| 1. |
- Alkasrawi, Malek, et al.
(författare)
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Recirculation of process streams in fuel ethanol production from softwood based on simultaneous saccharification and fermentation
- 2002
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Ingår i: Applied Biochemistry and Biotechnology. - 0273-2289 .- 1559-0291. ; 98, s. 849-861
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Konferensbidrag (refereegranskat)abstract
- The effect of process stream recirculation on ethanol production from steam- pretreated softwood based on simultaneous saccharification and fermentation (SSF) was investigated for two process configurations. In the first configuration, a part of the stillage stream after distillation was recycled and, in the second configuration, the liquid after SSF was recycled. The aim was to minimize the energy consumption in the distillation of the fermentation broth and in the evaporation of the stillage, as well as the use of fresh water. However, recirculation leads to an increased concentration of nonvolatiles in the first configuration, and of both volatiles and nonvolatiles in the second configuration. These substances might be inhibitory to the enzymes and the yeast in SSF. When 60% of the fresh water was replaced by stillage, the ethanol yield and the productivity were the same as for the configuration without recirculation. The ethanol production cost was reduced by 17%. In the second configuration, up to 40% of the fresh water could be replaced without affecting the final ethanol yield, although the initial ethanol productivity decreased. The ethanol production cost was reduced by 12%. At higher degrees of recirculation,fermentation was clearly inhibited, resulting in a decrease in ethanol yield while hydrolysis seemed unaffected.
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| 2. |
- Alriksson, Björn, et al.
(författare)
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Ammonium hydroxide detoxification of spruce acid hydrolysates
- 2005
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Ingår i: Applied Biochemistry and Biotechnology. - 0273-2289 .- 1559-0291. ; 121, s. 911-922
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Tidskriftsartikel (refereegranskat)abstract
- When dilute-acid hydrolysates from spruce are fermented to produce ethanol, detoxification is required to make the hydrolysates fermentable at reasonable rates. Treatment with alkali, usually by overliming, is one of the most efficient approaches. Several nutrients, such as ammonium and phosphate, are added to the hydrolysates prior to fermentation. We investigated the use of NH4OH for simultaneous detoxification and addition of nitrogen source. Treatment with N-H4OH compared favorably with Ca(OH)(2), Mg(OH)(2), Ba(OH)(2), and NaOH to improve fermentability using Saccharomyces cerevisiae. Analysis of monosaccharides, furan aldehydes, phenols, and aliphatic acids was performed after the different treatments. The NH4OH treatments, performed at pH 10.0, resulted in a substantial decrease in the concentrations of furfural and hydroxymethylfurfural. Under the conditions studied, NH4OH treatments gave better results than Ca(OH)(2) treatments. The addition of an extra nitrogen source in the form of NH4Cl at pH 5.5 did not result in any improvement in fermentability that was comparable to NH4OH treatments at alkaline conditions. The addition of CaCl2 or NH4Cl at pH 5.5 after treatment with NH4OH or Ca(OH)(2) resulted in poorer fermentability, and the negative effects were attributed to salt stress. The results strongly suggest that the highly positive effects of NH4OH treatments are owing to chemical conversions rather than stimulation of the yeast cells by ammonium ions during the fermentation.
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| 3. |
- Alriksson, Björn, et al.
(författare)
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Optimal conditions for alkaline detoxification of dilute-acid lignocellulose hydrolysates.
