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1.
The present work presents an alternative approach to ethanol production from sweet sorghum: without detoxification, acid-impregnated
fresh sweet sorghum stem which contains soluble (glucose and sucrose) and insoluble carbohydrates (cellulose and hemicellulose)
was steam pretreated under mild temperature of 100 °C. Simultaneous saccharification and fermentation experiments were performed
on the pretreated slurries using Saccharomyces cerevisiae. Experimentally, ground fresh sweet sorghum stem was combined with H2SO3 at dosages of 0.25, 0.50, and 0.75 g/g dry matter (DM) and steam pretreated by varying the residence time (60, 120, or 240 min).
According to enzymatic hydrolysis results and ethanol yields, H2SO3 was a powerful and mild acid for improving enzymatic digestibility of sorghum stem. At a solid loading of 10% (w/v) and acid dosage of 0.25 g/g DM H2SO3 at 100 °C for 120 min, 44.5 g/L ethanol was obtained after 48 ± 4 h of simultaneous saccharification and fermentation. This
corresponded to an overall ethanol yield of 110% of the theoretical one, based on the soluble carbohydrates in the fresh sweet
sorghum stem. The concentrations of hydroxymethylfurfural and furfural of the sulfurous acid pretreated samples were below
0.4 g/L. Ethanol would not inhibit the cellulase activity, at least under the concentration of 34 g/L. 相似文献
2.
Youngran Kim Anna Yu Minhee Han Gi-wook Choi Bongwoo Chung 《Applied biochemistry and biotechnology》2011,163(1):143-152
The fermentable sugars in lignocellulosic biomass are derived from cellulose and hemicellulose, which are not readily accessible
to enzymatic saccharification because of their recalcitrance. An ethanosolv pretreatment method was applied for the enzymatic
saccharification of barley straw with an inorganic acid. The effects of four process variables (temperature, time, catalyst
dose, and ethanol concentration) on the barley straw pretreatment were analyzed over a broad range using a small composite
design and a response surface methodology. The yield of the residual solid and composition of the solid fraction differed
as ethanosolv conditions varied within the experimental range. A glucan recovery, xylan recovery, and delignification were
85%, 14%, and 69% at center point conditions (170°C, 60 min, 1.0% (w/w) H2SO4, and 50% (w/w) ethanol), respectively. Ethanosolv pretreatment removed lignin effectively. Additionally, the highest enzymatic digestibility
of 85.3% was obtained after 72 h at center point conditions. 相似文献
3.
A novel process using chemical, thermal, and enzymatic treatment for conversion of hulled barley into fermentable sugars was
developed. The purpose of this process is to convert both lignocellulosic polysaccharides and starch in hulled barley grains
into fermentable sugars simultaneously without a need for grinding and hull separation. In this study, hulled barley grains
were treated with 0.1 and 1.0 wt.-% sulfuric acid at various temperatures ranging from 110 to 170 °C in a 63-ml flow-through
packed-bed stainless steel reactor. After sulfuric acid pretreatment, simultaneous conversion of lignocellulose and starch
in the barley grains into fermentable sugars was performed using an enzyme cocktail, which included α-amylase, glucoamylase,
cellulase, and β-glucosidase. Both starch and non-starch polysaccharides in the pre-treated barley grains were readily converted
to fermentable sugars. The treated hulled barley grains, including their hull, were completely hydrolyzed to fermentable sugars
with recovery of almost 100% of the available glucose and xylose. The pretreatment conditions of this chemical, thermal, and
enzymatic (CTE) process for achieving maximum yield of fermentable sugars were 1.0 wt.% sulfuric acid and 110 °C. In addition
to starch, the acid pretreatment also retained most of the available proteins in solid form, which is essential for subsequent
production of fuel ethanol and high protein distiller’s dried grains with solubles co-product. 相似文献
4.
