Ajay; Singh, Surender; Tiwari, Rameshwar; Goel, Renu; Nain, Lata

2017-03-01

The holocellulase from Aspergillus niger SH3 was characterized and found to contain 125 proteins including cellulases (26), hemicellulases (21), chitinases (10), esterases (6), amylases (4) and hypothetical protein (32). The crude enzyme was immobilized on five different nanoparticles (NPs) via physical adsorption and covalent coupling methods. The enzyme-nanoparticle complexes (ENC) were screened for protein binding, enzymatic activities and immobilization efficiency. Magnetic enzyme-nanoparticle complexes (MENC) showed higher immobilization efficiency (60-80%) for most of the enzymes. MENC also showed better catalytic efficiencies in term of higher V max and lower K m than free enzyme. Saccharification yields from alkali treated paddy straw were higher (375.39mg/gds) for covalently immobilized MENC than free enzyme (339.99mg/gds). The immobilized enzyme was used for two cycles of saccharification with 55% enzyme recovery. Hence, this study for the first time demonstrated the immobilization of indigenous enzyme and its utilization for saccharification of paddy straw. Copyright © 2016 Elsevier B.V. All rights reserved.

Optimization of a novel sequential alkalic and metal salt pretreatment for enhanced delignification and enzymatic saccharification of corn cobs.

PubMed

Sewsynker-Sukai, Yeshona; Gueguim Kana, E B

2017-11-01

This study presents a sequential sodium phosphate dodecahydrate (Na 3 PO 4 ·12H 2 O) and zinc chloride (ZnCl 2 ) pretreatment to enhance delignification and enzymatic saccharification of corn cobs. The effects of process parameters of Na 3 PO 4 ·12H 2 O concentration (5-15%), ZnCl 2 concentration (1-5%) and solid to liquid ratio (5-15%) on reducing sugar yield from corn cobs were investigated. The sequential pretreatment model was developed and optimized with a high coefficient of determination value (0.94). Maximum reducing sugar yield of 1.10±0.01g/g was obtained with 14.02% Na 3 PO 4 ·12H 2 O, 3.65% ZnCl 2 and 5% solid to liquid ratio. Scanning electron microscopy (SEM) and Fourier Transform Infrared analysis (FTIR) showed major lignocellulosic structural changes after the optimized sequential pretreatment with 63.61% delignification. In addition, a 10-fold increase in the sugar yield was observed compared to previous reports on the same substrate. This sequential pretreatment strategy was efficient for enhancing enzymatic saccharification of corn cobs. Copyright © 2017 Elsevier Ltd. All rights reserved.

Optimization of fermentation parameters for production of ethanol from kinnow waste and banana peels by simultaneous saccharification and fermentation.

PubMed

Sharma, Naresh; Kalra, K L; Oberoi, Harinder Singh; Bansal, Sunil

2007-12-01

A study was taken up to evaluate the role of some fermentation parameters like inoculum concentration, temperature, incubation period and agitation time on ethanol production from kinnow waste and banana peels by simultaneous saccharification and fermentation using cellulase and co-culture of Saccharomyces cerevisiae G and Pachysolen tannophilus MTCC 1077. Steam pretreated kinnow waste and banana peels were used as substrate for ethanol production in the ratio 4:6 (kinnow waste: banana peels). Temperature of 30°C, inoculum size of S. cerevisiae G 6% and (v/v) Pachysolen tannophilus MTCC 1077 4% (v/v), incubation period of 48 h and agitation for the first 24 h were found to be best for ethanol production using the combination of two wastes. The pretreated steam exploded biomass after enzymatic saccharification containing 63 gL(-1) reducing sugars was fermented with both hexose and pentose fermenting yeast strains under optimized conditions resulting in ethanol production, yield and fermentation efficiency of 26.84 gL(-1), 0.426 gg (-1) and 83.52 % respectively. This study could establish the effective utilization of kinnow waste and banana peels for bioethanol production using optimized fermentation parameters.

Challenges for Detecting Valproic Acid in a Nontargeted Urine Drug Screening Method.

PubMed

Pope, Jeffrey D; Black, Marion J; Drummer, Olaf H; Schneider, Hans G

2017-08-01

Valproic acid (VPA) is a widely prescribed medicine, and acute toxicity is possible. As such, it should be included in any nontargeted urine drug screening method. In many published liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS/MS) methods, VPA is usually measured using a pseudo-multiple reaction monitoring (MRM) transition. We investigate a simple ultra-high-performance liquid chromatography-quadrupole time-of-flight (QTof) approach to detect the presence of VPA with more confidence. Three commercially sourced VPA metabolites were characterized and added to a nontargeted high-resolution MS urine drug screening method. All analyses were performed on a Waters Xevo G2-XS LC-QTof in negative electrospray ionization mode. The mass detector was operated in MS mode, and data were processed with UNIFI software. Sixty-eight patient urine samples, which were previously identified by a well-established gas chromatography-MS method as containing VPA, were analyzed on the Waters Xevo G2-XS LC-QTof, to validate this approach. VPA metabolite standards were characterized, and their detection data were added to the broad drug screening library. VPA metabolites were readily detectable in the urine of patients taking VPA. The inclusion of characterized VPA metabolites provides a simple and reliable method enabling the detection of VPA in nontargeted urine drug screening.

A Triangulation Method for Identifying Hydrostratigraphic Locations of Well Screens

DOE Office of Scientific and Technical Information (OSTI.GOV)

Whiteside, T. S.

2015-01-31

A method to identify the hydrostratigraphic location of well screens was developed using triangulation with known locations. This method was applied to all of the monitor wells being used to develop the new GSA groundwater model. Results from this method are closely aligned with those from an alternate method which uses a mesh surface.

A new mass screening method for methylmercury poisoning using mercury-volatilizing bacteria from Minamata Bay.

PubMed

Nakamura, K; Naruse, I; Takizawa, Y

1999-09-01

A simplified mass screening method for methylmercury exposure was developed using methylmercury-volatilizing bacteria from Minamata Bay. Some bacteria can transform methylmercury into mercury vapor. Most mercury in the hair is methylmercury, which is readily extracted with HCl solution. Black spots are formed on X-ray film due to the reduction of Ag(+) emulsion with mercury vapor produced by methylmercury-volatilizing bacteria. By exploiting these characteristics, a screening method was developed, whereby the fur of rats injected with methylmercury chloride formed clear black spots on X-ray film, whereas the fur of rats injected with saline did not. Subsequently, 50 human hair samples were examined using this mass screening method. The method identified people who had high mercury concentration, over 20 microg/g. A few thousand hair samples may be screened in a day using this method because it is rapid, simple, and economical. This method, therefore, enables screening of persons with methylmercury poisoning in mercury-polluted areas. Copyright 1999 Academic Press.

A Quantum-Based Similarity Method in Virtual Screening.

PubMed

Al-Dabbagh, Mohammed Mumtaz; Salim, Naomie; Himmat, Mubarak; Ahmed, Ali; Saeed, Faisal

2015-10-02

One of the most widely-used techniques for ligand-based virtual screening is similarity searching. This study adopted the concepts of quantum mechanics to present as state-of-the-art similarity method of molecules inspired from quantum theory. The representation of molecular compounds in mathematical quantum space plays a vital role in the development of quantum-based similarity approach. One of the key concepts of quantum theory is the use of complex numbers. Hence, this study proposed three various techniques to embed and to re-represent the molecular compounds to correspond with complex numbers format. The quantum-based similarity method that developed in this study depending on complex pure Hilbert space of molecules called Standard Quantum-Based (SQB). The recall of retrieved active molecules were at top 1% and top 5%, and significant test is used to evaluate our proposed methods. The MDL drug data report (MDDR), maximum unbiased validation (MUV) and Directory of Useful Decoys (DUD) data sets were used for experiments and were represented by 2D fingerprints. Simulated virtual screening experiment show that the effectiveness of SQB method was significantly increased due to the role of representational power of molecular compounds in complex numbers forms compared to Tanimoto benchmark similarity measure.

Saccharification and liquefaction of cassava starch: an alternative source for the production of bioethanol using amylolytic enzymes by double fermentation process

PubMed Central

2014-01-01

Background Cassava starch is considered as a potential source for the commercial production of bioethanol because of its availability and low market price. It can be used as a basic source to support large-scale biological production of bioethanol using microbial amylases. With the progression and advancement in enzymology, starch liquefying and saccharifying enzymes are preferred for the conversion of complex starch polymer into various valuable metabolites. These hydrolytic enzymes can selectively cleave the internal linkages of starch molecule to produce free glucose which can be utilized to produce bioethanol by microbial fermentation. Results In the present study, several filamentous fungi were screened for production of amylases and among them Aspergillus fumigatus KIBGE-IB33 was selected based on maximum enzyme yield. Maximum α-amylase, amyloglucosidase and glucose formation was achieved after 03 days of fermentation using cassava starch. After salt precipitation, fold purification of α-amylase and amyloglucosidase increased up to 4.1 and 4.2 times with specific activity of 9.2 kUmg-1 and 393 kUmg-1, respectively. Concentrated amylolytic enzyme mixture was incorporated in cassava starch slurry to give maximum glucose formation (40.0 gL-1), which was further fermented using Saccharomyces cerevisiae into bioethanol with 84.0% yield. The distillate originated after recovery of bioethanol gave 53.0% yield. Conclusion An improved and effective dual enzymatic starch degradation method is designed for the production of bioethanol using cassava starch. The technique developed is more profitable due to its fast liquefaction and saccharification approach that was employed for the formation of glucose and ultimately resulted in higher yields of alcohol production. PMID:24885587

Surface electromyography as a screening method for evaluation of dysphagia and odynophagia

PubMed Central

Vaiman, Michael; Eviatar, Ephraim

2009-01-01

Objective Patients suspected of having swallowing disorders, could highly benefit from simple diagnostic screening before being referred to specialist evaluations. The article analyzes various instrumental methods of dysphagia assessment, introduces surface electromyography (sEMG) to carry out rapid assessment of such patients, and debates proposed suggestions for sEMG screening protocol in order to identify abnormal deglutition. Data sources Subject related books and articles from 1813 to 2007 were obtained through library search, MEDLINE (1949–2007) and EMBASE (1975–2007). Methods Specifics steps for establishing the protocol for applying the technique for screening purposes (e.g., evaluation of specific muscles), the requirements for diagnostic sEMG equipment, the sEMG technique itself, and defining the tests suitable for assessing deglutition (e.g., saliva, normal, and excessive swallows and uninterrupted drinking of water) are presented in detail. SEMG is compared with other techniques in terms of cost, timing, involvement of radiation, etc. Results According to the published data, SEMG of swallowing is a simple and reliable method for screening and preliminary differentiation among dysphagia and odynophagia of various origins. This noninvasive radiation-free examination has a low level of discomfort, and is simple, time-saving and inexpensive to perform. The major weakness of the method seems to be inability for precise diagnostic of neurologically induced dysphagia. Conclusion With standardization of the technique and an established normative database, sEMG might serve as a reliable screening method for optimal patient management but cannot serve for proper investigation of neurogenic dysphagia. PMID:19232090

Optimization of High Solids Dilute Acid Hydrolysis of Spent Coffee Ground at Mild Temperature for Enzymatic Saccharification and Microbial Oil Fermentation.

PubMed

Wang, Hui-Min David; Cheng, Yu-Shen; Huang, Chi-Hao; Huang, Chia-Wei

2016-10-01

Soluble coffee, being one of the world's most popular consuming drinks, produces a considerable amount of spent coffee ground (SCG) along with its production. The SCG could function as a potential lignocellulosic feedstock for production of bioproducts. The objective of this study is to investigate the possible optimal condition of dilute acid hydrolysis (DAH) at high solids and mild temperature condition to release the reducing sugars from SCG. The optimal condition was found to be 5.3 % (w/w) sulfuric acid concentration and 118 min reaction time. Under the optimal condition, the mean yield of reducing sugars from enzymatic saccharification of defatted SCG acid hydrolysate was 563 mg/g. The SCG hydrolysate was then successfully applied to culture Lipomyces starkeyi for microbial oil fermentation without showing any inhibition. The results suggested that dilute acid hydrolysis followed by enzymatic saccharification has the great potential to convert SCG carbohydrates to reducing sugars. This study is useful for the further developing of biorefinery using SCG as feedstock at a large scale.

Dynamic modeling and analyses of simultaneous saccharification and fermentation process to produce bio-ethanol from rice straw.

PubMed

Ko, Jordon; Su, Wen-Jun; Chien, I-Lung; Chang, Der-Ming; Chou, Sheng-Hsin; Zhan, Rui-Yu

2010-02-01

The rice straw, an agricultural waste from Asians' main provision, was collected as feedstock to convert cellulose into ethanol through the enzymatic hydrolysis and followed by the fermentation process. When the two process steps are performed sequentially, it is referred to as separate hydrolysis and fermentation (SHF). The steps can also be performed simultaneously, i.e., simultaneous saccharification and fermentation (SSF). In this research, the kinetic model parameters of the cellulose saccharification process step using the rice straw as feedstock is obtained from real experimental data of cellulase hydrolysis. Furthermore, this model can be combined with a fermentation model at high glucose and ethanol concentrations to form a SSF model. The fermentation model is based on cybernetic approach from a paper in the literature with an extension of including both the glucose and ethanol inhibition terms to approach more to the actual plants. Dynamic effects of the operating variables in the enzymatic hydrolysis and the fermentation models will be analyzed. The operation of the SSF process will be compared to the SHF process. It is shown that the SSF process is better in reducing the processing time when the product (ethanol) concentration is high. The means to improve the productivity of the overall SSF process, by properly using aeration during the batch operation will also be discussed.

FIELD ANALYTICAL SCREENING PROGRAM: PCP METHOD - INNOVATIVE TECHNOLOGY EVALUATION REPORT

EPA Science Inventory

The Field Analytical Screening Program (FASP) pentachlorophenol (PCP) method uses a gas chromatograph (GC) equipped with a megabore capillary column and flame ionization detector (FID) and electron capture detector (ECD) to identify and quantify PCP. The FASP PCP method is design...

Comparative analysis of machine learning methods in ligand-based virtual screening of large compound libraries.

PubMed

Ma, Xiao H; Jia, Jia; Zhu, Feng; Xue, Ying; Li, Ze R; Chen, Yu Z

2009-05-01

Machine learning methods have been explored as ligand-based virtual screening tools for facilitating drug lead discovery. These methods predict compounds of specific pharmacodynamic, pharmacokinetic or toxicological properties based on their structure-derived structural and physicochemical properties. Increasing attention has been directed at these methods because of their capability in predicting compounds of diverse structures and complex structure-activity relationships without requiring the knowledge of target 3D structure. This article reviews current progresses in using machine learning methods for virtual screening of pharmacodynamically active compounds from large compound libraries, and analyzes and compares the reported performances of machine learning tools with those of structure-based and other ligand-based (such as pharmacophore and clustering) virtual screening methods. The feasibility to improve the performance of machine learning methods in screening large libraries is discussed.

[Computerized monitoring for integrated cervical screening. Rationale, methods and indicators of participation].

PubMed

Bucchi, L; Pierri, C; Caprara, L; Cortecchia, S; De Lillo, M; Bondi, A

2003-02-01

This paper presents a computerised system for the monitoring of integrated cervical screening, i.e. the integration of spontaneous Pap smear practice into organised screening. The general characteristics of the system are described, including background and rationale (integrated cervical screening in European countries, impact of integration on monitoring, decentralised organization of screening and levels of monitoring), general methods (definitions, sections, software description, and setting of application), and indicators of participation (distribution by time interval since previous Pap smear, distribution by screening sector--organised screening centres vs public and private clinical settings--, distribution by time interval between the last two Pap smears, and movement of women between the two screening sectors). Also, the paper reports the results of the application of these indicators in the general database of the Pathology Department of Imola Health District in northern Italy.

FIELD ANALYTICAL SCREENING PROGRAM: PCB METHOD - INNOVATIVE TECHNOLOGY REPORT

EPA Science Inventory

This innovative technology evaluation report (ITER) presents information on the demonstration of the U.S. Environmental Protection Agency (EPA) Region 7 Superfund Field Analytical Screening Program (FASP) method for determining polychlorinated biphenyl (PCB) contamination in soil...

[Screening for risk of child abuse and neglect. A practicable method?].

PubMed

Kindler, H

2010-10-01

Selective primary prevention programs for child abuse and neglect depend on risk screening instruments that have the goal of systematically identifying families who can profit most from early help. Based on a systematic review of longitudinal studies, a set of established risk factors for early child abuse and neglect is presented. Nearly half of the items included in screening instruments can be seen as validated. Available studies indicate a high sensitivity of risk screening instruments. Positive predictive values, however, are low. Overall, the use of risk screening instruments in the area of primary prevention for families at risk represents a feasible method, as long as stigmatizing effects can be avoided and participating families also benefit beyond preventing endangerment.

Thermo-chemical pretreatment and enzymatic hydrolysis for enhancing saccharification of catalpa sawdust.

PubMed

Jin, Shuguang; Zhang, Guangming; Zhang, Panyue; Li, Fan; Fan, Shiyang; Li, Juan

2016-04-01

To improve the reducing sugar production from catalpa sawdust, thermo-chemical pretreatments were examined and the chemicals used including NaOH, Ca(OH)2, H2SO4, and HCl. The hemicellulose solubilization and cellulose crystallinity index (CrI) were significantly increased after thermo-alkaline pretreatments, and the thermo-Ca(OH)2 pretreatment showed the best improvement for reducing sugar production comparing to other three pretreatments. The conditions of thermo-Ca(OH)2 pretreatment and enzymatic hydrolysis were systematically optimized. Under the optimal conditions, the reducing sugar yield increased by 1185.7% comparing to the control. This study indicates that the thermo-Ca(OH)2 pretreatment is ideal for the saccharification of catalpa sawdust and that catalpa sawdust is a promising raw material for biofuel. Copyright © 2016 Elsevier Ltd. All rights reserved.

Simultaneous Saccharification and Fermentation of Sugar Beet Pulp with Mixed Bacterial Cultures for Lactic Acid and Propylene Glycol Production.

PubMed

Berlowska, Joanna; Cieciura, Weronika; Borowski, Sebastian; Dudkiewicz, Marta; Binczarski, Michal; Witonska, Izabela; Otlewska, Anna; Kregiel, Dorota

2016-10-17

Research into fermentative production of lactic acid from agricultural by-products has recently concentrated on the direct conversion of biomass, whereby pure sugars are replaced with inexpensive feedstock in the process of lactic acid production. In our studies, for the first time, the source of carbon used is sugar beet pulp, generated as a by-product of industrial sugar production. In this paper, we focus on the simultaneous saccharification of lignocellulosic biomass and fermentation of lactic acid, using mixed cultures with complementary assimilation profiles. Lactic acid is one of the primary platform chemicals, and can be used to synthesize a wide variety of useful products, including green propylene glycol. A series of controlled batch fermentations was conducted under various conditions, including pretreatment with enzymatic hydrolysis. Inoculation was performed in two sequential stages, to avoid carbon catabolite repression. Biologically-synthesized lactic acid was catalytically reduced to propylene glycol over 5% Ru/C. The highest lactic acid yield was obtained with mixed cultures. The yield of propylene glycol from the biological lactic acid was similar to that obtained with a water solution of pure lactic acid. Our results show that simultaneous saccharification and fermentation enables generation of lactic acid, suitable for further chemical transformations, from agricultural residues.

Simultaneous saccharification and fermentation of ground corn stover for the production of fuel ethanol using Phanerochaete chrysosporium, Gloeophyllum trabeum, Saccharomyces cerevisiae, and Escherichia coli K011.

PubMed

Vincent, Micky; Pometto, Anthony L; van Leeuwen, J Hans

2011-07-01

Enzymatic saccharification of corn stover using Phanerochaete chrysosporium and Gloeophyllum trabeum and subsequent fermentation of the saccharification products to ethanol by Saccharomyces cerevisiae and Escherichia coli K011 were achieved. Prior to simultaneous saccharification and fermentation (SSF) for ethanol production, solid-state fermentation was performed for four days on ground corn stover using either P. chrysosporium or G. trabeum to induce in situ cellulase production. During SSF with S. cerevisiae or E. coli, ethanol production was the highest on day 4 for all samples. For corn stover treated with P. chrysosporium, the conversion to ethanol was 2.29 g/100 g corn stover with S. cerevisiae as the fermenting organism, whereas for the sample inoculated with E. coli K011, the ethanol production was 4.14 g/100 g corn stover. Corn stover treated with G. trabeum showed a conversion 1.90 and 4.79 g/100 g corn stover with S. cerevisiae and E. coli K011 as the fermenting organisms, respectively. Other fermentation co-products, such as acetic acid and lactic acid, were also monitored. Acetic acid production ranged between 0.45 and 0.78 g/100 g corn stover, while no lactic acid production was detected throughout the 5 days of SSF. The results of our experiment suggest that it is possible to perform SSF of corn stover using P. chrysosporium, G. trabeum, S. cerevisiae and E. coli K011 for the production of fuel ethanol.

Flow method and apparatus for screening chemicals using micro x-ray fluorescence

DOEpatents

Warner, Benjamin P [Los Alamos, NM; Havrilla, George J [Los Alamos, NM; Miller, Thomasin C [Bartlesville, OK; Lewis, Cris [Los Alamos, NM; Mahan, Cynthia A [Los Alamos, NM; Wells, Cyndi A [Los Alamos, NM

2009-04-14

Method and apparatus for screening chemicals using micro x-ray fluorescence. A method for screening a mixture of potential pharmaceutical chemicals for binding to at least one target binder involves flow-separating a solution of chemicals and target binders into separated components, exposing them to an x-ray excitation beam, detecting x-ray fluorescence signals from the components, and determining from the signals whether or not a binding event between a chemical and target binder has occurred.

Flow method and apparatus for screening chemicals using micro x-ray fluorescence

DOEpatents

Warner, Benjamin P [Los Alamos, NM; Havrilla, George J [Los Alamos, NM; Miller, Thomasin C [Bartlesville, OK; Lewis, Cris [Los Alamos, NM; Mahan, Cynthia A [Los Alamos, NM; Wells, Cyndi A [Los Alamos, NM

2011-04-26

Method and apparatus for screening chemicals using micro x-ray fluorescence. A method for screening a mixture of potential pharmaceutical chemicals for binding to at least one target binder involves flow separating a solution of chemicals and target binders into separated components, exposing them to an x-ray excitation beam, detecting x-ray fluorescence signals from the components, and determining from the signals whether or not a binding event between a chemical and target binder has occurred.

A Systematic Evaluation of Field-Based Screening Methods for the Assessment of Anterior Cruciate Ligament (ACL) Injury Risk.

PubMed

Fox, Aaron S; Bonacci, Jason; McLean, Scott G; Spittle, Michael; Saunders, Natalie

2016-05-01

Laboratory-based measures provide an accurate method to identify risk factors for anterior cruciate ligament (ACL) injury; however, these methods are generally prohibitive to the wider community. Screening methods that can be completed in a field or clinical setting may be more applicable for wider community use. Examination of field-based screening methods for ACL injury risk can aid in identifying the most applicable method(s) for use in these settings. The objective of this systematic review was to evaluate and compare field-based screening methods for ACL injury risk to determine their efficacy of use in wider community settings. An electronic database search was conducted on the SPORTDiscus™, MEDLINE, AMED and CINAHL databases (January 1990-July 2015) using a combination of relevant keywords. A secondary search of the same databases, using relevant keywords from identified screening methods, was also undertaken. Studies identified as potentially relevant were independently examined by two reviewers for inclusion. Where consensus could not be reached, a third reviewer was consulted. Original research articles that examined screening methods for ACL injury risk that could be undertaken outside of a laboratory setting were included for review. Two reviewers independently assessed the quality of included studies. Included studies were categorized according to the screening method they examined. A description of each screening method, and data pertaining to the ability to prospectively identify ACL injuries, validity and reliability, recommendations for identifying 'at-risk' athletes, equipment and training required to complete screening, time taken to screen athletes, and applicability of the screening method across sports and athletes were extracted from relevant studies. Of 1077 citations from the initial search, a total of 25 articles were identified as potentially relevant, with 12 meeting all inclusion/exclusion criteria. From the secondary search, eight

FIELD SCREENING METHODS FOR HAZARDOUS WASTES AND TOXIC CHEMICALS

EPA Science Inventory

The purpose of this document is to present the technical papers that were presented at the Second International Symposium on Field Screening Methods for Hazardous Wastes and Toxic Chemicals. ixty platform presentations were made and included in one of ten sessions: hemical sensor...

Biochemical characterization and synergism of cellulolytic enzyme system from Chaetomium globosum on rice straw saccharification.

PubMed

Wanmolee, Wanwitoo; Sornlake, Warasirin; Rattanaphan, Nakul; Suwannarangsee, Surisa; Laosiripojana, Navadol; Champreda, Verawat

2016-11-21

Efficient hydrolysis of lignocellulosic materials to sugars for conversion to biofuels and chemicals is a key step in biorefinery. Designing an active saccharifying enzyme system with synergy among their components is considered a promising approach. In this study, a lignocellulose-degrading enzyme system of Chaetomium globosum BCC5776 (CG-Cel) was characterized for its activity and proteomic profiles, and synergism with accessory enzymes. The highest cellulase productivity of 0.40 FPU/mL was found for CG-Cel under the optimized submerged fermentation conditions on 1% (w/v) EPFB (empty palm fruit bunch), 2% microcrystalline cellulose (Avicel®) and 1% soybean meal (SBM) at 30 °C, pH 5.8 for 6 d. CG-Cel worked optimally at 50-60 °C in an acidic pH range. Proteomics analysis by LC/MS/MS revealed a complex enzyme system composed of core cellulases and accessory hydrolytic/non-hydrolytic enzymes attacking plant biopolymers. A synergistic enzyme system comprising the CG-Cel, a β-glucosidase (Novozyme® 188) and a hemicellulase Accellerase® XY was optimized on saccharification of alkaline-pretreated rice straw by a mixture design approach. Applying a full cubic model, the optimal ratio of ternary enzyme mixture containing CG-Cel: Novozyme® 188: Accellerase® XY of 44.4:20.6:35.0 showed synergistic enhancement on reducing sugar yield with a glucose releasing efficiency of 256.4 mg/FPU, equivalent to a 2.9 times compared with that from CG-Cel alone. The work showed an approach for developing an active synergistic enzyme system based on the newly characterized C. globosum for lignocellulose saccharification and modification in bio-industries.

Newborn screening for cystic fibrosis in Wisconsin: comparison of biochemical and molecular methods.

PubMed

Gregg, R G; Simantel, A; Farrell, P M; Koscik, R; Kosorok, M R; Laxova, A; Laessig, R; Hoffman, G; Hassemer, D; Mischler, E H; Splaingard, M

1997-06-01

To evaluate neonatal screening for cystic fibrosis (CF), including study of the screening procedures and characteristics of false-positive infants, over the past 10 years in Wisconsin. An important objective evolving from the original design has been to compare use of a single-tier immunoreactive trypsinogen (IRT) screening method with that of a two-tier method using IRT and analyses of samples for the most common cystic fibrosis transmembrane regulator (CFTR) (DeltaF508) mutation. We also examined the benefit of including up to 10 additional CFTR mutations in the screening protocol. From 1985 to 1994, using either the IRT or IRT/DNA protocol, 220 862 and 104 308 neonates, respectively, were screened for CF. For the IRT protocol, neonates with an IRT >/=180 ng/mL were considered positive, and the standard sweat chloride test was administered to determine CF status. For the IRT/DNA protocol, samples from the original dried-blood specimen on the Guthrie card of neonates with an IRT >/=110 ng/mL were tested for the presence of the DeltaF508 CFTR allele, and if the DNA test revealed one or two DeltaF508 alleles, a sweat test was obtained. Both screening procedures had very high specificity. The sensitivity tended to be higher with the IRT/DNA protocol, but the differences were not statistically significant. The positive predictive value of the IRT/DNA screening protocol was 15.2% compared with 6.4% if the same samples had been screened by the IRT method. Assessment of the false-positive IRT/DNA population revealed that the two-tier method eliminates the disproportionate number of infants with low Apgar scores and also the high prevalence of African-Americans identified previously in our study of newborns with high IRT levels. We found that 55% of DNA-positive CF infants were homozygous for DeltaF508 and 40% had one DeltaF508 allele. Adding analyses for 10 more CFTR mutations has only a small effect on the sensitivity but is likely to add significantly to the cost of

A comparative rapid and sensitive method to screen l-asparaginase producing fungi.

PubMed

Dhale, Mohan A; Mohan-Kumari, H Puttananjaiah

2014-07-01

Fungi are well known to produce various industrial enzymes and secondary metabolites with different colours. Fungi producing l-asparaginase enzyme are conventionally screened on medium containing phenol red (PR). The contrast between enzyme-hydrolysed zone and unhydrolysed l-asparagine is not very evident and distinct in medium containing PR and bromothymol blue (BB) due to coloured secondary metabolite production. Thus, PR and BB limit and affect the detection and screening method. In the present investigation, an improved method for screening is reported by comparing with PR and BB, wherein methyl red (MR) is incorporated as pH indicator. The enzyme activity was distinctly observed (red and light-yellow) in MR incorporated medium compared to PR and BB. Copyright © 2014 Elsevier B.V. All rights reserved.

High titer ethanol production from simultaneous enzymatic saccharification and fermentation of aspen at high solids : a comparison between SPORL and dilute acid pretreatments

Treesearch

J.Y. Zhu; R. Gleisner; C.T. Scott; X.L. Luo; S. Tian

2011-01-01

Native aspen (Populus tremuloides) was pretreated using sulfuric acid and sodium bisulfite (SPORL) and dilute sulfuric acid alone (DA). Simultaneous enzymatic saccharification and fermentation (SSF) was conducted at 18% solids using commercial enzymes with cellulase loadings ranging from 6 to 15 FPU/g glucan and Saccharomyces cerevisiae Y5. Compared with DA...

Rapid screening of guar gum using portable Raman spectral identification methods.

PubMed

Srivastava, Hirsch K; Wolfgang, Steven; Rodriguez, Jason D

2016-01-25

Guar gum is a well-known inactive ingredient (excipient) used in a variety of oral pharmaceutical dosage forms as a thickener and stabilizer of suspensions and as a binder of powders. It is also widely used as a food ingredient in which case alternatives with similar properties, including chemically similar gums, are readily available. Recent supply shortages and price fluctuations have caused guar gum to come under increasing scrutiny for possible adulteration by substitution of cheaper alternatives. One way that the U.S. FDA is attempting to screen pharmaceutical ingredients at risk for adulteration or substitution is through field-deployable spectroscopic screening. Here we report a comprehensive approach to evaluate two field-deployable Raman methods--spectral correlation and principal component analysis--to differentiate guar gum from other gums. We report a comparison of the sensitivity of the spectroscopic screening methods with current compendial identification tests. The ability of the spectroscopic methods to perform unambiguous identification of guar gum compared to other gums makes them an enhanced surveillance alternative to the current compendial identification tests, which are largely subjective in nature. Our findings indicate that Raman spectral identification methods perform better than compendial identification methods and are able to distinguish guar gum from other gums with 100% accuracy for samples tested by spectral correlation and principal component analysis. Published by Elsevier B.V.

Ultrasonic pretreatment for enhanced saccharification and fermentation of ethanol production from corn

NASA Astrophysics Data System (ADS)

Montalbo-Lomboy, Melissa T.

The 21st Century human lifestyle has become heavily dependent on hydrocarbon inputs. Energy demand and the global warming effects due to the burning of fossil fuels have continued to increase. Rising awareness of the negative environmental and economic impacts of hydrocarbon dependence has led to a resurgence of interest in renewable energy sources such as ethanol. Fuel ethanol is known to be a cleaner and renewable source of energy relative to gasoline. Many studies have agreed that fuel ethanol has reduced greenhouse gas (GHG) emissions and has larger overall energy benefits compared to gasoline. Currently, the majority of the fuel ethanol in the United States is produced from corn using dry-grind milling process. The typical dry-grind ethanol plant incorporates jet cooking using steam to cook the corn slurry as pretreatment for saccharification; an energy intensive step. In aiming to reduce energy usage, this study evaluated the use of ultrasonics as an alternative to jet cooking. Ultrasonic batch experiments were conducted using a Branson 2000 Series bench-scale ultrasonic unit operating at a frequency of 20 kHz and a maximum output of 2.2 kW. Corn slurry was sonicated at varying amplitudes from 192 to 320 mumpeak-to-peak(p-p) for 0-40 seconds. Enzyme stability was investigated by adding enzyme (STARGEN(TM)001) before and after sonication. Scanning electron micrograph (SEM) images and particle size distribution analysis showed a nearly 20-fold size reduction by disintegration of corn particles due to ultrasonication. The results also showed a 30% improvement in sugar release of sonicated samples relative to the control group (untreated). The efficiency exceeded 100% in terms of relative energy gain from the additional sugar released due to ultrasonication compared to the ultrasonic energy applied. Interestingly, enzymatic activity was enhanced when sonicated at low and medium power. This result suggested that ultrasonic energy did not denature the enzymes

Optimization of enzymatic hydrolysis for ethanol production by simultaneous saccharification and fermentation of wastepaper.

PubMed

Sangkharak, Kanokphorn

2011-11-01

The present study investigated the development of high sugar production by optimization of an enzymatic hydrolysis process using both conventional and statistical methods, as well as the production of ethanol by the selected wastepaper source. Among four sources of pretreated wastepaper including office paper, newspaper, handbills and cardboard, office paper gave the highest values of cellulose (87.12%) and holocelluloses (89.07%). The effects of the amount of wastepaper, the pretreatment method and the type of enzyme on reducing sugar production from office paper were studied using conventional methods. The highest reducing sugar production (1851.28 µg L(-1); 37.03% conversion of glucose) was obtained from the optimal condition containing 40 mg of office paper, pretreated with stream explosion and hydrolysed with the combination of cellulase from Aspergillus niger and Trichoderma viride at the fixed loading rate of 20 FPU g(-1) sample. The effects of interaction of wastepaper amount and enzyme concentration as well as incubation time were studied by a statistical method using central composite design. The optimal medium composition consisted of 43.97 µg L(-1), 28.14 FPU g(-1) sample and 53.73 h of wastepaper, enzyme concentration and incubation time, respectively, and gave the highest amount of sugar production (2184.22 µg L(-1)) and percentage conversion of glucose (43.68%). The ethanol production from pretreated office paper using Saccharomyces cerevisiae in a simultaneous saccharification and fermentation process was 21.02 g L(-1) after 36 h of cultivation, corresponding to an ethanol volumetric production rate of 0.58 g ethanol L(-1) h(-1).

TINS, target immobilized NMR screening: an efficient and sensitive method for ligand discovery.

PubMed

Vanwetswinkel, Sophie; Heetebrij, Robert J; van Duynhoven, John; Hollander, Johan G; Filippov, Dmitri V; Hajduk, Philip J; Siegal, Gregg

2005-02-01

We propose a ligand screening method, called TINS (target immobilized NMR screening), which reduces the amount of target required for the fragment-based approach to drug discovery. Binding is detected by comparing 1D NMR spectra of compound mixtures in the presence of a target immobilized on a solid support to a control sample. The method has been validated by the detection of a variety of ligands for protein and nucleic acid targets (K(D) from 60 to 5000 muM). The ligand binding capacity of a protein was undiminished after 2000 different compounds had been applied, indicating the potential to apply the assay for screening typical fragment libraries. TINS can be used in competition mode, allowing rapid characterization of the ligand binding site. TINS may allow screening of targets that are difficult to produce or that are insoluble, such as membrane proteins.

Of enzyme use in cost-effective high solid simultaneous saccharification and fermentation processes.

PubMed

Sóti, Valentin; Lenaerts, Silvia; Cornet, Iris

2018-03-20

Enzyme cost is considered to be one of the most significant factors defining the final product price in lignocellulose hydrolysis and fermentation. Enzyme immobilization and recycling can be a tool to decrease costs. However, high solid loading is a key factor towards high product titers, and recovery of immobilized enzymes from this thick liquid is often overlooked. This paper aims to evaluate the economic feasibility of immobilized enzymes in simultaneous saccharification and fermentation (SSF) of lignocellulose biomass in general, as well as the recuperation of magnetic immobilized enzymes (m-CLEAs) during high solid loading in simultaneous saccharification, detoxification and fermentation processes (SSDF) of lignocellulose biomass. Enzyme prices were obtained from general cost estimations by Klein-Marcuschamer et al. [Klein-Marcuschamer et al. (2012) Biotechnol. Bioeng. 109, 1083-1087]. During enzyme cost analysis, the influence of inoculum recirculation as well as a shortened fermentation time was explored. Both resulted in 15% decrease of final enzyme product price. Enzyme recuperation was investigated experimentally and 99.5 m/m% of m-CLEAs was recovered from liquid medium in one step, while 88 m/m% could still be recycled from a thick liquid with high solid concentrations (SSF fermentation broth). A mathematical model was constructed to calculate the cost of immobilized and free enzyme utilization and showed that, with current process efficiencies and commercial enzyme prices, the cost reduction obtained by enzyme immobilization can reach around 60% compared to free enzyme utilization, while lower enzyme prices will result in a lower percentage of immobilization related savings, but overall enzyme costs will decrease significantly. These results are applied in a case study, estimating the viability of shifting from sugar to lignocellulose substrate for a 100 t lactic acid fermentation batch. It was concluded that it will only be economically feasible

Cocrystal screening of hydroxybenzamides with benzoic acid derivatives: a comparative study of thermal and solution-based methods.

PubMed

Manin, Alex N; Voronin, Alexander P; Drozd, Ksenia V; Manin, Nikolay G; Bauer-Brandl, Annette; Perlovich, German L

2014-12-18

The main problem occurring at the early stages of cocrystal search is the choice of an effective screening technique. Among the most popular techniques of obtaining cocrystals are crystallization from solution, crystallization from melt and solvent-drop grinding. This paper represents a comparative analysis of the following screening techniques: DSC cocrystal screening method, thermal microscopy and saturation temperature method. The efficiency of different techniques of cocrystal screening was checked in 18 systems. Benzamide and benzoic acid derivatives were chosen as model systems due to their ability to form acid-amide supramolecular heterosynthon. The screening has confirmed the formation of 6 new cocrystals. The screening by the saturation temperature method has the highest screen-out rate but the smallest range of application. DSC screening has a satisfactory accuracy and allows screening over a short time. Thermal microscopy is most efficient as an additional technique used to interpret ambiguous DSC screening results. The study also included an analysis of the influence of solvent type and component solubility on cocrystal formation. Copyright © 2014 Elsevier B.V. All rights reserved.

Comparative Evaluation of Preliminary Screening Methods for Colorectal Cancer in a Mass Program.

PubMed

Ye, Ding; Huang, Qiuchi; Li, Qilong; Jiang, Xiyi; Mamat, Mayila; Tang, Mengling; Wang, Jianbing; Chen, Kun

2017-09-01

The fecal immunochemical test (FIT) has been widely used in preliminary screening for colorectal cancer (CRC). The high-risk factor questionnaire (HRFQ) and quantitative risk-assessment method (QRAM) are recommended for estimating the risk of CRC qualitatively and quantitatively in China. We aimed to prospectively compare the diagnostic values of CRC preliminary screening methods to identify which method is preferable as a screening strategy. Individuals aged 40-74 years old were enrolled in a mass CRC screening program from January 1, 2007 to December 31, 2014, in Jiashan County, Zhejiang Province, China. FIT of two stool specimens at 1-week intervals was performed by laboratory personnel and face-to-face interviews were conducted by trained investigators. Screening data in the program were linked to a CRC surveillance and registry system, and CRC cases reported in the system were regarded as true patients. A total of 96,043 subjects were included. The sensitivity and specificity of FIT for detecting CRC cases were 75.49% (95% CI 69.84-80.39) and 90.36% (95% CI 90.17-90.54), respectively. QRAM was more sensitive (p < 0.001) and less specific (p < 0.001) than HRFQ. The sensitivity and specificity of FIT along with HRFQ were 86.56% (95% CI 81.81-90.22) and 81.37% (95% CI 81.12-81.62), and those of FIT along with QRAM were 88.93% (95% CI 84.47-92.23) and 73.95% (95% CI 73.67-74.23). Our findings suggest that CRC preliminary screening with FIT and QRAM in parallel has high sensitivity and satisfactory specificity, and is a useful strategy in mass screening programs.

Circling motion and screen edges as an alternative input method for on-screen target manipulation.

