Pectinase Production by Bacteria Associated with Improved Preservative Permeability in Sitka Spruce: Synthesis and Secretion of Polygalacturonate Lyase by Cytophaga johnsonii

Abstract

Cytophaga johnsonii synthesized a polygalacturonate lyase which produced random cleavage of galacturonic acid polymers. No pectin methyl‐esterase or hydrolytic pectinase activities could be detected in cultures of the organism. Polygalacturonate lyase synthesis was inducible and also subject to repression by glucose and other compounds. Galacturonic acid was the most effective inducer; lower activities were obtained with citrus pectin, polygalacturonic and polypectic acids. Glucose repression of lyase synthesis was not alleviated by 5 mM‐adenosine‐3′.5′‐cyclic‐monophosphate. Enzyme production was growth‐linked and ceased when batch cultures entered the stationary phase. In steady‐state chemostat cultures lyase activity was maximal at a dilution rate (D) of 0.19 h‐1. Polygalacturonate lyase was both cell‐bound and free in the supernatant medium. The proportion of free enzyme increased throughout the batch growth cycle and in chemostat cultures over 70% of the activity was cell free at dilution rates below 0.05 h‐1.

A Review: Maceration in Relation to the Post‐harvest Handling and Processing of Plant Material

“…Pectolytic bacteria have been isolated from the sap of submerged spruce poles (Fogarty & Ward 19726) and identified as strains of Bacillus subtilis, Cytophaga johnsonii (syn. C. johnsonae) and Flavobacterium pectinovorum Kurowski & Dunleavy 1976). F. pectinovorwn is now considered to be a strain of Cytophaga (Mitchell et al 1969).…”

“…Isolates were shown to increase permeability when inoculated into blocks of spruce in the laboratory (Dunleavy & Fogarty 1972). Endo-PAL was the sole activity produced by those isolates examined for pectic enzyme production (Ward & Fogarty 1973;Kurowski & Dunleavy 1976). Sap expressed from water-stored spruce also exhibited endo-PAL activity (Ward & Fogarty 1973).…”

Properties of Cytophaga johnsonae strains causing spoilage of fresh produce at food markets

“…Pectate lyase is believed to be the principal factor responsible for tissue maceration and development of soft-rot disease induced by Erwinia species and possibly Pseudomonas species (14). At present, very little is known about the pectic enzymes produced by C. johnsonae (6,8,20). Our results (Table 2) show that pectate lyase is produced by all strains of C. johnsonae examined.…”

A note on the pectinolytic enzyme of Streptococcus bovis

“…The cup-plate test for the presence of pectinesterase was negative confirming our earlier observation that the streptococci did not produce this enzyme (Wojciechowicz & Tomerska 1971). Kurowski & Dunleavy (1976) isolated a strain of Cytophaga johnsonii from water-stored Sitka spruce that also produced a polygalacturonate lyase but no pectinesterase.…”