《印度化学会志》2021,98(12):100264
After harvesting season, large amounts of durian peels were produced and uselessly disposed of by combustion or landfilling leading to environmental pollution and human health hazards. Proper management of these wastes is necessary to reduce not only an environmental problem but also to create value-added products. Herein, we optimized sulfuric acid pretreatment to promote enzymatic saccharification of durian peels and convert fermentable sugars to bioethanol. Three pretreatment parameters were optimized based on Response Surface Methodology (RSM), including acid concentration (0.5%–3.5%), temperature (60–140 °C), and time (20–100 min). At optimal pretreatment condition using 2.75% H2SO4, at 127.14 °C for 74.13 min, 0.53 g/g-biomass of reducing sugars were produced, which is 1.88 folds higher than the untreated durian peel. The pretreatment liquor and biomass hydrolysate were analyzed by Gas Chromatograph-Mass spectrometer (GC-MS), and fermentation inhibitors, i.e. acetic acid, furfural, and furan methanol, were identified in those fractions. Due to pretreatment at the optimal condition, a higher yield of reducing sugar was observed, and the production of ethanol from the pretreated biomass was 5.70 g/L (equivalent to 87.43% of theoretical yields). These findings demonstrated the potential of using durian waste in the biorefinery concept to achieve a concept of the green economy. 相似文献
5.
Pretreatment and enzymatic saccharification of corn fiber 总被引:14,自引:0,他引:14
Corn fiber consists of about 20% starch, 14% cellulose, and 35% hemicellulose, and has the potential to serve as a low-cost
feedstock for production of fuel ethanol. Several pretreatments (hot water, alkali, and dilute, acid) and enzymatic saccharification
procedures were evaluated for the conversion of corn fiber starch, cellulose, and hemicellulose to monomeric sugars. Hot water
pretreatment (121°C, 1 h) facilitated the enzymatic sacch arification of starch and cellulose but not hemicellulose. Hydrolysis
of corn fiber pretreated with alkali un dersimilar conditions by enzymatic means gave similar results. Hemicellulose and starch
components were converted to monomeric sugars by dilute H2SO4 pretreatment (0.5–1.0%, v/v) at 121°C. Based on these findings, a method for pretreatment and enzymatic saccharification
of corn fiber is presented. It in volves the pretreatment of corn fiber (15% solid, w/v) with dilute acid (0.5% H2SO4, v/v) at 121°C for 1 h, neutralization to pH 5.0, then saccharification of the pretreated corn fiber material with commercial
cellulase and β-glucosidase preparations The yield of monomeric sugars from corn fiber was typically 85–100% of the theoretical
yield.
Names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard
of the product, and the use of the name by USDA implies no approval of the product to the exclusion of others that may also
be suitable. 相似文献
6.
Rodrigues TH Rocha MV de Macedo GR Gonçalves LR 《Applied biochemistry and biotechnology》2011,164(6):929-943
In this work, the potential of microwave-assisted alkali pretreatment in order to improve the rupture of the recalcitrant
structures of the cashew able bagasse (CAB), lignocellulosic by-product in Brazil with no commercial value, is obtained from
cashew apple process to juice production, was studied. First, biomass composition of CAB was determined, and the percentage
of glucan and lignin was 20.54 ± 0.70% and 33.80 ± 1.30%, respectively. CAB content in terms of cellulose, hemicelluloses,
and lignin, 19.21 ± 0.35%, 12.05 ± 0.37%, and 38.11 ± 0.08%, respectively, was also determined. Results showed that, after
enzymatic hydrolysis, alkali concentration exerted influence on glucose formation, after pretreatment with 0.2 and 1.0 mo L−1 of NaOH (372 ± 12 and 355 ± 37 mg gglucan−1) when 2% (w/v) of cashew apple bagasse pretreated by microwave-assisted alkali pretreatment (CAB-M) was used. On the other hand, pretreatment
time (15–30 min) and microwave power (600–900 W) exerted no significant effect on hydrolysis. On enzymatic hydrolysis step,
improvement on solid percentage (16% w/v) and enzyme load (30 FPU gCAB-M−1) increased glucose concentration to 15 g L−1. The fermentation of the hydrolyzate by Saccharomyces cerevesiae resulted in ethanol concentration and productivity of 5.6 g L−1 and 1.41 g L−1 h−1, respectively. 相似文献
7.
