scholarly journals Two-Step Delignification of Miscanthus To Enhance Enzymatic Hydrolysis: Aqueous Ammonia Followed by Sodium Hydroxide and Oxidants

2014 ◽  
Vol 28 (1) ◽  
pp. 542-548 ◽  
Author(s):  
Zhongguo Liu ◽  
Sasisanker Padmanabhan ◽  
Kun Cheng ◽  
Hongxue Xie ◽  
Amit Gokhale ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Sodium Hydroxide ◽  
Aqueous Ammonia

Improving the efficiency of enzymatic hydrolysis of Eucalyptus residues with a modified aqueous ammonia soaking method

2018 ◽  
Vol 33 (2) ◽  
pp. 165-174 ◽  
Author(s):  
Dan Huo ◽  
Qiulin Yang ◽  
Guigan Fang ◽  
Qiujuan Liu ◽  
Chuanling Si ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Enzymatic Hydrolysis ◽  
Aqueous Ammonia ◽  
Pulp Mill ◽  
Fiber Surface ◽  
Raw Material ◽  
Sem Images ◽  
Aqueous Ammonia Soaking ◽  
Guaiacyl Lignin ◽  
Hydrolysis Of

Abstract Eucalyptus residues from pulp mill were pretreated with aqueous ammonia soaking (AAS) method to improve the efficiency of enzymatic hydrolysis. The optimized condition of AAS was obtained by response surface methodology. Meanwhile, hydrogen peroxide was introduced into the AAS system to modify the AAS pretreatment (AASP). The results showed that a fermentable sugar yield of 64.96 % was obtained when the eucalypt fibers were pretreated at the optimal conditions, with 80 % of ammonia (w/w) for 11 h and keeping the temperature at 90 °C. In further research it was found that the addition of H2O2 to the AAS could improve the pretreatment efficiency. The delignification rate and enzymatic digestibility were increased to 64.49 % and 73.85 %, respectively, with 5 % of hydrogen peroxide being used. FTIR analysis indicated that most syringyl and guaiacyl lignin and a trace amount of xylan were degraded and dissolved during the AAS and AASP pretreatments. The CrI of the raw material was increased after AAS and AASP pretreatments, which was attributed to the removal of amorphous portion. SEM images showed that microfibers were separated and explored from the initial fiber structure after AAS pretreatment, and the AASP method could improve the destructiveness of the fiber surface.

Stepwise pretreatment of aqueous ammonia and ethylenediamine improve enzymatic hydrolysis of corn stover

2018 ◽  
Vol 124 ◽  
pp. 201-208 ◽  
Author(s):  
Jia-Qing Zhu ◽  
Wen-Chao Li ◽  
Lei Qin ◽  
Xiong Zhao ◽  
Si Chen ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Corn Stover ◽  
Aqueous Ammonia ◽  
Hydrolysis Of

scholarly journals Optimization of alkali pretreatment of wheat straw to be used as substrate for biofuels production  

2013 ◽  
Vol 59 (No. 12) ◽  
pp. 537-542 ◽  
Author(s):  
K. Jaisamut ◽  
L. Paulová ◽  
P. Patáková ◽  
M. Rychtera ◽  
K. Melzoch
Keyword(s):  
Response Surface Methodology ◽  
Enzymatic Hydrolysis ◽  
Sodium Hydroxide ◽  
Wheat Straw ◽  
Response Surface ◽  
Fermentable Sugars ◽  
Alkali Pretreatment ◽  
The Media ◽  
Pretreatment Conditions ◽  
Expert Designer

Alkali pretreatment of wheat straw was optimized by response surface methodology to maximize yields of fermentable sugars in subsequent enzymatic hydrolysis and to remove maximum lignin in order to improve rheological attributes of the media. The effects of pretreatment conditions on biomass properties were studied using the Expert Designer software. Concentration of sodium hydroxide and temperature were the factors most affecting pretreatment efficiency. At the optimum (80°C, 39 min, 0.18 g NaOH and 0.06 g lime per g of raw biomass), 93.1 ± 1.0% conversion of cellulose to glucose after enzymatic hydrolysis and 80.3 ± 1.2% yield of monosaccharides (glucose plus xylose and arabinose) from cellulose and hemicellulose of wheat straw were achieved.

