No abstract

The effect of single-walled carbon nanotubes (SWCNTs) on the formation and eradication of biofilms of activated sludge proteobacteria and actinobacteria of the genus Rhodococcus was studied. It has been shown that SWCNTs do not inhibit the formation of biofilms of these bacteria and do not cause their destruction, while in the presence of SWCNTs, much more massive biofilms of Alcaligenes faecalis 2 and Acinetobacter guillouiae 11h are formed. It was shown that the level of dehydrogenase activity, estimated by the reduction of tetrazolium salt to formazan, in biofilm cells formed in the presence of SWCNTs, exceeded that of biofilms in the control.

The effect of purified and unpurified multi-walled carbon nanotubes on the biofilm formation of Esche-richia coli strains isolated from different sources has been studied. It has been shown that carbon nano-materials in the culture medium do not inhibit biofilm formation, but on days 1–3 of growth lead to the formation of more massive biofilms of some strains. Significantly more intense destruction of mature bio-films of E. coli K12, E. coli K12 TG1 (pXen7) and one natural strain in the presence of carbon nanotubes in the medium was noted. No clear dependence of biofilm formation and destruction of formed biofilms on the degree of purification of nanotubes was found.