PubMed

Ka, Hyun W; Simpson, Richard C

2017-04-01

To investigate a new alternative interaction method, called circling interface, for manipulating on-screen objects. To specify a target, the user makes a circling motion around the target. To specify a desired pointing command with the circling interface, each edge of the screen is used. The user selects a command before circling the target. To evaluate the circling interface, we conducted an experiment with 16 participants, comparing the performance on pointing tasks with different combinations of selection method (circling interface, physical mouse and dwelling interface) and input device (normal computer mouse, head pointer and joystick mouse emulator). A circling interface is compatible with many types of pointing devices, not requiring physical activation of mouse buttons, and is more efficient than dwell-clicking. Across all common pointing operations, the circling interface had a tendency to produce faster performance with a head-mounted mouse emulator than with a joystick mouse. The performance accuracy of the circling interface outperformed the dwelling interface. It was demonstrated that the circling interface has the potential as another alternative pointing method for selecting and manipulating objects in a graphical user interface. Implications for Rehabilitation A circling interface will improve clinical practice by providing an alternative pointing method that does not require physically activating mouse buttons and is more efficient than dwell-clicking. The Circling interface can also work with AAC devices.

The identification of and relief from Fe3+ inhibition for both cellulose and cellulase in cellulose saccharification catalyzed by cellulases from Penicillium decumbens.

PubMed

Wang, Mingyu; Mu, Ziming; Wang, Junli; Hou, Shaoli; Han, Lijuan; Dong, Yanmei; Xiao, Lin; Xia, Ruirui; Fang, Xu

2013-04-01

Lignocellulosic biomass is an underutilized, renewable resource that can be converted to biofuels. The key step in this conversion is cellulose saccharification catalyzed by cellulase. In this work, the effect of metal ions on cellulose hydrolysis by cellulases from Penicillium decumbens was reported for the first time. Fe(3+) and Cu(2+) were shown to be inhibitory. Further studies on Fe(3+) inhibition showed the inhibition takes place on both enzyme and substrate levels. Fe(3+) treatment damages cellulases' capability to degrade cellulose and inhibits all major cellulase activities. Fe(3+) treatment also reduces the digestibility of cellulose, due to its oxidation. Treatment of Fe(3+)-treated cellulose with DTT and supplementation of EDTA to saccharification systems partially relieved Fe(3+) inhibition. It was concluded that Fe(3+) inhibition in cellulose degradation is a complicated process in which multiple inhibition events occur, and that relief from Fe(3+) inhibition can be achieved by the supplementation of reducing or chelating agents. Copyright © 2013 Elsevier Ltd. All rights reserved.

Display screen and method of manufacture therefor

NASA Technical Reports Server (NTRS)

Dubin, Matthew B. (Inventor); Larson, Brent D. (Inventor)

2001-01-01

A screen assembly that combines an angle re-distributing prescreen with a conventional diffusion screen is disclosed. The prescreen minimizes or eliminates the sensitivity of the screen assembly to projector location. The diffusion screen provides other desirable screen characteristics. The prescreen is preferably formed by a collection of light transmitting and refracting elements, preferably spheres 80, partially embedded in a light blocking layer. Toward the back of the spheres 80 are effective apertures 82 where the light blocking layer 81 is absent or at least thinner than in other regions toward the side of the spheres. The projected image enters spheres 80 through the effective apertures 82, and exits the spheres 80 centered orientationally about the normal to the lens axis. The re-oriented light rays then enter the diffusion screen for viewing.

Apparatus and method for radioactive waste screening

DOEpatents

Akers, Douglas W.; Roybal, Lyle G.; Salomon, Hopi; Williams, Charles Leroy

2012-09-04

An apparatus and method relating to screening radioactive waste are disclosed for ensuring that at least one calculated parameter for the measurement data of a sample falls within a range between an upper limit and a lower limit prior to the sample being packaged for disposal. The apparatus includes a radiation detector configured for detecting radioactivity and radionuclide content of the of the sample of radioactive waste and generating measurement data in response thereto, and a collimator including at least one aperture to direct a field of view of the radiation detector. The method includes measuring a radioactive content of a sample, and calculating one or more parameters from the radioactive content of the sample.

Biomass enzymatic saccharification is determined by the non-KOH-extractable wall polymer features that predominately affect cellulose crystallinity in corn.

PubMed

Jia, Jun; Yu, Bin; Wu, Leiming; Wang, Hongwu; Wu, Zhiliang; Li, Ming; Huang, Pengyan; Feng, Shengqiu; Chen, Peng; Zheng, Yonglian; Peng, Liangcai

2014-01-01

Corn is a major food crop with enormous biomass residues for biofuel production. Due to cell wall recalcitrance, it becomes essential to identify the key factors of lignocellulose on biomass saccharification. In this study, we examined total 40 corn accessions that displayed a diverse cell wall composition. Correlation analysis showed that cellulose and lignin levels negatively affected biomass digestibility after NaOH pretreatments at p<0.05 & 0.01, but hemicelluloses did not show any significant impact on hexoses yields. Comparative analysis of five standard pairs of corn samples indicated that cellulose and lignin should not be the major factors on biomass saccharification after pretreatments with NaOH and H2SO4 at three concentrations. Notably, despite that the non-KOH-extractable residues covered 12%-23% hemicelluloses and lignin of total biomass, their wall polymer features exhibited the predominant effects on biomass enzymatic hydrolysis including Ara substitution degree of xylan (reverse Xyl/Ara) and S/G ratio of lignin. Furthermore, the non-KOH-extractable polymer features could significantly affect lignocellulose crystallinity at p<0.05, leading to a high biomass digestibility. Hence, this study could suggest an optimal approach for genetic modification of plant cell walls in bioenergy corn.

Biomass Enzymatic Saccharification Is Determined by the Non-KOH-Extractable Wall Polymer Features That Predominately Affect Cellulose Crystallinity in Corn

PubMed Central

Wu, Leiming; Wang, Hongwu; Wu, Zhiliang; Li, Ming; Huang, Pengyan; Feng, Shengqiu; Chen, Peng; Zheng, Yonglian; Peng, Liangcai

2014-01-01

Corn is a major food crop with enormous biomass residues for biofuel production. Due to cell wall recalcitrance, it becomes essential to identify the key factors of lignocellulose on biomass saccharification. In this study, we examined total 40 corn accessions that displayed a diverse cell wall composition. Correlation analysis showed that cellulose and lignin levels negatively affected biomass digestibility after NaOH pretreatments at p<0.05 & 0.01, but hemicelluloses did not show any significant impact on hexoses yields. Comparative analysis of five standard pairs of corn samples indicated that cellulose and lignin should not be the major factors on biomass saccharification after pretreatments with NaOH and H2SO4 at three concentrations. Notably, despite that the non-KOH-extractable residues covered 12%–23% hemicelluloses and lignin of total biomass, their wall polymer features exhibited the predominant effects on biomass enzymatic hydrolysis including Ara substitution degree of xylan (reverse Xyl/Ara) and S/G ratio of lignin. Furthermore, the non-KOH-extractable polymer features could significantly affect lignocellulose crystallinity at p<0.05, leading to a high biomass digestibility. Hence, this study could suggest an optimal approach for genetic modification of plant cell walls in bioenergy corn. PMID:25251456

Barriers to Breast and Cervical Cancer Screening in Singapore: a Mixed Methods Analysis.

PubMed

Malhotra, Chetna; Bilger, Marcel; Liu, Joy; Finkelstein, Eric

2016-01-01

In order to increase breast and cervical cancer screening uptake in Singapore, women's perceived barriers to screening need to be identified and overcome. Using data from both focus groups and surveys, we aimed to assess perceived barriers and motivations for breast and cervical cancer screening. We conducted 8 focus groups with 64 women, using thematic analysis to identify overarching themes related to women's attitudes towards screening. Based on recurring themes from focus groups, several hypotheses regarding potential barriers and motivations to screen were generated and tested through a national survey of 801 women aged 25-64. Focus group participants had misconceptions related to screening, believing that the procedures were painful. Cost was an issue, as well as efficacy and fatalism. By identifying barriers to and motivators for screening through a mixed-method design that has both nuance and external validity, this study offers valuable suggestions to policymakers to improve breast and cervical cancer screening uptake in Singapore.

Microfluidic glycosyl hydrolase screening for biomass-to-biofuel conversion.

PubMed

Bharadwaj, Rajiv; Chen, Zhiwei; Datta, Supratim; Holmes, Bradley M; Sapra, Rajat; Simmons, Blake A; Adams, Paul D; Singh, Anup K

2010-11-15

The hydrolysis of biomass to fermentable sugars using glycosyl hydrolases such as cellulases and hemicellulases is a limiting and costly step in the conversion of biomass to biofuels. Enhancement in hydrolysis efficiency is necessary and requires improvement in both enzymes and processing strategies. Advances in both areas in turn strongly depend on the progress in developing high-throughput assays to rapidly and quantitatively screen a large number of enzymes and processing conditions. For example, the characterization of various cellodextrins and xylooligomers produced during the time course of saccharification is important in the design of suitable reactors, enzyme cocktail compositions, and biomass pretreatment schemes. We have developed a microfluidic-chip-based assay for rapid and precise characterization of glycans and xylans resulting from biomass hydrolysis. The technique enables multiplexed separation of soluble cellodextrins and xylose oligomers in around 1 min (10-fold faster than HPLC). The microfluidic device was used to elucidate the mode of action of Tm_Cel5A, a novel cellulase from hyperthermophile Thermotoga maritima . The results demonstrate that the cellulase is active at 80 °C and effectively hydrolyzes cellodextrins and ionic-liquid-pretreated switchgrass and Avicel to glucose, cellobiose, and cellotriose. The proposed microscale approach is ideal for quantitative large-scale screening of enzyme libraries for biomass hydrolysis, for development of energy feedstocks, and for polysaccharide sequencing.

Synergistic effect of Aspergillus niger and Trichoderma reesei enzyme sets on the saccharification of wheat straw and sugarcane bagasse.

PubMed

van den Brink, Joost; Maitan-Alfenas, Gabriela Piccolo; Zou, Gen; Wang, Chengshu; Zhou, Zhihua; Guimarães, Valéria Monteze; de Vries, Ronald P

2014-10-01

Plant-degrading enzymes can be produced by fungi on abundantly available low-cost plant biomass. However, enzymes sets after growth on complex substrates need to be better understood, especially with emphasis on differences between fungal species and the influence of inhibitory compounds in plant substrates, such as monosaccharides. In this study, Aspergillus niger and Trichoderma reesei were evaluated for the production of enzyme sets after growth on two "second generation" substrates: wheat straw (WS) and sugarcane bagasse (SCB). A. niger and T. reesei produced different sets of (hemi-)cellulolytic enzymes after growth on WS and SCB. This was reflected in an overall strong synergistic effect in releasing sugars during saccharification using A. niger and T. reesei enzyme sets. T. reesei produced less hydrolytic enzymes after growth on non-washed SCB. The sensitivity to non-washed plant substrates was not reduced by using CreA/Cre1 mutants of T. reesei and A. niger with a defective carbon catabolite repression. The importance of removing monosaccharides for producing enzymes was further underlined by the decrease in hydrolytic activities with increased glucose concentrations in WS media. This study showed the importance of removing monosaccharides from the enzyme production media and combining T. reesei and A. niger enzyme sets to improve plant biomass saccharification. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Screening methods for post-stroke visual impairment: a systematic review.

PubMed

Hanna, Kerry Louise; Hepworth, Lauren Rachel; Rowe, Fiona

2017-12-01

assess all potential post-stroke visual impairments. The current tools screen for only a number of potential stroke-related impairments, which means many visual defects may be missed. The sensitivity of those which screen for all impairments is significantly lowered when patients are unable to report their visual symptoms. Future research is required to develop a tool capable of assessing stroke patients which encompasses all potential visual deficits and can also be easily performed by both the patients and administered by health care professionals in order to ensure all stroke survivors with visual impairment are accurately identified and managed. Implications for Rehabilitation Over 65% of stroke survivors will suffer from a visual impairment, whereas 45% of stroke units do not assess vision. Visual impairment significantly reduces the quality of life, such as being unable to return to work, driving and depression. This review outlines the available screening methods to accurately identify stroke survivors with visual impairments. Identifying visual impairment after stroke can aid general rehabilitation and thus, improve the quality of life for these patients.

Metal accumulation by sunflower (Helianthus annuus L.) and the efficacy of its biomass in enzymatic saccharification

PubMed Central

Dhiman, Saurabh Sudha; Zhao, Xin; Li, Jinglin; Kim, Dongwook; Kalia, Vipin C.; Kim, In-Won; Kim, Jae Young; Lee, Jung-Kul

2017-01-01

Accumulation of metal contaminants in soil as a result of various industrial and anthropogenic activities has reduced soil fertility significantly. Phytoextraction of metal contaminants can improve soil fertility and provide inexpensive feedstock for biorefineries. We investigated the hyperaccumulation capacity of sunflower (Helianthus annuus) biomass by cultivating these plants in various concentrations of metal contaminants. Sunflowers were grown in soils contaminated with various levels of heavy metals (10–2,000 mg/kg dry soil). The degree of metal uptake by different parts of the biomass and the residual concentration in the soil were estimated through inductively coupled plasma mass spectrometry. An almost 2.5-fold hyperaccumulation of Zn2+ was observed in the leaf and flower biomass compared with the concentration in the soil. For the subsequent saccharification of biomass with hyperaccumulated contaminants, a fungal lignocellulosic consortium was used. The fungal consortium cocktail retained more than 95% filter paper activity with 100 mM Ni2+ ions even after 36 h. The highest saccharification yield (SY, 87.4%) was observed with Ni2+ as the contaminant (10 mg/kg dry wt), whereas Pb2+ (251.9 mg/kg dry wt) was the strongest inhibitor of biomass hydrolysis, resulting in only a 30% SY. Importantly, the enzyme cocktail produced by the fungal consortium resulted in almost the same SY (%) as that obtained from a combination of commercial cellulase and β-glucosidase. Significant sugar conversion (61.7%) from H. annuus biomass hydrolysate occurred, resulting in the production of 11.4 g/L of bioethanol. This is the first study to assess the suitability of phytoremediated sunflower biomass for bioethanol production. PMID:28437478

Metal accumulation by sunflower (Helianthus annuus L.) and the efficacy of its biomass in enzymatic saccharification.

PubMed

Dhiman, Saurabh Sudha; Zhao, Xin; Li, Jinglin; Kim, Dongwook; Kalia, Vipin C; Kim, In-Won; Kim, Jae Young; Lee, Jung-Kul

2017-01-01

Accumulation of metal contaminants in soil as a result of various industrial and anthropogenic activities has reduced soil fertility significantly. Phytoextraction of metal contaminants can improve soil fertility and provide inexpensive feedstock for biorefineries. We investigated the hyperaccumulation capacity of sunflower (Helianthus annuus) biomass by cultivating these plants in various concentrations of metal contaminants. Sunflowers were grown in soils contaminated with various levels of heavy metals (10-2,000 mg/kg dry soil). The degree of metal uptake by different parts of the biomass and the residual concentration in the soil were estimated through inductively coupled plasma mass spectrometry. An almost 2.5-fold hyperaccumulation of Zn2+ was observed in the leaf and flower biomass compared with the concentration in the soil. For the subsequent saccharification of biomass with hyperaccumulated contaminants, a fungal lignocellulosic consortium was used. The fungal consortium cocktail retained more than 95% filter paper activity with 100 mM Ni2+ ions even after 36 h. The highest saccharification yield (SY, 87.4%) was observed with Ni2+ as the contaminant (10 mg/kg dry wt), whereas Pb2+ (251.9 mg/kg dry wt) was the strongest inhibitor of biomass hydrolysis, resulting in only a 30% SY. Importantly, the enzyme cocktail produced by the fungal consortium resulted in almost the same SY (%) as that obtained from a combination of commercial cellulase and β-glucosidase. Significant sugar conversion (61.7%) from H. annuus biomass hydrolysate occurred, resulting in the production of 11.4 g/L of bioethanol. This is the first study to assess the suitability of phytoremediated sunflower biomass for bioethanol production.

Optimization of sodium hydroxide pretreatment and enzyme loading for efficient hydrolysis of rice straw to improve succinate production by metabolically engineered Escherichia coli KJ122 under simultaneous saccharification and fermentation.

PubMed

Sawisit, Apichai; Jampatesh, Surawee; Jantama, Sirima Suvarnakuta; Jantama, Kaemwich

2018-07-01

Rice straw was pretreated with sodium hydroxide (NaOH) before subsequent use for succinate production by Escherichia coli KJ122 under simultaneous saccharification and fermentation (SSF). The NaOH pretreated rice straw was significantly enhanced lignin removal up to 95%. With the optimized enzyme loading of 4% cellulase complex + 0.5% xylanase (endo-glucanase 67 CMC-U/g, β-glucosidase 26 pNG-U/g and xylanase 18 CMC-U/g dry biomass), total sugar conversion reached 91.7 ± 0.8% (w/w). The physicochemical analysis of NaOH pretreated rice straw indicated dramatical changes in its structure, thereby favoring enzymatic saccharification. In batch SSF, succinate production of 69.8 ± 0.3 g/L with yield and productivity of 0.84 g/g pretreated rice straw and 0.76 ± 0.02 g/L/h, respectively, was obtained. Fed-batch SSF significantly improved succinate concentration and productivity to 103.1 ± 0.4 g/L and 1.37 ± 0.07 g/L/h with a comparable yield. The results demonstrated a feasibility of sequential saccharification and fermentation of rice straw as a promising process for succinate production in industrial scale. Copyright © 2018 Elsevier Ltd. All rights reserved.

Comparison of three noninvasive methods for hemoglobin screening of blood donors.

PubMed

Ardin, Sergey; Störmer, Melanie; Radojska, Stela; Oustianskaia, Larissa; Hahn, Moritz; Gathof, Birgit S

2015-02-01

To prevent phlebotomy of anemic individuals and to ensure hemoglobin (Hb) content of the blood units, Hb screening of blood donors before donation is essential. Hb values are mostly evaluated by measurement of capillary blood obtained from fingerstick. Rapid noninvasive methods have recently become available and may be preferred by donors and staff. The aim of this study was to evaluate for the first time all different noninvasive methods for Hb screening. Blood donors were screened for Hb levels in three different trials using three different noninvasive methods (Haemospect [MBR Optical Systems GmbH & Co. KG], NBM 200 [LMB Technology GmbH], Pronto-7 [Masimo Europe Ltd]) in comparison to the established fingerstick method (CompoLab Hb [Fresenius Kabi GmbH]) and to levels obtained from venous samples on a cell counter (Sysmex [Sysmex Europe GmbH]) as reference. The usability of the noninvasive methods was assessed with an especially developed survey. Technical failures occurred by using the Pronto-7 due to nail polish, skin color, or ambient light. The NBM 200 also showed a high sensitivity to ambient light and noticeably lower Hb levels for women than obtained from the Sysmex. The statistical analysis showed the following bias and standard deviation of differences of all methods in comparison to the venous results: Haemospect, -0.22 ± 1.24; NBM, 200 -0.12 ± 1.14; Pronto-7, -0.50 ± 0.99; and CompoLab Hb, -0.53 ± 0.81. Noninvasive Hb tests represent an attractive alternative by eliminating pain and reducing risks of blood contamination. The main problem for generating reliable results seems to be preanalytical variability in sampling. Despite the sensitivity to environmental stress, all methods are suitable for Hb measurement. © 2014 AABB.

A fast boosting-based screening method for large-scale association study in complex traits with genetic heterogeneity.

PubMed

Wang, Lu-Yong; Fasulo, D

2006-01-01

Genome-wide association study for complex diseases will generate massive amount of single nucleotide polymorphisms (SNPs) data. Univariate statistical test (i.e. Fisher exact test) was used to single out non-associated SNPs. However, the disease-susceptible SNPs may have little marginal effects in population and are unlikely to retain after the univariate tests. Also, model-based methods are impractical for large-scale dataset. Moreover, genetic heterogeneity makes the traditional methods harder to identify the genetic causes of diseases. A more recent random forest method provides a more robust method for screening the SNPs in thousands scale. However, for more large-scale data, i.e., Affymetrix Human Mapping 100K GeneChip data, a faster screening method is required to screening SNPs in whole-genome large scale association analysis with genetic heterogeneity. We propose a boosting-based method for rapid screening in large-scale analysis of complex traits in the presence of genetic heterogeneity. It provides a relatively fast and fairly good tool for screening and limiting the candidate SNPs for further more complex computational modeling task.

Saccharification efficiencies of multi-enzyme complexes produced by aerobic fungi.

PubMed

Badhan, Ajay; Huang, Jiangli; Wang, Yuxi; Abbott, D Wade; Di Falco, Marcos; Tsang, Adrian; McAllister, Tim

2018-05-24

In the present study, we have characterized high molecular weight multi-enzyme complexes in two commercial enzymes produced by Trichoderma reesei (Spezyme CP) and Penicillium funiculosum (Accellerase XC). We successfully identified 146-1000 kDa complexes using Blue native polyacrylamide gel electrophoresis (BN-PAGE) to fractionate the protein profile in both preparations. Identified complexes dissociated into lower molecular weight constituents when loaded on SDS PAGE. Unfolding of the secondary structure of multi-enzyme complexes with trimethylamine (pH >10) suggested that they were not a result of unspecific protein aggregation. Cellulase (CMCase) profiles of extracts of BN-PAGE fractionated protein bands confirmed cellulase activity within the multi-enzyme complexes. A microassay was used to identify protein bands that promoted high levels of glucose release from barley straw. Those with high saccharification yield were subjected to LC-MS analysis to identify the principal enzymatic activities responsible. The results suggest that secretion of proteins by aerobic fungi leads to the formation of high molecular weight multi-enzyme complexes that display activity against carboxymethyl cellulose and barley straw. Copyright © 2018. Published by Elsevier B.V.

Enzymatic saccharification of biologically pre-treated wheat straw with white-rot fungi.

PubMed

Dias, Albino A; Freitas, Gil S; Marques, Guilhermina S M; Sampaio, Ana; Fraga, Irene S; Rodrigues, Miguel A M; Evtuguin, Dmitry V; Bezerra, Rui M F

2010-08-01

Wheat straw was submitted to a pre-treatment by the basidiomycetous fungi Euc-1 and Irpex lacteus, aiming to improve the accessibility of cellulose towards enzymatic hydrolysis via previous selective bio-delignification. This allowed the increase of substrate saccharification nearly four and three times while applying the basidiomycetes Euc-1 and I. lacteus, respectively. The cellulose/lignin ratio increased from 2.7 in the untreated wheat straw to 5.9 and 4.6 after the bio-treatment by the basidiomycetes Euc-1 and I. lacteus, respectively, thus evidencing the highly selective lignin biodegradation. The enzymatic profile of both fungi upon bio-treatment of wheat straw have been assessed including laccase, manganese-dependent peroxidase, lignin peroxidase, carboxymethylcellulase, xylanase, avicelase and feruloyl esterase activities. The difference in efficiency and selectivity of delignification within the two fungi treatments was interpreted in terms of specific lignolytic enzyme profiles and moderate xylanase and cellulolytic activities. (c) 2010 Elsevier Ltd. All rights reserved.

[Methicillin resistance detection in Staphylococcus aureus: comparison between conventional methods and MRSA-Screen latex agglutination technique].

PubMed

Soloaga, R; Corso, A; Gagetti, P; Faccone, D; Galas, M

2004-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) is a significant pathogen that has emerged over the last four decades, causing both nosocomial and community-acquired infections. Rapid and accurate detection of methicillin resistance in S. aureus is important for the use of appropriate antimicrobial therapy and for the control of nosocomial spread of MRSA strains. We evaluated the efficiency of conventional methods for detection of methicillin resistance such as the disk diffusion, agar dilution, oxacillin agar screen test, and the latex agglutination test MRSA-Screen latex, in 100 isolates of S. aureus, 79 mecA positive and 21 mecA negative. The MRSA-Screen latex (Denka Seiken, Niigata, Japón), is a latex agglutination method that detects the presence of PLP-2a, product of mecA gene in S. aureus. The PCR of the mecA gene was used as the "gold standard" for the evaluation of the different methods tested. The percentages of sensitivity and specificity were as follows: disk difusión 97 and 100%, agar dilution 97 and 95%, oxacillin agar screen test 100 and 100%, and MRSA-Screen latex, 100 and 100 %. All methods presented high sensitivity and specificity, but MRSA-Screen latex had the advantage of giving a reliable result, equivalent to PCR, in only 15 minutes.

Novel microscopy-based screening method reveals regulators of contact-dependent intercellular transfer

PubMed Central

Michael Frei, Dominik; Hodneland, Erlend; Rios-Mondragon, Ivan; Burtey, Anne; Neumann, Beate; Bulkescher, Jutta; Schölermann, Julia; Pepperkok, Rainer; Gerdes, Hans-Hermann; Kögel, Tanja

2015-01-01

Contact-dependent intercellular transfer (codeIT) of cellular constituents can have functional consequences for recipient cells, such as enhanced survival and drug resistance. Pathogenic viruses, prions and bacteria can also utilize this mechanism to spread to adjacent cells and potentially evade immune detection. However, little is known about the molecular mechanism underlying this intercellular transfer process. Here, we present a novel microscopy-based screening method to identify regulators and cargo of codeIT. Single donor cells, carrying fluorescently labelled endocytic organelles or proteins, are co-cultured with excess acceptor cells. CodeIT is quantified by confocal microscopy and image analysis in 3D, preserving spatial information. An siRNA-based screening using this method revealed the involvement of several myosins and small GTPases as codeIT regulators. Our data indicates that cellular protrusions and tubular recycling endosomes are important for codeIT. We automated image acquisition and analysis to facilitate large-scale chemical and genetic screening efforts to identify key regulators of codeIT. PMID:26271723

Lignocellulosic butanol production from Napier grass using semi-simultaneous saccharification fermentation.

PubMed

He, Chi-Ruei; Kuo, Yu-Yuan; Li, Si-Yu

2017-05-01

Napier grass is a potential feedstock for biofuel production because of its strong adaptability and wide availability. Compositional analysis has been done on Napier grass which was collected from a local area of Taiwan. By comparing acid- and alkali-pretreatment, it was found that the alkali-pretreatment process is favorable for Napier grass. An overall glucose yield of 0.82g/g-glucose total can be obtained with the combination of alkali-pretreatment (2.5wt% NaOH, 8wt% sample loading, 121°C, and a reaction time of 40min) and enzymatic hydrolysis (40FPU/g-substrate). Semi-simultaneous saccharification fermentation (sSSF) was carried out, where enzymatic hydrolysis and ABE fermentation were operated in the same batch. It was found that after 24-h hydrolysis, followed by 96-h fermentation, the butanol and acetone concentrations reached 9.45 and 4.85g/L, respectively. The butanol yield reached 0.22g/g-sugar glucose+xylose . Finally, the efficiency of butanol production from Napier grass was calculated at 31%. Copyright © 2017 Elsevier Ltd. All rights reserved.

One Question, Multiple Answers: Biochemical and Biophysical Screening Methods Retrieve Deviating Fragment Hit Lists.

PubMed

Schiebel, Johannes; Radeva, Nedyalka; Köster, Helene; Metz, Alexander; Krotzky, Timo; Kuhnert, Maren; Diederich, Wibke E; Heine, Andreas; Neumann, Lars; Atmanene, Cedric; Roecklin, Dominique; Vivat-Hannah, Valérie; Renaud, Jean-Paul; Meinecke, Robert; Schlinck, Nina; Sitte, Astrid; Popp, Franziska; Zeeb, Markus; Klebe, Gerhard

2015-09-01

Fragment-based lead discovery is gaining momentum in drug development. Typically, a hierarchical cascade of several screening techniques is consulted to identify fragment hits which are then analyzed by crystallography. Because crystal structures with bound fragments are essential for the subsequent hit-to-lead-to-drug optimization, the screening process should distinguish reliably between binders and non-binders. We therefore investigated whether different screening methods would reveal similar collections of putative binders. First we used a biochemical assay to identify fragments that bind to endothiapepsin, a surrogate for disease-relevant aspartic proteases. In a comprehensive screening approach, we then evaluated our 361-entry library by using a reporter-displacement assay, saturation-transfer difference NMR, native mass spectrometry, thermophoresis, and a thermal shift assay. While the combined results of these screening methods retrieve 10 of the 11 crystal structures originally predicted by the biochemical assay, the mutual overlap of individual hit lists is surprisingly low, highlighting that each technique operates on different biophysical principles and conditions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Novel method for screening of enteric film coatings properties with magnetic resonance imaging.

PubMed

Dorożyński, Przemysław; Jamróz, Witold; Niwiński, Krzysztof; Kurek, Mateusz; Węglarz, Władysław P; Jachowicz, Renata; Kulinowski, Piotr

2013-11-18

The aim of the study is to present the concept of novel method for fast screening of enteric coating compositions properties without the need of preparation of tablets batches for fluid bed coating. Proposed method involves evaluation of enteric coated model tablets in specially designed testing cell with application of MRI technique. The results obtained in the testing cell were compared with results of dissolution studies of mini-tablets coated in fluid bed apparatus. The method could be useful in early stage of formulation development for screening of film coating properties that will shorten and simplify the development works. Copyright © 2013 Elsevier B.V. All rights reserved.

Simultaneous saccharification of inulin and starch using commercial glucoamylase and the subsequent bioconversion to high titer sorbitol and gluconic acid.

PubMed

An, Kehong; Hu, Fengxian; Bao, Jie

2013-12-01

A new bioprocess for production of sorbitol and gluconic acid from two low-cost feedstocks, inulin and cassava starch, using a commercially available enzyme was proposed in this study. The commercial glucoamylase GA-L NEW from Genencor was found to demonstrate a high inulinase activity for hydrolysis of inulin into fructose and glucose. The glucoamylase was used to replace the expensive and not commercially available inulinase enzyme for simultaneous saccharification of inulin and starch into high titer glucose and fructose hydrolysate. The glucose and fructose in the hydrolysate were converted into sorbitol and gluconic acid using immobilized whole cells of the recombinant Zymomonas mobilis strain. The high gluconic acid concentration of 193 g/L and sorbitol concentration of 180 g/L with the overall yield of 97.3 % were obtained in the batch operations. The present study provided a practical production method of sorbitol and gluconic acid from low cost feedstocks and enzymes.

Production and characterization of multi-polysaccharide degrading enzymes from Aspergillus aculeatus BCC199 for saccharification of agricultural residues.

PubMed

Suwannarangsee, Surisa; Arnthong, Jantima; Eurwilaichitr, Lily; Champreda, Verawat

2014-10-01

Enzymatic hydrolysis of lignocellulosic biomass into fermentable sugars is a key step in the conversion of agricultural by-products to biofuels and value-added chemicals. Utilization of a robust microorganism for on-site production of biomass-degrading enzymes has gained increasing interest as an economical approach for supplying enzymes to biorefinery processes. In this study, production of multi-polysaccharide-degrading enzymes from Aspergillus aculeatus BCC199 by solid-state fermentation was improved through the statistical design approach. Among the operational parameters, yeast extract and soybean meal as well as the nonionic surfactant Tween 20 and initial pH were found as key parameters for maximizing production of cellulolytic and hemicellulolytic enzymes. Under the optimized condition, the production of FPase, endoglucanase, β-glucosidase, xylanase, and β-xylosidase was achieved at 23, 663, 88, 1,633, and 90 units/g of dry substrate, respectively. The multi-enzyme extract was highly efficient in the saccharification of alkaline-pretreated rice straw, corn cob, and corn stover. In comparison with commercial cellulase preparations, the BCC199 enzyme mixture was able to produce remarkable yields of glucose and xylose, as it contained higher relative activities of β-glucosidase and core hemicellulases (xylanase and β-xylosidase). These results suggested that the crude enzyme extract from A. aculeatus BCC199 possesses balanced cellulolytic and xylanolytic activities required for the efficient saccharification of lignocellulosic biomass feedstocks, and supplementation of external β-glucosidase or xylanase was dispensable. The work thus demonstrates the high potential of A. aculeatus BCC199 as a promising producer of lignocellulose-degrading enzymes for the biomass conversion industry.

Characterization of truncated endo-β-1,4-glucanases from a compost metagenomic library and their saccharification potentials.

PubMed

Lee, Jae Pil; Lee, Hyun Woo; Na, Han Beur; Lee, Jun-Hee; Hong, Yeo-Jin; Jeon, Jeong-Min; Kwon, Eun Ju; Kim, Sung Kyum; Kim, Hoon

2018-04-23

A gene encoding an endo-β-1,4-glucanase (Cel6H-f481) was cloned from a compost metagenomic library. The gene, cel6H-f481, was composed of 1446 bp to encode a fused protein of 481 amino acid residues (50,429 Da), i.e., 445 residues (Cel6H-445) from the metagenome, and 36 residues from the pUC19 vector at N-terminus. Cel6H-445 belonged to glycosyl hydrolase (GH) family 6 and showed 71% identity with Actinotalea fermentans endoglucanase with low coverage. Several active bands of truncated forms were observed by activity staining of the crude extract. Major truncated enzymes of 35 (Cel6H-p35) and 23 kDa (Cel6H-p23) were separated by HiTrap Q chromatography. The two enzymes had the same optimum temperature (50 °C) and pH (5.5), but Cel6H-p35 was more thermostable than Cel6H-p23 and other GH6 endoglucanases reported. Both enzymes efficiently hydrolyzed carboxymethyl-cellulose (CMC) and barley β-glucan, but hardly hydrolyzed other substrates tested. The V max of Cel6H-p35 for CMC was 1.4 times greater than that of Cel6H-p23. The addition of the crude enzymes to a commercial enzyme set increased the saccharification of pretreated rice straw powder by up to 30.9%. These results suggest the N-terminal region of Cel6H-p35 contributes to thermostability and specific activity, and that the enzymes might be a useful additive for saccharification. Copyright © 2018 Elsevier B.V. All rights reserved.

Proposal of Screening Method of Sleep Disordered Breathing Using Fiber Grating Vision Sensor

NASA Astrophysics Data System (ADS)

Aoki, Hirooki; Nakamura, Hidetoshi; Nakajima, Masato

Every conventional respiration monitoring technique requires at least one sensor to be attached to the body of the subject during measurement, thereby imposing a sense of restraint that results in aversion against measurements that would last over consecutive days. To solve this problem, we developed a respiration monitoring system for sleepers, and it uses a fiber-grating vision sensor, which is a type of active image sensor to achieve non-contact respiration monitoring. In this paper, we verified the effectiveness of the system, and proposed screening method of the sleep disordered breathing. It was shown that our system could equivalently measure the respiration with thermistor and accelerograph. And, the respiratory condition of sleepers can be grasped by our screening method in one look, and it seems to be useful for the support of the screening of sleep disordered breathing.

Real-time and online screening method for materials emitting volatile organic compounds

NASA Astrophysics Data System (ADS)

Kim, Changhyuk; Sul, Yong Tae; Pui, David Y. H.

2016-09-01

In the semiconductor industry, volatile organic compounds (VOCs) in the cleanroom air work as airborne molecular contamination, which reduce the production yield of semiconductor chips by forming nanoparticles and haze on silicon wafers and photomasks under ultraviolet irradiation during photolithography processes. Even though VOCs in outdoor air are removed by gas filters, VOCs can be emitted from many kinds of materials used in cleanrooms, such as organic solvents and construction materials (e.g., adhesives, flame retardants and sealants), threatening the production of semiconductors. Therefore, finding new replacements that emit lower VOCs is now essential in the semiconductor industry. In this study, we developed a real-time and online method to screen materials for developing the replacements by converting VOCs into nanoparticles under soft X-ray irradiation. This screening method was applied to measure VOCs emitted from different kinds of organic solvents and adhesives. Our results showed good repeatability and high sensitivity for VOCs, which come from aromatic compounds, some alcohols and all tested adhesives (Super glue and cleanroom-use adhesives). In addition, the overall trend of measured VOCs from cleanroom-use adhesives was well matched with those measured by a commercial thermal desorption-gas chromatography-mass spectrometry, which is a widely used off-line method for analyzing VOCs. Based on the results, this screening method can help accelerate the developing process for reducing VOCs in cleanrooms.

A novel accelerated oxidative stability screening method for pharmaceutical solids.

PubMed

Zhu, Donghua Alan; Zhang, Geoff G Z; George, Karen L S T; Zhou, Deliang

2011-08-01

Despite the fact that oxidation is the second most frequent degradation pathway for pharmaceuticals, means of evaluating the oxidative stability of pharmaceutical solids, especially effective stress testing, are still lacking. This paper describes a novel experimental method for peroxide-mediated oxidative stress testing on pharmaceutical solids. The method utilizes urea-hydrogen peroxide, a molecular complex that undergoes solid-state decomposition and releases hydrogen peroxide vapor at elevated temperatures (e.g., 30°C), as a source of peroxide. The experimental setting for this method is simple, convenient, and can be operated routinely in most laboratories. The fundamental parameter of the system, that is, hydrogen peroxide vapor pressure, was determined using a modified spectrophotometric method. The feasibility and utility of the proposed method in solid form selection have been demonstrated using various solid forms of ephedrine. No degradation was detected for ephedrine hydrochloride after exposure to the hydrogen peroxide vapor for 2 weeks, whereas both anhydrate and hemihydrate free base forms degraded rapidly under the test conditions. In addition, both the anhydrate and the hemihydrate free base degraded faster when exposed to hydrogen peroxide vapor at 30°C under dry condition than at 30°C/75% relative humidity (RH). A new degradation product was also observed under the drier condition. The proposed method provides more relevant screening conditions for solid dosage forms, and is useful in selecting optimal solid form(s), determining potential degradation products, and formulation screening during development. Copyright © 2011 Wiley-Liss, Inc.

New screening methods for donor eye-bank eyes.

PubMed

Terry, M A; Ousley, P J

1999-07-01

Current methods of screening donor eyes for corneal transplantation are not always effective in excluding corneas with abnormal topography. We used the Orbscan to determine whether corneal-thickness maps could be used as a technique for donor tissue screening. Forty eye-bank eyes were measured with the Orbscan, and a corneal-thickness map was generated. Average central pachymetry measurements from each map were compared with the thinnest midperipheral thickness reading. Two eyes from a donor who had photorefractive keratectomy (PRK) and two eyes from a donor with keratoconus were then compared with the normal donor eye results. The average difference between the thinnest midperipheral pachymetry and the central pachymetry in the control group was 0.040 +/- 0.026 mm. The eyes from the donor with PRK showed larger disparities between the central and midperipheral thicknesses because of the thinned central cornea, with differences of 0.154 mm in the right eye and 0.106 mm in the left eye. The eyes from the donor with keratoconus had midperipheral corneas that were thinner than the center, indicating eccentric, ectatic cones. The differences in thickness between the center and midperiphery in the eyes from the donor with PRK and the donor with keratoconus differed from the control group by >2 SD. Diseases or surgery that affect the relationship between the central and midperipheral corneal thickness may be screened through Orbscan pachymetry mapping with comparison with a normal range.

Using the Screened Coulomb Potential to Illustrate the Variational Method

ERIC Educational Resources Information Center

Zuniga, Jose; Bastida, Adolfo; Requena, Alberto

2012-01-01

The screened Coulomb potential, or Yukawa potential, is used to illustrate the application of the single and linear variational methods. The trial variational functions are expressed in terms of Slater-type functions, for which the integrals needed to carry out the variational calculations are easily evaluated in closed form. The variational…

Condorcet and borda count fusion method for ligand-based virtual screening.

PubMed

Ahmed, Ali; Saeed, Faisal; Salim, Naomie; Abdo, Ammar

2014-01-01

It is known that any individual similarity measure will not always give the best recall of active molecule structure for all types of activity classes. Recently, the effectiveness of ligand-based virtual screening approaches can be enhanced by using data fusion. Data fusion can be implemented using two different approaches: group fusion and similarity fusion. Similarity fusion involves searching using multiple similarity measures. The similarity scores, or ranking, for each similarity measure are combined to obtain the final ranking of the compounds in the database. The Condorcet fusion method was examined. This approach combines the outputs of similarity searches from eleven association and distance similarity coefficients, and then the winner measure for each class of molecules, based on Condorcet fusion, was chosen to be the best method of searching. The recall of retrieved active molecules at top 5% and significant test are used to evaluate our proposed method. The MDL drug data report (MDDR), maximum unbiased validation (MUV) and Directory of Useful Decoys (DUD) data sets were used for experiments and were represented by 2D fingerprints. Simulated virtual screening experiments with the standard two data sets show that the use of Condorcet fusion provides a very simple way of improving the ligand-based virtual screening, especially when the active molecules being sought have a lowest degree of structural heterogeneity. However, the effectiveness of the Condorcet fusion was increased slightly when structural sets of high diversity activities were being sought.

