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. 1980 Sep;40(3):596–607. doi: 10.1128/aem.40.3.596-607.1980

Fine Structure of Extracellular Polysaccharide of Erwinia amylovora†

D J Politis 1,‡, R N Goodman 1
PMCID: PMC291626  PMID: 16345638

Abstract

Virulent E9 and avirulent E8 strains of Erwinia amylovora were shown by means of light, transmission, and scanning microscopy to be, respectively, encapsulated and unencapsulated. Difficulty was encountered in stabilizing the fibrillar-appearing capsular extracellular polysaccharide. We suggest that the ephemeral nature of extracellular polysaccharide is due to the collapse of its extended structure upon dehydration. This occurs when bacteria are prepared for either transmission or scanning electron microscopy. The electron micrographs support our previous biochemical and immunological studies contending that the capsule is composed of tightly bound and loosely held components. The preparation of bacteria in freeze-dried colonies has permitted us to observe and explain the fluidity of the encapsulated strain. We suggest that this fluidity is a reflection of the loosely held extracellular polysaccharide or slime.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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