- 2006
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Ingår i: Applied Biochemistry and Biotechnology. - 0273-2289 .- 1559-0291. ; 129-132, s. 599-611
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Tidskriftsartikel (refereegranskat)abstract
- Alkaline detoxification strongly improves the fermentability of dilute-acid hydrolysates in the production of bioethanol from lignocellulose with Saccharomyces cerevisiae. New experiments were performed with NH4OH and NaOH to define optimal conditions for detoxification and make a comparison with Ca(OH)2 treatment feasible. As too harsh conditions lead to sugar degradation, the detoxification treatments were evaluated through the balanced ethanol yield, which takes both the ethanol production and the loss of fermentable sugars into account. The optimization treatments were performed as factorial experiments with 3-h duration and varying pH and temperature. Optimal conditions were found roughly in an area around pH 9.0/60 degrees C for NH4OH treatment and in a narrow area stretching from pH 9.0/80 degrees C to pH 12.0/30 degrees C for NaOH treatment. By optimizing treatment with NH4OH, NaOH, and Ca(OH)2, it was possible to find conditions that resulted in a fermentability that was equal or better than that of a reference fermentation of a synthetic sugar solution without inhibitors, regardless of the type of alkali used. The considerable difference in the amount of precipitate generated after treatment with different types of alkali appears critical for industrial implementation.
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| 4. |
- Ambalam, Padma, et al.
(författare)
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Bile Enhances Cell Surface Hydrophobicity and Biofilm Formation of Bifidobacteria.
- 2014
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Ingår i: Applied Biochemistry and Biotechnology. - : Springer Science and Business Media LLC. - 1559-0291 .- 0273-2289. ; 172:4, s. 1970-1981
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Tidskriftsartikel (refereegranskat)abstract
- Twenty-four human bifidobacterial strains were analysed for cell surface hydrophobicity (CSH) using a salt aggregation test (SAT) and a Congo red binding (CRB) assay. Three strains were selected for a systematic study on the CSH and biofilm formation: Bifidobacterium breve 46, Bifidobacterium animalis ssp. lactis 8:8 and a reference strain B. animalis ssp. lactis JCM 10602. CRB of the B. breve 46 and B. animalis ssp. lactis JCM 10602 was significantly enhanced (P < 0.05) when grown in deMan-Rogosa-Sharpe cysteine (MRSC) broth supplemented with taurocholic acid (TA) or native porcine bile (PB). An enhanced CSH of the strains grown with PB and gastric mucin correlated with an increased mucin binding and an enhanced biofilm formation in prebiotic oligosaccharide-supplemented cultures. The three strains showed late bile-induced biofilm (72 h) under an anaerobic growth condition, and both B. animalis ssp. lactis strains showed a late bile-induced biofilm formation under aerobic conditions shown by crystal violet staining. These two strains were thus considered to be oxygen tolerant and more robust. Furthermore, enhanced biofilm formation of these robust bifidobacterial strains in the presence of prebiotics may allow for strong colonisation in the gastrointestinal tract when administered to in vivo models as a "synbiotic supplement".
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| 5. |
- Andersson, Alexandra, et al.
(författare)
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Comparison of diafiltration and size-exclusion chromatography to recover hemicelluloses from process water from thermomechanical pulping of spruce
- 2007
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Ingår i: Applied Biochemistry and Biotechnology. - : Springer Science and Business Media LLC. - 1559-0291 .- 0273-2289. ; 137:1-12, s. 971-983
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Tidskriftsartikel (refereegranskat)abstract
- Hemicelluloses constitute one of the most abundant renewable resources on earth. To increase their utilization, the isolation of hemicelluloses from industrial biomass side-streams would be beneficial. A method was investigated to isolate hemicelluloses from process water from a thermomechanical pulp mill. The method consists of three steps: removal of solids by microfiltration, preconcentration of the hemicelluloses by ultrafiltration, and purification by either size-exclusion chromatography (SEC) or diafiltration. The purpose of the final purification step is to separate hemicelluloses from small oligosaccharides, monosaccharides, and salts. The ratio between galactose, glucose, and mannose in oligo- and polysaccharides after preconcentration was 0.8: 1: 2.8, which is similar to that found in galactoglucomannan. Continuous diafiltration was performed using a composite fluoro polymer membrane with cutoff of 1000 Da. After diafiltration with four diavolumes the purity of the hemicelluloses was 77% (gram oligo- and polysaccharides/gram total dissolved solids) and the recovery was 87%. Purification by SEC was performed with 5, 20, and 40% sample loadings, respectively and a flow rate of 12 or 25 mL/min (9 or 19 cm/h). The purity of hemicelluloses after SEC was approx 82%, and the recovery was above 99%. The optimal sample load and flow rate were 20% and 25 mL/min, respectively. The process water from thermomechanical pulping of spruce is inexpensive. Thus, the recovery of hemicelluloses is not of main importance. If the purity of 77%, obtained with diafiltration, is sufficient for the utilization of the hemicelluloses, diafiltration probably offers a less expensive alternative in this application.
