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[en] Low yields and productivity in fermentation industry usually due to poor quality of seed culture (inoculum). As the first stage in the fermentation process, inoculum consistency in terms of size and quality is clearly important for high yield of enzymes production. Selection of microorganism also plays an important role in improving the productivity. Fungi type of white rot basidiomycetes species is a well-known cellulolytic enzymes producer and capable to degrade many types of lignocellulosic biomass. Cellulolytic enzymes produced from white rot fungi, Pycnoporus sanguineus (PS) were investigated. The PS cultured on different agar media and parameter conditions of seed culture preparation in liquid medium broth were compared. Seed culture conditions of PS were influenced by many factors such as type of medium used for fungal growth, temperature, incubation time in liquid medium and subculture time on agar medium. PS was full-grown on potato dextrose agar (PDA) on day 5 compared to malt extract agar (MEA) on day 7. Seed culture conditions was determined using standard liquid medium, potato dextrose broth (PDB) at constant temperature (30 degree Celsius), agitation speed (150 rpm) and pH (4.8) for duration of seven days using two different subculture of PS that were grown for five and seven days. It was found that the five days subculture of PS shown 3.93 % higher cell dry weight of fungal biomass (3.44 g/ L on day 5) and higher cellulolytic enzymes activity; 95.49 % (FPase), 3.14 % (CMCase), 7.71 % (exoglucanases) and 14.93 % (xylanases). Maximum cellulolytic enzymes were found after 48 hours incubation with filter paper activity (FPase) of 1.79 U/ mL, carboxymethyl cellulase activity (CMCase) of 3.36 U/ mL, exoglucanase activity (Avicelase) of 0.59 U/ mL and xylanase enzymes activity of 0.66 U/ mL. Reducing sugars concentration decreased from day 1 to 7 due to consumption of sugars for fungal growth. Seed culture conditions were strongly influenced by subculture and incubation time in liquid medium to produce high yield of cellulolytic enzymes from PS. (author)
[en] To assess the role of polyphenol oxidase (PPO), peroxidase (POD) and indole-3-acetic acid oxidase (IAAox) during adventitious rooting (Ar) in semi-hardwood cuttings of the easy-to-root olive cv. ‘Arbequina’ and the difficult-to-root cv. ‘Kalamata’. Simultaneously, a histological study was carried out in both cultivars to investigate the tissue related with Ar development. The rooting experiments were carried out in ‘Kostelenos’ nurseries (Troizinia, Greece) and in Agricultural University of Athens. Plant material to set up the experiment was collected from current year shoots from 15-year-old mother plants of ‘Arbequina’ and ‘Kalamata’ at three different seasons (summer, autumn and spring). The auxin indole-3-butyric acid (IBA) at 2000 mg L-1 was used as rooting inducer. Main results: Analysis revealed that ‘Kalamata’ had significantly higher enzymatic activities before experiment onset and during Ar compared to ‘Arbequina’. Control cuttings of both cultivars exhibited increased enzymatic activities compared to IBA treated ones. IAAox was on average three times higher in ‘Kalamata’ than in ‘Arbequina’ and exhibited significant peaks during Ar. Similar peaks of POD and PPO activities were also detected. Histological analyses in ‘Kalamata’ revealed a continuous sheath of sclerenchyma ring and increased cortex thickness. Significant cell proliferation occurred in the phloem region in ‘Arbequina’ 15 days after planting and afterwards the root initials started developing in the secondary phloem from cambial cells.
[en] Highlights: • MIBK/H2O pretreatment with biphasic system was applied to treat Eucalyptus. • Treatment condition had obvious effect on yield of furfural and glucose conversion. • Optimum condition was obtained (VMIBK:VH2O = 5:5, 150 °C, 60 min, 0.3 M HCl). • MIBK/H2O pretreatment was effective for production of clean energy and biochemical. - Abstract: Forest wood biomass can be a sustainable and cost-effective feedstock for the biorefinery industries, but the rigid and compact structure of plant cell is a major barrier for production of clean energy and biochemical. In this case, the MIBK/H2O pretreatment with biphasic system was applied to treat Eucalyptus and then systematically evaluated pretreatment conditions (e.g., MIBK/H2O ratio, reaction temperature and time, NaCl concentration, and HCl dosage) on the effect of furfural yield. The resulting solid fraction obtained from the optimum pretreatment condition for furfural yield was to produce fermentable glucose by enzymatic hydrolysis. Study on enzymatic hydrolysis of the raw material and resulting solid fraction obtained by single aqueous system was also contrastively investigated. The furfural yield was 65.9% and the recovery of residue was 46.9% under an optimal reaction condition (VMIBK:VH2O = 5:5, 150 °C, 60 min, 0.3 M HCl). Meanwhile, the yield of glucose of cellulose was improved after the pretreatments with different systems and a maximum value was up to 60.2% by the MIBK/H2O pretreatment. The effective fermentable glucose production was mainly affected by the significant removal of hemicelluloses, change of CrI, and destruction of surface morphology of Eucalyptus. The MIBK/H2O pretreatment can be considered as a potential approach for efficient conversion of Eucalyptus to clean energy and biochemicals.
