scholarly journals Effect of cellulose structure on enzymatic hydrolysis

BioResources ◽  
2011 ◽  
Vol 6 (3) ◽  
pp. 2818-2835 ◽  
Author(s):  
Michael Ioelovich ◽  
Ely Morag

Enzymatic hydrolysis of non-dried and dried cellulose samples having various particles size, degree of polymerization, porosity, crystalline polymorph, and content of non-crystalline domains has been studied. Regression analysis was carried out to determine contribution of various structural features of cellulose samples to their hydrolysability. It was found that particle size, degree of polymerization, and crystalline polymorph had a negligible influence on the conversion degree of cellulose into glucose under the effect of the cellulolytic enzyme. Such characteristics as the pores volume had a fair impact on the conversion degree of cellulose. Drying of the wet samples caused decreasing of the hydrolysability of cellulose due to irreversible collapse of the pores volume. The content of non-crystalline domains (Ax) in cellulose had the highest effect on the rate of enzymatic hydrolysis and average conversion degree (αa) of cellulose into glucose. A linear dependence αa = f(Ax) was established both for dried and non-dried cellulose samples.

Author(s):  
Qi Zhang ◽  
Pengfei Zhang ◽  
Z. J. Pei ◽  
Linda Pei

Ethanol made from cellulosic biomass is an alternative to petroleum-based liquid transportation fuels. Enzymatic hydrolysis uses enzymes to convert cellulosic biomass into sugars that are fermented into ethanol. In order to increase sugar yield, various treatments (such as biomass size reduction and pretreatment) are applied to cellulosic biomass before enzymatic hydrolysis. These treatments will alter structure parameters of cellulosic biomass, such as crystallinity index, degree of polymerization, particle size, pore volume, and specific surface area. There are currently no review papers on these structure parameters of cellulosic biomass in ethanol manufacturing. This paper reviews experimental investigations in the literature about effects of various treatments on the structure parameters of cellulosic biomass.


2004 ◽  
Vol 58 (7-8) ◽  
pp. 322-326 ◽  
Author(s):  
Miodrag Lazic ◽  
Suzana Raskovic ◽  
Mihajlo Stankovic ◽  
Vlada Veljkovic

The hydrolysis of potato starch using one (Termamyl or Fungamyl) and two combined (Termamyl and Supersan) commercial enzyme preparations and ethanol production from the hydrolysates obtained using the yeast Saccharomyces cerevisiae were studied. Potato tubers were previously prepared as mash or flour. The study dealt with the effects of the hydromodulus (1:1 and 1:0.5), particle size (0.1, 0.2 and 0.4 mm) as well as the type and concentration of enzyme on the enzymatic hydrolysis of potato starch. The highest dextrose equivalent (79.3%, DE) was achieved during two-enzyme hydrolysis (combination of two enzyme preparations: Termamyl 14.4 KNU/dm3 and Supersan 28.8 AGU/dm3) of starch from potato flour (particle size: 0.1-0.2 mm) at an inital starch concentration of 75 g/dm3. During the two-enzyme hydrolysis, a lower DE (61%) was achieved when potato mash was used as a starch source. Using Termamyl (14,4 KNU/dm3) and potato mash a higher DE was achieved at the hydromodulus 1:1 (51.2%) than at the hydromodulus 1:0.5 (40.9%). The highest ethanol concentration (5.0 vol%) was obtained when the hydrolyzate of potato flour from the two-enzyme process was used as a substrate for alcoholic fermentation.


Folia Medica ◽  
2017 ◽  
Vol 59 (2) ◽  
pp. 210-216 ◽  
Author(s):  
Paolina K. Lukova ◽  
Diana P. Karcheva-Bahchevanska ◽  
Veselin P. Bivolarski ◽  
Rumen D. Mladenov ◽  
Ilia N. Iliev ◽  
...  

AbstractBackground:Plantago majorL. leaves have been used for centuries by the traditional medicine in the treatment of infectious disorders of the respiratory, urinary and digestive tracts. Researchers have reported that hot water extracts ofPlantago majorpossess a broad-spectrum of anticancer, antioxidant and antiviral activities, as well as activities which modulate cell-mediated immunity. Their beneficial properties may be due to the significant content of polysaccharides. The polysaccharides that have been isolated from the leaves ofPlantago majorL. have different structures – pectic substances, galactans, arabinogalactans, glucomannans.Aim:The aim of this paper was to study the correlation between the structure of the water extractable polysaccharides isolated fromPlantago majorL. leaves and their enzymatic hydrolysis with different carbohydrate hydrolases.Materials and methods:The hydrolysis reactions were performed with the enzymes hemicellulase and mannanase. Spectrophotometric total reducing sugars assay was used to examine the hydrolysis yield. The monosaccharide and oligosaccharide compositions were determined using HPLC analysis.Results:The highest hydrolysis yield of the water extractable polysaccharides fromPlantago majorleaves was obtained by treatment with hemicellulase. The hydrolysis yield increased with the augmentation of the ratio of enzyme to polysaccharide. Galactose was the prevalent monosaccharide identified in the composition of the isolated polysaccharides. Oligosaccharides with different degree of polymerization were also detected.Conclusion:The enzymatic hydrolysis of water extractable polysaccharides fromPlantago majorleaves allows us to obtain different types of oligosaccharides with beneficial effects on both human health and industry.


2012 ◽  
Vol 48 (3) ◽  
pp. 312-317 ◽  
Author(s):  
V. V. Shutova ◽  
A. I. Yusipovich ◽  
E. Yu. Parshina ◽  
D. O. Zakharkin ◽  
V. V. Revin

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