Condorcet and borda count fusion method for ligand-based virtual screening

PubMed Central

2014-01-01

Background It is known that any individual similarity measure will not always give the best recall of active molecule structure for all types of activity classes. Recently, the effectiveness of ligand-based virtual screening approaches can be enhanced by using data fusion. Data fusion can be implemented using two different approaches: group fusion and similarity fusion. Similarity fusion involves searching using multiple similarity measures. The similarity scores, or ranking, for each similarity measure are combined to obtain the final ranking of the compounds in the database. Results The Condorcet fusion method was examined. This approach combines the outputs of similarity searches from eleven association and distance similarity coefficients, and then the winner measure for each class of molecules, based on Condorcet fusion, was chosen to be the best method of searching. The recall of retrieved active molecules at top 5% and significant test are used to evaluate our proposed method. The MDL drug data report (MDDR), maximum unbiased validation (MUV) and Directory of Useful Decoys (DUD) data sets were used for experiments and were represented by 2D fingerprints. Conclusions Simulated virtual screening experiments with the standard two data sets show that the use of Condorcet fusion provides a very simple way of improving the ligand-based virtual screening, especially when the active molecules being sought have a lowest degree of structural heterogeneity. However, the effectiveness of the Condorcet fusion was increased slightly when structural sets of high diversity activities were being sought. PMID:24883114

Pharmacy diabetes care program: analysis of two screening methods for undiagnosed type 2 diabetes in Australian community pharmacy.

PubMed

Krass, I; Mitchell, B; Clarke, P; Brillant, M; Dienaar, R; Hughes, J; Lau, P; Peterson, G; Stewart, K; Taylor, S; Wilkinson, J; Armour, C

2007-03-01

To compare the efficacy and cost-effectiveness of two methods of screening for undiagnosed type 2 diabetes in Australian community pharmacy. A random sample of 30 pharmacies were allocated into two groups: (i) tick test only (TTO); or (ii) sequential screening (SS) method. Both methods used the same initial risk assessment for type 2 diabetes. Subjects with one or more risk factors in the TTO group were offered a referral to their general practitioner (GP). Under the SS method, patients with risk factors were offered a capillary blood glucose test and those identified as being at risk referred to a GP. The effectiveness and cost-effectiveness of these approaches was assessed. A total of 1286 people were screened over a period of 3 months. The rate of diagnosis of diabetes was significantly higher for SS compared with the TTO method (1.7% versus 0.2%; p=0.008). The SS method resulted in fewer referrals to the GP and a higher uptake of referrals than the TTO method and so was the more cost-effective screening method. SS is the superior method from a cost and efficacy perspective. It should be considered as the preferred option for screening by community based pharmacists in Australia.

Electrochemical estrogen screen method based on the electrochemical behavior of MCF-7 cells.

PubMed

Li, Jinlian; Song, Jia; Bi, Sheng; Zhou, Shi; Cui, Jiwen; Liu, Jiguang; Wu, Dongmei

2016-08-05

It was an urgent task to develop quick, cheap and accurate estrogen screen method for evaluating the estrogen effect of the booming chemicals. In this study, the voltammetric behavior between the estrogen-free and normal fragmented MCF-7 cell suspensions were compared, and the electrochemical signal (about 0.68V attributed by xanthine and guanine) of the estrogen-free fragmented MCF-7 cell suspension was obviously lower than that of the normal one. The electrochemistry detection of ex-secretion purines showed that the ability of ex-secretion purines of cells sharp decreased due to the removing of endogenous estrogen. The results indicated that the electrochemical signal of MCF-7 cells was related to the level of intracellular estrogen. When the level of intracellular estrogen was down-regulated, the concentrations of the xanthine and hypoxanthine decreased, which led to the electrochemical signal of MCF-7 cells fall. Based on the electrochemical signal, the electrochemical estrogen screen method was established. The estrogen effect of estradiol, nonylphenol and bisphenol A was evaluated with the electrochemical method, and the result was accordant with that of MTT assay. The electrochemical estrogen screen method was simple, quickly, cheap, objective, and it exploits a new way for the evaluation of estrogenic effects of chemicals. Copyright © 2016. Published by Elsevier B.V.

A Rapid and Efficient Screening Method for Antibacterial Compound-Producing Bacteria.

PubMed

Hettiarachchi, Sachithra; Lee, Su-Jin; Lee, Youngdeuk; Kwon, Young-Kyung; De Zoysa, Mahanama; Moon, Song; Jo, Eunyoung; Kim, Taeho; Kang, Do-Hyung; Heo, Soo-Jin; Oh, Chulhong

2017-08-28

Antibacterial compounds are widely used in the treatment of human and animal diseases. The overuse of antibiotics has led to a rapid rise in the prevalence of drug-resistant bacteria, making the development of new antibacterial compounds essential. This study focused on developing a fast and easy method for identifying marine bacteria that produce antibiotic compounds. Eight randomly selected marine target bacterial species ( Agrococcus terreus, Bacillus algicola, Mesoflavibacter zeaxanthinifaciens, Pseudoalteromonas flavipulchra, P. peptidolytica, P. piscicida, P. rubra , and Zunongwangia atlantica ) were tested for production of antibacterial compounds against four strains of test bacteria ( B. cereus, B. subtilis, Halomonas smyrnensis , and Vibrio alginolyticus ). Colony picking was used as the primary screening method. Clear zones were observed around colonies of P. flavipulchra, P. peptidolytica, P. piscicida , and P. rubra tested against B. cereus, B. subtilis , and H. smyrnensis . The efficiency of colony scraping and broth culture methods for antimicrobial compound extraction was also compared using a disk diffusion assay. P. peptidolytica, P. piscicida , and P. rubra showed antagonistic activity against H. smyrnensis, B. cereus , and B. subtilis , respectively, only in the colony scraping method. Our results show that colony picking and colony scraping are effective, quick, and easy methods of screening for antibacterial compound-producing bacteria.

Constraint factor graph cut-based active contour method for automated cellular image segmentation in RNAi screening.

PubMed

Chen, C; Li, H; Zhou, X; Wong, S T C

2008-05-01

Image-based, high throughput genome-wide RNA interference (RNAi) experiments are increasingly carried out to facilitate the understanding of gene functions in intricate biological processes. Automated screening of such experiments generates a large number of images with great variations in image quality, which makes manual analysis unreasonably time-consuming. Therefore, effective techniques for automatic image analysis are urgently needed, in which segmentation is one of the most important steps. This paper proposes a fully automatic method for cells segmentation in genome-wide RNAi screening images. The method consists of two steps: nuclei and cytoplasm segmentation. Nuclei are extracted and labelled to initialize cytoplasm segmentation. Since the quality of RNAi image is rather poor, a novel scale-adaptive steerable filter is designed to enhance the image in order to extract long and thin protrusions on the spiky cells. Then, constraint factor GCBAC method and morphological algorithms are combined to be an integrated method to segment tight clustered cells. Compared with the results obtained by using seeded watershed and the ground truth, that is, manual labelling results by experts in RNAi screening data, our method achieves higher accuracy. Compared with active contour methods, our method consumes much less time. The positive results indicate that the proposed method can be applied in automatic image analysis of multi-channel image screening data.

DEMONSTRATION BULLETIN: FIELD ANALYTICAL SCREENING PROGRAM: PCB METHOD - U.S. ENVIRONMENTAL PROTECTION AGENCY

EPA Science Inventory

The field analytical screening program (FASP) polychlorinated biphenyl (PCB) method uses a temperature-programmable gas chromatograph (GC) equipped with an electron capture detector (ECD) to identify and quantify PCBs. Gas chromatography is an EPA-approved method for determi...

Method for in vitro screening of aquatic fungicides

USGS Publications Warehouse

Bailey, T.A.

1983-01-01

Methods were developed for in vitro screening of candidate aquatic fungicides for efficacy against Achlya fiagellata, A. racemosa, Saprolegnia hypogyna and S. megasperma. Agar plugs containing fungal hyphae, removed from the edge of actively growing colonies, were placed in the depressions of spot plates containing 1a??0, 10a??0 and 100 mg/I of the candidate compounds for 15 or 60 min. After exposure, the plugs were transferred on to filter papers (0a??45-A?m pore) in a holder, rinsed, and then placed on cornmeal agar medium in tri-petri dishes. The plates were checked for mycelial growth after 48, 96 and 168 h of incubation in a lighted (400-800 A?m) environmental control chamber at 20A?2A?C. Criteria for the acceptance or rejection of candidate aquatic fungicides for further study were based on the antifungal spectrum index (ASI) comparisons between respective compounds and malachite green after 48 h and the concentration level producing complete growth inhibition. Candidate compounds whose ASI was less than 50% that of malachite green after 48 h or did not inhibit growth at levels less than 100 mg/l were rejected. This method provides a base from which in vivo and definitive test regimens can be developed. Preliminary in vitro screening of candidate fungicides reduces the need for costly in vivo tests on compounds that have low antifungal activity.

Barrier screens: a method to sample blood-fed and host-seeking exophilic mosquitoes

PubMed Central

2013-01-01

Background Determining the proportion of blood meals on humans by outdoor-feeding and resting mosquitoes is challenging. This is largely due to the difficulty of finding an adequate and unbiased sample of resting, engorged mosquitoes to enable the identification of host blood meal sources. This is particularly difficult in the south-west Pacific countries of Indonesia, the Solomon Islands and Papua New Guinea where thick vegetation constitutes the primary resting sites for the exophilic mosquitoes that are the primary malaria and filariasis vectors. Methods Barrier screens of shade-cloth netting attached to bamboo poles were constructed between villages and likely areas where mosquitoes might seek blood meals or rest. Flying mosquitoes, obstructed by the barrier screens, would temporarily stop and could then be captured by aspiration at hourly intervals throughout the night. Results In the three countries where this method was evaluated, blood-fed females of Anopheles farauti, Anopheles bancroftii, Anopheles longirostris, Anopheles sundaicus, Anopheles vagus, Anopheles kochi, Anopheles annularis, Anopheles tessellatus, Culex vishnui, Culex quinquefasciatus and Mansonia spp were collected while resting on the barrier screens. In addition, female Anopheles punctulatus and Armigeres spp as well as male An. farauti, Cx. vishnui, Cx. quinquefasciatus and Aedes species were similarly captured. Conclusions Building barrier screens as temporary resting sites in areas where mosquitoes were likely to fly was an extremely time-effective method for collecting an unbiased representative sample of engorged mosquitoes for determining the human blood index. PMID:23379959

Knowledge-Based Methods To Train and Optimize Virtual Screening Ensembles

PubMed Central

2016-01-01

Ensemble docking can be a successful virtual screening technique that addresses the innate conformational heterogeneity of macromolecular drug targets. Yet, lacking a method to identify a subset of conformational states that effectively segregates active and inactive small molecules, ensemble docking may result in the recommendation of a large number of false positives. Here, three knowledge-based methods that construct structural ensembles for virtual screening are presented. Each method selects ensembles by optimizing an objective function calculated using the receiver operating characteristic (ROC) curve: either the area under the ROC curve (AUC) or a ROC enrichment factor (EF). As the number of receptor conformations, N, becomes large, the methods differ in their asymptotic scaling. Given a set of small molecules with known activities and a collection of target conformations, the most resource intense method is guaranteed to find the optimal ensemble but scales as O(2N). A recursive approximation to the optimal solution scales as O(N2), and a more severe approximation leads to a faster method that scales linearly, O(N). The techniques are generally applicable to any system, and we demonstrate their effectiveness on the androgen nuclear hormone receptor (AR), cyclin-dependent kinase 2 (CDK2), and the peroxisome proliferator-activated receptor δ (PPAR-δ) drug targets. Conformations that consisted of a crystal structure and molecular dynamics simulation cluster centroids were used to form AR and CDK2 ensembles. Multiple available crystal structures were used to form PPAR-δ ensembles. For each target, we show that the three methods perform similarly to one another on both the training and test sets. PMID:27097522

Screening methods for assessment of biodegradability of chemicals in seawater--results from a ring test

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nyholm, N.; Kristensen, P.

1992-04-01

An international ring test involving 14 laboratories was organized on behalf of the Commission of the European Economic Communities (EEC) with the purpose of evaluating two proposed screening methods for assessment of biodegradability in seawater: (a) a shake flask die-away test based primarily on analysis of dissolved organic carbon and (b) a closed bottle test based on determination of dissolved oxygen. Both tests are performed with nutrient-enriched natural seawater as the test medium and with no inoculum added other than the natural seawater microflora. The test methods are seawater versions of the modified OECD screening test and the closed bottlemore » test, respectively, adopted by the Organization for Economic Cooperation and Development (OECD) and by the EEC as tests for ready biodegradability.' The following five chemicals were examined: sodium benzoate, aniline, diethylene glycol, pentaerythritol, and 4-nitrophenol. Sodium benzoate and aniline, which are known to be generally readily biodegradable consistently degraded in practically all tests, thus demonstrating the technical feasibility of the methods. Like in previous ring tests with freshwater screening methods variable results were obtained with the other three compounds, which is believed primarily to be due to site-specific differences between the microflora of the different seawater samples used and to some extent also to differences in the applied concentrations of test material. A positive result with the screening methods indicates that the test substance will most likely degrade relatively rapidly in seawater from the site of collection, while a negative test result does not preclude biodegradability under environmental conditions where the concentrations of chemicals are much lower than the concentrations applied for analytical reasons in screening tests.« less

Different Routes for Conifer- and Sinapaldehyde and Higher Saccharification upon Deficiency in the Dehydrogenase CAD11[OPEN

PubMed Central

Laurans, Françoise; Foster, Cliff; Légée, Frédéric

2017-01-01

In the search for renewable energy sources, genetic engineering is a promising strategy to improve plant cell wall composition for biofuel and bioproducts generation. Lignin is a major factor determining saccharification efficiency and, therefore, is a prime target to engineer. Here, lignin content and composition were modified in poplar (Populus tremula × Populus alba) by specifically down-regulating CINNAMYL ALCOHOL DEHYDROGENASE1 (CAD1) by a hairpin-RNA-mediated silencing approach, which resulted in only 5% residual CAD1 transcript abundance. These transgenic lines showed no biomass penalty despite a 10% reduction in Klason lignin content and severe shifts in lignin composition. Nuclear magnetic resonance spectroscopy and thioacidolysis revealed a strong increase (up to 20-fold) in sinapaldehyde incorporation into lignin, whereas coniferaldehyde was not increased markedly. Accordingly, ultra-high-performance liquid chromatography-mass spectrometry-based phenolic profiling revealed a more than 24,000-fold accumulation of a newly identified compound made from 8-8 coupling of two sinapaldehyde radicals. However, no additional cinnamaldehyde coupling products could be detected in the CAD1-deficient poplars. Instead, the transgenic lines accumulated a range of hydroxycinnamate-derived metabolites, of which the most prominent accumulation (over 8,500-fold) was observed for a compound that was identified by purification and nuclear magnetic resonance as syringyl lactic acid hexoside. Our data suggest that, upon down-regulation of CAD1, coniferaldehyde is converted into ferulic acid and derivatives, whereas sinapaldehyde is either oxidatively coupled into S′(8-8)S′ and lignin or converted to sinapic acid and derivatives. The most prominent sink of the increased flux to hydroxycinnamates is syringyl lactic acid hexoside. Furthermore, low-extent saccharification assays, under different pretreatment conditions, showed strongly increased glucose (up to +81%) and xylose

Ethanol production from ensiled rice straw and whole-crop silage by the simultaneous enzymatic saccharification and fermentation process.

PubMed

Shinozaki, Yukiko; Kitamoto, Hiroko K

2011-03-01

Silage production from rice straw and whole-plant forage paddy rice is increasing in Japan because of decrease in rice consumption. One potential use for this silage is bioethanol production. In this study, we analyzed the effectiveness of three different commercially available cellulases at saccharification of sun-dried rice straw, ensiled rice straw, and rice whole-crop silage (WCS). Furthermore, the ethanol productivity of the simultaneous saccharification and ethanol fermentation process (SSF) from the same plant substrates was analyzed. Among the three kinds of cellulases tested (Novozymes NS50013, Genencor GC220, and Acremonium cellulase), Acremonium cellulase showed the highest ethanol production for the three plant substrates, and the WCS produced the highest ethanol level. Analysis of the enzymatic degradation activity of the cellulases revealed that Acremonium cellulase contained remarkably high glucoamylase and pectinase side activities relative to the other cellulase preparations. The addition of glucoamylase and pectinase to the other two cellulases significantly increased ethanol productivity to levels observed for the Acremonium cellulase preparation, which showed little enhanced performance with the addition of the same enzymes. Finally, we tested whether milling and sterilization had an effect on ethanol production and found that sterilized silage produced higher ethanol levels but that the milling process had no significant effect. These results show that (i) silage made from whole-plant rice can be used for bioethanol production and (ii) the proper selection and combination of commercially available enzymes can make SSF more cost efficient by removing the need for a pre-treatment step. Copyright © 2010 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Structural and optical characterization of NiSe film grown by screen-printing method

NASA Astrophysics Data System (ADS)

Sharma, Kapil; Sharma, D. K.; Dwivedi, D. K.; Kumar, Vipin

2018-05-01

In present investigation NiSe films were grown by economical screen-printing method. Optimum conditions for growing good quality screen-printed films were found. The films were characterized for their structural and optical properties. The polycrystalline nature of films with hexagonal structure was confirmed through XRD analysis. Direct type of optical band gap of 1.75 eV for the NiSe film was confirmed by optical characterization.

Simultaneous saccharification and fermentation of fungal pretreated cornstalk for hydrogen production using Thermoanaerobacterium thermosaccharolyticum W16.

PubMed

Zhao, Lei; Cao, Guang-Li; Wang, Ai-Jie; Guo, Wan-Qian; Ren, Hong-Yu; Ren, Nan-Qi

2013-10-01

In this research, environmentally friendly fungal pretreatment was first adopted for deconstruction of cornstalk. Then the fungal-pretreated cornstalk was employed to produce hydrogen in simultaneous saccharification and fermentation (SSF) using crude enzyme from Trichoderma viride and Thermoanaerobacterium thermosaccharolyticum W16. The influence of various factors including substrate concentration, initial pH, and enzyme loading on hydrogen production were evaluated. The highest hydrogen yield of 89.3 ml/g-cornstalk was obtained with an initial pH 6.5, 0.75% substrate concentration, and 34 FPU/g cellulose. Compared the result with SSF of physical or chemical pretreated lignocellulosic materials, this research suggested an economic and efficient way for hydrogen production from lignocellulosic biomass. Copyright © 2013 Elsevier Ltd. All rights reserved.

Two-stage acid saccharification of fractionated Gelidium amansii minimizing the sugar decomposition.

PubMed

Jeong, Tae Su; Kim, Young Soo; Oh, Kyeong Keun

2011-11-01

Two-stage acid hydrolysis was conducted on easy reacting cellulose and resistant reacting cellulose of fractionated Gelidium amansii (f-GA). Acid hydrolysis of f-GA was performed at between 170 and 200 °C for a period of 0-5 min, and an acid concentration of 2-5% (w/v, H2SO4) to determine the optimal conditions for acid hydrolysis. In the first stage of the acid hydrolysis, an optimum glucose yield of 33.7% was obtained at a reaction temperature of 190 °C, an acid concentration of 3.0%, and a reaction time of 3 min. In the second stage, a glucose yield of 34.2%, on the basis the amount of residual cellulose from the f-GA, was obtained at a temperature of 190 °C, a sulfuric acid concentration of 4.0%, and a reaction time 3.7 min. Finally, 68.58% of the cellulose derived from f-GA was converted into glucose through two-stage acid saccharification under aforementioned conditions. Copyright © 2011 Elsevier Ltd. All rights reserved.

Saccharification of citrus wastes by immobilized polygalacturonase in an improved alginate matrix.

PubMed

Ramírez-Tapias, Yuly A; Lapasset Laumann, Aldana S; Britos, Claudia N; Rivero, Cintia W; Trelles, Jorge A

2017-12-01

Enzyme immobilization using hydrogels is a low-cost and effective system for the degradation of bulk pectin derived from orange industry residues. Polygalacturonases obtained from four different bacterial strains of Streptomyces genus were immobilized in alginate gel and assayed for pectin hydrolysis. The enzyme from Streptomyces halstedii ATCC 10897 proved to be superior and more stable within the alginate matrix. Furthermore, a new strategy to improve alginate bead stability using a mixture of calcium and strontium is reported; this technique allowed enhancing the mechanical properties by combining different amounts of these cations for ionotropic gelation. The developed biocatalyst showed maximum hydrolysis at 2 h, generating 1.54 mg/mL of reducing sugars and decreasing the viscosity of polygalacturonic acid by 98.9%. Reusability up to 29 successive reactions (58 h) demonstrated a very stable performance. The heterogeneous biocatalyst was used in the enzymatic saccharification of orange peel albedo (2.23 mg/mL) for adding value to this agro-waste by industrial exploitation.

Periodic peristalsis increasing acetone-butanol-ethanol productivity during simultaneous saccharification and fermentation of steam-exploded corn straw.

PubMed

Li, Jingwen; Wang, Lan; Chen, Hongzhang

2016-11-01

The acetone-butanol-ethanol (ABE) fermentation of lignocellulose at high solids content has recently attracted extensive attention. However, the productivity of high solids ABE fermentation of lignocellulose is typically low in traditional processes due to the lack of efficient intensifying methods. In the present study, periodic peristalsis, a novel intensifying method, was applied to improve ABE production by the simultaneous saccharification and fermentation (SSF) of steam-exploded corn straw using Clostridium acetobutylicum ATCC824. The ABE concentration and the ABE productivity of SSF at a solids content of 17.5% (w/w) with periodic peristalsis were 17.1 g/L and 0.20 g/(L h), respectively, which were higher than those obtained under static conditions (15.2 g/L and 0.14 g/(L h)). The initial sugar conversion rate over the first 12 h with periodic peristalsis was 4.67 g/(L h) at 10 FPU/g cellulase dosage and 15% (w/w) solids content, an increase of 49.7% compared with the static conditions. With periodic peristalsis, the period of batch fermentation was shortened from 108 h to 84 h. The optimal operating regime was a low frequency (6 h -1 ) of periodic peristalsis in the acid-production phase (0-48 h) of SSF. Therefore, periodic peristalsis should be an effective intensifying method to increase the productivity of ABE fermentation at high solids content. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

A choice-based screening method for compulsive drug users in rats.

PubMed

Lenoir, Magalie; Augier, Eric; Vouillac, Caroline; Ahmed, Serge H

2013-07-01

We describe a protocol for screening compulsive drug users among cocaine self-administering rats, the most frequently used animal model in addiction research. Rats are first trained on several alternating days to self-administer either cocaine (i.v.) or saccharin-sweetened water (by mouth)--a potent, albeit nonessential, nondrug reward. Then rats are allowed to choose between the two rewards over several days until the preference stabilizes. Most rats choose to stop using cocaine and pursue the alternative reward. Only a minority of Wistar strain rats (generally 15%) persist in taking the drug, regardless of the severity of past cocaine use and even when made hungry and offered the possibility to relieve their physiological need. Persistence of cocaine use in the face of a high-stakes choice is a core defining feature of compulsion. This choice-based screening method for compulsive drug users is easy to implement, has several important applications, and compares well with other methods in the field. 2013 by John Wiley & Sons, Inc.

Isotonic Regression Based-Method in Quantitative High-Throughput Screenings for Genotoxicity

PubMed Central

Fujii, Yosuke; Narita, Takeo; Tice, Raymond Richard; Takeda, Shunich

2015-01-01

Quantitative high-throughput screenings (qHTSs) for genotoxicity are conducted as part of comprehensive toxicology screening projects. The most widely used method is to compare the dose-response data of a wild-type and DNA repair gene knockout mutants, using model-fitting to the Hill equation (HE). However, this method performs poorly when the observed viability does not fit the equation well, as frequently happens in qHTS. More capable methods must be developed for qHTS where large data variations are unavoidable. In this study, we applied an isotonic regression (IR) method and compared its performance with HE under multiple data conditions. When dose-response data were suitable to draw HE curves with upper and lower asymptotes and experimental random errors were small, HE was better than IR, but when random errors were big, there was no difference between HE and IR. However, when the drawn curves did not have two asymptotes, IR showed better performance (p < 0.05, exact paired Wilcoxon test) with higher specificity (65% in HE vs. 96% in IR). In summary, IR performed similarly to HE when dose-response data were optimal, whereas IR clearly performed better in suboptimal conditions. These findings indicate that IR would be useful in qHTS for comparing dose-response data. PMID:26673567

Modeling and parameter identification of the simultaneous saccharification-fermentation process for ethanol production.

PubMed

Ochoa, Silvia; Yoo, Ahrim; Repke, Jens-Uwe; Wozny, Günter; Yang, Dae Ryook

2007-01-01

Despite many environmental advantages of using alcohol as a fuel, there are still serious questions about its economical feasibility when compared with oil-based fuels. The bioethanol industry needs to be more competitive, and therefore, all stages of its production process must be simple, inexpensive, efficient, and "easy" to control. In recent years, there have been significant improvements in process design, such as in the purification technologies for ethanol dehydration (molecular sieves, pressure swing adsorption, pervaporation, etc.) and in genetic modifications of microbial strains. However, a lot of research effort is still required in optimization and control, where the first step is the development of suitable models of the process, which can be used as a simulated plant, as a soft sensor or as part of the control algorithm. Thus, toward developing good, reliable, and simple but highly predictive models that can be used in the future for optimization and process control applications, in this paper an unstructured and a cybernetic model are proposed and compared for the simultaneous saccharification-fermentation process (SSF) for the production of ethanol from starch by a recombinant Saccharomyces cerevisiae strain. The cybernetic model proposed is a new one that considers the degradation of starch not only into glucose but also into dextrins (reducing sugars) and takes into account the intracellular reactions occurring inside the cells, giving a more detailed description of the process. Furthermore, an identification procedure based on the Metropolis Monte Carlo optimization method coupled with a sensitivity analysis is proposed for the identification of the model's parameters, employing experimental data reported in the literature.

A novel tandem mass spectrometry method for first-line screening of mainly beta-thalassemia from dried blood spots.

PubMed

Yu, Chaowen; Huang, Shuodan; Wang, Ming; Zhang, Juan; Liu, Hao; Yuan, Zhaojian; Wang, Xingbin; He, Xiaoyan; Wang, Jie; Zou, Lin

2017-02-10

Traditional methods for thalassemia screening are time-consuming and easily affected by cell hemolysis or hemoglobin degradation in stored blood samples. Tandem mass spectrometry (MS/MS) proved to be an effective technology for sickle cell disorders (SCD) screening. Here, we developed a novel MS/MS method for β-thalassemia screening from dried blood spots (DBS). Stable isotopic-labeled peptides were used as internal standards for quantification and calculation of the α:β-globin ratios. We used the α:β-globin ratio cutoffs to differentiate between normal individuals and patients with thalassemia. About 781 patients and 300 normal individuals were analyzed. The α:β-globin ratios showed significant difference between normal and β-thalassemia patients (P<0.01), particularly when the disease was homozygous or double heterozygous with another α- or β-thalassemia mutation. In the parallel study, all cases screened for suspected thalassemia from six hundred DBS samples by using this MS/MS method were successfully confirmed by genotyping. The intra-assay and inter-assay CVs of the ratios ranged from 2.4% to 3.9% and 4.7% to 7.1%, and there was no significant sample carryover or matrix effect for this MS/MS method. Combined with SCD screening, this MS/MS method could be used as a first-line screening assay for both structural and expression abnormalities of human hemoglobin. Traditional methods for thalassemia screening were depending on the structural integrity of tetramers and could be affected by hemolysis and degradation of whole blood samples, especially when stored. We used proteospecific peptides produced by the tryptic digestion of each globin to evaluate the production ratio between α- and β-globin chains, which turned out to be quite stable even when stored for more than two months. Though most of the peptides were specific to α-globin or β-globin, we only chose four most informative peptides and its stable isotopic-labeled peptides as internal

Convenient, sensitive and high-throughput method for screening botanic origin.

PubMed

Yuan, Yuan; Jiang, Chao; Liu, Libing; Yu, Shulin; Cui, Zhanhu; Chen, Min; Lin, Shufang; Wang, Shu; Huang, Luqi

2014-06-23

In this work, a rapid (within 4-5 h), sensitive and visible new method for assessing botanic origin is developed by combining loop-mediated isothermal amplification with cationic conjugated polymers. The two Chinese medicinal materials (Jin-Yin-Hua and Shan-Yin-Hua) with similar morphology and chemical composition were clearly distinguished by gene SNP genotyping assays. The identification of plant species in Patented Chinese drugs containing Lonicera buds is successfully performed using this detection system. The method is also robust enough to be used in high-throughput screening. This new method is very helpful to identify herbal materials, and is beneficial for detecting safety and quality of botanic products.

Convenient, Sensitive and High-Throughput Method for Screening Botanic Origin

NASA Astrophysics Data System (ADS)

Yuan, Yuan; Jiang, Chao; Liu, Libing; Yu, Shulin; Cui, Zhanhu; Chen, Min; Lin, Shufang; Wang, Shu; Huang, Luqi

2014-06-01

In this work, a rapid (within 4-5 h), sensitive and visible new method for assessing botanic origin is developed by combining loop-mediated isothermal amplification with cationic conjugated polymers. The two Chinese medicinal materials (Jin-Yin-Hua and Shan-Yin-Hua) with similar morphology and chemical composition were clearly distinguished by gene SNP genotyping assays. The identification of plant species in Patented Chinese drugs containing Lonicera buds is successfully performed using this detection system. The method is also robust enough to be used in high-throughput screening. This new method is very helpful to identify herbal materials, and is beneficial for detecting safety and quality of botanic products.

A new screening method for amphetamine and methamphetamine using dansyl chloride derivatization and cartridge fluorescence.

PubMed

Yamada, H; Ikeda-Wada, S; Oguri, K

1998-07-01

A new screening method for amphetamines was developed. It consists of derivatization with dansyl chloride, extraction of the derivative using a Sep-Pak C18 or a Bond Elut C18, solid phase extraction columns, and visualization of the fluorescence of the cartridge. A control test using drug-free urine showed no fluorescence. Amphetamine, methamphetamine and the methylenedioxy derivatives exhibited strong fluorescence, while related compounds, such as N-ethylamphetamine and fenetylline, were negative or weakly positive. The disadvantage of the present method is that it is a multi-step procedure and 20-30 min is required for screening. However, since it has a different specificity from the widely used immunochemical technique, it is suggested to be a useful screen for amphetamines.

A method to screen and evaluate tissue adhesives for joint repair applications

PubMed Central

2012-01-01

Background Tissue adhesives are useful means for various medical procedures. Since varying requirements cause that a single adhesive cannot meet all needs, bond strength testing remains one of the key applications used to screen for new products and study the influence of experimental variables. This study was conducted to develop an easy to use method to screen and evaluate tissue adhesives for tissue engineering applications. Method Tissue grips were designed to facilitate the reproducible production of substrate tissue and adhesive strength measurements in universal testing machines. Porcine femoral condyles were used to generate osteochondral test tissue cylinders (substrates) of different shapes. Viability of substrates was tested using PI/FDA staining. Self-bonding properties were determined to examine reusability of substrates (n = 3). Serial measurements (n = 5) in different operation modes (OM) were performed to analyze the bonding strength of tissue adhesives in bone (OM-1) and cartilage tissue either in isolation (OM-2) or under specific requirements in joint repair such as filling cartilage defects with clinical applied fibrin/PLGA-cell-transplants (OM-3) or tissues (OM-4). The efficiency of the method was determined on the basis of adhesive properties of fibrin glue for different assembly times (30 s, 60 s). Seven randomly generated collagen formulations were analyzed to examine the potential of method to identify new tissue adhesives. Results Viability analysis of test tissue cylinders revealed vital cells (>80%) in cartilage components even 48 h post preparation. Reuse (n = 10) of test substrate did not significantly change adhesive characteristics. Adhesive strength of fibrin varied in different test settings (OM-1: 7.1 kPa, OM-2: 2.6 kPa, OM-3: 32.7 kPa, OM-4: 30.1 kPa) and was increasing with assembly time on average (2.4-fold). The screening of the different collagen formulations revealed a substance with significant higher adhesive

Biomass pretreatment

DOEpatents

Hennessey, Susan Marie; Friend, Julie; Elander, Richard T; Tucker, III, Melvin P

2013-05-21

A method is provided for producing an improved pretreated biomass product for use in saccharification followed by fermentation to produce a target chemical that includes removal of saccharification and or fermentation inhibitors from the pretreated biomass product. Specifically, the pretreated biomass product derived from using the present method has fewer inhibitors of saccharification and/or fermentation without a loss in sugar content.

New Method of Screening Young Children for Defects in Visual Acuity*

PubMed Central

Withnell, Allan; Wilson, H. E.

1968-01-01

The methods used at present for screening young children's vision have disadvantages, such as that the child's intelligence can affect the result. In a new method three white cards are used; these are printed with one, two, or three black blocks arranged so that if a child can correctly state the number of blocks at 6 metres the visual acuity is at least 6/9. When tested on 186 children the new method gave better results than conventional tests; eight children with defective vision were picked up only by the new method and none were missed. PMID:5681052

New method of screening young children for defects in visual acuity.

PubMed

Withnell, A; Wilson, H E

1968-10-19

The methods used at present for screening young children's vision have disadvantages, such as that the child's intelligence can affect the result. In a new method three white cards are used; these are printed with one, two, or three black blocks arranged so that if a child can correctly state the number of blocks at 6 metres the visual acuity is at least 6/9. When tested on 186 children the new method gave better results than conventional tests; eight children with defective vision were picked up only by the new method and none were missed.

Allergic sensitization: screening methods

PubMed Central

2014-01-01

Experimental in silico, in vitro, and rodent models for screening and predicting protein sensitizing potential are discussed, including whether there is evidence of new sensitizations and allergies since the introduction of genetically modified crops in 1996, the importance of linear versus conformational epitopes, and protein families that become allergens. Some common challenges for predicting protein sensitization are addressed: (a) exposure routes; (b) frequency and dose of exposure; (c) dose-response relationships; (d) role of digestion, food processing, and the food matrix; (e) role of infection; (f) role of the gut microbiota; (g) influence of the structure and physicochemical properties of the protein; and (h) the genetic background and physiology of consumers. The consensus view is that sensitization screening models are not yet validated to definitively predict the de novo sensitizing potential of a novel protein. However, they would be extremely useful in the discovery and research phases of understanding the mechanisms of food allergy development, and may prove fruitful to provide information regarding potential allergenicity risk assessment of future products on a case by case basis. These data and findings were presented at a 2012 international symposium in Prague organized by the Protein Allergenicity Technical Committee of the International Life Sciences Institute’s Health and Environmental Sciences Institute. PMID:24739743

Different Routes for Conifer- and Sinapaldehyde and Higher Saccharification upon Deficiency in the Dehydrogenase CAD1.

PubMed

Van Acker, Rebecca; Déjardin, Annabelle; Desmet, Sandrien; Hoengenaert, Lennart; Vanholme, Ruben; Morreel, Kris; Laurans, Françoise; Kim, Hoon; Santoro, Nicholas; Foster, Cliff; Goeminne, Geert; Légée, Frédéric; Lapierre, Catherine; Pilate, Gilles; Ralph, John; Boerjan, Wout

2017-11-01

In the search for renewable energy sources, genetic engineering is a promising strategy to improve plant cell wall composition for biofuel and bioproducts generation. Lignin is a major factor determining saccharification efficiency and, therefore, is a prime target to engineer. Here, lignin content and composition were modified in poplar ( Populus tremula × Populus alba ) by specifically down-regulating CINNAMYL ALCOHOL DEHYDROGENASE1 ( CAD1 ) by a hairpin-RNA-mediated silencing approach, which resulted in only 5% residual CAD1 transcript abundance. These transgenic lines showed no biomass penalty despite a 10% reduction in Klason lignin content and severe shifts in lignin composition. Nuclear magnetic resonance spectroscopy and thioacidolysis revealed a strong increase (up to 20-fold) in sinapaldehyde incorporation into lignin, whereas coniferaldehyde was not increased markedly. Accordingly, ultra-high-performance liquid chromatography-mass spectrometry-based phenolic profiling revealed a more than 24,000-fold accumulation of a newly identified compound made from 8-8 coupling of two sinapaldehyde radicals. However, no additional cinnamaldehyde coupling products could be detected in the CAD1-deficient poplars. Instead, the transgenic lines accumulated a range of hydroxycinnamate-derived metabolites, of which the most prominent accumulation (over 8,500-fold) was observed for a compound that was identified by purification and nuclear magnetic resonance as syringyl lactic acid hexoside. Our data suggest that, upon down-regulation of CAD1 , coniferaldehyde is converted into ferulic acid and derivatives, whereas sinapaldehyde is either oxidatively coupled into S'(8-8)S' and lignin or converted to sinapic acid and derivatives. The most prominent sink of the increased flux to hydroxycinnamates is syringyl lactic acid hexoside. Furthermore, low-extent saccharification assays, under different pretreatment conditions, showed strongly increased glucose (up to +81%) and

A small-bolt method for screening tree protectants against bark beetles (coleoptera: curculionidae)

Treesearch

B.L. Strom; L.M. Roton

2009-01-01

A simple, small-bolt method was developed and refi ned for evaluating and screening treatments being considered as prophylactics against bark beetles (Coleoptera: Curculionidae: Scolytinae). Using this method, 4 insecticide products (3 active ingredients) were evaluated against the southern pine beetle, Dendroctonus frontalis Zimmermann, intermittently during a period...

Comparison of Adsorbed Mercury Screening Method With Cold-Vapor Atomic Absorption Spectrophotometry for Determination of Mercury in Soil

NASA Technical Reports Server (NTRS)

Easterling, Donald F.; Hovanitz, Edward S.; Street, Kenneth W.

2000-01-01

A field screening method for the determination of elemental mercury in environmental soil samples involves the thermal desorption of the mercury from the sample onto gold and then the thermal desorption from the gold to a gold-film mercury vapor analyzer. This field screening method contains a large number of conditions that could be optimized for the various types of soils encountered. In this study, the conditions were optimized for the determination of mercury in silty clay materials, and the results were comparable to the cold-vapor atomic absorption spectrophotometric method of determination. This paper discusses the benefits and disadvantages of employing the field screening method and provides the sequence of conditions that must be optimized to employ this method of determination on other soil types.

Biological pretreatment of rice straw with Streptomyces griseorubens JSD-1 and its optimized production of cellulase and xylanase for improved enzymatic saccharification efficiency.

PubMed

Zhang, Dan; Luo, Yanqing; Chu, Shaohua; Zhi, Yuee; Wang, Bin; Zhou, Pei

2016-08-17

Biological pretreatment of rice straw and production of reducing sugars by hydrolysis of bio-pretreated material with Streptomyces griseorubens JSD-1 was investigated. After 10 days of incubation, various chemical compositions of inoculated rice straw were degraded and used for further enzymatic hydrolysis studies. The production of cellulolytic enzyme by S. griseorubens JSD-1 favored the conversion of cellulose to reducing sugars. The culture medium for cellulolytic enzyme production by using agro-industrial wastes was optimized through response surface methodology. According to the response surface analysis, the concentrations of 11.13, 20.34, 4.61, and 2.85 g L(-1) for rice straw, wheat bran, peptone, and CaCO3, respectively, were found to be optimum for cellulase and xylanase production. Then the hydrolyzed spent Streptomyces cells were used as a nitrogen source and the maximum filter paper cellulase, carboxymethylcellulase, and xylanase activities of 25.79, 78.91, and 269.53 U mL(-1) were achieved. The crude cellulase produced by S. griseorubens JSD-1 was subsequently used for the hydrolysis of bio-pretreated rice straw, and the optimum saccharification efficiency of 88.13% was obtained, indicating that the crude enzyme might be used instead of commercial cellulase during a saccharification process. These results give a basis for further study of bioethanol production from agricultural cellulosic waste.

Overview of a workshop on screening methods for detecting potential (anti-) estrogenic/androgenic chemicals in wildlife

USGS Publications Warehouse

Ankley, Gerald T.; Mihaich, Ellen; Stahl, Ralph G.; Tillitt, Donald E.; Colborn, Theo; McMaster, Suzzanne; Miller, Ron; Bantle, John; Campbell, Pamela; Denslow, Nancy; Dickerson, Richard L.; Folmar, Leroy C.; Fry, Michael; Giesy, John P.; Gray, L. Earl; Guiney, Patrick; Hutchinson, Thomas; Kennedy, Sean W.; Kramer, Vincent; LeBlanc, Gerald A.; Mayes, Monte; Nimrod, Alison; Patino, Reynaldo; Peterson, Richard; Purdy, Richard; Ringer, Robert; Thomas, Peter C.; Touart, Les; Van Der Kraak, Glen; Zacharewski, Tim

1998-01-01

The U.S. Congress has passed legislation requiring the U.S. Environmental Protection Agency (U.S. EPA) to develop, validate, and implement screening tests for identifying potential endocrine-disrupting chemicals within 3 years. To aid in the identification of methods suitable for this purpose, the U.S. EPA, the Chemical Manufacturers Association, and the World Wildlife Fund sponsored several workshops, including the present one, which dealt with wildlife species. This workshop was convened with 30 international scientists representing multiple disciplines in March 1997 in Kansas City, Missouri, USA. Participants at the meeting identified methods in terms of their ability to indicate (anti-) estrogenic/androgenic effects, particularly in the context of developmental and reproductive processes. Data derived from structure-activity relationship models and in vitro test systems, although useful in certain contexts, cannot at present replace in vivo tests as the sole basis for screening. A consensus was reached that existing mammalian test methods (e.g., with rats or mice) generally are suitable as screens for assessing potential (anti-) estrogenic/ androgenic effects in mammalian wildlife. However, due to factors such as among-class variation in receptor structure and endocrine function, it is uncertain if these mammalian assays would be of broad utility as screens for other classes of vertebrate wildlife. Existing full and partial life-cycle tests with some avian and fish species could successfully identify chemicals causing endocrine disruption; however, these long-term tests are not suitable for routine screening. However, a number of short-term tests with species from these two classes exist that could serve as effective screening tools for chemicals inducing (anti-) estrogenic/androgenic effects. Existing methods suitable for identifying chemicals with these mechanisms of action in reptiles and amphibians are limited, but in the future, tests with species from

An EEG-based machine learning method to screen alcohol use disorder.

