Characterizing Bacillus globigii as a Bacillus anthracis surrogate for wastewater treatment studies and bioaerosol emissions

Abstract

This study characterized Bacillus globigii (BG) as a Bacillus anthracis Sterne (BAS) surrogate for wastewater treatment-related studies of UV inactivation, adsorption onto powdered activated carbon (PAC), and bioaerosol emission. The inactivation of BG was faster than that of BAS in DI water (pseudo first-order rate constants of 0.065 and 0.016 min⁻¹ respectively) and in PBS solution (0.030 and 0.005 min⁻¹ respectively). BG was also removed more quickly than BAS by PAC adsorption in DI (0.07 and 0.05 min⁻¹ respectively) and in PBS (0.09 and 0.04 min⁻¹ respectively). In DI, BG aggregated more (P < 0.05) than BAS when the pH was 7 or greater but there were no statistically significant differences in NaCl solution. Spore aggregation was also studied with extended Derjaguin–Landau–Verwey–Overbeek (XDLVO) models. Less than 1% of all spores were released as bioaerosols, and there was no significant difference (P > 0.05) in emission between BG and BAS. To the author's knowledge, this study is the first to demonstrate that BG is a suitable surrogate for BAS for bioaerosol emissions, but a poor surrogate for both UV inactivation and PAC adsorption. These results can be used to understand the ability of BAS to act as a surrogate for BA Ames because of its genetic and morphological similarities with BAS.