Titanium Dioxide Solar Photocatalytic Microbial Inactivation Assessment Utilizing Viability Tests and a Novel Triplex...

Area of Science:

• Environmental Science
• Microbiology
• Chemical Engineering

Background:

• Photocatalytic oxidation offers a promising disinfection method for diverse water types.
• Current inactivation assessments rely on culturability, which misses metabolically active pathogens.
• There is a need for advanced methods to evaluate photocatalytic disinfection efficacy.

Purpose of the Study:

• To develop and validate a novel multiplex quantitative PCR (qPCR) assay for assessing photocatalytic inactivation of various microorganisms.
• To compare the efficacy of a new molecular assay with traditional microbiological methods.
• To evaluate the degradation of released nucleic acids as an indicator of photocatalytic damage.

Main Methods:

• Development of a multiplex qPCR assay for simultaneous detection of bacterial DNA, fungal DNA, and MS2 bacteriophage.
• Application of solar titanium dioxide photocatalysis to a mixed microbial suspension.
• Assessment of microbial inactivation using conventional culture-based methods and the novel qPCR assay.

Main Results:

• Microbiological assays confirmed significant microbial viability reduction within one hour.
• The novel qPCR assay demonstrated a reduction in released nucleic acids due to oxidative degradation within six hours.
• The assay successfully targeted diverse biopathogen classes, including bacteria, fungi, and viruses.

Conclusions:

• The developed multiplex qPCR assay is a valuable tool for evaluating photocatalytic disinfection efficiency.
• This molecular approach complements traditional methods by assessing nucleic acid integrity and degradation.
• The assay shows potential for both laboratory research and real-world wastewater treatment applications.