169 research outputs found
Alkaline protease production by solid state fermentation on polyurethane foam
This paper investigated the process of solid state fermentation (SSF) using PUF (polyurethane foam) as inert solid support to produce alkaline protease. Maximal enzyme activity was 2185U/ml at pH 9.0, incubation temperature 32 0C inoculum amount of 1.0 % (v/v) , nutrient solution3.75 ml/g PUF, incubation time for 2 h and 15.0 mM of added CaCl2. Under the same conditions, the yield of alkaline protease produced by SSF using PUF as support is higher than that by submerged fermentation (SMF)
Identification of novel immune-related targets mediating disease progression in acute pancreatitis
IntroductionAcute pancreatitis (AP) is an inflammatory disease with very poor outcomes. However, the order of induction and coordinated interactions of systemic inflammatory response syndrome (SIRS) and compensatory anti-inflammatory response syndrome (CARS) and the potential mechanisms in AP are still unclear.MethodsAn integrative analysis was performed based on transcripts of blood from patients with different severity levels of AP (GSE194331), as well as impaired lung (GSE151572), liver (GSE151927) and pancreas (GSE65146) samples from an AP experimental model to identify inflammatory signals and immune response-associated susceptibility genes. An AP animal model was established in wild-type (WT) mice and Tlr2-deficient mice by repeated intraperitoneal injection of cerulein. Serum lipase and amylase, pancreas impairment and neutrophil infiltration were evaluated to assess the effects of Tlr2 in vivo.ResultsThe numbers of anti-inflammatory response-related cells, such as M2 macrophages (P = 3.2 × 10–3), were increased with worsening AP progression, while the numbers of pro-inflammatory response-related cells, such as neutrophils (P = 3.0 × 10–8), also increased. Then, 10 immune-related AP susceptibility genes (SOSC3, ITGAM, CAMP, FPR1, IL1R1, TLR2, S100A8/9, HK3 and MMP9) were identified. Finally, compared with WT mice, Tlr2-deficient mice exhibited not only significantly reduced serum lipase and amylase levels after cerulein induction but also alleviated pancreatic inflammation and neutrophil accumulation.DiscussionIn summary, we discovered SIRS and CARS were stimulated in parallel, not activated consecutively. In addition, among the novel susceptibility genes, TLR2might be a novel therapeutic target that mediates dysregulation of inflammatory responses during AP progression
Process Biochem.
This work studied the feasibility of near-infrared spectroscopy (NIRS) with a fiber-optic probe for the prediction of state variables in solid-state fermentation (SSF) samples with neither previous treatment nor manipulation. The models were developed using 50 samples and had the following root mean square error of cross-validation (RMSECV): 0.0253 for moisture content, 4.720 mg/g wet medium for biomass, 3.51 FPA/g wet medium for cellulase. Ten external samples were used to test the stability of the prediction models. The maximum absolute error and maximum relative error (%) were 0.0372 and 5.86 for moisture content, -6.51 and 11.63 for biomass, and 2.26 and 8.52 for cellulase. The predicted values using the NIRS technology were similar to the values obtained using chemical methods. (C) 2008 Elsevier Ltd. All rights reserved.This work studied the feasibility of near-infrared spectroscopy (NIRS) with a fiber-optic probe for the prediction of state variables in solid-state fermentation (SSF) samples with neither previous treatment nor manipulation. The models were developed using 50 samples and had the following root mean square error of cross-validation (RMSECV): 0.0253 for moisture content, 4.720 mg/g wet medium for biomass, 3.51 FPA/g wet medium for cellulase. Ten external samples were used to test the stability of the prediction models. The maximum absolute error and maximum relative error (%) were 0.0372 and 5.86 for moisture content, -6.51 and 11.63 for biomass, and 2.26 and 8.52 for cellulase. The predicted values using the NIRS technology were similar to the values obtained using chemical methods. (C) 2008 Elsevier Ltd. All rights reserved
Process Biochem.
