scholarly journals Resistance of bacterial cultures to non-oxidising water treatment bactericides by adaptation

1995 ◽  
Vol 31 (5-6) ◽  
pp. 169-175 ◽  
Author(s):  
V. S. Brözel ◽  
B. Pietersen ◽  
T. E. Cloete
Keyword(s):  
Water Treatment ◽  
Bacterial Communities ◽  
Bacterial Resistance ◽  
Water Cooling ◽  
Cooling Systems ◽  
Bacterial Cultures ◽  
Dimethyl Ammonium Chloride ◽  
Dimethyl Ammonium ◽  
Pure Cultures ◽  
Selection For

Bacterial communities in water cooling systems treated with bactericides often become resistant to these bactericides. This has been ascribed to selection for resistant cells. Certain bacteria, having a high inherent susceptibility to water treatment bactericides become dominant in systems after bactericide treatment. We investigated the idea that bacterial isolates adapt to grow in the presence of bactericides. Pure cultures of Pseudomonas aeruginosa, P stutzeri and Bacillus cereus were cultured repeatedly in the presence of sub-inhibitory concentrations of 2,2′-methylenebis(4-chlorophenol), Na dimethyldithiocarbamate, isothiazolone and alkyl dimethyl ammonium chloride. All isolates adapted to grow in the presence of increasing concentrations of the bactericides. The phenomenon of development of bacterial resistance to water treatment bactericides was ascribed to adaptation and not to selection.

scholarly journals New indicator reaction for kinetic determination of micro amounts of Sn(II)

2001 ◽  
Vol 66 (9) ◽  
pp. 631-636
Author(s):  
Rangel Igov ◽  
Violeta Mitic ◽  
Todor Pecev ◽  
Vesna Stankov-Jovanovic
Keyword(s):  
Kinetic Equation ◽  
Ammonium Chloride ◽  
Crystal Violet ◽  
Reaction Rate ◽  
Kinetic Determination ◽  
Inhibiting Effect ◽  
Dimethyl Ammonium Chloride ◽  
Concentration Interval ◽  
Dimethyl Ammonium

A new reaction is suggested and a new method is elaborated for determination of micro amounts of Sn(II) based on its inhibiting effect on the oxidation of {4-bis[n-(dimethylamino) phenyl]methylene-2,5-cyclohexadiene-1-ilydene}dimethyl-ammonium chloride (crystal violet CV) by H2O2. The method sensibility is 0.4 ?g/cm3. The probable relative error is 2.8-12.8 % for Sn(II) in the concentration interval of 3 to 0.8 ?g/cm3. The kinetic equation for this process is given. The influence of some other ions on the reaction rate was tested. The method was applied to the determination of Sn(II) in a sample of microalloy.

A Test of the Efficacy of a Ballast Water Treatment System Aboard the Vessel Coral Princess

2007 ◽  
Vol 44 (01) ◽  
pp. 57-67
Author(s):  
David A. Wright ◽  
Rodger Dawson ◽  
Celia E. Orano-Dawson ◽  
Sharon M. Moesel
Keyword(s):  
Water Treatment ◽  
Ballast Water ◽  
Panama Canal ◽  
Regulatory Agencies ◽  
Maritime Industry ◽  
Point Selection ◽  
Testing Procedures ◽  
Fort Lauderdale ◽  
Ballast Water Treatment ◽  
Selection For

Tests of the efficacy of a combination filtration/ultraviolet (UV) ballast water treatment (BWT) system were conducted aboard the MV Coral Princess during normal operations from Victoria, British Columbia, through the Panama Canal, to Fort Lauderdale, Florida. Trials were designed to assist the maritime industry in the deployment of effective BWT systems and to inform regulatory agencies on the feasibility of testing procedures and end-point selection for compliance standards. Results showed treatment efficacy at least equivalent to ballast water exchange, although adjustment of current published standards was indicated.

Enhanced water oxidation of CoP/CNTs via interfacial charge transfer induced by poly dimethyl diallyl ammonium chloride

2020 ◽  
Vol 44 (47) ◽  
pp. 20520-20524
Author(s):  
Yuxue Dai ◽  
Peng Gao ◽  
Xueying Wang ◽  
Pengfei Wang ◽  
Dandan Gao ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Charge Transfer ◽  
Ammonium Chloride ◽  
Alkaline Solution ◽  
Water Oxidation ◽  
Functionalized Carbon Nanotubes ◽  
Dimethyl Ammonium Chloride ◽  
Dimethyl Ammonium ◽  
Interfacial Charge ◽  
Diallyl Dimethyl Ammonium Chloride

CoP layer was successfully deposited onto poly(diallyl dimethyl ammonium chloride) (PDDA) functionalized carbon nanotubes (CoP/PDDA@CNTs) as high effective OER electrocatalysts in alkaline solution.

scholarly journals Broadscale phage therapy is unlikely to select for widespread evolution of bacterial resistance to virus infection

2020 ◽  
Vol 6 (2) ◽  
Author(s):  
Frederick M Cohan ◽  
Matthew Zandi ◽  
Paul E Turner
Keyword(s):  
Bacterial Resistance ◽  
Phage Therapy ◽  
Patient Treatment ◽  
Resistant Bacteria ◽  
Bacterial Populations ◽  
Recent Success ◽  
Adaptive Value ◽  
Global Spread ◽  
Classic Approach ◽  
Selection For

Abstract Multi-drug resistant bacterial pathogens are alarmingly on the rise, signaling that the golden age of antibiotics may be over. Phage therapy is a classic approach that often employs strictly lytic bacteriophages (bacteria-specific viruses that kill cells) to combat infections. Recent success in using phages in patient treatment stimulates greater interest in phage therapy among Western physicians. But there is concern that widespread use of phage therapy would eventually lead to global spread of phage-resistant bacteria and widespread failure of the approach. Here, we argue that various mechanisms of horizontal genetic transfer (HGT) have largely contributed to broad acquisition of antibiotic resistance in bacterial populations and species, whereas similar evolution of broad resistance to therapeutic phages is unlikely. The tendency for phages to infect only particular bacterial genotypes limits their broad use in therapy, in turn reducing the likelihood that bacteria could acquire beneficial resistance genes from distant relatives via HGT. We additionally consider whether HGT of clustered regularly interspaced short palindromic repeats (CRISPR) immunity would thwart generalized use of phages in therapy, and argue that phage-specific CRISPR spacer regions from one taxon are unlikely to provide adaptive value if horizontally-transferred to other taxa. For these reasons, we conclude that broadscale phage therapy efforts are unlikely to produce widespread selection for evolution of bacterial resistance.

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