Effects of a Steam Explosion Pretreatment on Sugar Production by Enzymatic Hydrolysis and Structural Properties of Reed Straw

Abstract Background The bioconversion of lignocellulose to fermentable C5/C6-saccharides is composed of pretreatment and enzymatic hydrolysis. Lignin, as one of the main components, resists lignocellulose to be bio-digested. Alkali and organosolv treatments were reported to be able to delignify feedstocks and loose lignocellulose structure. In addition, the use of additives was an alternative way to block lignin and reduce the binding of cellulases to lignin during hydrolysis. However, the relatively high cost of these additives limits their commercial application. Results This study explored the feasibility of using elephant grass (Pennisetum purpureum) and reed straw (Phragmites australis), both of which are important fibrous plants with high biomass, no-occupation of cultivated land, and soil phytoremediation, as feedstocks for bio-saccharification. Compared with typical agricultural residues, elephant grass and reed straw contained high contents of cellulose and hemicellulose. However, lignin droplets on the surface of elephant grass and the high lignin content in reed straw limited their hydrolysis performances. High hydrolysis yield was obtained for reed straw after organosolv and alkali pretreatments via increasing cellulose content and removing lignin. However, the hydrolysis of elephant grass was only enhanced by organosolv pretreatment. Further study showed that the addition of bovine serum albumin (BSA) or thioredoxin with His- and S-Tags (Trx-His-S) improved the hydrolysis of alkali-pretreated elephant grass. In particular, Trx-His-S was first used as an additive in lignocellulose saccharification. Its structural and catalytic properties were supposed to be beneficial for enzymatic hydrolysis. Conclusions Elephant grass and reed straw could be used as feedstocks for bioconversion. Organosolv and alkali pretreatments improved their enzymatic sugar production; however, the increase in hydrolysis yield of pretreated elephant grass was not as effective as that of reed straw. During the hydrolysis of alkali-pretreated elephant grass, Trx-His-S performed well as additive, and its structural and catalytic capability was beneficial for enzymatic hydrolysis.

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Valorisation of olive stone by-product for sugar production using a sequential acid/steam explosion pretreatment

Industrial Crops and Products ◽

10.1016/j.indcrop.2020.112279 ◽

2020 ◽

Vol 148 ◽

pp. 112279 ◽

Cited By ~ 4

Author(s):

C. Padilla-Rascón ◽

E. Ruiz ◽

I. Romero ◽

E. Castro ◽

J.M. Oliva ◽

...

Keyword(s):

Steam Explosion ◽

Sugar Production ◽

Steam Explosion Pretreatment ◽

Olive Stone

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Effect of Inhibitors Released During Steam-Explosion Pretreatment of Barley Straw on Enzymatic Hydrolysis

Applied Biochemistry and Biotechnology ◽

10.1385/abab:129:1:278 ◽

2006 ◽

Vol 129 (1-3) ◽

pp. 278-288 ◽

Cited By ~ 106

Author(s):

MA Prado GArcía-Aparicio ◽

Ignacio Ballesteros ◽

Alberto González ◽

JoséMiguel Oliva ◽

Mercedes Ballesteros ◽

...

Keyword(s):

Enzymatic Hydrolysis ◽

Steam Explosion ◽

Barley Straw ◽

Steam Explosion Pretreatment ◽

Effect Of Inhibitors

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Industrial-scale steam explosion pretreatment of sugarcane straw for enzymatic hydrolysis of cellulose for production of second generation ethanol and value-added products

Bioresource Technology ◽

10.1016/j.biortech.2012.12.030 ◽

2013 ◽

Vol 130 ◽

pp. 168-173 ◽

Cited By ~ 103

Author(s):

Fernando M.V. Oliveira ◽

Irapuan O. Pinheiro ◽

Ana M. Souto-Maior ◽

Carlos Martin ◽

Adilson R. Gonçalves ◽

...

Keyword(s):

Enzymatic Hydrolysis ◽

Steam Explosion ◽

Value Added ◽

Enzymatic Hydrolysis Of Cellulose ◽

Sugarcane Straw ◽

Steam Explosion Pretreatment ◽

Hydrolysis Of Cellulose ◽

Hydrolysis Of ◽

Second Generation Ethanol ◽

Value Added Products

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Saccharification Yield through Enzymatic Hydrolysis of the Steam-Exploded Pinewood

Energies ◽

10.3390/en13174552 ◽

2020 ◽

Vol 13 (17) ◽

pp. 4552 ◽

Cited By ~ 1

Author(s):

Merve Nazli Borand ◽

Asli Isler Kaya ◽

Filiz Karaosmanoglu

Keyword(s):

Enzymatic Hydrolysis ◽

Steam Explosion ◽

Liquid Fraction ◽

Sugar Content ◽

Release Time ◽

Variable Parameters ◽

Glucose Yield ◽

Steam Explosion Pretreatment ◽

Saccharification Yield ◽

Hydrolysis Of

Pressure, temperature, and retention time are the most studied parameters in steam explosion pretreatment. However, this work aimed to fix these parameters and to evaluate the influences of several less investigated steam explosion parameters on the saccharification yield in hydrolysis. In this study, firstly, pinewood samples smaller than 200 µm were treated with steam explosion at 190 °C for 10 min. The variable parameters were biomass loading, N2 pressure, and release time. Steam-exploded samples were hydrolyzed with the Trichoderma reesei enzyme for saccharification for 72 h. The sugar content of the resultant products was analyzed to estimate the yield of sugars (such as glucose, xylose, galactose, mannose, and arabinose). The best glucose yield in the pulp was achieved with 4 g of sample, N2 pressure of 0.44 MPa, and short release time (22 s). These conditions gave a glucose yield of 97.72% in the pulp, and the xylose, mannose, galactose, and arabinose yields in the liquid fraction were found to be 85.59%, 87.76%, 86.43%, and 90.3%, respectively.

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