In:
Applied and Environmental Microbiology, American Society for Microbiology, Vol. 70, No. 11 ( 2004-11), p. 6800-6808
Abstract:
Aluminum and bisulfite salts inhibit the growth of several fungi and bacteria, and their application effectively controls potato soft rot caused by Erwinia carotovora . In an effort to understand their inhibitory action, ultrastructural changes in Erwinia carotovora subsp. atroseptica after exposure (0 to 20 min) to different concentrations (0.05, 0.1, and 0.2 M) of these salts were examined by using transmission electron microscopy. Plasma membrane integrity was evaluated by using the SYTOX Green fluorochrome that penetrates only cells with altered membranes. Bacteria exposed to all aluminum chloride concentrations, especially 0.2 M, exhibited loosening of the cell walls, cell wall rupture, cytoplasmic aggregation, and an absence of extracellular vesicles. Sodium metabisulfite caused mainly a retraction of plasma membrane and cellular voids which were more pronounced with increasing concentration. Bacterial mortality was closely associated with SYTOX stain absorption when bacteria were exposed to either a high concentration (0.2 M) of aluminum chloride or prolonged exposure (20 min) to 0.05 M aluminum chloride or to a pH of 2.5. Bacteria exposed to lower concentrations of aluminum chloride (0.05 and 0.1 M) for 10 min or less, or to metabisulfite at all concentrations, did not exhibit significant stain absorption, suggesting that no membrane damage occurred or it was too weak to allow the penetration of the stain into the cell. While mortality caused by aluminum chloride involves membrane damage and subsequent cytoplasmic aggregation, sulfite exerts its effect intracellularly; it is transported across the membrane by free diffusion of molecular SO 2 with little damage to the cellular membrane.
Type of Medium:
Online Resource
ISSN:
0099-2240
,
1098-5336
DOI:
10.1128/AEM.70.11.6800-6808.2004
Language:
English
Publisher:
American Society for Microbiology
Publication Date:
2004
detail.hit.zdb_id:
223011-2
detail.hit.zdb_id:
1478346-0
SSG:
12
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