Authors:V. Jurkovich, J. Kutasi, Hedvig Fébel, J. Reiczigel, E. Brydl, L. Könyves, and P. Rafai
A study was conducted to obtain data on the effects of a fungal fibrolytic enzyme preparation (Rumino-zyme, with 250 FXU/g xylanase activities) from Thermomyces lanuginosus on some rumen fermentation parameters in sheep. Ruminal fluid samples were taken just before the morning feeding and then 2 h and 4 h after feeding. Xylanase activity, pH, concentration of ammonia and volatile fatty acids were measured. The enzyme supplementation did not affect the pH but increased the xylanase activity and the total VFA concentration of the rumen fluid. The molar proportion of acetate increased, propionate was not affected and butyrate decreased after enzyme administration. The concentration of ammonia also decreased after supplementation with the enzyme product. It can be concluded that the xylanase enzyme preparation from T. lanuginosus induced favourable changes in the major rumen fermentation parameters in sheep.
Authors:Y. Bakri, Y. Akeed, M. Jawhar, and M.I.E Arabi
Xylanase (EC184.108.40.206) is an industrially important enzyme that hydrolyzes xylan by breaking the hemicelluloses of the plant cell wall and produces xylooligosaccharides, xylobiose, and xylose ( B eg et al., 2001 ; P aes et al., 2012 ). This
Anand, L., Krishnamurthy, S., Vithayathil, P. J. (1990) Purification and properties of xylanase from the thermophilic fungus, Humicola lanuginosa Griffon and Maublanc Bunce. Arch. Biochem. Biophys. 276 , 546
Authors:J. Kutasi, Á. Bata, E. Brydl, P. Rafai, and V. Jurkovich
This paper describes the production of an enzyme preparation from the fungus Thermomyces lanuginosus. Thermal resistance, pH stability and lignocellulolytic activity of the enzyme preparation high in xylanase were studied on a variety of grains and forages. The enzyme preparation preserved more than 70% of its original xylanase activity for 4 and 1 h at 60 and 70 °C, respectively. The xylanase activity remained over 80% when the preparation was incubated for 30 min at pH 4.5. In vitro digestibility studies indicated that the enzyme digested 7.5, 8.5 and 8.0% of the dry matter (DM) of barley meal, wheat bran and oat meal samples, respectively. When applying 60-min incubation, 7.5, 7.3 and 8.4% of DM of the oat straw, alfalfa hay and triticale straw was digested, respectively. When the time of digestion was increased to 360 min, the sunflower hull showed 15.8% DM digestibility.
Authors:U. Comlekcioglu, E. Ozkose, F. Yazdic, I. Akyol, and M. Ekinci
Akyol, I., Comlekcioglu, U., Kar, B., Ekinci, M. S., Ozkose, E. (2009) Cloning of a xylanase gene
from rumen fungus
sp. GMLF2 in
and its partial characterization.
Authors:S.M. Fiszman, P. Varela, A. Salvador, A. Gámbaro, A. Giménez, G. Ares, E. Wittig De Penna, L. López, and M.E. López
Three independent studies were conducted in Chile, Spain and Uruguay to assess the effects of the addition of enzymes on the shelf life of brown pan bread.Four batches of brown bread were prepared in each country: a control batch with no added enzymes, a second batch with amylase, a third batch with xylanase and a fourth batch with a 1:1 mixture of amylase and xylanase. Three sensory texture parameters were evaluated (softness, size of the soft area and cohesiveness) and a consumer study was conducted to determine the acceptability of the samples. In each country, the doses of each enzyme and enzyme mixtures (1:1) added to doughs have to be adapted to obtain good dough handling characteristics and minimise adhesiveness and stickiness of the corresponding flour in the traditional formulation.In all three countries the addition of the enzyme mixture gave the best results, achieving a longer shelf life, while the addition of xylanase accelerated bread staling.
Authors:Balázs Lemmer, Szabolcs Kertész, Gábor Keszthelyi-Szabó, Kerime Özel, and Cecilia Hodúr
Membrane separation processes are currently proven technologies in many areas. The main limitation of these processes is the accumulation of matter at the membrane surface which leads to two phenomena: concentration polarization and membrane fouling. According to the publications of numerous authors permeate flux could be increased by sonication. Our work focuses on separation of real broth by sonicated ultrafiltration. The broth was originated from hydrolysis of grounded corn-cob by xylanase enzyme. The filtration was carried out in a laboratory batch stirred cell with a sonication rod sonicator. In our work the effect of the stirring, the intensity of sonication and the membrane-transducer distance was studied on the efficiency of the ultrafiltration and on the quality of separated enzymes. Results reveal that xylanase enzyme can be effectively separated from real fermentation broth by ultrafiltration and enzymes keep their activity after the process. Enzyme activity tests show that low energy sonication is not harmful to the enzyme.
Authors:T. Prokopov, M. Nikolova, G. Dobrev, and D. Taneva
Enzyme-assisted extraction of carotenoids from tomato peels of the Bulgarian cultivar “Stela”, one of the most widely used cultivars by the canning industry, was examined in this study. The carotenoid content in raw tomato peels was established by HPLC analysis. A two-step protocol was followed: the tomato peels were first treated with enzymes and then extracted by the use of acetone as a solvent for 30 min at 20±1 °C and solid/liquid ratio of 1:30. The total carotenoid, lycopene, and β-carotene extraction yields were increased by the use of pectinase, cellulase, endo-xylanase, and proteinase enzymes in comparison with the non-enzyme-treated samples. The increase in the extraction yield was affected by the enzymes used, the enzyme concentration, the pretreatment time and temperature. Maximum total carotenoid (55.15 mg/100 g d.w.), β-carotene (35.85 mg/100 g d.w.), and lycopene (15.44 mg/100 g d.w.) extraction yields were obtained in peels pretreated with mixed cellulase (100 U g−1) and endo-xylanase (400 U g−1) for 4 h at 50 °C. Carotenoid recovery by mixed cellulolytic and hemi-cellulolytic enzyme pretreatment of tomato peels is a good approach, which can be used for waste utilization.
Authors:C. Roets, S.H. Rose, M. Muller, and M. Manley
The effect of a pure endoxylanase (Xyn2) and endoglucanase (EgII) from Trichoderma reesei on bread flour quality were compared to a commercial endoxylanase from Aspergillus niger (Com-xyl) and a cellulase-xylanase cocktail from T. reesei (Cel-xyl). Effects of these enzymes on dough quality, bread weight, height and crumb softness were analysed. Results obtained during commercial-scale baking tests often differed from those obtained during laboratory-scale tests; indicating that results from laboratory-scale baking tests cannot be extrapolated to commercialscale bread production. Low levels of endoxylanase activity benefited bread height and volume without affecting slice brightness in commercial-scale tests. The addition of endoglucanases and α-amylases can also be advantageous resulting in less endoxylanase activity required to obtain similar results.