New and highly active microbial phosphotriesterase sources.

Area of Science:

• Environmental Science
• Biotechnology
• Biochemistry

Background:

• Organophosphorus compounds, including insecticides and chemical warfare agents, pose significant environmental and health risks.
• Bioremediation using phosphotriesterases offers an effective and eco-friendly detoxification method.
• Identifying novel phosphotriesterases is crucial for advancing bioremediation strategies.

Purpose of the Study:

• To discover novel bacterial phosphotriesterases with high catalytic activity.
• To evaluate the impact of temperature on the enzymatic hydrolysis rates of identified phosphotriesterases.
• To compare the performance of newly identified strains with a known reference strain.

Main Methods:

• A fluorimetric screening method on solid media was utilized to identify bacterial strains exhibiting phosphotriesterase activity.
• Enzymatic hydrolysis rates were assessed at varying temperatures to determine optimal conditions.
• Activity levels were quantified and compared against the reference strain *Brevundimonas diminuta*.

Main Results:

• Six bacterial strains with phosphotriesterase activity were successfully isolated.
• Significant increases in phosphotriesterase activity were observed at elevated temperatures (50°C) for *Nocardia asteroides* and *Streptomyces setonii*.
• *Nocardia asteroides* and *Streptomyces setonii* showed 7-fold and 30-fold activity increases, respectively, compared to 30°C, and 26-fold and 75-fold increases compared to *Brevundimonas diminuta*.

Conclusions:

• Novel bacterial strains, particularly *Nocardia asteroides* and *Streptomyces setonii*, possess highly active phosphotriesterases suitable for bioremediation.
• Optimizing temperature is critical for enhancing the efficiency of organophosphorus compound detoxification.
• These findings contribute to the development of more effective biocatalysts for environmental cleanup.