PubMed

Mumtaz, Wajid; Vuong, Pham Lam; Xia, Likun; Malik, Aamir Saeed; Rashid, Rusdi Bin Abd

2017-04-01

Screening alcohol use disorder (AUD) patients has been challenging due to the subjectivity involved in the process. Hence, robust and objective methods are needed to automate the screening of AUD patients. In this paper, a machine learning method is proposed that utilized resting-state electroencephalography (EEG)-derived features as input data to classify the AUD patients and healthy controls and to perform automatic screening of AUD patients. In this context, the EEG data were recorded during 5 min of eyes closed and 5 min of eyes open conditions. For this purpose, 30 AUD patients and 15 aged-matched healthy controls were recruited. After preprocessing the EEG data, EEG features such as inter-hemispheric coherences and spectral power for EEG delta, theta, alpha, beta and gamma bands were computed involving 19 scalp locations. The selection of most discriminant features was performed with a rank-based feature selection method assigning a weight value to each feature according to a criterion, i.e., receiver operating characteristics curve. For example, a feature with large weight was considered more relevant to the target labels than a feature with less weight. Therefore, a reduced set of most discriminant features was identified and further be utilized during classification of AUD patients and healthy controls. As results, the inter-hemispheric coherences between the brain regions were found significantly different between the study groups and provided high classification efficiency ( Accuracy  = 80.8, sensitivity  = 82.5, and specificity  = 80, F - Measure  = 0.78). In addition, the power computed in different EEG bands were found significant and provided an overall classification efficiency as ( Accuracy  = 86.6, sensitivity  = 95, specificity  = 82.5, and F - Measure  = 0.88). Further, the integration of these EEG feature resulted into even higher results ( Accuracy  = 89.3 %, sensitivity  = 88.5 %, specificity  = 91 %, and F

Nanoliter microfluidic hybrid method for simultaneous screening and optimization validated with crystallization of membrane proteins

PubMed Central

Li, Liang; Mustafi, Debarshi; Fu, Qiang; Tereshko, Valentina; Chen, Delai L.; Tice, Joshua D.; Ismagilov, Rustem F.

2006-01-01

High-throughput screening and optimization experiments are critical to a number of fields, including chemistry and structural and molecular biology. The separation of these two steps may introduce false negatives and a time delay between initial screening and subsequent optimization. Although a hybrid method combining both steps may address these problems, miniaturization is required to minimize sample consumption. This article reports a “hybrid” droplet-based microfluidic approach that combines the steps of screening and optimization into one simple experiment and uses nanoliter-sized plugs to minimize sample consumption. Many distinct reagents were sequentially introduced as ≈140-nl plugs into a microfluidic device and combined with a substrate and a diluting buffer. Tests were conducted in ≈10-nl plugs containing different concentrations of a reagent. Methods were developed to form plugs of controlled concentrations, index concentrations, and incubate thousands of plugs inexpensively and without evaporation. To validate the hybrid method and demonstrate its applicability to challenging problems, crystallization of model membrane proteins and handling of solutions of detergents and viscous precipitants were demonstrated. By using 10 μl of protein solution, ≈1,300 crystallization trials were set up within 20 min by one researcher. This method was compatible with growth, manipulation, and extraction of high-quality crystals of membrane proteins, demonstrated by obtaining high-resolution diffraction images and solving a crystal structure. This robust method requires inexpensive equipment and supplies, should be especially suitable for use in individual laboratories, and could find applications in a number of areas that require chemical, biochemical, and biological screening and optimization. PMID:17159147

Thin-Film Thermoelectric Module for Power Generator Applications Using a Screen-Printing Method

NASA Astrophysics Data System (ADS)

Lee, Heon-Bok; Yang, Hyun Jeong; We, Ju Hyung; Kim, Kukjoo; Choi, Kyung Cheol; Cho, Byung Jin

2011-05-01

A new process for fabricating a low-cost thermoelectric module using a screen-printing method has been developed. Thermoelectric properties of screen-printed ZnSb films were investigated in an effort to develop a thermoelectric module with low cost per watt. The screen-printed Zn x Sb1- x films showed a low carrier concentration and high Seebeck coefficient when x was in the range of 0.5 to 0.57 and the annealing temperature was kept below 550°C. When the annealing temperature was higher than 550°C, the carrier concentration of the Zn x Sb1- x films reached that of a metal, leading to a decrease of the Seebeck coefficient. In the present experiment, the optimized carrier concentration of screen-printed ZnSb was 7 × 1018/cm3. The output voltage and power density of the ZnSb film were 10 mV and 0.17 mW/cm2, respectively, at Δ T = 50 K. A thermoelectric module was produced using the proposed screen-printing approach with ZnSb and CoSb3 as p-type and n-type thermoelectric materials, respectively, and copper as the pad metal.

The effect of nonenzymatic protein on lignocellulose enzymatic hydrolysis and simultaneous saccharification and fermentation.

PubMed

Wang, Hui; Kobayashi, Shinichi; Hiraide, Hatsue; Cui, Zongjun; Mochidzuki, Kazuhiro

2015-01-01

Nonenzymatic protein was added to cellulase hydrolysis and simultaneous saccharification and fermentation (SSF) of different biomass materials. Adding bovine serum albumin (BSA) and corn steep before cellulase enhanced enzyme activity in solution and increased cellulose and xylose conversion rates. The cellulose conversion rate of filter paper hydrolysis was increased by 32.5 % with BSA treatment. When BSA was added before cellulase, the remaining activity in the solution was higher than that in a control without BSA pretreatment. During SSF with pretreated rice straw as the substrate, adding 1.0 mg/mL BSA increased the ethanol yield by 13.6 % and final xylose yield by 42.6 %. The results indicated that lignin interaction is not the only mechanism responsible for the positive BSA effect. BSA had a stabilizing effect on cellulase and relieved cumulative sugar inhibition of enzymatic hydrolysis of biomass materials. Thus, nonenzymatic protein addition represents a promising strategy in the biorefining of lignocellulose materials.

Non invasive diagnostic methods for better screening of peripheral arterial disease.

PubMed

Nirala, Neelamshobha; Periyasamy, R; Kumar, Awanish

2018-05-16

Peripheral arterial disease (PAD) is a common circulatory problem in which narrowed arteries reduce blood flow to extremities usually legs. It does not receive enough blood flow to keep up with demand. This causes symptoms, most notably leg pain while walking which is known as claudication. It is a common manifestation of type II Diabetes, but the relationship between other vascular diseases and lower limb (LL)-PAD has been poorly understood and investigated. When assessing a patient with clinically LLPAD, two questions are in order to establish a diagnosis: one is non-invasive testing and other is invasive. Invasive methods are painful and get so bad that some people need to have a leg surgery. People with Diabetes are at increased risk for amputation and it is used only when the damage is very severe. Diagnosis of LLPAD begins with a physical examination, patient history, certain questionnaire and non invasive mode of diagnosis is started for the screening of patients. Clinicians check for weak pulses in the legs and then decide for further diagnosis. Paper discusses the prevalence of LLPAD worldwide and in India along with the clinical effectiveness and limitations of these methods in case of Diabetes. The focus of this review is to discuss only those non invasive methods which are widely used for screening of LLPAD like Ankle brachial index (ABI), Toe brachial Index (TBI), and use of photoplethysmogram (PPG) specially in case of Diabetic patients. Also, this paper gives an overview of the work done using ABI, TBI, and PPG for detection of LLPAD. These tests are not painful and could be performed in a cost-effective manner to avoid delays in screening/diagnosis and also reduce costs. Copyright © 2018. Published by Elsevier Inc.

Enhanced simultaneous saccharification and fermentation of pretreated beech wood by in situ treatment with the white rot fungus Irpex lacteus in a membrane aerated biofilm reactor.

PubMed

Brethauer, Simone; Robert Lawrence, Shahab; Michael Hans-Peter, Studer

2017-08-01

The aim of the present study was to investigate the combination of steam pretreatment and biological treatment with lignin degrading fungal strains in order to enable efficient bioprocessing of beech wood to ethanol. In a sequential process of steam and fungal pretreatment followed by enzymatic hydrolysis, Irpex lacteus almost doubled the glucose yield for mildly pretreated beech wood, but could not improve yields for more severely pretreated substrates. However, when simultaneous saccharification and fermentation is combined with in situ I. lacteus treatment, which is enabled by the application of a membrane aerated biofilm reactor, ethanol yields of optimally steam pretreated beech could be improved from 65 to 80%. Generally, in situ fungal treatment during bioprocessing of lignocellulose is an interesting method to harness the versatile abilities of white rot fungi. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Who Gets the Job? First-Generation College Students' Perceptions of Employer Screening Methods

ERIC Educational Resources Information Center

Parks-Yancy, Rochelle; Cooley, Delonia

2018-01-01

What are first-generation college students' (FGCS) perspectives of employment screening methods? The authors investigate which methods FGCS believe are likely to cause an employer to extend a job offer and which methods yield the best pool of job applicants. Survey data were collected from undergraduate business majors. They were analyzed using…

Corn fiber, cobs and stover: enzyme-aided saccharification and co-fermentation after dilute acid pretreatment.

PubMed

Van Eylen, David; van Dongen, Femke; Kabel, Mirjam; de Bont, Jan

2011-05-01

Three corn feedstocks (fibers, cobs and stover) available for sustainable second generation bioethanol production were subjected to pretreatments with the aim of preventing formation of yeast-inhibiting sugar-degradation products. After pretreatment, monosaccharides, soluble oligosaccharides and residual sugars were quantified. The size of the soluble xylans was estimated by size exclusion chromatography. The pretreatments resulted in relatively low monosaccharide release, but conditions were reached to obtain most of the xylan-structures in the soluble part. A state of the art commercial enzyme preparation, Cellic CTec2, was tested in hydrolyzing these dilute acid-pretreated feedstocks. The xylose and glucose liberated were fermented by a recombinant Saccharomyces cerevisiae strain. In the simultaneous enzymatic saccharification and fermentation system employed, a concentration of more than 5% (v/v) (0.2g per g of dry matter) of ethanol was reached. Copyright © 2011 Elsevier Ltd. All rights reserved.

Parameter Estimation for Simultaneous Saccharification and Fermentation of Food Waste Into Ethanol Using Matlab Simulink

NASA Astrophysics Data System (ADS)

Davis, Rebecca Anne

The increase in waste disposal and energy costs has provided an incentive to convert carbohydrate-rich food waste streams into fuel. For example, dining halls and restaurants discard foods that require tipping fees for removal. An effective use of food waste may be the enzymatic hydrolysis of the waste to simple sugars and fermentation of the sugars to ethanol. As these wastes have complex compositions which may change day-to-day, experiments were carried out to test fermentability of two different types of food waste at 27° C using Saccharomyces cerevisiae yeast (ATCC4124) and Genencor's STARGEN™ enzyme in batch simultaneous saccharification and fermentation (SSF) experiments. A mathematical model of SSF based on experimentally matched rate equations for enzyme hydrolysis and yeast fermentation was developed in Matlab Simulink®. Using Simulink® parameter estimation 1.1.3, parameters for hydrolysis and fermentation were estimated through modified Michaelis-Menten and Monod-type equations with the aim of predicting changes in the levels of ethanol and glycerol from different initial concentrations of glucose, fructose, maltose, and starch. The model predictions and experimental observations agree reasonably well for the two food waste streams and a third validation dataset. The approach of using Simulink® as a dynamic visual model for SSF represents a simple method which can be applied to a variety of biological pathways and may be very useful for systems approaches in metabolic engineering in the future.

Robust high-throughput batch screening method in 384-well format with optical in-line resin quantification.

PubMed

Kittelmann, Jörg; Ottens, Marcel; Hubbuch, Jürgen

2015-04-15

High-throughput batch screening technologies have become an important tool in downstream process development. Although continuative miniaturization saves time and sample consumption, there is yet no screening process described in the 384-well microplate format. Several processes are established in the 96-well dimension to investigate protein-adsorbent interactions, utilizing between 6.8 and 50 μL resin per well. However, as sample consumption scales with resin volumes and throughput scales with experiments per microplate, they are limited in costs and saved time. In this work, a new method for in-well resin quantification by optical means, applicable in the 384-well format, and resin volumes as small as 0.1 μL is introduced. A HTS batch isotherm process is described, utilizing this new method in combination with optical sample volume quantification for screening of isotherm parameters in 384-well microplates. Results are qualified by confidence bounds determined by bootstrap analysis and a comprehensive Monte Carlo study of error propagation. This new approach opens the door to a variety of screening processes in the 384-well format on HTS stations, higher quality screening data and an increase in throughput. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of aging on lignin content, composition and enzymatic saccharification in Corymbia hybrids and parental taxa between years 9 and 12

DOE PAGES

Healey, Adam L.; Lupoi, Jason S.; Lee, David J.; ...

2016-07-02

Corymbia (a eucalypt) is an important forestry genus and a potential lignocellulosic bioenergy feedstock. The composition of the lignocellulosic cell wall significantly impacts pretreatment efficiency and conversion to biofuel but is variable and changes with age. In this study, we estimated Klason lignin content, composition, and monosaccharide (glucose and xylose) release after enzymatic saccharification of untreated and hydrothermally pretreated biomass from Corymbia parental species Corymbia torelliana (CT), Corymbia citriodora subsp. variegata (spotted gum; CCV), and interspecific F1 hybrids (CT x CCV) at ages 9 and 12 years from planting. Analysis of lignin composition derived from syringyl/guaiacyl monolignols (S/G) found significantmore » differences among taxa, with CT S/G ratios (2.2 and 2.0) being significantly lower than CCV (2.6 and 2.3) or hybrids (2.5 and 2.3) at ages 9 and 12 respectively. In general, enzymatic saccharification yields from untreated biomass were significantly different among taxa, with CT (113 and 75 mg g -1) and hybrids (108 and 81 mg g -1) yielding significantly higher glucose from untreated biomass than CCV (82 and 56 mg g -1) at ages 9 and 12 respectively. Comparison of traits within taxa between ages 9 and 12 found S/G ratios and glucose yields from untreated biomass were significantly lower in CT, CCV and hybrid taxa. As a result, the formation of lignocellulosic cell walls is complex, influenced by genetics and age of material, requiring optimization of rotation age for biofuel production and other industrial processes.« less

Modeling and experimental studies on intermittent starch feeding and citrate addition in simultaneous saccharification and fermentation of starch to flavor compounds.

PubMed

Chavan, Abhijit R; Raghunathan, Anuradha; Venkatesh, K V

2009-04-01

Simultaneous saccharification and fermentation (SSF) is a combined process of saccharification of a renewable bioresource and fermentation process to produce products, such as lactic acid and ethanol. Recently, SSF has been extensively used to convert various sources of cellulose and starch into fermentative products. Here, we present a study on production of buttery flavors, namely diacetyl and acetoin, by growing Lactobacillus rhamnosus on a starch medium containing the enzyme glucoamylase. We further develop a structured kinetics for the SSF process, which includes enzyme and growth kinetics. The model was used to simulate the effect of pH and temperature on the SSF process so as to obtain optimum operating conditions. The model was experimentally verified by conducting SSF using an initial starch concentration of 100 g/L. The study demonstrated that the developed kinetic was able to suggest strategies for improved productivities. The developed model was able to accurately predict the enhanced productivity of flavors in a three stage process with intermittent addition of starch. Experimental and simulations demonstrated that citrate addition can also lead to enhanced productivity of flavors. The developed optimal model for SSF was able to capture the dynamics of SSF in batch mode as well as in a three stage process. The structured kinetics was also able to quantify the effect of multiple substrates present in the medium. The study demonstrated that structured kinetic models can be used in the future for design and optimization of SSF as a batch or a fed-batch process.

Effect of aging on lignin content, composition and enzymatic saccharification in Corymbia hybrids and parental taxa between years 9 and 12

DOE Office of Scientific and Technical Information (OSTI.GOV)

Healey, Adam L.; Lupoi, Jason S.; Lee, David J.

Corymbia (a eucalypt) is an important forestry genus and a potential lignocellulosic bioenergy feedstock. The composition of the lignocellulosic cell wall significantly impacts pretreatment efficiency and conversion to biofuel but is variable and changes with age. In this study, we estimated Klason lignin content, composition, and monosaccharide (glucose and xylose) release after enzymatic saccharification of untreated and hydrothermally pretreated biomass from Corymbia parental species Corymbia torelliana (CT), Corymbia citriodora subsp. variegata (spotted gum; CCV), and interspecific F1 hybrids (CT x CCV) at ages 9 and 12 years from planting. Analysis of lignin composition derived from syringyl/guaiacyl monolignols (S/G) found significantmore » differences among taxa, with CT S/G ratios (2.2 and 2.0) being significantly lower than CCV (2.6 and 2.3) or hybrids (2.5 and 2.3) at ages 9 and 12 respectively. In general, enzymatic saccharification yields from untreated biomass were significantly different among taxa, with CT (113 and 75 mg g -1) and hybrids (108 and 81 mg g -1) yielding significantly higher glucose from untreated biomass than CCV (82 and 56 mg g -1) at ages 9 and 12 respectively. Comparison of traits within taxa between ages 9 and 12 found S/G ratios and glucose yields from untreated biomass were significantly lower in CT, CCV and hybrid taxa. As a result, the formation of lignocellulosic cell walls is complex, influenced by genetics and age of material, requiring optimization of rotation age for biofuel production and other industrial processes.« less

The effectiveness of scoliosis screening programs: methods for systematic review and expert panel recommendations formulation

PubMed Central

2013-01-01

Background Literature on scoliosis screening is vast, however because of the observational nature of available data and methodological flaws, data interpretation is often complex, leading to incomplete and sometimes, somewhat misleading conclusions. The need to propose a set of methods for critical appraisal of the literature about scoliosis screening, a comprehensive summary and rating of the available evidence appeared essential. Methods To address these gaps, the study aims were: i) To propose a framework for the assessment of published studies on scoliosis screening effectiveness; ii) To suggest specific questions to be answered on screening effectiveness instead of trying to reach a global position for or against the programs; iii) To contextualize the knowledge through expert panel consultation and meaningful recommendations. The general methodological approach proceeds through the following steps: Elaboration of the conceptual framework; Formulation of the review questions; Identification of the criteria for the review; Selection of the studies; Critical assessment of the studies; Results synthesis; Formulation and grading of recommendations in response to the questions. This plan follows at best GRADE Group (Grades of Recommendation, Assessment, Development and Evaluation) requirements for systematic reviews, assessing quality of evidence and grading the strength of recommendations. Conclusions In this article, the methods developed in support of this work are presented since they may be of some interest for similar reviews in scoliosis and orthopaedic fields. PMID:23883346

CORALINA: a universal method for the generation of gRNA libraries for CRISPR-based screening.

PubMed

Köferle, Anna; Worf, Karolina; Breunig, Christopher; Baumann, Valentin; Herrero, Javier; Wiesbeck, Maximilian; Hutter, Lukas H; Götz, Magdalena; Fuchs, Christiane; Beck, Stephan; Stricker, Stefan H

2016-11-14

The bacterial CRISPR system is fast becoming the most popular genetic and epigenetic engineering tool due to its universal applicability and adaptability. The desire to deploy CRISPR-based methods in a large variety of species and contexts has created an urgent need for the development of easy, time- and cost-effective methods enabling large-scale screening approaches. Here we describe CORALINA (comprehensive gRNA library generation through controlled nuclease activity), a method for the generation of comprehensive gRNA libraries for CRISPR-based screens. CORALINA gRNA libraries can be derived from any source of DNA without the need of complex oligonucleotide synthesis. We show the utility of CORALINA for human and mouse genomic DNA, its reproducibility in covering the most relevant genomic features including regulatory, coding and non-coding sequences and confirm the functionality of CORALINA generated gRNAs. The simplicity and cost-effectiveness make CORALINA suitable for any experimental system. The unprecedented sequence complexities obtainable with CORALINA libraries are a necessary pre-requisite for less biased large scale genomic and epigenomic screens.

A Novel Two-Step Method for Screening Shade Tolerant Mutant Plants via Dwarfism

PubMed Central

Li, Wei; Katin-Grazzini, Lorenzo; Krishnan, Sanalkumar; Thammina, Chandra; El-Tanbouly, Rania; Yer, Huseyin; Merewitz, Emily; Guillard, Karl; Inguagiato, John; McAvoy, Richard J.; Liu, Zongrang; Li, Yi

2016-01-01

When subjected to shade, plants undergo rapid shoot elongation, which often makes them more prone to disease and mechanical damage. Shade-tolerant plants can be difficult to breed; however, they offer a substantial benefit over other varieties in low-light areas. Although perennial ryegrass (Lolium perenne L.) is a popular species of turf grasses because of their good appearance and fast establishment, the plant normally does not perform well under shade conditions. It has been reported that, in turfgrass, induced dwarfism can enhance shade tolerance. Here we describe a two-step procedure for isolating shade tolerant mutants of perennial ryegrass by first screening for dominant dwarf mutants, and then screening dwarf plants for shade tolerance. The two-step screening process to isolate shade tolerant mutants can be done efficiently with limited space at early seedling stages, which enables quick and efficient isolation of shade tolerant mutants, and thus facilitates development of shade tolerant new cultivars of turfgrasses. Using the method, we isolated 136 dwarf mutants from 300,000 mutagenized seeds, with 65 being shade tolerant (0.022%). When screened directly for shade tolerance, we recovered only four mutants from a population of 150,000 (0.003%) mutagenized seeds. One shade tolerant mutant, shadow-1, was characterized in detail. In addition to dwarfism, shadow-1 and its sexual progeny displayed high degrees of tolerance to both natural and artificial shade. We showed that endogenous gibberellin (GA) content in shadow-1 was higher than wild-type controls, and shadow-1 was also partially GA insensitive. Our novel, simple and effective two-step screening method should be applicable to breeding shade tolerant cultivars of turfgrasses, ground covers, and other economically important crop plants that can be used under canopies of existing vegetation to increase productivity per unit area of land. PMID:27752260

Enhanced production of raw starch degrading enzyme using agro-industrial waste mixtures by thermotolerant Rhizopus microsporus for raw cassava chip saccharification in ethanol production.

PubMed

Trakarnpaiboon, Srisakul; Srisuk, Nantana; Piyachomkwan, Kuakoon; Sakai, Kenji; Kitpreechavanich, Vichien

2017-09-14

In the present study, solid-state fermentation for the production of raw starch degrading enzyme was investigated by thermotolerant Rhizopus microsporus TISTR 3531 using a combination of agro-industrial wastes as substrates. The obtained crude enzyme was applied for hydrolysis of raw cassava starch and chips at low temperature and subjected to nonsterile ethanol production using raw cassava chips. The agro-industrial waste ratio was optimized using a simplex axial mixture design. The results showed that the substrate mixture consisting of rice bran:corncob:cassava bagasse at 8 g:10 g:2 g yielded the highest enzyme production of 201.6 U/g dry solid. The optimized condition for solid-state fermentation was found as 65% initial moisture content, 35°C, initial pH of 6.0, and 5 × 10 6 spores/mL inoculum, which gave the highest enzyme activity of 389.5 U/g dry solid. The enzyme showed high efficiency on saccharification of raw cassava starch and chips with synergistic activities of commercial α-amylase at 50°C, which promotes low-temperature bioethanol production. A high ethanol concentration of 102.2 g/L with 78% fermentation efficiency was achieved from modified simultaneous saccharification and fermentation using cofermentation of the enzymatic hydrolysate of 300 g raw cassava chips/L with cane molasses.

Ultra-high-throughput screening method for the directed evolution of glucose oxidase.

PubMed

Ostafe, Raluca; Prodanovic, Radivoje; Nazor, Jovana; Fischer, Rainer

2014-03-20

Glucose oxidase (GOx) is used in many industrial processes that could benefit from improved versions of the enzyme. Some improvements like higher activity under physiological conditions and thermal stability could be useful for GOx applications in biosensors and biofuel cells. Directed evolution is one of the currently available methods to engineer improved GOx variants. Here, we describe an ultra-high-throughput screening system for sorting the best enzyme variants generated by directed evolution that incorporates several methodological refinements: flow cytometry, in vitro compartmentalization, yeast surface display, fluorescent labeling of the expressed enzyme, delivery of glucose substrate to the reaction mixture through the oil phase, and covalent labeling of the cells with fluorescein-tyramide. The method enables quantitative screening of gene libraries to identify clones with improved activity and it also allows cells to be selected based not only on the overall activity but also on the specific activity of the enzyme. Copyright © 2014 Elsevier Ltd. All rights reserved.

Methods for efficient high-throughput screening of protein expression in recombinant Pichia pastoris strains.

PubMed

Camattari, Andrea; Weinhandl, Katrin; Gudiminchi, Rama K

2014-01-01

The methylotrophic yeast Pichia pastoris is becoming one of the favorite industrial workhorses for protein expression. Due to the widespread use of integration vectors, which generates significant clonal variability, screening methods allowing assaying hundreds of individual clones are of particular importance. Here we describe methods to detect and analyze protein expression, developed in a 96-well format for high-throughput screening of recombinant P. pastoris strains. The chapter covers essentially three common scenarios: (1) an enzymatic assay for proteins expressed in the cell cytoplasm, requiring cell lysis; (2) a whole-cell assay for a fungal cytochrome P450; and (3) a nonenzymatic assay for detection and quantification of tagged protein secreted into the supernatant.

Microengineering methods for cell-based microarrays and high-throughput drug-screening applications.

PubMed

Xu, Feng; Wu, JinHui; Wang, ShuQi; Durmus, Naside Gozde; Gurkan, Umut Atakan; Demirci, Utkan

2011-09-01

Screening for effective therapeutic agents from millions of drug candidates is costly, time consuming, and often faces concerns due to the extensive use of animals. To improve cost effectiveness, and to minimize animal testing in pharmaceutical research, in vitro monolayer cell microarrays with multiwell plate assays have been developed. Integration of cell microarrays with microfluidic systems has facilitated automated and controlled component loading, significantly reducing the consumption of the candidate compounds and the target cells. Even though these methods significantly increased the throughput compared to conventional in vitro testing systems and in vivo animal models, the cost associated with these platforms remains prohibitively high. Besides, there is a need for three-dimensional (3D) cell-based drug-screening models which can mimic the in vivo microenvironment and the functionality of the native tissues. Here, we present the state-of-the-art microengineering approaches that can be used to develop 3D cell-based drug-screening assays. We highlight the 3D in vitro cell culture systems with live cell-based arrays, microfluidic cell culture systems, and their application to high-throughput drug screening. We conclude that among the emerging microengineering approaches, bioprinting holds great potential to provide repeatable 3D cell-based constructs with high temporal, spatial control and versatility.

Microengineering Methods for Cell Based Microarrays and High-Throughput Drug Screening Applications

PubMed Central

Xu, Feng; Wu, JinHui; Wang, ShuQi; Durmus, Naside Gozde; Gurkan, Umut Atakan; Demirci, Utkan

2011-01-01

Screening for effective therapeutic agents from millions of drug candidates is costly, time-consuming and often face ethical concerns due to extensive use of animals. To improve cost-effectiveness, and to minimize animal testing in pharmaceutical research, in vitro monolayer cell microarrays with multiwell plate assays have been developed. Integration of cell microarrays with microfluidic systems have facilitated automated and controlled component loading, significantly reducing the consumption of the candidate compounds and the target cells. Even though these methods significantly increased the throughput compared to conventional in vitro testing systems and in vivo animal models, the cost associated with these platforms remains prohibitively high. Besides, there is a need for three-dimensional (3D) cell based drug-screening models, which can mimic the in vivo microenvironment and the functionality of the native tissues. Here, we present the state-of-the-art microengineering approaches that can be used to develop 3D cell based drug screening assays. We highlight the 3D in vitro cell culture systems with live cell-based arrays, microfluidic cell culture systems, and their application to high-throughput drug screening. We conclude that among the emerging microengineering approaches, bioprinting holds a great potential to provide repeatable 3D cell based constructs with high temporal, spatial control and versatility. PMID:21725152

Methods for external event screening quantification: Risk Methods Integration and Evaluation Program (RMIEP) methods development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ravindra, M.K.; Banon, H.

1992-07-01

In this report, the scoping quantification procedures for external events in probabilistic risk assessments of nuclear power plants are described. External event analysis in a PRA has three important goals; (1) the analysis should be complete in that all events are considered; (2) by following some selected screening criteria, the more significant events are identified for detailed analysis; (3) the selected events are analyzed in depth by taking into account the unique features of the events: hazard, fragility of structures and equipment, external-event initiated accident sequences, etc. Based on the above goals, external event analysis may be considered as amore » three-stage process: Stage I: Identification and Initial Screening of External Events; Stage II: Bounding Analysis; Stage III: Detailed Risk Analysis. In the present report, first, a review of published PRAs is given to focus on the significance and treatment of external events in full-scope PRAs. Except for seismic, flooding, fire, and extreme wind events, the contributions of other external events to plant risk have been found to be negligible. Second, scoping methods for external events not covered in detail in the NRC's PRA Procedures Guide are provided. For this purpose, bounding analyses for transportation accidents, extreme winds and tornadoes, aircraft impacts, turbine missiles, and chemical release are described.« less

Methods for external event screening quantification: Risk Methods Integration and Evaluation Program (RMIEP) methods development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ravindra, M.K.; Banon, H.

1992-07-01

In this report, the scoping quantification procedures for external events in probabilistic risk assessments of nuclear power plants are described. External event analysis in a PRA has three important goals; (1) the analysis should be complete in that all events are considered; (2) by following some selected screening criteria, the more significant events are identified for detailed analysis; (3) the selected events are analyzed in depth by taking into account the unique features of the events: hazard, fragility of structures and equipment, external-event initiated accident sequences, etc. Based on the above goals, external event analysis may be considered as amore » three-stage process: Stage I: Identification and Initial Screening of External Events; Stage II: Bounding Analysis; Stage III: Detailed Risk Analysis. In the present report, first, a review of published PRAs is given to focus on the significance and treatment of external events in full-scope PRAs. Except for seismic, flooding, fire, and extreme wind events, the contributions of other external events to plant risk have been found to be negligible. Second, scoping methods for external events not covered in detail in the NRC`s PRA Procedures Guide are provided. For this purpose, bounding analyses for transportation accidents, extreme winds and tornadoes, aircraft impacts, turbine missiles, and chemical release are described.« less

A new versatile microarray-based method for high throughput screening of carbohydrate-active enzymes.

PubMed

Vidal-Melgosa, Silvia; Pedersen, Henriette L; Schückel, Julia; Arnal, Grégory; Dumon, Claire; Amby, Daniel B; Monrad, Rune Nygaard; Westereng, Bjørge; Willats, William G T

2015-04-03

Carbohydrate-active enzymes have multiple biological roles and industrial applications. Advances in genome and transcriptome sequencing together with associated bioinformatics tools have identified vast numbers of putative carbohydrate-degrading and -modifying enzymes including glycoside hydrolases and lytic polysaccharide monooxygenases. However, there is a paucity of methods for rapidly screening the activities of these enzymes. By combining the multiplexing capacity of carbohydrate microarrays with the specificity of molecular probes, we have developed a sensitive, high throughput, and versatile semiquantitative enzyme screening technique that requires low amounts of enzyme and substrate. The method can be used to assess the activities of single enzymes, enzyme mixtures, and crude culture broths against single substrates, substrate mixtures, and biomass samples. Moreover, we show that the technique can be used to analyze both endo-acting and exo-acting glycoside hydrolases, polysaccharide lyases, carbohydrate esterases, and lytic polysaccharide monooxygenases. We demonstrate the potential of the technique by identifying the substrate specificities of purified uncharacterized enzymes and by screening enzyme activities from fungal culture broths. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

A New Versatile Microarray-based Method for High Throughput Screening of Carbohydrate-active Enzymes*

PubMed Central

Vidal-Melgosa, Silvia; Pedersen, Henriette L.; Schückel, Julia; Arnal, Grégory; Dumon, Claire; Amby, Daniel B.; Monrad, Rune Nygaard; Westereng, Bjørge; Willats, William G. T.

2015-01-01

Carbohydrate-active enzymes have multiple biological roles and industrial applications. Advances in genome and transcriptome sequencing together with associated bioinformatics tools have identified vast numbers of putative carbohydrate-degrading and -modifying enzymes including glycoside hydrolases and lytic polysaccharide monooxygenases. However, there is a paucity of methods for rapidly screening the activities of these enzymes. By combining the multiplexing capacity of carbohydrate microarrays with the specificity of molecular probes, we have developed a sensitive, high throughput, and versatile semiquantitative enzyme screening technique that requires low amounts of enzyme and substrate. The method can be used to assess the activities of single enzymes, enzyme mixtures, and crude culture broths against single substrates, substrate mixtures, and biomass samples. Moreover, we show that the technique can be used to analyze both endo-acting and exo-acting glycoside hydrolases, polysaccharide lyases, carbohydrate esterases, and lytic polysaccharide monooxygenases. We demonstrate the potential of the technique by identifying the substrate specificities of purified uncharacterized enzymes and by screening enzyme activities from fungal culture broths. PMID:25657012

Danish method study on cervical screening in women offered HPV vaccination as girls (Trial23): a study protocol.

PubMed

Thamsborg, Lise Holst; Andersen, Berit; Larsen, Lise Grupe; Christensen, Jette; Johansen, Tonje; Hariri, Jalil; Christiansen, Sanne; Rygaard, Carsten; Lynge, Elsebeth

2018-05-26

The first birth cohorts of women offered human papillomavirus (HPV) vaccination as girls are now entering cervical screening. However, there is no international consensus on how to screen HPV vaccinated women. These women are better protected against cervical cancer and could therefore be offered less intensive screening. Primary HPV testing is more sensitive than cytology, allowing for a longer screening interval. The aim of Trial23 is to investigate if primary HPV testing with cytology triage of HPV positive samples is a reasonable screening scheme for women offered HPV vaccination as girls. Trial23 is a method study embedded in the existing cervical screening programme in four out of five Danish regions. Without affecting the screening programme, women born in 1994 are randomised to present screening with liquid-based cytology every third year (present programme arm) or present screening plus an HPV test (HPV arm). The study started 1 February 2017 and will run over three screening rounds corresponding to 7-8 years. The primary endpoint is cervical intraepithelial neoplasia grade 3 or above. The trial is undertaken as a non-inferiority study including intention-to-treat and per-protocol analyses. The potential effect of primary HPV screening with a 6-year interval will be calculated from the observed data. The study protocol has been submitted to the ethical committee and deemed a method study. All women are screened according to routine guidelines. The study will contribute new evidence on the future screening of HPV vaccinated birth cohorts of women. All results will be published in open-access journal. NCT03049553; Pre-results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Comparison of Instructional Methods for Screening, Brief Intervention, and Referral to Treatment for Substance Use in Nursing Education.

PubMed

Knopf-Amelung, Sarah; Gotham, Heather; Kuofie, Araba; Young, Pamela; Manney Stinson, Ronalda; Lynn, Jolene; Barker, Kendra; Hildreth, Jessica

Most nursing programs lack curriculum on substance use. This project evaluated 3 didactic instructional methods for teaching baccalaureate nursing students about screening, brief intervention, and referral to treatment for substance use. In-person, asynchronous narrated slides and interactive online instructional methods were all effective in developing students' competency; however, active learning methods (in-person and interactive online course) were more effective in changing students' attitudes about their role in screening and intervening for drug use.

Improvement of enzymatic saccharification of Populus and switchgrass by combined pretreatment with steam and wet disk milling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumagai, Akio; Wu, Long; Iwamoto, Shinichiro

In this study, to reduce the recalcitrance of lignocellulosic biomass for subsequent biological processing, we pretreated energy crop feedstocks with mild steam treatment (ST; 130 and 150 °C for 60 min) and wet disk milling (WDM). We tested two phylogenetically different, but typical energy crop feedstocks: Populus trichocarpa and switchgrass ( Panicum virgatum). WDM after ST facilitated the fibrillation of both types of biomass, resulting in an increase of specific surface area, improved enzymatic saccharification yield, and decrease in cellulose crystallinity. Lastly, after steam treatment at 150 °C followed by 17 cycles of WDM, enzymatic hydrolysis resulted in almost completemore » glucan to glucose conversion in both feedstocks.« less

Improvement of enzymatic saccharification of Populus and switchgrass by combined pretreatment with steam and wet disk milling

DOE PAGES

Kumagai, Akio; Wu, Long; Iwamoto, Shinichiro; ...

2014-12-15

In this study, to reduce the recalcitrance of lignocellulosic biomass for subsequent biological processing, we pretreated energy crop feedstocks with mild steam treatment (ST; 130 and 150 °C for 60 min) and wet disk milling (WDM). We tested two phylogenetically different, but typical energy crop feedstocks: Populus trichocarpa and switchgrass ( Panicum virgatum). WDM after ST facilitated the fibrillation of both types of biomass, resulting in an increase of specific surface area, improved enzymatic saccharification yield, and decrease in cellulose crystallinity. Lastly, after steam treatment at 150 °C followed by 17 cycles of WDM, enzymatic hydrolysis resulted in almost completemore » glucan to glucose conversion in both feedstocks.« less

A Novel Approach for Efficient Pharmacophore-based Virtual Screening: Method and Applications

PubMed Central

Dror, Oranit; Schneidman-Duhovny, Dina; Inbar, Yuval; Nussinov, Ruth; Wolfson, Haim J.

2009-01-01

Virtual screening is emerging as a productive and cost-effective technology in rational drug design for the identification of novel lead compounds. An important model for virtual screening is the pharmacophore. Pharmacophore is the spatial configuration of essential features that enable a ligand molecule to interact with a specific target receptor. In the absence of a known receptor structure, a pharmacophore can be identified from a set of ligands that have been observed to interact with the target receptor. Here, we present a novel computational method for pharmacophore detection and virtual screening. The pharmacophore detection module is able to: (i) align multiple flexible ligands in a deterministic manner without exhaustive enumeration of the conformational space, (ii) detect subsets of input ligands that may bind to different binding sites or have different binding modes, (iii) address cases where the input ligands have different affinities by defining weighted pharmacophores based on the number of ligands that share them, and (iv) automatically select the most appropriate pharmacophore candidates for virtual screening. The algorithm is highly efficient, allowing a fast exploration of the chemical space by virtual screening of huge compound databases. The performance of PharmaGist was successfully evaluated on a commonly used dataset of G-Protein Coupled Receptor alpha1A. Additionally, a large-scale evaluation using the DUD (directory of useful decoys) dataset was performed. DUD contains 2950 active ligands for 40 different receptors, with 36 decoy compounds for each active ligand. PharmaGist enrichment rates are comparable with other state-of-the-art tools for virtual screening. Availability The software is available for download. A user-friendly web interface for pharmacophore detection is available at http://bioinfo3d.cs.tau.ac.il/PharmaGist. PMID:19803502

From molecular engineering to process engineering: development of high-throughput screening methods in enzyme directed evolution.

PubMed

Ye, Lidan; Yang, Chengcheng; Yu, Hongwei

2018-01-01

With increasing concerns in sustainable development, biocatalysis has been recognized as a competitive alternative to traditional chemical routes in the past decades. As nature's biocatalysts, enzymes are able to catalyze a broad range of chemical transformations, not only with mild reaction conditions but also with high activity and selectivity. However, the insufficient activity or enantioselectivity of natural enzymes toward non-natural substrates limits their industrial application, while directed evolution provides a potent solution to this problem, thanks to its independence on detailed knowledge about the relationship between sequence, structure, and mechanism/function of the enzymes. A proper high-throughput screening (HTS) method is the key to successful and efficient directed evolution. In recent years, huge varieties of HTS methods have been developed for rapid evaluation of mutant libraries, ranging from in vitro screening to in vivo selection, from indicator addition to multi-enzyme system construction, and from plate screening to computation- or machine-assisted screening. Recently, there is a tendency to integrate directed evolution with metabolic engineering in biosynthesis, using metabolites as HTS indicators, which implies that directed evolution has transformed from molecular engineering to process engineering. This paper aims to provide an overview of HTS methods categorized based on the reaction principles or types by summarizing related studies published in recent years including the work from our group, to discuss assay design strategies and typical examples of HTS methods, and to share our understanding on HTS method development for directed evolution of enzymes involved in specific catalytic reactions or metabolic pathways.

