SAFINUR YILDIRIM CELIK, YASAR DEMIR, NAZAN DEMIR AND MEDINE GÜLLÜCE
Abstract
Extracellular pectin lyase (EC 4.2.2.10) was produced by Xanthomonas campestris in solid state fermentation. Solid state fermentation was carried out using 250 mL Erlenmeyer flasks containing 5 g wheat bran, 1% citrus pectin and 10 mL salt mixture that composed of 0.14% (NH4)2SO4, 0.02% MgCl2 and 0.02% K2HPO4. Pectin lyase enzyme was purified 43 fold by using DEAE-cellulose anion exchange column chromatography and characterized. Molecular weight of the enzyme was determined as 77.5 kDa by using Sephadex G-100 gel filtration chromatography. Purification of enzyme was controlled by SDS-PAGE. The optimum pH and temperature of enzyme was determined as pH 9.0 and 50oC, respectively. Pectin lyase was mostly stable 40oC for 24 hours. KM and Vmax were calculated respectively as 0.69 mg/mL and 3.84 μmol/L*min. Purified pectin lyase was inhibited by Fe3+, Zn2+, Ca2+, Co2+ and Hg2+ except for Cu2+ and Mg2+. The purified pectin lyase enzyme was used for getting fruits juices. It was determined that yields of fruits juices improved when it was compared with control.