Comparative study of the growth curves of B. subtilis, K. pneumoniae, C. xerosis And E. coli bacteria using nanometric silicon particles as a bacteriological sensor

摘要

In this research nanometric particles from luminescent (625nm) porous silicon film were synthesized. This particles were later inoculated in bacterial strains of B. subtilis (BSi) and K. pneumoniae (KSi). A comparison of the behavior of their growth curve and the ones reported for C. xerosis (XSi) and E. coli (ESi) in presence of silicon nanoparticles is presented. The growth curve of BSi, as well as the KSi, present changes compared to their standard curves. The BSi growth curve grows below the standard curve after the fifth hour, while in the KSi this happens after the eighth hour. Based on our preliminary findings we can speculate that at this point in time a critical population is present, and this may give rise to the possible incorporation of the silicon particles by the bacteria, or a possible pleomorphism inhibits reproduction. The stationary region, in both cases, takes place sooner than in the standard curve. No significant oscillations are observed in any case, which differs form the XSi curve, were oscillations of intervals of almost 1 hour were reported. In addition, these curves have a different behavior when compared to the ESi growth curve, in which no significant differences between the standard and the particle containing sample were reported.