Cost and effectiveness comparison of two methods for screening potential blood donors for anaemia in Vietnam.

PubMed

Tyrrell, A; Worrall, E; Que, T N; Bates, I

2011-06-01

To compare the cost and effectiveness of Copper Sulphate (CS) and HemoCue (HC) methods for screening blood donors for anaemia. Robust information from developing countries about cost and effectiveness of anaemia screening methods for blood donors is scarce. In such countries there are widespread shortages of blood, so the most cost-effective method should maximise blood supply without compromising donor safety. Economic data (e.g. staff time, equipment and buildings) were collected from direct observation of procedures and purchase data from Hanoi's Central Blood Bank administrative department. A framework for comparing the cost and effectiveness of anaemia screening methods was developed and a cost per effective (i.e. usable and accurate) test was generated for each method. Samples from 100 potential donors from the Hanoi Central Blood Bank (static) and 198 from two mobile units were tested. The mean probability of an ineffective anaemia test was 0·1 (0·05-0·2). The average cost of an HC test was $0·75 (static $0·61 and mobile $0·89) and a CS test was $0·31 (static $0·17 and mobile $0·45). The difference between static and mobile units was predominantly due to transport costs; the difference between the two methods was predominantly due to the HC microcuvettes. In this setting the CS yields greater value for money than the HC method for screening blood donors. The relative cost and effectiveness of CS and HC may be different in places with higher staff turnover, lower test accuracy, higher anaemia prevalence or lower workload than in Vietnam. © 2010 Liverpool School of Tropical Medicine. Transfusion Medicine © 2010 British Blood Transfusion Society.

Prediction of Phase Behavior of Spray-Dried Amorphous Solid Dispersions: Assessment of Thermodynamic Models, Standard Screening Methods and a Novel Atomization Screening Device with Regard to Prediction Accuracy

PubMed Central

Chavez, Pierre-François; Meeus, Joke; Robin, Florent; Schubert, Martin Alexander; Somville, Pascal

2018-01-01

The evaluation of drug–polymer miscibility in the early phase of drug development is essential to ensure successful amorphous solid dispersion (ASD) manufacturing. This work investigates the comparison of thermodynamic models, conventional experimental screening methods (solvent casting, quench cooling), and a novel atomization screening device based on their ability to predict drug–polymer miscibility, solid state properties (Tg value and width), and adequate polymer selection during the development of spray-dried amorphous solid dispersions (SDASDs). Binary ASDs of four drugs and seven polymers were produced at 20:80, 40:60, 60:40, and 80:20 (w/w). Samples were systematically analyzed using modulated differential scanning calorimetry (mDSC) and X-ray powder diffraction (XRPD). Principal component analysis (PCA) was used to qualitatively assess the predictability of screening methods with regards to SDASD development. Poor correlation was found between theoretical models and experimentally-obtained results. Additionally, the limited ability of usual screening methods to predict the miscibility of SDASDs did not guarantee the appropriate selection of lead excipient for the manufacturing of robust SDASDs. Contrary to standard approaches, our novel screening device allowed the selection of optimal polymer and drug loading and established insight into the final properties and performance of SDASDs at an early stage, therefore enabling the optimization of the scaled-up late-stage development. PMID:29518936

Efficacy of ACL injury risk screening methods in identifying high-risk landing patterns during a sport-specific task.

PubMed

Fox, A S; Bonacci, J; McLean, S G; Saunders, N

2017-05-01

Screening methods sensitive to movement strategies that increase anterior cruciate ligament (ACL) loads are likely to be effective in identifying athletes at-risk of ACL injury. Current ACL injury risk screening methods are yet to be evaluated for their ability to identify athletes' who exhibit high-risk lower limb mechanics during sport-specific maneuvers associated with ACL injury occurrences. The purpose of this study was to examine the efficacy of two ACL injury risk screening methods in identifying high-risk lower limb mechanics during a sport-specific landing task. Thirty-two female athletes were screened using the Landing Error Scoring System (LESS) and Tuck Jump Assessment. Participants' also completed a sport-specific landing task, during which three-dimensional kinematic and kinetic data were collected. One-dimensional statistical parametric mapping was used to examine the relationships between screening method scores, and the three-dimensional hip and knee joint rotation and moment data from the sport-specific landing. Higher LESS scores were associated with reduced knee flexion from 30 to 57 ms after initial contact (P = 0.003) during the sport-specific landing; however, no additional relationships were found. These findings suggest the LESS and Tuck Jump Assessment may have minimal applicability in identifying athletes' who exhibit high-risk landing postures in the sport-specific task examined. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Evaluation of a QuECHERS-like extraction approach for the determination of PBDEs in mussels by immuno-assay-based screening methods

USDA-ARS?s Scientific Manuscript database

A sample preparation method was evaluated for the determination of polybrominated diphenyl ethers (PBDEs) in mussel samples, by using colorimetric and electrochemical immunoassay-based screening methods. A simple sample preparation in conjunction with a rapid screening method possesses the desired c...

Pretreatment of woody and herbaceous biomass for enzymatic saccharification using sulfuric acid-free ethanol cooking.

PubMed

Teramoto, Yoshikuni; Lee, Seung-Hwan; Endo, Takashi

2008-12-01

A sulfuric acid-free ethanol cooking (SFEC) treatment was developed to achieve complete saccharification of the cellulosic component of eucalyptus and baggase flour, thereby avoiding the problems associated with the use of strong acid catalysts. Cutter-milled flours were exposed to an ethanol (EtOH)/water/acetic acid mixture in an autoclave. Enzymatic hydrolysis experiments of the pretreated samples demonstrated that almost complete conversion of the cellulosic components to glucose was achieved under optimal conditions. A large-scale trial revealed that there was little consumption of in-feed EtOH during SFEC; therefore, it is considered that most part EtOH used can be essentially recovered and reused. Field emission scanning electron microscopy showed that SFEC induced the formation of pores ranging in size from approximately 10 to several 100nm. It can be assumed that the porous surface was due to the partial removals of lignin and hemicellulose, which improved the accessibility of the enzyme onto the substrate.

Comparison of different screening methods for blood pressure disorders in children and adolescents.

PubMed

Mourato, Felipe Alves; Lima Filho, José Luiz; Mattos, Sandra da Silva

2015-01-01

To compare different methods of screening for blood pressure disorders in children and adolescents. A database with 17,083 medical records of patients from a pediatric cardiology clinic was used. After analyzing the inclusion and exclusion criteria, 5,650 were selected. These were divided into two age groups: between 5 and 13 years and between 13 and 18 years. The blood pressure measurement was classified as normal, pre-hypertensive, or hypertensive, consistent with recent guidelines and the selected screening methods. Sensitivity, specificity, and accuracy were then calculated according to gender and age range. The formulas proposed by Somu and Ardissino's table showed low sensitivity in identifying pre-hypertension in all age groups, whereas the table proposed by Kaelber showed the best results. The ratio between blood pressure and height showed low specificity in the younger age group, but showed good performance in adolescents. Screening tools used for the assessment of blood pressure disorders in children and adolescents may be useful to decrease the current rate of underdiagnosis of this condition. The table proposed by Kaelber showed the best results; however, the ratio between BP and height demonstrated specific advantages, as it does not require tables. Copyright © 2014 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

A simple, fast and sensitive screening LC-ESI-MS/MS method for antibiotics in fish.

PubMed

Guidi, Letícia Rocha; Santos, Flávio Alves; Ribeiro, Ana Cláudia S R; Fernandes, Christian; Silva, Luiza H M; Gloria, Maria Beatriz A

2017-01-15

The objective of this study was to develop and validate a fast, sensitive and simple liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) method for the screening of six classes of antibiotics (aminoglycosides, beta-lactams, macrolides, quinolones, sulfonamides and tetracyclines) in fish. Samples were extracted with trichloroacetic acid. LC separation was achieved on a Zorbax Eclipse XDB C18 column and gradient elution using 0.1% heptafluorobutyric acid in water and acetonitrile as mobile phase. Analysis was carried out in multiple reaction monitoring mode via electrospray interface operated in the positive ionization mode, with sulfaphenazole as internal standard. The method was suitable for routine screening purposes of 40 antibiotics, according to EC Guidelines for the Validation of Screening Methods for Residues of Veterinary Medicines, taking into consideration threshold value, cut-off factor, detection capability, limit of detection, sensitivity and specificity. Real fish samples (n=193) from aquaculture were analyzed and 15% were positive for enrofloxacin (quinolone), one of them at a higher concentration than the level of interest (50µgkg -1 ), suggesting possible contamination or illegal use of that antibiotic. Copyright © 2016 Elsevier B.V. All rights reserved.

Saccharification of rice straw by cellulase from a local Trichoderma harzianum SNRS3 for biobutanol production.

PubMed

Rahnama, Nooshin; Foo, Hooi Ling; Abdul Rahman, Nor Aini; Ariff, Arbakariya; Md Shah, Umi Kalsom

2014-12-12

Rice straw has shown to be a promising agricultural by-product in the bioconversion of biomass to value-added products. Hydrolysis of cellulose, a main constituent of lignocellulosic biomass, is a requirement for fermentable sugar production and its subsequent bioconversion to biofuels such as biobutanol. The high cost of commercial enzymes is a major impediment to the industrial application of cellulases. Therefore, the use of local microbial enzymes has been suggested. Trichoderma harzianum strains are potential CMCase and β-glucosidase producers. However, few researches have been reported on cellulase production by T. harzianum and the subsequent use of the crude cellulase for cellulose enzymatic hydrolysis. For cellulose hydrolysis to be efficiently performed, the presence of the whole set of cellulase components including exoglucanase, endoglucanase, and β-glucosidase at a considerable concentration is required. Biomass recalcitrance is also a bottleneck in the bioconversion of agricultural residues to value-added products. An effective pretreatment could be of central significance in the bioconversion of biomass to biofuels. Rice straw pretreated using various concentrations of NaOH was subjected to enzymatic hydrolysis. The saccharification of rice straw pretreated with 2% (w/v) NaOH using crude cellulase from local T. harzianum SNRS3 resulted in the production of 29.87 g/L reducing sugar and a yield of 0.6 g/g substrate. The use of rice straw hydrolysate as carbon source for biobutanol fermentation by Clostridium acetobutylicum ATCC 824 resulted in an ABE yield, ABE productivity, and biobutanol yield of 0.27 g/g glucose, 0.04 g/L/h and 0.16 g/g glucose, respectively. As a potential β-glucosidase producer, T. harzianum SNRS3 used in this study was able to produce β-glucosidase at the activity of 173.71 U/g substrate. However, for cellulose hydrolysis to be efficient, Filter Paper Activity at a considerable concentration is also required to initiate the

Survey of South African fruit juices using a fast screening HILIC-MS method.

PubMed

Stander, Marietjie A; Kühn, Wernich; Hiten, Nicholas F

2013-01-01

Adulteration of fruit juices--by the addition of sugar or other less expensive fruit juices as well as preservatives, artificial sweeteners and colours--was tested for by using a developed screening method. The method employs hydrophilic interaction liquid chromatography-mass spectrometry (HILIC-MS) using electrospray ionisation in the negative mode and ultraviolet light detection. Different fruit juices can be differentiated by the content of marker compounds like sorbitol, certain phenolic molecules and their saccharide profile. This method was used to test 46 fruit juice samples from the retail market as well as 12 control samples. The study focused on the main types of fruit juices consumed on the South African market including apple, orange, grape and blends of these juices with other fruits like mango, pear and guava. Overall, the 46 samples tested mostly agreed with label claims. One grape juice sample was adulterated, probably with apple juice. Natamycin above the legal limits was found in two samples. In addition, two samples contained natamycin and one sample benzoate without it being indicated on the label. The method is well suited as a quick screening method for fruit juice adulteration and if used routinely would reduce fruit juice adulteration without the cost of the current array of tests needed for authenticity testing.

Acetone-butanol-ethanol production from Kraft paper mill sludge by simultaneous saccharification and fermentation.

PubMed

Guan, Wenjian; Shi, Suan; Tu, Maobing; Lee, Yoon Y

2016-01-01

Paper mill sludge (PS), a solid waste from pulp and paper industry, was investigated as a feedstock for acetone-butanol-ethanol (ABE) production by simultaneous saccharification and fermentation (SSF). ABE fermentation of paper sludge by Clostridium acetobutylicum required partial removal of ash in PS to enhance its enzymatic digestibility. Enzymatic hydrolysis was found to be a rate-limiting step in the SSF. A total of 16.4-18.0g/L of ABE solvents were produced in the SSF of de-ashed PS with solid loading of 6.3-7.4% and enzyme loading of 10-15FPU/g-glucan, and the final solvent yield reached 0.27g/g sugars. No pretreatment and pH control were needed in ABE fermentation of paper sludge, which makes it an attractive feedstock for butanol production. The results suggested utilization of paper sludge should not only consider the benefits of buffering effect of CaCO3 in fermentation, but also take into account its inhibitory effect on enzymatic hydrolysis. Published by Elsevier Ltd.

Screening portal, system and method of using same

DOEpatents

Linker, Kevin L.; Hunter, John A.; Brusseau, Charles A.

2013-04-30

A portal, system and method for screening an object for a target substance is provided. The portal includes an inflatable bladder expandable to form a test space for receiving the object and a plurality of nozzles positioned about the inflatable bladder. The nozzles are in fluid communication with a fluid source for directing air over the object whereby samples are removed from the object for examination. A collector is operatively connected to the inflatable bladder for collecting the samples removed from the object. A detector is operatively connected to the collector for examining the removed samples for the presence of the target substance. At least one preconcentrator may be operatively connected to the collector for concentrating the samples collected thereby.

Parallel production and verification of protein products using a novel high-throughput screening method.

PubMed

Tegel, Hanna; Yderland, Louise; Boström, Tove; Eriksson, Cecilia; Ukkonen, Kaisa; Vasala, Antti; Neubauer, Peter; Ottosson, Jenny; Hober, Sophia

2011-08-01

Protein production and analysis in a parallel fashion is today applied in laboratories worldwide and there is a great need to improve the techniques and systems used for this purpose. In order to save time and money, a fast and reliable screening method for analysis of protein production and also verification of the protein product is desired. Here, a micro-scale protocol for the parallel production and screening of 96 proteins in plate format is described. Protein capture was achieved using immobilized metal affinity chromatography and the product was verified using matrix-assisted laser desorption ionization time-of-flight MS. In order to obtain sufficiently high cell densities and product yield in the small-volume cultivations, the EnBase® cultivation technology was applied, which enables cultivation in as small volumes as 150 μL. Here, the efficiency of the method is demonstrated by producing 96 human, recombinant proteins, both in micro-scale and using a standard full-scale protocol and comparing the results in regard to both protein identity and sample purity. The results obtained are highly comparable to those acquired through employing standard full-scale purification protocols, thus validating this method as a successful initial screening step before protein production at a larger scale. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Using quality improvement methods to optimize resources and maximize productivity in an anesthesia screening and consultation clinic.

PubMed

Varughese, Anna M; Hagerman, Nancy; Townsend, Mari E

2013-07-01

The anesthesia preoperative screening and evaluation of a patient prior to surgery is a critical element in the safe and effective delivery of anesthesia care. In this era of increased focus on cost containment, many anesthesia practices are looking for ways to maximize productivity while maintaining the quality of the preoperative evaluation process by harnessing and optimizing all available resources. We sought to develop a Nurse Practitioner-assisted Preoperative Anesthesia Screening process using quality improvement methods with the goal of maintaining the quality of the screening process, while at the same time redirecting anesthesiologists time for the provision of nonoperating room (OR) anesthesia. The Nurse practitioner (NP) time (approximately 10 h per week) directed to this project was gained as a result of an earlier resource utilization improvement project within the Department of Anesthesia. The goal of this improvement project was to increase the proportion of patient anesthesia screens conducted by NPs to 50% within 6 months. After discussion with key stakeholders of the process, a multidisciplinary improvement team identified a set of operational factors (key drivers) believed to be important to the success of the preoperative anesthesia screening process. These included the development of dedicated NP time for daily screening, NP competency and confidence with the screening process, effective mentoring by anesthesiologists, standardization of screening process, and communication with stakeholders of the process, that is, surgeons. These key drivers focused on the development of several interventions such as (i) NP education in the preoperative anesthesia screening for consultation process by a series of didactic lectures conducted by anesthesiologists, and NP's shadowing an anesthesiologist during the screening process, (ii) Anesthesiologist mentoring and assessment of NP screenings using the dual screening process whereby both anesthesiologists

Simultaneous saccharification and bioethanol production from corn cobs: Process optimization and kinetic studies.

PubMed

Sewsynker-Sukai, Yeshona; Gueguim Kana, E B

2018-08-01

This study investigates the simultaneous saccharification and fermentation (SSF) process for bioethanol production from corn cobs with prehydrolysis (PSSF) and without prehydrolysis (OSSF). Two response surface models were developed with high coefficients of determination (>0.90). Process optimization gave high bioethanol concentrations and bioethanol conversions for the PSSF (36.92 ± 1.34 g/L and 62.36 ± 2.27%) and OSSF (35.04 ± 0.170 g/L and 58.13 ± 0.283%) models respectively. Additionally, the logistic and modified Gompertz models were used to study the kinetics of microbial cell growth and ethanol formation under microaerophilic and anaerobic conditions. Cell growth in the OSSF microaerophilic process gave the highest maximum specific growth rate (µ max ) of 0.274 h -1 . The PSSF microaerophilic bioprocess gave the highest potential maximum bioethanol concentration (P m ) (42.24 g/L). This study demonstrated that microaerophilic rather than anaerobic culture conditions enhanced cell growth and bioethanol production, and that additional prehydrolysis steps do not significantly impact on the bioethanol concentration and conversion in SSF process. Copyright © 2018 Elsevier Ltd. All rights reserved.

The operable modeling of simultaneous saccharification and fermentation of ethanol production from cellulose.

PubMed

Shen, Jiacheng; Agblevor, Foster A

2010-03-01

An operable batch model of simultaneous saccharification and fermentation (SSF) for ethanol production from cellulose has been developed. The model includes four ordinary differential equations that describe the changes of cellobiose, glucose, yeast, and ethanol concentrations with respect to time. These equations were used to simulate the experimental data of the four main components in the SSF process of ethanol production from microcrystalline cellulose (Avicel PH101). The model parameters at 95% confidence intervals were determined by a MATLAB program based on the batch experimental data of the SSF. Both experimental data and model simulations showed that the cell growth was the rate-controlling step at the initial period in a series of reactions of cellulose to ethanol, and later, the conversion of cellulose to cellobiose controlled the process. The batch model was extended to the continuous and fed-batch operating models. For the continuous operation in the SSF, the ethanol productivities increased with increasing dilution rate, until a maximum value was attained, and rapidly decreased as the dilution rate approached the washout point. The model also predicted a relatively high ethanol mass for the fed-batch operation than the batch operation.

Optimal Methods to Screen Men and Women for Intimate Partner Violence: Results from an Internal Medicine Residency Continuity Clinic

ERIC Educational Resources Information Center

Kapur, Nitin A.; Windish, Donna M.

2011-01-01

Contradictory data exist regarding optimal methods and instruments for intimate partner violence (IPV) screening in primary care settings. The purpose of this study was to determine the optimal method and screening instrument for IPV among men and women in a primary-care resident clinic. We conducted a cross-sectional study at an urban, academic,…

A mix-and-read drop-based in vitro two-hybrid method for screening high-affinity peptide binders

PubMed Central

Cui, Naiwen; Zhang, Huidan; Schneider, Nils; Tao, Ye; Asahara, Haruichi; Sun, Zhiyi; Cai, Yamei; Koehler, Stephan A.; de Greef, Tom F. A.; Abbaspourrad, Alireza; Weitz, David A.; Chong, Shaorong

2016-01-01

Drop-based microfluidics have recently become a novel tool by providing a stable linkage between phenotype and genotype for high throughput screening. However, use of drop-based microfluidics for screening high-affinity peptide binders has not been demonstrated due to the lack of a sensitive functional assay that can detect single DNA molecules in drops. To address this sensitivity issue, we introduced in vitro two-hybrid system (IVT2H) into microfluidic drops and developed a streamlined mix-and-read drop-IVT2H method to screen a random DNA library. Drop-IVT2H was based on the correlation between the binding affinity of two interacting protein domains and transcriptional activation of a fluorescent reporter. A DNA library encoding potential peptide binders was encapsulated with IVT2H such that single DNA molecules were distributed in individual drops. We validated drop-IVT2H by screening a three-random-residue library derived from a high-affinity MDM2 inhibitor PMI. The current drop-IVT2H platform is ideally suited for affinity screening of small-to-medium-sized libraries (103–106). It can obtain hits within a single day while consuming minimal amounts of reagents. Drop-IVT2H simplifies and accelerates the drop-based microfluidics workflow for screening random DNA libraries, and represents a novel alternative method for protein engineering and in vitro directed protein evolution. PMID:26940078

Recommendations for Developing Alternative Test Methods for Screening and Prioritization of Chemicals for Developmental Neurotoxicity

EPA Science Inventory

Developmental neurotoxicity testing (DNT) is perceived by many stakeholders to be an area in critical need of alternative methods to current animal testing protocols and gUidelines. An immediate goal is to develop test methods that are capable of screening large numbers of chemic...

A review on EEG-based methods for screening and diagnosing alcohol use disorder.

PubMed

Mumtaz, Wajid; Vuong, Pham Lam; Malik, Aamir Saeed; Rashid, Rusdi Bin Abd

2018-04-01

The screening test for alcohol use disorder (AUD) patients has been of subjective nature and could be misleading in particular cases such as a misreporting the actual quantity of alcohol intake. Although the neuroimaging modality such as electroencephalography (EEG) has shown promising research results in achieving objectivity during the screening and diagnosis of AUD patients. However, the translation of these findings for clinical applications has been largely understudied and hence less clear. This study advocates the use of EEG as a diagnostic and screening tool for AUD patients that may help the clinicians during clinical decision making. In this context, a comprehensive review on EEG-based methods is provided including related electrophysiological techniques reported in the literature. More specifically, the EEG abnormalities associated with the conditions of AUD patients are summarized. The aim is to explore the potentials of objective techniques involving quantities/features derived from resting EEG, event-related potentials or event-related oscillations data.

Method for screening prevention and control measures and technologies based on groundwater pollution intensity assessment.

PubMed

Li, Juan; Yang, Yang; Huan, Huan; Li, Mingxiao; Xi, Beidou; Lv, Ningqing; Wu, Yi; Xie, Yiwen; Li, Xiang; Yang, Jinjin

2016-05-01

This paper presents a system for determining the evaluation and gradation indices of groundwater pollution intensity (GPI). Considering the characteristics of the vadose zone and pollution sources, the system decides which anti-seepage measures should be implemented at the contaminated site. The pollution sources hazards (PSH) and groundwater intrinsic vulnerability (GIV) are graded by the revised Nemerow Pollution Index and an improved DRTAS model, respectively. GPI is evaluated and graded by a double-sided multi-factor coupling model, which is constructed by the matrix method. The contaminated sites are categorized as prior, ordinary, or common sites. From the GPI results, we develop guiding principles for preventing and removing pollution sources, procedural interruption and remediation, and end treatment and monitoring. Thus, we can select appropriate prevention and control technologies (PCT). To screen the technological schemes and optimize the traditional analytical hierarchy process (AHP), we adopt the technique for order preference by the similarity to ideal solution (TOPSIS) method. Our GPI approach and PCT screening are applied to three types of pollution sites: the refuse dump of a rare earth mine development project (a potential pollution source), a chromium slag dump, and a landfill (existing pollution sources). These three sites are identified as ordinary, prior, and ordinary sites, respectively. The anti-seepage materials at the refuse dump should perform as effectively as a 1.5-m-thick clay bed. The chromium slag dump should be preferentially treated by soil flushing and in situ chemical remediation. The landfill should be treated by natural attenuation technology. The proposed PCT screening approach was compared with conventional screening methods results at the three sites and proved feasible and effective. The proposed method can provide technical support for the monitoring and management of groundwater pollution in China. Copyright © 2015

New multiplex PCR methods for rapid screening of genetically modified organisms in foods

PubMed Central

Datukishvili, Nelly; Kutateladze, Tamara; Gabriadze, Inga; Bitskinashvili, Kakha; Vishnepolsky, Boris

2015-01-01

We present novel multiplex PCR methods for rapid and reliable screening of genetically modified organisms (GMOs). New designed PCR primers targeting four frequently used GMO specific sequences permitted identification of new DNA markers, in particular 141 bp fragment of cauliflower mosaic virus (CaMV) 35S promoter, 224 bp fragment of Agrobacterium tumefaciens nopaline synthase (NOS) terminator, 256 bp fragment of 5-enolppyruvylshikimate-phosphate synthase (epsps) gene and 258 bp fragment of Cry1Ab delta-endotoxin (cry1Ab) gene for GMO screening. The certified reference materials containing Roundup Ready soybean (RRS) and maize MON 810 were applied for the development and optimization of uniplex and multiplex PCR systems. Evaluation of amplification products by agarose gel electrophoresis using negative and positive controls confirmed high specificity and sensitivity at 0.1% GMO for both RRS and MON 810. The fourplex PCR was developed and optimized that allows simultaneous detection of three common transgenic elements, such as: CaMV 35S promoter, NOS terminator, epsps gene together with soybean-specific lectin gene. The triplex PCR developed enables simultaneous identification of transgenic elements, such as: 35S promoter and cry1Ab gene together with maize zein gene. The analysis of different processed foods demonstrated that multiplex PCR methods developed in this study are useful for accurate and fast screening of GM food products. PMID:26257724

New multiplex PCR methods for rapid screening of genetically modified organisms in foods.

PubMed

Datukishvili, Nelly; Kutateladze, Tamara; Gabriadze, Inga; Bitskinashvili, Kakha; Vishnepolsky, Boris

2015-01-01

We present novel multiplex PCR methods for rapid and reliable screening of genetically modified organisms (GMOs). New designed PCR primers targeting four frequently used GMO specific sequences permitted identification of new DNA markers, in particular 141 bp fragment of cauliflower mosaic virus (CaMV) 35S promoter, 224 bp fragment of Agrobacterium tumefaciens nopaline synthase (NOS) terminator, 256 bp fragment of 5-enolppyruvylshikimate-phosphate synthase (epsps) gene and 258 bp fragment of Cry1Ab delta-endotoxin (cry1Ab) gene for GMO screening. The certified reference materials containing Roundup Ready soybean (RRS) and maize MON 810 were applied for the development and optimization of uniplex and multiplex PCR systems. Evaluation of amplification products by agarose gel electrophoresis using negative and positive controls confirmed high specificity and sensitivity at 0.1% GMO for both RRS and MON 810. The fourplex PCR was developed and optimized that allows simultaneous detection of three common transgenic elements, such as: CaMV 35S promoter, NOS terminator, epsps gene together with soybean-specific lectin gene. The triplex PCR developed enables simultaneous identification of transgenic elements, such as: 35S promoter and cry1Ab gene together with maize zein gene. The analysis of different processed foods demonstrated that multiplex PCR methods developed in this study are useful for accurate and fast screening of GM food products.

Screening system and method of using same

DOEpatents

Jones, David A; Gresham, Christopher A; Basiliere, Marc L; Spates, James J; Rodacy, Philip J

2014-04-15

An integrated apparatus and method for screening an object for a target material is provided. The integrated apparatus comprises a housing and an integrated screener. The housing is positionable adjacent the object, and has a channel therethrough. The integrated screener is positionable in the housing, and comprises a fan, at least one filter, a heater and an analyzer. The fan is for drawing air carrying particles and vapor through the channel of the housing. The filter(s) is/are positionable in the channel of the housing for passage of the air therethrough. The filter(s) comprise(s) at least one metal foam having a plurality of pores therein for collecting and adsorbing a sample from the particles and vapor passing therethrough. The heater is for applying heat to the at least one metal foam whereby the collected sample is desorbed from the metal foam. The analyzer detects the target material from the desorbed sample.

Frailty screening methods for predicting outcome of a comprehensive geriatric assessment in elderly patients with cancer: a systematic review.

PubMed

Hamaker, Marije E; Jonker, Judith M; de Rooij, Sophia E; Vos, Alinda G; Smorenburg, Carolien H; van Munster, Barbara C

2012-10-01

Comprehensive geriatric assessment (CGA) is done to detect vulnerability in elderly patients with cancer so that treatment can be adjusted accordingly; however, this process is time-consuming and pre-screening is often used to identify fit patients who are able to receive standard treatment versus those in whom a full CGA should be done. We aimed to assess which of the frailty screening methods available show the best sensitivity and specificity for predicting the presence of impairments on CGA in elderly patients with cancer. We did a systematic search of Medline and Embase, and a hand-search of conference abstracts, for studies on the association between frailty screening outcome and results of CGA in elderly patients with cancer. Our search identified 4440 reports, of which 22 publications from 14 studies, were included in this Review. Seven different frailty screening methods were assessed. The median sensitivity and specificity of each screening method for predicting frailty on CGA were as follows: Vulnerable Elders Survey-13 (VES-13), 68% and 78%; Geriatric 8 (G8), 87% and 61%; Triage Risk Screening Tool (TRST 1+; patient considered frail if one or more impairments present), 92% and 47%, Groningen Frailty Index (GFI) 57% and 86%, Fried frailty criteria 31% and 91%, Barber 59% and 79%, and abbreviated CGA (aCGA) 51% and 97%. However, even in case of the highest sensitivity, the negative predictive value was only roughly 60%. G8 and TRST 1+ had the highest sensitivity for frailty, but both had poor specificity and negative predictive value. These findings suggest that, for now, it might be beneficial for all elderly patients with cancer to receive a complete geriatric assessment, since available frailty screening methods have insufficient discriminative power to select patients for further assessment. Copyright © 2012 Elsevier Ltd. All rights reserved.

A screening method to distinguish syndromic from sporadic spinal extradural arachnoid cyst.

PubMed

Ogura, Yoji; Yabuki, Shoji; Fujibayashi, Shunsuke; Okada, Eijiro; Iwanami, Akio; Watanabe, Kota; Nakamura, Masaya; Matsumoto, Morio; Ishii, Ken; Ikegawa, Shiro

2018-05-01

Spinal extradural arachnoid cyst (SEDAC) is a cystic lesion that protrudes into the epidural space from a small dural defect. Early diagnosis of SEDAC is important because its expansion causes neurological damage. Two types of SEDAC, syndromic and sporadic, are present. Syndromic SEDAC is inherited as a part of lymphedema-distichiasis syndrome caused by mutations in the FOXC2 gene; however, it is often mistaken as sporadic because of low penetrance. It is not reasonable to conduct a genetic testing for all SEDAC patients and their family members. The aim of this study is to establish an effective screening method to distinguish syndromic SEDAC from sporadic SEDAC. We performed a retrospective review of medical records and imaging studies of 29 subjects who were diagnosed with SEDAC. Clinical features, family history and magnetic resonance imaging (MRI) were analyzed. Mutations in FOXC2 were examined by Sanger-sequencing of the entire coding region of the genes. SEDAC having a mutation in FOXC2 gene was defined with syndromic SEDAC. Eleven subjects had a heterozygous mutation in FOXC2. They were all familial and hence syndromic SEDAC. Only one proband had known family history of SEDAC at diagnosis. MRI findings and physical examinations, especially eye and leg examinations, were quite useful to screen syndromic SEDAC. Physical examination often showed accompanying lymphedema and distichiasis in syndromic SEDAC. Syndromic SEDAC tended to have multiple cysts out of the thoracolumbar area. We established an effective screening method based on physical examinations and MRI findings. Copyright © 2018 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

Just-in-Time Compound Pooling Increases Primary Screening Capacity without Compromising Screening Quality.

PubMed

Elkin, L L; Harden, D G; Saldanha, S; Ferguson, H; Cheney, D L; Pieniazek, S N; Maloney, D P; Zewinski, J; O'Connell, J; Banks, M

2015-06-01

Compound pooling, or multiplexing more than one compound per well during primary high-throughput screening (HTS), is a controversial approach with a long history of limited success. Many issues with this approach likely arise from long-term storage of library plates containing complex mixtures of compounds at high concentrations. Due to the historical difficulties with using multiplexed library plates, primary HTS often uses a one-compound-one-well approach. However, as compound collections grow, innovative strategies are required to increase the capacity of primary screening campaigns. Toward this goal, we have developed a novel compound pooling method that increases screening capacity without compromising data quality. This method circumvents issues related to the long-term storage of complex compound mixtures by using acoustic dispensing to enable "just-in-time" compound pooling directly in the assay well immediately prior to assay. Using this method, we can pool two compounds per well, effectively doubling the capacity of a primary screen. Here, we present data from pilot studies using just-in-time pooling, as well as data from a large >2-million-compound screen using this approach. These data suggest that, for many targets, this method can be used to vastly increase screening capacity without significant reduction in the ability to detect screening hits. © 2015 Society for Laboratory Automation and Screening.

Screening DNA chip and event-specific multiplex PCR detection methods for biotech crops.

PubMed

Lee, Seong-Hun

2014-11-01

There are about 80 biotech crop events that have been approved by safety assessment in Korea. They have been controlled by genetically modified organism (GMO) and living modified organism (LMO) labeling systems. The DNA-based detection method has been used as an efficient scientific management tool. Recently, the multiplex polymerase chain reaction (PCR) and DNA chip have been developed as simultaneous detection methods for several biotech crops' events. The event-specific multiplex PCR method was developed to detect five biotech maize events: MIR604, Event 3272, LY 038, MON 88017 and DAS-59122-7. The specificity was confirmed and the sensitivity was 0.5%. The screening DNA chip was developed from four endogenous genes of soybean, maize, cotton and canola respectively along with two regulatory elements and seven genes: P35S, tNOS, pat, bar, epsps1, epsps2, pmi, cry1Ac and cry3B. The specificity was confirmed and the sensitivity was 0.5% for four crops' 12 events: one soybean, six maize, three cotton and two canola events. The multiplex PCR and DNA chip can be available for screening, gene-specific and event-specific analysis of biotech crops as efficient detection methods by saving on workload and time. © 2014 Society of Chemical Industry. © 2014 Society of Chemical Industry.

Comparison of real-time PCR with disk diffusion, agar screen and E-test methods for detection of methicillin-resistant Staphylococcus aureus.

PubMed

Shariati, Laleh; Validi, Majid; Tabatabaiefar, Mohammad Amin; Karimi, Ali; Nafisi, Mohammad Reza

2010-12-01

Methicillin-resistant Staphylococcus aureus (MRSA) is a nosocomial pathogen. Our main objective was to compare oxacillin disk test, oxacillin E-test, and oxacillin agar screen for detection of methicillin resistance in S. aureus, using real-time PCR for mecA as the "gold standard" comparison assay. 196 S. aureus isolates were identified out of 284 Staphylococcus isolates. These isolates were screened for MRSA with several methods: disk diffusion, agar screen (6.0 μg/ml), oxacillin E-test, and real-time PCR for detection of mecA gene. Of the 196 S. aureus isolates tested, 96 isolates (49%) were mecA-positive and 100 isolates (51%) mecA-negative. All methods tested had a statistically significant agreement with real-time PCR. E-test was 100% sensitive and specific for mecA presence. The sensitivity and specificity of oxacillin agar screen method were 98 and 99%, respectively and sensitivity and specificity of oxacillin disk diffusion method were 95 and 93%, respectively. In the present study, oxacillin E-test is proposed as the best phenotypic method. For economic reasons, the oxacillin agar screen method (6.0 μg/ml), which is suitable for the detection of MRSA, is recommended due to its accuracy and low cost.

An extension of the Coconut Cream Agar method to screen Penicillium citrinum isolates for citrinin production.

PubMed

Mohamed, S; Flint, S; Palmer, J; Fletcher, G C; Pitt, J I

2013-09-01

A simple and rapid screening method was developed for the detection of citrinin in fungal cultures using Coconut Cream Agar (CCA) described previously for detecting aflatoxin and ochratoxin A. Fifteen isolates of Penicillium citrinum were inoculated onto CCA and incubated at 25 and 30°C for 10 days. All isolates produced a distinct yellow green fluorescence on CCA when the reverse side of the agar plates were viewed under long wavelength UV light. Detection was optimal at 25°C after four to 5 days of incubation. Isolates positive by the CCA method also tested positive for citrinin production by the TLC agar plug method after growth on CCA, Czapek yeast extract agar and yeast extract sucrose agar. Control cultures were negative by both methods, indicating that the CCA Petri dish method was suitable for screening cultures for citrinin production. © 2013 The Society for Applied Microbiology.

Influence relevance voting: an accurate and interpretable virtual high throughput screening method.

PubMed

Swamidass, S Joshua; Azencott, Chloé-Agathe; Lin, Ting-Wan; Gramajo, Hugo; Tsai, Shiou-Chuan; Baldi, Pierre

2009-04-01

Given activity training data from high-throughput screening (HTS) experiments, virtual high-throughput screening (vHTS) methods aim to predict in silico the activity of untested chemicals. We present a novel method, the Influence Relevance Voter (IRV), specifically tailored for the vHTS task. The IRV is a low-parameter neural network which refines a k-nearest neighbor classifier by nonlinearly combining the influences of a chemical's neighbors in the training set. Influences are decomposed, also nonlinearly, into a relevance component and a vote component. The IRV is benchmarked using the data and rules of two large, open, competitions, and its performance compared to the performance of other participating methods, as well as of an in-house support vector machine (SVM) method. On these benchmark data sets, IRV achieves state-of-the-art results, comparable to the SVM in one case, and significantly better than the SVM in the other, retrieving three times as many actives in the top 1% of its prediction-sorted list. The IRV presents several other important advantages over SVMs and other methods: (1) the output predictions have a probabilistic semantic; (2) the underlying inferences are interpretable; (3) the training time is very short, on the order of minutes even for very large data sets; (4) the risk of overfitting is minimal, due to the small number of free parameters; and (5) additional information can easily be incorporated into the IRV architecture. Combined with its performance, these qualities make the IRV particularly well suited for vHTS.

School Locations and Traffic Emissions — Environmental (In)Justice Findings Using a New Screening Method

PubMed Central

Gaffron, Philine; Niemeier, Deb

2015-01-01

It has been shown that the location of schools near heavily trafficked roads can have detrimental effects on the health of children attending those schools. It is therefore desirable to screen both existing school locations and potential new school sites to assess either the need for remedial measures or suitability for the intended use. Current screening tools and public guidance on school siting are either too coarse in their spatial resolution for assessing individual sites or are highly resource intensive in their execution (e.g., through dispersion modeling). We propose a new method to help bridge the gap between these two approaches. Using this method, we also examine the public K-12 schools in the Sacramento Area Council of Governments Region, California (USA) from an environmental justice perspective. We find that PM2.5 emissions from road traffic affecting a school site are significantly positively correlated with the following metrics: percent share of Black, Hispanic and multi-ethnic students, percent share of students eligible for subsidized meals. The emissions metric correlates negatively with the schools’ Academic Performance Index, the share of White students and average parental education levels. Our PM2.5 metric also correlates with the traffic related, census tract level screening indicators from the California Communities Environmental Health Screening Tool and the tool’s tract level rate of asthma related emergency department visits. PMID:25679341

Flexible methods for segmentation evaluation: results from CT-based luggage screening.

PubMed

Karimi, Seemeen; Jiang, Xiaoqian; Cosman, Pamela; Martz, Harry

2014-01-01

Imaging systems used in aviation security include segmentation algorithms in an automatic threat recognition pipeline. The segmentation algorithms evolve in response to emerging threats and changing performance requirements. Analysis of segmentation algorithms' behavior, including the nature of errors and feature recovery, facilitates their development. However, evaluation methods from the literature provide limited characterization of the segmentation algorithms. To develop segmentation evaluation methods that measure systematic errors such as oversegmentation and undersegmentation, outliers, and overall errors. The methods must measure feature recovery and allow us to prioritize segments. We developed two complementary evaluation methods using statistical techniques and information theory. We also created a semi-automatic method to define ground truth from 3D images. We applied our methods to evaluate five segmentation algorithms developed for CT luggage screening. We validated our methods with synthetic problems and an observer evaluation. Both methods selected the same best segmentation algorithm. Human evaluation confirmed the findings. The measurement of systematic errors and prioritization helped in understanding the behavior of each segmentation algorithm. Our evaluation methods allow us to measure and explain the accuracy of segmentation algorithms.