Jian Zhang Wen-Xue Zhang Jian Yang Yue-Hong Liu Xia Zhong Zheng-Yun Wu Kenji Kida Yu Deng 《Applied biochemistry and biotechnology》2012,166(7):1856-1870
Ethanol conversion from rice straw using butanone and acetaldehyde dilute solution explosions was evaluated based on the optimization
of pure water explosion. To decrease residual inhibitor content, the exploded slurry was dried and investigated at different
temperature. Using a 0.9-mol/L butanone solution explosion, with the explosion pressure set at 3.1 MPa, the residence time
at 7 min, the dried rice straw-to-water ratio at 1:3 (w/w), and the exploded slurry drying temperuture at 90 °C for 8 h, the yields of total sugar, glucose, and xylose were 85%, 88%,
82% (w/w), respectively, and the ethanol productivity was 26.0 g/100 g rice straw dry matter. Moreover, 0.5-mol/L acetaldehyde dilute
solution explosion improved the efficiency of enzymatic hydrolysis (EH) and simultaneous saccharification and co-fermentation
(SSCF), and the residual inhibitors had negligible effects on EH and SSCF after detoxification by drying. The results suggested
that compared with pure water explosions, the use of butanone and of acetaldehyde dilute solution explosions lowered the explosive
temperature and improved the sugar yield, although relative crystallinity of the rice straw dry matter was increased after
the explosion. 相似文献
8.
Pretreatment of Rice Straw by a Hot-Compressed Water Process for Enzymatic Hydrolysis 总被引:1,自引:0,他引:1
Guoce Yu Shinichi Yano Hiroyuki Inoue Seiichi Inoue Takashi Endo Shigeki Sawayama 《Applied biochemistry and biotechnology》2010,160(2):539-551
Hot-compressed water (HCW) is among several cost-effective pretreatment processes of lignocellulosic biomass for enzymatic
hydrolysis. The present work investigated the characteristics of HCW pretreatment of rice straw including sugar production
and inhibitor formation in the liquid fraction and enzymatic hydrolysis of pretreated material. Pretreatment was carried out
at a temperature ranging from 140 to 240 °C for 10 or 30 min. Soluble oligosaccharides were found to constitute almost all
the components of total sugars in the liquid fraction. The maximal production of total glucose at 180 °C and below accounted
for 4.4–4.9% of glucan in raw material. Total xylose production peaked at 180 °C, accounting for 43.3% of xylan in raw material
for 10-min pretreatment and 29.8% for 30-min pretreatment. The production of acetic acid increased at higher temperatures
and longer treatment time, indicating more significant disruption of lignocellulosic structure, and furfural production achieved
the maximum (2.8 mg/ml) at 200 °C for both 10-min and 30-min processes. The glucose yield by enzymatic hydrolysis of pretreated
rice straw was no less than 85% at 180 °C and above for 30-min pretreatment and at 200 °C and above for 10-min pretreatment.
Considering sugar recovery, inhibitor formation, and process severity, it is recommended that a temperature of 180 °C for
a time of 30 min can be the most efficient process for HCW pretreatment of rice straw. 相似文献
9.
Statistical Optimization of Recycled-Paper Enzymatic Hydrolysis for Simultaneous Saccharification and Fermentation Via Central Composite Design 总被引:1,自引:0,他引:1
Qing Liu Ke-ke Cheng Jian-an Zhang Jin-ping Li Ge-hua Wang 《Applied biochemistry and biotechnology》2010,160(2):604-612
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 °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. 相似文献
10.
