Premium
SOME CHARACTERISTICS OF AN ENDO‐PECTATE LYASE PRODUCED BY A THERMOPHILIC BACILLUS ISOLATED FROM OLIVES
Author(s) -
KARBASSI A.,
LUH B. S.
Publication year - 1979
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1365-2621.1979.tb03471.x
Subject(s) - pectate lyase , pectin , chemistry , ammonium sulfate precipitation , pectin lyase , enzyme , hydrolysis , softening , biochemistry , thermophile , chromatography , cellulose , pectinase , food science , size exclusion chromatography , statistics , mathematics
An endo pectate lyase (PAL), or endo‐pectic acid transeliminase secreted by a thermophilic Bacillus sp., responsible for softening in pickled olives, was purified 30‐fold by ammonium sulfate precipitation and successive chromatography on Bio‐gel P‐100, DEAE‐cellulose, and CM‐cellulose columns. It degraded both pectic acid and pectin N.F. in a random manner, but did not attack fully esterified Link pectin. The end products of its action on polygalacturonic acid were largely unsaturated di‐ and tri‐galacturonic acids, with smaller amounts of saturated di‐ and tri‐galacturonic acids. Both saturated and unsaturated pentra‐ and tetra‐galacturonic acids were cleaved by the enzyme. Addition of either the culture or the isolated enzyme to the pickled olives caused softening of the tissue within a week at 37°C when a Chatillon spring punch (0.064 in.) was applied. The activation energy of this heat‐stable pectate lyase enzyme on 0.5% pectic acid was 17.1 kcal/mole, and the Q 10 value was 2.35 between 60 and 70°C. The enzyme had a V max at 0.56 μmoles reducing groups/min and K m at 0.34% polygalacturonic acid.