Rapid Method for Estimating Polyhydroxybutyrate Accumulation in Bacteria Using Sodium Hypochlorite

Area of Science:

• Microbiology
• Biochemistry
• Analytical Chemistry

Background:

• Polyhydroxybutyrate (PHB) is a biopolymer accumulated by many bacteria.
• Accurate quantification of PHB is crucial for understanding bacterial physiology and optimizing bioprocesses.
• Existing methods for PHB quantification can be time-consuming and require specialized equipment.

Purpose of the Study:

• To establish and validate a fast and simple protocol for estimating PHB accumulation in bacterial cells.
• To assess the feasibility of using sodium hypochlorite (NaClO) extraction for semi-quantitative PHB measurement.
• To evaluate the correlation of the NaClO method with established PHB quantification techniques.

Main Methods:

• Bacterial cultures of *Halomonas titanicae* KHS3, *Alteromonas* sp., and *Cobetia* sp. were used.
• PHB was extracted using a sodium hypochlorite (NaClO) method.
• Spectrophotometric measurement of extracted PHB turbidity was employed for semi-quantitative estimation.
• Results were compared with dry cell weight, crotonic acid, and High-Performance Liquid Chromatography (HPLC) quantifications.

Main Results:

• The NaClO extraction method provided a rapid (within 50 minutes) and semi-quantitative estimation of PHB accumulation.
• The method showed good correlation with dry cell weight, crotonic acid, and HPLC-based PHB quantification.
• Visible differences in PHB content were observable even by the naked eye in samples with high or low accumulation levels.

Conclusions:

• The NaClO extraction protocol offers a fast, easy, and cost-effective way to estimate bacterial PHB accumulation.
• This method is valuable for optimizing culture conditions, monitoring PHB kinetics, and determining optimal harvest times.
• The protocol is applicable to various bacterial species, facilitating research in microbial biopolymer production.