Ruiz HA Ruzene DS Silva DP da Silva FF Vicente AA Teixeira JA 《Applied biochemistry and biotechnology》2011,164(5):629-641
The present work describes the delignification of wheat straw through an environmentally friendly process resulting from sequential
application of autohydrolysis and organosolv processes. Wheat straw autohydrolysis was performed at 180°C during 30 min with
a liquid–solid ratio of 10 (v/w); under these conditions, a solubilization of 44% of the original xylan, with 78% of sugars as xylooligosaccharides of the
sum of sugars solubilized in the autohydrolysis liquors generated by the hemicellulose fraction hydrolysis. The corresponding
solid fraction enrichment with 63.7% of glucan and 7.55% of residual xylan was treated with a 40% ethanol and 0.1% NaOH aqueous
solution at a liquid–solid ratio of 10 (v/w), with the best results obtained at 180°C during 20 min. The highest lignin recovery, measured by acid precipitation of the
extracted lignin, was 3.25 g/100 ml. The lignin obtained by precipitation was characterized by FTIR, and the crystallinity
indexes from the native cellulose, the cellulose recovered after autohydrolysis, and the cellulose obtained after applying
the organosolv process were obtained by X-ray diffraction, returning values of 21.32%, 55.17%, and 53.59%, respectively. Visualization
of the fibers was done for all the processing steps using scanning electron microscopy. 相似文献
11.
Ethanol production from steam-explosion pretreated wheat straw 总被引:1,自引:0,他引:1
Ignacio Ballesteros Ma José Negro José Miguel Oliva Araceli Cabañas Paloma Manzanares Mercedes Ballesteros 《Applied biochemistry and biotechnology》2006,130(1-3):496-508
Bioconversion of cereal straw to bioethanol is becoming an attractive alternative to conventional fuel ethanol production
from grains. In this work, the best operational conditions for steam-explosion pretreatment of wheat straw for ethanol production
by a simultaneous saccharification and fermentation process were studied, using diluted acid [H2SO4 0.9% (w/w)] and water as preimpregnation agents. Acid-or water-impregnated biomass was steam-exploded at different temperatures
(160–200°C) and residence times (5, 10, and 20 min). Composition of solid and filtrate obtained after pretreatment, enzymatic
digestibility and ethanol production of pretreated wheat straw at different experimental conditions was analyzed. The best
pretreatment conditions to obtain high conversion yield to ethanol (approx 80% of theoretical) of cellulose-rich residue after
steam-explosion were 190°C and 10 min or 200°C and 5 min, in acid-impregnated straw. However, 180°C for 10 min in acid-impregnated
biomass provided the highest ethanol yield referred to raw material (140 L/t wheat straw), and sugars recovery yield in the
filtrate (300 g/kg wheat straw). 相似文献
12.
Apichai Santalad Supalax Srijaranai Rodjana Burakham Jeremy D. Glennon Richard L. Deming 《Analytical and bioanalytical chemistry》2009,394(5):1307-1317
A cloud-point extraction (CPE) method using Triton X-114 non-ionic surfactant was developed for the extraction and preconcentration
of carbamate insecticide residues (i.e., methomyl, propoxur, carbofuran, carbaryl, isoprocarb, and promecarb) in fruit samples.
The optimum conditions of CPE were 1.5% (w/v) Triton X-114, 7.0% (w/v) NaCl and 20 min equilibrated at 45 °C. The surfactant-rich phase was then analyzed by reversed-phase high-performance liquid
chromatography with ultraviolet detection at 270 nm, under gradient separation using methanol and 0.1% (v/v) acetic acid. Under the study conditions, six carbamate insecticides were successfully separated within 27 min. Good reproducibility
was obtained with the relative standard deviation of <3% for retention time and <9% for peak area. Limits of detection in
the studied fruit samples were in the range of 0.1–1.0 mg kg−1. No carbamate insecticides were detected in the studied fruit samples. The high recoveries of the spiked fruit samples were
obtained in the range 80.0–107%. The CPE method has been shown to be a potential useful methodology for the preconcentration
of the target analytes, with a preconcentration factor of 14. Moreover, the method is simple, has high sensitivity, consumes
much less solvent than traditional methods, and is environmental friendly. 相似文献
13.
