The relative effects of some elements on the DNS method in cellulase assay

Abstract

For evaluating the relative effects of some polluting salts on the measurement of cellulase activity assayed by 3,5-dinitrosalicylate (DNS) this study was done. Glucose were the most effective inhibitors of cellulase activity. These ions inhibited exoglucanase more than endoglucanase. The effect of most ions on cellulase activity may be related to negative or positive effect of them on the method of cellulase assessment. So, for a better data interpretation in the study of ion effects on the soil enzyme activity, both the effects of ions on the method of enzyme assay, and the effects of ions on the enzyme activity should be studied. @JASEM Cellulase is an enzyme system that degrades cellulose and releases reducing sugars as the end products. The system consists of endo-l,4-B-glucanase (EC3.2.1.4), exo-I,4-B-glucanase (EC 3.2.1.91) and B-Dglucosidase (EC 3.2.1.21). Endo-α -1,4-glucanase (1,4-α-D-glucan-4-glucan-hydrolase) has the role of randomly degrading α-1,4-glucosidic bonds from the middle of the cellulose molecule. It does not attack cellobiose but hydrolyzes cellodextrines and substituted celluloses, for instance carboxymethylcellulose. Its specificity is moderate, different sub-types having various affinities for different length oligosaccharides. Exo-β-1,4-glucanase (1,4-β -D-glucan cellobiohydrolase) cuts step by step cellobiose units from the non-reducing end of cellulosic chains. It hydrolyses the cellodextrines but not the cellobiose. Its substrate specificity is rather high enabling it to degrade more than 80% from the crystalline cellulose while its degree of activity is different for different microorganisms.

Different elephant grass ( Pennisetum purpureum ) accessions as substrates for enzyme production for the hydrolysis of lignocellulosic materials

“…According to Sinegani and Emtiazi [27], exoglucanase activity increased in the presence of Ca þ2 and Ba þ2 salts but decreased in the presence of Na þ , K þ , NH 4 þ and Mg þ2 salts. However, these results may be related to the effect of these cations on the methods of cellulase assessment.…”

“…They are not as readily complexed with trace metals as those involving sulfhydryl groups [27]. b i o m a s s a n d b i o e n e r g y 7 1 ( 2 0 1 4 ) 1 5 5 e1 6 1…”

STATISTICAL OPTIMIZATION OF MINERAL SALT AND UREA CONCENTRATION FOR CELLULASE AND XYLANASE PRODUCTION BY Penicillium echinulatum IN SUBMERGED FERMENTATION

“…Sinegani and Emtiazi (2006) . According to the present study, it seems that, when high concentrations of salts are employed, possible salt residues can be found in the final broth, interfering with enzymatic analysis.…”

Enzymatic hydrolysis of cellulose in a membrane bioreactor: assessment of operating conditions

“…Literature on the role and characterization of various cellulase components has been reviewed by different authors [26,27]. As reported by Sinegani and Emtiazi [28], the presence of Na ? salts increased endoglucanase activity, but decreased exoglucanase activity synchronously.…”