Exploring the Influence of Various Treatments on the Autofluorescence Properties of Bacillus subtilis

BACKGROUND AND ABJECTIVEBacterial autofluorescence, characterized by the spontaneous emission of light without external fluorescent labels, offers a unique and non-invasive approach to investigate bacterial metabolic activities and physiological responses. In this study, we investigated the impact of different treatments on the autofluorescence of Bacillus subtilis, a versatile model organism widely utilized in biotechnology and research.MATERIALS AND METHODSThe effects of hydrogen peroxide (H۲O۲), heat, cold, ethanol, glucose deprivation, and acidic and alkaline conditions on the autofluorescence properties were evaluated. Treated samples were subjected to a ۱۰-minute exposure to ۳۶۵ nm ultraviolet (UV) light using a fluorescence microscope. Subsequently, the samples were evaluated using a Shimadzu RF- spectrofluorimeter with excitation wavelengths of ۳۶۵ nm and ۴۰۵ nm and emission wavelengths ranging from ۳۹۰ nm to ۹۰۰ nm.RESULTS AND DISCUSSIONOur findings demonstrated that acidic and alkaline conditions had minimal impact on the autofluorescence of B. subtilis. However, glucose deprivation and exposure to H۲O۲ led to a significant reduction in autofluorescence levels, up to ۶۰%. Conversely, ethanol exposure and heat treatment resulted in an increase of up to ۵۰%, while cold conditions induced a substantial ۱۰۰% increase. Furthermore, we analyzed the lysate and supernatant of B.subtilis to assess the presence of autofluorescence. Our results confirmed the presence of autofluorescence in both phases, with the lysate exhibiting significantly higher fluorescence levels compared to the supernatant.CONCLUSIONThese findings contribute to our understanding of the autofluorescence characteristics of B. subtilis and offer potential applications in fields such as fluorescence microscopy and spectrofluorimetry .

کلیدواژه ها:

Bacterial autofluorescence ، Bacillus subtilis ، treatment effect investigation