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

Abstract

Two strains of gliding, orange-pigmented bacteria, isolated from fresh bell pepper and watermelon, respectively, showing soft-rot lesions, were identified as Cytophaga johnsonae. They differed from seven type strains of C. johnsonae deposited at the American Type Culture Collection (ATCC) in some properties, such as the ability to utilize glucose, xylose, trehalose, rhamnose, and sucrose. Spherical bodies resembling microcysts of Sporocytophaga sp. in addition to short rods and long filaments were observed in two strains (ATCC 29583 and 29588) throughout the growth cycle and also in aged cultures of other strains. All strains examined were shown to degrade five natural or synthetic polymers (pectin, chitin, starch, protein, and carboxymethyl cellulose). Only six strains (including ATCC 17061, 29587, 29589, and 19366) were able to infect and macerate artificially wounded potato tubers and fruits of pepper, squash, and tomato. The pathogenic strains secreted more pectate lyase in broth medium than the nonpathogenic strains. C. johnsonae, generally known as a soil saprophyte, might occasionally act as an opportunistic pathogen, causing decay of fresh produce in storage or in transit.

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

“…ccampestris (17,24), and C. johnsoniae (13,16,35) have focused on the detection and inducibility of the enzymes. Results presented in this study provide further information about the isoelectric properties, Mrs, and tissue-macerating abilities of PLs produced by the organisms listed above.…”

“…Purified or partially purified PL samples from six representative strains of soft rot bacteria were compared for their abilities to macerate potato tuber. Potato slices were prepared as described previously (16,17), except that the slices were treated with 30 pg of kanamycin per ml before they were placed onto 0.6% agar plates. Each slice was inoculated with 5 pIl of an enzyme sample containing 0.1 to 5.0 U of PL activity.…”

“…Activities of PL have been detected previously in culture supernatants of diverse groups of soft rot bacteria (20), including Erw'inia spp. (27,34,36), Pseililoilnotiias fliuor-escenis (or Pseiudoinlo-n1as inar-ginialis) (7,9,10,23,37), Pseiuldoinzon)ais 51ridflaviai (10,15), Xcanthomonas calmpestris (17,24), and Cvtop/haga johnisonsae (13,16,35). The PL produced by Ertl'inia spp.…”

Association of Pectolytic Strains ofXanthomonas campestriswith Soft Rots of Fruits and Vegetables at Retail Markets

“…For long-term preservation, a low-salt collected. Properties of the first four of these genera have been medium containing beef extract (1%), proteose peptone (1%), and reported in depth elsewhere (16,17). This paper details the cultural, agar (0.9%) was stab-inoculated with bacteria and subsequently physiological, and pathological properties of five strains of yellowoverlaid with a layer (2-3 cm) of sterile mineral oil.…”

Cell-associated amylase activity in Cytophaga johnsonae

“…Cytophaga spp. are saprophytic bacteria found commonly in soil (Reichenbach & Dworkin 1981), on decaying plant material (Liao & Wells 1986) and in aerobic waste treatment facilities (Gude 1980). Enzymes secreted by Cytophaga spp.…”