Analysis of pectate lyases produced by soft rot bacteria associated with spoilage of vegetables

Abstract

Isoelectric focusing (IEF) profiles of pectate lyases (PLs) produced by five different groups of soft rot bacteria were analyzed by using the combined techniques of thin-layer polyacrylamide gel IEF and agarose-pectate overlay activity staining. Four strains of soft rot Erwinia spp. produced three or more PL isozymes. All of eight Pseudomonas viridiflava strains examined produced one single PL with a pl of 9.7. All 10 of Pseudomnotas fluorescens strains produced two PLs; the major one had a p1 of 10.0 and the minor one had a pl of 6.7. A single PL with a pl of-10.0 was detected in one strain each of Xanthomonas campestris and Cytophaga johnsonae. PLs of six representative strains were purified from culture supernatants by ammonium sulfate precipitation and anion-exchange chromatography. All purified PL samples macerated potato slices, but to different degrees. The Mrs of alkaline PLs produced by P. viridiflava, P. fluorescens, X. campestris, and C. johnsonae were estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to be 42,000, 41,000, 41,500, and 35,000, respectively. IEF profiles of PLs were distinct among the bacterial species. Profiles of non-Erwinia spoilage bacteria were considerably simpler than those of Erwinia spp. The PL with an alkaline pl appeared to be the principal or the sole enzymatic factor involved in tissue maceration caused by most strains of soft rot bacteria.

Pectolytic enzymes produced by Pseudomonas syringae pv. glycinea

“…glycinea strain NCPPB 2411 produced in vitro two alkaline PL forms, PL1 (pI 9.0) and PL2 (pI 9.5), and one alkaline PG (pI 8.5). The presence of alkaline PLs secreted by soft rot bacteria has been well documented by several authors [4,[18][19][20][21][22][23]. Also, the dominant PLs were found to be alkaline in several phytopathogenic fungi [24][25][26][27].…”

“…Also, the dominant PLs were found to be alkaline in several phytopathogenic fungi [24][25][26][27]. The akaline isoenzymes appear to attack pectin polymers in a random manner and seem to be more destructive to plant tissues [17,18]. In a few cases, pectolytic activity produced by bacteria that do not cause soft rot has been reported.…”

Pectinase Activity of Vegetable Spoilage Bacteria in Modified Atmosphere

“…However, the ability of X. cumpestris pv. campestris to produce PL and PG was reported by Dow et al (1987) and Liao (1989).…”

“…Procedures for quantification of extracellular and intracellular enzymes were as described previously (Chatterjee et al, 1985;Lei et al, 1985;Liao, 1989;Lanham et al, 1991). A modified method of PECTINASE ACTMTY OF SPOILAGE BACTERIA.…”

Disrupção das ORFs XF-810, XF-818, XF-1940, XF-2359 e XF-2708 de >i<Xylella fastidiosa>/i<-CVC possivelmente relacionadas à patogenicidade da bactéria

“…Em Erwinia chrysanthemi, nove pectato liases extracelulares foram identificadas (Bekri et ai., 1999). Enquanto em todas as linhagens de Pseudomonas viridiflava estudadas por Liao (1989) uma única enzima péctica é necessária para a maceração do tecido vegetal, sendo esta uma pectato liase.…”