{Reference Type}: Journal Article
{Author}: Zheng, Fei; Ding, Shaojun
{Year}: 2013
{Title}: Processivity and enzymatic mode of a glycoside hydrolase family 5 endoglucanase from Volvariella volvacea
{Tag}: 5
{Star}: 0
{Place Published}: 1752 N Street N.W., Washington, DC 20036-2904, United States
{Journal}: Applied and Environmental Microbiology
{Volume}: 79
{Issue}: 3
{Pages}: 989-996
{Date Displayed}: 2013
{ISBN/ISSN}: 00992240
{Original Publication}: American Society for Microbiology
{Keywords}: Enzymes; Adsorption; Carbohydrates; Cellulose; Desorption; Substrates
{Abstract}: EG1 is a modular glycoside hydrolase family 5 endoglucanase from Volvariella volvacea consisting of an N-terminal carbohydrate-binding module (CBM1) and a catalytic domain (CD). The ratios of soluble to insoluble reducing sugar produced from filter paper after 8 and 24 h of exposure to EG1 were 6.66 and 8.56, respectively, suggesting that it is a processive endoglucanase. Three derivatives of EG1 containing a core domain only or additional CBMs were constructed in order to evaluate the contribution of the CBM to the processivity and enzymatic mode of EG1 under stationary and agitated conditions. All four enzymatic forms exhibited the same mode of action on both soluble and insoluble cellulosic substrates with cellobiose as a main end product. An additional CBM fused at either the N or C terminus reduced specific activity toward soluble and insoluble celluloses under stationary reaction conditions. Deletion of the CBM significantly decreased enzyme processivity. Insertion of an additional CBM also resulted in a dramatic decrease in processivity in enzyme-substrate reaction mixtures incubated for 0.5 h, but this effect was reversed when reactions were allowed to proceed for longer periods (24 h). Further significant differences were observed in the substrate adsorption/desorption patterns of EG1 and enzyme derivatives equipped with an additional CBM under agitated reaction conditions. An additional family 1 CBM improved EG1 processivity on insoluble cellulose under highly agitated conditions. Our data indicate a strong link between high adsorption levels and low desorption levels in the processivity of EG1 and possibly other processive endoglucanses.   2013, American Society for Microbiology.
{Notes}: Compilation and indexing terms, Copyright 2013 Elsevier Inc.
20130615988804
Adsorption/desorption
C terminus
Carbohydrate-binding modules
Catalytic domains
Cellobiose
Cellulosic substrates
End-products
Endoglucanases
Filter papers
Glycoside hydrolases
Mode of action
N-terminals
Processivity
Reaction conditions
Reaction mixture
Reducing sugars
Specific activity
Strong link
Volvariella volvacea
{Author Address}: Department of Biological Engineering, Nanjing Forestry University, Nanjing, Jiangsu, China

{Reference Type}: Journal Article
{Author}: Arce-Cervantes, O.; Mendoza, G.; Miranda, L. A.; Meneses, M.; Loera, O.
{Year}: 2013
{Title}: Efficiency of Lignocellulolytic Extracts from Thermotolerant Strain Fomes sp EUM1: Stability and Digestibility of Agricultural Wastes
{Tag}: 0
{Star}: 0
{Journal}: JOURNAL OF AGRICULTURAL SCIENCE AND TECHNOLOGY
{Volume}: 15
{Issue}: 2
{Pages}: 229-240
{ISBN/ISSN}: 1680-7073
{Keywords}: SOLID-STATE FERMENTATION; PLEUROTUS-OSTREATUS IE8; IN-VITRO DIGESTIBILITY; ENZYME-PRODUCTION; CHEMICAL-COMPOSITION; FIBROLYTIC ENZYMES; NITROGEN-SOURCE; WHEAT-STRAW; GROWTH; DEGRADATION; Enzymatic extracts; Fungal thermotolerance; in vitro gas production; Solid state cultures
{Abstract}: Production of lignocellulolytic enzymes by the thermotolerant Fomes sp. EUM1 was determined in solid cultures using corn stover (CS) as a sole substrate or supplemented with 20 % wheat bran (CS+WB). This supplementation increased (P < 0.05) enzymatic activity per gram of initial dry matter (gdm) for xylanases and cellulases: 160 IU g dm(-1) and 37 IU g dm(-1), respectively; while laccases reached a similar yield (3.3 IU g dm(-1)) for both cultures. Nevertheless, laccases showed different stability patterns at 39 degrees C and pH 6: half-life time (t(1/2)) was doubled in extracts from CS+WB (23.5 h); whereas t(1/2) for the other enzymes from both cultures showed no difference. Both extracts by Fomes sp. EUM1 and a commercial enzymatic product were used on forages: corn stover, (CS), sugarcane bagasse (SCB), and alfalfa hay (AH). The fractional rate of gas production (FR; ml g(-1) h(-1)) increased (P < 0.05) at 9 hours in CS compared to the sample without enzymes. The use of any enzymes favoured higher maximum gas volume (Vm; h(-1)) on SCB. The in vitro digestibility (IVD) of CS after using the commercial product was 12% higher, while our extracts from CS and CS+WB showed 16 and 21% improvements (P < 0.05), respectively, suggesting a higher specificity of these enzymes produced on the same substrate (CS). In addition to the proven stability, the versatility of extracts from CS and CS+WB was confirmed by the increase in IVD values for SCB (up to 100%) in relation to the control without enzymes.