Mammogram screening in Chile: Using mixed methods to implement health policy planning at the primary care level

PubMed Central

Puschel, Klaus; Thompson, Beti

2011-01-01

Summary Breast cancer has the highest incidence of all cancers among women in Chile. In 2005, a national health program progressively introduced free mammography screening for women aged 50 and older; however, three years later the rates of compliance with mammographic screening was only 12% in Santiago, the capital city of Chile. This implementation article combines the findings of two previous studies that applied qualitative and quantitative methods to improve mammography screening in an area of Santiago. Socio-cultural and accessibility factors were identified as barriers and facilitators during the qualitative phase of the study and then applied to the design of a quantitative randomized clinical trial. After six months of intervention, 6% of women in the standard care group, 51.8% in the low intensity intervention group, and 70.1% in the high intensity intervention group had undergone a screening mammogram. This review discusses how the utilization of mixed methods research can contribute to the improvement of the implementation of health policies in local communities. PMID:21334897

Development of a small-molecule screening method for inhibitors of cellular response to myostatin and activin A.

PubMed

Cash, Jennifer N; Angerman, Elizabeth B; Kirby, R Jason; Merck, Lisa; Seibel, William L; Wortman, Matthew D; Papoian, Ruben; Nelson, Sandra; Thompson, Thomas B

2013-08-01

Myostatin, a member of the transforming growth factor (TGF)-β family of secreted ligands, is a strong negative regulator of muscle growth. As such, therapeutic inhibitors of myostatin are actively being investigated for their potential in the treatment of muscle-wasting diseases such as muscular dystrophy and sarcopenia. Here, we sought to develop a high-throughput screening (HTS) method for small-molecule inhibitors that target myostatin. We created a HEK293 stable cell line that expresses the (CAGA)12-luciferase reporter construct and robustly responds to signaling of certain classes of TGF-β family ligands. After optimization and miniaturization of the assay to a 384-well format, we successfully screened a library of compounds for inhibition of myostatin and the closely related activin A. Selection of some of the tested compounds was directed by in silico screening against myostatin, which led to an enrichment of target hits as compared with random selection. Altogether, we present an HTS method that will be useful for screening potential inhibitors of not only myostatin but also many other ligands of the TGF-β family.

Statistical optimization of recycled-paper enzymatic hydrolysis for simultaneous saccharification and fermentation via central composite design.

PubMed

Liu, Qing; Cheng, Ke-ke; Zhang, Jian-an; Li, Jin-ping; Wang, Ge-hua

2010-01-01

A central composite design of the response surface methodology (RSM) was employed to study the effects of temperature, enzyme concentration, and stirring rate on recycled-paper enzymatic hydrolysis. Among the three variables, temperature and enzyme concentration significantly affected the conversion efficiency of substrate, whereas stirring rate was not effective. A quadratic polynomial equation was obtained for enzymatic hydrolysis by multiple regression analysis using RSM. The results of validation experiments were coincident with the predicted model. The optimum conditions for enzymatic hydrolysis were temperature, enzyme concentration, and stirring rate of 43.1 degrees C, 20 FPU g(-1) substrate, and 145 rpm, respectively. In the subsequent simultaneous saccharification and fermentation (SSF) experiment under the optimum conditions, the highest 28.7 g ethanol l(-1) was reached in the fed-batch SSF when 5% (w/v) substrate concentration was used initially, and another 5% added after 12 h fermentation. This ethanol output corresponded to 77.7% of the theoretical yield based on the glucose content in the raw material.

Simultaneous saccharification and aerobic fermentation of high titer cellulosic citric acid by filamentous fungus Aspergillus niger.

PubMed

Hou, Weiliang; Bao, Jie

2018-04-01

Simultaneous saccharification and fermentation (SSF) is the most efficient operation in biorefining conversion, but aerobic SSF under high solids loading significantly faces the serious oxygen transfer limitation. This study took the first insight into an aerobic SSF by high oxygen demanding filamentous fungi in highly viscous lignocellulose hydrolysate. The results show that oxygen requirement in the aerobic SSF by Aspergillus niger was well satisfied for production of cellulosic citric acid. The record high citric acid titer of 136.3 g/L and the overall conversion yield of 74.9% of cellulose were obtained by the aerobic SSF. The advantage of SSF to the separate hydrolysis and fermentation (SHF) on citric acid fermentation was compared based on the rigorous Aspen Plus modeling. The techno-economic analysis indicates that the minimum citric acid selling price (MCSP) of $0.603 per kilogram by SSF was highly competitive with the commercial citric acid from starch feedstock. Copyright © 2018 Elsevier Ltd. All rights reserved.

State of the art in the validation of screening methods for the control of antibiotic residues: is there a need for further development?

PubMed

Gaudin, Valérie

2017-09-01

Screening methods are used as a first-line approach to detect the presence of antibiotic residues in food of animal origin. The validation process guarantees that the method is fit-for-purpose, suited to regulatory requirements, and provides evidence of its performance. This article is focused on intra-laboratory validation. The first step in validation is characterisation of performance, and the second step is the validation itself with regard to pre-established criteria. The validation approaches can be absolute (a single method) or relative (comparison of methods), overall (combination of several characteristics in one) or criterion-by-criterion. Various approaches to validation, in the form of regulations, guidelines or standards, are presented and discussed to draw conclusions on their potential application for different residue screening methods, and to determine whether or not they reach the same conclusions. The approach by comparison of methods is not suitable for screening methods for antibiotic residues. The overall approaches, such as probability of detection (POD) and accuracy profile, are increasingly used in other fields of application. They may be of interest for screening methods for antibiotic residues. Finally, the criterion-by-criterion approach (Decision 2002/657/EC and of European guideline for the validation of screening methods), usually applied to the screening methods for antibiotic residues, introduced a major characteristic and an improvement in the validation, i.e. the detection capability (CCβ). In conclusion, screening methods are constantly evolving, thanks to the development of new biosensors or liquid chromatography coupled to tandem-mass spectrometry (LC-MS/MS) methods. There have been clear changes in validation approaches these last 20 years. Continued progress is required and perspectives for future development of guidelines, regulations and standards for validation are presented here.

Comparison of the Modified-Hodge test, Carba NP test, and carbapenem inactivation method as screening methods for carbapenemase-producing Enterobacteriaceae.

PubMed

Yamada, Kageto; Kashiwa, Machiko; Arai, Katsumi; Nagano, Noriyuki; Saito, Ryoichi

2016-09-01

We compared three screening methods for carbapenemase-producing Enterobacteriaceae. While the Modified-Hodge test and Carba NP test produced false-negative results for OXA-48-like and mucoid NDM producers, the carbapenem inactivation method (CIM) showed positive results for these isolates. Although the CIM required cultivation time, it is well suited for general clinical laboratories. Copyright © 2016 Elsevier B.V. All rights reserved.

Microbial screening for quinolones residues in cow milk by bio-optical method.

PubMed

Appicciafuoco, Brunella; Dragone, Roberto; Frazzoli, Chiara; Bolzoni, Giuseppe; Mantovani, Alberto; Ferrini, Anna Maria

2015-03-15

The use of antibiotics on lactating cows should be monitored for the possible risk of milk contamination with residues. Accordingly, Maximum Residue Levels (MRLs) are established by the European Commission to guarantee consumers safety. As pointed out by Dec 2002/657/EC, screening is the first step in the strategy for antibiotic residue control, thus playing a key role in the whole control procedure. However, current routine screening methods applied in milk chain still fail to detect residues of quinolones at concentrations of interest. This paper reports the findings of a new bio-optical method for the screening of quinolones residues in bovine milk, based on E. coli ATCC 11303 growth inhibition. The effect of blank and spiked cow milk samples (aliquots equivalents to 0.8%, v/v) is evaluated in Mueller Hinton Broth (MHb) and MHb enriched with MgSO4 2% (MHb-Mg) inoculated with the test strain at the concentration of 10(4)CFU/mL. The presence of quinolones inhibits the cellular growth in MHb, while this effect is neutralized in MHb-Mg allowing both detection and presumptive identification of quinolones. Growth of the test strain is monitored at 37 °C in a Bioscreen C automated system, and Optical Density (OD) at 600 nm is recorded every 10 min after shaking for 10s. Growth curves (OD vs. time) of E. coli ATCC 11303 are assessed in milk samples, with and without quinolones, and their differences in terms of ΔOD (ΔOD600nm=ODMHb-Mg-ODMHb) are calculated. The presence of quinolones is detected by the cellular growth inhibition (OD vs time, none increase in the value OD) and presumptively identified through the increase of the slope of ΔOD600nm curve (ΔOD vs. time), after about 3h of incubation. The detection limit for ciprofloxacin and enrofloxacin is at the level of MRL, for marbofloxacin is at 2-fold the MRL whereas for danofloxacin is at 4-fold the MRL. Although the sensitivity of the method could be further improved and the procedure automated, it is a

Precision breeding for RNAi suppression of a major 4-coumarate:coenzyme A ligase gene improves cell wall saccharification from field grown sugarcane.

PubMed

Jung, Je Hyeong; Kannan, Baskaran; Dermawan, Hugo; Moxley, Geoffrey W; Altpeter, Fredy

2016-11-01

Sugarcane (Saccharum spp. hybrids) is a major feedstock for commercial bioethanol production. The recent integration of conversion technologies that utilize lignocellulosic sugarcane residues as well as sucrose from stem internodes has elevated bioethanol yields. RNAi suppression of lignin biosynthetic enzymes is a successful strategy to improve the saccharification of lignocellulosic biomass. 4-coumarate:coenzyme A ligase (4CL) is a key enzyme in the biosynthesis of phenylpropanoid metabolites, such as lignin and flavonoids. Identifying a major 4CL involved in lignin biosynthesis among multiple isoforms with functional divergence is key to manipulate lignin biosynthesis. In this study, two full length 4CL genes (Sh4CL1 and Sh4CL2) were isolated and characterized in sugarcane. Phylogenetic, expression and RNA interference (RNAi) analysis confirmed that Sh4CL1 is a major lignin biosynthetic gene. An intragenic precision breeding strategy may facilitate the regulatory approval of the genetically improved events and was used for RNAi suppression of Sh4CL1. Both, the RNAi inducing cassette and the expression cassette for the mutated ALS selection marker consisted entirely of DNA sequences from sugarcane or the sexually compatible species Sorghum bicolor. Field grown sugarcane with intragenic RNAi suppression of Sh4CL1 resulted in reduction of the total lignin content by up to 16.5 % along with altered monolignol ratios without reduction in biomass yield. Mature, field grown, intragenic sugarcane events displayed 52-76 % improved saccharification efficiency of lignocellulosic biomass compared to wild type (WT) controls. This demonstrates for the first time that an intragenic approach can add significant value to lignocellulosic feedstocks for biofuel and biochemical production.

Screening and identification of radical scavengers from Neo-Taraxacum siphonanthum by online rapid screening method and nuclear magnetic resonance experiments.

PubMed

Shi, Shu Yun; Zhang, Yu Ping; Zhou, Hong Hao; Huang, Ke Long; Jiang, Xin Yu

2010-01-01

An online rapid screening method, the high-performance liquid chromatography (HPLC)-diode array detector (DAD)-radical scavenging detection (RSD)-electrospray ionization (ESI)-mass spectroscopy (MS)/MS system, was developed for the screening and identification of radical scavengers from Neo-Taraxacum siphonanthum, a new species found in China in 1989. For further characterization, the target compounds were isolated by silica column chromatography, preparative high-performance liquid chromatography (HPLC), HSCCC, and Sephadex LH-20 column chromatography and elucidated on the basis of ultraviolet (UV), ESI-MS/MS, and nuclear magnetic resonance (NMR) spectroscopy, as well as the chemical analysis. Eighteen antioxidative polyphenols (5 caffeic acid derivatives and 13 flavonoid derivatives) were characterized from Neo-T. siphonanthum. The distribution of all compounds was discussed in a chemosystematic context, which suggested that the genera Neo-Taraxacum and Taraxacum might relate chemosystematically.

EVALUATION OF A FLUOROMETRIC SCREENING METHOD FOR PREDICTING TOTAL PAH CONCENTRATIONS IN CONTAMINATED SEDIMENTS

EPA Science Inventory

A flurorometric screening method was used to estimate total polycyclic aromatic hydrocarbon concentrations in sediments collected from the St. Louis River Area of Concern in northeastern Minnesota. Sediments were collected as part of a Regional Environmental Monitoring and Asses...

Prenatal Cell-Free DNA Screening

MedlinePlus

Prenatal cell-free DNA screening Overview Prenatal cell-free DNA (cfDNA) screening, also known as noninvasive prenatal screening, is a method to screen ... in a developing baby. During prenatal cell-free DNA screening, DNA from the mother and fetus is ...

Large-scale systematic analysis of 2D fingerprint methods and parameters to improve virtual screening enrichments.

PubMed

Sastry, Madhavi; Lowrie, Jeffrey F; Dixon, Steven L; Sherman, Woody

2010-05-24

A systematic virtual screening study on 11 pharmaceutically relevant targets has been conducted to investigate the interrelation between 8 two-dimensional (2D) fingerprinting methods, 13 atom-typing schemes, 13 bit scaling rules, and 12 similarity metrics using the new cheminformatics package Canvas. In total, 157 872 virtual screens were performed to assess the ability of each combination of parameters to identify actives in a database screen. In general, fingerprint methods, such as MOLPRINT2D, Radial, and Dendritic that encode information about local environment beyond simple linear paths outperformed other fingerprint methods. Atom-typing schemes with more specific information, such as Daylight, Mol2, and Carhart were generally superior to more generic atom-typing schemes. Enrichment factors across all targets were improved considerably with the best settings, although no single set of parameters performed optimally on all targets. The size of the addressable bit space for the fingerprints was also explored, and it was found to have a substantial impact on enrichments. Small bit spaces, such as 1024, resulted in many collisions and in a significant degradation in enrichments compared to larger bit spaces that avoid collisions.

Utilization of breast cancer screening methods in a developing nation: results from a nationally representative sample of Malaysian households.

PubMed

Dunn, Richard A; Tan, Andrew K G

2011-01-01

As is the case in many developing nations, previous studies of breast cancer screening behavior in Malaysia have used relatively small samples that are not nationally representative, thereby limiting the generalizability of results. Therefore, this study uses nationally representative data from the Malaysia Non-Communicable Disease Surveillance-1 to investigate the role of socio-economic status on breast cancer screening behavior in Malaysia, particularly differences in screening behaviour between ethnic groups. The decisions of 816 women above age 40 in Malaysia to screen for breast cancer using mammography, clinical breast exams (CBE), and breast self-exams (BSE) are modeled using logistic regression. Results indicate that after adjusting for differences in age, education, household income, marital status, and residential location, Malay women are less likely than Chinese and Indian women to utilize mammography, but more likely to perform BSE. Education level and urban residence are positively associated with utilization of each method, but these relationships vary across ethnicity. Higher education levels are strongly related to using each screening method among Chinese women, but have no statistically significant relationship to screening among Malays. © 2011 Wiley Periodicals, Inc.

Pathophysiology, risk factors, and screening methods for prediabetes in women with polycystic ovary syndrome

PubMed Central

Gourgari, Evgenia; Spanakis, Elias; Dobs, Adrian Sandra

2016-01-01

Polycystic ovary syndrome (PCOS) is a syndrome associated with insulin resistance (IR), obesity, infertility, and increased cardiometabolic risk. This is a descriptive review of several mechanisms that can explain the IR among women with PCOS, other risk factors for the development of diabetes, and the screening methods used for the detection of glucose intolerance in women with PCOS. Few mechanisms can explain IR in women with PCOS such as obesity, insulin receptor signaling defects, and inhibition of insulin-mediated glucose uptake in adipocytes. Women with PCOS have additional risk factors for the development of glucose intolerance such as family history of diabetes, use of oral contraceptives, anovulation, and age. The Androgen Society in 2007 and the Endocrine Society in 2013 recommended using oral glucose tolerance test as a screening tool for abnormal glucose tolerance in all women with PCOS. The approach to detection of glucose intolerance among women with PCOS varies among health care providers. Large prospective studies are still needed for the development of guidelines with strong evidence. When assessing risk of future diabetes in women with PCOS, it is important to take into account the method used for screening as well as other risk factors that these women might have. PMID:27570464

Pathophysiology, risk factors, and screening methods for prediabetes in women with polycystic ovary syndrome.

PubMed

Gourgari, Evgenia; Spanakis, Elias; Dobs, Adrian Sandra

2016-01-01

Polycystic ovary syndrome (PCOS) is a syndrome associated with insulin resistance (IR), obesity, infertility, and increased cardiometabolic risk. This is a descriptive review of several mechanisms that can explain the IR among women with PCOS, other risk factors for the development of diabetes, and the screening methods used for the detection of glucose intolerance in women with PCOS. Few mechanisms can explain IR in women with PCOS such as obesity, insulin receptor signaling defects, and inhibition of insulin-mediated glucose uptake in adipocytes. Women with PCOS have additional risk factors for the development of glucose intolerance such as family history of diabetes, use of oral contraceptives, anovulation, and age. The Androgen Society in 2007 and the Endocrine Society in 2013 recommended using oral glucose tolerance test as a screening tool for abnormal glucose tolerance in all women with PCOS. The approach to detection of glucose intolerance among women with PCOS varies among health care providers. Large prospective studies are still needed for the development of guidelines with strong evidence. When assessing risk of future diabetes in women with PCOS, it is important to take into account the method used for screening as well as other risk factors that these women might have.

OsCESA9 conserved-site mutation leads to largely enhanced plant lodging resistance and biomass enzymatic saccharification by reducing cellulose DP and crystallinity in rice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Fengcheng; Xie, Guosheng; Huang, Jiangfeng

Genetic modification of plant cell walls has been posed to reduce lignocellulose recalcitrance for enhancing biomass saccharification. Several dozen CESA mutants have been reported since cellulose synthase (CESA) gene was first identified, but almost all mutants exhibit the defective phenotypes in plant growth and development. Here, the rice (Oryza sativa) Osfc16 mutant with substitutions (W481C, P482S) at P-CR conserved site in CESA9 shows a slightly affected plant growth and higher biomass yield by 25%–41% compared with wild type (Nipponbare, a japonica variety). Chemical and ultrastructural analyses indicate that Osfc16 has a significantly reduced cellulose crystallinity (CrI) and thinner secondary cellmore » walls compared with wild type. CESA co-IP detection, together with implementations of a proteasome inhibitor (MG132) and two distinct cellulose inhibitors (Calcofluor, CGA), shows that CESA9 mutation could affect integrity of CESA4/7/9 complexes, which may lead to rapid CESA proteasome degradation for low-DP cellulose biosynthesis. These may reduce cellulose CrI, which improves plant lodging resistance, a major and integrated agronomic trait on plant growth and grain production, and enhances biomass enzymatic saccharification by up to 2.3-fold and ethanol productivity by 34%–42%. Our study has for the first time reported a direct modification for the low-DP cellulose production that has broad applications in biomass industries.« less

OsCESA9 conserved-site mutation leads to largely enhanced plant lodging resistance and biomass enzymatic saccharification by reducing cellulose DP and crystallinity in rice

DOE PAGES

Li, Fengcheng; Xie, Guosheng; Huang, Jiangfeng; ...

2017-03-15

Genetic modification of plant cell walls has been posed to reduce lignocellulose recalcitrance for enhancing biomass saccharification. Several dozen CESA mutants have been reported since cellulose synthase (CESA) gene was first identified, but almost all mutants exhibit the defective phenotypes in plant growth and development. Here, the rice (Oryza sativa) Osfc16 mutant with substitutions (W481C, P482S) at P-CR conserved site in CESA9 shows a slightly affected plant growth and higher biomass yield by 25%–41% compared with wild type (Nipponbare, a japonica variety). Chemical and ultrastructural analyses indicate that Osfc16 has a significantly reduced cellulose crystallinity (CrI) and thinner secondary cellmore » walls compared with wild type. CESA co-IP detection, together with implementations of a proteasome inhibitor (MG132) and two distinct cellulose inhibitors (Calcofluor, CGA), shows that CESA9 mutation could affect integrity of CESA4/7/9 complexes, which may lead to rapid CESA proteasome degradation for low-DP cellulose biosynthesis. These may reduce cellulose CrI, which improves plant lodging resistance, a major and integrated agronomic trait on plant growth and grain production, and enhances biomass enzymatic saccharification by up to 2.3-fold and ethanol productivity by 34%–42%. Our study has for the first time reported a direct modification for the low-DP cellulose production that has broad applications in biomass industries.« less

FMM-Yukawa: An adaptive fast multipole method for screened Coulomb interactions

NASA Astrophysics Data System (ADS)

Huang, Jingfang; Jia, Jun; Zhang, Bo

2009-11-01

A Fortran program package is introduced for the rapid evaluation of the screened Coulomb interactions of N particles in three dimensions. The method utilizes an adaptive oct-tree structure, and is based on the new version of fast multipole method in which the exponential expansions are used to diagonalize the multipole-to-local translations. The program and its full description, as well as several closely related packages are also available at http://www.fastmultipole.org/. This paper is a brief review of the program and its performance. Catalogue identifier: AEEQ_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEEQ_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GPL 2.0 No. of lines in distributed program, including test data, etc.: 12 385 No. of bytes in distributed program, including test data, etc.: 79 222 Distribution format: tar.gz Programming language: Fortran77 and Fortran90 Computer: Any Operating system: Any RAM: Depends on the number of particles, their distribution, and the adaptive tree structure Classification: 4.8, 4.12 Nature of problem: To evaluate the screened Coulomb potential and force field of N charged particles, and to evaluate a convolution type integral where the Green's function is the fundamental solution of the modified Helmholtz equation. Solution method: An adaptive oct-tree is generated, and a new version of fast multipole method is applied in which the "multipole-to-local" translation operator is diagonalized. Restrictions: Only three and six significant digits accuracy options are provided in this version. Unusual features: Most of the codes are written in

Methods for Effective Virtual Screening and Scaffold-Hopping in Chemical Compounds

DTIC Science & Technology

2007-04-04

contains color images. 14. ABSTRACT 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 12 19a...Opterons with 4 GB of memory . We used the descriptor- spaces GF, ECZ3, and ErG (described in Section 4) for the evaluating the methods introduced in...screening: Use of data fusion and machine learning to enchance the effectiveness of sim- ilarity searching. J. Chem. Info. Model., (46):462–470, 2006. [18] J

Screening of groundwater remedial alternatives for brownfield sites: a comprehensive method integrated MCDA with numerical simulation.

PubMed

Li, Wei; Zhang, Min; Wang, Mingyu; Han, Zhantao; Liu, Jiankai; Chen, Zhezhou; Liu, Bo; Yan, Yan; Liu, Zhu

2018-06-01

Brownfield sites pollution and remediation is an urgent environmental issue worldwide. The screening and assessment of remedial alternatives is especially complex owing to its multiple criteria that involves technique, economy, and policy. To help the decision-makers selecting the remedial alternatives efficiently, the criteria framework conducted by the U.S. EPA is improved and a comprehensive method that integrates multiple criteria decision analysis (MCDA) with numerical simulation is conducted in this paper. The criteria framework is modified and classified into three categories: qualitative, semi-quantitative, and quantitative criteria, MCDA method, AHP-PROMETHEE (analytical hierarchy process-preference ranking organization method for enrichment evaluation) is used to determine the priority ranking of the remedial alternatives and the solute transport simulation is conducted to assess the remedial efficiency. A case study was present to demonstrate the screening method in a brownfield site in Cangzhou, northern China. The results show that the systematic method provides a reliable way to quantify the priority of the remedial alternatives.

Incorporating Virtual Reactions into a Logic-based Ligand-based Virtual Screening Method to Discover New Leads

PubMed Central

Reynolds, Christopher R; Muggleton, Stephen H; Sternberg, Michael J E

2015-01-01

The use of virtual screening has become increasingly central to the drug development pipeline, with ligand-based virtual screening used to screen databases of compounds to predict their bioactivity against a target. These databases can only represent a small fraction of chemical space, and this paper describes a method of exploring synthetic space by applying virtual reactions to promising compounds within a database, and generating focussed libraries of predicted derivatives. A ligand-based virtual screening tool Investigational Novel Drug Discovery by Example (INDDEx) is used as the basis for a system of virtual reactions. The use of virtual reactions is estimated to open up a potential space of 1.21×1012 potential molecules. A de novo design algorithm known as Partial Logical-Rule Reactant Selection (PLoRRS) is introduced and incorporated into the INDDEx methodology. PLoRRS uses logical rules from the INDDEx model to select reactants for the de novo generation of potentially active products. The PLoRRS method is found to increase significantly the likelihood of retrieving molecules similar to known actives with a p-value of 0.016. Case studies demonstrate that the virtual reactions produce molecules highly similar to known actives, including known blockbuster drugs. PMID:26583052

From Classical to High Throughput Screening Methods for Feruloyl Esterases: A Review.

PubMed

Ramírez-Velasco, Lorena; Armendáriz-Ruiz, Mariana; Rodríguez-González, Jorge Alberto; Müller-Santos, Marcelo; Asaff-Torres, Ali; Mateos-Díaz, Juan Carlos

2016-01-01

Feruloyl esterases (FAEs) are a diverse group of hydrolases widely distributed in plants and microorganisms which catalyzes the cleavage and formation of ester bonds between plant cell wall polysaccharides and phenolic acids. FAEs have gained importance in biofuel, medicine and food industries due to their capability of acting on a large range of substrates for cleaving ester bonds and synthesizing highadded value molecules through esterification and transesterification reactions. During the past two decades extensive studies have been carried out on the production, characterization and classification of FAEs, however only a few reports of suitable High Throughput Screening assays for this kind of enzymes have been reported. This review is focused on a concise but complete revision of classical to High Throughput Screening methods for FAEs, highlighting its advantages and disadvantages, and finally suggesting future perspectives for this important research field.

Evaluation of Nurses' Acceptance of Screen Display Methods with Temporarily Non-Display for Privacy Protection.

PubMed

Niimi, Yukari; Ota, Katsumasa; Ikegami, Chikako

2018-01-01

The purpose of this study was to explore nurses' acceptance of a screen display method that temporarily hides patient information for privacy protection. Using a questionnaire, we asked nurses to evaluate the display method from the viewpoints of safety and efficiency with respect to 22 personal information items. The nurses were favorably interested in introducing the display method into their hospital system; however, their acceptance varied.

A Comparison of Protein Kinases Inhibitor Screening Methods Using Both Enzymatic Activity and Binding Affinity Determination

PubMed Central

Rudolf, Amalie Frederikke; Skovgaard, Tine; Knapp, Stefan; Jensen, Lars Juhl; Berthelsen, Jens

2014-01-01

Binding assays are increasingly used as a screening method for protein kinase inhibitors; however, as yet only a weak correlation with enzymatic activity-based assays has been demonstrated. We show that the correlation between the two types of assays can be improved using more precise screening conditions. Furthermore a marked improvement in the correlation was found by using kinase constructs containing the catalytic domain in presence of additional domains or subunits. PMID:24915177

Flexible methods for segmentation evaluation: Results from CT-based luggage screening

PubMed Central

Karimi, Seemeen; Jiang, Xiaoqian; Cosman, Pamela; Martz, Harry

2017-01-01

BACKGROUND Imaging systems used in aviation security include segmentation algorithms in an automatic threat recognition pipeline. The segmentation algorithms evolve in response to emerging threats and changing performance requirements. Analysis of segmentation algorithms’ behavior, including the nature of errors and feature recovery, facilitates their development. However, evaluation methods from the literature provide limited characterization of the segmentation algorithms. OBJECTIVE To develop segmentation evaluation methods that measure systematic errors such as oversegmentation and undersegmentation, outliers, and overall errors. The methods must measure feature recovery and allow us to prioritize segments. METHODS We developed two complementary evaluation methods using statistical techniques and information theory. We also created a semi-automatic method to define ground truth from 3D images. We applied our methods to evaluate five segmentation algorithms developed for CT luggage screening. We validated our methods with synthetic problems and an observer evaluation. RESULTS Both methods selected the same best segmentation algorithm. Human evaluation confirmed the findings. The measurement of systematic errors and prioritization helped in understanding the behavior of each segmentation algorithm. CONCLUSIONS Our evaluation methods allow us to measure and explain the accuracy of segmentation algorithms. PMID:24699346

A marine bacterial adhesion microplate test using the DAPI fluorescent dye: a new method to screen antifouling agents.

PubMed

Leroy, C; Delbarre-Ladrat, C; Ghillebaert, F; Rochet, M J; Compère, C; Combes, D

2007-04-01

To develop a method to screen antifouling agents against marine bacterial adhesion as a sensitive, rapid and quantitative microplate fluorescent test. Our experimental method is based on a natural biofilm formed by mono-incubation of the marine bacterium Pseudoalteromonas sp. D41 in sterile natural sea water in a 96-well polystyrene microplate. The 4'6-diamidino-2-phenylindole dye was used to quantify adhered bacteria in each well. The total measured fluorescence in the wells was correlated with the amount of bacteria showing a detection limit of one bacterium per 5 microm(2) and quantifying 2 x 10(7) to 2 x 10(8) bacteria adhered per cm(2). The antifouling properties of three commercial surface-active agents and chlorine were tested by this method in the prevention of adhesion and also in the detachment of already adhered bacteria. The marine bacterial adhesion inhibition rate depending on the agent concentration showed a sigmoid shaped dose-response curve. This test is well adapted for a rapid and quantitative first screening of antifouling agents directly in seawater in the early steps of marine biofilm formation. In contrast to the usual screenings of antifouling products which detect a bactericidal activity, this test is more appropriate to screen antifouling agents for bacterial adhesion removal or bacterial adhesion inhibition activities. This screening test focuses on the antifouling properties of the products, especially the initial steps of marine biofilm formation.

Hog Charm II tetracycline test screening results compared with a liquid chromatography tandem mass spectrometry 10-μg/kg method.

PubMed

Salter, Robert; Holmes, Steven; Legg, David; Coble, Joel; George, Bruce

2012-02-01

Pork tissue samples that tested positive and negative by the Charm II tetracycline test screening method in the slaughter plant laboratory were tested with the modified AOAC International liquid chromatography tandem mass spectrometry (LC-MS-MS) method 995.09 to determine the predictive value of the screening method at detecting total tetracyclines at 10 μg/kg of tissue, in compliance with Russian import regulations. There were 218 presumptive-positive tetracycline samples of 4,195 randomly tested hogs. Of these screening test positive samples, 83% (182) were positive, >10 μg/kg by LC-MS-MS; 12.8% (28) were false violative, greater than limit of detection (LOD) but <10 μg/kg; and 4.2% (8) were not detected at the LC-MS-MS LOD. The 36 false-violative and not-detected samples represent 1% of the total samples screened. Twenty-seven of 30 randomly selected tetracycline screening negative samples tested below the LC-MS-MS LOD, and 3 samples tested <3 μg/kg chlortetracycline. Results indicate that the Charm II tetracycline test is effective at predicting hogs containing >10 μg/kg total tetracyclines in compliance with Russian import regulations.

Application of a screening method in assessing occupational safety and health of computer workstations.

PubMed

Niskanen, Toivo; Lehtelä, Jouni; Länsikallio, Riina

2014-01-01

Employers and workers need concrete guidance to plan and implement changes in the ergonomics of computer workstations. The Näppärä method is a screening tool for identifying problems requiring further assessment and corrective actions. The aim of this study was to assess the work of occupational safety and health (OSH) government inspectors who used Näppärä as part of their OSH enforcement inspections (430 assessments) related to computer work. The modifications in workstation ergonomics involved mainly adjustments to the screen, mouse, keyboard, forearm supports, and chair. One output of the assessment is an index indicating the percentage of compliance items. This method can be considered as exposure assessment and ergonomics intervention used as a benchmark for the level of ergonomics. Future research can examine whether the effectiveness of participatory ergonomics interventions should be investigated with Näppärä.

Intelligent screening of electrofusion-polyethylene joints based on a thermal NDT method

NASA Astrophysics Data System (ADS)

Doaei, Marjan; Tavallali, M. Sadegh

2018-05-01

The combinations of infrared thermal images and artificial intelligence methods have opened new avenues for pushing the boundaries of available testing methods. Hence, in the current study, a novel thermal non-destructive testing method for polyethylene electrofusion joints was combined with k-means clustering algorithms as an intelligent screening tool. The experiments focused on ovality of pipes in the coupler, as well as misalignment of pipes-couplers in 25 mm diameter joints. The temperature responses of each joint to an internal heat pulse were recorded by an IR thermal camera, and further processed to identify the faulty joints. The results represented clustering accuracy of 92%, as well as more than 90% abnormality detection capabilities.

Kinetic modeling of simultaneous saccharification and fermentation of corn starch for ethanol production.

PubMed

Białas, Wojciech; Czerniak, Adrian; Szymanowska-Powałowska, Daria

2014-01-01

Fuel ethanol production, using a simultaneous saccharification and fermentation process (SSF) of native starch from corn flour, has been performed using Saccharomyces cerevisiae and a granular starch hydrolyzing enzyme. The quantitative effects of mash concentration, enzyme dose and pH were investigated with the use of a Box-Wilson central composite design protocol. Proceeding from results obtained in optimal fermentation conditions, a kinetics model relating the utilization rates of starch and glucose as well as the production rates of ethanol and biomass was tested. Moreover, scanning electron microscopy (SEM) was applied to investigate corn starch granule surface after the SFF process. A maximum ethanol concentration of 110.36 g/l was obtained for native corn starch using a mash concentration of 25%, which resulted in ethanol yield of 85.71%. The optimal conditions for the above yield were found with an enzyme dose of 2.05 ml/kg and pH of 5.0. These results indicate that by using a central composite design, it is possible to determine optimal values of the fermentation parameters for maximum ethanol production. The investigated kinetics model can be used to describe SSF process conducted with granular starch hydrolyzing enzymes. The SEM micrographs reveal randomly distributed holes on the surface of granules.

Efficient method for high-throughput virtual screening based on flexible docking: discovery of novel acetylcholinesterase inhibitors.

PubMed

Mizutani, Miho Yamada; Itai, Akiko

2004-09-23

A method of easily finding ligands, with a variety of core structures, for a given target macromolecule would greatly contribute to the rapid identification of novel lead compounds for drug development. We have developed an efficient method for discovering ligand candidates from a number of flexible compounds included in databases, when the three-dimensional (3D) structure of the drug target is available. The method, named ADAM&EVE, makes use of our automated docking method ADAM, which has already been reported. Like ADAM, ADAM&EVE takes account of the flexibility of each molecule in databases, by exploring the conformational space fully and continuously. Database screening has been made much faster than with ADAM through the tuning of parameters, so that computational screening of several hundred thousand compounds is possible in a practical time. Promising ligand candidates can be selected according to various criteria based on the docking results and characteristics of compounds. Furthermore, we have developed a new tool, EVE-MAKE, for automatically preparing the additional compound data necessary for flexible docking calculation, prior to 3D database screening. Among several successful cases of lead discovery by ADAM&EVE, the finding of novel acetylcholinesterase (AChE) inhibitors is presented here. We performed a virtual screening of about 160 000 commercially available compounds against the X-ray crystallographic structure of AChE. Among 114 compounds that could be purchased and assayed, 35 molecules with various core structures showed inhibitory activities with IC(50) values less than 100 microM. Thirteen compounds had IC(50) values between 0.5 and 10 microM, and almost all their core structures are very different from those of known inhibitors. The results demonstrate the effectiveness and validity of the ADAM&EVE approach and provide a starting point for development of novel drugs to treat Alzheimer's disease.

Production of bio-fuel ethanol from distilled grain waste eluted from Chinese spirit making process.

PubMed

Tan, Li; Sun, Zhaoyong; Zhang, Wenxue; Tang, Yueqin; Morimura, Shigeru; Kida, Kenji

2014-10-01

Distilled grain waste eluted from Chinese spirit making is rich in carbohydrates, and could potentially serve as feedstock for the production of bio-fuel ethanol. Our study evaluated two types of saccharification methods that convert distilled grain waste to monosaccharides: enzymatic saccharification and concentrated H2SO4 saccharification. Results showed that enzymatic saccharification performed unsatisfactorily because of inefficient removal of lignin during pretreatment. Concentrated H2SO4 saccharification led to a total sugar recovery efficiency of 79.0 %, and to considerably higher sugar concentrations than enzymatic saccharification. The process of ethanol production from distilled grain waste based on concentrated H2SO4 saccharification was then studied. The process mainly consisted of concentrated H2SO4 saccharification, solid-liquid separation, decoloration, sugar-acid separation, oligosaccharide hydrolysis, and continuous ethanol fermentation. An improved simulated moving bed system was employed to separate sugars from acid after concentrated H2SO4 saccharification, by which 95.8 % of glucose and 85.8 % of xylose went into the sugar-rich fraction, while 83.3 % of H2SO4 went into the acid-rich fraction. A flocculating yeast strain, Saccharomyces cerevisiae KF-7, was used for continuous ethanol fermentation, which produced an ethanol yield of 91.9-98.9 %, based on glucose concentration.

Establishing high resolution melting analysis: method validation and evaluation for c-RET proto-oncogene mutation screening.

PubMed

Benej, Martin; Bendlova, Bela; Vaclavikova, Eliska; Poturnajova, Martina

2011-10-06

Reliable and effective primary screening of mutation carriers is the key condition for common diagnostic use. The objective of this study is to validate the method high resolution melting (HRM) analysis for routine primary mutation screening and accomplish its optimization, evaluation and validation. Due to their heterozygous nature, germline point mutations of c-RET proto-oncogene, associated to multiple endocrine neoplasia type 2 (MEN2), are suitable for HRM analysis. Early identification of mutation carriers has a major impact on patients' survival due to early onset of medullary thyroid carcinoma (MTC) and resistance to conventional therapy. The authors performed a series of validation assays according to International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) guidelines for validation of analytical procedures, along with appropriate design and optimization experiments. After validated evaluation of HRM, the method was utilized for primary screening of 28 pathogenic c-RET mutations distributed among nine exons of c-RET gene. Validation experiments confirm the repeatability, robustness, accuracy and reproducibility of HRM. All c-RET gene pathogenic variants were detected with no occurrence of false-positive/false-negative results. The data provide basic information about design, establishment and validation of HRM for primary screening of genetic variants in order to distinguish heterozygous point mutation carriers among the wild-type sequence carriers. HRM analysis is a powerful and reliable tool for rapid and cost-effective primary screening, e.g., of c-RET gene germline and/or sporadic mutations and can be used as a first line potential diagnostic tool.

Performance evaluation of structure based and ligand based virtual screening methods on ten selected anti-cancer targets.

PubMed

Ramasamy, Thilagavathi; Selvam, Chelliah

2015-10-15

Virtual screening has become an important tool in drug discovery process. Structure based and ligand based approaches are generally used in virtual screening process. To date, several benchmark sets for evaluating the performance of the virtual screening tool are available. In this study, our aim is to compare the performance of both structure based and ligand based virtual screening methods. Ten anti-cancer targets and their corresponding benchmark sets from 'Demanding Evaluation Kits for Objective In silico Screening' (DEKOIS) library were selected. X-ray crystal structures of protein-ligand complexes were selected based on their resolution. Openeye tools such as FRED, vROCS were used and the results were carefully analyzed. At EF1%, vROCS produced better results but at EF5% and EF10%, both FRED and ROCS produced almost similar results. It was noticed that the enrichment factor values were decreased while going from EF1% to EF5% and EF10% in many cases. Published by Elsevier Ltd.

An in vitro screening method to evaluate chemicals as potential chemotherapeutants to control Aeromonas hydrophila infection in channel catfish

USDA-ARS?s Scientific Manuscript database

Using catfish gill cells G1B and four chemicals (hydrogen peroxide, sodium chloride, potassium permanganate, and D-mannose), the feasibility of using an in vitro screening method to identify potential effective chemotherapeutants was evaluated in this study. In vitro screening results revealed that,...

Dioxins in beef samples from Mexico using a low resolution GC/MS screening method.

PubMed

Naccha, Lidia; Alanis, Guadalupe; Torres, Anabel; Abad, Esteban; Ábalos, Manuela; Rivera, Josep; Heyer, Lorenzo; Morales, Alberto; Waksman, Noemí

2010-01-01

Dioxins in beef were quantified by high resolution gas chromatography coupled to low-resolution mass spectrometry (GC/LRMS). The analyses were performed according to the minimum requirements described in the USEPA 1613 method with some minor modifications. Levels found in the samples were in the range 1.02-8.04 pg WHO-TEQ PCDDs/PCDFs g(-1) fat. For comparison purposes, the maximum level allowed by the European Union is 3 pg WHO-TEQ PCDDs/PCDFs g(-1) fat, and some of these samples surpassed the above-mentioned limit and can be considered as contaminated food. The results confirm that a preliminary screening of dioxins in beef can be performed by GC/LRMS. As far as we know, this is the first report of dioxins in beef in Mexico. After the appropriated tests, the applied methodology could be considered as an alternative screening method for the analysis of PCDD/Fs in other food products.

