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Kamgang-Youbi G Herry JM Brisset JL Bellon-Fontaine MN Doubla A Naïtali M 《Applied microbiology and biotechnology》2008,81(3):449-457
This paper describes the effects of initial microbial concentration and planktonic/adherent/detached states on the efficiency
of plasma-activated water. This disinfecting solution was obtained by treating distilled water with an atmospheric pressure
plasma produced by gliding electric discharges in humid air. The inactivation kinetics of planktonic cells of Hafnia alvei (selected as a bacterial model) were found to be of the first order. They were influenced by the initial microbial concentration.
Efficiency decreased when the initial viable population N
0 increased, and the inactivation rate k
max was linearly modified as a function of Log10 (N
0). This relation was used to compare planktonic, adherent, and detached cells independently from the level of population.
Bacteria adhering to stainless steel and high-density polyethylene were also sensitive to treatment, but at a lower rate than
their free-living counterparts. Moreover, cells detached from these solid substrates exhibited an inactivation rate lower
than that of planktonic cells but similar to adherent bacteria. This strongly suggests the induction of a physiological modification
to bacteria during the adhesion step, rendering adherent—and further detached—bacteria less susceptible to the treatment,
when compared to planktonic bacteria. 相似文献
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Two new reducing glycoconjugates [N-D-galacturonoyl-putrescinamide (GalA-Put) and N,N'-di-D-galacturonoyl-putrescinamide (GalA-Put-GalA)] and homogalacturonan-putrescine (GalAn-Put) conjugates were synthesised as model compounds representing possible amide (isopeptide) linkage points between a polyamine and either one or two pectic galacturonate residues. The amide bond(s) were stable to cold acid and alkali (2M TFA and 0.1M NaOH at 25 degrees C) but rapidly hydrolysed by these agents at 100 degrees C. The amide bond(s) were resistant to Driselase and to all proteinases tested, although Driselase digested GalAn-Put, releasing fragments such as GalA3-Put-GalA3. To trace the possible formation of GalA-polyamine amide bonds in vivo, we fed Arabidopsis and rose cell-cultures and chickpea internodes with [14C]Put. About 20% of the 14C taken up was released as 14CO2, indicating some catabolism. An additional approximately 73% of the 14C taken up (in Arabidopsis), or approximately 21% (in rose), became ethanol-insoluble, superficially suggestive of polysaccharide-Put covalent bonding. However, much of the ethanol-inextractable 14C was subsequently extractable by acidified phenol or by cold 1M TFA. The small proportion of radioactive material that stayed insoluble in both phenol and TFA was hydrolysable by Driselase or hot 6M HCl, yielding 14C-oligopeptides and/or amino acids (including Asp, Glu, Gly, Ala and Val); no free 14C-polyamines were released by hot HCl. We conclude that if pectin-polyamine amide bonds are present, they are a very minor component of the cell walls of cultured rose and Arabidopsis cells and chickpea internodes. 相似文献
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