scholarly journals Conversion of Lignocellulosic Material Into Fermentable Sugars

2017 ◽  
Vol 12 (4) ◽  
pp. 141-153
Author(s):  
Asem Hassan Mohammed ◽  
Frank Behrendt Behrendt ◽  
Frank Jürgen Methner

Enzymatic hydrolysis process of lignocellulosic biomass materials is difficult because of inherent structural features of biomass, which represents barriers that prevent complete hydrolysis; therefore, pretreatment techniques are necessary to render biomass highly digestible in enzymatic hydrolysis process. In this research, (non?) oxidative short-term lime pretreatment of willow wood was used. A weight of  11.40 g of willow wood was mixed with an excess of calcium hydroxide (0.4 g Ca(OH)2/g raw biomass) and water loading (15 g/g raw biomass). Lime pretreatment was carried out for various periods of time including 1, 2, 3.5, 5 and 6 h, with temperatures at 100, 113, 130, 147 and 1600C, and oxygen pressures as oxidativeagent (6, 9, 13.5, 17.8, 21 bar absolute). The optimization of both pretreatment and enzymatic hydrolysis were depended on the maximum overall yields of glucan and xylan after two processes of lime pretreatment and enzymatic hydrolysis. The optimal conditions of pretreatment were as follow: 1) 1.33 h, 1470C, 17.8 bar absolute, 0.26 g Ca(OH)2/g raw biomass. 2) 1.25 h, 155 0C, 21 bar absolute, 0.26 Ca(OH)2/g raw biomass. Furthermore, the optimal values for low impact factors such as water loading was 15 g/g raw biomass and particle size was less than 3 mm. The optimal conditions of enzymatic hydrolysis were as follow: Cellulase enzymeloading was 0.1 g /g glucan in raw biomass, at substrate concentration of 50 g/L during 72 h of enzymatic hydrolysis The yield of enzymatic hydrolysis under these conditions were as follow: 96.00 g glucan/100 g of glucan in raw biomass, and 65.00 g xylan/100 g xylan in raw biomass.

2021 ◽  
Vol 17 (1) ◽  
pp. 23
Author(s):  
Anggela Anggela ◽  
Widiastuti Setyaningsih ◽  
Santad Wichienchot ◽  
Eni Harmayani

Porang (Amorphophallus oncophyllus) is an indigenous tuber of Indonesia that rich in glucomannan. An alternative approach to produce porang oligo-glucomannan (POG) as prebiotic from porang glucomannan (PGM) was made by enzymatic hydrolysis using β-mannanase. This study aimed to  produce POG under optimal conditions by controlled enzymatic hydrolysis process. The PGM flour contained 96.12% of indigestible carbohydrates. The optimum condition of enzymatic hydrolysis producing the highest reducing sugar was as follows: temperature 37°C, pH 5.5, a ratio of enzyme to the substrate (E/S) 1:1000, and reaction time 4 h. HPLC analysis confirmed that 99.45% of the resulting POG consisted of oligosaccharides with a degree of polymerization (DP) 3. Hence, the PGM utilized in this study has been proven as a potential substrate for POG production. Additionally, the resulting POG was considered as a functional ingredient due to has prebiotic potential.


2017 ◽  
Vol 1 (2) ◽  
pp. 208-214 ◽  
Author(s):  
M. Falls ◽  
D. Meysing ◽  
S. Lonkar ◽  
C. Liang ◽  
M. N. Karim ◽  
...  

Abstract To feed a growing population, alternative sources of animal feed (e.g., lignocellulose) are needed to replace grains (e.g., corn). Oxidative lime pretreatment (OLP) increases lignocellulose digestibility by removing lignin and hemicellulose acetyl content. Adding a mechanical pretreatment (e.g., ball milling) further improves digestibility. This study determines the effectiveness of OLP and ball milling to enhance the ruminant digestibility of lignocellulose. For forage sorghum, the 48-h in vitro TDN were 40, 64, and 84 g nutrients digested/100 g organic matter (OM) for raw, short-term OLP, and short-term OLP + ball milling, respectively. In terms of compositional changes, OLP increases NDF and decreases non-fiber carbohydrate (NFC) and crude protein (CP), all of which would normally be associated with a decrease in digestibility. However, because OLP and ball milling beneficially change composition (lignin removal) and structural features (reduced crystallinity), digestibility actually increases. Although ball milling increases digestibility according to standard laboratory assays, it reduces particle size possibly allowing fine particles to escape from the rumen before they are digested, thus limiting its practical application. Nonetheless, this study indicates that mechanical pretreatment greatly increases digestibility, and therefore it is desirable to identify an effective mechanical treatment that retains fiber integrity.