White-rot fungal pretreatment of wheat straw with Phanerochaete chrysosporium for biohydrogen production: simultaneous saccharification and fermentation.

PubMed

Zhi, Zelun; Wang, Hui

2014-07-01

This paper demonstrates biohydrogen production was enhanced by white-rot fungal pretreatment of wheat straw (WS) through simultaneous saccharification and fermentation (SSF). Wheat straw was pretreated by Phanerochaete chrysosporium at 30 °C under solid state fermentation for 12 days, and lignin was removed about 28.5 ± 1.3 %. Microscopic structure observation combined thermal gravity and differential thermal gravity analysis further showed that the lignocellulose structure obviously disrupted after fungal pretreatment. Subsequently, the pretreated WS and crude cellulases prepared from Trichoderma atroviride were applied in SSF for hydrogen production using Clostridium perfringens. The maximum hydrogen yield was obtained to be 78.5 ± 3.4 ml g(-1)-pretreated WS, which was about 1.8-fold than the unpretreated group. Furthermore, the modified Gompertz model was applied study the progress of cumulative H(2) production. This work developed a novel bio-approach to improve fermentative H(2) yield from lignocellulosic biomass.

Inhibitory effects of phenolic compounds of rice straw formed by saccharification during ethanol fermentation by Pichia stipitis.

PubMed

Wang, Xiahui; Tsang, Yiu Fai; Li, Yuhao; Ma, Xiubing; Cui, Shouqing; Zhang, Tian-Ao; Hu, Jiajun; Gao, Min-Tian

2017-11-01

In this study, it was found that the type of phenolic acids derived from rice straw was the major factor affecting ethanol fermentation by Pichia stipitis. The aim of this study was to investigate the inhibitory effect of phenolic acids on ethanol fermentation with rice straw. Different cellulases produced different ratios of free phenolic acids to soluble conjugated phenolic acids, resulting in different fermentation efficiencies. Free phenolic acids exhibited much higher inhibitory effect than conjugated phenolic acids. The flow cytometry results indicated that the damage to cell membranes was the primary mechanism of inhibition of ethanol fermentation by phenolic acids. The removal of free phenolic acids from the hydrolysates increased ethanol productivity by 2.0-fold, indicating that the free phenolic acids would be the major inhibitors formed during saccharification. The integrated process for ethanol and phenolic acids may constitute a new strategy for the production of low-cost ethanol. Copyright © 2017 Elsevier Ltd. All rights reserved.

Simultaneous saccharification and fermentation of steam exploded duckweed: Improvement of the ethanol yield by increasing yeast titre

PubMed Central

Zhao, X.; Moates, G.K.; Elliston, A.; Wilson, D.R.; Coleman, M.J.; Waldron, K.W.

2015-01-01

This study investigated the conversion of Lemna minor biomass to bioethanol. The biomass was pre-treated by steam explosion (SE, 210 °C, 10 min) and then subjected to simultaneous saccharification and fermentation (SSF) using Cellic® CTec 2 (20 U or 0.87 FPU g−1 substrate) cellulase plus β-glucosidase (2 U g−1 substrate) and a yeast inoculum of 10% (v/v or 8.0 × 107 cells mL−1). At a substrate concentration of 1% (w/v) an ethanol yield of 80% (w/w, theoretical) was achieved. However at a substrate concentration of 20% (w/v), the ethanol yield was lowered to 18.8% (w/w, theoretical). Yields were considerably improved by increasing the yeast titre in the inoculum or preconditioning the yeast on steam exploded liquor. These approaches enhanced the ethanol yield up to 70% (w/w, theoretical) at a substrate concentration of 20% (w/v) by metabolising fermentation inhibitors. PMID:26210138

Comparison of Cardiovascular Risk Screening Methods and Mortality Data among Hungarian Primary Care Population: Preliminary Results of the First Government-Financed Managed Care Program.

PubMed

Móczár, Csaba; Rurik, Imre

2015-09-01

Besides participation in the primary prevention, screening as secondary prevention is an important requirement for primary care services. The effect of this work is influenced by the characteristics of individual primary care practices and doctors' screening habits, as well as by the regulation of screening processes and available financial resources. Between 1999 and 2009, a managed care program was introduced and carried out in Hungary, financed by the government. This financial support and motivation gave the opportunity to increase the number of screenings. 4,462 patients of 40 primary care practices were screened on the basis of SCORE risk assessment. The results of the screening were compared on the basis of two groups of patients, namely: those who had been pre-screened (pre-screening method) for known risk factors in their medical history (smoking, BMI, age, family cardiovascular history), and those randomly screened. The authors also compared the mortality data of participating primary care practices with the regional and national data. The average score was significantly higher in the pre-screened group of patients, regardless of whether the risk factors were considered one by one or in combination. Mortality was significantly lower in the participating primary practices than had been expected on the basis of the national mortality data. This government-financed program was a big step forward to establish a proper screening method within Hungarian primary care. Performing cardiovascular screening of a selected target group is presumably more appropriate than screening within a randomly selected population. Both methods resulted in a visible improvement in regional mortality data, though it is very likely that with pre-screening a more cost-effective selection for screening may be obtained.

A Novel simultaneous-Saccharification-Fermentation Strategy for Efficient Co-fermentation of C5 and C6 Sugars Using Native, Non-GMO Yeasts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Varanasi, Sasidhar; Relue, Patricia

Economic bioethanol production is critically dependent upon the ability to convert both the hexose (C6) and pentose (C5) sugars resulting from cellulose and hemicellulose. C5 sugars are not readily fermentable by native Saccharomyces cerevisiae. Genetically Modified Organisms (GMOs) are designed to ferment xylose, but their stability, ethanol yield, environmental impact, and survival under conditions of industrial fermentation are unproven. In this project, we developed a novel approach for efficient fermentation of both C5 and C6 sugars using native S. Cerevisiae by exploiting its ability to produce ethanol from xylulose - the keto-isomer of xylose. While the isomerization of xylose tomore » xylulose can be accomplished via commercially (and cheaply) available Xylose Isomerase (XI) (Sweetzyme™), this conversion has an extremely unfavorable equilibrium (xylose:xylose is about 5:1). To address this, we developed two alternate strategies. In the first, the two enzymes XI and urease are coimmobilized on solid support particles to enable complete isomerization of xylose to xylulose under pH conditions suitable for fermentation, in a simultaneous-isomerization-fermentation (SIF) mode. The ability of our technology to conduct isomerization of xylose under pH conditions suitable for both saccharification and fermentation opens the possibility of SSF with native yeasts for the first time. Herein, we performed specific research tasks for implementation of our technology in several modes of operation, including simultaneous-isomerization-and-fermentation (SIF), simultaneous-saccharification-and-isomerization (SSI) followed by fermentation, and SSF mode with the biomass feedstock poplar. The projected economics of our process are very favorable in comparison to the costs associated with engineering, licensing and propagating GMOs. This novel fermentation technology is readily accessible to rural farming economies for implementation in cellulosic ethanol production

A novel automatic quantification method for high-content screening analysis of DNA double strand-break response.

PubMed

Feng, Jingwen; Lin, Jie; Zhang, Pengquan; Yang, Songnan; Sa, Yu; Feng, Yuanming

2017-08-29

High-content screening is commonly used in studies of the DNA damage response. The double-strand break (DSB) is one of the most harmful types of DNA damage lesions. The conventional method used to quantify DSBs is γH2AX foci counting, which requires manual adjustment and preset parameters and is usually regarded as imprecise, time-consuming, poorly reproducible, and inaccurate. Therefore, a robust automatic alternative method is highly desired. In this manuscript, we present a new method for quantifying DSBs which involves automatic image cropping, automatic foci-segmentation and fluorescent intensity measurement. Furthermore, an additional function was added for standardizing the measurement of DSB response inhibition based on co-localization analysis. We tested the method with a well-known inhibitor of DSB response. The new method requires only one preset parameter, which effectively minimizes operator-dependent variations. Compared with conventional methods, the new method detected a higher percentage difference of foci formation between different cells, which can improve measurement accuracy. The effects of the inhibitor on DSB response were successfully quantified with the new method (p = 0.000). The advantages of this method in terms of reliability, automation and simplicity show its potential in quantitative fluorescence imaging studies and high-content screening for compounds and factors involved in DSB response.

Management of low-grade cervical abnormalities detected at screening: which method do women prefer?

PubMed

Whynes, D K; Woolley, C; Philips, Z

2008-12-01

To establish whether women with low-grade abnormalities detected during screening for cervical cancer prefer to be managed by cytological surveillance or by immediate colposcopy. TOMBOLA (Trial of Management of Borderline and Other Low-grade Abnormal smears) is a randomized controlled trial comparing alternative management strategies following the screen-detection of low-grade cytological abnormalities. At exit, a sample of TOMBOLA women completed a questionnaire eliciting opinions on their management, contingent valuations (CV) of the management methods and preferences. Within-trial quality of life (EQ-5D) data collected for a sample of TOMBOLA women throughout their follow-up enabled the comparison of self-reported health at various time points, by management method. Once management had been initiated, self-reported health in the colposcopy arm rose relative to that in the surveillance arm, although the effect was short-term only. For the majority of women, the satisfaction ratings and the CV indicated approval of the management method to which they had been randomized. Of the minority manifesting a preference for the method which they had not experienced, relatively more would have preferred colposcopy than would have preferred surveillance. The findings must be interpreted in the light of sample bias with respect to preferences, whereby enthusiasm for colposcopy was probably over-represented amongst trial participants. The study suggests that neither of the management methods is preferred unequivocally; rather, individual women have individual preferences, although many would be indifferent between methods.

Silencing CAFFEOYL SHIKIMATE ESTERASE Affects Lignification and Improves Saccharification in Poplar.

PubMed

Saleme, Marina de Lyra Soriano; Cesarino, Igor; Vargas, Lívia; Kim, Hoon; Vanholme, Ruben; Goeminne, Geert; Van Acker, Rebecca; Fonseca, Fernando Campos de Assis; Pallidis, Andreas; Voorend, Wannes; Junior, José Nicomedes; Padmakshan, Dharshana; Van Doorsselaere, Jan; Ralph, John; Boerjan, Wout

2017-11-01

Caffeoyl shikimate esterase (CSE) was recently shown to play an essential role in lignin biosynthesis in Arabidopsis ( Arabidopsis thaliana ) and later in Medicago truncatula However, the general function of this enzyme was recently questioned by the apparent lack of CSE activity in lignifying tissues of different plant species. Here, we show that down-regulation of CSE in hybrid poplar ( Populus tremula × Populus alba ) resulted in up to 25% reduced lignin deposition, increased levels of p -hydroxyphenyl units in the lignin polymer, and a relatively higher cellulose content. The transgenic trees were morphologically indistinguishable from the wild type. Ultra-high-performance liquid chromatography-mass spectrometry-based phenolic profiling revealed a reduced abundance of several oligolignols containing guaiacyl and syringyl units and their corresponding hydroxycinnamaldehyde units, in agreement with the reduced flux toward coniferyl and sinapyl alcohol. These trees accumulated the CSE substrate caffeoyl shikimate along with other compounds belonging to the metabolic classes of benzenoids and hydroxycinnamates. Furthermore, the reduced lignin amount combined with the relative increase in cellulose content in the CSE down-regulated lines resulted in up to 62% more glucose released per plant upon limited saccharification when no pretreatment was applied and by up to 86% and 91% when acid and alkaline pretreatments were used. Our results show that CSE is not only important for the lignification process in poplar but is also a promising target for the development of improved lignocellulosic biomass crops for sugar platform biorefineries. © 2017 American Society of Plant Biologists. All Rights Reserved.

Screening for Lung Cancer

PubMed Central

Mazzone, Peter J.; Naidich, David P.; Bach, Peter B.

2013-01-01

Background: Lung cancer is by far the major cause of cancer deaths largely because in the majority of patients it is at an advanced stage at the time it is discovered, when curative treatment is no longer feasible. This article examines the data regarding the ability of screening to decrease the number of lung cancer deaths. Methods: A systematic review was conducted of controlled studies that address the effectiveness of methods of screening for lung cancer. Results: Several large randomized controlled trials (RCTs), including a recent one, have demonstrated that screening for lung cancer using a chest radiograph does not reduce the number of deaths from lung cancer. One large RCT involving low-dose CT (LDCT) screening demonstrated a significant reduction in lung cancer deaths, with few harms to individuals at elevated risk when done in the context of a structured program of selection, screening, evaluation, and management of the relatively high number of benign abnormalities. Whether other RCTs involving LDCT screening are consistent is unclear because data are limited or not yet mature. Conclusions: Screening is a complex interplay of selection (a population with sufficient risk and few serious comorbidities), the value of the screening test, the interval between screening tests, the availability of effective treatment, the risk of complications or harms as a result of screening, and the degree with which the screened individuals comply with screening and treatment recommendations. Screening with LDCT of appropriate individuals in the context of a structured process is associated with a significant reduction in the number of lung cancer deaths in the screened population. Given the complex interplay of factors inherent in screening, many questions remain on how to effectively implement screening on a broader scale. PMID:23649455

Process analysis and optimization of simultaneous saccharification and co-fermentation of ethylenediamine-pretreated corn stover for ethanol production.

PubMed

Qin, Lei; Zhao, Xiong; Li, Wen-Chao; Zhu, Jia-Qing; Liu, Li; Li, Bing-Zhi; Yuan, Ying-Jin

2018-01-01

Improving ethanol concentration and reducing enzyme dosage are main challenges in bioethanol refinery from lignocellulosic biomass. Ethylenediamine (EDA) pretreatment is a novel method to improve enzymatic digestibility of lignocellulose. In this study, simultaneous saccharification and co-fermentation (SSCF) process using EDA-pretreated corn stover was analyzed and optimized to verify the constraint factors on ethanol production. Highest ethanol concentration was achieved with the following optimized SSCF conditions at 6% glucan loading: 12-h pre-hydrolysis, 34 °C, pH 5.4, and inoculum size of 5 g dry cell/L. As glucan loading increased from 6 to 9%, ethanol concentration increased from 33.8 to 48.0 g/L, while ethanol yield reduced by 7%. Mass balance of SSCF showed that the reduction of ethanol yield with the increasing solid loading was mainly due to the decrease of glucan enzymatic conversion and xylose metabolism of the strain. Tween 20 and BSA increased ethanol concentration through enhancing enzymatic efficiency. The solid-recycled SSCF process reduced enzyme dosage by 40% (from 20 to 12 mg protein/g glucan) to achieve the similar ethanol concentration (~ 40 g/L) comparing to conventional SSCF. Here, we established an efficient SSCF procedure using EDA-pretreated biomass. Glucose enzymatic yield and yeast viability were regarded as the key factors affecting ethanol production at high solid loading. The extensive analysis of SSCF would be constructive to overcome the bottlenecks and improve ethanol production in cellulosic ethanol refinery.

Dual effect of soluble materials in pretreated lignocellulose on simultaneous saccharification and co-fermentation process for the bioethanol production.

PubMed

Qin, Lei; Li, Xia; Liu, Li; Zhu, Jia-Qing; Guan, Qi-Man; Zhang, Man-Tong; Li, Wen-Chao; Li, Bing-Zhi; Yuan, Ying-Jin

2017-01-01

In this study, wash liquors isolated from ethylenediamine and dry dilute acid pretreated corn stover were used to evaluate the effect of soluble materials in pretreated biomass on simultaneous saccharification and co-fermentation (SSCF) for ethanol production, respectively. Both of the wash liquors had different impacts on enzymatic hydrolysis and fermentation. Enzymatic conversions of glucan and xylan monotonically decreased as wash liquor concentration increased. Whereas, with low wash liquor concentrations, xylose consumption rate, cell viability and ethanol yield were maximally stimulated in fermentation without nutrient supplementary. Soluble lignins were found as the key composition which promoted sugars utilization and cell viability without nutrient supplementary. The dual effects of soluble materials on enzymatic hydrolysis and fermentation resulted in the reduction of ethanol yield as soluble materials increased in SSCF. Copyright © 2016 Elsevier Ltd. All rights reserved.

Measuring lip force by oral screens. Part 1: Importance of screen size and individual variability.

PubMed

Wertsén, Madeleine; Stenberg, Manne

2017-06-01

To reduce drooling and facilitate food transport in rehabilitation of patients with oral motor dysfunction, lip force can be trained using an oral screen. Longitudinal studies evaluating the effect of training require objective methods. The aim of this study was to evaluate a method for measuring lip strength, to investigate normal values and fluctuation of lip force in healthy adults on 1 occasion and over time, to study how the size of the screen affects the force, to evaluate the most appropriate measure of reliability, and to identify force performed in relation to gender. Three different sizes of oral screens were used to measure the lip force for 24 healthy adults on 3 different occasions, during a period of 6 months, using an apparatus based on strain gauge. The maximum lip force as evaluated with this method depends on the area of the screen size. By calculating the projected area of the screen, the lip force could be normalized to an oral screen pressure quantity expressed in kPa, which can be used for comparing measurements from screens with different sizes. Both the mean value and standard deviation were shown to vary between individuals. The study showed no differences regarding gender and only small variation with age. Normal variation over time (months) may be up to 3 times greater than the standard error of measurement at a certain occasion. The lip force increases in relation to the projected area of the screen. No general standard deviation can be assigned to the method and all measurements should be analyzed individually based on oral screen pressure to compensate for different screen sizes.

Virtual screening applications: a study of ligand-based methods and different structure representations in four different scenarios.

PubMed

Hristozov, Dimitar P; Oprea, Tudor I; Gasteiger, Johann

2007-01-01

Four different ligand-based virtual screening scenarios are studied: (1) prioritizing compounds for subsequent high-throughput screening (HTS); (2) selecting a predefined (small) number of potentially active compounds from a large chemical database; (3) assessing the probability that a given structure will exhibit a given activity; (4) selecting the most active structure(s) for a biological assay. Each of the four scenarios is exemplified by performing retrospective ligand-based virtual screening for eight different biological targets using two large databases--MDDR and WOMBAT. A comparison between the chemical spaces covered by these two databases is presented. The performance of two techniques for ligand--based virtual screening--similarity search with subsequent data fusion (SSDF) and novelty detection with Self-Organizing Maps (ndSOM) is investigated. Three different structure representations--2,048-dimensional Daylight fingerprints, topological autocorrelation weighted by atomic physicochemical properties (sigma electronegativity, polarizability, partial charge, and identity) and radial distribution functions weighted by the same atomic physicochemical properties--are compared. Both methods were found applicable in scenario one. The similarity search was found to perform slightly better in scenario two while the SOM novelty detection is preferred in scenario three. No method/descriptor combination achieved significant success in scenario four.

Benchmarking methods and data sets for ligand enrichment assessment in virtual screening.

PubMed

Xia, Jie; Tilahun, Ermias Lemma; Reid, Terry-Elinor; Zhang, Liangren; Wang, Xiang Simon

2015-01-01

Retrospective small-scale virtual screening (VS) based on benchmarking data sets has been widely used to estimate ligand enrichments of VS approaches in the prospective (i.e. real-world) efforts. However, the intrinsic differences of benchmarking sets to the real screening chemical libraries can cause biased assessment. Herein, we summarize the history of benchmarking methods as well as data sets and highlight three main types of biases found in benchmarking sets, i.e. "analogue bias", "artificial enrichment" and "false negative". In addition, we introduce our recent algorithm to build maximum-unbiased benchmarking sets applicable to both ligand-based and structure-based VS approaches, and its implementations to three important human histone deacetylases (HDACs) isoforms, i.e. HDAC1, HDAC6 and HDAC8. The leave-one-out cross-validation (LOO CV) demonstrates that the benchmarking sets built by our algorithm are maximum-unbiased as measured by property matching, ROC curves and AUCs. Copyright © 2014 Elsevier Inc. All rights reserved.

Benchmarking Methods and Data Sets for Ligand Enrichment Assessment in Virtual Screening

PubMed Central

Xia, Jie; Tilahun, Ermias Lemma; Reid, Terry-Elinor; Zhang, Liangren; Wang, Xiang Simon

2014-01-01

Retrospective small-scale virtual screening (VS) based on benchmarking data sets has been widely used to estimate ligand enrichments of VS approaches in the prospective (i.e. real-world) efforts. However, the intrinsic differences of benchmarking sets to the real screening chemical libraries can cause biased assessment. Herein, we summarize the history of benchmarking methods as well as data sets and highlight three main types of biases found in benchmarking sets, i.e. “analogue bias”, “artificial enrichment” and “false negative”. In addition, we introduced our recent algorithm to build maximum-unbiased benchmarking sets applicable to both ligand-based and structure-based VS approaches, and its implementations to three important human histone deacetylase (HDAC) isoforms, i.e. HDAC1, HDAC6 and HDAC8. The Leave-One-Out Cross-Validation (LOO CV) demonstrates that the benchmarking sets built by our algorithm are maximum-unbiased in terms of property matching, ROC curves and AUCs. PMID:25481478

School-based BMI and body composition screening and parent notification in California: methods and messages.

PubMed

Madsen, Kristine A; Linchey, Jennifer

2012-06-01

School-based body mass index (BMI) or body composition screening is increasing, but little is known about the process of parent notification. Since 2001, California has required annual screening of body composition via the FITNESSGRAM, with optional notification. This study sought to identify the prevalence of parental notification when screening is required but notification is optional, and the methods and messages used. Researchers conducted phone interviews with 851 school districts (89%) in California and reviewed notification materials from 54 districts. As of 2008, 53% of California districts notified parents of screening results. Many districts (24%) did not know the reason for their notification policy. Most districts notified parents via a letter mailed home (70%) or sent home with the child (18%). Whereas 79% of sample letters provided students' BMI, only 12% provided an explanation of BMI, and only half provided tips on what parents should do if concerned about their child's results. In California, where body composition screening is required but parent notification is not, approximately half of school districts elect to notify parents of results, most commonly via letter. Most letters do not explain BMI or percent body fat scores, nor do they suggest what parents should do for a child identified as at-risk. Further research to identify interpretable and actionable notification messages for parents will be critical if school-based BMI and body composition screening and notification is to reduce childhood obesity. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.

A Monte-Carlo method which is not based on Markov chain algorithm, used to study electrostatic screening of ion potential

NASA Astrophysics Data System (ADS)

Šantić, Branko; Gracin, Davor

2017-12-01

A new simple Monte Carlo method is introduced for the study of electrostatic screening by surrounding ions. The proposed method is not based on the generally used Markov chain method for sample generation. Each sample is pristine and there is no correlation with other samples. As the main novelty, the pairs of ions are gradually added to a sample provided that the energy of each ion is within the boundaries determined by the temperature and the size of ions. The proposed method provides reliable results, as demonstrated by the screening of ion in plasma and in water.

Simultaneous saccharification and fermentation of Eastern redcedar heartwood and sapwood using a novel size reduction technique.

PubMed

Ramachandriya, Karthikeyan D; Wilkins, Mark; Pardo-Planas, Oscar; Atiyeh, Hasan K; Dunford, Nurhan T; Hiziroglu, Salim

2014-06-01

This study investigated the effect of two wood zones (sapwood versus heartwood) and size reduction techniques [Crumbles® (Crumbles® is a registered trademark of Forest Concepts, LLC, Auburn, WA, USA) particles versus ground particles] on wood glucan-to-ethanol yield after acid bisulfite pretreatment and simultaneous saccharification and fermentation (SSF) of Eastern redcedar. SSFs were conducted at 8% solids loading (w/w dry basis) using Accellerase® 1500 at a loading of 46FPU/g glucan and Saccharomyces cerevisiae D5A for ethanol fermentation. The size reduction technique had no effect on ethanol yield. However, sapwood glucan-to-ethanol yields were significantly greater than heartwood yields. The highest wood glucan-to-ethanol yield of 187L/dryMg (95% of theoretical) was achieved with sapwood crumbled particles in 240h. Ground sapwood, crumbled heartwood and ground heartwood achieved ethanol yields of 89%, 81% and 80% of theoretical in 240h, respectively. Preliminary mass balances showed 100% glucan recovery with crumbled sapwood and extensive (72%) delignification. Copyright © 2014 Elsevier Ltd. All rights reserved.

Development and interlaboratory validation of quantitative polymerase chain reaction method for screening analysis of genetically modified soybeans.

PubMed

Takabatake, Reona; Onishi, Mari; Koiwa, Tomohiro; Futo, Satoshi; Minegishi, Yasutaka; Akiyama, Hiroshi; Teshima, Reiko; Kurashima, Takeyo; Mano, Junichi; Furui, Satoshi; Kitta, Kazumi

2013-01-01

A novel real-time polymerase chain reaction (PCR)-based quantitative screening method was developed for three genetically modified soybeans: RRS, A2704-12, and MON89788. The 35S promoter (P35S) of cauliflower mosaic virus is introduced into RRS and A2704-12 but not MON89788. We then designed a screening method comprised of the combination of the quantification of P35S and the event-specific quantification of MON89788. The conversion factor (Cf) required to convert the amount of a genetically modified organism (GMO) from a copy number ratio to a weight ratio was determined experimentally. The trueness and precision were evaluated as the bias and reproducibility of relative standard deviation (RSDR), respectively. The determined RSDR values for the method were less than 25% for both targets. We consider that the developed method would be suitable for the simple detection and approximate quantification of GMO.

An efficient screening method for the isolation of heterotrophic bacteria influencing growth of diatoms under photoautotrophic conditions.

PubMed

Zecher, Karsten; Jagmann, Nina; Seemann, Philipp; Philipp, Bodo

2015-12-01

Interactions between photoautotrophic diatoms and heterotrophic bacteria are important for the biogeochemical C-cycle in the oceans. Additionally, biofilms formed by diatoms and bacteria are the initiating step of biofouling processes, which causes high costs in shipping. Despite this ecological and economical importance, the knowledge about biochemical and molecular mechanisms underlying these interkingdom interactions is relatively small. For analyzing these mechanisms, laboratory model systems are required. In this study, an efficient screening method for isolating bacteria influencing photoautotrophic diatom growth was established. First, diatom cultures of Phaeodactylum tricornutum and Thalassiosira pseudonana were made axenic by applying β-lactam antibiotics. Second, a non-invasive method for measuring growth of multiple parallel diatom cultures by chlorophyll fluorescence was established. This method allowed semi-quantitative chlorophyll determination of cultures with up to 3 μg (chlorophyll) ml(-1). Axenic diatom cultures were then used for enriching bacteria and led to the isolation of 24 strains influencing growth of both diatom strains in various ways. For example, Rheinheimera sp. strain Tn16 inhibited growth of T. pseudonana, while it stimulated growth and cell aggregation of P. tricornutum. Thus, this screening method is appropriate for isolating heterotrophic bacteria showing different interactions with different diatom species ranging from synergistic to antagonistic. In consecutive applications, this method will be useful to screen for bacterial mutants with altered phenotypes regarding the influence on diatom growth. Copyright © 2015 Elsevier B.V. All rights reserved.

The novel measuring method for screening and assessing chromium content in clothes and shoes materials

NASA Astrophysics Data System (ADS)

Salerno-Kochan, R.

2017-10-01

The aim of this paper is to propose the bioindicative measuring method for screening and assessing the safety of textile and leather materials in relation to chemical threats. This method is based on toxicological assay in which Tetrahymena pyriformis, unicellular organism belonging to protozoans, is used as a test organism. For the realization of the research goal the sensitivity threshold of test organisms to chromium(VI) solutions was identified. The changes in cell development of test organisms in chromium solutions were registered by colorimetric measurements in the presence of alamarBlue® cell viability reagent. Empirical data enabled to fit logistic curves on the base of which the level of chromium toxicity was estimated. In the second step, harmfulness of aqueous extracts obtained from textile and leather samples containing chromium in relation to test organisms was evaluated. The performed research confirmed the high efficiency of the proposed method in screening and assessing chromium content in clothes and shoes materials and showed possibilities of using it in safety assessment of products with regard to chemical risks.

"Inject-mix-react-separate-and-quantitate" (IMReSQ) method for screening enzyme inhibitors.

PubMed

Wong, Edmund; Okhonin, Victor; Berezovski, Maxim V; Nozaki, Tomoyoshi; Waldmann, Herbert; Alexandrov, Kirill; Krylov, Sergey N

2008-09-10

Many regulatory enzymes are considered attractive therapeutic targets, and their inhibitors are potential drug candidates. Screening combinatorial libraries for enzyme inhibitors is pivotal to identifying hit compounds for the development of drugs targeting regulatory enzymes. Here, we introduce the first inhibitor screening method that consumes only nanoliters of the reactant solutions and is applicable to regulatory enzymes. The method is termed inject-mix-react-separate-and-quantitate (IMReSQ) and includes five steps. First, nanoliter volumes of substrate, candidate inhibitor, and enzyme solutions are injected by pressure into a capillary as separate plugs. Second, the plugs are mixed inside this capillary microreactor by transverse diffusion of laminar flow profiles. Third, the reaction mixture is incubated to form the enzymatic product. Fourth, the product is separated from the substrate inside the capillary by electrophoresis. Fifth, the amounts of the product and substrate are quantitated. In this proof-of-principle work, we applied IMReSQ to study inhibition of recently cloned protein farnesyltransferase from parasite Entamoeba histolytica. This enzyme is a potential therapeutic target for antiparasitic drugs. We identified three previously unknown inhibitors of this enzyme and proved that IMReSQ could be used for quantitatively ranking the potencies of inhibitors.

A comparison of two visual inspection methods for cervical cancer screening among HIV-infected women in Kenya

PubMed Central

Sneden, Jennifer; Leslie, Hannah H; Abdulrahim, Naila; Maloba, May; Bukusi, Elizabeth; Cohen, Craig R

2014-01-01

Abstract Objective To determine the optimal strategy for cervical cancer screening in women with human immunodeficiency virus (HIV) infection by comparing two strategies: visual inspection of the cervix with acetic acid (VIA) and VIA followed immediately by visual inspection with Lugol’s iodine (VIA/VILI) in women with a positive VIA result. Methods Data from a cervical cancer screening programme embedded in two HIV clinic sites in western Kenya were evaluated. Women at a central site underwent VIA, while women at a peripheral site underwent VIA/VILI. All women positive for cervical intraepithelial neoplasia grade 2 or worse (CIN 2+) on VIA and/or VILI had a confirmatory colposcopy, with a biopsy if necessary. Overall test positivity, positive predictive value (PPV) and the CIN 2+ detection rate were calculated for the two screening methods, with biopsy being the gold standard. Findings Between October 2007 and October 2010, 2338 women were screened with VIA and 1124 with VIA/VILI. In the VIA group, 26.4% of the women tested positive for CIN 2+; in the VIA/VILI group, 21.7% tested positive (P < 0.01). Histologically confirmed CIN 2+ was detected in 8.9% and 7.8% (P = 0.27) of women in the VIA and VIA/VILI groups, respectively. The PPV of VIA for biopsy-confirmed CIN 2+ in a single round of screening was 35.2%, compared with 38.2% for VIA/VILI (P = 0.41). Conclusion The absence of any differences between VIA and VIA/VILI in detection rates or PPV for CIN 2+ suggests that VIA, an easy testing procedure, can be used alone as a cervical cancer screening strategy in low-income settings. PMID:24700979

Rapid screening method for male DNA by using the loop-mediated isothermal amplification assay.

PubMed

Kitamura, Masashi; Kubo, Seiji; Tanaka, Jin; Adachi, Tatsushi

2017-08-12

Screening for male-derived biological material from collected samples plays an important role in criminal investigations, especially those involving sexual assaults. We have developed a loop-mediated isothermal amplification (LAMP) assay targeting multi-repeat sequences of the Y chromosome for detecting male DNA. Successful amplification occurred with 0.5 ng of male DNA under isothermal conditions of 61 to 67 °C, but no amplification occurred with up to 10 ng of female DNA. Under the optimized conditions, the LAMP reaction initiated amplification within 10 min and amplified for 20 min. The LAMP reaction was sensitive at levels as low as 1-pg male DNA, and a quantitative LAMP assay could be developed because of the strong correlation between the reaction time and the amount of template DNA in the range of 10 pg to 10 ng. Furthermore, to apply the LAMP assay to on-site screening for male-derived samples, we evaluated a protocol using a simple DNA extraction method and a colorimetric intercalating dye that allows detection of the LAMP reaction by evaluating the change in color of the solution. Using this protocol, samples of male-derived blood and saliva stains were processed in approximately 30 min from DNA extraction to detection. Because our protocol does not require much hands-on time or special equipment, this LAMP assay promises to become a rapid and simple screening method for male-derived samples in forensic investigations.

The SOBANE risk management strategy and the Déparis method for the participatory screening of the risks.

PubMed

Malchaire, J B

2004-08-01

The first section of the document describes a risk-prevention strategy, called SOBANE, in four levels: screening, observation, analysis and expertise. The aim is to make risk prevention faster, more cost effective, and more effective in coordinating the contributions of the workers themselves, their management, the internal and external occupational health (OH) practitioners and the experts. These four levels are: screening, where the risk factors are detected by the workers and their management, and obvious solutions are implemented; observation, where the remaining problems are studied in more detail, one by one, and the reasons and the solutions are discussed in detail; analysis, where, when necessary, an OH practitioner is called upon to carry out appropriate measurements to develop specific solutions; expertise, where, in very sophisticated and rare cases, the assistance of an expert is called upon to solve a particular problem. The method for the participatory screening of the risks (in French: Dépistage Participatif des Risques), Déparis, is proposed for the first level screening of the SOBANE strategy. The work situation is systematically reviewed and all the aspects conditioning the easiness, the effectiveness and the satisfaction at work are discussed, in search of practical prevention measures. The points to be studied more in detail at level 2, observation, are identified. The method is carried out during a meeting of key workers and technical staff. The method proves to be simple, sparing in time and means and playing a significant role in the development of a dynamic plan of risk management and of a culture of dialogue in the company.

An experience of qualified preventive screening: shiraz smart screening software.

PubMed

Islami Parkoohi, Parisa; Zare, Hashem; Abdollahifard, Gholamreza

2015-01-01

Computerized preventive screening software is a cost effective intervention tool to address non-communicable chronic diseases. Shiraz Smart Screening Software (SSSS) was developed as an innovative tool for qualified screening. It allows simultaneous smart screening of several high-burden chronic diseases and supports reminder notification functionality. The extent in which SSSS affects screening quality is also described. Following software development, preventive screening and annual health examinations of 261 school staff (Medical School of Shiraz, Iran) was carried out in a software-assisted manner. To evaluate the quality of the software-assisted screening, we used quasi-experimental study design and determined coverage, irregular attendance and inappropriateness proportions in relation with the manual and software-assisted screening as well as the corresponding number of requested tests. In manual screening method, 27% of employees were covered (with 94% irregular attendance) while by software-assisted screening, the coverage proportion was 79% (attendance status will clear after the specified time). The frequency of inappropriate screening test requests, before the software implementation, was 41.37% for fasting plasma glucose, 41.37% for lipid profile, 0.84% for occult blood, 0.19% for flexible sigmoidoscopy/colonoscopy, 35.29% for Pap smear, 19.20% for mammography and 11.2% for prostate specific antigen. All of the above were corrected by the software application. In total, 366 manual screening and 334 software-assisted screening tests were requested. SSSS is an innovative tool to improve the quality of preventive screening plans in terms of increased screening coverage, reduction in inappropriateness and the total number of requested tests.

Validation of a Method To Screen for Pulmonary Hypertension in Advanced Idiopathic Pulmonary Fibrosis*

PubMed Central

Zisman, David A.; Karlamangla, Arun S.; Kawut, Steven M.; Shlobin, Oksana A.; Saggar, Rajeev; Ross, David J.; Schwarz, Marvin I.; Belperio, John A.; Ardehali, Abbas; Lynch, Joseph P.; Nathan, Steven D.

2008-01-01

Background We have developed a method to screen for pulmonary hypertension (PH) in idiopathic pulmonary fibrosis (IPF) patients, based on a formula to predict mean pulmonary artery pressure (MPAP) from standard lung function measurements. The objective of this study was to validate this method in a separate group of IPF patients. Methods Cross-sectional study of 60 IPF patients from two institutions. The accuracy of the MPAP estimation was assessed by examining the correlation between the predicted and measured MPAPs and the magnitude of the estimation error. The discriminatory ability of the method for PH was assessed using the area under the receiver operating characteristic curve (AUC). Results There was strong correlation in the expected direction between the predicted and measured MPAPs (r = 0.72; p < 0.0001). The estimated MPAP was within 5 mm Hg of the measured MPAP 72% of the time. The AUC for predicting PH was 0.85, and did not differ by institution. A formula-predicted MPAP > 21 mm Hg was associated with a sensitivity, specificity, positive predictive value, and negative predictive value of 95%, 58%, 51%, and 96%, respectively, for PH defined as MPAP from right-heart catheterization > 25 mm Hg. Conclusions A prediction formula for MPAP using standard lung function measurements can be used to screen for PH in IPF patients. PMID:18198245

Implementing a method of screening one-well hydraulic barrier design alternatives.

PubMed

Rubin, Hillel; Shoemaker, Christine A; Köngeter, Jürgen

2009-01-01

This article provides details of applying the method developed by the authors (Rubin et al. 2008b) for screening one-well hydraulic barrier design alternatives. The present article with its supporting information (manual and electronic spreadsheets with a case history example) provides the reader complete details and examples of solving the set of nonlinear equations developed by Rubin et al. (2008b). It allows proper use of the analytical solutions and also depicting the various charts given by Rubin et al. (2008b). The final outputs of the calculations are the required position and the discharge of the pumping well. If the contaminant source is nonaqueous phase liquid (NAPL) entrapped within the aquifer, then the method provides an estimate of the aquifer remediation progress (which is a by-product) due to operating the hydraulic barrier.

Ethanol production from banana peels using statistically optimized simultaneous saccharification and fermentation process.

PubMed

Oberoi, Harinder Singh; Vadlani, Praveen V; Saida, Lavudi; Bansal, Sunil; Hughes, Joshua D

2011-07-01

Dried and ground banana peel biomass (BP) after hydrothermal sterilization pretreatment was used for ethanol production using simultaneous saccharification and fermentation (SSF). Central composite design (CCD) was used to optimize concentrations of cellulase and pectinase, temperature and time for ethanol production from BP using SSF. Analysis of variance showed a high coefficient of determination (R(2)) value of 0.92 for ethanol production. On the basis of model graphs and numerical optimization, the validation was done in a laboratory batch fermenter with cellulase, pectinase, temperature and time of nine cellulase filter paper unit/gram cellulose (FPU/g-cellulose), 72 international units/gram pectin (IU/g-pectin), 37 °C and 15 h, respectively. The experiment using optimized parameters in batch fermenter not only resulted in higher ethanol concentration than the one predicted by the model equation, but also saved fermentation time. This study demonstrated that both hydrothermal pretreatment and SSF could be successfully carried out in a single vessel, and use of optimized process parameters helped achieve significant ethanol productivity, indicating commercial potential for the process. To the best of our knowledge, ethanol concentration and ethanol productivity of 28.2 g/l and 2.3 g/l/h, respectively from banana peels have not been reported to date. Copyright © 2011 Elsevier Ltd. All rights reserved.

Assessment of Knowledge of Breast Cancer and Screening Methods among Nurses in University Hospitals in Addis Ababa, Ethiopia, 2011

PubMed Central

Lemlem, Semarya Berhe; Sinishaw, Worknish; Hailu, Mignote; Abebe, Mesfin; Aregay, Alemseged

2013-01-01

Background. According to the American Cancer Society, about 1.3 million women will be diagnosed with breast cancer annually worldwide and about 465,000 will die from the disease. In Ethiopia breast cancer is the second most often occurring cancer among women. Early diagnosis is especially important for breast cancer because the disease responds best to treatment before it has spread. Objective. To assess knowledge of breast cancer and screening methods among nurses in university hospitals. Method. This cross-sectional descriptive study used simple random sampling on sample of 281 nurses. Structured questionnaires draw out responses about knowledge and screening method of nurses in regard to breast cancer. Bivariate analysis was used principally and variables were then entered to multiple logistic regressions model for controlling the possible effect of confounders and the variables which have significant association were identified on the basis of OR, with 95% CI and P value. Results. The findings of this study revealed that only 156 (57.8%) of them were knowledgeable about breast cancer and its screening and 114 (42.2%) were not. Knowledge of breast cancer was found to be significantly associated with regular course in nursing, family history of respondents, and unit of work. Conclusion and Recommendation. The results of this study indicate that the knowledge of nurses is not satisfying and highlight the need to improve the content in the nursing curriculum and to undergo more workplace training in the area of breast cancer and screening methods. PMID:23986873

Robust Microplate-Based Methods for Culturing and in Vivo Phenotypic Screening of Chlamydomonas reinhardtii.

