Determination of Cellulase Activity Using Hydroxyethylellulose as Substrate

1973 ◽  
Vol 51 (1) ◽  
pp. 39-43 ◽  
Author(s):  
J. J. Child ◽  
D. E. Eveleigh ◽  
A. S. Sieben
Keyword(s):  
Plant Cell ◽  
Correction Factor ◽  
Cellulase Activity ◽  
Viscosity Measurement ◽  
Assay System ◽  
Sensitive Assay ◽  
Low Levels

Nonionic celluloses are recommended to replace ionic celluloses as substrates in viscometric determinations of low levels of cellulase. A rapid, sensitive assay is described using hydroxyethylcellulose as substrate, and a correction factor is applied to compensate for deviations from linearity in viscosity measurement. The assay system has been used successfully for the measurement of low levels of extracellular and intracellular cellulases of both fungal and plant-cell origin.

A Sensitive Assay System for the Determination of Poly(L-Lysine) Concentration Using Turbidometry

1999 ◽  
Vol 14 (2) ◽  
pp. 122-136 ◽  
Author(s):  
Christopher M. Ward ◽  
Kerry D. Fisher ◽  
Leonard W Seymour
Keyword(s):  
Assay System ◽  
Sensitive Assay ◽  
Lysine Concentration

Quantitative Determination of Plasminogen

1970 ◽  
Vol 23 (02) ◽  
pp. 191-201 ◽  
Author(s):  
H. D Bruhn ◽  
L Müller ◽  
F Duckert
Keyword(s):  
Quantitative Determination ◽  
Plasminogen Activator ◽  
Assay System ◽  
Two Stage ◽  
System Activation ◽  
Frozen Plasma

SummaryA modification of the caseinolytic assay for plasminogen is described. This assay system is characterized by the following features :1. Urokinase is used as activator achieving a complete activation of the plasminogen whereas with streptokinase caseinolytically inactive plasminogen-activator complexes are formed.2. All incubation times are reduced to the minimum which is still compatible with accuracy.3. Results are expressed in percent of a standard of ten normal plasmas.4. In this two-stage assay-system (activation of plasminogen to plasmin, digestion of casein by plasmin) both stages proceed simultaneously in the same system, thus the plasmin formed is stabilized “in statu nascendi” by the casein.5. Several conditions (stability of plasminogen in frozen plasma, use of anticoagulants, reproducibility) are defined.

Spectrophotometric Determination of Raceophenidol in Feed at Very Low Levels

1968 ◽  
Vol 51 (4) ◽  
pp. 752-755
Author(s):  
Edward L Pratt ◽  
Morris E Auerbach
Keyword(s):  
Spectrophotometric Determination ◽  
Growth Promotion ◽  
Ultraviolet Spectrum ◽  
Average Value ◽  
Collaborative Studies ◽  
Low Levels ◽  
Concentration Levels

Abstract Raceophenidol in feed at concentration levels intended for growth promotion of poultry can be estimated by a curvature inversion measurement related to the ultraviolet spectrum of derived p-methylsulfonylbenzaldehyde. The drug can be accurately measured at the 0.0005% level. Collaborative studies on the method showed an average value of 94 ± 10% of claim. The method is recommended for adoption as official, first action.

Determination of low levels of bromide in fresh water after chromatographic enrichment

Talanta ◽  
1984 ◽  
Vol 31 (1) ◽  
pp. 45-48 ◽  
Author(s):  
Ulla Lundström ◽  
Åke Olin ◽  
Folke Nydahl
Keyword(s):  
Fresh Water ◽  
Low Levels

scholarly journals Synergistic Effect of Different Plant Cell Wall–Degrading Enzymes Is Important for Virulence of Fusarium graminearum

2017 ◽  
Vol 30 (11) ◽  
pp. 886-895 ◽  
Author(s):  
Maria Chiara Paccanaro ◽  
Luca Sella ◽  
Carla Castiglioni ◽  
Francesca Giacomello ◽  
Ana Lilia Martínez-Rocha ◽  
...  
Keyword(s):  
Cell Wall ◽  
Fusarium Graminearum ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Xylanase Activity ◽  
Cellulase Activity ◽  
Wild Type ◽  
Cell Wall Degrading Enzymes ◽  
Xylanase Production ◽  
Significant Difference

Endo-polygalacturonases (PGs) and xylanases have been shown to play an important role during pathogenesis of some fungal pathogens of dicot plants, while their role in monocot pathogens is less defined. Pg1 and xyr1 genes of the wheat pathogen Fusarium graminearum encode the main PG and the major regulator of xylanase production, respectively. Single- and double-disrupted mutants for these genes were obtained to assess their contribution to fungal infection. Compared with wild-type strain, the ∆pg mutant showed a nearly abolished PG activity, slight reduced virulence on soybean seedlings, but no significant difference in disease symptoms on wheat spikes; the ∆xyr mutant was strongly reduced in xylanase activity and moderately reduced in cellulase activity but was as virulent as wild type on both soybean and wheat plants. Consequently, the ΔpgΔxyr double mutant was impaired in xylanase, PG, and cellulase activities but, differently from single mutants, was significantly reduced in virulence on both plants. These findings demonstrate that the concurrent presence of PG, xylanase, and cellulase activities is necessary for full virulence. The observation that the uronides released from wheat cell wall after a F. graminearum PG treatment were largely increased by the fungal xylanases suggests that these enzymes act synergistically in deconstructing the plant cell wall.

Determination of Ochratoxin A in Feed by Immunoaffinity Cleanup and Liquid Chromatography

2013 ◽  
Vol 96 (3) ◽  
pp. 599-602 ◽  
Author(s):  
Ping Ding ◽  
Ziyou Mi ◽  
Yali Hou ◽  
Yigang He ◽  
Jianhua Xie
Keyword(s):  
Liquid Chromatography ◽  
Detection Limit ◽  
Ochratoxin A ◽  
Cyanogen Bromide ◽  
Polyclonal Antibodies ◽  
Immunoaffinity Column ◽  
Low Levels ◽  
Sepharose 4B ◽  
Feed Samples

Abstract A method using LC was developed for determination of ochratoxin A (OTA) in feeds. The extracted samples were cleaned up by an immunoaffinity column prepared by covalently coupling polyclonal antibodies against OTA to cyanogen bromide-activated Sepharose 4B. The eluates were determined by LC with fluorescence detection. Recoveries of OTA from fortified samples of 1–10 μg/kg levels ranged from 84.3 to 90.0%, with CVs of 3.3–7.8%. The detection limit was 0.045 μg/kg based on an S/N of 3:1. A total of 65 feed samples were screened for OTA with the proposed method. The results showed that only nine samples were contaminated with OTAs at low levels. The presented method was successfully applied to quantify OTAs in real feed samples.

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