Jeong YS Na HB Kim SK Kim YH Kwon EJ Kim J Yun HD Lee JK Kim H 《Applied biochemistry and biotechnology》2012,166(5):1328-1339
A gene encoding an extracellular xylanase was cloned from a compost metagenomic library. The xylanase gene, xyn10J, was 1,137 bp in length and was predicted to encode a protein of 378 amino acid residues with a putative signal peptide
of 27 amino acid residues. The molecular mass of the mature Xyn10J was calculated to be 39,882 Da with a pI of 6.09. Xyn10J
had a motif GVKVHFTEMDI characteristic of most members of glycosyl hydrolase family 10. The amino acid sequence of Xyn10J
showed 60.0% identity to that of XynH, a xylanase from an uncultured soil bacterium and 55% identity to XylC of Cellvibrio mixtus. Site-directed mutagenesis of the expected active site based on the sequence analysis indicated that an aspartic acid residue
(Asp207), in addition to the identified catalytic residues Glu165 and Glu270, plays a crucial role for the catalytic activity.
The purified Xyn10J had a mass of about 40 kDa and was optimally active at pH 7.0 and 40 °C. Xyn10J hydrolyzed beechwood xylan > birchwood
xylan > oat spelt xylan > arabinoxylan. Xyn10J hydrolyzed xylotetraose and xylohexaose exclusively to xylobiose, xylopentaose,
and xylotriose mainly to xylobiose with transglycosylation activity. The saccharification of reed (Phragmites communis) powder by commercial enzymes was significantly increased by the addition of a small amount of Xyn10J to the commercial preparation.
Xyn10J is the first xylanase screened directly from a compost metagenomic library, and the enzyme has the potential to be
used in the conversion of biomass to fermentable sugars for biofuel production. 相似文献
14.
Andre Ricardo de Lima Damásio Tony Márcio da Silva Alexandre Maller Jo?o Atílio Jorge Hector Francisco Terenzi Maria de Lourdes Teixeira de Moraes Polizeli 《Applied biochemistry and biotechnology》2010,160(5):1496-1507
An extracellular polygalacturonase (PG) produced from Paecilomyces variotii was purified to homogeneity through two chromatography steps using DEAE-Fractogel and Sephadex G-100. The molecular weight
of P. variotii PG was 77,300 Da by gel filtration and SDS-PAGE. PG had isoelectric point of 4.37 and optimum pH 4.0. PG was very stable
from pH 3.0 to 6.0. The extent of hydrolysis of different pectins by the purified enzyme was decreased with an increase in
the degree of esterification. PG had no activity toward non-pectic polysaccharides. The apparent K
m and V
max values for hydrolyzing sodium polypectate were 1.84 mg/mL and 432 μmol/min/mg, respectively. PG was found to have temperature
optimum at 65 °C and was totally stable at 45 °C for 90 min. Half-life at 55 °C was 50.6 min. Almost all the examined metal
cations showed partial inhibitory effects under enzymatic activity, except for Na+1, K+1, and Co+2 (1 mM) and Cu+2 (1 and 10 mM). 相似文献
15.
Luisa Maurelli Elena Ionata Francesco La Cara Alessandra Morana 《Applied biochemistry and biotechnology》2013,170(5):1104-1118
Chestnut shell (CS) is an agronomic residue mainly used for extraction of antioxidants or as adsorbent of metal ions. It also contains some polysaccharide that has not been considered as potential source of fermentable sugars for biofuel production until now. In this study, the effect of different pretreatment methods on CS was evaluated in order to obtain the greatest conversion of cellulose and xylan into fermentable sugars. Hot acid impregnation, steam explosion (acid-catalysed or not), and aqueous ammonia soaking (AAS) were selected as pretreatments. The pretreated biomass was subjected to saccharification with two enzyme cocktails prepared from commercial preparations, and evaluation of the best pretreatment and enzyme cocktail was based on the yield of fermentable sugars produced. As AAS provided the best result after preliminary experiments, enhancement of sugar production was attempted by changing the concentrations of ammonium hydroxide, enzymes, and CS. The optimal pretreatment condition was 10 % ammonium hydroxide, 70 °C, 22 h with CS at 5 % solid loading. After saccharification of the pretreated CS for 72 h at 50 °C and pH 5.0 with a cocktail containing cellulase (Accellerase 1500), beta-glucosidase (Accellerase BG), and xylanase (Accellerase XY), glucose and xylose yields were 67.8 and 92.7 %, respectively. 相似文献
16.
