Effect of Sodium Fluoride on Growth and Some Enzymatic Activities of Four Bacteria Pathogenic to Melons PDF

Keywords

sodium fluoride, bacteria, melons, enzymes

Abstract

The effect of different concentrations of sodium fluoride on growth and the enzymatic activities, in vivo, of Erwinia carotovora var. carotovora; Erwinia carotovora var. citrullus; Erwinia toxica and Pseudomonas lachrymans was studied. The results show that E. toxica seemed to be highly tolerant to sodium fluoride (LD50 at 10^-2 M), followed by P. lachrymans and E. carotovora var. carotovora whereas E. carotovora car. citrullus was most sensitive. Neither glutamic acid decarboxylase nor lysine decarboxylase was detected in the four pathogens, but arginine decarboxylase was present in E. carotovora var. citrullus. Its activity decreased with increased sodium fluoride concentration and ceased at 10^-1 M. Sodium fluoride inhibited alkaline and acid phosphatase of E. toxica and P. lachrymans. Such effect was only apparent at 10^-3 M or above for E. carotovora var. carotovora or at 10^-2 M or above for E. carotovora var. citrullus. Lower concentrations seemed without effect for the former but were stimulatory for the latter organism. Sodium fluoride did not induce the production of the proteolytic or asparaginase enzymes.