scholarly journals Using poly(N-Vinylcaprolactam) to Improve the Enzymatic Hydrolysis Efficiency of Phenylsulfonic Acid-Pretreated Bamboo

Author(s):  
Xianqing Lv ◽  
Guangxu Yang ◽  
Zhenggang Gong ◽  
Xin Cheng ◽  
Li Shuai ◽  
...  

Chemical pretreatment followed by enzymatic hydrolysis has been regarded as a viable way to produce fermentable sugars. Phenylsulfonic acid (PSA) pretreatment could efficiently fractionate the non-cellulosic components (hemicelluloses and lignin) from bamboo and result in increased cellulose accessibility that was 10 times that of untreated bamboo. However, deposited lignin could trigger non-productive adsorption to enzymes, which therefore significantly decreased the enzymatic hydrolysis efficiency of PSA-pretreated bamboo substrates. Herein, poly(N-vinylcaprolactam) (PNVCL), a non-ionic surfactant, was developed as a novel additive for overcoming the non-productive adsorption of lignin during enzymatic hydrolysis. PNVCL was found to be not only more effective than those of commonly used lignosulfonate and polyvinyl alcohol for overcoming the negative effect of lignin, but also comparable to the robust Tween 20 and bovine serum albumin additives. A PNVCL loading at 1.2 g/L during enzymatic hydrolysis of PSA pretreated bamboo substrate could achieve an 80% cellulosic enzymatic conversion and meanwhile reduce the cellulase loading by three times as compared to that without additive. Mechanistic investigations indicated that PNVCL could block lignin residues through hydrophobic interactions and the resultant PNVCL coating resisted the adsorption of cellulase via electrostatic repulsion and/or hydration. This practical method can improve the lignocellulosic enzymatic hydrolysis efficiency and thereby increase the productivity and profitability of biorefinery.

2014 ◽  
Vol 34 (1) ◽  
pp. 167-173 ◽  
Author(s):  
Aikaterini I. Vavouraki ◽  
Vassiliki Volioti ◽  
Michael E. Kornaros

1977 ◽  
Vol 23 (2) ◽  
pp. 139-147 ◽  
Author(s):  
D. Sternberg ◽  
P. Vuayakumar ◽  
E. T. Reese

The enzymatic conversion of cellulose is catalyzed by a multiple enzyme system. The Trichoderma enzyme system has been studied extensively and has insufficient β-glucosidase (EC 3.2.1.21) activity for the practical saccharification of cellulose. The black aspergilli (A. niger and A. phoenicis) were superior producers of β-glucosidase and a method for production of this enzyme in liquid culture is presented. When Trichoderma cellulase preparations are supplemented with β-glucosidase from Aspergillus during practical saccharifications, glucose is the predominant product and the rate of saccharification is significantly increased. The stimulatory effect of β-glucosidase appears to be due to the removal of inhibitory levels of cellobiose.


Author(s):  
Mehdi Ashraf-Khorassani ◽  
William M. Coleman ◽  
Michael F. Dube ◽  
Larry T. Taylor

SummaryFree amino acids have been isolated via optimized enzymatic hydrolysis of F1 tobacco protein using two cationic resins (Amberlite IR120 and Dowex MAC-2). Optimized enzymatic conversions of the protein as a result of systematic variations in conditions (e.g., time, temperature, pH, enzyme type, enzyme concentration, anaerobic/aerobic environments, and protein concentration) employing commercially available enzymes, were consistently higher than 50% with qualitative amino acid arrays that were consistent with the known composition of tobacco F1 protein. Amberlite IR120 was shown to have a much higher efficiency and capacity for isolation of amino acids from standard solutions and from hydrolysate when compared with the results using Dowex MAC-2. Two columns packed with conditioned Amberlite IR120 (120 × 10 mm,12–15 g resin) and (200 × 25.4 mm, 60–65 g resin) were used to isolate two batches (2.5–3.0 mg and 13–15 mg) of free amino acids, respectively. A relatively inexpensive analytical methodology was developed for rapid analysis of the free amino acids contained within the enzyme hydrolysate. Commercially available enzymes, when employed in optimized reaction conditions, are very effective for enzymatic conversion of tobacco F1 protein to free amino acids.


2012 ◽  
Vol 126 ◽  
pp. 208-215 ◽  
Author(s):  
Magnus Wiman ◽  
Dora Dienes ◽  
Mads A.T. Hansen ◽  
Torbjörn van der Meulen ◽  
Guido Zacchi ◽  
...  

2013 ◽  
Vol 13 (1) ◽  
pp. 53-58 ◽  
Author(s):  
Teuku Beuna Bardant ◽  
Sudiyarmanto Sudiyarmanto ◽  
Haznan Abimanyu ◽  
Aisha Kania Hanum

Enzymatic hydrolysis with high substrate loading of palm oil (Elaeis guineensis) empty fruit bunch (EFB) and water-hyacinth (Eichhornia crassipes) were investigated as a prior part of ethanol production from lignocelluloses. Commercial surfactant Span 85 and Tween 20 were used as cellulase performance enhancer in hydrolysis process with substrate loading above 20% (w/w). Cellulase performances were compared based on hydrolysis conversion. Hydrolysis conversions of EFB using cellulase with concentration 10 and 15 FPU/g-substrate was 38.55% and 88.80% respectively. Addition 2% (v/v) of Tween 20 to EFB hydrolysis reaction with cellulase concentration 10 FPU/g-substrate gave the conversion 87.30%. This addition enhance the cellulase performance up to 226.5% or similar with the performance of cellulase 15 FPU/g substrate. Addition 2% (v/v) of Span 85 to the similar reaction only enhances cellulase performance to 174.7%. Hydrolysis conversion of boiling-pretreated water-hyacinth and autoclave-pretreated water-hyacinth using cellulase 15 FPU/g-substrate was 45.84% and 52.29% respectively. Addition 2% (v/v) of Tween 20 and Span 85 to boiling-pretreated water-hyacinth hydrolysis with cellulase concentration 15 FPU/g-substrate enhance cellulase performance of 128.9% and 153.5% respectively. Addition 1% (v/v) of Tween 20 and Span 85 to the similar reaction with cellulase concentration 10 FPU/g-substrate gave conversions 51.00% and 53.79% respectively, or similar with conversion of autoclave-pretreated water-hyacinth hydrolysis with 15 FPU/g-substrate.


2018 ◽  
Vol 6 (2) ◽  
pp. 609
Author(s):  
S Saraswati

The resources and reserves of oil which is a non renewable energy are very limited, while the oil consumption is increasing continuously. It is necessary to look for alternative energy. Etanol, a liquid energy, is a renewable alternative energy. Glucose can be used as raw material for etanol production. Glucose can be obtained by enzymatic hydrolysis of bagasse which is a solid waste of sugar canefactory. The objective of this research was to get the optimum condition of etanol production using bagasse as raw material. The experimental research consisted of 2 steps. First step : enzymatic hydrolysis of bagasse with chemical pretreatment process, and the second step was fermentation process using Zymomonas mobilis bacteria. Variables of thefirst step were the NaOH concentration (5%, 7% and 9%) as a pretreatment agent, and cellulase enzyme used (30, 40 and 50 cellulase enzyme  units/gram bagasse). For the second step, the variables were glucose concentration (I2.5%, 15%, 20%, 22.5%, and 25%) and the fermentation time (20, 24, 28, 32, 36, 40 and 48 hours). The experiment showed that the best result of the enzymatic hydrolysis could be obtained by NaOH 7% as chemical pretreatment agent and using 50 units of cellulase enzyme/gram bagasse. The cellulose conversion of bagasse was 87% within 42 hours period time. The highest etanol concentration of the fermentation process was 9.238% (weight %) and the yield was 0.4912 grams etanol/gram glucose. It was reached by using 22.5% glucose during 48 hours fermentation  time.Keywords: etanol; fermentation; Zymomonas mobilis; glucose; hydrolysis; cellulase enzyme; pretreatment;bagasse AbstrakCadangan minyak bumi yang merupakan non renewable energy (energi tak terbarukan) sangat terbatas, sedang konsumsinya terus meningkat.  Untuk itu perlu  dicari energi alternatif. Etanol merupakan salah satu energi cair alternatif yang terbarukan (renewable). Bahan baku etanol antara lain adalah glukosa. Glukosa dapat diperoleh dari hidrolisa enzimatik bagas yang merupakan limbah pabrik gula. Penelitian ini bertujuan  untuk  mendapatkan  kondisi yang  optimum  dari pembuatan  etanol  dengan  bahan baku bagas. Penelitian  experimental  meliputi  dua tahap.  Tahap I  : proses  hidrolisa  enzimatik  dari bagas dengan perlakuan pendahuluan  (pretreatment), dan tahap II adalah proses fermentasi  dengan bakteri Zymomonas  mobilis.  Variabel pada  tahap I  adalah  konsentrasi  NaOH  sebagai  pretreatment   agent sebesar 5%, 7% dan 9% serta pemakaian enzim selulase : 30, 40 dan 50 unit enzim selulase/gram bagas. Variabel untuk tahap II  adalah konsentrasi glukosa:  12.5%,  15%, 20%, 22.5%  dan 25% dan waktu fermentasi  20, 24, 28, 32, 36, 40  dan 48 jam.  Hasil penelitian  menunjukkan  bahwa  untuk  hidrolisa enzimatik hasil yang terbaik diperoleh dengan NaOH 7% dan 50 unit enzim selulase/gram bagas dengan konversi selulosa 87% dan waktu 42 jam. Untuk fermentasi kadar etanol tertinggi diperoleh pada konsentrasi glukosa 22.5% yaitu sebesar 9.238%, waktu 48 jam dan yield 0.4912 gram etanollgram glukosa.Kata Kunci: etanol; fennentasi; Zymomonas mobilis; glukosa; hidrolisa ; enzim selulase; pretreatment; bagas.


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