{Author Address}: Metropolitan Autonomous Univ Iztapalapa, Dept Biotechnol, Mexico City 09340, DF, Mexico; Metropolitan Autonomous Univ Xochimilco, Dept Agr Anim Prod, Mexico City 04969, DF, Mexico; Chapingo Autonomous Univ, Dept Zootech, Texcoco 56235, Mexico; Postgrad Coll, IREGEP, Montecillo 56230, Texcoco, Mexico; Metropolitan Autonomous Univ Iztapalapa, Dept Biotechnol, Mexico City 09340, DF, Mexico
{Database Provider}: Web of Science SCI
{Language}: English
{Country}: Mexico; Mexico; Mexico; Mexico

{Reference Type}: Journal Article
{Author}: Birhanli, Emre; Erdogan, Selim; Yesilada, Ozfer; Onal, Yunus
{Year}: 2013
{Title}: Laccase production by newly isolated white rot fungus Funalia trogii: Effect of immobilization matrix on laccase production
{Tag}: 0
{Star}: 0
{Journal}: BIOCHEMICAL ENGINEERING JOURNAL
{Volume}: 71
{Pages}: 134-139
{ISBN/ISSN}: 1369-703X
{Keywords}: ENHANCED PRODUCTION; ACTIVATED CARBON; TEXTILE DYES; WASTE-WATER; PLEUROTUS-OSTREATUS; TRAMETES-PUBESCENS; DECOLORIZATION; PELLETS; FERMENTATION; Activated carbon; Enzymes; Enzyme production; Fermentation; Filamentous fungi; Laccase
{Abstract}: The laccase production performance of newly isolated Funalia trogii (F. trogii) immobilized on low-cost activated adsorbents prepared from apricot stone was investigated in inexpensive molasses medium and compared with free pellets. The adsorbents were apricot stone-based activated carbon (AC), Cu-impregnated apricot stone-based activated carbon (Cu-AC) and Fe-impregnated apricot stone-based activated carbon (Fe-AC). Cu-AC and Fe-AC were prepared by chemical activation. The values of BET surface area (S-BET), total pore volume (V-t), micropore surface area (S-mic) and micropore volume (V-mic) which show the pore properties of the activated carbons were 133 m(2) g(-1), 0.105 cm(3) g(-1), 108 m(2) g(-1) and 0.056 cm(3) g(-1) for Cu-AC and 145 m(2) g(-1), 0.112 cm(3) g(-1), 117 m(2) g(-1) and 0.061 cm(3) g(-1) for Fe-AC, respectively. F. trogii attached well on all of these adsorbents. However, the fungus immobilized on Cu-AC produced much higher levels of laccase than the others. The laccase activity obtained in 5 g L-1 molasses media after first cycle and mean laccase activity obtained after three cycles with fungus immobilized on Cu-AC were 29.23 U mL(-1) and 27.04 U mL(-1), respectively. These activities were only 0.25 and 0.39 U mL(-1) with free pellets. The crude laccase from immobilized culture could also decolorize the textile dyes. (c) 2012 Elsevier B.V. All rights reserved.
{Author Address}: Inonu Univ, Arts & Sci Fac, Dept Biol, TR-44280 Malatya, Turkey; Inonu Univ, Arts & Sci Fac, Dept Chem, TR-44280 Malatya, Turkey; Inonu Univ, Arts & Sci Fac, Dept Biol, TR-44280 Malatya, Turkey; Inonu Univ, Fac Engn, Dept Chem Engn, TR-44280 Malatya, Turkey
{Database Provider}: Web of Science SCI
{Language}: English
{Country}: Turkey; Turkey; Turkey