Purification and Characterization of β-Glucosidase from Aspergillus niger

Figures & data

TABLE 1 Summary of purification of β-glucosidase

Step	Total volume (mL)	Total protein (mg)	Total activity (U)	Specific activity (U/mg)	Yield (%)	Purification fold
Culture filtrate	100	120	84.0	0.70	100.0	1.0
Ammonoium sulphate precipitation	10	1.68	53.0	31.55	63.1	45.10
Sephadex G-75	11	0.50	30.3	60.60	36.1	86.50

Values represented in the tables are means of three separately conducted experiments.

FIGURE 1 Purification of β-glucosidase on sephadex G-75.

FIGURE 2 Determination of molecular mass of β-glucosidase from Aspergillus niger by SDS-PAGE. Lane 1: Protein markers phosphorylase (97 kDa), bovine albumin (66 kDa), ovalbumin (45 kDa), carbonic anhydrase (30 kDa), soybean trypsin inhibitor (20 kDa), and α-lactabumin (14 kDa). Lane 2: Purified enzyme.

FIGURE 3 Double reciprocal plot between initial rate of hydrolysis and substrate concentration.

FIGURE 4 Effect of pH on enzyme activity.

FIGURE 5 Effect of temperature on enzyme activity.

TABLE 2 Influence of effectors and inhibitors on β-glucosidase assay

Chemical	Relative activity over control (%)
MgSO4	100.00
Al203	40.10
AgNO3	69.15
HgC12	90.00
MnCl2	120.00
EDTA	100.00
Triton X-100	239.00
Tween-80	211.00
SDS	97.00
Methanol	180.00
Ethanol	130.00

The activity measured in the absence of a chemical (control) was considered 100%.