2011 ◽  
Vol 236-238 ◽  
pp. 456-459 ◽  
Author(s):  
Dan Qing Zhao ◽  
Yue Feng ◽  
Li Wei Zhu ◽  
Jian Xin Jiang

Enzymatic hydrolysis constitutes an attractive process configuration for ethanol production from biomass. However, the high enzyme addition contributes to a high process cost. This study shows that appropriate concentration of Gleditsia saponin could reduce the enzyme loading and increase β-glucosidase active. The optimal conditions of enzymatic hydrolysis process of furfural residues was at enzyme loading of 6 FPU cellulose/g substrate and 9 IU β-glucosidase/g substrate with 0.6 g/l of Gleditsia saponin. The enzyme loading could be reduced by 50% with addition of 0.64 g/l Gleditsia saponin during furfural residues hydrolysis. The β-glucosidase activity from hydrolysate with 0.64 g/l Gleditsia saponin was higher than that without any surfactants.


2021 ◽  
Vol 11 (14) ◽  
pp. 6625
Author(s):  
Yan Su ◽  
Kailiang Weng ◽  
Chuan Lin ◽  
Zeqin Chen

An accurate dam deformation prediction model is vital to a dam safety monitoring system, as it helps assess and manage dam risks. Most traditional dam deformation prediction algorithms ignore the interpretation and evaluation of variables and lack qualitative measures. This paper proposes a data processing framework that uses a long short-term memory (LSTM) model coupled with an attention mechanism to predict the deformation response of a dam structure. First, the random forest (RF) model is introduced to assess the relative importance of impact factors and screen input variables. Secondly, the density-based spatial clustering of applications with noise (DBSCAN) method is used to identify and filter the equipment based abnormal values to reduce the random error in the measurements. Finally, the coupled model is used to focus on important factors in the time dimension in order to obtain more accurate nonlinear prediction results. The results of the case study show that, of all tested methods, the proposed coupled method performed best. In addition, it was found that temperature and water level both have significant impacts on dam deformation and can serve as reliable metrics for dam management.


2021 ◽  
pp. 0734242X2110291
Author(s):  
Benjamin Piribauer ◽  
Andreas Bartl ◽  
Wolfgang Ipsmiller

Recently, textiles and their end-of-life management have become the focus of public and political attention. In the European Union the revised waste framework directive defines textiles as municipal waste and stipulates their separate collection by 2025. In the context of these developments, this paper summarises briefly the current state-of-the-art in textile recycling. It is evident that recycling methods are not yet fully developed. This is especially the case with multi-material textiles, which are composed of two or more polymers that are incompatible for recycling. In the practical part of the communication, results are presented which show that enzymatic hydrolysis is a suitable process for recycling textiles made of cotton and polyester. After a complete removal of cotton, the remaining pure polyester fibres undergo a re-granulation and post-condensation step. The so obtained recycled polyester is fed back into the textile processing chain and finally towels are obtained. The main steering parameters of the enzymatic hydrolysis process are described. The study proves that solutions in accordance with the Circular Economy in the textile sector are available but an industrial implementation has not yet been realised.


2015 ◽  
Vol 2015 ◽  
pp. 1-5
Author(s):  
Jeong Heo Kwon ◽  
Siseon Lee ◽  
Jae-Won Lee ◽  
Youn-Woo Hong ◽  
Jeong Ho Chang ◽  
...  

This paper describes an optimization of planetary mill pretreatment and saccharification processes for improving biosugar production. Pitch pine (Pinus rigida) wood sawdust waste was used as biomass feedstock and the process parameters optimized in this study were the buffering media, the milling time, the enzyme quantity, and the incubation time. Glucose yields were improved when acetate buffer was used rather than citrate buffer. Initially, with each process variable tests, the optimal values were 100 minutes of milling, an enzyme concentration of 16 FPU/g-biomass, and a 12-hour enzymatic hydrolysis. Typically, interactions between these experimental conditions and their effects on glucose production were next investigated using RSM. Glucose yields from thePinus rigidawaste exceeded 80% with several of the conditions tested, demonstrating that milling can be used to obtain high levels of glucose bioconversion from woody biomass for biorefinery purposes.