Daniela de Araújo Viana Carolina de Albuquerque Lima Rejane Pereira Neves Cristina Souza Mota Keila Aparecida Moreira José Luiz de Lima-Filho Maria Taciana Holanda Cavalcanti Attilio Converti Ana Lúcia Figueiredo Porto 《Applied biochemistry and biotechnology》2010,162(3):830-842
Cow raw milk from dairy cooperatives was examined for its microbial composition. Among the isolates identified, 17.6% were
yeasts. The most frequent genus was Candida, although members belonging to the genera Brettanomyces, Dekkera, and Geotricum were also identified. Although qualitative and quantitative tests for extracellular proteolytic activity were positive for
all the species isolated, Candida buinensis showed the highest response (23.5 U/mg); therefore, it was selected for subsequent investigation. The results of fermentations
carried out at variable temperature, pH, and soybean flour concentration, according to a 23 full factorial design, demonstrated that this yeast ensured the highest production of extracellular proteases (573 U/mL)
when cultivated at 35 °C, pH 6.5, and using soybean flour concentrations in the range 0.1–0.5% (w/v). The cell-free supernatants showed the highest activity at 25 °C and pH 7.0, and satisfactory stability in the ranges 25–30 °C
and pH 7–9. The first-order rate constants of protease inactivation in the cell-free supernatants were calculated at different
temperatures from semi-log plots of the residual activity versus time and then used in Arrhenius and Eyring plots to estimate
the main thermodynamic parameters of thermoinactivation (E* = 40.0 kJ/mol; ΔH* = 37.3 kJ/mol; ΔS* = −197.5 J/mol K; ΔG* = 101 kJ/mol). 相似文献
17.
Moreira MM Morais S Barros AA Delerue-Matos C Guido LF 《Analytical and bioanalytical chemistry》2012,403(4):1019-1029
This paper reports a novel application of microwave-assisted extraction (MAE) of polyphenols from brewer’s spent grains (BSG).
A 24 orthogonal composite design was used to obtain the optimal conditions of MAE. The influence of the MAE operational parameters
(extraction time, temperature, solvent volume and stirring speed) on the extraction yield of ferulic acid was investigated
through response surface methodology. The results showed that the optimal conditions were 15 min extraction time, 100 °C extraction
temperature, 20 mL of solvent, and maximum stirring speed. Under these conditions, the yield of ferulic acid was 1.31 ± 0.04%
(w/w), which was fivefold higher than that obtained with conventional solid–liquid extraction techniques. The developed new extraction
method considerably reduces extraction time, energy and solvent consumption, while generating fewer wastes. HPLC-DAD-MS analysis
indicated that other hydroxycinnamic acids and several ferulic acid dehydrodimers, as well as one dehydrotrimer were also
present, confirming that BSG is a valuable source of antioxidant compounds. 相似文献
18.