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| 6. |
- Arpitha, Ashok, et al.
(författare)
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Inhibition of Snake Venom Metalloproteinase by β-Lactoglobulin Peptide from Buffalo (Bubalus bubalis) Colostrum
- 2017
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Ingår i: Applied Biochemistry and Biotechnology. - : Springer Science and Business Media LLC. - 0273-2289 .- 1559-0291. ; 182:4, s. 1415-1432
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Tidskriftsartikel (refereegranskat)abstract
- Bioactive peptide research has experienced considerable therapeutic interest owing to varied physiological functions, efficacy in excretion, and tolerability of peptides. Colostrum is a rich natural source of bioactive peptides with many properties elucidated such as anti-thrombotic, anti-hypertensive, opioid, immunomodulatory, etc. In this study, a variant peptide derived from β-lactoglobulin from buffalo colostrum was evaluated for the anti-ophidian property by targeting snake venom metalloproteinases. These are responsible for rapid local tissue damages that develop after snakebite such as edema, hemorrhage, myonecrosis, and extracellular matrix degradation. The peptide identified by LC-MS/MS effectively neutralized hemorrhagic activity of the Echis carinatus venom in a dose-dependent manner. Histological examinations revealed that the peptide mitigated basement membrane degradation and accumulation of inflammatory leucocytes at the venom-injected site. Inhibition of proteolytic activity was evidenced in both casein and gelatin zymograms. Also, inhibition of fibrinolytic and fibrinogenolytic activities was seen. The UV-visible spectral study implicated Zn2+ chelation, which was further confirmed by molecular docking and dynamic studies by assessing molecular interactions, thus implicating the probable mechanism for inhibition of venom-induced proteolytic and hemorrhagic activities. The present investigation establishes newer vista for the BLG-col peptide with anti-ophidian efficacy as a promising candidate for therapeutic interventions.
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| 7. |
- Aslanzadeh, Solmaz, et al.
(författare)
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Biogas Production from N-Methylmorpholine-N-oxide (NMMO) Pretreated Forest Residues
- 2014
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Ingår i: Applied Biochemistry and Biotechnology. - : Humana Press, Inc.. - 0273-2289 .- 1559-0291. ; 172:6, s. 2998-3008
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Tidskriftsartikel (refereegranskat)abstract
- Lignocellulosic biomass represents a great potential for biogas production. However, a suitable pretreatment is needed to improve their digestibility. This study investigates the effects of an organic solvent, N-Methylmorpholine-N-oxide (NMMO) at temperatures of 120 and 90 °C, NMMO concentrations of 75 and 85 % and treatment times of 3 and 15 h on the methane yield. The long-term effects of the treatment were determined by a semicontinuous experiment. The best results were obtained using 75 % NMMO at 120 °C for 15 h, resulting in 141 % increase in the methane production. These conditions led to a decrease by 9 % and an increase by 8 % in the lignin and in the carbohydrate content, respectively. During the continuous digestion experiments, a specific biogas production rate of 92 NmL/gVS/day was achieved while the corresponding rate from the untreated sample was 53 NmL/gVS/day. The operation conditions were set at 4.4 gVS/L/day organic loading rate (OLR) and hydraulic retention time (HRT) of 20 days in both cases. NMMO pretreatment has substantially improved the digestibility of forest residues. The present study shows the possibilities of this pretreatment method; however, an economic and technical assessment of its industrial use needs to be performed in the future.
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| 8. |
- Benko, Zsuzsa, et al.