2016 ◽  
Vol 83 (1) ◽  
Author(s):  
Vera BARLIANTI ◽  
Deliana DAHNUM ◽  
. MURYANTO ◽  
Eka TRIWAHYUNI ◽  
Yosi ARISTIAWAN ◽  
...  

Abstrak Sebagai salah satu Negara penghasil minyak kelapa sawit mentah (CPO), Indonesia juga menghasilkan tandan kosong kelapa sawit (TKKS) dalam jumlah besar. TKKS terdiri dari-tiga-komponen utama, yaitu selulosa, hemiselulosa, dan lignin. Pengolahan awal TKKS secara alkalindi ikuti dengan hidrolisis TKKS secara enzimatik menggunakan kombinasi enzim selulase dan β-glukosidase akan menghasilkan gula-gula yang mudah difermentasi.  Penelitian ini bertujuan untuk mempelajari pengaruh konsentrasi substrat, kon-sentrasi enzim, dan suhu selama proses hidrolisis berlangsung.  Hasil yang diperoleh menunjukkan bahwa konsentrasi gula maksimum (194,78 g/L) dicapai pada konsentrasi TKKS 20% (b/v), konsentrasi campuran enzim yang terdiri dari selulase dan β-1,4 glukosidase sebesar 3,85% (v/v), dan suhu 50oC. Perbandingan antara selulase dan β-1,4 glukosidase adalah 5:1 dengan masing-masing aktivitas enzim sebesar 144.5 FPU/mL dan 63 FPU/mL. Hasil penelitian juga menunjukkan bahwa model kinetika yang sesuai untuk proses hidrolisis TKKS secara enzimatik adalah model kinetika Shen dan Agblevor dengan reakside aktivasi enzim orde satu.  Hasil ini mendukung studi kelayakan ekonomi dalam pemanfaatan TKKS untuk produksi bioetanol.AbstractAs one of the crude palm oil producers, Indonesia also produces empty fruit bunches (EFB)in large quantities. The oil palm EFB consist of cellulose, hemicellulose and lignin. Alkaline pretreatment of EFB, followed by enzymatic hydro-lysis of cellulose using combination of cellulase and β-glucosidase enzymes produce fermentable sugars. This paper reported the effects of substrate loading, enzyme concentration, and temperature of hydrolysis process on reducing sugar production. The  maximum  sugar  concentration (194.78 g/L) was produced at 50oC using 20% (w/v) EFB and 3.85% (v/v) mixed enzymes of cellulase and β-1,4 glucosidase in volume ratio of 5:1 (v/v), with enzyme activity of 144.5 FPU/mL and 63 FPU/mL, respectively. The results also showed that the suitable kinetic model for enzymatic hydrolysis process of oil palm EFB follow Shen and Agblevor model with first order of enzyme deactivation. These results support the economic feasibility study in utilization of EFB of oil palm for bioethanol production.    


2021 ◽  
Vol 32 ◽  
pp. 03005
Author(s):  
O. N. Vetrova ◽  
O. Y. Eremina ◽  
N. V. Seregina ◽  
N. V. Shuldeshova

The article presents the results of a study of the enzymatic hydrolysis of barley malt sprouts by cellulolytic enzymes. The influence of the process parameters (temperature, substrate concentration, concentration of the enzyme preparation, duration of the process) on the output of dry substances in the hydrolysate is shown. The results of the experiments were presented by a mathematical model of the process and graphically-in the form of surface projections reflecting the mutual influence of each possible pair of factors on the dry matter content in the hydrolysate. It is found that all the studied factors have an effect on the accumulation of dry substances in the hydrolysate. As a result of optimization the parameters of the enzymatic hydrolysis process, the following parameter values were obtained: temperature - 50 ˚С, duration of enzymatic hydrolysis-89 min, substrate concentration - 0.37 (hydromodule 1:10), concentration of the enzyme preparation - 0.05 %.


2012 ◽  
Vol 93 (8) ◽  
pp. 2061-2070 ◽  
Author(s):  
Farhad Ahmadi ◽  
Abbas Rajaee Rad ◽  
Mark T Holtzapple ◽  
Mohammad Javad Zamiri
Keyword(s):  

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