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Investigating the elongated cell phenotype of Escherichia coli o verexpressing the lysophospholipase PldB
Author(s) -
Georgiou George S.,
Garrett Teresa A.
Publication year - 2018
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2018.32.1_supplement.671.10
Subject(s) - escherichia coli , biology , plasmid , nucleoid , phosphatidylglycerol , glycerophospholipid , cell , phenotype , membrane , cell division , microbiology and biotechnology , biochemistry , phospholipid , dna , gene , phosphatidylcholine
The overexpression of the enzyme PldB leads to increased levels of the headgroup‐acylated glycerophospholipid, acyl phosphatidylglycerol (acyl PG), in the membranes of Escherichia coli. The role of acyl PG in E. coli has yet to be fully determined. Interestingly, PldB overexpression leads to an elongated phenotype, suggesting a role for acyl PG in cell length and division. To gain a better understanding of this phenotype, wildtype MG1655 and cells lacking the chromosomal pldB (ΔpldB) were transformed with an empty arabinose‐inducible plasmid (pBAD), and a plasmid containing pldB (pPldB). These four strains (MG1655/pBAD, MG1655/pPldB, Δ pldB /pBAD, and Δ pldB /pPldB) were grown to mid‐log phase and imaged via scanning electron microscopy. Quantification of cell lengths from SEM images showed a significant difference in the average length of the wild‐type strain, MG1655/pBAD (1.85 μm ± 0.46 μm), versus MG1655/pPldB (2.69 μm ± 1.12 μm) and Δ pldB /pPldB (3.02 μm ± 2.42 μm). Furthermore, many of the elongated cells appeared to contain no cleavage furrows suggesting that they failed to complete cellular division. Visualization of the chromosomal DNA by staining with DAPI revealed that PldB overexpressing strains contained multiple unsegregated nucleoids within individual cells, providing more evidence that PldB overexpression leads to irregularities in cellular division. Future research will focus on separation of the inner and outer membranes of E. coli overexpressing acyl‐PG in order to assess the lipid compositions of each respective membrane and elucidate where acyl‐PG migrates and integrates once formed. Additionally, the contractile Z‐ring of E. coli overexpressing acyl‐PG will be visualized via fluorescence microscopy to further investigate the relationship between acyl‐PG and cellular division. Support or Funding Information Supported by National Science Foundation Research at Undergraduate Institutions grant #1516805. This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .