Share

Transmission electron microscopy of unfrozen and frozen-thawed cells of Listeria monocytogenes treated with lipase and lysozyme.

Author(s) : KEST S. E. el-, MARTH E. H.

Type of article: Article

Summary

Unfrozen cells of Listeria monocytogenes typically contained no preplasma space exterior to the plasma membrane when viewed by transmission electron microscopy. Cells of L. monocytogenes strains Scott A, V7, and California (CA), after freezing and frozen storage, exhibited one or more of the 3 described phenomena. Type and degree of effect depended on frozen storage time and strain of L monocytogenes. The effect of lysozyme treatment of unfrozen or frozen/stored (19 d)/thawed cells is studied. Three stages of protoplast formation were observed when cells of strain CA were frozen, stored 2 weeks, thawed, and treated with lysozyme. Damage to the plasma membrane increased with increasing frozen storage time for up to 6 weeks. Some cells of strain CA resisted freezing, frozen storage for 6 weeks, thawing, and treatment with lipase and lysozyme.

Details

  • Original title: Transmission electron microscopy of unfrozen and frozen-thawed cells of Listeria monocytogenes treated with lipase and lysozyme.
  • Record ID : 1993-1689
  • Languages: English
  • Source: Journal of Food Protection - vol. 55 - n. 9
  • Publication date: 1992/09
  • Document available for consultation in the library of the IIR headquarters only.

Links


See the source

Indexing