Steam explosion (SE) is widely used in lignocellulose pretreatment. However, steam-exploded corn straw (SECS) cannot be directly used as a solid-state fermentation substrate for Trichoderma reesei owing to the inhibitors released during pretreatment. We investigated the effect of SE conditions on inhibitor production in a 5 m(3) SE reactor and the fermentation enhancement achieved by drying and waterwashing of SECS. The results reveal that SE enhanced the fermentability of corn straw and simultaneously produced fermentation inhibitors. Water-washing (corn straw/water 1:5, 60 degrees C, 2 x 30 min) removed 81% of the furfural and 85% of the phenol compounds from SECS pretreated at 1.6 MPa, which were higher than the 46 and 8.1%, respectively, removed by drying at 105 degrees C for 2 It. T reesei YG3 cultures produced high cellulase activity of 41.4 and 81.4 IU/g dry medium on dried and water-washed SECS, respectively, which is higher than the 2.2 IU/g dry medium obtained from corn straw. (c) 2008 Elsevier Ltd. All rights reserved.Steam explosion (SE) is widely used in lignocellulose pretreatment. However, steam-exploded corn straw (SECS) cannot be directly used as a solid-state fermentation substrate for Trichoderma reesei owing to the inhibitors released during pretreatment. We investigated the effect of SE conditions on inhibitor production in a 5 m(3) SE reactor and the fermentation enhancement achieved by drying and waterwashing of SECS. The results reveal that SE enhanced the fermentability of corn straw and simultaneously produced fermentation inhibitors. Water-washing (corn straw/water 1:5, 60 degrees C, 2 x 30 min) removed 81% of the furfural and 85% of the phenol compounds from SECS pretreated at 1.6 MPa, which were higher than the 46 and 8.1%, respectively, removed by drying at 105 degrees C for 2 It. T reesei YG3 cultures produced high cellulase activity of 41.4 and 81.4 IU/g dry medium on dried and water-washed SECS, respectively, which is higher than the 2.2 IU/g dry medium obtained from corn straw. (c) 2008 Elsevier Ltd. All rights reserved
Biomass Bioenerg.
Pretreatment was the essential step for industrial application of lignocellulosic biomass. Combination of steam explosion and fungal treatment was conducted, and synergistic mechanism of the combined pretreatment was evaluated in terms of pore size distribution, crystallinity index, chemical compositions and enzymatic hydrolysis. The results showed that steam explosion destroyed the rigid structure of corn stalk, increased pore size and porosity, and exposed crystalline component of cellulose. Steam explosion broke the lignin-carbohydrate-complex structure of lignocellulosic biomass and facilitated the fungal treatment. Phellinus bawnii could selectively degrade 34.7% and 36.58% of lignin for 1.4 MPa and 1.7 MPa steam-exploded corn stalk, respectively. As a result, the highest glucose yield of corn stalk pretreated by the condition of 1.7 MPa steam explosion associated with 21 d P. baumii reached 313.31 g kg(-1), which was 2.88 and 1.32 times higher than that of the untreated corn stalk and the 1.7 MPa steam-exploded corn stalk, respectively. The combined pretreatment enhanced the enzymatic hydrolysis, which was a promising technology that might be explored as alternative to the existing pretreatment. (C) 2014 Elsevier Ltd. All rights reserved.Pretreatment was the essential step for industrial application of lignocellulosic biomass. Combination of steam explosion and fungal treatment was conducted, and synergistic mechanism of the combined pretreatment was evaluated in terms of pore size distribution, crystallinity index, chemical compositions and enzymatic hydrolysis. The results showed that steam explosion destroyed the rigid structure of corn stalk, increased pore size and porosity, and exposed crystalline component of cellulose. Steam explosion broke the lignin-carbohydrate-complex structure of lignocellulosic biomass and facilitated the fungal treatment. Phellinus bawnii could selectively degrade 34.7% and 36.58% of lignin for 1.4 MPa and 1.7 MPa steam-exploded corn stalk, respectively. As a result, the highest glucose yield of corn stalk pretreated by the condition of 1.7 MPa steam explosion associated with 21 d P. baumii reached 313.31 g kg(-1), which was 2.88 and 1.32 times higher than that of the untreated corn stalk and the 1.7 MPa steam-exploded corn stalk, respectively. The combined pretreatment enhanced the enzymatic hydrolysis, which was a promising technology that might be explored as alternative to the existing pretreatment. (C) 2014 Elsevier Ltd. All rights reserved
Bioresour. Technol.
