Gellan gum as a substitute for agar in leptospiral media

Abstract

An albumin polysorbate semisolid medium (Ellinghausen McCullough Johnson Harris medium) gelled with gellan gum (Geirite; Kelco Div., Merck & Co., Inc.) compared favorably with conventional agar media for the cultivation of both pathogenic and saprophytic leptospires. The gellan gum medium supported the growth of all 18 leptospiral strains studied which included an array of serovars with various fastidious growth characteristics. Gellan gum medium was also used advantageously as a long-term maintenance medium; 9-to 12-month-old cultures still contained viable organisms. The colonial growth in gellan gum plating medium of six representative strains was consistent with previously described colonial growth on agar plating media. In addition, gellan gum medium appeared to be an excellent medium for the recovery of leptospires from the blood, liver, and kidneys of hamsters experimentally infected with a virulent Leptospira interrogans serovar bataviae strain. As few as 1 to 10 organisms in the infective tissue could be recovered in semisolid Ellinghausen McCullough Johnson Harris-gellan gum medium. The antigenicity did not appear to be affected by growth in gellan gum medium. The hamster-virulent strain of L. interrogans serovar bataviae isolated from a moribund hamster maintained its virulence after 10 sequential passages in gellan gum medium. Gellan gum medium can be a valuable adjunct to currently used cultural procedures.

Microbial diversity with dominance of 16S rRNA gene sequences with high GC contents at 74 and 98 °C subsurface crude oil deposits in Japan

“…We also attempted to isolate bacterial and archaeal species from the production water of #AR39 oil deposit by cultivation. We isolated two bacterial strains and one archaeon at 75 1C under atmospheric pressure and anaerobic conditions using Gellan gum medium (Rule & Alexander, 1986) in roll tubes (Eller et al, 1971), from among 15 bacterial and five archaeal strains detected by the molecular method using 16S rRNA gene sequences, respectively. Bacteria were isolated in TBSY medium, Thermotoga basal medium containing 0.5% soluble starch and 0.05% yeast extract (Childers et al, 1992) under O 2 -free N 2 gas and the archaeon was isolated using McN medium (Kim & Whitman, 1999) under H 2 -CO 2 (80 : 20) gas.…”

Highly Concentrated Alginate-Gellan Gum Composites for 3D Plotting of Complex Tissue Engineering Scaffolds

“…Since the discovery of gellan gum, an anionic polysaccharide produced by the bacteria Sphingomonas paucimobilis , it has found wide spread applications in food industry as a gelling/stabilizing agent and also in plant and bacterial culture systems [1,2,3,4]. In the recent decades, its suitability for tissue engineering approaches has been studied because of its versatile gelling properties, i.e.…”

An Initial Evaluation of Gellan Gum as a Material for Tissue Engineering Applications

“…The main medical application to date has been for controlled drug delivery both as an encapsulating agent [12] and as an active ingredient in an ophthalmic formulation that gels on exposure to the tear film, thus ensuring the medications remain suitably located in the eye [13]. Gellan has been used in plant tissue culture [14,15], bacterial culture [16] and has been evaluated as a component of a composite material for mammalian TE [17,18]. However, there have been no reports of gellan being used exclusively for the immobilization and culture of mammalian cells.…”