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1.
《Applied biochemistry and biotechnology》1996,131(1-3):738-750
The corn wet milling process produces a 10% (w/w of the processed corn) byproduct called corn fiber, which is utilized worldwide
as a low-value feedstock for cattle. The aim of this study was to find a higher value use of corn fiber. The main fractions
of corn fiber are: 20% starch, 40% hemicellulose, 14% cellulose, and 14% protein. Extraction of the highly valuable, cholesterol-lowering
corn fiber oil is not feasible owing to its low (2% w/w) concentration in the fiber. The developed technology is based on
simple and inexpensive procedures, like washing with hot water, dilute acid hydrolysis at 120°C, enzymatic hydrolysis of cellulose,
screening, drying, and extraction. The main fractions are sharply separated in the order of starch, hemicellulose, cellulose,
lipoprotein, and lignin). The lipoprotein fraction adds up to 10% of the original dry corn fiber, and contains 45% corn fiber
oil, thus yielding more oil than direct extraction of the fiber. It is concluded that the defined method makes the extraction
of the corn fiber oil economically feasible. The fractionation process also significantly increases the yield of cholesterol-lowering
substances (sterols and sterolesters). At the same time clear and utilizable fractions of monosaccharides, protein, and lignin
are produced. 相似文献
2.
Xin-Liang Li Bruce S. Dien Michael A. Cotta Y. Victor Wu Badal C. Saha 《Applied biochemistry and biotechnology》2005,121(1-3):321-334
Corn fiber is the fibrous by-product of wet-mill corn processing. It typically consists of about 20% starch, 14% cellulose,
and 30% hemicellulose in the form of arabinoxylan. Crude corn fiber (CCF) was fractionated into de-starched corn fiber (DSCF),
corn fiber with cellulose (CFC) enriched, and corn fiber arabinoxylan (CFAX), and these fractions were evaluated as substrates
for enzyme production by Trichoderma reesei. T. reesei QM9414 and Rut C-30 grew on CCF, DSCF, CFC, or CFAX and secreted a number of hydrolytic enzymes. The enzymes displayed synergism
with commercial cellulases for corn fiber hydrolysis.
Mention of trade names or commercial products in this article is solely for the purpose of providing specific information
and does not imply recommendation or endorsement by the U.S. Department of Agriculture. 相似文献
3.
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
4.
There exist large amounts of detergent fiber analysis data [neutral detergent fiber (NDF), acid detergent fiber (ADF), acid
detergent lignin (ADL)] for many different potential cellulosic ethanol feedstocks, since these techniques are widely used
for the analysis of forages. Researchers working in the area of cellulosic ethanol are interested in the structural carbohydrates
in a feedstock (principally glucan and xylan), which are typically determined by acid hydrolysis of the structural fraction
after multiple extractions of the biomass. These so-called dietary fiber analysis methods are significantly more involved
than detergent fiber analysis methods. The purpose of this study was to determine whether it is feasible to correlate detergent
fiber analysis values to glucan and xylan content determined by dietary fiber analysis methods for corn stover. In the detergent
fiber analysis literature cellulose is often estimated as the difference between ADF and ADL, while hemicellulose is often
estimated as the difference between NDF and ADF. Examination of a corn stover dataset containing both detergent fiber analysis
data and dietary fiber analysis data predicted using near infrared spectroscopy shows that correlations between structural
glucan measured using dietary fiber techniques and cellulose estimated using detergent techniques, and between structural
xylan measured using dietary fiber techniques and hemicellulose estimated using detergent techniques are high, but are driven
largely by the underlying correlation between total extractives measured by fiber analysis and NDF/ADF. That is, detergent
analysis data is correlated to dietary fiber analysis data for structural carbohydrates, but only indirectly; the main correlation
is between detergent analysis data and solvent extraction data produced during the dietary fiber analysis procedure. 相似文献
5.
Hanchar RJ Teymouri F Nielson CD McCalla D Stowers MD 《Applied biochemistry and biotechnology》2007,137(1-12):313-325
A process was developed to fractionate corn fiber into glucose- and pentose-rich fractions. Corn fiber was ammonia fiber explosion treated at 90 degrees C, using 1 g anhydrous ammonia pergram of drybiomass, 60% moisture, and 30-min residence time. Twenty four hour hydrolysis of ammonia fiber explosion-treated corn fiber with cellulase converted 83% of available glucanto-glucose. In this hydrolysis the hemicellulose was partially broken down with 81% of the xylan and 68% of the arabinan being contained in the hydrolysate after filtration to remove lignin and other insoluble material. Addition of ethanol was used to precipitate and recover the solubilized hemicellulose from the hydrolysate, followed by hydrolysis with 2% (v/v) sulfuric acid to convert the recovered xylan and arabinan to monomeric sugars. Using this method, 57% of xylose and 54% of arabinose available in corn fiber were recovered in a pentose-rich stream. The carbohydrate composition of the pentose-enriched stream was 5% glucose, 57% xylose, 27% arabinose, and 11% galactose. The carbohydrate composition of the glucose-enriched stream was 87% glucose, 5% xylose, 6% arabinose, and 1% galactose, and contained 83% of glucose available from the corn fiber. 相似文献
6.