PubMed

Haire, Timothy C; Bell, Cody; Cutshaw, Kirstin; Swiger, Brendan; Winkelmann, Kurt; Palmer, Andrew G

2018-01-01

Chlamydomonas reinhardtii (Cr), a unicellular alga, is routinely utilized to study photosynthetic biochemistry, ciliary motility, and cellular reproduction. Its minimal culture requirements, unicellular morphology, and ease of transformation have made it a popular model system. Despite its relatively slow doubling time, compared with many bacteria, it is an ideal eukaryotic system for microplate-based studies utilizing either, or both, absorbance as well as fluorescence assays. Such microplate assays are powerful tools for researchers in the areas of toxicology, pharmacology, chemical genetics, biotechnology, and more. However, while microplate-based assays are valuable tools for screening biological systems, these methodologies can significantly alter the conditions in which the organisms are cultured and their subsequent physiology or morphology. Herein we describe a novel method for the microplate culture and in vivo phenotypic analysis of growth, viability, and photosynthetic pigments of C. reinhardtii . We evaluated the utility of our assay by screening silver nanoparticles for their effects on growth and viability. These methods are amenable to a wide assortment of studies and present a significant advancement in the methodologies available for research involving this model organism.

Identification and Characterization of a 25 kDa Protein That Is Indispensable for the Efficient Saccharification of Eisenia bicyclis in the Digestive Fluid of Aplysia kurodai

PubMed Central

Tsuji, Akihiko; Kuwamura, Shuji; Shirai, Akihiro; Yuasa, Keizo

2017-01-01

The digestive fluid of the sea hare Aplysia kurodai can liberate approximately 2.5 mg of glucose from 10 mg of dried Eisenia bicyclis powder. Although laminaran, a major storage polysaccharide in E. bicyclis, is easily digested to glucose by the synergistic action of the 110 and 210 kDa A. kurodai β-glucosidases (BGLs), glucose is not liberated from E. bicyclis by direct incubation with these BGLs. To clarify this discrepancy, we searched for an Eisenia hydrolysis enhancing protein (EHEP) in the digestive fluid of A. kurodai. A novel 25 kDa protein that enhances E. bicyclis saccharification by β-glucosidases was purified to a homogeneous state from the digestive fluid of A. kurodai, and its cDNA was cloned from total cDNAs reverse-transcribed from hepatopancreas total RNA. The E. bicyclis extract strongly inhibited BGLs, suggesting some compound within this brown alga functioned as a feeding deterrent. However, when E. bicyclis was incubated with BGLs in the presence of EHEP, glucose production was markedly increased. As E. bicyclis is rich in phlorotannin, which are only found in brown algae, our study suggested that these compounds are the main BGL inhibitors in E. bicyclis extract. EHEP protects BGLs from phlorotannin inhibition by binding to phlorotannins and forming an insoluble complex with phloroglucinol and phlorotannins. These findings indicated that EHEP plays a key role in the saccharification of brown seaweeds containing phlorotannins in the digestive fluid of A. kurodai. This is the first report of EHEP as a phlorotannin-binding protein that protects BGLs from inhibition. PMID:28129373

High prevalence of bacteriuria in pregnancy and its screening methods in north India.

PubMed

Bandyopadhyay, Sutapa; Thakur, J S; Ray, Pallab; Kumar, Rajesh

2005-05-01

The study aims at finding out the prevalence of bacteruria in pregnancy in an urban setting and ascertaining methods to screen them in primary care clinics. A total of 1 61 pregnant ladies visiting a primary care clinic were screened for bacteriuria based on the symptomatology. Urine culture was done to know the prevalence of bacteriuria. Sensitivities and specificities were calculated for each symptom and risk assessment. A score card was developed based on combination of positive risk assessment and constellation of symptoms. Prevalence of symptomatic and asymptomatic bacteriuria was found to be 19.87% and 4.34% respectively. Prevalence of bacteriuria was significantly high among those who had intercourse more frequently and those with less water intake. Those with a score of more than or equal to 4, as per score card were 60% more likely to suffer from bacteriuria. When combined with microscopic examination for leucocytes on positively screened, the positive predictive value was found to be 89%. It is concluded that prevalence of symptomatic bacteriuria is common among pregnant women. Syndromic management of cases on the basis of score card is helpful in resource constraint areas. This may be combined with microscopic examination of urine to entail rational use of antibiotics.

Cognitive Change Questionnaire as a method for cognitive impairment screening

PubMed Central

Damin, Antonio Eduardo; Nitrini, Ricardo; Brucki, Sonia Maria Dozzi

2015-01-01

The Cognitive Change Questionnaire (CCQ) was created as an effective measure of cognitive change that is easy to use and suitable for application in Brazil. Objective To evaluate whether the CCQ can accurately distinguish normal subjects from individuals with Mild Cognitive Impairment (MCI) and/or early stage dementia and to develop a briefer questionnaire, based on the original 22-item CCQ (CCQ22), that contains fewer questions. Methods A total of 123 individuals were evaluated: 42 healthy controls, 40 patients with MCI and 41 with mild dementia. The evaluation was performed using cognitive tests based on individual performance and on questionnaires administered to informants. The CCQ22 was created based on a selection of questions that experts deemed useful in screening for early stage dementia. Results The CCQ22 showed good accuracy for distinguishing between the groups. Statistical models selected the eight questions with the greatest power to discriminate between the groups. The AUC ROC corresponding to the final version of the 8-item CCQ (CCQ8), demonstrated good accuracy in differentiating between groups, good correlation with the final diagnosis (r=0.861) and adequate internal consistency (Cronbach's α=0.876). Conclusion The CCQ8 can be used to accurately differentiate between normal subjects and individuals with cognitive impairment, constituting a brief and appropriate instrument for cognitive screening. PMID:29213967

Simultaneous saccharification and extractive fermentation of lignocellulosic materials into lactic acid in a two-zone fermentor-extractor system.

PubMed

Iyer, P V; Lee, Y Y

1999-01-01

Simultaneous saccharification and extractive fermentation of lignocellulosic materials into lactic acid was investigated using a two-zone bioreactor. The system is composed of an immobilized cell reactor, a separate column reactor containing the lignocellulosic substrate and a hollow-fiber membrane. It is operated by recirculating the cell free enzyme (cellulase) solution from the immobilized cell reactor to the column reactor through the membrane. The enzyme and microbial reactions thus occur at separate locations, yet simultaneously. This design provides flexibility in reactor operation as it allows easy separation of the solid substrate from the microorganism, in situ removal of the product and, if desired, different temperatures in the two reactor sections. This reactor system was tested using pretreated switchgrass as the substrate. It was operated under a fed-batch mode with continuous removal of lactic acid by solvent extraction. The overall lactic acid yield obtainable from this bioreactor system is 77% of the theoretical.

Statistical studies of animal response data from USF toxicity screening test method

NASA Technical Reports Server (NTRS)

Hilado, C. J.; Machado, A. M.

1978-01-01

Statistical examination of animal response data obtained using Procedure B of the USF toxicity screening test method indicates that the data deviate only slightly from a normal or Gaussian distribution. This slight departure from normality is not expected to invalidate conclusions based on theoretical statistics. Comparison of times to staggering, convulsions, collapse, and death as endpoints shows that time to death appears to be the most reliable endpoint because it offers the lowest probability of missed observations and premature judgements.

Development of a semi-continuous two-stage simultaneous saccharification and fermentation process for enhanced 2,3-butanediol production by Klebsiella oxytoca.

PubMed

Moon, S-K; Kim, D-K; Park, J M; Min, J; Song, H

2018-04-01

Klebsiella oxytoca naturally produces a large amount of 2,3-butanediol (2,3-BD), a promising chemical with wide industrial applications, along with various by-products. Previously, we have developed a metabolically engineered K. oxytoca ΔldhA ΔpflB strain to reduce the formation of by-products. To improve 2,3-BD productivity and examine the stability of K. oxytoca ΔldhA ΔpflB strain for industrial application, a semi-continuous two-stage simultaneous saccharification and fermentation (STSSF) process was developed. The STSSF with the K. oxytoca ΔldhA ΔpflB mutant using cassava as a carbon source could produce 108 ± 3·73 g (2,3- BD )  l -1 with a yield of 0·45 g (2,3- BD )  g (glucose) -1 and a productivity of 3·00 g (2,3- BD ) l -1  h -1 . No apparent changes in the final titre, yield and productivity of 2,3-BD were observed for up to 20 cycles of STSSF. Also, microbial contamination and spontaneous mutation of the host strain with potential detrimental effects on fermentation efficiency did not occur during the whole fermentation period. These results strongly underpin that the K. oxytoca ΔldhA ΔpflB mutant is stable and that the STSSF process is commercially exploitable. There is growing interest in the production of 2,3-butanediol (2,3-BD) from renewable resources by microbial fermentation because of its wide applications to specialty and commodity chemical industries. Klebsiella oxytoca usually produces 2,3-BD as a major end product during the fermentation of carbohydrates. This is the first study to provide a high-efficiency simultaneous saccharification and 2,3-BD fermentation process. Also, this study proves the stability of a metabolically engineered 2,3-BD overproducing K. oxytoca strain for industrial application. © 2018 The Society for Applied Microbiology.

Influence of fiber degradation and concentration of fermentable sugars on simultaneous saccharification and fermentation of high-solids spruce slurry to ethanol.

PubMed

Hoyer, Kerstin; Galbe, Mats; Zacchi, Guido

2013-10-08

Saccharification and fermentation of pretreated lignocellulosic materials, such as spruce, should be performed at high solids contents in order to reduce the cost of the produced bioethanol. However, this has been shown to result in reduced ethanol yields or a complete lack of ethanol production. Previous studies have shown inconsistent results when prehydrolysis is performed at a higher temperature prior to the simultaneous saccharification and fermentation (SSF) of steam-pretreated lignocellulosic materials. In some cases, a significant increase in overall ethanol yield was reported, while in others, a slight decrease in ethanol yield was observed. In order to investigate the influence of prehydrolysis on high-solids SSF of steam-pretreated spruce slurry, in the present study, the presence of fibers and inhibitors, degree of fiber degradation and initial fermentable sugar concentration has been studied. SSF of whole steam-pretreated spruce slurry at a solids content of 13.7% water-insoluble solids (WIS) resulted in a very low overall ethanol yield, mostly due to poor fermentation. The yeast was, however, able to ferment the washed slurry and the liquid fraction of the pretreated slurry. Performing prehydrolysis at 48°C for 22 hours prior to SSF of the whole pretreated slurry increased the overall ethanol yield from 3.9 to 62.1%. The initial concentration of fermentable sugars in SSF could not explain the increase in ethanol yield in SSF with prehydrolysis. Although the viscosity of the material did not appear to decrease significantly during prehydrolysis, the degradation of the fibers prior to the addition of the yeast had a positive effect on ethanol yield when using whole steam-pretreated spruce slurry. The results of the present study suggest that the increase in ethanol yield from SSF when performing prehydrolysis is a result of fiber degradation rather than a decrease in viscosity. The increased concentration of fermentable sugars at the beginning of the

Evaluation of a Rapid Method for Screening Heat Stress Tolerance Using Three Korean Wheat (Triticum aestivum L.) Cultivars.

PubMed

Truong, Hai An; Jeong, Chan Young; Lee, Won Je; Lee, Byung Cheon; Chung, Namhyun; Kang, Chon-Sik; Cheong, Young-Keun; Hong, Suk-Whan; Lee, Hojoung

2017-07-19

Thermotolerance in plants is a topic of concern given the current trends in global warming. Here, we aimed to develop a rapid and reproducible screening method for selection of heat stress-tolerant wheat varieties to expedite the breeding process. We tested the robustness of the screen in three Korean wheat cultivars, "BackJung", "KeumKang", and "ChoKyeong". We showed that 4-day-old seedlings of "KeumKang" had the highest survival rates after a 45 °C treatment for 20 h. Moreover, the ability to retain chlorophyll and antioxidant activity was also highest in "KeumKang". The increase in malondialdehyde content in "ChoKyeong" indicated that this cultivar showed the greatest damage after heat stress. Collectively, our results showed that "KeumKang" is the most heat-tolerant cultivar of the three examined. In conclusion, the most reliable and rapid screening method in our investigation was survival rate examined at lethal temperature.

[Ideas and methods on efficient screening of traditional medicines for anti-osteoporosis activity based on M-Act/Tox integrated evaluation using zebrafish].

PubMed

Wang, Mo; Ling, Jie; Chen, Ying; Song, Jie; Sun, E; Shi, Zi-Qi; Feng, Liang; Jia, Xiao-Bin; Wei, Ying-Jie

2017-11-01

The increasingly apparent liver injury problems of bone strengthening Chinese medicines have brought challenges for clinical application, and it is necessary to consider both effectiveness and safety in screening anti-osteoporosis Chinese medicines. Metabolic transformation is closely related to drug efficacy and toxicity, so it is significant to comprehensively consider metabolism-action/toxicity(M-Act/Tox) for screening anti-osteoporosis Chinese medicines. The current evaluation models and the number of compounds(including metabolites) severely restrict efficient screening in vivo. By referring to previous relevant research and domestic and abroad literature, zebrafish M-Act/Tox integrative method was put forward for efficiently screening anti-osteoporosis herb medicines, which has organically integrated zebrafish metabolism model, osteoporosis model and toxicity evaluation method. This method can break through the bottleneck and blind spots that trace compositions can't achieve efficient and integrated in vivo evaluation, and realize both efficient and comprehensive screening on anti-osteoporosis traditional medicines based on in vivo process taking both safety and effectiveness into account, which is significant to accelerate discovery of effective and safe innovative traditional Chinese medicines for osteoporosis. Copyright© by the Chinese Pharmaceutical Association.

Cystic fibrosis: to screen or not to screen? Involving a Citizens' jury in decisions on screening carrier.

PubMed

Mosconi, Paola; Castellani, Carlo; Villani, Walter; Satolli, Roberto

2015-12-01

In recent years, the continuous improvements in molecular biology techniques have made it possible to detect carriers for several genetic conditions, including cystic fibrosis (CF). In some countries, CF carrier screening is offered to increasing subset of the general population. Offering of carrier screening at a population level should not be decided by local health authorities only, without consulting citizens' preferences. One way to involve citizens in the decision process might be to a Citizens' jury, a method of deliberative democracy. The object of the study is to produce a recommendation statement about CF carrier screening using a Citizens' jury. As this is a new method in the field, the study also provided the opportunity to evaluate its effectiveness. The project is designed and managed by an executive committee. The whole process is superintended by a multidisciplinary scientific committee. The 16 members of the jury attend a 1 day meeting, assisted by a non-medical and unbiased facilitator. Informative material was prepared and distributed 15 days before the jury meeting; during the meeting, experts and witnesses interact directly with all the jurors through questions and answers. All except one member of the jury felt positively about the Health Service actively providing population carrier screening for CF. The final statement was available to public, clinicians, researchers and decision-makers. In general, a Citizens' jury is a feasible method for involving citizens in public health decision-making process and in particular for obtaining a community view about CF carrier screening. © 2014 The Authors Health Expectations Published by John Wiley & Sons Ltd.

Finite Temperature Densities via the S-Function Method with Application to Electron Screening in Plasmas

NASA Astrophysics Data System (ADS)

Watrous, Mitchell James

1997-12-01

A new approach to the Green's-function method for the calculation of equilibrium densities within the finite temperature, Kohn-Sham formulation of density functional theory is presented, which extends the method to all temperatures. The contour of integration in the complex energy plane is chosen such that the density is given by a sum of Green's function differences evaluated at the Matsubara frequencies, rather than by the calculation and summation of Kohn-Sham single-particle wave functions. The Green's functions are written in terms of their spectral representation and are calculated as the solutions of their defining differential equations. These differential equations are boundary value problems as opposed to the standard eigenvalue problems. For large values of the complex energy, the differential equations are further simplified from second to first-order by writing the Green's functions in terms of logarithmic derivatives. An asymptotic expression for the Green's functions is derived, which allows the sum over Matsubara poles to be approximated. The method is applied to the screening of nuclei by electrons in finite temperature plasmas. To demonstrate the method's utility, and to illustrate its advantages, the results of previous wave function type calculations for protons and neon nuclei are reproduced. The method is also used to formulate a new screening model for fusion reactions in the solar core, and the predicted reaction rate enhancements factors are compared with existing models.

Rapid, convenient method for screening imidazole-containing compounds for heme oxygenase inhibition.

PubMed

Vlahakis, Jason Z; Rahman, Mona N; Roman, Gheorghe; Jia, Zongchao; Nakatsu, Kanji; Szarek, Walter A

2011-01-01

Sensitive assays for measuring heme oxygenase activity have been based on the gas-chromatographic detection of carbon monoxide using elaborate, expensive equipment. The present study describes a rapid and convenient method for screening imidazole-containing candidates for inhibitory activity against heme oxygenase using a plate reader, based on the spectroscopic evaluation of heme degradation. A PowerWave XS plate reader was used to monitor the absorbance (as a function of time) of heme bound to purified truncated human heme oxygenase-1 (hHO-1) in the individual wells of a standard 96-well plate (with or without the addition of a test compound). The degradation of heme by heme oxygenase-1 was initiated using l-ascorbic acid, and the collected relevant absorbance data were analyzed by three different methods to calculate the percent control activity occurring in wells containing test compounds relative to that occurring in control wells with no test compound present. In the cases of wells containing inhibitory compounds, significant shifts in λ(max) from 404 to near 412 nm were observed as well as a decrease in the rate of heme degradation relative to that of the control. Each of the three methods of data processing (overall percent drop in absorbance over 1.5h, initial rate of reaction determined over the first 5 min, and estimated pseudo first-order reaction rate constant determined over 1.5h) gave similar and reproducible results for percent control activity. The fastest and easiest method of data analysis was determined to be that using initial rates, involving data acquisition for only 5 min once reactions have been initiated using l-ascorbic acid. The results of the study demonstrate that this simple assay based on the spectroscopic detection of heme represents a rapid, convenient method to determine the relative inhibitory activity of candidate compounds, and is useful in quickly screening a series or library of compounds for heme oxygenase inhibition

D-lactic acid production from dry biomass of Hydrodictyon reticulatum by simultaneous saccharification and co-fermentation using Lactobacillus coryniformis subsp. torquens.

PubMed

Nguyen, Cuong Mai; Kim, Jin-Seog; Song, Jae Kwang; Choi, Gyung Ja; Choi, Yong Ho; Jang, Kyoung Soo; Kim, Jin-Cheol

2012-12-01

D-lactic acid production from dry biomass of the microalga, Hydrodictyon reticulatum, was carried out in a 5-l jar fermentor (initial pH 6, 34 °C using CaCO(3) as a neutralizing agent) through simultaneous saccharification and co-fermentation using the Lactobacillus coryniformis subsp. torquens. After 36 h, 36.6 g lactic acid/l was produced from 80 g H. reticulatum/l in the medium containing 3 g yeast extract/l and 3 g peptone/l in the absence of mineral salts. The maximum productivity, average productivity and yield were 2.38 g/l h, 1.02 g/l h and 45.8 %, respectively. The optical purity of D-Lactic acid ranged from 95.8-99.6 %. H. reticulatum is thus a promising biomass material for the production of D-Lactic acid.

Factors Influencing Choices for Colorectal Cancer Screening Among Previously Unscreened African and Caucasian Americans: Findings from a Triangulation Mixed Methods Investigation

PubMed Central

Ruffin, Mack T.; Creswell, John W.; Jimbo, Masahito

2014-01-01

We investigated factors that influence choice of colorectal cancer (CRC) screening test and assessed the most- and least-preferred options among fecal occult blood testing (FOBT), flexible sigmoidoscopy, colonoscopy, and double contrast barium enema among adults with varied race, gender, and geographic region demographics. Mixed methods data collection consisted of 10 focus group interviews and a survey of the 93 focus group participants. Participants were ≥50 years of age and reported not having been screened for colorectal cancer in the last ten years. Analyses examined differences by race, gender, and geographic location. Participants had modest knowledge about CRC and there were fewer correct answers to knowledge questions by African Americans. Participants recognized value of early detection, and identified health symptoms and their doctor's recommendation as influential for obtaining CRC screening. They chose colonoscopy and FOBT as the most preferred tests, while barium enema was least preferred. The analysis revealed intra-group variations in preference, though there were no significant differences by race, gender, or location. Openness of discussing this sensitive topic, lack of knowledge about colorectal cancer and screening costs, and diversity of preferences expressed within study groups suggest the importance of patient-physician dialogue about colorectal cancer screening options. New approaches to promoting colorectal cancer screening need to explore methods to facilitate patients establishing and expressing preferences among the screening options. PMID:19082695

Gastric Cancer Screening by Combined Determination of Serum Helicobacter pylori Antibody and Pepsinogen Concentrations: ABC Method for Gastric Cancer Screening.

PubMed

Chen, Xian-Zhe; Huang, Cheng-Zhi; Hu, Wei-Xian; Liu, Ying; Yao, Xue-Qing

2018-05-20

Gastroscopy combined with gastric mucosa biopsies is currently regarded as a gold standard for diagnosis of gastric cancer. However, its application is restricted in clinical practice due to its invasive property. A new noninvasive population screening process combining the assay of anti-Helicobacter pylori antibody and serum pepsinogen (PG) (ABC method) is adopted to recognize the high-risk patients for further endoscopy examination, avoiding the unnecessary gastroscopy for most population and saving the cost consumption for mass screening annually. Nevertheless, controversies exist for the grouping of ABC method and the intervals of gastroscopy surveillance for each group. In this review, we summarized these popular concerned topics for providing useful references to the healthcare practitioner in clinical practice. The PubMed databases were systematically searched from the inception dates to November 22, 2017, using the keywords "Helicobacter pylori," "Pepsinogens," and "Stomach Neoplasms." Original articles and reviews on the topics were selected. Anti-H. pylori antibody and serum PG concentration showed significant changes under the different status of H. pylori infection and the progression of atrophic gastritis, which can be used for risk stratification of gastric cancer in clinic. In addition, anti-H. pylori antibody titer can be used for further risk stratification of gastric cancer contributing to determine better endoscopy surveillance interval. The early detection and diagnosis of gastric cancer benefit from the risk stratification, but the cutoff values for H. pylori antibody and serum PG concentration require further modification.

High-throughput behavioral screening method for detecting auditory response defects in zebrafish.

PubMed

Bang, Pascal I; Yelick, Pamela C; Malicki, Jarema J; Sewell, William F

2002-08-30

We have developed an automated, high-throughput behavioral screening method for detecting hearing defects in zebrafish. Our assay monitors a rapid escape reflex in response to a loud sound. With this approach, 36 adult zebrafish, restrained in visually isolated compartments, can be simultaneously assessed for responsiveness to near-field 400 Hz sinusoidal tone bursts. Automated, objective determinations of responses are achieved with a computer program that obtains images at precise times relative to the acoustic stimulus. Images taken with a CCD video camera before and after stimulus presentation are subtracted to reveal a response to the sound. Up to 108 fish can be screened per hour. Over 6500 fish were tested to validate the reliability of the assay. We found that 1% of these animals displayed hearing deficits. The phenotypes of non-responders were further assessed with radiological analysis for defects in the gross morphology of the auditory system. Nearly all of those showed abnormalities in conductive elements of the auditory system: the swim bladder or Weberian ossicles. Copyright 2002 Elsevier Science B.V.

Development of a method for efficient cost-effective screening of Aspergillus niger mutants having increased production of glucoamylase.

PubMed

Zhu, Xudong; Arman, Bessembayev; Chu, Ju; Wang, Yonghong; Zhuang, Yingping

2017-05-01

To develop an efficient cost-effective screening process to improve production of glucoamylase in Aspergillus niger. The cultivation of A. niger was achieved with well-dispersed morphology in 48-deep-well microtiter plates, which increased the throughput of the samples compared to traditional flask cultivation. There was a close negative correlation between glucoamylase and its pH of the fermentation broth. A novel high-throughput analysis method using Methyl Orange was developed. When compared to the conventional analysis method using 4-nitrophenyl α-D-glucopyranoside as substrate, a correlation coefficient of 0.96 by statistical analysis was obtained. Using this novel screening method, we acquired a strain with an activity of 2.2 × 10 3  U ml -1 , a 70% higher yield of glucoamylase than its parent strain.

Aspen pectate lyase PtxtPL1-27 mobilizes matrix polysaccharides from woody tissues and improves saccharification yield

PubMed Central

2014-01-01

Background Wood cell walls are rich in cellulose, hemicellulose and lignin. Hence, they are important sources of renewable biomass for producing energy and green chemicals. However, extracting desired constituents from wood efficiently poses significant challenges because these polymers are highly cross-linked in cell walls and are not easily accessible to enzymes and chemicals. Results We show that aspen pectate lyase PL1-27, which degrades homogalacturonan and is expressed at the onset of secondary wall formation, can increase the solubility of wood matrix polysaccharides. Overexpression of this enzyme in aspen increased solubility of not only pectins but also xylans and other hemicelluloses, indicating that homogalacturonan limits the solubility of major wood cell wall components. Enzymatic saccharification of wood obtained from PL1-27-overexpressing trees gave higher yields of pentoses and hexoses than similar treatment of wood from wild-type trees, even after acid pretreatment. Conclusions Thus, the modification of pectins may constitute an important biotechnological target for improved wood processing despite their low abundance in woody biomass. PMID:24450583

Production of L- and D-lactic acid from waste Curcuma longa biomass through simultaneous saccharification and cofermentation.

PubMed

Nguyen, Cuong Mai; Kim, Jin-Seog; Nguyen, Thanh Ngoc; Kim, Seul Ki; Choi, Gyung Ja; Choi, Yong Ho; Jang, Kyoung Soo; Kim, Jin-Cheol

2013-10-01

Simultaneous saccharification and cofermentation (SSCF) of Curcuma longa waste biomass obtained after turmeric extraction to L- and D-lactic acid by Lactobacillus coryniformis and Lactobacillus paracasei, respectively, was investigated. This is a rich, starchy, agro-industrial waste with potential for use in industrial applications. After optimizing the fermentation of the biomass by adjusting nitrogen sources, enzyme compositions, nitrogen concentrations, and raw material concentrations, the SSCF process was conducted in a 7-l jar fermentor at 140 g dried material/L. The maximum lactic acid concentration, average productivity, reducing sugar conversion and lactic acid yield were 97.13 g/L, 2.7 g/L/h, 95.99% and 69.38 g/100 g dried material for L-lactic acid production, respectively and 91.61 g/L, 2.08 g/L/h, 90.53% and 65.43 g/100 g dried material for D-lactic acid production, respectively. The simple and efficient process described in this study could be utilized by C. longa residue-based lactic acid industries without requiring the alteration of plant equipment. Copyright © 2013 Elsevier Ltd. All rights reserved.

Simultaneous saccharification and fermentation of broken rice: an enzymatic extrusion liquefaction pretreatment for Chinese rice wine production.

PubMed

Li, Hongyan; Jiao, Aiquan; Xu, Xueming; Wu, Chunsen; Wei, Benxi; Hu, Xiuting; Jin, Zhengyu; Tian, Yaoqi

2013-08-01

Broken rice, pretreated by enzymatic extrusion liquefaction, was used to produce Chinese rice wine by simultaneous saccharification and fermentation (SSF) process in this study. The study compared the novel process and traditional process for Chinese rice wine fermentation utilizing broken rice and head rice, respectively. With the optimum extrusion parameters (barrel temperature, 98 °C; moisture content, 42% and amylase concentration, 1‰), 18% (v/v at 20 °C) alcoholic degree, 37.66% fermentation recovery and 93.63% fermentation efficiency were achieved, indicating enzymatic extrusion-processed rice wine from broken rice exhibited much higher fermentation rate and efficiency than traditional-processed rice wine from head rice during SSF. The starch molecule distribution data indicated that the alcoholic degree was related to the oligosaccharides' formation during enzymatic extrusion. Sum of amino acid (AA) in the extrusion-processed wine was 53.7% higher than that in the traditional one. These results suggest that the enzymatic extrusion pretreatment for broken rice is a feasible and alternative process in the fermentation of Chinese rice wine.

Simultaneous saccharification and fermentation of steam exploded duckweed: Improvement of the ethanol yield by increasing yeast titre.

PubMed

Zhao, X; Moates, G K; Elliston, A; Wilson, D R; Coleman, M J; Waldron, K W

2015-10-01

This study investigated the conversion of Lemna minor biomass to bioethanol. The biomass was pre-treated by steam explosion (SE, 210°C, 10 min) and then subjected to simultaneous saccharification and fermentation (SSF) using Cellic® CTec 2 (20 U or 0.87 FPU g(-1) substrate) cellulase plus β-glucosidase (2 U g(-1) substrate) and a yeast inoculum of 10% (v/v or 8.0×10(7) cells mL(-1)). At a substrate concentration of 1% (w/v) an ethanol yield of 80% (w/w, theoretical) was achieved. However at a substrate concentration of 20% (w/v), the ethanol yield was lowered to 18.8% (w/w, theoretical). Yields were considerably improved by increasing the yeast titre in the inoculum or preconditioning the yeast on steam exploded liquor. These approaches enhanced the ethanol yield up to 70% (w/w, theoretical) at a substrate concentration of 20% (w/v) by metabolising fermentation inhibitors. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Current and emerging screening methods to identify post-head-emergence frost adaptation in wheat and barley.

PubMed

Frederiks, T M; Christopher, J T; Harvey, G L; Sutherland, M W; Borrell, A K

2012-09-01

Cereal crops can suffer substantial damage if frosts occur at heading. Identification of post-head-emergence frost (PHEF) resistance in cereals poses a number of unique and difficult challenges. Many decades of research have failed to identify genotypes with PHEF resistance that could offer economically significant benefit to growers. Research and breeding gains have been limited by the available screening systems. Using traditional frost screening systems, genotypes that escape frost injury in trials due to spatial temperature differences and/or small differences in phenology can be misidentified as resistant. We believe that by improving techniques to minimize frost escapes, such 'false-positive' results can be confidently identified and eliminated. Artificial freezing chambers or manipulated natural frost treatments offer many potential advantages but are not yet at the stage where they can be reliably used for frost screening in breeding programmes. Here we describe the development of a novel photoperiod gradient method (PGM) that facilitates screening of genotypes of different phenology under natural field frosts at matched developmental stages. By identifying frost escapes and increasing the efficiency of field screening, the PGM ensures that research effort can be focused on finding genotypes with improved PHEF resistance. To maximize the likelihood of identifying PHEF resistance, we propose that the PGM form part of an integrated strategy to (i) source germplasm;(ii) facilitate high throughput screening; and (iii) permit detailed validation. PGM may also be useful in other studies where either a range of developmental stages and/or synchronized development are desired.

Benchmarking Data Sets for the Evaluation of Virtual Ligand Screening Methods: Review and Perspectives.

PubMed

Lagarde, Nathalie; Zagury, Jean-François; Montes, Matthieu

2015-07-27

Virtual screening methods are commonly used nowadays in drug discovery processes. However, to ensure their reliability, they have to be carefully evaluated. The evaluation of these methods is often realized in a retrospective way, notably by studying the enrichment of benchmarking data sets. To this purpose, numerous benchmarking data sets were developed over the years, and the resulting improvements led to the availability of high quality benchmarking data sets. However, some points still have to be considered in the selection of the active compounds, decoys, and protein structures to obtain optimal benchmarking data sets.

Cost-effectiveness analysis of population-based screening of hepatocellular carcinoma: Comparing ultrasonography with two-stage screening

PubMed Central

Kuo, Ming-Jeng; Chen, Hsiu-Hsi; Chen, Chi-Ling; Fann, Jean Ching-Yuan; Chen, Sam Li-Sheng; Chiu, Sherry Yueh-Hsia; Lin, Yu-Min; Liao, Chao-Sheng; Chang, Hung-Chuen; Lin, Yueh-Shih; Yen, Amy Ming-Fang

2016-01-01

AIM: To assess the cost-effectiveness of two population-based hepatocellular carcinoma (HCC) screening programs, two-stage biomarker-ultrasound method and mass screening using abdominal ultrasonography (AUS). METHODS: In this study, we applied a Markov decision model with a societal perspective and a lifetime horizon for the general population-based cohorts in an area with high HCC incidence, such as Taiwan. The accuracy of biomarkers and ultrasonography was estimated from published meta-analyses. The costs of surveillance, diagnosis, and treatment were based on a combination of published literature, Medicare payments, and medical expenditure at the National Taiwan University Hospital. The main outcome measure was cost per life-year gained with a 3% annual discount rate. RESULTS: The results show that the mass screening using AUS was associated with an incremental cost-effectiveness ratio of USD39825 per life-year gained, whereas two-stage screening was associated with an incremental cost-effectiveness ratio of USD49733 per life-year gained, as compared with no screening. Screening programs with an initial screening age of 50 years old and biennial screening interval were the most cost-effective. These findings were sensitive to the costs of screening tools and the specificity of biomarker screening. CONCLUSION: Mass screening using AUS is more cost effective than two-stage biomarker-ultrasound screening. The most optimal strategy is an initial screening age at 50 years old with a 2-year inter-screening interval. PMID:27022228

Bioethanol Production From Banana Stem By Using Simultaneous Saccharification and Fermentation (SSF)

NASA Astrophysics Data System (ADS)

Kusmiyati; Mustofa, A.; Jumarmi

2018-05-01

The rapid growth and development of industries in the world result in a greater energy needs. Some studies show that ethanol can be used as an alternative energy. However, bioethanol production from food raw materials such as sugar and starch has drawback that cause the food crisis. This aim of this study was to convert banana stem into bioethanol. Banana stem contained of 44.6% cellulose, 36.0% hemicellulose and 19.4% lignin. After banana stems were pretreated with acid (H2SO4) and alkaline (NaOH) at a concentration of 2% w/v at 121 °C for 30 minutes, then subsequently the simultaneous saccharification and fermentation (SSF) were carried out by using mixed cultures of Aspergillus niger, Trichoderma reesei and Zymomonas mobilis at various enzymes ratios of (1:1:1), (1:2:1), (1:2:2), (1:1:2) and various pH (4, 5 and 6) with SSF time for 144 hours and temperature of 30°C. The results show that acid pretreatment showed better results than the alkali pretreatment. After acid pretreatment and alkali pretreatment, lignin content of pretreted banana stem reduced to 15.92% and 16.34%, respectively, cellulose increased to 52.11% and 50.6% respectively, hemicellulose reduced to 28.45% and 28.83%, respectively The SSF showed that pH 5 gave the highest bioethanol. The highest concentration of bioethanol (8.51 g/L) was achieved at the SSF process at pH 5 with a ratio Aspergillus niger, Trichoderma reesei and Zymomonas mobilis enzymes of (1:1:2).

Interlaboratory validation of quantitative duplex real-time PCR method for screening analysis of genetically modified maize.

PubMed

Takabatake, Reona; Koiwa, Tomohiro; Kasahara, Masaki; Takashima, Kaori; Futo, Satoshi; Minegishi, Yasutaka; Akiyama, Hiroshi; Teshima, Reiko; Oguchi, Taichi; Mano, Junichi; Furui, Satoshi; Kitta, Kazumi

2011-01-01

To reduce the cost and time required to routinely perform the genetically modified organism (GMO) test, we developed a duplex quantitative real-time PCR method for a screening analysis simultaneously targeting an event-specific segment for GA21 and Cauliflower Mosaic Virus 35S promoter (P35S) segment [Oguchi et al., J. Food Hyg. Soc. Japan, 50, 117-125 (2009)]. To confirm the validity of the method, an interlaboratory collaborative study was conducted. In the collaborative study, conversion factors (Cfs), which are required to calculate the GMO amount (%), were first determined for two real-time PCR instruments, the ABI PRISM 7900HT and the ABI PRISM 7500. A blind test was then conducted. The limit of quantitation for both GA21 and P35S was estimated to be 0.5% or less. The trueness and precision were evaluated as the bias and reproducibility of the relative standard deviation (RSD(R)). The determined bias and RSD(R) were each less than 25%. We believe the developed method would be useful for the practical screening analysis of GM maize.

Discovery of potent KIFC1 inhibitors using a method of integrated high-throughput synthesis and screening.

PubMed

Yang, Bin; Lamb, Michelle L; Zhang, Tao; Hennessy, Edward J; Grewal, Gurmit; Sha, Li; Zambrowski, Mark; Block, Michael H; Dowling, James E; Su, Nancy; Wu, Jiaquan; Deegan, Tracy; Mikule, Keith; Wang, Wenxian; Kaspera, Rüdiger; Chuaqui, Claudio; Chen, Huawei

2014-12-11

KIFC1 (HSET), a member of the kinesin-14 family of motor proteins, plays an essential role in centrosomal bundling in cancer cells, but its function is not required for normal diploid cell division. To explore the potential of KIFC1 as a therapeutic target for human cancers, a series of potent KIFC1 inhibitors featuring a phenylalanine scaffold was developed from hits identified through high-throughput screening (HTS). Optimization of the initial hits combined both design-synthesis-test cycles and an integrated high-throughput synthesis and biochemical screening method. An important aspect of this integrated method was the utilization of DMSO stock solutions of compounds registered in the corporate compound collection as synthetic reactants. Using this method, over 1500 compounds selected for structural diversity were quickly assembled in assay-ready 384-well plates and were directly tested after the necessary dilutions. Our efforts led to the discovery of a potent KIFC1 inhibitor, AZ82, which demonstrated the desired centrosome declustering mode of action in cell studies.

Accessibility of standardized information of a national colorectal cancer screening program for low health literate screening invitees: A mixed method study.

PubMed

Fransen, Mirjam P; Dekker, Evelien; Timmermans, Daniëlle R M; Uiters, Ellen; Essink-Bot, Marie-Louise

2017-02-01

To explore the accessibility of standardized printed information materials of the national Dutch colorectal cancer screening program among low health literate screening invitees and to assess the effect of the information on their knowledge about colorectal cancer and the screening program. Linguistic tools were used to analyze the text and design characteristics. The accessibility, comprehensibility and relevance of the information materials were explored in interviews and in observations (n=25). The effect of the information on knowledge was assessed in an online survey (n=127). The materials employed a simple text and design. However, respondents expressed problems with the amount of information, and the difference between screening and diagnostic follow-up. Knowledge significantly increased in 10 out of 16 items after reading the information but remained low for colorectal cancer risk, sensitivity of testing, and the voluntariness of colorectal cancer screening. Despite intelligible linguistic and design characteristics, screening invitees with low health literacy had problems in accessing, comprehending and applying standard information materials on colorectal cancer screening, and lacked essential knowledge for informed decision-making about participation. To enable equal access to informed decision-making, information strategies need to be adjusted to the skills of low health literate screening invitees. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Diabetic retinopathy screening: global and local perspective.

PubMed

Gangwani, R A; Lian, J X; McGhee, S M; Wong, D; Li, K Kw

2016-10-01

Diabetes mellitus has become a global epidemic. It causes significant macrovascular complications such as coronary artery disease, peripheral artery disease, and stroke; as well as microvascular complications such as retinopathy, nephropathy, and neuropathy. Diabetic retinopathy is known to be the leading cause of blindness in the working-age population and may be asymptomatic until vision loss occurs. Screening for diabetic retinopathy has been shown to reduce blindness by timely detection and effective laser treatment. Diabetic retinopathy screening is being done worldwide either as a national screening programme or hospital-based project or as a community-based screening programme. In this article, we review different methods of screening including grading used to detect the severity of sight-threatening retinopathy and the newer screening methods. This review also includes the method of systematic screening being carried out in Hong Kong, a system that has helped to identify diabetic retinopathy among all attendees in public primary care clinics using a Hong Kong-wide public patients' database.

Microplate-based method to screen inhibitors of isozymes of cyclic nucleotide phosphodiesterase fused to SUMO.

PubMed

Chen, Chunyan; Liu, Miaomiao; Wu, Jing; Yang, Xiaolan; Hu, Xiaolei; Pu, Jun; Long, Gaobo; Xie, Yanling; Jiang, Hairong; Yuan, Yonghua; Liao, Fei

2014-12-01

The feasibility for microplate-based screening of inhibitors of isozymes of cyclic nucleotide phosphodiesterase (PDE) was tested via the coupled action of a phosphatase on adenosine-5'-monophosphate and an improved malachite green assay of phosphate. Human full-length PDE4B2 and truncated mutant (152-528aa) were expressed in Escherichia coli via fusion to SUMO, which after purification through Ni-NTA column exhibited specific activities >0.017 U mg(-1). In the presence of proteins <30 mg L(-1), absorbance for 10 µΜ phosphate was measurable; a PDE isozyme of specific activity over 0.008 U mg(-1) after reaction for 20 min thus suited for microplate-based screening of inhibitors. By using Biotek ELX 800 microplate reader, affinities of two forms of PEDE4B2 for cAMP, rolipram and papaverine varied over three magnitudes and were consistent with those by routine assay, respectively. Hence, the proposed method was promising for high-throughput-screening of inhibitors of phosphate-releasing enzymes bearing specific activities over 0.008 U mg(-1).

Robust Microplate-Based Methods for Culturing and in Vivo Phenotypic Screening of Chlamydomonas reinhardtii