The optoelectronic properties of gold nanoparticles make them ideal for use in technological and biomedical applications. The expansion of gold nanoparticle applications motivates improvement in designing functionalized nanoparticles. The impact of such engineered nanoparticles on organisms in the environment, such as bacteria, is not well understood at the molecular level. To investigate the interactions between gold nanoparticles and Gram-positive bacteria, three Bacillus subtilis strains differing in wall teichoic acid composition (SB491 being the wild type, tagE lacking glucose and dltA lacking d-alanine moieties) were exposed to cationic b-PEI-functionalized gold nanoparticles (bPEI-AuNPs). Characterization of bacterial whole cell surface charges of the three strains show that the tagE mutant has the most negative overall surface charge. Upon exposure to the gold nanoparticles, the extent of interaction with the three strains differed as demonstrated by fluorescence-assisted cell sorting (FACS), while toxicity assessments showed no significant difference among them. The extent of gold nanoparticle attachment was largest to the tagE mutant, suggesting electrostatic interaction between cell wall material and gold nanoparticles dictates extent of association. The results of this work will help the engineering of gold nanoparticles in a way that makes them less impactful when exposed to organisms in the environment.

Molecular interaction between b-PEI-functionalized gold nanoparticles and Bacillus subtilis strains varying in wall teichoic acid composition

255th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.