Saha Badal C. Dien Bruce S. Bothast Rodney J. 《Applied biochemistry and biotechnology》1998,(1):115-125
Corn fiber, which consists of about 20% starch, 14% cellulose, and 35% hemicellulose, has the potential to serve as a low
cost feedstock for production of fuel ethanol. Currently, the use of corn fiber to produce fuel ethanol faces significant
technical and economic challenges. Its success depends largely on the development of environmentally friendly pretreatment
procedures, highly effective enzyme systems for conversion of pretreated corn fiber to fermentable sugars, and efficient microorganisms
to convert multiple sugars to ethanol. Several promising pretreatment and enzymatic processes for conversion of corn fiber
cellulose, hemicellulose, and remaining starch to fermentable sugars were evaluated. These hydrolyzates were then examined
for ethanol production in bioreactors, using genetically modified bacteria and yeast. Several novel enzymes were also developed
for use in pretreated corn fiber saccharification.
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
7.
Cao Ningjun Xia Youkun Gong Cheng S. Tsao George T. 《Applied biochemistry and biotechnology》1997,(1):129-139
A simple and effective method of treatment of lignocellulosic material was used for the preparation of corn cob for the production
of 2,3-butanediol byKlebsiella oxytoca ATCC 8724 in a simultaneous saccharification and fermentation process. During the treatment, lignin, and alkaline extractives
were solubilized and separated from cellulose and hemicellulose fractions by dilute ammonia (10%) steeping. Hemicellulose
was then hydrolyzed by dilute hydrochloric acid (1%, wJv) hydrolysis at 100°C at atmospheric pressure and separated from cellulose
fraction. The remaining solid, with 90% of cellulose, was then used as the substrate. A butanediol concentration of 25 g/L
and an ethanol concentration of 7 g/L were produced byK. oxytoca from 80 g/L of corn cob cellulose with a cellulase dosage of 8.5 IFPU/g corn cob cellulose after 72 h of SSF. With only dilute
acid hydrolysis, a butanediol production rate of 0.21 g/L/h was obtained that is much lower than the case in which corn cob
was treated with ammonia steeping prior to acid hydrolysis. The butanediol production rate for the latter was 0.36 g/L/h. 相似文献
8.
Wei Liao Zhiyou Wen Sharon Hurley Yan Liu Chuanbin Liu Shulin Chen 《Applied biochemistry and biotechnology》2005,124(1-3):1017-1030
This study focused on the effect of hemicellulose and lignin on enzymatic hydrolysis of dairy manure and hydrolysis process
optimization to improve sugar yield. It was found that hemicellulose and lignin in dairy manure, similar to their role in
other lignocellulosic material, were major resistive factors to enzymatic hydrolysis and that the removal of either of them,
or for best performance, both of them, improved the enzymatic hydrolysis of manure cellulose. This result combined with scanning
electron microscope (SEM) pictures further proved that the accessibility of cellulose to cellulase was the most important
feature to the hydrolysis. Quantitatively, fed-batch enzymatic hydrolysis of fiber without lignin and hemicellulose had a
high glucose yield of 52% with respect to the glucose concentration of 17 g/L at a total enzyme loading of 1300 FPU/L and
reaction time of 160 h, which was better than corresponding batch enzymatic hydrolysis. 相似文献
9.
Cesare Freda Francesco Zimbardi Francesco Nanna Egidio Viola 《Applied biochemistry and biotechnology》2012,167(8):2283-2294
Corn stover was treated by steam explosion process at four different temperatures. A fraction of the four exploded matters was extracted by water. The eight samples (four from steam explosion and four from water extraction of exploded matters) were analysed by wet chemical way to quantify the amount of cellulose, hemicellulose and lignin. Thermogravimetric analysis in air atmosphere was executed on the eight samples. A mathematical tool was developed, using TGA data, to determine the composition of corn stover in terms of cellulose, hemicellulose and lignin. It uses the biomass degradation temperature as multiple linear function of the cellulose, hemicellulose and lignin content of the biomass with interactive terms. The mathematical tool predicted cellulose, hemicellulose and lignin contents with average absolute errors of 1.69, 5.59 and 0.74?%, respectively, compared to the wet chemical method. 相似文献
10.