[en] Polyester (PET) is one of the hydrophobic fibers. Disperse dyes are the most important dyestuff for dyeing of this fibers. Dyeing can be applied by carrier, H T and the thermo fix methods. In this research, hydrolyzed polyester fibers by lipase in different conditions are dyed by disperse and ionic dyes in using various methods. The results of dyeing by disperse dyes show that the enzymatic hydrolysis increases the surface rate of dyeing but being non-effective on final adsorption of dyes. On the contrary dyeing with ionic dyes indicated that no adsorption of these dyes (acid and cationic dyes) takes place on hydrolyzed fibers
[en] Enzymatic hydrolysis of polyester fabrics has been investigated, using different treatment times, temperature and concentration of enzymes. The effects of hydrolysis on samples were evaluated by measurement of weight loss, moisture regain, breaking load of warp yarns, thickness and Ftir spectroscopy. Results show that hydrolysis under mild conditions can improve moisture absorption of the samples. If the applied temperature, treatment time and concentration exceeded some specific range, the moisture regain would be affected negatively. The Ftir spectrums showed an increase in functional groups specially hydroxyl. However the effects of enzymatic hydrolysis on weight loss, tensile strength and thickness of polyester fabrics were negligible
[en] The hydrolysis of sucrose via enzymatic was evaluated using a spherical bed packed reactor. The experimentation was divided into three stages. First, the invertase enzyme is immobilized on 100 grams of support for two particle sizes between 60-80 mesh and 100-140 mesh. A 2 x 3 block design was carried out with 2 treatments and 3 blocks, as variables of volumetric flow design (treatments) at the levels of 2 mL/min and 3 mL/min and initial concentration of sucrose (blocks) of 0,75 mol/L, 1,00 mol/L and 1,25 mol/L and the volumetric flow of 2 mL/min and 3 mL/min, in the second stage. The conversion rate of sucrose in reducing sugars was the response variable. A factorial design of three variables and two levels was applied in the third stage. The sucrose concentration of 1,00 mol/L and 1,25 mol/L, the volumetric flow of 2 mL/min and 4 mL/min and a temperature of 50 degrees Celsius and 55 degrees Celsius were the levels of the design variables. The effect of temperature as well as the interaction concentration of sucrose-volumetric flow and the interaction concentration of sucrose-temperature were statistically significant. The quality analysis of the obtained product was checked by a test of the best reaction conditions determined in the previous stages
[es]La hidrolisis de sacarosa via enzimatica fue evaluada utilizando un reactor esferico de lecho empacado. La experimentacion fue dividida en tres etapas. Primero, la enzima invertasa es inmovilizada en 100 gramos de soporte para dos tamanos de particula entre malla 60-80 y malla 100-140. Se realizo un diseno de bloques 2 x 3 con 2 tratamientos y 3 bloques, como variables de diseno de flujo volumetrico (tratamientos) a los niveles de 2 mL/min y 3 mL/min y concentracion inicial de sacarosa (bloques) de 0,75 mol/L, 1,00 mol/L y 1,25 mol/L y el flujo volumetrico de 2mL/min y 3 mL/min, en la segunda etapa. El porcentaje de conversion de sacarosa en azucares reductores fue la variable de respuesta. Un diseno factorial de tres variables y dos niveles, fue aplicado en la tercera etapa. La concentracion de sacarosa de 1,00 mol/L y 1,25 mol/L, el flujo volumetrico de 2 mL/min y 4 mL/min y una temperatura de 50 grados centigrados y 55 grados centigrados fueron los niveles de las variables de diseno. El efecto de la temperatura asi como de la interaccion concentracion de sacarosa-flujo volumetrico y la interaccion concentracion de sacarosa-temperatura fueron estadisticamente significativas. El analisis de calidad del producto obtenido fue comprobado por un ensayo a las mejores condiciones de reaccion determinadas en las etapas anteriores
[en] Amyloglucosidase (E.C. 184.108.40.206) from Aspergillus niger was used to hydrolyze the sago (Metro xylon sagu) starch into reducing sugars. The experiment was conducted at constant temperature, 55 degree Celsius; pH, 4.5 and enzyme amount, 0.2 U/ ml, respectively. In this investigation, the substrate concentration was varied ranging from 1.0 - 7.0 g/ L. The obtained data were then fixed into linearized plots namely Lineweaver-Burk and Langmuir models to calculate enzyme kinetic parameters, Km and Vmax. Both of the Km and Vmax (mM, mol/min) values from each plot were: Lineweaver-Burk (26.53, 3.31) and Langmuir (13.52, 2.35). Among the linearized models, Km and Vmax values acquired from Langmuir plot was chosen. (author)
[en] Enzymatic hydrolysis is one of the leading approaches to producing ethanol from low cost biomass. Recent cost estimates suggest that ethanol produced from biomass could be competitive as a transportation fuel with gasoline at $20-25/BBL oil and less expensive than methanol. The process for making ethanol from biomass involves seven major steps: biomass production, pretreatment, enzyme production, enzymatic hydrolysis, fermentation, distillation, and by-product processing. Pretreatment makes the carbohydrate fraction of the biomass accessible to enzymatic attack. Cellulase enzymes are then used to hydrolyze the carbohydrates in biomass into fermentable sugar. The sugar is then fermented to ethanol and the ethanol purified by distillation. Three major cost estimates are available for making ethanol from biomass using a steam explosion pretreatment and enzymatic hydrolysis. These studies began with very different assumptions and as a result came to dramatically different conclusions about ethanol cost. When they are normalized to the same basis, however, their consensus is an expected ethanol cost of $1.64 ± 0.23/gal using technology implemented at Iogen's pilot plant in 1986. Since that time, technology advances have reduced the expected cost of ethanol to $0.77 ± 0.17/gal. Further technical improvements could reduce the cost by as much as $0.23/gal