THERMOSTABILIZATION OF <i>Eupenicillium erubescens</i> AND <i>Cryptococcus albidus </i>α-L-RHAMNOSIDASES BY CHEMICAL REAGENTS
The aim of the research was a comparative study of the thermal stability of native and modified by various methods α-L rhamnosidases of <i>Eupenicillium erubescens </i>and <i>Cryptococcus albidus </i>for improving the stability of enzymes. Denaturation of native and modified enzymes were performed at 65 C, pH 5.2. Enzyme activity was determined using p -nitrophenyl-α-L-rhamnopyranoside and naringin. It is found that in the treatment by polyethylenglycol PEG 1500, dextrans 500 and 70 T thermostability of α-Lrhamnosidases tested decreases, while modification with polyethylenglycol 20000 leads to increase thermal stability of the E. <i>erubescens </i>enzyme to 280% and C. <i>albidus </i>to 150%. Comparative study of the thermal stability of the native and modified by cellulose and its derivatives α-L-rhamnosidases of C. <i>albidus </i>and E. <i>erubescens </i>showed that at concentrations cellulose of 5-15 μg / 10 μg protein protective effect of polymers on enzymes was investigated was observed. Hydrophobic modifications using succinic anhydride also can slow down the denaturation of α-L-rhamnosidases tested under experimental conditions. These stabilized C. <i>albidus </i>and E. <i>erubescens </i>-α-L- rhamnosidases can be used in biotechnological processes.