M. Moniruzzaman B. E. Dale R. B. Hespell R. J. Bothast 《Applied biochemistry and biotechnology》1997,67(1-2):113-126
Corn fiber is a grain-processing residue containing significant amounts of cellulose, hemicellulose, and starch, which is collected in facilities where fuel ethanol is currently manufactured. Preliminary research has shown that corn fiber (30% moisture dry weight basis [dwb]) responds well to ammonia-fiber explosion (AFEX) pretreatment. However, an important AFEX pretreatment variable that has not been adequately explored for corn fiber is sample moisture. In the present investigation, we determined the best AFEX operating conditions for pretreatment of corn fiber at high moisture content (150% moisture dwb). The optimized AFEX treatment conditions are defined in terms of the moisture content, particle size, ammonia to biomass ratio, temperature, and residence time using the response of the pretreated biomass to enzymatic hydrolysis as an indicator. Approximate optimal-pretreatment conditions for unground corn fiber containing 150% (dwb) moisture were found to be: temperature, 90?C; ammonia: dry corn fiber mass ratio, 1:1; and residence time 30 min (average reactor pressure under these conditions was 200 pounds per square inch [psig]). Enzymatic hydrolysis of the treated corn fiber was performed with three different enzyme combinations. More than 80% of the theoretical sugar yield was obtained during enzymatic hydrolysis using the best enzyme combination after pretreatment of corn fiber under the optimized conditions previously described. A simple process for enzyme recovery and reuse to hydrolyze multiple portions of AFEX-treated corn fiber by one portion of enzyme preparation is demonstrated. Using this process, five batches of fresh substrate (at a concentration of 5% w/v) were successfully hydrolyzed by repeated recovery and reuse of one portion of enzyme preparation, with the addition of a small portion of fresh enzyme in each subsequent recycling step. 相似文献
11.
秸秆纤维素的一步快速提取和水解 总被引:4,自引:0,他引:4
研究了秸秆纤维素的一步快速提取方法, 在醋酸和硝酸溶液体系中, 选择10种不同的反应条件, 进行了提取条件优选, 然后对提取的纤维素样品分别进行了水解. 结果发现, 纤维素提取的最佳条件为120 ℃, 固液比为1∶25, 在体积分数为80%的醋酸和10%的硝酸混合溶液中反应20 min, 纤维素的产率为38%. 纤维素样品的水解实验发现, 在最佳条件下提取样品的葡萄糖含量都大于90%, 水解率达到94%. 13C NMR和FTIR分析结果表明, 纤维素的分子结构未被破坏, 但纤维素Ⅰβ含量较高, 木质素和半纤维素的去除率都很高, 表明此方法是比较理想的制备高纯度纤维素的方法. 相似文献
12.
Enhancing the Enzymatic Hydrolysis of Corn Stover by an Integrated Wet-milling and Alkali Pretreatment 总被引:1,自引:0,他引:1
Xun He Yelian Miao Xuejian Jiang Zidong Xu Pingkai Ouyang 《Applied biochemistry and biotechnology》2010,160(8):2449-2457
An integrated wet-milling and alkali pretreatment was applied to corn stover prior to enzymatic hydrolysis. The effects of
NaOH concentration in the pretreatment on crystalline structure, chemical composition, and reducing-sugar yield of corn stover
were investigated, and the mechanism of increasing reducing-sugar yield by the pretreatment was discussed. The experimental
results showed that the crystalline structure of corn stover was disrupted, and lignin was removed, while cellulose and hemicellulose
were retained in corn stover by the pretreatment with 1% NaOH in 1 h. The reducing-sugar yield from the pretreated corn stovers
increased from 20.2% to 46.7% when the NaOH concentration increased from 0% to 1%. The 1% NaOH pretreated corn stover had
a holocellulose conversion of 55.1%. The increase in reducing-sugar yield was related to the crystalline structure disruption
and delignification of corn stover. It was clarified that the pretreatment significantly enhanced the conversion of cellulose
and hemicellulose in the corn stover to sugars. 相似文献
13.