Macwan JS Ionita IA Dostalek M Akhlaghi F 《Analytical and bioanalytical chemistry》2011,400(2):423-433
The aim of the proposed work was to develop and validate a simple and sensitive assay for the analysis of atorvastatin (ATV)
acid, ortho- and para-hydroxy-ATV, ATV lactone, and ortho- and para-hydroxy-ATV lactone in human plasma using liquid chromatography-tandem mass spectrometry. All six analytes and corresponding
deuterium (d5)-labeled internal standards were extracted from 50 μL of human plasma by protein precipitation. The chromatographic
separation of analytes was achieved using a Zorbax-SB Phenyl column (2.1 mm × 100 mm, 3.5 μm). The mobile phase consisted
of a gradient mixture of 0.1% v/v glacial acetic acid in 10% v/v methanol in water (solvent A) and 40% v/v methanol in acetonitrile (solvent B). All analytes including ortho- and para-hydroxy metabolites were baseline-separated within 7.0 min using a flow rate of 0.35 mL/min. Mass spectrometry detection was
carried out in positive electrospray ionization mode, with multiple-reaction monitoring scan. The calibration curves for all
analytes were linear (R
2 ≥ 0.9975, n = 3) over the concentration range of 0.05–100 ng/mL and with lower limit of quantitation of 0.05 ng/mL. Mean extraction recoveries
ranged between 88.6–111%. Intra- and inter-run mean percent accuracy were between 85–115% and percent imprecision was ≤ 15%.
Stability studies revealed that ATV acid and lactone forms were stable in plasma during bench top (6 h on ice-water slurry),
at the end of three successive freeze and thaw cycles and at −80 °C for 3 months. The method was successfully applied in a
clinical study to determine concentrations of ATV and its metabolites over 12 h post-dose in patients receiving atorvastatin. 相似文献
19.
Divanery Rodriguez-Gomez Linda Lehmann Nadja Schultz-Jensen Anne Belinda Bjerre Timothy John Hobley 《Applied biochemistry and biotechnology》2012,166(8):2051-2063
Plasma-assisted pretreated wheat straw was investigated for cellulase and xylanase production by Trichoderma reesei fermentation. Fermentations were conducted with media containing washed and unwashed plasma-assisted pretreated wheat straw
as carbon source which was sterilized by autoclavation. To account for any effects of autoclavation, a comparison was made
with unsterilized media containing antibiotics. It was found that unsterilized washed plasma-assisted pretreated wheat straw
(which contained antibiotics) was best suited for the production of xylanases (110 IU ml−1) and cellulases (0.5 filter paper units (FPU) ml−1). Addition of Avicel boosted enzyme titers with the highest cellulase titers (1.5 FPU ml−1) found with addition of 50 % w/w Avicel and with the highest xylanase production (350 IU ml−1) reached in the presence of 10 % w/w Avicel. Comparison with enzyme titers from other nonrefined feedstocks suggests that plasma pretreated wheat straw is a promising
and suitable substrate for cellulase and hemicellulase production. 相似文献
20.
A simple and sensitive assay was developed and validated for the simultaneous quantification of rosuvastatin acid (RST), rosuvastatin-5S-lactone (RST-LAC), and N-desmethyl rosuvastatin (DM-RST), in buffered human plasma using liquid chromatography–tandem mass spectrometry (LC-MS/MS).
All the three analytes and the corresponding deuterium-labeled (d6) internal standards were extracted from 50 μL of buffered
human plasma by protein precipitation. The analytes were chromatographically separated using a Zorbax-SB Phenyl column (2.1 mm × 100 mm,
3.5 μm). The mobile phase comprised of a gradient mixture of 0.1% v/v glacial acetic acid in 10% v/v methanol in water (solvent A) and 40% v/v methanol in acetonitrile (solvent B). The analytes were separated at baseline within 6.0 min using a flow rate of 0.35 mL/min.
Mass spectrometry detection was carried out in positive electrospray ionization mode. The calibration curves for all three
analytes were linear (R ≥ 0.9964, n = 3) over the concentration range of 0.1–100 ng/mL for RST and RST-LAC, and 0.5–100 ng/mL for DM-RST. Mean extraction recoveries
ranged within 88.0–106%. Intra- and inter-run mean percent accuracy were within 91.8–111% and percent imprecision was ≤15%.
Stability studies revealed that all the analytes were stable in matrix during bench-top (6 h on ice–water slurry), at the
end of three successive freeze and thaw cycles and at −80°C for 1 month. The method was successfully applied in a clinical
study to determine the concentrations of RST and the lactone metabolite over 12-h post-dose in patients who received a single
dose of rosuvastatin. 相似文献