Enzymatic production of xylooligosaccharides from cotton stalks

Date

2007-07-11

Author

Akpinar, Ozlem
Ak, Ozlem
Kavas, Aysegul
Bakir, Ufuk
Yılmaz, Levent

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

177
views

0
downloads

Xylooligosaccharide (XO) production was performed from xylan, which was obtained by alkali extraction from cotton stalk, a major agricultural waste in Turkey. Enzymatic hydrolysis was selected to prevent byproduct formation such as xylose and furfural. Xylan was hydrolyzed using a commercial xylanase preparation, and the effects of pH, temperature, hydrolysis period, and substrate and enzyme concentrations on the XO yield and degree of polymerization (DP) were investigated. Cotton stalk contains about 21% xylan, the composition of which was determined as 84% xylose, 7% glucose, and 9% uronic acid after complete acid hydrolysis. XOs in the DP range of 2-7 (X6 approximate to X5 > X2 > X3) were obtained with minor quantities of xylose in all of the hydrolysis conditions used. Although after 24 h of hydrolysis at 40 degrees C, the yield was about 53%, the XO production rate leveled off after 8-24 h of hydrolysis. XO yield was affected by all of the parameters investigated; however, none of them affected the DP of the end product significantly, except the hydrolysis period. Enzyme hydrolysis was maintained by the addition of fresh substrate after 72 h of hydrolysis, indicating the persistence of enzyme activity. The optimal hydrolysis conditions were determined as 40 degrees C, pH 5.4, and 2% xylan. The obtained product was fractionated via ultrafiltration by using 10, 3, and 1 kDa membranes. Complete removal of xylanase and unhydrolyzed xylan was achieved without losing any oligosaccharides having DP 5 or smaller by 10 kDa membrane. After a two-step membrane processing, a permeate containing mostly oligosaccharides was obtained.

Subject Keywords

Xylooligosaccharides, Cotton stalk, Xylan, Enzymatic hydrolysis, Agricultural waste

URI

https://hdl.handle.net/11511/39635

Journal

JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY

DOI

https://doi.org/10.1021/jf063580d

Collections

Department of Chemical Engineering, Article

Suggestions

OpenMETU
Core

Comparison of acid and enzymatic hydrolysis of tobacco stalk xylan for preparation of xylooligosaccharides AKPINAR, ÖZLEM; Erdogan, Kader; Bakir, Ufuk; Yılmaz, Levent (2010-01-01) Tobacco stalk (TS), a major agricultural waste in the Black Sea region of Turkey, was used for the production of xylooligosaccharides (XOs). It contains about 22 g/100 g xylan whose composition was determined as 93.5 g/100 g xylose, 6.54 g/100 g glucose and 11.2 g/100 g uronic acid after complete acid hydrolysis. XO production was performed by enzymatic and acid hydrolysis of xylan which was obtained by alkali extraction from tobacco stalk. In enzyme hydrolysis, xylan was hydrolyzed using a xylanase prepara...
Biogas production potential from cotton wastes Isci, A.; Demirer, Göksel Niyazi (2007-04-01) The anaerobic treatability and methane generation potential of three different cotton wastes namely, cotton stalks, cotton seed hull and cotton oil cake were determined in batch reactors. In addition, the effects of nutrient and trace metal supplementation were also investigated. To this purpose biochemical methane potential (BMP) experiments were performed for two different waste concentrations, namely 30 and 60g/l. The results revealed that cotton wastes can be treated anacrobically and are a good source ...
Experimental Investigation of the Original Project of Yukari Kalekoy Dam and Hydroelectric Power Plant Spillway Göğüş, Mustafa; Altan Sakarya, Ayşe Burcu; Köken, Mete (Elsevier BV; 2016-06-17) Hydraulic model tests of the spillway of Yukar Kalekoy Dam and Hydroelectric Power Plant (HPP) were carried out at Hydromechanics Laboratory of Middle East Technical University (METU), Ankara. In order to investigate the flow conditions in the approach channel, over the weir structure, around the spillway piers, along the spillway chute channels and after the flip buckets, and also to observe the performance of the aeration devices, a model of 1/70 length scale was constructed. The model area covers an abou...
Cadmium removal using clinoptilolite : influence of conditioning and regeneration Gedik, Kadir; İmamoğlu, İpek; Department of Environmental Engineering (2006) Clinoptilolite samples obtained from two deposits in Turkey were tested for their potential in removing cadmium from aqueous solutions. Preliminary experiments in batch mode revealed inferior cadmium uptake at low pH. Particle size was found to have no effect on cadmium removal efficiency suggesting the use of exchangeable cations found in the internal/available sites. Increasing temperature yielded positive, whereas prewashing had no effect on cadmium removal using both clinoptilolite samples. The Langmuir...
Thermal analysis and kinetics of biomass samples Kök, Mustafa Verşan (2013-02-01) In this research, combustion behavior of agricultural residues known as miscanthus, poplar wood, and rice husk was investigated using thermal analysis techniques. Differential scanning calorimeter (DSC) and thermogravimetry (TG-DTG) techniques were used. Combustion experiments were performed at five different heating rates (5, 10, 15, 25, and 50 degrees C/min). The reaction regions, ignition and burnout temperatures, heat flow rate values of biomass samples are determined. Activation energy of the biomass s...

Citation Formats

O. Akpinar, O. Ak, A. Kavas, U. Bakir, and L. Yılmaz, “Enzymatic production of xylooligosaccharides from cotton stalks,” JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY, pp. 5544–5551, 2007, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/39635.