Songlan Sun Gaia De Angelis Dr. Stefania Bertella Marie J. Jones Dr. Graham R. Dick Prof. Esther Amstad Prof. Jeremy S. Luterbacher 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2024,136(5):e202312823
Concerns over the sustainability and end-of-life properties of fossil-derived surfactants have driven interest in bio-based alternatives. Lignocellulosic biomass with its polar functional groups is an obvious feedstock for surfactant production but its use is limited by process complexity and low yield. Here, we present a simple two-step approach to prepare bio-based amphiphiles directly from hemicellulose and lignin at high yields (29 % w/w based on the total raw biomass and >80 % w/w of these two fractions). Acetal functionalization of xylan and lignin with fatty aldehydes during fractionation introduced hydrophobic segments and subsequent defunctionalization by hydrogenolysis of the xylose derivatives or acidic hydrolysis of the lignin derivatives produced amphiphiles. The resulting biodegradable xylose acetals and/or ethers, and lignin-based amphiphilic polymers both largely retained their original natural structures, but exhibited competitive or superior surface activity in water/oil systems compared to common bio-based surfactants. 相似文献
14.
Xinping Li Xiaolin Luo Kecheng Li J. Y. Zhu J. Dennis Fougere Kimberley Clarke 《Applied biochemistry and biotechnology》2012,168(6):1556-1567
The effects of pretreatment by dilute acid and sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) on substrate morphology, cell wall physical and chemical structures, along with the subsequent enzymatic hydrolysis of lodgepole pine substrate were investigated. FE-SEM and TEM images of substrate structural morphological changes showed that SPORL pretreatment resulted in fiber separation, where SPORL high pH (4.2) pretreatment exhibited better fiber separation than SPORL low pH (1.9) pretreatment. Dilute acid pretreatment produced very poor fiber separation, consisting mostly of fiber bundles. The removal of almost all hemicelluloses in the dilute acid pretreated substrate did not overcome recalcitrance to achieve a high cellulose conversion when lignin removal was limited. SPORL high pH pretreatment removed more lignin but less hemicellulose, while SPORL low pH pretreatment removed about the same amount of lignin and hemicelluloses in lodgepole pine substrates when compared with dilute acid pretreatment. Substrates pretreated with either SPORL process had a much higher cellulose conversion than those produced with dilute acid pretreatment. Lignin removal in addition to removal of hemicellulose in SPORL pretreatment plays an important role in improving the cellulose hydrolysis of the substrate. 相似文献
15.
Xuejun Pan Dan Xie Neil Gilkes David J. Gregg Jack N. Saddler 《Applied biochemistry and biotechnology》2005,124(1-3):1069-1079
Pretreatment of Douglas-fir by steam explosion produces a substrate containing approx 43% lignin. Two strategies were investigated
for reducing the effect of this residual lignin on enzymatic hydrolysis of cellulose: mild alkali extraction and protein addition.
Extraction with cold 1% NaOH reduced the lignin content by only approx 7%, but cellulose to glucose conversion was enhanced
by about 30%. Before alkali extraction, addition of exogenous protein resulted in a significant improvement in cellulose hydrolysis,
but this protein effect was substantially diminished after alkali treatment. Lignin appears to reduce cellulose hydrolysis
by two distinct mechanisms: by forming a physical barrier that prevents enzyme access and by non-productively binding cellulolytic
enzymes. Cold alkali appears to selectively remove a fraction of lignin from steam-exploded Douglas-fir with high affinity
for protein. Corresponding data for mixed softwood pretreated by organosolv extraction indicates that the relative importance
of the two mechanisms by which residual lignin affects hydrolysis is different according to the pre- and post-treatment method
used. 相似文献
16.
Renata Bura Rodney J. Bothast Shawn D. Mansfield John N. Saddler 《Applied biochemistry and biotechnology》2003,106(1-3):319-335
A batch reactor was employed to steam explode corn fiber at various degrees of severity to evaluate the potential of using
this feedstock as part of an enzymatically mediated cellulose-to-ethanol process. Severity was controlled by altering temperature
(150–230°C), residence time (1–9 min), and SO2 concentration (0–6% [w/w] dry matter). The effects of varying the different parameters were assessed by response surface
modeling. The results indicated that maximum sugar yields (hemicellulose-derived water soluble, and cellulose-derived following
enzymatic hydrolysis) were recovered from corn fiber pretreated at 190°C for 5 minutes after exposure to 3% SO2. Sequential SO2-catalyzed steam explosion and enzymatic hydrolysis resulted in a conversion efficiency of 81% of the combined original hemicellulose
and cellulose in the corn fiber to monomeric sugars. An additional posthydrolysis step performed on water soluble hemicellulose
stream increased the concentration of sugars available for fermentation by 10%, resulting in the high conversion efficiency
of 91%. Saccharomyces cerevisiae was able to ferment the resultant corn fiber hydrolysates, perhydrolysate, and liquid fraction from the posthydrolysis steps
to 89, 94, and 85% of theoretical ethanol conversion, respectively. It was apparent that all of the parameters investigated
during the steam explosion pretreatment had a significant effect on sugar recovery, inhibitory formation, enzymatic conversion
efficiency, and fermentation capacity of the yeast. 相似文献
17.
