The use of surface microdischarge (SMD) for the bacterial decontamination of raw produce was evaluated. With 1 min of SMD treatment, >2 logarithmic reduction in
- Award ID(s):
- 1923534
- NSF-PAR ID:
- 10310706
- Editor(s):
- Guichard, P.; Hamel, V.
- Date Published:
- Journal Name:
- Methods in cell biology
- Volume:
- 161
- ISSN:
- 0091-679X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract Escherichia coli O157:H7 was consistently observed. The scanning electron microscopy ofE. coli O157:H7 show that SMD damages the cell membrane, leads to cell expansion, and eventually lysis. The attenuated total reflectance‐Fourier‐transform infrared spectroscopy characterization ofE. coli O157:H7 and lipopolysaccharides (LPS) shows that SMD causes (a) the oxidation of cellular components by forming COOH and COO−groups inside and on the cell wall, and (b) the modification of polysaccharides and phosphorus‐containing groups found in phospholipids and DNA. Further characterization with X‐ray photoelectron spectroscopy suggests SMD mainly modifies the O‐chain and core‐polysaccharide part of LPS. -
Abstract Background and Aims Endosidins are a group of low-molecular-weight compounds, first identified by ‘chemical biology’ screening assays, that have been used to target specific components of the endomembrane system. In this study, we employed multiple microscopy-based screening techniques to elucidate the effects of endosidin 5 (ES5) on the Golgi apparatus and the secretion of extracellular matrix (ECM) components in Penium margaritaceum. These effects were compared with those caused by treatments with brefeldin A and concanamycin A. Penium margaritaceum’s extensive Golgi apparatus and endomembrane system make it an outstanding model organism for screening changes to the endomembrane system. Here we detail changes to the Golgi apparatus and secretion of ECM material caused by ES5.
Methods Changes to extracellular polymeric substance (EPS) secretion and cell wall expansion were screened using fluorescence microscopy. Confocal laser scanning microscopy and transmission electron microscopy were used to assess changes to the Golgi apparatus, the cell wall and the vesicular network. Electron tomography was also performed to detail the changes to the Golgi apparatus.
Key Results While other endosidins were able to impact EPS secretion and cell wall expansion, only ES5 completely inhibited EPS secretion and cell wall expansion over 24 h. Short treatments of ES5 resulted in displacement of the Golgi bodies from their typical linear alignment. The number of cisternae decreased per Golgi stack and trans face cisternae in-curled to form distinct elongate circular profiles. Longer treatment resulted in a transformation of the Golgi body to an irregular aggregate of cisternae. These alterations could be reversed by removal of ES5 and returning cells to culture.
Conclusions ES5 alters secretion of ECM material in Penium by affecting the Golgi apparatus and does so in a markedly different way from other endomembrane inhibitors such as brefeldin A and concanamycin A.
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