(författare)
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Heat extraction of corn fiber hemicellulose
- 2007
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Ingår i: Applied Biochemistry and Biotechnology. - : Springer Science and Business Media LLC. - 1559-0291 .- 0273-2289. ; 137, s. 253-265
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Tidskriftsartikel (refereegranskat)abstract
- Water-soluble hemicellulose was extracted from corn fiber with microwave-assisted heat treatment. The effects of treatment temperature and initial pH of the aqueous extraction media were investigated regarding hemicellulose recovery and molecular mass of the isolated polysaccharides. In treatments carried out at neutral pH (simple water extraction), it has been demonstrated that hemicellulose recovery could be increased by applying higher treatment temperatures. However, the molecular weight of isolated hemicellulose gets significantly lower. For example, 10% of the raw materials' xylan was extracted at 160 degrees C and about 30% recovery was reached at 210 degrees C. However, the molecular mass of the isolated polysaccharide at 210 degrees C (5.82 x 10(4)) was about half of that measured at 160 degrees C (1.37 x 10(5)). Reducing the pH with sulfuric acid resulted in shorter polymer chains (1.7 x 10(4)) and lower hemicellulose yields (2.2%). Application of sodium hydroxide in the treatment showed that, compared with acid, considerably higher yields (11%) with longer polysaccharide chains (1.3 x 10(5)) could be obtained.
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| 9. |
- Bergdahl, Gizem Ertürk, et al.
(författare)
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Capacitive Saccharide Sensor Based on Immobilized Phenylboronic Acid with Diol Specificity
- 2019
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Ingår i: Applied Biochemistry and Biotechnology. - : Springer Science and Business Media LLC. - 0273-2289 .- 1559-0291. ; 188:1, s. 124-137
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Tidskriftsartikel (refereegranskat)abstract
- A capacitive sensor for saccharide detection is described in this study. The detection is based on selective interaction between diols and aminophenylboronic acid (APBA) immobilized on a gold electrode. Glucose, fructose, and dextran (MW: 40 kDa) were tested with the system over wide concentration ranges (1.0 x 10−8 M - 1.0 x 10−3 M for glucose, 1.0 x 10−8 M - 1.0 x 10−2 M for fructose and 1.0 x 10−10 M - 1.0 x 10−5 M for dextran). The limits of detection (LODs) were 0.8 nM for glucose, 0.6 nM for fructose, and 13 pM for dextran. These data were comparable to the others reported previously. In order to demonstrate glycoprotein detection with the same sensor, human immunoglobulin G (IgG) as well as horseradish peroxidase were used as model analytes. The sensor responded to IgG in the concentration range of 1.0 x 10−13 M - 1.0 x 10−7 M with a LOD value of 16 fM. The performance of the assay of peroxidase was compared to a spectrophotometric assay by determining the enzymatic activity of a captured analyte. The results showed that the method might be useful for label-free, fast, and sensitive detection of saccharides as well as glycoproteins over a wide concentration range.
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| 10. |
- Bergdahl, Gizem Ertürk, et al.
(författare)
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Capacitive Sensor to Monitor Enzyme Activity by Following Degradation of Macromolecules in Real Time
- 2019
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Ingår i: Applied Biochemistry and Biotechnology. - : Springer Science and Business Media LLC. - 0273-2289 .- 1559-0291. ; 189, s. 374-383
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Tidskriftsartikel (refereegranskat)abstract
- A capacitive sensor was developed to analyze the presence and enzymatic activity of a model protease from standard solutions by following the degradation of the substrate in real time. The enzyme was chosen based on its specific digestion of the hinge region of immunoglobulin G (IgG). Real-time enzyme activity was monitored by measuring the change in capacitance (∆C) based on the release of IgG fragments after enzymatic digestion by the enzyme. The results indicated that the developed capacitive system might be used successfully for label-free and real-time monitoring of enzymatic activity of different enzymes in a sensitive, rapid, and inexpensive manner in biotechnological, environmental, and clinical applications.
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