scholarly journals Investigation of Escherichia coli in Urban Steam with Inflow of Treated Wastewater

2018 ◽  
Vol 41 (2) ◽  
pp. 19-26 ◽  
Author(s):  
Yoshihiro SUZUKI ◽  
Masateru NISHIYAMA ◽  
Kei NUKAZAWA ◽  
Satoshi ISHII
2000 ◽  
Vol 41 (7) ◽  
pp. 127-134 ◽  
Author(s):  
M. J. Casteel ◽  
M. D. Sobsey ◽  
M. J. Arrowood

Alternative disinfectants of water and wastewater are needed because conventional chlorination is ineffective against C. parvum oocysts. Reliable indicators of disinfection efficacy against C. parvum also are needed. Mixedoxidants (MO) electrochemically generated from brine were evaluated in batch disinfection experiments for inactivation of C. parvum oocysts and Cl. perfringensspores in both oxidant demand-free (ODF) water and treated wastewater. Coliphage MS2 and Escherichia coli B were also tested under some conditions. C. parvum oocyst infectivity was quantified by cell culture assay, and the dyes DAPI (4′,6-diamidino-2-phenylindole) and propidium iodide (PI) were used to assess oocyst viability in wastewater experiments. In treated wastewater dosed with 10–13 mg/L MO, inactivation after 90 minutes was about 3 log10 for C. parvum and about 2.5 log10 for Cl. perfringens spores; MS2 and E. coli were rapidly inactivated by > 5 log10. In ODF water, a 4 mg/L dose of MO inactivated ∼3 log10 of C. parvum oocysts and ∼1.5 log10 of Cl. perfringens spores. Inactivation of C. parvum oocysts and Cl. perfringensspores was less extensive at a lower MO dose of 2 mg/L. The use of DAPI and PI to determine viability of oocysts treated with MO did not correlate with, and greatly overestimated, cell culture infectivity. At practical doses and contact times, MO disinfection of water and wastewater achieves appreciable inactivation of both C. parvum oocysts and Cl. perfringens spores. Cl. perfringens spores reliably indicated oocyst inactivation by MO, but E. coli and coliphage MS2 were inactivated much too rapidly to indicate C. parvum inactivation.


Author(s):  
Manfred E. Bayer

Bacterial viruses adsorb specifically to receptors on the host cell surface. Although the chemical composition of some of the cell wall receptors for bacteriophages of the T-series has been described and the number of receptor sites has been estimated to be 150 to 300 per E. coli cell, the localization of the sites on the bacterial wall has been unknown.When logarithmically growing cells of E. coli are transferred into a medium containing 20% sucrose, the cells plasmolize: the protoplast shrinks and becomes separated from the somewhat rigid cell wall. When these cells are fixed in 8% Formaldehyde, post-fixed in OsO4/uranyl acetate, embedded in Vestopal W, then cut in an ultramicrotome and observed with the electron microscope, the separation of protoplast and wall becomes clearly visible, (Fig. 1, 2). At a number of locations however, the protoplasmic membrane adheres to the wall even under the considerable pull of the shrinking protoplast. Thus numerous connecting bridges are maintained between protoplast and cell wall. Estimations of the total number of such wall/membrane associations yield a number of about 300 per cell.


1966 ◽  
Vol 241 (13) ◽  
pp. 3090-3096
Author(s):  
Sally E. Jorgensen ◽  
James F. Koerner

1970 ◽  
Vol 245 (14) ◽  
pp. 3708-3715 ◽  
Author(s):  
Peter P.K. Ho ◽  
Elizabeth B. Milikin ◽  
Jesse L. Bobbitt ◽  
Edward L. Grinnan ◽  
Philip J. Burck ◽  
...  

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