Improving nitrogen content and enhancing enzymatic hydrolysis are key processes involved in cellulosic ethanol production. Steam explosion (SE) associated with NH4Cl preimpregnation was carried out to investigate effects of the pretreatment on nitrogen content, enzymatic digestibility, and ethanol production. Results showed that nitrogen content in pretreated samples increased, which can be used as nitrogen resource for ethanol fermentation. The highest glucose yield of sample pretreated by 1.4 MPa SE with 90 g/l NH4Cl preimpregnation was 62.64%, which was 2.1 and 0.2 times higher than that of untreated sample and 1.4 MPa SE pretreated sample, respectively. Ethanol yield of sample pretreated by 1.1 MPa SE with 135 g/l NH4Cl preimpregnation resulted in 1.93 and 0.69 times higher than that of untreated sample and 1.1 MPa SE pretreated sample, respectively. This novel pretreatment improved nitrogen content and enhanced enzymatic digestibility under mild conditions, and could be recommended to further industrial application. (C) 2013 Elsevier Ltd. All rights reserved.Improving nitrogen content and enhancing enzymatic hydrolysis are key processes involved in cellulosic ethanol production. Steam explosion (SE) associated with NH4Cl preimpregnation was carried out to investigate effects of the pretreatment on nitrogen content, enzymatic digestibility, and ethanol production. Results showed that nitrogen content in pretreated samples increased, which can be used as nitrogen resource for ethanol fermentation. The highest glucose yield of sample pretreated by 1.4 MPa SE with 90 g/l NH4Cl preimpregnation was 62.64%, which was 2.1 and 0.2 times higher than that of untreated sample and 1.4 MPa SE pretreated sample, respectively. Ethanol yield of sample pretreated by 1.1 MPa SE with 135 g/l NH4Cl preimpregnation resulted in 1.93 and 0.69 times higher than that of untreated sample and 1.1 MPa SE pretreated sample, respectively. This novel pretreatment improved nitrogen content and enhanced enzymatic digestibility under mild conditions, and could be recommended to further industrial application. (C) 2013 Elsevier Ltd. All rights reserved
An industrial level system with nonisothermal simultaneous solid state saccharification, fermentation and separation for ethanol production
To alleviate the problems of low substrate loading, nonisothermal, end-product inhibition of ethanol during the simultaneous saccharification and fermentation, a nonisothermal simultaneous solid state saccharification, fermentation, and separation (NSSSFS) process was investigated; one novel pilot scale nonisothermal simultaneous solid state enzymatic saccharification and fermentation coupled with CO2 gas stripping loop system was invented and tested. The optimal pretreatment condition of steam-explosion was 1.5 MPa for 5 min in industrial level. In the NSSSFS, enzymatic saccharification and fermentation proceeded at around 50 degrees C and 37 degrees C, respectively, and were coupled together by the hydrolyzate loop; glucose from enzymatic saccharification was timely consumed by yeast, and the formed ethanol was separated online by CO2 gas stripping coupled with adsorption of activated carbon; the solids substrate loading reached 25%; ethanol yields from 18.96% to 30.29% were obtained in fermentation depending on the materials tested. Based on the pilot level of 300 L fermenter, a novel industrial-level of 110 m(3) solid state enzymatic saccharification, fermentation and ethanol separation plant had been successfully established and operated. The NSSSFS was a novel and feasible engineering solution to the inherent problems of simultaneous saccharification and fermentation, which would be used in large scale and in industrial production of ethanol. (C) 2013 Elsevier B.V. All rights reserved
Int. J. Hydrog. Energy
Hydrogen was produced by simultaneous saccharification and fermentation from steam-exploded corn straw (SECS) using Clostridium butyricum AS 1.209. Effect of various process parameters, such as solid to liquid ratio, enzyme loading and initial pH, etc., were examined with respect to maximum hydrogen productivity which was obtained by fitting the cumulative hydrogen production data to a modified Gompertz equation. Maximum specific hydrogen production rate and maximal hydrogen yield were 126 ml/g VSS d and 68 ml/g SECS, respectively. The yield of soluble metabolites was 197.7 mg/g SECS. Acetic acid accounted for 46% of the total was the most abundant product and this shows that hydrogen production from SECS was essentially acetate-type fermentation. Hydrogen production by simultaneous saccharification and fermentation of SECS has the predominance of short lag-stage and high maximum specific hydrogen production rate and it was a promising method for hydrogen production and straw biomass conversion. (C) 2007 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.Hydrogen was produced by simultaneous saccharification and fermentation from steam-exploded corn straw (SECS) using Clostridium butyricum AS 1.209. Effect of various process parameters, such as solid to liquid ratio, enzyme loading and initial pH, etc., were examined with respect to maximum hydrogen productivity which was obtained by fitting the cumulative hydrogen production data to a modified Gompertz equation. Maximum specific hydrogen production rate and maximal hydrogen yield were 126 ml/g VSS d and 68 ml/g SECS, respectively. The yield of soluble metabolites was 197.7 mg/g SECS. Acetic acid accounted for 46% of the total was the most abundant product and this shows that hydrogen production from SECS was essentially acetate-type fermentation. Hydrogen production by simultaneous saccharification and fermentation of SECS has the predominance of short lag-stage and high maximum specific hydrogen production rate and it was a promising method for hydrogen production and straw biomass conversion. (C) 2007 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved
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