Simple bacterial preservation medium and its application to proficiency testing in water bacteriology

Area of Science:

• Microbiology
• Environmental Science
• Analytical Chemistry

Background:

• Maintaining bacterial culture viability is crucial for laboratory testing and research.
• Standard methods for bacterial preservation can be time-consuming and require specific conditions.
• Escherichia coli is a key indicator organism in water quality assessments.

Purpose of the Study:

• To develop and evaluate a cost-effective preservation medium for Escherichia coli.
• To assess the stability of Escherichia coli in the developed medium under ambient conditions.
• To validate the utility of the preservation medium in a practical water bacteriology proficiency test.

Main Methods:

• Formulation of a preservation medium with nutrient broth, 1.8% boric acid, and 1% sodium chloride at pH 7.0.
• Incubation of Escherichia coli cultures in the medium at room temperature for up to 10 days.
• Preparation of simulated water samples using preserved cultures for a proficiency test survey.

Main Results:

• The developed medium successfully maintained the stability of Escherichia coli cultures for a period of 10 days at room temperature.
• The preservation medium facilitated the accurate performance of a water bacteriology proficiency test survey.
• No significant loss of bacterial viability was observed within the 10-day preservation period.

Conclusions:

• The nutrient broth-based medium with boric acid and sodium chloride offers a stable and practical solution for preserving Escherichia coli.
• This preservation technique is suitable for use in routine water quality monitoring and proficiency testing.
• The findings support the use of this medium for ensuring reliable results in water bacteriology.