Time course of production of pectolytic enzymes by pathotypes of choanephora cucurbitarum. – E. J. Umana , B. E. Madunagu, S. E. Udo2 and A. A . Markson
ABSTRACT
The in vitro and in vivo production of pectolytic enzymes by three pathotypess of Choanephora cucurbitrarum isolated from Amaranthus hybridus, Vigna uguiculata and Abelmoschus esculentus were investigated. The amount of enzymes produced by the three pathotypes of Choanephora cucurbitarum varied with the age of culture. Also, the optimum pH of enzymes activity in each pathotype varied with the length of the incubation period. For Abelmoschus pathotype, highest enzymes level of 25RVU was produced on the six day old culture filtrate while for the nine day old filtrate, maximum enzyme level was 14RVU. With filtrate from 12, 15 and 18 days old cultures, optimum enzymes level were 17, 15 and 22RVU respectively. Result on Amaranthus pathotype showed that on three day old culture, activity was 5RVU at pH 3.0, 14RVU at pH 4.0, 14RVU at pH 5.0 and 0 at pH 9.0. Six day old culture was observed to have activity of 12RVU at pH 3.0, 75RVU at 4.0, 72RVU at pH 5.0 and 14RVU at pH 9.0 .There was a steady decline on the ninth day. Increase in activity was observed in 12, 15, and 18 day old cultures at pH 4.0 and pH 9.0. With the Vigna pathotypes, the enzymes production was optimal on the ninth day with 67 RVU and least in the 18 day old culture with 5RVU. Maximum activity was at pH 4.0 and least at pH 8.0.