Palonen H Thomsen AB Tenkanen M Schmidt AS Viikari L 《Applied biochemistry and biotechnology》2004,117(1):1-17
The wet oxidation pretreatment (water, oxygen, elevated temperature, and pressure) of softwood (Picea abies) was investigated for enhancing enzymatic hydrolysis. The pretreatment was preliminarily optimized. Six different combinations
of reaction time, temperature, and pH were applied, and the compositions of solid and liquid fractions were analyzed. The
solid fraction after wet oxidation contained 58–64% cellulose, 2–16% hemicellulose, and 24–30% lignin. The pretreatment series
gave information about the roles of lignin and hemicellulose in the enzymatic hydrolysis. The temperature of the pretreatment,
the residual hemicellulose content of the substrate, and the type of the commercial cellulase preparation used were the most
important factors affecting the enzymatic hydrolysis. The highest sugar yield in a 72-h hydrolysis, 79% of theoretical, was
obtained using a pretreatment of 200°C for 10 min at neutral pH. 相似文献
18.
Cellulose degradation of 20% urea treated and 20% urea–10 kGy gamma treated Thai rice straw and corn stalk showed that combination effect of urea and gamma radiation gave a higher % decrease in neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL), cellulose, hemicellulose, and lignin and cutin in comparison with urea effect only for both room temperature storage and room temperature +258 K storage. The results also indicated that cellulose degradation proceeded with time, even at 258 K. A drastic drop to less than half of the original contents in NDF, ADF, and ADL could not be obtained in this study. 相似文献
19.
Nghiem NP Montanti J Johnston DB Drapcho C 《Applied biochemistry and biotechnology》2011,164(8):1390-1404
A process was developed to fractionate and isolate the hemicellulose B component of corn fiber generated by corn wet milling.
The process consisted of pretreatment by soaking in aqueous ammonia followed by enzymatic cellulose hydrolysis, during which
the hemicellulose B was solubilized by cleavage into xylo-oligosaccharides and subsequently recovered by precipitation with
ethanol. The pretreatment step resulted in high retention of major sugars and improvement of subsequent enzymatic hydrolysis.
The recovered hemicellulose B was hydrolyzed by a cocktail of enzymes that consisted of β-glucosidase, pectinase, xylanase,
and ferulic acid esterase (FAE). Xylanase alone was ineffective, demonstrating yields of less than 2% of xylose and arabinose.
The greatest xylose and arabinose yields, 44% and 53%, respectively, were obtained by the combination of pectinase and FAE.
A mass balance accounted for 87% of the initially present glucan, 91% of the xylan, and 90% of the arabinan. The developed
process offered a means for production of corn fiber gum as a value-added co-product and C5 sugars, which could be converted
to other valuable co-products through fermentation in a corn wet-milling biorefinery. 相似文献
20.
Abolghasem Shahbazi Yebo Li Michele R. Mims 《Applied biochemistry and biotechnology》2005,124(1-3):973-987
The FIRST (Feedstock Impregnation and Rapid Steam Treatment) approach was used in this study to isolate extractives, hemicellulose,
lignin, fibers, and cellulosic fines of softwood. With hydrolysis and fermentation of the hemicellulose and cellulosic fines
fractions, this approach produces four co-products: extractives, cellulose, lignin, and ethanol. The first unit operation
uses aqueous/alcohol to remove and recover the extractive rich fraction. The second unit operation uses steam treatment to
destructure the matrix and solubilize a large fraction of the hemicelluloses. The third unit operation uses alkaline delignification
to dissolve a lignin fraction. The fourth unit operation uses the refining process to separate fibers from cellulosic fines.
The fibers are bleached. The yields of lignin and bleached cellulose were about 20.0 kg and 38.3 kg out of 100 kg initial
dry pine, respectively. The recovered hemicelluloses were 23.3 kg (containing 16.1 kg hexoses and 5.0 kg pentoses) and the
cellulose fines derived hexoses amounted to 3.4 kg out of 100 kg initial dry pine. When the two liquors containing the hemicellulose
sugars and the cellulose fines-derived hexoses were fermented for ethanol production, an ethanol yield of 6.8 kg was obtained. 相似文献