Urea treatment as a means of preserving/processing moist wheat for intensively finished cattle

1999 ◽  
Vol 1999 ◽  
pp. 54-54 ◽  
Author(s):  
M. Lewis ◽  
B.G. Lowman ◽  
M. Ford
Keyword(s):  
Sodium Hydroxide ◽  
Dry Matter ◽  
Aqueous Ammonia ◽  
Wheat Variety ◽  
Urea Solution ◽  
Processing Methods ◽  
Urea Treatment

Wheat requires processing for feeding to cattle otherwise large amount remain undigested. Processing methods can be mechanical or chemical (sodium hydroxide or aqueous ammonia) but these require specialised equipment and/or the use of contractors. The objective of this trial was to evaluate moist wheat fed whole, but treated with urea at harvest as a means of generating ammonia in situ, in diets for intensively finished cattle.Eighty tonnes of wheat (variety Riband) was harvested on 21-22 August 1997 at a dry matter (DM) of 750 g/kg and treated immediately with 53 l/tonne of a urea solution (430 g urea/litre) to supply 30 g urea/kg wheat DM. Treatment was achieved by applying the urea to the wheat as it was augered into the storage silo, which was then sealed with polythene.

scholarly journals Synthesis of the anhydrides of α-aminoacyl glucosamines

1913 ◽  
Vol 88 (605) ◽  
pp. 455-461 ◽  
Keyword(s):  
Amino Acids ◽  
Sodium Hydroxide ◽  
Aqueous Ammonia ◽  
Degradation Products ◽  
Amino Sugars ◽  
Amino Group ◽  
Glucosamine Hydrochloride ◽  
Aliphatic Acids ◽  
Condensation Products

The behaviour of the albumin glucosides and the mucus bodies known as mucins, mucinogens, mucoids , and hyalogens , on hydrolysis suggests the probability that these complex proteins would bear the same relation to the condensation products of the sugars or the amino-sugars with the amino-acids as the simpler proteins bear to the polypeptides. Consequently, the authors decided two years ago to make a start in the synthesis of the glucoproteins by preparing the condensation products of glucosamine with the amino-aliphatic acids, in order that their properties and behaviour towards ferments could be ascertained and compared with those of the degradation products of the glucoproteins and thereby throw some light on the constitution of these complex and important organic bodies. After many failures, the method of synthesis which we eventually adopted for the condensation of glucosamine with amino-aliphatic acids was somewhat similar to one of the methods employed by Emil Fischer and his co-workers in the synthesis of the polypeptides. In brief, the method consists in condensing α -bromoacyl haloids with glucosamine hydrochloride in the presence of sodium hydroxide, and then displacing the halogen in the resulting α -bromoacyl glucosamines by an amino-group through the action of cold aqueous ammonia, viz:- α -Bromoacyl Haloid + Glucosamine Hydrochloride. sodium ↓ hydroxide. α -Bromoacyl Glucosamine. aqueous ↓ ammonia. Anhydride of α -Aminoacyl Glucosamine.

Pterins. III. Methylation of 6-Methyl-5,6,7,8-tetrahydropterin, N-5-Demethylation of 1,3,5,6-Tetramethyl-5,6,7,8-tetrahydropterinium chloride hydrochloride and exchange of the 5-Methyl group in 5,6-Dimethyl-5,6,7,8-tetrahydropterin

1978 ◽  
Vol 31 (5) ◽  
pp. 1081 ◽  
Author(s):  
WLF Armarego ◽  
H Schou
Keyword(s):  
Sodium Hydroxide ◽  
Aqueous Ammonia ◽  
Methyl Group ◽  
Aerial Oxidation ◽  
Tetrahydrofolic Acid

Methylation of 6-methyl-5,6,7,8-tetrahydropterin (1) in the presence of sodium hydroxide furnishes 1,3,6-trimethyl-5,6,7,8-tetrahydropterinium chloride (3) which can be methylated further to yield 1,3,5,6- tetramethyl-5,6,7,8-tetrahydropterinium chloride (4). Demethylation of the latter salt occurred on a Dowex 50W/3 N-aqueous ammonia column with loss of the 5-methyl group to give the salt (3). The structures of these salts were deduced by a study of similar alkylations of authentic 1,6-dimethyl-,3,6-dimethyl- (6), 5,6-dimethyl-(15), 6,8-dimethyl-, 1,5,6-trimethyl-, and 3,5,6-trimethyl-5,6,7,8-tetrahydropterin (7), and of 6-methyl-2-methylamino-5,6,7,8-tetrahydropteridin- 4(3H)-one (10). Methylation of 5,6-dimethyl-5,6,7,8-tetrahydropterin (15), with trideuteromethyl iodide in the presence of alkali, was shown to give the tetramethylpterinium salt (4) in which considerable exchange of the 5-methyl group by a trideuteromethyl group had taken place. ��� The pterinium salts (3) and (4) were considerably more stable to aerial oxidation than 6-methyl-, 1,6-, 3,6-, 5,6-, 6,7-, 6,8-dimethyl-, and 1,5,6-trimethyl-5,6,7,8-tetrahydropterin. Loss of the 5-methyl group from the salt (4), and exchange of the 5-methyl group in the 5,6- dimethylpterin (15), allowed a mechanism for the enzymic transfer of the 5-methyl group in 5-methyl-5,6,7,8-tetrahydrofolic acid in biological methylations to be proposed.

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